[v11,5/6] i2c: designware: add SLAVE mode functions

Message ID	bef9f237bed23f0ea05499b085103f7eea9058a1.1497025304.git.lolivei@synopsys.com
State	Changes Requested
Headers	show Return-Path: <linux-i2c-owner@vger.kernel.org> From: Luis Oliveira <Luis.Oliveira@synopsys.com> To: wsa@the-dreams.de, robh+dt@kernel.org, mark.rutland@arm.com, jarkko.nikula@linux.intel.com, andriy.shevchenko@linux.intel.com, mika.westerberg@linux.intel.com, linux-i2c@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Luis.Oliveira@synopsys.com, Ramiro.Oliveira@synopsys.com, Joao.Pinto@synopsys.com, CARLOS.PALMINHA@synopsys.com Subject: [PATCH v11 5/6] i2c: designware: add SLAVE mode functions Date: Wed, 14 Jun 2017 11:43:25 +0100 Message-Id: <bef9f237bed23f0ea05499b085103f7eea9058a1.1497025304.git.lolivei@synopsys.com> In-Reply-To: <cover.1497025304.git.lolivei@synopsys.com> References: <cover.1497025304.git.lolivei@synopsys.com> In-Reply-To: <cover.1497025304.git.lolivei@synopsys.com> References: <cover.1497025304.git.lolivei@synopsys.com> Sender: linux-i2c-owner@vger.kernel.org Precedence: bulk

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 144cbadc7c72..f3f22085e227 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -471,14 +471,26 @@ config I2C_DESIGNWARE_CORE config I2C_DESIGNWARE_PLATFORM tristate "Synopsys DesignWare Platform" select I2C_DESIGNWARE_CORE + select I2C_DESIGNWARE_SLAVE depends on (ACPI && COMMON_CLK) || !ACPI help If you say yes to this option, support will be included for the - Synopsys DesignWare I2C adapter. Only master mode is supported. + Synopsys DesignWare I2C adapter. This driver can also be built as a module. If so, the module will be called i2c-designware-platform. +config I2C_DESIGNWARE_SLAVE + bool "Synopsys DesignWare Slave" + select I2C_SLAVE + depends on I2C_DESIGNWARE_PLATFORM + help + If you say yes to this option, support will be included for the + Synopsys DesignWare I2C slave adapter. + + This is not a standalone module, this module compiles together with + i2c-designware-core. + config I2C_DESIGNWARE_PCI tristate "Synopsys DesignWare PCI" depends on PCI diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index c89a4314c563..142f1b3a96c2 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -41,6 +41,9 @@ obj-$(CONFIG_I2C_CPM) += i2c-cpm.o obj-$(CONFIG_I2C_DAVINCI) += i2c-davinci.o obj-$(CONFIG_I2C_DESIGNWARE_CORE) += i2c-designware-core.o i2c-designware-core-objs := i2c-designware-common.o i2c-designware-master.o +ifneq ($(CONFIG_I2C_DESIGNWARE_SLAVE),n) +i2c-designware-core-objs += i2c-designware-slave.o +endif obj-$(CONFIG_I2C_DESIGNWARE_PLATFORM) += i2c-designware-platform.o i2c-designware-platform-objs := i2c-designware-platdrv.o i2c-designware-platform-$(CONFIG_I2C_DESIGNWARE_BAYTRAIL) += i2c-designware-baytrail.o diff --git a/drivers/i2c/busses/i2c-designware-common.c b/drivers/i2c/busses/i2c-designware-common.c index 0d0ccb73f0e6..d1a69372432f 100644 --- a/drivers/i2c/busses/i2c-designware-common.c +++ b/drivers/i2c/busses/i2c-designware-common.c @@ -56,6 +56,12 @@ static char *abort_sources[] = { "trying to use disabled adapter", [ARB_LOST] = "lost arbitration", + [ABRT_SLAVE_FLUSH_TXFIFO] = + "read command so flush old data in the TX FIFO", + [ABRT_SLAVE_ARBLOST] = + "slave lost the bus while transmitting data to a remote master", + [ABRT_SLAVE_RD_INTX] = + "incorrect slave-transmitter mode configuration", }; u32 dw_readl(struct dw_i2c_dev *dev, int offset) diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h index 76807eafda53..64a39a983410 100644 --- a/drivers/i2c/busses/i2c-designware-core.h +++ b/drivers/i2c/busses/i2c-designware-core.h @@ -305,9 +305,11 @@ u32 i2c_dw_func(struct i2c_adapter *adap); void i2c_dw_disable(struct dw_i2c_dev *dev); void i2c_dw_disable_int(struct dw_i2c_dev *dev); int i2c_dw_init(struct dw_i2c_dev *dev); +int i2c_dw_init_slave(struct dw_i2c_dev *dev); extern u32 i2c_dw_read_comp_param(struct dw_i2c_dev *dev); extern int i2c_dw_probe(struct dw_i2c_dev *dev); +extern int i2c_dw_probe_slave(struct dw_i2c_dev *dev); #if IS_ENABLED(CONFIG_I2C_DESIGNWARE_BAYTRAIL) extern int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev); diff --git a/drivers/i2c/busses/i2c-designware-slave.c b/drivers/i2c/busses/i2c-designware-slave.c new file mode 100644 index 000000000000..84be0b76170d --- /dev/null +++ b/drivers/i2c/busses/i2c-designware-slave.c @@ -0,0 +1,398 @@ +/* + * Synopsys DesignWare I2C adapter driver (slave only). + * + * Based on the Synopsys DesignWare I2C adapter driver (master). + * + * Copyright (C) 2016 Synopsys Inc. + * + * ---------------------------------------------------------------------------- + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * ---------------------------------------------------------------------------- + * + */ +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/errno.h> +#include <linux/i2c.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/pm_runtime.h> + +#include "i2c-designware-core.h" + +static void i2c_dw_configure_fifo_slave(struct dw_i2c_dev *dev) +{ + /* Configure Tx/Rx FIFO threshold levels. */ + dw_writel(dev, 0, DW_IC_TX_TL); + dw_writel(dev, 0, DW_IC_RX_TL); + + /* Configure the I2C slave. */ + dw_writel(dev, dev->slave_cfg, DW_IC_CON); + dw_writel(dev, DW_IC_INTR_SLAVE_MASK, DW_IC_INTR_MASK); +} + +/** + * i2c_dw_init_slave() - Initialize the designware i2c slave hardware + * @dev: device private data + * + * This function configures and enables the I2C in slave mode. + * This function is called during I2C init function, and in case of timeout at + * run time. + */ +int i2c_dw_init_slave(struct dw_i2c_dev *dev) +{ + u32 sda_falling_time, scl_falling_time; + u32 reg, comp_param1; + u32 hcnt, lcnt; + int ret; + + ret = i2c_dw_acquire_lock(dev); + if (ret) + return ret; + + reg = dw_readl(dev, DW_IC_COMP_TYPE); + if (reg == ___constant_swab32(DW_IC_COMP_TYPE_VALUE)) { + /* Configure register endianness access. */ + dev->flags |= ACCESS_SWAP; + } else if (reg == (DW_IC_COMP_TYPE_VALUE & 0x0000ffff)) { + /* Configure register access mode 16bit. */ + dev->flags |= ACCESS_16BIT; + } else if (reg != DW_IC_COMP_TYPE_VALUE) { + dev_err(dev->dev, + "Unknown Synopsys component type: 0x%08x\n", reg); + i2c_dw_release_lock(dev); + return -ENODEV; + } + + comp_param1 = dw_readl(dev, DW_IC_COMP_PARAM_1); + + /* Disable the adapter. */ + __i2c_dw_enable_and_wait(dev, false); + + /* Set standard and fast speed deviders for high/low periods. */ + sda_falling_time = dev->sda_falling_time ?: 300; /* ns */ + scl_falling_time = dev->scl_falling_time ?: 300; /* ns */ + + /* Set SCL timing parameters for standard-mode. */ + if (dev->ss_hcnt && dev->ss_lcnt) { + hcnt = dev->ss_hcnt; + lcnt = dev->ss_lcnt; + } else { + hcnt = i2c_dw_scl_hcnt(i2c_dw_clk_rate(dev), + 4000, /* tHD;STA = tHIGH = 4.0 us */ + sda_falling_time, + 0, /* 0: DW default, 1: Ideal */ + 0); /* No offset */ + lcnt = i2c_dw_scl_lcnt(i2c_dw_clk_rate(dev), + 4700, /* tLOW = 4.7 us */ + scl_falling_time, + 0); /* No offset */ + } + dw_writel(dev, hcnt, DW_IC_SS_SCL_HCNT); + dw_writel(dev, lcnt, DW_IC_SS_SCL_LCNT); + dev_dbg(dev->dev, "Standard-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt); + + /* Set SCL timing parameters for fast-mode or fast-mode plus. */ + if ((dev->clk_freq == 1000000) && dev->fp_hcnt && dev->fp_lcnt) { + hcnt = dev->fp_hcnt; + lcnt = dev->fp_lcnt; + } else if (dev->fs_hcnt && dev->fs_lcnt) { + hcnt = dev->fs_hcnt; + lcnt = dev->fs_lcnt; + } else { + hcnt = i2c_dw_scl_hcnt(i2c_dw_clk_rate(dev), + 600, /* tHD;STA = tHIGH = 0.6 us */ + sda_falling_time, + 0, /* 0: DW default, 1: Ideal */ + 0); /* No offset */ + lcnt = i2c_dw_scl_lcnt(i2c_dw_clk_rate(dev), + 1300, /* tLOW = 1.3 us */ + scl_falling_time, + 0); /* No offset */ + } + dw_writel(dev, hcnt, DW_IC_FS_SCL_HCNT); + dw_writel(dev, lcnt, DW_IC_FS_SCL_LCNT); + dev_dbg(dev->dev, "Fast-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt); + + if ((dev->slave_cfg & DW_IC_CON_SPEED_MASK) == + DW_IC_CON_SPEED_HIGH) { + if ((comp_param1 & DW_IC_COMP_PARAM_1_SPEED_MODE_MASK) + != DW_IC_COMP_PARAM_1_SPEED_MODE_HIGH) { + dev_err(dev->dev, "High Speed not supported!\n"); + dev->slave_cfg &= ~DW_IC_CON_SPEED_MASK; + dev->slave_cfg |= DW_IC_CON_SPEED_FAST; + } else if (dev->hs_hcnt && dev->hs_lcnt) { + hcnt = dev->hs_hcnt; + lcnt = dev->hs_lcnt; + dw_writel(dev, hcnt, DW_IC_HS_SCL_HCNT); + dw_writel(dev, lcnt, DW_IC_HS_SCL_LCNT); + dev_dbg(dev->dev, "HighSpeed-mode HCNT:LCNT = %d:%d\n", + hcnt, lcnt); + } + } + + /* Configure SDA Hold Time if required. */ + reg = dw_readl(dev, DW_IC_COMP_VERSION); + if (reg >= DW_IC_SDA_HOLD_MIN_VERS) { + if (!dev->sda_hold_time) { + /* Keep previous hold time setting if no one set it. */ + dev->sda_hold_time = dw_readl(dev, DW_IC_SDA_HOLD); + } + /* + * Workaround for avoiding TX arbitration lost in case I2C + * slave pulls SDA down "too quickly" after falling egde of + * SCL by enabling non-zero SDA RX hold. Specification says it + * extends incoming SDA low to high transition while SCL is + * high but it apprears to help also above issue. + */ + if (!(dev->sda_hold_time & DW_IC_SDA_HOLD_RX_MASK)) + dev->sda_hold_time |= 1 << DW_IC_SDA_HOLD_RX_SHIFT; + dw_writel(dev, dev->sda_hold_time, DW_IC_SDA_HOLD); + } else { + dev_warn(dev->dev, + "Hardware too old to adjust SDA hold time.\n"); + } + + i2c_dw_configure_fifo_slave(dev); + i2c_dw_release_lock(dev); + + return 0; +} +EXPORT_SYMBOL_GPL(i2c_dw_init_slave); + +int i2c_dw_reg_slave(struct i2c_client *slave) +{ + struct dw_i2c_dev *dev = i2c_get_adapdata(slave->adapter); + + if (dev->slave) + return -EBUSY; + if (slave->flags & I2C_CLIENT_TEN) + return -EAFNOSUPPORT; + /* + * Set slave address in the IC_SAR register, + * the address to which the DW_apb_i2c responds. + */ + __i2c_dw_enable(dev, false); + dw_writel(dev, slave->addr, DW_IC_SAR); + dev->slave = slave; + + __i2c_dw_enable(dev, true); + + dev->cmd_err = 0; + dev->msg_write_idx = 0; + dev->msg_read_idx = 0; + dev->msg_err = 0; + dev->status = STATUS_IDLE; + dev->abort_source = 0; + dev->rx_outstanding = 0; + + return 0; +} + +static int i2c_dw_unreg_slave(struct i2c_client *slave) +{ + struct dw_i2c_dev *dev = i2c_get_adapdata(slave->adapter); + + dev->disable_int(dev); + dev->disable(dev); + dev->slave = NULL; + + return 0; +} + +static u32 i2c_dw_read_clear_intrbits_slave(struct dw_i2c_dev *dev) +{ + u32 stat; + + /* + * The IC_INTR_STAT register just indicates "enabled" interrupts. + * Ths unmasked raw version of interrupt status bits are available + * in the IC_RAW_INTR_STAT register. + * + * That is, + * stat = dw_readl(IC_INTR_STAT); + * equals to, + * stat = dw_readl(IC_RAW_INTR_STAT) & dw_readl(IC_INTR_MASK); + * + * The raw version might be useful for debugging purposes. + */ + stat = dw_readl(dev, DW_IC_INTR_STAT); + + /* + * Do not use the IC_CLR_INTR register to clear interrupts, or + * you'll miss some interrupts, triggered during the period from + * dw_readl(IC_INTR_STAT) to dw_readl(IC_CLR_INTR). + * + * Instead, use the separately-prepared IC_CLR_* registers. + */ + if (stat & DW_IC_INTR_TX_ABRT) + dw_readl(dev, DW_IC_CLR_TX_ABRT); + if (stat & DW_IC_INTR_RX_UNDER) + dw_readl(dev, DW_IC_CLR_RX_UNDER); + if (stat & DW_IC_INTR_RX_OVER) + dw_readl(dev, DW_IC_CLR_RX_OVER); + if (stat & DW_IC_INTR_TX_OVER) + dw_readl(dev, DW_IC_CLR_TX_OVER); + if (stat & DW_IC_INTR_RX_DONE) + dw_readl(dev, DW_IC_CLR_RX_DONE); + if (stat & DW_IC_INTR_ACTIVITY) + dw_readl(dev, DW_IC_CLR_ACTIVITY); + if (stat & DW_IC_INTR_STOP_DET) + dw_readl(dev, DW_IC_CLR_STOP_DET); + if (stat & DW_IC_INTR_START_DET) + dw_readl(dev, DW_IC_CLR_START_DET); + if (stat & DW_IC_INTR_GEN_CALL) + dw_readl(dev, DW_IC_CLR_GEN_CALL); + + return stat; +} + +/* + * Interrupt service routine. This gets called whenever an I2C slave interrupt + * occurs. + */ + +static int i2c_dw_irq_handler_slave(struct dw_i2c_dev *dev) +{ + u32 raw_stat, stat, enabled; + u8 val, slave_activity; + + stat = dw_readl(dev, DW_IC_INTR_STAT); + enabled = dw_readl(dev, DW_IC_ENABLE); + raw_stat = dw_readl(dev, DW_IC_RAW_INTR_STAT); + slave_activity = ((dw_readl(dev, DW_IC_STATUS) & + DW_IC_STATUS_SLAVE_ACTIVITY) >> 6); + + if (!enabled || !(raw_stat & ~DW_IC_INTR_ACTIVITY)) + return 0; + + dev_dbg(dev->dev, + "%#x STAUTS SLAVE_ACTTVITY=%#x : RAW_INTR_STAT=%#x" + " : INTR_STAT=%#x\n", + enabled, slave_activity, raw_stat, stat); + + if ((stat & DW_IC_INTR_RX_FULL) && (stat & DW_IC_INTR_STOP_DET)) + i2c_slave_event(dev->slave, I2C_SLAVE_WRITE_REQUESTED, &val); + + if (stat & DW_IC_INTR_RD_REQ) { + if (slave_activity) { + if (stat & DW_IC_INTR_RX_FULL) { + val = dw_readl(dev, DW_IC_DATA_CMD); + + if (!i2c_slave_event(dev->slave, + I2C_SLAVE_WRITE_RECEIVED, + &val)) { + dev_vdbg(dev->dev, "Byte %X acked!", + val); + } + dw_readl(dev, DW_IC_CLR_RD_REQ); + stat = i2c_dw_read_clear_intrbits_slave(dev); + } else { + dw_readl(dev, DW_IC_CLR_RD_REQ); + dw_readl(dev, DW_IC_CLR_RX_UNDER); + stat = i2c_dw_read_clear_intrbits_slave(dev); + } + if (!i2c_slave_event(dev->slave, + I2C_SLAVE_READ_REQUESTED, + &val)) + dw_writel(dev, val, DW_IC_DATA_CMD); + } + } + + if (stat & DW_IC_INTR_RX_DONE) { + if (!i2c_slave_event(dev->slave, I2C_SLAVE_READ_PROCESSED, + &val)) + dw_readl(dev, DW_IC_CLR_RX_DONE); + + i2c_slave_event(dev->slave, I2C_SLAVE_STOP, &val); + stat = i2c_dw_read_clear_intrbits_slave(dev); + return 1; + } + + if (stat & DW_IC_INTR_RX_FULL) { + val = dw_readl(dev, DW_IC_DATA_CMD); + if (!i2c_slave_event(dev->slave, I2C_SLAVE_WRITE_RECEIVED, + &val)) + dev_vdbg(dev->dev, "Byte %X acked!", val); + } else { + i2c_slave_event(dev->slave, I2C_SLAVE_STOP, &val); + stat = i2c_dw_read_clear_intrbits_slave(dev); + } + + //~ if (stat & DW_IC_INTR_TX_OVER) + //~ dw_readl(dev, DW_IC_CLR_TX_OVER); + + return 1; +} + +static irqreturn_t i2c_dw_isr_slave(int this_irq, void *dev_id) +{ + struct dw_i2c_dev *dev = dev_id; + int ret; + + i2c_dw_read_clear_intrbits_slave(dev); + ret = i2c_dw_irq_handler_slave(dev); + if (ret > 0) + complete(&dev->cmd_complete); + + return IRQ_RETVAL(ret); +} + +static struct i2c_algorithm i2c_dw_algo = { + .functionality = i2c_dw_func, + .reg_slave = i2c_dw_reg_slave, + .unreg_slave = i2c_dw_unreg_slave, +}; + +int i2c_dw_probe_slave(struct dw_i2c_dev *dev) +{ + struct i2c_adapter *adap = &dev->adapter; + int ret; + + init_completion(&dev->cmd_complete); + + dev->init = i2c_dw_init_slave; + dev->disable = i2c_dw_disable; + dev->disable_int = i2c_dw_disable_int; + + ret = dev->init(dev); + if (ret) + return ret; + + snprintf(adap->name, sizeof(adap->name), + "Synopsys DesignWare I2C Slave adapter"); + adap->retries = 3; + adap->algo = &i2c_dw_algo; + adap->dev.parent = dev->dev; + i2c_set_adapdata(adap, dev); + + ret = devm_request_irq(dev->dev, dev->irq, i2c_dw_isr_slave, + IRQF_SHARED, dev_name(dev->dev), dev); + if (ret) { + dev_err(dev->dev, "failure requesting irq %i: %d\n", + dev->irq, ret); + return ret; + } + + ret = i2c_add_numbered_adapter(adap); + if (ret) + dev_err(dev->dev, "failure adding adapter: %d\n", ret); + pm_runtime_put_noidle(dev->dev); + + return ret; +} +EXPORT_SYMBOL_GPL(i2c_dw_probe_slave); + +MODULE_AUTHOR("Luis Oliveira <lolivei@synopsys.com>"); +MODULE_DESCRIPTION("Synopsys DesignWare I2C bus slave adapter"); +MODULE_LICENSE("GPL v2");

[v11,5/6] i2c: designware: add SLAVE mode functions

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