From patchwork Thu Nov 21 09:53:50 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tali Perry X-Patchwork-Id: 1198846 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-i2c-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=gmail.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 47JZfk6GdKz9sPc for ; Thu, 21 Nov 2019 20:54:54 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726454AbfKUJyx (ORCPT ); Thu, 21 Nov 2019 04:54:53 -0500 Received: from 212.199.177.27.static.012.net.il ([212.199.177.27]:45268 "EHLO herzl.nuvoton.co.il" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726170AbfKUJyw (ORCPT ); Thu, 21 Nov 2019 04:54:52 -0500 Received: from taln60.nuvoton.co.il (ntil-fw [212.199.177.25]) by herzl.nuvoton.co.il (8.13.8/8.13.8) with ESMTP id xAL9rxwM021980; Thu, 21 Nov 2019 11:54:00 +0200 Received: by taln60.nuvoton.co.il (Postfix, from userid 20088) id 99F3660328; Thu, 21 Nov 2019 11:53:59 +0200 (IST) From: Tali Perry To: robh+dt@kernel.org, mark.rutland@arm.com, yuenn@google.com, venture@google.com, benjaminfair@google.com, avifishman70@gmail.com, joel@jms.id.au, tmaimon77@gmail.com, wsa@the-dreams.de, syniurge@gmail.com Cc: linux-i2c@vger.kernel.org, openbmc@lists.ozlabs.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Tali Perry Subject: [PATCH v7 2/2] i2c: npcm: Add Nuvoton NPCM I2C controller driver Date: Thu, 21 Nov 2019 11:53:50 +0200 Message-Id: <20191121095350.158689-3-tali.perry1@gmail.com> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20191121095350.158689-1-tali.perry1@gmail.com> References: <20191121095350.158689-1-tali.perry1@gmail.com> MIME-Version: 1.0 Sender: linux-i2c-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org Add Nuvoton NPCM BMC i2c controller driver. Signed-off-by: Tali Perry --- drivers/i2c/busses/Kconfig | 11 + drivers/i2c/busses/Makefile | 1 + drivers/i2c/busses/i2c-npcm7xx.c | 2485 ++++++++++++++++++++++++++++++ 3 files changed, 2497 insertions(+) create mode 100644 drivers/i2c/busses/i2c-npcm7xx.c diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 146ce40d8e0a..9091b93aaf90 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -786,6 +786,17 @@ config I2C_NOMADIK I2C interface from ST-Ericsson's Nomadik and Ux500 architectures, as well as the STA2X11 PCIe I/O HUB. +config I2C_NPCM7XX + tristate "Nuvoton I2C Controller" + depends on ARCH_NPCM7XX + select I2C_SLAVE + help + If you say yes to this option, support will be included for the + Nuvoton I2C controller. + + This driver can also be built as a module. If so, the module + will be called i2c-npcm7xx. + config I2C_OCORES tristate "OpenCores I2C Controller" help diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 3ab8aebc39c9..4af59a806f3c 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -81,6 +81,7 @@ obj-$(CONFIG_I2C_MT7621) += i2c-mt7621.o obj-$(CONFIG_I2C_MV64XXX) += i2c-mv64xxx.o obj-$(CONFIG_I2C_MXS) += i2c-mxs.o obj-$(CONFIG_I2C_NOMADIK) += i2c-nomadik.o +obj-$(CONFIG_I2C_NPCM7XX) += i2c-npcm7xx.o obj-$(CONFIG_I2C_OCORES) += i2c-ocores.o obj-$(CONFIG_I2C_OMAP) += i2c-omap.o obj-$(CONFIG_I2C_OWL) += i2c-owl.o diff --git a/drivers/i2c/busses/i2c-npcm7xx.c b/drivers/i2c/busses/i2c-npcm7xx.c new file mode 100644 index 000000000000..ce9699d56835 --- /dev/null +++ b/drivers/i2c/busses/i2c-npcm7xx.c @@ -0,0 +1,2485 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Nuvoton NPCM7xx SMB Controller driver + * + * Copyright (C) 2018 Nuvoton Technologies tali.perry@nuvoton.com + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define I2C_VERSION "0.1.0" + +enum smb_mode { + SMB_SLAVE = 1, + SMB_MASTER +}; + +/* + * External SMB Interface driver xfer indication values, which indicate status + * of the bus. + */ +enum smb_state_ind { + SMB_NO_STATUS_IND = 0, + SMB_SLAVE_RCV_IND = 1, + SMB_SLAVE_XMIT_IND = 2, + SMB_SLAVE_XMIT_MISSING_DATA_IND = 3, + SMB_SLAVE_RESTART_IND = 4, + SMB_SLAVE_DONE_IND = 5, + SMB_MASTER_DONE_IND = 6, + SMB_NACK_IND = 8, + SMB_BUS_ERR_IND = 9, + SMB_WAKE_UP_IND = 10, + SMB_BLOCK_BYTES_ERR_IND = 12, + SMB_SLAVE_RCV_MISSING_DATA_IND = 14, +}; + +// SMBus Operation type values +enum smb_oper { + SMB_NO_OPER = 0, + SMB_WRITE_OPER = 1, + SMB_READ_OPER = 2 +}; + +// SMBus Bank (FIFO mode) +enum smb_bank { + SMB_BANK_0 = 0, + SMB_BANK_1 = 1 +}; + +// Internal SMB states values (for the SMB module state machine). +enum smb_state { + SMB_DISABLE = 0, + SMB_IDLE, + SMB_MASTER_START, + SMB_SLAVE_MATCH, + SMB_OPER_STARTED, + SMB_STOP_PENDING +}; + +// Module supports setting multiple own slave addresses +enum smb_addr { + SMB_SLAVE_ADDR1 = 0, + SMB_SLAVE_ADDR2, + SMB_SLAVE_ADDR3, + SMB_SLAVE_ADDR4, + SMB_SLAVE_ADDR5, + SMB_SLAVE_ADDR6, + SMB_SLAVE_ADDR7, + SMB_SLAVE_ADDR8, + SMB_SLAVE_ADDR9, + SMB_SLAVE_ADDR10, + SMB_GC_ADDR, + SMB_ARP_ADDR +}; + +// global regs +static struct regmap *gcr_regmap; +static struct regmap *clk_regmap; + +#define NPCM_I2CSEGCTL 0xE4 +#define I2CSEGCTL_VAL 0x0333F000 + +// Common regs +#define NPCM_SMBSDA 0x000 +#define NPCM_SMBST 0x002 +#define NPCM_SMBCST 0x004 +#define NPCM_SMBCTL1 0x006 +#define NPCM_SMBADDR1 0x008 +#define NPCM_SMBCTL2 0x00A +#define NPCM_SMBADDR2 0x00C +#define NPCM_SMBCTL3 0x00E +#define NPCM_SMBCST2 0x018 +#define NPCM_SMBCST3 0x019 +#define SMB_VER 0x01F + +// BANK 0 regs +#define NPCM_SMBADDR3 0x010 +#define NPCM_SMBADDR7 0x011 +#define NPCM_SMBADDR4 0x012 +#define NPCM_SMBADDR8 0x013 +#define NPCM_SMBADDR5 0x014 +#define NPCM_SMBADDR9 0x015 +#define NPCM_SMBADDR6 0x016 +#define NPCM_SMBADDR10 0x017 + +// SMBADDR array: because the addr regs are sprinkled all over the address space +const int NPCM_SMBADDR[10] = {NPCM_SMBADDR1, NPCM_SMBADDR2, NPCM_SMBADDR3, + NPCM_SMBADDR4, NPCM_SMBADDR5, NPCM_SMBADDR6, + NPCM_SMBADDR7, NPCM_SMBADDR8, NPCM_SMBADDR9, + NPCM_SMBADDR10}; + +#define NPCM_SMBCTL4 0x01A +#define NPCM_SMBCTL5 0x01B +#define NPCM_SMBSCLLT 0x01C // SCL Low Time +#define NPCM_SMBFIF_CTL 0x01D // FIFO Control +#define NPCM_SMBSCLHT 0x01E // SCL High Time + +// BANK 1 regs +#define NPCM_SMBFIF_CTS 0x010 // Both FIFOs Control and status +#define NPCM_SMBTXF_CTL 0x012 // Tx-FIFO Control +#define NPCM_SMBT_OUT 0x014 // Bus T.O. +#define NPCM_SMBPEC 0x016 // PEC Data +#define NPCM_SMBTXF_STS 0x01A // Tx-FIFO Status +#define NPCM_SMBRXF_STS 0x01C // Rx-FIFO Status +#define NPCM_SMBRXF_CTL 0x01E // Rx-FIFO Control + +// NPCM_SMBST reg fields +#define NPCM_SMBST_XMIT BIT(0) +#define NPCM_SMBST_MASTER BIT(1) +#define NPCM_SMBST_NMATCH BIT(2) +#define NPCM_SMBST_STASTR BIT(3) +#define NPCM_SMBST_NEGACK BIT(4) +#define NPCM_SMBST_BER BIT(5) +#define NPCM_SMBST_SDAST BIT(6) +#define NPCM_SMBST_SLVSTP BIT(7) + +// NPCM_SMBCST reg fields +#define NPCM_SMBCST_BUSY BIT(0) +#define NPCM_SMBCST_BB BIT(1) +#define NPCM_SMBCST_MATCH BIT(2) +#define NPCM_SMBCST_GCMATCH BIT(3) +#define NPCM_SMBCST_TSDA BIT(4) +#define NPCM_SMBCST_TGSCL BIT(5) +#define NPCM_SMBCST_MATCHAF BIT(6) +#define NPCM_SMBCST_ARPMATCH BIT(7) + +// NPCM_SMBCTL1 reg fields +#define NPCM_SMBCTL1_START BIT(0) +#define NPCM_SMBCTL1_STOP BIT(1) +#define NPCM_SMBCTL1_INTEN BIT(2) +#define NPCM_SMBCTL1_EOBINTE BIT(3) +#define NPCM_SMBCTL1_ACK BIT(4) +#define NPCM_SMBCTL1_GCMEN BIT(5) +#define NPCM_SMBCTL1_NMINTE BIT(6) +#define NPCM_SMBCTL1_STASTRE BIT(7) + +// RW1S fields (inside a RW reg): +#define NPCM_SMBCTL1_RWS_FIELDS (NPCM_SMBCTL1_START | NPCM_SMBCTL1_STOP | \ + NPCM_SMBCTL1_ACK) +// NPCM_SMBADDR reg fields +#define NPCM_SMBADDR_A GENMASK(6, 0) +#define NPCM_SMBADDR_SAEN BIT(7) + +// NPCM_SMBCTL2 reg fields +#define SMBCTL2_ENABLE BIT(0) +#define SMBCTL2_SCLFRQ6_0 GENMASK(7, 1) + +// NPCM_SMBCTL3 reg fields +#define SMBCTL3_SCLFRQ8_7 GENMASK(1, 0) +#define SMBCTL3_ARPMEN BIT(2) +#define SMBCTL3_IDL_START BIT(3) +#define SMBCTL3_400K_MODE BIT(4) +#define SMBCTL3_BNK_SEL BIT(5) +#define SMBCTL3_SDA_LVL BIT(6) +#define SMBCTL3_SCL_LVL BIT(7) + +// NPCM_SMBCST2 reg fields +#define NPCM_SMBCST2_MATCHA1F BIT(0) +#define NPCM_SMBCST2_MATCHA2F BIT(1) +#define NPCM_SMBCST2_MATCHA3F BIT(2) +#define NPCM_SMBCST2_MATCHA4F BIT(3) +#define NPCM_SMBCST2_MATCHA5F BIT(4) +#define NPCM_SMBCST2_MATCHA6F BIT(5) +#define NPCM_SMBCST2_MATCHA7F BIT(5) +#define NPCM_SMBCST2_INTSTS BIT(7) + +// NPCM_SMBCST3 reg fields +#define NPCM_SMBCST3_MATCHA8F BIT(0) +#define NPCM_SMBCST3_MATCHA9F BIT(1) +#define NPCM_SMBCST3_MATCHA10F BIT(2) +#define NPCM_SMBCST3_EO_BUSY BIT(7) + +// NPCM_SMBCTL4 reg fields +#define SMBCTL4_HLDT GENMASK(5, 0) +#define SMBCTL4_LVL_WE BIT(7) + +// NPCM_SMBCTL5 reg fields +#define SMBCTL5_DBNCT GENMASK(3, 0) + +// NPCM_SMBFIF_CTS reg fields +#define NPCM_SMBFIF_CTS_RXF_TXE BIT(1) +#define NPCM_SMBFIF_CTS_RFTE_IE BIT(3) +#define NPCM_SMBFIF_CTS_CLR_FIFO BIT(6) +#define NPCM_SMBFIF_CTS_SLVRSTR BIT(7) + +// NPCM_SMBTXF_CTL reg fields +#define NPCM_SMBTXF_CTL_TX_THR GENMASK(4, 0) +#define NPCM_SMBTXF_CTL_THR_TXIE BIT(6) + +// NPCM_SMBT_OUT reg fields +#define NPCM_SMBT_OUT_TO_CKDIV GENMASK(5, 0) +#define NPCM_SMBT_OUT_T_OUTIE BIT(6) +#define NPCM_SMBT_OUT_T_OUTST BIT(7) + +// NPCM_SMBTXF_STS reg fields +#define NPCM_SMBTXF_STS_TX_BYTES GENMASK(4, 0) +#define NPCM_SMBTXF_STS_TX_THST BIT(6) + +// NPCM_SMBRXF_STS reg fields +#define NPCM_SMBRXF_STS_RX_BYTES GENMASK(4, 0) +#define NPCM_SMBRXF_STS_RX_THST BIT(6) + +// NPCM_SMBFIF_CTL reg fields +#define NPCM_SMBFIF_CTL_FIFO_EN BIT(4) + +// NPCM_SMBRXF_CTL reg fields +#define NPCM_SMBRXF_CTL_RX_THR GENMASK(4, 0) +#define NPCM_SMBRXF_CTL_LAST_PEC BIT(5) +#define NPCM_SMBRXF_CTL_THR_RXIE BIT(6) + +#define SMBUS_FIFO_SIZE 16 + +// SMB_VER reg fields +#define SMB_VER_VERSION GENMASK(6, 0) +#define SMB_VER_FIFO_EN BIT(7) + +// stall/stuck timeout +const unsigned int DEFAULT_STALL_COUNT = 25; + +// retries in a loop for master abort +const unsigned int RETRIES_NUM = 10000; + +// SMBus spec. values in KHZ +const unsigned int SMBUS_FREQ_MIN = 10; +const unsigned int SMBUS_FREQ_MAX = 1000; +const unsigned int SMBUS_FREQ_100KHZ = 100; +const unsigned int SMBUS_FREQ_400KHZ = 400; +const unsigned int SMBUS_FREQ_1MHZ = 1000; + +// SCLFRQ min/max field values +const unsigned int SCLFRQ_MIN = 10; +const unsigned int SCLFRQ_MAX = 511; + +// SCLFRQ field position +#define SCLFRQ_0_TO_6 GENMASK(6, 0) +#define SCLFRQ_7_TO_8 GENMASK(8, 7) + +const unsigned int SMB_NUM_OF_ADDR = 10; + +#define NPCM_I2C_EVENT_START BIT(0) +#define NPCM_I2C_EVENT_STOP BIT(1) +#define NPCM_I2C_EVENT_ABORT BIT(2) +#define NPCM_I2C_EVENT_WRITE BIT(3) + +#define NPCM_I2C_EVENT_READ BIT(4) +#define NPCM_I2C_EVENT_BER BIT(5) +#define NPCM_I2C_EVENT_NACK BIT(6) +#define NPCM_I2C_EVENT_TO BIT(7) + +#define NPCM_I2C_EVENT_EOB BIT(8) +#define NPCM_I2C_EVENT_STALL BIT(9) +#define NPCM_I2C_EVENT_CB BIT(10) +#define NPCM_I2C_EVENT_DONE BIT(11) + +#define NPCM_I2C_EVENT_READ1 BIT(12) +#define NPCM_I2C_EVENT_READ2 BIT(13) +#define NPCM_I2C_EVENT_READ3 BIT(14) +#define NPCM_I2C_EVENT_READ4 BIT(15) + +#define NPCM_I2C_EVENT_NMATCH_SLV BIT(16) +#define NPCM_I2C_EVENT_NMATCH_MSTR BIT(17) +#define NPCM_I2C_EVENT_BER_SLV BIT(18) + +#define NPCM_I2C_EVENT_LOG(event) (bus->event_log |= event) + +// Status of one SMBus module +struct npcm_i2c { + struct i2c_adapter adap; + struct device *dev; + unsigned char __iomem *reg; + spinlock_t lock; /* IRQ synchronization */ + struct completion cmd_complete; + int irq; + int cmd_err; + struct i2c_msg *msgs; + int msgs_num; + int num; + u32 apb_clk; + struct i2c_bus_recovery_info rinfo; + enum smb_state state; + enum smb_oper operation; + enum smb_mode master_or_slave; + enum smb_state_ind stop_ind; + u8 dest_addr; + u8 *rd_buf; + u16 rd_size; + u16 rd_ind; + u8 *wr_buf; + u16 wr_size; + u16 wr_ind; + bool fifo_use; + + // PEC bit mask per slave address. + // 1: use PEC for this address, + // 0: do not use PEC for this address + u16 PEC_mask; + bool PEC_use; + bool read_block_use; + u8 int_cnt; + u32 event_log; + u32 event_log_prev; + u32 clk_period_us; + unsigned long int_time_stamp; + unsigned long bus_freq; // in kHz + u32 xmits; + +#if IS_ENABLED(CONFIG_I2C_SLAVE) + u8 own_slave_addr; + struct i2c_client *slave; + + // currently I2C slave IF only supports single byte operations. + // in order to utilyze the npcm HW FIFO, the driver will ask for 16bytes + // at a time, pack them in buffer, and then transmit them all together + // to the FIFO and onward to the bus . + // NACK on read will be once reached to bus->adap->quirks->max_read_len + // sending a NACK whever the backend requests for it is not supported. + + // This module can be master and slave at the same time. separate ptrs + // and counters: + int slv_rd_size; + int slv_rd_ind; + int slv_wr_size; + int slv_wr_ind; + u8 slv_rd_buf[SMBUS_FIFO_SIZE]; + u8 slv_wr_buf[SMBUS_FIFO_SIZE]; +#endif +}; + +static inline void npcm_smb_select_bank(struct npcm_i2c *bus, + enum smb_bank bank) +{ + if (bank == SMB_BANK_0) + iowrite8(ioread8(bus->reg + NPCM_SMBCTL3) & ~SMBCTL3_BNK_SEL, + bus->reg + NPCM_SMBCTL3); + else + iowrite8(ioread8(bus->reg + NPCM_SMBCTL3) | SMBCTL3_BNK_SEL, + bus->reg + NPCM_SMBCTL3); +} + +static void npcm_smb_init_params(struct npcm_i2c *bus) +{ + bus->stop_ind = SMB_NO_STATUS_IND; + bus->rd_size = 0; + bus->wr_size = 0; + bus->rd_ind = 0; + bus->wr_ind = 0; + bus->int_cnt = 0; + bus->event_log_prev = bus->event_log; + bus->event_log = 0; + bus->read_block_use = false; + bus->int_time_stamp = 0; + bus->PEC_use = false; + bus->PEC_mask = 0; + if (bus->slave) + bus->master_or_slave = SMB_SLAVE; +} + +static inline void npcm_smb_wr_byte(struct npcm_i2c *bus, u8 data) +{ + iowrite8(data, bus->reg + NPCM_SMBSDA); +} + +static inline void npcm_smb_rd_byte(struct npcm_i2c *bus, u8 *data) +{ + *data = ioread8(bus->reg + NPCM_SMBSDA); +} + +static inline u16 npcm_smb_get_index(struct npcm_i2c *bus) +{ + u16 index = 0; + + if (bus->operation == SMB_READ_OPER) + index = bus->rd_ind; + else if (bus->operation == SMB_WRITE_OPER) + index = bus->wr_ind; + + return index; +} + +// quick protocol (just address): +static inline bool npcm_smb_is_quick(struct npcm_i2c *bus) +{ + if (bus->wr_size == 0 && bus->rd_size == 0) + return true; + return false; +} + +static void npcm_smb_disable(struct npcm_i2c *bus) +{ + int i; + + // select bank 0 for SMB addresses + npcm_smb_select_bank(bus, SMB_BANK_0); + + // Slave addresses removal + for (i = SMB_SLAVE_ADDR1; i < SMB_NUM_OF_ADDR; i++) + iowrite8(0, bus->reg + NPCM_SMBADDR[i]); + + npcm_smb_select_bank(bus, SMB_BANK_1); + + // Disable module. + iowrite8(ioread8(bus->reg + NPCM_SMBCTL2) & ~SMBCTL2_ENABLE, + bus->reg + NPCM_SMBCTL2); + + bus->state = SMB_DISABLE; +} + +static void npcm_smb_enable(struct npcm_i2c *bus) +{ + iowrite8((ioread8(bus->reg + NPCM_SMBCTL2) | SMBCTL2_ENABLE), + bus->reg + NPCM_SMBCTL2); + + bus->state = SMB_IDLE; +} + +static bool npcm_smb_wait_for_bus_free(struct npcm_i2c *bus, bool may_sleep) +{ + int cnt = 0; + int max_count = 2; /* wait for 2 ms */ + + if (may_sleep) + might_sleep(); + else + max_count = max_count * 100; /* since each delay is 10 us */ + + while (ioread8(bus->reg + NPCM_SMBCST) & NPCM_SMBCST_BUSY) { + if (cnt < max_count) { + if (may_sleep) + msleep_interruptible(1); + else + udelay(10); + cnt++; + + } else { + bus->cmd_err = -EAGAIN; + return false; + } + } + return true; +} + +// enable\disable end of busy (EOB) interrupt +static inline void npcm_smb_eob_int(struct npcm_i2c *bus, bool enable) +{ + // Clear EO_BUSY pending bit: + iowrite8(ioread8(bus->reg + NPCM_SMBCST3) | NPCM_SMBCST3_EO_BUSY, + bus->reg + NPCM_SMBCST3); + + if (enable) { + iowrite8((ioread8(bus->reg + NPCM_SMBCTL1) | + NPCM_SMBCTL1_EOBINTE) & ~NPCM_SMBCTL1_RWS_FIELDS, + bus->reg + NPCM_SMBCTL1); + } else { + iowrite8(ioread8(bus->reg + NPCM_SMBCTL1) & + ~NPCM_SMBCTL1_EOBINTE & ~NPCM_SMBCTL1_RWS_FIELDS, + bus->reg + NPCM_SMBCTL1); + } +} + +static inline bool npcm_smb_tx_fifo_empty(struct npcm_i2c *bus) +{ + u8 tx_fifo_sts = ioread8(bus->reg + NPCM_SMBTXF_STS); + + // check if TX FIFO is not empty + if ((tx_fifo_sts & NPCM_SMBTXF_STS_TX_BYTES) == 0) + return false; + + // check if TX FIFO status bit is set: + return (bool)FIELD_GET(NPCM_SMBTXF_STS_TX_THST, tx_fifo_sts); +} + +static inline bool npcm_smb_rx_fifo_full(struct npcm_i2c *bus) +{ + u8 rx_fifo_sts = ioread8(bus->reg + NPCM_SMBRXF_STS); + + // check if RX FIFO is not empty: + if ((rx_fifo_sts & NPCM_SMBRXF_STS_RX_BYTES) == 0) + return false; + + // check if rx fifo full status is set: + return (bool)FIELD_GET(NPCM_SMBRXF_STS_RX_THST, rx_fifo_sts); +} + +static inline void npcm_smb_clear_fifo_int(struct npcm_i2c *bus) +{ + iowrite8((ioread8(bus->reg + NPCM_SMBFIF_CTS) & + NPCM_SMBFIF_CTS_SLVRSTR) | + NPCM_SMBFIF_CTS_RXF_TXE, + bus->reg + NPCM_SMBFIF_CTS); +} + +static inline void npcm_smb_clear_tx_fifo(struct npcm_i2c *bus) +{ + iowrite8(ioread8(bus->reg + NPCM_SMBTXF_STS) | NPCM_SMBTXF_STS_TX_THST, + bus->reg + NPCM_SMBTXF_STS); +} + +static inline void npcm_smb_clear_rx_fifo(struct npcm_i2c *bus) +{ + iowrite8(ioread8(bus->reg + NPCM_SMBRXF_STS) | NPCM_SMBRXF_STS_RX_THST, + bus->reg + NPCM_SMBRXF_STS); +} + +static void npcm_smb_int_enable(struct npcm_i2c *bus, bool enable) +{ + if (enable) + iowrite8((ioread8(bus->reg + NPCM_SMBCTL1) | + NPCM_SMBCTL1_INTEN) & ~NPCM_SMBCTL1_RWS_FIELDS, + bus->reg + NPCM_SMBCTL1); + else + iowrite8((ioread8(bus->reg + NPCM_SMBCTL1) & + ~NPCM_SMBCTL1_INTEN) & ~NPCM_SMBCTL1_RWS_FIELDS, + bus->reg + NPCM_SMBCTL1); +} + +static inline void npcm_smb_master_start(struct npcm_i2c *bus) +{ + NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_START); + + iowrite8((ioread8(bus->reg + NPCM_SMBCTL1) | NPCM_SMBCTL1_START) & + ~(NPCM_SMBCTL1_STOP | NPCM_SMBCTL1_ACK), + bus->reg + NPCM_SMBCTL1); +} + +static inline void npcm_smb_master_stop(struct npcm_i2c *bus) +{ + NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_STOP); + + // override HW issue: SMBus may fail to supply stop condition in Master + // Write operation. + // Need to delay at least 5 us from the last int, before issueing a stop + udelay(10); + + iowrite8((ioread8(bus->reg + NPCM_SMBCTL1) | NPCM_SMBCTL1_STOP) & + ~(NPCM_SMBCTL1_START | NPCM_SMBCTL1_ACK), + bus->reg + NPCM_SMBCTL1); + + if (bus->fifo_use) { + npcm_smb_select_bank(bus, SMB_BANK_1); + + if (bus->operation == SMB_READ_OPER) + npcm_smb_clear_rx_fifo(bus); + else + npcm_smb_clear_tx_fifo(bus); + + npcm_smb_clear_fifo_int(bus); + + iowrite8(0, bus->reg + NPCM_SMBTXF_CTL); + } +} + +static inline void npcm_smb_stall_after_start(struct npcm_i2c *bus, bool stall) +{ + if (stall) + iowrite8((ioread8(bus->reg + NPCM_SMBCTL1) | + NPCM_SMBCTL1_STASTRE) & ~NPCM_SMBCTL1_RWS_FIELDS, + bus->reg + NPCM_SMBCTL1); + else + iowrite8((ioread8(bus->reg + NPCM_SMBCTL1) & + ~NPCM_SMBCTL1_STASTRE) & ~NPCM_SMBCTL1_RWS_FIELDS, + bus->reg + NPCM_SMBCTL1); +} + +static inline void npcm_smb_nack(struct npcm_i2c *bus) +{ + iowrite8((ioread8(bus->reg + NPCM_SMBCTL1) | NPCM_SMBCTL1_ACK) & + ~(NPCM_SMBCTL1_STOP | NPCM_SMBCTL1_START), + bus->reg + NPCM_SMBCTL1); +} + +static int npcm_smb_slave_enable_l(struct npcm_i2c *bus, + enum smb_addr addr_type, u8 addr, + bool enable); + +static void npcm_smb_reset(struct npcm_i2c *bus) +{ + // Save NPCM_SMBCTL1 relevant bits. It is being cleared when the + // module is disabled + u8 smbctl1; + + smbctl1 = ioread8(bus->reg + NPCM_SMBCTL1); + + // Disable the SMB module + iowrite8((ioread8(bus->reg + NPCM_SMBCTL2) & ~SMBCTL2_ENABLE), + bus->reg + NPCM_SMBCTL2); + + // Enable the SMB module + npcm_smb_enable(bus); + + // Restore NPCM_SMBCTL1 status + iowrite8(smbctl1 & ~NPCM_SMBCTL1_RWS_FIELDS, bus->reg + NPCM_SMBCTL1); + + // Clear BB (BUS BUSY) bit + iowrite8(NPCM_SMBCST_BB, bus->reg + NPCM_SMBCST); + + iowrite8(0xFF, bus->reg + NPCM_SMBST); + + // Clear EOB bit + iowrite8(NPCM_SMBCST3_EO_BUSY, bus->reg + NPCM_SMBCST3); + + // Clear all fifo bits: + iowrite8(NPCM_SMBFIF_CTS_CLR_FIFO, bus->reg + NPCM_SMBFIF_CTS); + +#if IS_ENABLED(CONFIG_I2C_SLAVE) + if (bus->slave) { + npcm_smb_slave_enable_l(bus, SMB_SLAVE_ADDR1, bus->slave->addr, + true); + } +#endif + + bus->state = SMB_IDLE; +} + +static inline bool npcm_smb_is_master(struct npcm_i2c *bus) +{ + return (bool)FIELD_GET(NPCM_SMBST_MASTER, + ioread8(bus->reg + NPCM_SMBST)); +} + +static void npcm_smb_callback(struct npcm_i2c *bus, + enum smb_state_ind op_status, u16 info) +{ + struct i2c_msg *msgs = bus->msgs; + int msgs_num = bus->msgs_num; + + NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_CB); + + if (!msgs) + return; + + if (completion_done(&bus->cmd_complete) == true) + return; + + switch (op_status) { + case SMB_MASTER_DONE_IND: + bus->cmd_err = bus->msgs_num; + // fall through: + case SMB_BLOCK_BYTES_ERR_IND: + // Master transaction finished and all transmit bytes were sent + if (bus->msgs) { + if (msgs[0].flags & I2C_M_RD) + msgs[0].len = info; + else if (msgs_num == 2 && + msgs[1].flags & I2C_M_RD) + msgs[1].len = info; + } + + NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_DONE); + + if (completion_done(&bus->cmd_complete) == false) + complete(&bus->cmd_complete); + break; + + case SMB_NACK_IND: + // MASTER transmit got a NACK before tx all bytes + // info: number of transmitted bytes + bus->cmd_err = -ENXIO; + if (bus->master_or_slave == SMB_MASTER) + complete(&bus->cmd_complete); + + break; + case SMB_BUS_ERR_IND: + // Bus error + bus->cmd_err = -EAGAIN; + if (bus->master_or_slave == SMB_MASTER) + complete(&bus->cmd_complete); + + break; + case SMB_WAKE_UP_IND: + // SMBus wake up + break; + default: + break; + } + + bus->operation = SMB_NO_OPER; + if (bus->slave) + bus->master_or_slave = SMB_SLAVE; +} + +static u32 npcm_smb_get_fifo_fullness(struct npcm_i2c *bus) +{ + if (bus->operation == SMB_WRITE_OPER) + return FIELD_GET(NPCM_SMBTXF_STS_TX_BYTES, + ioread8(bus->reg + NPCM_SMBTXF_STS)); + else if (bus->operation == SMB_READ_OPER) + return FIELD_GET(NPCM_SMBRXF_STS_RX_BYTES, + ioread8(bus->reg + NPCM_SMBRXF_STS)); + return 0; +} + +static void npcm_smb_write_to_fifo_master(struct npcm_i2c *bus, + u16 max_bytes_to_send) +{ + // Fill the FIFO, while the FIFO is not full and there are more bytes to + // write + if (max_bytes_to_send == 0) + return; + while ((max_bytes_to_send--) && (SMBUS_FIFO_SIZE - + npcm_smb_get_fifo_fullness(bus))) { + if (bus->wr_ind < bus->wr_size) + npcm_smb_wr_byte(bus, bus->wr_buf[bus->wr_ind++]); + else + npcm_smb_wr_byte(bus, 0xFF); + } +} + +#if IS_ENABLED(CONFIG_I2C_SLAVE) +static void npcm_smb_write_to_fifo_slave(struct npcm_i2c *bus, + u16 max_bytes_to_send) +{ + // Fill the FIFO, while the FIFO is not full and there are more bytes to + // write + npcm_smb_clear_fifo_int(bus); + npcm_smb_clear_tx_fifo(bus); + iowrite8(0, bus->reg + NPCM_SMBTXF_CTL); + + if (max_bytes_to_send == 0) + return; + + while ((max_bytes_to_send--) && (SMBUS_FIFO_SIZE - + npcm_smb_get_fifo_fullness(bus))) { + if (bus->slv_wr_size > 0) { + npcm_smb_wr_byte(bus, + bus->slv_wr_buf[bus->slv_wr_ind % + SMBUS_FIFO_SIZE]); + bus->slv_wr_ind = (bus->slv_wr_ind + 1) % + SMBUS_FIFO_SIZE; + bus->slv_wr_size--; // size indicates the # of bytes in + // the SW FIFO, not HW. + } else { + break; + } + } +} +#endif + +// configure the FIFO before using it. If nread is -1 RX FIFO will not be +// configured. same for nwrite +static void npcm_smb_set_fifo(struct npcm_i2c *bus, int nread, int nwrite) +{ + u8 rxf_ctl = 0; + + if (!bus->fifo_use) + return; + npcm_smb_select_bank(bus, SMB_BANK_1); + npcm_smb_clear_tx_fifo(bus); + npcm_smb_clear_rx_fifo(bus); + + // configure RX FIFO + if (nread > 0) { + rxf_ctl = min_t(u16, (u16)nread, (u16)SMBUS_FIFO_SIZE); + + // set LAST bit. if LAST is set enxt FIFO packet is nacked + // regular read of less then buffer size: + if (nread <= SMBUS_FIFO_SIZE) + rxf_ctl |= NPCM_SMBRXF_CTL_LAST_PEC; + // if we are about to read the first byte in blk rd mode, + // don't NACK it. BTW, if slave return zero size HW can't NACK + // it immidiattly, it will read extra byte and then NACK. + if (bus->rd_ind == 0 && bus->read_block_use) { + // set fifo to read one byte, no last: + rxf_ctl = 1; + } + + // set fifo size: + iowrite8(rxf_ctl, bus->reg + NPCM_SMBRXF_CTL); + } + + // configure TX FIFO + if (nwrite > 0) { + if (nwrite > SMBUS_FIFO_SIZE) + // data to send is more then FIFO size. + // Configure the FIFO int to be after of FIFO is cleared + iowrite8(SMBUS_FIFO_SIZE, bus->reg + NPCM_SMBTXF_CTL); + else + iowrite8(nwrite, bus->reg + NPCM_SMBTXF_CTL); + + npcm_smb_clear_tx_fifo(bus); + } +} + +static void npcm_smb_read_from_fifo(struct npcm_i2c *bus, u8 bytes_in_fifo) +{ + u8 data; + + while (bytes_in_fifo--) { + npcm_smb_rd_byte(bus, &data); + + if (bus->master_or_slave == SMB_MASTER) { + if (bus->rd_ind < bus->rd_size) + bus->rd_buf[bus->rd_ind++] = data; + } else { // SMB_SLAVE: +#if IS_ENABLED(CONFIG_I2C_SLAVE) + if (bus->slave) { + bus->slv_rd_buf[bus->slv_rd_ind % + SMBUS_FIFO_SIZE] = data; + bus->slv_rd_ind++; + if (bus->slv_rd_ind == 1 && bus->read_block_use) + // 1st byte is length in block protocol + bus->slv_rd_size = data + + (u8)bus->PEC_use + + (u8)bus->read_block_use; + } +#endif + } + } +} + +static int npcm_smb_master_abort(struct npcm_i2c *bus) +{ + int ret = 0; + + NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_ABORT); + + // Only current master is allowed to issue Stop Condition + if (npcm_smb_is_master(bus)) { + npcm_smb_eob_int(bus, true); + npcm_smb_master_stop(bus); + + // Clear NEGACK, STASTR and BER bits + iowrite8(NPCM_SMBST_BER | NPCM_SMBST_NEGACK | NPCM_SMBST_STASTR, + bus->reg + NPCM_SMBST); + } + + return ret; +} + +#if IS_ENABLED(CONFIG_I2C_SLAVE) +static irqreturn_t npcm_i2c_bus_irq(int irq, void *dev_id); + +static int npcm_smb_slave_enable_l(struct npcm_i2c *bus, + enum smb_addr addr_type, u8 addr, + bool enable) +{ + u8 slave_addr_reg = FIELD_PREP(NPCM_SMBADDR_A, addr) | + FIELD_PREP(NPCM_SMBADDR_SAEN, enable); + + if (addr_type == SMB_GC_ADDR) { + iowrite8((ioread8(bus->reg + NPCM_SMBCTL1) & + ~NPCM_SMBCTL1_GCMEN) | + FIELD_PREP(NPCM_SMBCTL1_GCMEN, enable), + bus->reg + NPCM_SMBCTL1); + return 0; + } + if (addr_type == SMB_ARP_ADDR) { + iowrite8((ioread8(bus->reg + NPCM_SMBCTL3) & + ~SMBCTL3_ARPMEN) | + FIELD_PREP(SMBCTL3_ARPMEN, enable), + bus->reg + NPCM_SMBCTL3); + return 0; + } + if (addr_type >= SMB_ARP_ADDR) + return -EFAULT; + + // select bank 0 for address 3 to 10 + if (addr_type > SMB_SLAVE_ADDR2) + npcm_smb_select_bank(bus, SMB_BANK_0); + + // Set and enable the address + iowrite8(slave_addr_reg, bus->reg + NPCM_SMBADDR[(int)addr_type]); + + // enable interrupt on slave match: + iowrite8((ioread8(bus->reg + NPCM_SMBCTL1) | NPCM_SMBCTL1_NMINTE) & + ~NPCM_SMBCTL1_RWS_FIELDS, bus->reg + NPCM_SMBCTL1); + + if (addr_type > SMB_SLAVE_ADDR2) + npcm_smb_select_bank(bus, SMB_BANK_1); + return 0; +} + +static u8 npcm_smb_get_slave_addr(struct npcm_i2c *bus, + enum smb_addr addr_type) +{ + u8 slave_add; + + // select bank 0 for address 3 to 10 + if (addr_type > SMB_SLAVE_ADDR2) + npcm_smb_select_bank(bus, SMB_BANK_0); + + slave_add = ioread8(bus->reg + NPCM_SMBADDR[(int)addr_type]); + + if (addr_type > SMB_SLAVE_ADDR2) + npcm_smb_select_bank(bus, SMB_BANK_1); + + return slave_add; +} + +static int npcm_smb_remove_slave_addr(struct npcm_i2c *bus, u8 slave_add) +{ + int i; + + slave_add |= 0x80; //Set the enable bit + + npcm_smb_select_bank(bus, SMB_BANK_0); + + for (i = SMB_SLAVE_ADDR1; i < SMB_NUM_OF_ADDR; i++) { + if (ioread8(bus->reg + NPCM_SMBADDR[i]) == slave_add) + iowrite8(0, bus->reg + NPCM_SMBADDR[i]); + } + + npcm_smb_select_bank(bus, SMB_BANK_1); + + return 0; +} + +static int npcm_i2c_slave_get_wr_buf(struct npcm_i2c *bus) +{ + u8 value = 0; + int ret = bus->slv_wr_ind; + int i; + + // fill a cyclic buffer + for (i = 0; i < SMBUS_FIFO_SIZE; i++) { + if (bus->slv_wr_size >= SMBUS_FIFO_SIZE) + break; + i2c_slave_event(bus->slave, I2C_SLAVE_READ_REQUESTED, &value); + bus->slv_wr_buf[(bus->slv_wr_ind + bus->slv_wr_size) % + SMBUS_FIFO_SIZE] = value; + bus->slv_wr_size++; + i2c_slave_event(bus->slave, I2C_SLAVE_READ_PROCESSED, &value); + } + return SMBUS_FIFO_SIZE - ret; +} + +static void npcm_i2c_slave_send_rd_buf(struct npcm_i2c *bus) +{ + int i; + + for (i = 0; i < bus->slv_rd_ind; i++) + i2c_slave_event(bus->slave, I2C_SLAVE_WRITE_RECEIVED, + &bus->slv_rd_buf[i]); + + // once we send bytes up, need to reset the counter of the wr buf + // got data from master (new offset in device), ignore wr fifo: + if (bus->slv_rd_ind) { + bus->slv_wr_size = 0; + bus->slv_wr_ind = 0; + } + + bus->slv_rd_ind = 0; + bus->slv_rd_size = bus->adap.quirks->max_read_len; + + npcm_smb_clear_fifo_int(bus); + npcm_smb_clear_rx_fifo(bus); +} + +static bool npcm_smb_slave_receive(struct npcm_i2c *bus, u16 nread, + u8 *read_data) +{ + bus->state = SMB_OPER_STARTED; + bus->operation = SMB_READ_OPER; + bus->slv_rd_size = nread; + bus->slv_rd_ind = 0; + + iowrite8(0, bus->reg + NPCM_SMBTXF_CTL); + iowrite8(SMBUS_FIFO_SIZE, bus->reg + NPCM_SMBRXF_CTL); + + npcm_smb_clear_tx_fifo(bus); + npcm_smb_clear_rx_fifo(bus); + + return true; +} + +static bool npcm_smb_slave_xmit(struct npcm_i2c *bus, u16 nwrite, + u8 *write_data) +{ + if (nwrite == 0) + return false; + + bus->state = SMB_OPER_STARTED; + bus->operation = SMB_WRITE_OPER; + + // get the next buffer + npcm_i2c_slave_get_wr_buf(bus); + + if (nwrite > 0) + npcm_smb_write_to_fifo_slave(bus, nwrite); + + return true; +} + +// currently slave IF only supports single byte operations. +// in order to utilyze the npcm HW FIFO, the driver will ask for 16 bytes +// at a time, pack them in buffer, and then transmit them all together +// to the FIFO and onward to the bus. +// NACK on read will be once reached to bus->adap->quirks->max_read_len. +// sending a NACK wherever the backend requests for it is not supported. +// the next two functions allow reading to local buffer before writing it all +// to the HW FIFO. +// ret val: number of bytes read form the IF: + +static int npcm_i2c_slave_wr_buf_sync(struct npcm_i2c *bus) +{ + int left_in_fifo = FIELD_GET(NPCM_SMBTXF_STS_TX_BYTES, + ioread8(bus->reg + NPCM_SMBTXF_STS)); + + if (left_in_fifo >= SMBUS_FIFO_SIZE) + return left_in_fifo; + + if (bus->slv_wr_size >= SMBUS_FIFO_SIZE) + return left_in_fifo; // fifo already full + + // update the wr fifo ind, back to the untransmitted bytes: + bus->slv_wr_ind = bus->slv_wr_ind - left_in_fifo; + bus->slv_wr_size = bus->slv_wr_size + left_in_fifo; + + if (bus->slv_wr_ind < 0) + bus->slv_wr_ind += SMBUS_FIFO_SIZE; + + return left_in_fifo; +} + +static void npcm_i2c_slave_rd_wr(struct npcm_i2c *bus) +{ + if (FIELD_GET(NPCM_SMBST_XMIT, ioread8(bus->reg + NPCM_SMBST))) { + // Slave got an address match with direction bit 1 so + // it should transmit data + // Write till the master will NACK + bus->operation = SMB_WRITE_OPER; + npcm_smb_slave_xmit(bus, + bus->adap.quirks->max_write_len, + bus->slv_wr_buf); + } else { + // Slave got an address match with direction bit 0 + // so it should receive data. + // this module does not support saying no to bytes. + // it will always ACK. + bus->operation = SMB_READ_OPER; + npcm_smb_read_from_fifo(bus, npcm_smb_get_fifo_fullness(bus)); + bus->stop_ind = SMB_SLAVE_RCV_IND; + npcm_i2c_slave_send_rd_buf(bus); + npcm_smb_slave_receive(bus, + bus->adap.quirks->max_read_len, + bus->slv_rd_buf); + } +} + +static irqreturn_t npcm_smb_int_slave_handler(struct npcm_i2c *bus) +{ + irqreturn_t ret = IRQ_NONE; + u8 smbst = ioread8(bus->reg + NPCM_SMBST); + // Slave: A NACK has occurred + if (FIELD_GET(NPCM_SMBST_NEGACK, smbst)) { + NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_NACK); + bus->stop_ind = SMB_NACK_IND; + npcm_i2c_slave_wr_buf_sync(bus); + if (bus->fifo_use) + // clear the FIFO + iowrite8(NPCM_SMBFIF_CTS_CLR_FIFO, + bus->reg + NPCM_SMBFIF_CTS); + + // In slave write, NACK is OK, otherwise it is a problem + bus->stop_ind = SMB_NO_STATUS_IND; + bus->operation = SMB_NO_OPER; + bus->own_slave_addr = 0xFF; + + // Slave has to wait for SMB_STOP to decide this is the end + // of the transaction. + // Therefore transaction is not yet considered as done + iowrite8(NPCM_SMBST_NEGACK, bus->reg + NPCM_SMBST); + + ret = IRQ_HANDLED; + } + + // Slave mode: a Bus Error (BER) has been identified + if (FIELD_GET(NPCM_SMBST_BER, smbst)) { + // Check whether bus arbitration or Start or Stop during data + // xfer bus arbitration problem should not result in recovery + NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_BER_SLV); + bus->stop_ind = SMB_BUS_ERR_IND; + + // wait for bus busy before clear fifo + iowrite8(NPCM_SMBFIF_CTS_CLR_FIFO, bus->reg + NPCM_SMBFIF_CTS); + + bus->state = SMB_IDLE; + + // in BER case we might get 2 interrupts: one for slave one for + // master ( for a channel which is master\slave switching) + if (completion_done(&bus->cmd_complete) == false) { + bus->cmd_err = -EIO; + complete(&bus->cmd_complete); + } + bus->own_slave_addr = 0xFF; + iowrite8(NPCM_SMBST_BER, bus->reg + NPCM_SMBST); + ret = IRQ_HANDLED; + } + + // A Slave Stop Condition has been identified + if (FIELD_GET(NPCM_SMBST_SLVSTP, smbst)) { + int bytes_in_fifo = npcm_smb_get_fifo_fullness(bus); + + bus->stop_ind = SMB_SLAVE_DONE_IND; + + if (bus->operation == SMB_READ_OPER) { + npcm_smb_read_from_fifo(bus, bytes_in_fifo); + + // Slave done transmitting or receiving + // if the buffer is empty nothing will be sent + } + + // Slave done transmitting or receiving + // if the buffer is empty nothing will be sent + npcm_i2c_slave_send_rd_buf(bus); + + bus->stop_ind = SMB_NO_STATUS_IND; + + // Note, just because we got here, it doesn't mean we through + // away the wr buffer. + // we keep it until the next received offset. + bus->operation = SMB_NO_OPER; + bus->int_cnt = 0; + bus->event_log_prev = bus->event_log; + bus->event_log = 0; + bus->own_slave_addr = 0xFF; + + i2c_slave_event(bus->slave, I2C_SLAVE_STOP, 0); + + iowrite8(NPCM_SMBST_SLVSTP, bus->reg + NPCM_SMBST); + + if (bus->fifo_use) { + npcm_smb_clear_fifo_int(bus); + npcm_smb_clear_rx_fifo(bus); + npcm_smb_clear_tx_fifo(bus); + + iowrite8(NPCM_SMBFIF_CTS_CLR_FIFO, + bus->reg + NPCM_SMBFIF_CTS); + } + + bus->state = SMB_IDLE; + ret = IRQ_HANDLED; + } + + // restart condition occurred and Rx-FIFO was not empty + if (bus->fifo_use && FIELD_GET(NPCM_SMBFIF_CTS_SLVRSTR, + ioread8(bus->reg + NPCM_SMBFIF_CTS))) { + bus->stop_ind = SMB_SLAVE_RESTART_IND; + + bus->master_or_slave = SMB_SLAVE; + + if (bus->operation == SMB_READ_OPER) + npcm_smb_read_from_fifo(bus, + npcm_smb_get_fifo_fullness(bus) + ); + + bus->operation = SMB_WRITE_OPER; + + iowrite8(0, bus->reg + NPCM_SMBRXF_CTL); + + iowrite8(NPCM_SMBFIF_CTS_CLR_FIFO | NPCM_SMBFIF_CTS_SLVRSTR | + NPCM_SMBFIF_CTS_RXF_TXE, bus->reg + NPCM_SMBFIF_CTS); + + npcm_i2c_slave_rd_wr(bus); + + ret = IRQ_HANDLED; + } + + // A Slave Address Match has been identified + if (FIELD_GET(NPCM_SMBST_NMATCH, smbst)) { + u8 info = 0; + + NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_NMATCH_SLV); + // Address match automatically implies slave mode + bus->master_or_slave = SMB_SLAVE; + + npcm_smb_clear_fifo_int(bus); + npcm_smb_clear_rx_fifo(bus); + npcm_smb_clear_tx_fifo(bus); + iowrite8(0, bus->reg + NPCM_SMBTXF_CTL); + iowrite8(SMBUS_FIFO_SIZE, bus->reg + NPCM_SMBRXF_CTL); + + if (FIELD_GET(NPCM_SMBST_XMIT, smbst)) { + bus->operation = SMB_WRITE_OPER; + } else { + i2c_slave_event(bus->slave, I2C_SLAVE_WRITE_REQUESTED, + &info); + bus->operation = SMB_READ_OPER; + } + + if (bus->own_slave_addr == 0xFF) { // unknown address + // Check which type of address match + if (FIELD_GET(NPCM_SMBCST_MATCH, + ioread8(bus->reg + NPCM_SMBCST))) { + u16 addr; + enum smb_addr eaddr; + + addr = ((ioread8(bus->reg + NPCM_SMBCST3) & + 0x7) << 7) | + (ioread8(bus->reg + NPCM_SMBCST2) & + 0x7F); + + info = ffs(addr); + eaddr = (enum smb_addr)info; + + addr = FIELD_GET(NPCM_SMBADDR_A, + npcm_smb_get_slave_addr(bus, + eaddr) + ); + bus->own_slave_addr = addr; + + if (bus->PEC_mask & BIT(info)) + bus->PEC_use = true; + else + bus->PEC_use = false; + } else { + if (FIELD_GET(NPCM_SMBCST_GCMATCH, + ioread8(bus->reg + NPCM_SMBCST))) + bus->own_slave_addr = 0; + if (FIELD_GET(NPCM_SMBCST_ARPMATCH, + ioread8(bus->reg + NPCM_SMBCST))) + bus->own_slave_addr = 0x61; + } + } else { + // Slave match can happen in two options: + // 1. Start, SA, read (slave read without further ado) + // 2. Start, SA, read, data, restart, SA, read, ... + // (slave read in fragmented mode) + // 3. Start, SA, write, data, restart, SA, read, .. + // (regular write-read mode) + if ((bus->state == SMB_OPER_STARTED && + bus->operation == SMB_READ_OPER && + bus->stop_ind == SMB_SLAVE_XMIT_IND) || + bus->stop_ind == SMB_SLAVE_RCV_IND) { + // slave transmit after slave receive w/o Slave + // Stop implies repeated start + bus->stop_ind = SMB_SLAVE_RESTART_IND; + } + } + + if (FIELD_GET(NPCM_SMBST_XMIT, smbst)) + bus->stop_ind = SMB_SLAVE_XMIT_IND; + else + bus->stop_ind = SMB_SLAVE_RCV_IND; + + bus->state = SMB_SLAVE_MATCH; + + npcm_i2c_slave_rd_wr(bus); + + iowrite8(NPCM_SMBST_NMATCH, bus->reg + NPCM_SMBST); + ret = IRQ_HANDLED; + } + + // Slave SDA status is set - transmit or receive, slave + if (FIELD_GET(NPCM_SMBST_SDAST, smbst) || + (bus->fifo_use && + (npcm_smb_tx_fifo_empty(bus) || npcm_smb_rx_fifo_full(bus)))) { + npcm_i2c_slave_rd_wr(bus); + + iowrite8(NPCM_SMBST_SDAST, bus->reg + NPCM_SMBST); + + ret = IRQ_HANDLED; + } //SDAST + + return ret; +} + +static int npcm_i2c_reg_slave(struct i2c_client *client) +{ + unsigned long lock_flags; + struct npcm_i2c *bus = i2c_get_adapdata(client->adapter); + + bus->slave = client; + + if (!bus->slave) + return -EINVAL; + + if (client->flags & I2C_CLIENT_TEN) + return -EAFNOSUPPORT; + + spin_lock_irqsave(&bus->lock, lock_flags); + + npcm_smb_init_params(bus); + bus->slv_rd_size = 0; + bus->slv_wr_size = 0; + bus->slv_rd_ind = 0; + bus->slv_wr_ind = 0; + if (client->flags & I2C_CLIENT_PEC) + bus->PEC_use = true; + + dev_info(bus->dev, "I2C%d register slave SA=0x%x, PEC=%d\n", bus->num, + client->addr, bus->PEC_use); + + npcm_smb_slave_enable_l(bus, SMB_SLAVE_ADDR1, client->addr, true); + + npcm_smb_clear_fifo_int(bus); + npcm_smb_clear_rx_fifo(bus); + npcm_smb_clear_tx_fifo(bus); + + spin_unlock_irqrestore(&bus->lock, lock_flags); + + return 0; +} + +static int npcm_i2c_unreg_slave(struct i2c_client *client) +{ + struct npcm_i2c *bus = client->adapter->algo_data; + unsigned long lock_flags; + + spin_lock_irqsave(&bus->lock, lock_flags); + if (!bus->slave) { + spin_unlock_irqrestore(&bus->lock, lock_flags); + return -EINVAL; + } + + npcm_smb_remove_slave_addr(bus, client->addr); + + bus->slave = NULL; + spin_unlock_irqrestore(&bus->lock, lock_flags); + + return 0; +} +#endif // CONFIG_I2C_SLAVE + +static void npcm_smb_master_fifo_read(struct npcm_i2c *bus) +{ + int rcount; + int fifo_bytes; + enum smb_state_ind ind = SMB_MASTER_DONE_IND; + + fifo_bytes = npcm_smb_get_fifo_fullness(bus); + + rcount = bus->rd_size - bus->rd_ind; + + // In order not to change the RX_TRH during transaction (we found that + // this might be problematic if it takes too much time to read the FIFO) + // we read the data in the following way. If the number of bytes to + // read == FIFO Size + C (where C < FIFO Size)then first read C bytes + // and in the next int we read rest of the data. + if (rcount < (2 * SMBUS_FIFO_SIZE) && rcount > SMBUS_FIFO_SIZE) + fifo_bytes = (u8)(rcount - SMBUS_FIFO_SIZE); + + if ((rcount - fifo_bytes) <= 0) { + // last bytes are about to be read - end of transaction. + // Stop should be set before reading last byte. + NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_READ4); + + bus->state = SMB_STOP_PENDING; + bus->stop_ind = ind; + + npcm_smb_eob_int(bus, true); + npcm_smb_master_stop(bus); + npcm_smb_read_from_fifo(bus, fifo_bytes); + } else { + NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_READ3); + npcm_smb_read_from_fifo(bus, fifo_bytes); + rcount = bus->rd_size - bus->rd_ind; + npcm_smb_set_fifo(bus, rcount, -1); + } +} + +static void npcm_smb_int_master_handler_write(struct npcm_i2c *bus) +{ + u16 wcount; + + NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_WRITE); + if (bus->fifo_use) + npcm_smb_clear_tx_fifo(bus); // clear the TX fifo status bit + + // Master write operation - last byte handling + if (bus->wr_ind == bus->wr_size) { + if (bus->fifo_use && npcm_smb_get_fifo_fullness(bus) > 0) + // No more bytes to send (to add to the FIFO), + // however the FIFO is not empty yet. It is + // still in the middle of tx. Currently there's nothing + // to do except for waiting to the end of the tx. + // We will get an int when the FIFO will get empty. + return; + + if (bus->rd_size == 0) { + // all bytes have been written, in a pure wr operation + npcm_smb_eob_int(bus, true); + + bus->state = SMB_STOP_PENDING; + bus->stop_ind = SMB_MASTER_DONE_IND; + + npcm_smb_master_stop(bus); + // Clear SDA Status bit (by writing dummy byte) + npcm_smb_wr_byte(bus, 0xFF); + + } else { + // last write-byte written on previous int - need to + // restart & send slave address + npcm_smb_set_fifo(bus, bus->rd_size, -1); + + // Generate repeated start upon next write to SDA + npcm_smb_master_start(bus); + + if (bus->rd_size == 1) + // Receiving one byte only - stall after + // successful completion of send + // address byte. If we NACK here, + // and slave doesn't ACK the address, we + // might unintentionally NACK the next + // multi-byte read + npcm_smb_stall_after_start(bus, true); + + // Next int will occur on read + bus->operation = SMB_READ_OPER; + + // send the slave address in read direction + npcm_smb_wr_byte(bus, bus->dest_addr | 0x1); + } + } else { + // write next byte not last byte and not slave address + if (!bus->fifo_use || bus->wr_size == 1) { + npcm_smb_wr_byte(bus, bus->wr_buf[bus->wr_ind++]); + } else { + wcount = bus->wr_size - bus->wr_ind; + npcm_smb_set_fifo(bus, -1, wcount); + npcm_smb_write_to_fifo_master(bus, wcount); + } + } +} + +static void npcm_smb_int_master_handler_read(struct npcm_i2c *bus) +{ + u16 block_extra_bytes_size; + u8 data; + + // Master read operation (pure read or following a write operation). + NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_READ); + + // added bytes to the packet: + block_extra_bytes_size = (u8)bus->read_block_use + (u8)bus->PEC_use; + + // Perform master read, distinguishing between last byte and the rest of + // the bytes. The last byte should be read when the clock is stopped + if (bus->rd_ind == 0) { //first byte handling: + // in block protocol first byte is the size + NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_READ1); + if (bus->read_block_use) { + // first byte in block protocol is the size: + npcm_smb_rd_byte(bus, &data); + + // if slave returned illegal size. read up to 32 bytes. + if (data >= I2C_SMBUS_BLOCK_MAX) + data = I2C_SMBUS_BLOCK_MAX; + + // is data is 0 -> not supported. read at least one byte + if (data == 0) + data = 1; + + bus->rd_size = data + block_extra_bytes_size; + + bus->rd_buf[bus->rd_ind++] = data; + + // clear RX FIFO interrupt status: + if (bus->fifo_use) { + iowrite8(NPCM_SMBFIF_CTS_RXF_TXE | + ioread8(bus->reg + NPCM_SMBFIF_CTS), + bus->reg + NPCM_SMBFIF_CTS); + } + + npcm_smb_set_fifo(bus, (bus->rd_size - 1), -1); + npcm_smb_stall_after_start(bus, false); + } else { + npcm_smb_clear_tx_fifo(bus); + npcm_smb_master_fifo_read(bus); + } + } else { + if (bus->rd_size == block_extra_bytes_size && + bus->read_block_use) { + bus->state = SMB_STOP_PENDING; + bus->stop_ind = SMB_BLOCK_BYTES_ERR_IND; + bus->cmd_err = -EIO; + npcm_smb_eob_int(bus, true); + npcm_smb_master_stop(bus); + npcm_smb_read_from_fifo(bus, + npcm_smb_get_fifo_fullness(bus) + ); + } else { + NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_READ2); + npcm_smb_master_fifo_read(bus); + } + } +} + +static irqreturn_t npcm_smb_int_master_handler(struct npcm_i2c *bus) +{ + irqreturn_t ret = IRQ_NONE; + u8 fif_cts; + + if (FIELD_GET(NPCM_SMBST_NMATCH, ioread8(bus->reg + NPCM_SMBST))) { + NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_NMATCH_MSTR); + iowrite8(NPCM_SMBST_NMATCH, bus->reg + NPCM_SMBST); + npcm_smb_nack(bus); + bus->stop_ind = SMB_BUS_ERR_IND; + npcm_smb_callback(bus, bus->stop_ind, npcm_smb_get_index(bus)); + + return IRQ_HANDLED; + } + // A NACK has occurred + if (FIELD_GET(NPCM_SMBST_NEGACK, ioread8(bus->reg + NPCM_SMBST))) { + NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_NACK); + if (bus->fifo_use) { + // if there are still untransmitted bytes in TX FIFO + // reduce them from wr_ind + if (bus->operation == SMB_WRITE_OPER) + bus->wr_ind -= npcm_smb_get_fifo_fullness(bus); + + // clear the FIFO + iowrite8(NPCM_SMBFIF_CTS_CLR_FIFO, + bus->reg + NPCM_SMBFIF_CTS); + } + + // In master write operation, NACK is a problem + // number of bytes sent to master less than required + bus->stop_ind = SMB_NACK_IND; + // Only current master is allowed to issue Stop Condition + if (npcm_smb_is_master(bus)) { + // stopping in the middle, not waiting for ints anymore + npcm_smb_eob_int(bus, false); + + npcm_smb_master_stop(bus); + + // Clear NEGACK, STASTR and BER bits + // In Master mode, NEGACK should be cleared only after + // generating STOP. + // In such case, the bus is released from stall only + // after the software clears NEGACK bit. + // Then a Stop condition is sent. + iowrite8(NPCM_SMBST_BER | NPCM_SMBST_NEGACK | + NPCM_SMBST_STASTR, bus->reg + NPCM_SMBST); + + npcm_smb_wait_for_bus_free(bus, false); + } + bus->state = SMB_IDLE; + + // In Master mode, NACK should be cleared only after + // generating STOP. + // In such case, the bus is released from stall only after the + // software clears NACK bit. + // Then a Stop condition is sent. + npcm_smb_callback(bus, bus->stop_ind, bus->wr_ind); + return IRQ_HANDLED; + } + + // Master mode: a Bus Error has been identified + if (FIELD_GET(NPCM_SMBST_BER, ioread8(bus->reg + NPCM_SMBST))) { + // Check whether bus arbitration or Start or Stop during data + // xfer bus arbitration problem should not result in recovery + NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_BER); + bus->stop_ind = SMB_BUS_ERR_IND; + if (npcm_smb_is_master(bus)) { + npcm_smb_master_abort(bus); + } else { + // Clear NEGACK, STASTR and BER bits + iowrite8(NPCM_SMBST_BER | NPCM_SMBST_NEGACK | + NPCM_SMBST_STASTR, bus->reg + NPCM_SMBST); + + // Clear BB (BUS BUSY) bit + iowrite8(NPCM_SMBCST_BB, bus->reg + NPCM_SMBCST); + + bus->cmd_err = -EAGAIN; + npcm_smb_callback(bus, bus->stop_ind, + npcm_smb_get_index(bus)); + } + bus->state = SMB_IDLE; + ret = IRQ_HANDLED; + return ret; + } + + // A Master End of Busy (meaning Stop Condition happened) + // End of Busy int is on and End of Busy is set + if ((FIELD_GET(NPCM_SMBCTL1_EOBINTE, + ioread8(bus->reg + NPCM_SMBCTL1)) == 1) && + (FIELD_GET(NPCM_SMBCST3_EO_BUSY, + ioread8(bus->reg + NPCM_SMBCST3)))) { + NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_EOB); + npcm_smb_eob_int(bus, false); + bus->state = SMB_IDLE; + npcm_smb_callback(bus, bus->stop_ind, bus->rd_ind); + return IRQ_HANDLED; + } + + // Address sent and requested stall occurred (Master mode) + if (FIELD_GET(NPCM_SMBST_STASTR, ioread8(bus->reg + NPCM_SMBST))) { + NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_STALL); + + if (npcm_smb_is_quick(bus)) { + bus->state = SMB_STOP_PENDING; + bus->stop_ind = SMB_MASTER_DONE_IND; + npcm_smb_eob_int(bus, true); + npcm_smb_master_stop(bus); + + } else if ((bus->rd_size == 1) && !bus->read_block_use) { + // Receiving one byte only - set NACK after ensuring + // slave ACKed the address byte + npcm_smb_nack(bus); + } + + // Reset stall-after-address-byte + npcm_smb_stall_after_start(bus, false); + + // Clear stall only after setting STOP + iowrite8(NPCM_SMBST_STASTR, bus->reg + NPCM_SMBST); + + ret = IRQ_HANDLED; + } + + // SDA status is set - TX or RX, master + if (FIELD_GET(NPCM_SMBST_SDAST, ioread8(bus->reg + NPCM_SMBST)) || + (bus->fifo_use && + (npcm_smb_tx_fifo_empty(bus) || npcm_smb_rx_fifo_full(bus)))) { + // Status Bit is cleared by writing to or reading from SDA + // (depending on current direction) + + // Send address: + if (bus->state == SMB_IDLE) { + if (npcm_smb_is_master(bus)) { + bus->stop_ind = SMB_WAKE_UP_IND; + + // test stall on start + if (npcm_smb_is_quick(bus) || + bus->read_block_use) + // Need to stall after successful + // completion of sending address byte + npcm_smb_stall_after_start(bus, true); + else + npcm_smb_stall_after_start(bus, false); + + // Receiving one byte only - stall after + // successful completion of sending address byte + // If we NACK here, and slave doesn't ACK the + // address, we might unintentionally NACK + // the next multi-byte read + if (bus->wr_size == 0 && bus->rd_size == 1) + npcm_smb_stall_after_start(bus, true); + + // Initiate SMBus master transaction + // Generate a Start condition on the SMBus + + // select bank 1 for FIFO regs + npcm_smb_select_bank(bus, SMB_BANK_1); + + fif_cts = ioread8(bus->reg + NPCM_SMBFIF_CTS); + + // clear FIFO and relevant status bits. + iowrite8((fif_cts & ~NPCM_SMBFIF_CTS_SLVRSTR) + | NPCM_SMBFIF_CTS_CLR_FIFO, + bus->reg + NPCM_SMBFIF_CTS); + + // and enable it + iowrite8((fif_cts & ~NPCM_SMBFIF_CTS_SLVRSTR) + | NPCM_SMBFIF_CTS_RXF_TXE, + bus->reg + NPCM_SMBFIF_CTS); + + // Configure the FIFO threshold + // according to the needed # of bytes to read. + // Note: due to HW limitation can't config the + // rx fifo before + // got and ACK on the restart. LAST bit will not + // be reset unless RX completed. + // It will stay set on the next tx. + if (bus->wr_size) + npcm_smb_set_fifo(bus, -1, + bus->wr_size); + else + npcm_smb_set_fifo(bus, bus->rd_size, + -1); + + bus->state = SMB_OPER_STARTED; + + if (npcm_smb_is_quick(bus) || bus->wr_size) + npcm_smb_wr_byte(bus, bus->dest_addr); + else + npcm_smb_wr_byte(bus, bus->dest_addr | + 0x01); + } + + return IRQ_HANDLED; + // SDA status is set - transmit or receive: Handle master mode + } else { + if ((NPCM_SMBST_XMIT & + ioread8(bus->reg + NPCM_SMBST)) == 0) { + bus->operation = SMB_READ_OPER; + npcm_smb_int_master_handler_read(bus); + } else { + bus->operation = SMB_WRITE_OPER; + npcm_smb_int_master_handler_write(bus); + } + } + ret = IRQ_HANDLED; + } + + return ret; +} + +static int npcm_smb_get_SCL(struct i2c_adapter *_adap) +{ + unsigned int ret = 0; + struct npcm_i2c *bus = container_of(_adap, struct npcm_i2c, adap); + u32 offset = 0; + + offset = 0; + ret = FIELD_GET(SMBCTL3_SCL_LVL, ioread32(bus->reg + NPCM_SMBCTL3)); + + pr_debug("i2c%d get SCL 0x%08X\n", bus->num, ret); + + return (ret >> (offset)) & 0x01; +} + +static int npcm_smb_get_SDA(struct i2c_adapter *_adap) +{ + unsigned int ret = 0; + struct npcm_i2c *bus = container_of(_adap, struct npcm_i2c, adap); + u32 offset = 0; + + offset = 0; + ret = FIELD_GET(SMBCTL3_SDA_LVL, ioread32(bus->reg + NPCM_SMBCTL3)); + + pr_debug("i2c%d get SDA 0x%08X\n", bus->num, ret); + + return (ret >> (offset)) & 0x01; +} + +// recovery using TGCLK functionality of the module +static int npcm_smb_recovery_tgclk(struct i2c_adapter *_adap) +{ + int iter = 27; // Allow 3 bytes to be sent by the Slave + int retries = 0; + bool done = false; + int status = -(ENOTRECOVERABLE); + u8 fif_cts; + struct npcm_i2c *bus = container_of(_adap, struct npcm_i2c, adap); + + dev_dbg(bus->dev, "TGCLK recovery bus%d\n", bus->num); + + if ((npcm_smb_get_SDA(_adap) == 1) && (npcm_smb_get_SCL(_adap) == 1)) { + dev_dbg(bus->dev, "TGCLK recovery bus%d: skipped bus not stuck", + bus->num); + npcm_smb_reset(bus); + return status; + } + + // Disable int + npcm_smb_int_enable(bus, false); + + npcm_smb_disable(bus); + npcm_smb_enable(bus); + iowrite8(NPCM_SMBCST_BB, bus->reg + NPCM_SMBCST); + npcm_smb_clear_tx_fifo(bus); + npcm_smb_clear_rx_fifo(bus); + iowrite8(0, bus->reg + NPCM_SMBRXF_CTL); + iowrite8(0, bus->reg + NPCM_SMBTXF_CTL); + npcm_smb_stall_after_start(bus, false); + + // select bank 1 for FIFO regs + npcm_smb_select_bank(bus, SMB_BANK_1); + + fif_cts = ioread8(bus->reg + NPCM_SMBFIF_CTS); + + // clear FIFO and relevant status bits. + iowrite8((fif_cts & ~NPCM_SMBFIF_CTS_SLVRSTR) | + NPCM_SMBFIF_CTS_CLR_FIFO, + bus->reg + NPCM_SMBFIF_CTS); + + npcm_smb_set_fifo(bus, -1, 0); + + // Check If the SDA line is active (low) + if (npcm_smb_get_SDA(_adap) == 0) { + // Repeat the following sequence until SDA is released + do { + // Issue a single SCL cycle + iowrite8(NPCM_SMBCST_TGSCL, bus->reg + NPCM_SMBCST); + retries = 10; + while (retries != 0 && + FIELD_GET(NPCM_SMBCST_TGSCL, + ioread8(bus->reg + NPCM_SMBCST))) { + udelay(20); + retries--; + } + + // tgclk failed to toggle + if (retries == 0) + dev_dbg(bus->dev, "\t toggle timeout\n"); + // If SDA line is inactive (high), stop + if (npcm_smb_get_SDA(_adap)) + done = true; + } while ((!done) && (--iter != 0)); + + // If SDA line is released: send start-addr-stop, to re-sync. + if (done) { + npcm_smb_master_start(bus); + + // Wait until START condition is sent, or RETRIES_NUM + retries = RETRIES_NUM; + while (retries && !npcm_smb_is_master(bus)) { + udelay(20); + retries--; + } + + // If START condition was sent + if (retries > 0) { + // Send an address byte in write direction: + npcm_smb_wr_byte(bus, bus->dest_addr); + udelay(200); + npcm_smb_master_stop(bus); + udelay(200); + status = 0; + } + } + } + + // if bus is still stuck: total reset: set SCL low for 35ms: + if (unlikely(npcm_smb_get_SDA(_adap) == 0)) { + // Generate a START, to synchronize Master and Slave + npcm_smb_master_start(bus); + + // Wait until START condition is sent, or RETRIES_NUM + retries = RETRIES_NUM; + while (retries && !npcm_smb_is_master(bus)) + retries--; + + // set SCL low for a long time (note: this is unlikely) + usleep_range(25000, 35000); + npcm_smb_master_stop(bus); + udelay(200); + status = 0; + } + + dev_dbg(bus->dev, "TGCLK done, iter = %d, done = %d, retries = %d\n", + 27 - iter, done, retries); + // Enable SMB int and New Address Match int source + iowrite8((ioread8(bus->reg + NPCM_SMBCTL1) | NPCM_SMBCTL1_NMINTE) & + ~NPCM_SMBCTL1_RWS_FIELDS, + bus->reg + NPCM_SMBCTL1); + npcm_smb_reset(bus); + npcm_smb_int_enable(bus, true); + return status; +} + +// recovery using bit banging functionality of the module +static int npcm_smb_recovery_init(struct i2c_adapter *_adap) +{ + struct npcm_i2c *bus = container_of(_adap, struct npcm_i2c, adap); + struct i2c_bus_recovery_info *rinfo = &bus->rinfo; + + rinfo->recover_bus = npcm_smb_recovery_tgclk; + rinfo->prepare_recovery = NULL; + rinfo->unprepare_recovery = NULL; + rinfo->set_scl = NULL; + rinfo->set_sda = NULL; + + dev_dbg(bus->dev, "i2c gpio recovery using TGCLK\n"); + + rinfo->get_scl = npcm_smb_get_SCL; + rinfo->get_sda = npcm_smb_get_SDA; + + _adap->bus_recovery_info = rinfo; + + return 0; +} + +static bool npcm_smb_init_clk(struct npcm_i2c *bus, u32 bus_freq) +{ + u32 k1 = 0; + u32 k2 = 0; + u8 dbnct = 0; + u32 sclfrq = 0; + u8 hldt = 7; + bool fast_mode = false; + u32 src_clk_freq; // in KHz + + src_clk_freq = bus->apb_clk / 1000; + bus->bus_freq = bus_freq; + + if (bus_freq <= SMBUS_FREQ_100KHZ) { + sclfrq = src_clk_freq / (bus_freq * 4); + + if (sclfrq < SCLFRQ_MIN || sclfrq > SCLFRQ_MAX) + return false; + + if (src_clk_freq >= 40000) + hldt = 17; + else if (src_clk_freq >= 12500) + hldt = 15; + else + hldt = 7; + } + + else if (bus_freq == SMBUS_FREQ_400KHZ) { + sclfrq = 0; + fast_mode = true; + + if (src_clk_freq < 7500) + // 400KHZ cannot be supported for core clock < 7.5 MHZ + return false; + + else if (src_clk_freq >= 50000) { + k1 = 80; + k2 = 48; + hldt = 12; + dbnct = 7; + } + + // Master or Slave with frequency > 25 MHZ + else if (src_clk_freq > 25000) { + hldt = (u8)__KERNEL_DIV_ROUND_UP(src_clk_freq * 300, + 1000000) + 7; + + k1 = __KERNEL_DIV_ROUND_UP(src_clk_freq * 1600, + 1000000); + k2 = __KERNEL_DIV_ROUND_UP(src_clk_freq * 900, + 1000000); + k1 = round_up(k1, 2); + k2 = round_up(k2 + 1, 2); + if (k1 < SCLFRQ_MIN || k1 > SCLFRQ_MAX || + k2 < SCLFRQ_MIN || k2 > SCLFRQ_MAX) + return false; + } + } + + else if (bus_freq == SMBUS_FREQ_1MHZ) { + sclfrq = 0; + fast_mode = true; + + if (src_clk_freq < 24000) + // 1MHZ cannot be supported for master core clock < 15 MHZ + // or slave core clock < 24 MHZ + return false; + + k1 = round_up((__KERNEL_DIV_ROUND_UP(src_clk_freq * 620, + 1000000)), 2); + k2 = round_up((__KERNEL_DIV_ROUND_UP(src_clk_freq * 380, + 1000000) + 1), 2); + if (k1 < SCLFRQ_MIN || k1 > SCLFRQ_MAX || + k2 < SCLFRQ_MIN || k2 > SCLFRQ_MAX) + return false; + + // Master or Slave with frequency > 40 MHZ + if (src_clk_freq > 40000) { + // Set HLDT: + // SDA hold time: (HLDT-7) * T(CLK) >= 120 + // HLDT = 120/T(CLK) + 7 = 120 * FREQ(CLK) + 7 + hldt = (u8)__KERNEL_DIV_ROUND_UP(src_clk_freq * 120, + 1000000) + 7; + } else { + hldt = 7; + dbnct = 2; + } + } + + // Frequency larger than 1 MHZ + else + return false; + + // After clock parameters calculation update reg (ENABLE should be 0): + iowrite8(FIELD_PREP(SMBCTL2_SCLFRQ6_0, sclfrq & 0x7F), + bus->reg + NPCM_SMBCTL2); + + // force to bank 0, set SCL and fast mode + iowrite8(FIELD_PREP(SMBCTL3_400K_MODE, fast_mode) | + FIELD_PREP(SMBCTL3_SCLFRQ8_7, (sclfrq >> 7) & 0x3), + bus->reg + NPCM_SMBCTL3); + + // Select Bank 0 to access NPCM_SMBCTL4/NPCM_SMBCTL5 + npcm_smb_select_bank(bus, SMB_BANK_0); + + if (bus_freq >= SMBUS_FREQ_400KHZ) { + // Set SCL Low/High Time: + // k1 = 2 * SCLLT7-0 -> Low Time = k1 / 2 + // k2 = 2 * SCLLT7-0 -> High Time = k2 / 2 + iowrite8((u8)k1 / 2, bus->reg + NPCM_SMBSCLLT); + iowrite8((u8)k2 / 2, bus->reg + NPCM_SMBSCLHT); + + iowrite8(dbnct, bus->reg + NPCM_SMBCTL5); + } + + iowrite8(hldt, bus->reg + NPCM_SMBCTL4); + + // Return to Bank 1, and stay there by default: + npcm_smb_select_bank(bus, SMB_BANK_1); + + return true; +} + +static bool npcm_smb_init_module(struct npcm_i2c *bus, enum smb_mode mode, + u32 bus_freq) +{ + // Check whether module already enabled or frequency is out of bounds + if ((bus->state != SMB_DISABLE && bus->state != SMB_IDLE) || + bus_freq < SMBUS_FREQ_MIN || bus_freq > SMBUS_FREQ_MAX) + return false; + + npcm_smb_disable(bus); + + // Configure FIFO mode : + if (FIELD_GET(SMB_VER_FIFO_EN, ioread8(bus->reg + SMB_VER))) { + bus->fifo_use = true; + npcm_smb_select_bank(bus, SMB_BANK_0); + iowrite8(ioread8(bus->reg + NPCM_SMBFIF_CTL) | + NPCM_SMBFIF_CTL_FIFO_EN, bus->reg + NPCM_SMBFIF_CTL); + npcm_smb_select_bank(bus, SMB_BANK_1); + } else { + bus->fifo_use = false; + } + + // Configure SMB module clock frequency + if (!npcm_smb_init_clk(bus, bus_freq)) { + dev_err(bus->dev, "npcm_smb_init_clk failed\n"); + return false; + } + + // Enable module (before configuring CTL1) + npcm_smb_enable(bus); + bus->state = SMB_IDLE; + + // Enable SMB int and New Address Match int source + iowrite8((ioread8(bus->reg + NPCM_SMBCTL1) | NPCM_SMBCTL1_NMINTE) & + ~NPCM_SMBCTL1_RWS_FIELDS, + bus->reg + NPCM_SMBCTL1); + + npcm_smb_int_enable(bus, true); + + npcm_smb_reset(bus); + + return true; +} + +static int __npcm_i2c_init(struct npcm_i2c *bus, struct platform_device *pdev) +{ + u32 clk_freq; + int ret; + + // Initialize the internal data structures + bus->state = SMB_DISABLE; + bus->master_or_slave = SMB_SLAVE; + bus->int_time_stamp = 0; + bus->slave = NULL; + bus->xmits = 0; + + ret = of_property_read_u32(pdev->dev.of_node, + "bus-frequency", &clk_freq); + if (ret < 0) { + dev_err(&pdev->dev, "Could not read bus-frequency property\n"); + clk_freq = 100000; + } + + ret = npcm_smb_init_module(bus, SMB_MASTER, clk_freq / 1000); + if (!ret) { + dev_err(&pdev->dev, + "npcm_smb_init_module() failed\n"); + return -1; + } + + return 0; +} + +static irqreturn_t npcm_i2c_bus_irq(int irq, void *dev_id) +{ + irqreturn_t ret; + struct npcm_i2c *bus = dev_id; + + bus->int_cnt++; + + if (npcm_smb_is_master(bus)) + bus->master_or_slave = SMB_MASTER; + + if (bus->master_or_slave == SMB_MASTER) { + bus->int_time_stamp = jiffies; + ret = npcm_smb_int_master_handler(bus); + if (ret == IRQ_HANDLED) + return ret; + } +#if IS_ENABLED(CONFIG_I2C_SLAVE) + if (bus->slave) { + bus->master_or_slave = SMB_SLAVE; + ret = npcm_smb_int_slave_handler(bus); + if (ret == IRQ_HANDLED) + return ret; + } +#endif + return IRQ_HANDLED; +} + +static bool npcm_smb_master_start_xmit(struct npcm_i2c *bus, + u8 slave_addr, u16 nwrite, u16 nread, + u8 *write_data, u8 *read_data, + bool use_PEC, bool use_read_block) +{ + if (bus->state != SMB_IDLE) { + bus->cmd_err = -(EBUSY); + return false; + } + + bus->xmits++; + + bus->dest_addr = (u8)(slave_addr << 1);// Translate 7bit to 8bit format + bus->wr_buf = write_data; + bus->wr_size = nwrite; + bus->wr_ind = 0; + bus->rd_buf = read_data; + bus->rd_size = nread; + bus->rd_ind = 0; + bus->PEC_use = 0; + + // for write, PEC is appended to buffer from i2c IF. PEC flag is ignored + if (nread) + bus->PEC_use = use_PEC; + bus->read_block_use = use_read_block; + if (nread && !nwrite) + bus->operation = SMB_READ_OPER; + else + bus->operation = SMB_WRITE_OPER; + + bus->int_cnt = 0; + bus->event_log = 0; + + if (bus->fifo_use) { + u8 smbfif_cts; + // select bank 1 for FIFO regs + npcm_smb_select_bank(bus, SMB_BANK_1); + + smbfif_cts = ioread8(bus->reg + NPCM_SMBFIF_CTS); + + // clear FIFO and relevant status bits. + iowrite8((smbfif_cts & (~NPCM_SMBFIF_CTS_SLVRSTR)) | + NPCM_SMBFIF_CTS_CLR_FIFO, + bus->reg + NPCM_SMBFIF_CTS); + } + + bus->state = SMB_IDLE; + + npcm_smb_stall_after_start(bus, true); + npcm_smb_master_start(bus); + + return true; +} + +static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, + int num) +{ + struct npcm_i2c *bus = container_of(adap, struct npcm_i2c, adap); + struct i2c_msg *msg0, *msg1; + unsigned long time_left, flags; + u16 nwrite, nread; + u8 *write_data, *read_data; + u8 slave_addr; + int timeout; + int ret = 0; + bool read_block = false; + bool read_PEC = false; + u8 bus_busy; + unsigned long timeout_usec; + + if (unlikely(bus->state == SMB_DISABLE)) { + dev_err(bus->dev, "I2C%d module is disabled", bus->num); + return -EINVAL; + } + + if (num > 2 || num < 1) { + dev_err(bus->dev, "I2C cmd not supported num of msgs=%d", num); + return -EINVAL; + } + + msg0 = &msgs[0]; + slave_addr = msg0->addr; + if (msg0->flags & I2C_M_RD) { // read + if (num == 2) { + dev_err(bus->dev, "num=2 but 1st msg rd instead of wr"); + return -EINVAL; + } + nwrite = 0; + write_data = NULL; + read_data = msg0->buf; + if (msg0->flags & I2C_M_RECV_LEN) { + nread = 1; + read_block = true; + if (msg0->flags & I2C_CLIENT_PEC) + read_PEC = true; + } else { + nread = msg0->len; + } + } else { // write + nwrite = msg0->len; + write_data = msg0->buf; + nread = 0; + read_data = NULL; + if (num == 2) { + msg1 = &msgs[1]; + read_data = msg1->buf; + if (slave_addr != msg1->addr) { + dev_err(bus->dev, + "SA==%02x but msg1->addr==%02x\n", + slave_addr, msg1->addr); + return -EINVAL; + } + if ((msg1->flags & I2C_M_RD) == 0) { + dev_err(bus->dev, + "num = 2 but both msg are write.\n"); + return -EINVAL; + } + if (msg1->flags & I2C_M_RECV_LEN) { + nread = 1; + read_block = true; + if (msg1->flags & I2C_CLIENT_PEC) + read_PEC = true; + } else { + nread = msg1->len; + read_block = false; + } + } + } + + /* Adaptive TimeOut: astimated time in usec + 100% margin */ + timeout_usec = (2 * 10000 / bus->bus_freq) * (2 + nread + nwrite); + timeout = max(msecs_to_jiffies(35), usecs_to_jiffies(timeout_usec)); + if (nwrite >= 32 * 1024 || nread >= 32 * 1024) { + dev_err(bus->dev, "i2c%d buffer too big\n", bus->num); + return -EINVAL; + } + + time_left = jiffies + + msecs_to_jiffies(DEFAULT_STALL_COUNT) + 1; + do { + /* we must clear slave address immediately when the bus is not + * busy, so we spinlock it, but we don't keep the lock for the + * entire while since it is too long. + */ + spin_lock_irqsave(&bus->lock, flags); + bus_busy = ioread8(bus->reg + NPCM_SMBCST) & NPCM_SMBCST_BB; + if (!bus_busy && bus->slave) + iowrite8((bus->slave->addr & 0x7F), + bus->reg + NPCM_SMBADDR1); + spin_unlock_irqrestore(&bus->lock, flags); + + if (!bus_busy) + break; + } while (time_is_after_jiffies(time_left)); + + if (bus_busy) { + iowrite8(NPCM_SMBCST_BB, bus->reg + NPCM_SMBCST); + npcm_smb_reset(bus); + i2c_recover_bus(adap); + return -EAGAIN; + } + + npcm_smb_init_params(bus); + bus->dest_addr = slave_addr; + bus->msgs = msgs; + bus->msgs_num = num; + bus->read_block_use = read_block; + + reinit_completion(&bus->cmd_complete); + + if (!npcm_smb_master_start_xmit(bus, slave_addr, nwrite, nread, + write_data, read_data, read_PEC, + read_block)) + ret = -(EBUSY); + + if (ret != -(EBUSY)) { + time_left = wait_for_completion_timeout(&bus->cmd_complete, + timeout); + + if (time_left == 0) { + NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_TO); + if (bus->master_or_slave == SMB_MASTER) { + dev_dbg(bus->dev, + "i2c%d TO = %d\n", bus->num, timeout); + i2c_recover_bus(adap); + bus->cmd_err = -EIO; + bus->state = SMB_IDLE; + } + } + } + ret = bus->cmd_err; + + // if there was BER, check if need to recover the bus: + if (bus->cmd_err == -EAGAIN) + i2c_recover_bus(adap); + +#if IS_ENABLED(CONFIG_I2C_SLAVE) + // reenable slave if it was enabled + if (bus->slave) + iowrite8((bus->slave->addr & 0x7F) | NPCM_SMBADDR_SAEN, + bus->reg + NPCM_SMBADDR1); +#endif + + // If nothing went wrong, return number of messages x-ferred. + if (ret >= 0) + return num; + + // print errors apart from NACK + if (bus->cmd_err == -ENXIO) + dev_dbg(bus->dev, "cmd failed cmd_err = %d\n", ret); + return ret; +} + +static u32 npcm_i2c_functionality(struct i2c_adapter *adap) +{ + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_SMBUS_BLOCK_DATA | + I2C_FUNC_SLAVE | I2C_FUNC_SMBUS_PEC; +} + +static const struct i2c_adapter_quirks npcm_i2c_quirks = { + .max_read_len = 32768, + .max_write_len = 32768, + .max_num_msgs = 2, + .flags = I2C_AQ_COMB_WRITE_THEN_READ +}; + +static const struct i2c_algorithm npcm_i2c_algo = { + .master_xfer = npcm_i2c_master_xfer, + .functionality = npcm_i2c_functionality, +#if IS_ENABLED(CONFIG_I2C_SLAVE) + .reg_slave = npcm_i2c_reg_slave, + .unreg_slave = npcm_i2c_unreg_slave, +#endif +}; + +static int npcm_i2c_probe_bus(struct platform_device *pdev) +{ + struct npcm_i2c *bus; + struct i2c_adapter *adap; + struct resource *res; + struct clk *i2c_clk; + int ret; + int num; + + bus = devm_kzalloc(&pdev->dev, sizeof(*bus), GFP_KERNEL); + if (!bus) + return -ENOMEM; + +#ifdef CONFIG_OF + num = of_alias_get_id(pdev->dev.of_node, "i2c"); + bus->num = num; + i2c_clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(i2c_clk)) { + dev_err(bus->dev, " I2C probe failed: can't read clk\n"); + return -EPROBE_DEFER; + } + bus->apb_clk = clk_get_rate(i2c_clk); + dev_dbg(bus->dev, "I2C APB clock is %d\n", bus->apb_clk); +#endif // CONFIG_OF + + gcr_regmap = syscon_regmap_lookup_by_compatible("nuvoton,npcm750-gcr"); + if (IS_ERR(gcr_regmap)) { + dev_err(bus->dev, "%s: failed to find nuvoton,npcm750-gcr\n", + __func__); + return IS_ERR(gcr_regmap); + } + regmap_write(gcr_regmap, NPCM_I2CSEGCTL, I2CSEGCTL_VAL); + dev_dbg(bus->dev, "I2C%d: gcr mapped\n", bus->num); + + clk_regmap = syscon_regmap_lookup_by_compatible("nuvoton,npcm750-clk"); + if (IS_ERR(clk_regmap)) { + dev_err(bus->dev, "%s: failed to find nuvoton,npcm750-clk\n", + __func__); + return IS_ERR(clk_regmap); + } + dev_dbg(bus->dev, "I2C%d: clk mapped\n", bus->num); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + dev_dbg(bus->dev, "resource: %pR\n", res); + bus->reg = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR((bus)->reg)) + return PTR_ERR((bus)->reg); + dev_dbg(bus->dev, "base = %p\n", bus->reg); + + // Initialize the I2C adapter + spin_lock_init(&bus->lock); + init_completion(&bus->cmd_complete); + + adap = &bus->adap; + adap->owner = THIS_MODULE; + adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD | I2C_CLIENT_SLAVE; + adap->retries = 3; + adap->timeout = HZ; + adap->algo = &npcm_i2c_algo; + adap->quirks = &npcm_i2c_quirks; + adap->algo_data = bus; + adap->dev.parent = &pdev->dev; + adap->dev.of_node = pdev->dev.of_node; + adap->nr = pdev->id; + + bus->dev = &pdev->dev; + bus->slave = NULL; + + bus->irq = platform_get_irq(pdev, 0); + if (bus->irq < 0) { + dev_err(bus->dev, "I2C platform_get_irq error\n"); + return -ENODEV; + } + dev_dbg(bus->dev, "irq = %d\n", bus->irq); + + ret = devm_request_irq(&pdev->dev, bus->irq, npcm_i2c_bus_irq, 0, + dev_name(&pdev->dev), (void *)bus); + + if (ret) { + dev_err(&pdev->dev, "I2C%d: request_irq fail\n", bus->num); + return ret; + } + + ret = __npcm_i2c_init(bus, pdev); + if (ret < 0) + return ret; + + ret = npcm_smb_recovery_init(adap); + if (ret) + return ret; + + i2c_set_adapdata(adap, bus); + + snprintf(bus->adap.name, sizeof(bus->adap.name), "Nuvoton i2c"); + + ret = i2c_add_numbered_adapter(&bus->adap); + if (ret < 0) { + dev_err(&pdev->dev, "I2C%d: i2c_add_numbered_adapter fail\n", + bus->num); + return ret; + } + + platform_set_drvdata(pdev, bus); + + pr_info("npcm7xx I2C bus is %d registered\n", bus->adap.nr); + + return 0; +} + +static int npcm_i2c_remove_bus(struct platform_device *pdev) +{ + unsigned long lock_flags; + struct npcm_i2c *bus = platform_get_drvdata(pdev); + + spin_lock_irqsave(&bus->lock, lock_flags); + npcm_smb_disable(bus); + spin_unlock_irqrestore(&bus->lock, lock_flags); + i2c_del_adapter(&bus->adap); + + return 0; +} + +static const struct of_device_id npcm_i2c_bus_of_table[] = { + { .compatible = "nuvoton,npcm750-i2c", }, + {}, +}; +MODULE_DEVICE_TABLE(of, npcm_i2c_bus_of_table); + +static struct platform_driver npcm_i2c_bus_driver = { + .probe = npcm_i2c_probe_bus, + .remove = npcm_i2c_remove_bus, + .driver = { + .name = "nuvoton-i2c", + .of_match_table = npcm_i2c_bus_of_table, + } +}; +module_platform_driver(npcm_i2c_bus_driver); + +MODULE_AUTHOR("Avi Fishman "); +MODULE_AUTHOR("Tali Perry "); +MODULE_AUTHOR("Tyrone Ting "); +MODULE_DESCRIPTION("Nuvoton I2C Bus Driver"); +MODULE_LICENSE("GPL v2"); +MODULE_VERSION(I2C_VERSION);