From patchwork Mon Apr 8 17:15:19 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Strasser X-Patchwork-Id: 234845 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id A51002C0040 for ; Tue, 9 Apr 2013 03:18:15 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934862Ab3DHRSC (ORCPT ); Mon, 8 Apr 2013 13:18:02 -0400 Received: from mga09.intel.com ([134.134.136.24]:38822 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934597Ab3DHRSA (ORCPT ); Mon, 8 Apr 2013 13:18:00 -0400 Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga102.jf.intel.com with ESMTP; 08 Apr 2013 10:16:10 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.87,432,1363158000"; d="scan'208";a="291854090" Received: from wrk.jf.intel.com ([10.7.202.171]) by orsmga001.jf.intel.com with ESMTP; 08 Apr 2013 10:17:53 -0700 From: Kevin Strasser To: linux-kernel@vger.kernel.org Cc: Michael Brunner , Samuel Ortiz , Wolfram Sang , Ben Dooks , linux-i2c@vger.kernel.org, Grant Likely , Linus Walleij , Wim Van Sebroeck , linux-watchdog@vger.kernel.org, Darren Hart , Michael Brunner , Greg Kroah-Hartman , Kevin Strasser Subject: [PATCH 2/4] i2c: Kontron PLD i2c bus driver Date: Mon, 8 Apr 2013 10:15:19 -0700 Message-Id: <1365441321-21952-2-git-send-email-kevin.strasser@linux.intel.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1365441321-21952-1-git-send-email-kevin.strasser@linux.intel.com> References: <1365441321-21952-1-git-send-email-kevin.strasser@linux.intel.com> Sender: linux-i2c-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org From: Michael Brunner Add i2c support for the on-board PLD found on some Kontron embedded modules. Signed-off-by: Michael Brunner Signed-off-by: Kevin Strasser --- drivers/i2c/busses/Kconfig | 20 ++ drivers/i2c/busses/Makefile | 1 + drivers/i2c/busses/i2c-kempld.c | 679 +++++++++++++++++++++++++++++++++++++++ drivers/i2c/busses/i2c-kempld.h | 86 +++++ 4 files changed, 786 insertions(+) create mode 100644 drivers/i2c/busses/i2c-kempld.c create mode 100644 drivers/i2c/busses/i2c-kempld.h diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index adfee98..7aecd61 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -494,6 +494,26 @@ config I2C_IOP3XX This driver can also be built as a module. If so, the module will be called i2c-iop3xx. +config I2C_KEMPLD + tristate "Kontron COM I2C" + depends on MFD_KEMPLD + help + This enables support for the I2C bus interface on some Kontron ETX + and COMexpress (ETXexpress) modules. + + This driver can also be built as a module. If so, the module + will be called i2c-kempld. + +config I2C_KEMPLD_MUX + bool "Enable MUXed I2C ports (EXPERIMENTAL)" + depends on I2C_KEMPLD && I2C_MUX + default n + help + This enables support for additional I2C ports available on some + modules. Usually those ports are for board internal usage and + not routed outside the module. + Do not use this option unless you know what you are doing! + config I2C_MPC tristate "MPC107/824x/85xx/512x/52xx/83xx/86xx" depends on PPC diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 8f4fc23..411b8ce 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -48,6 +48,7 @@ obj-$(CONFIG_I2C_IBM_IIC) += i2c-ibm_iic.o obj-$(CONFIG_I2C_IMX) += i2c-imx.o obj-$(CONFIG_I2C_INTEL_MID) += i2c-intel-mid.o obj-$(CONFIG_I2C_IOP3XX) += i2c-iop3xx.o +obj-$(CONFIG_I2C_KEMPLD) += i2c-kempld.o obj-$(CONFIG_I2C_MPC) += i2c-mpc.o obj-$(CONFIG_I2C_MV64XXX) += i2c-mv64xxx.o obj-$(CONFIG_I2C_MXS) += i2c-mxs.o diff --git a/drivers/i2c/busses/i2c-kempld.c b/drivers/i2c/busses/i2c-kempld.c new file mode 100644 index 0000000..c6b44e7 --- /dev/null +++ b/drivers/i2c/busses/i2c-kempld.c @@ -0,0 +1,679 @@ +/* + * i2c-kempld.c: I2C bus driver for Kontron COM modules + * + * Copyright (c) 2010-2013 Kontron Europe GmbH + * Author: Michael Brunner + * + * The driver is based on the i2c-ocores driver by Peter Korsgaard. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License 2 as published + * by the Free Software Foundation. + * + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; see the file COPYING. If not, write to + * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include +#include +#include +#include +#include +#include +#ifdef CONFIG_I2C_KEMPLD_MUX +#include +#endif +#include +#include +#include +#include +#include + +#include "i2c-kempld.h" + +static int scl_frequency; +static int i2c_bus = -1; +static int i2c_mx_bus = -1; +static bool force_polling; +static int i2c_gpio_mux = -1; + +#ifdef CONFIG_I2C_KEMPLD_MUX +static int kempld_i2cmux_select(struct i2c_adapter *adap, void *data, u32 chan) +{ + struct kempld_i2c_data *i2c = data; + struct kempld_device_data *pld = i2c->pld; + int ret = 0; + + if ((i2c->state == STATE_DONE) + || (i2c->state == STATE_ERROR)) { + if (i2c->mx != chan) { + kempld_get_mutex_set_index(pld, KEMPLD_I2C_MX); + i2c->mx = chan & 0x0f; + kempld_write8(pld, KEMPLD_I2C_MX, i2c->mx); + kempld_release_mutex(pld); + } + + /* Reset controller if the last transfer ended with an error */ + if (i2c->state == STATE_ERROR) { + u8 ctrl; + + kempld_get_mutex_set_index(pld, KEMPLD_I2C_CMD); + ctrl = kempld_read8(pld, KEMPLD_I2C_CONTROL); + ctrl &= ~OCI2C_CTRL_EN; + kempld_write8(pld, KEMPLD_I2C_CONTROL, ctrl); + kempld_write8(pld, KEMPLD_I2C_CMD, OCI2C_CMD_IACK); + ctrl |= OCI2C_CTRL_EN; + kempld_write8(pld, KEMPLD_I2C_CONTROL, ctrl); + kempld_release_mutex(pld); + } + + } else + ret = -EBUSY; + + return ret; +} + +static void kempld_i2cmux_del(struct kempld_i2c_data *i2c) +{ + int i; + + for (i = 0; i <= i2c->mx_max; i++) { + if (i2c->mxadap[i]) { + i2c_del_mux_adapter(i2c->mxadap[i]); + i2c->mxadap[i] = NULL; + } + } +} + +static int kempld_i2cmux_add(struct kempld_i2c_data *i2c) +{ + struct kempld_device_data *pld = i2c->pld; + int i; + int ret = -ENODEV; + + for (i = 0; (i <= (i2c->mx_max)); i++) { + i2c->mxadap[i] = i2c_add_mux_adapter(&i2c->adap, + NULL, i2c, 0, i, 0, + kempld_i2cmux_select, + NULL); + if (!i2c->mxadap[i]) { + ret = -ENODEV; + dev_err(pld->dev, + "Failed to register MUX adapter %d\n", i); + goto add_mux_adapter_failed; + } + } + + return 0; + +add_mux_adapter_failed: + kempld_i2cmux_del(i2c); + + return ret; +} + +#else +#define kempld_i2cmux_add(x) (0) +#define kempld_i2cmux_del(x) do {} while (0) +#endif + +static int kempld_i2c_process(struct kempld_i2c_data *i2c) +{ + struct kempld_device_data *pld = i2c->pld; + struct i2c_msg *msg = i2c->msg; + u8 stat = kempld_read8(pld, KEMPLD_I2C_STATUS); + + /* ready? */ + if (stat & OCI2C_STAT_TIP) + return -EBUSY; + + if ((i2c->state == STATE_DONE) || (i2c->state == STATE_ERROR)) { + /* stop has been sent */ + kempld_write8(pld, KEMPLD_I2C_CMD, OCI2C_CMD_IACK); + if (i2c->irq) + wake_up(&i2c->wait); + if (i2c->state == STATE_ERROR) + return -EIO; + else + return 0; + } + + /* error? */ + if (stat & OCI2C_STAT_ARBLOST) { + i2c->state = STATE_ERROR; + kempld_write8(pld, KEMPLD_I2C_CMD, OCI2C_CMD_STOP); + return -EAGAIN; + } + + if (i2c->state == STATE_INIT) { + /* check if bus is free */ + if (stat & OCI2C_STAT_BUSY) + return -EBUSY; + + i2c->state = STATE_ADDR; + } + + if (i2c->state == STATE_ADDR) { + u8 addr; + /* 10 bit address? */ + if (i2c->msg->flags & I2C_M_TEN) { + addr = 0xf0 | ((i2c->msg->addr >> 7) & 0x6); + i2c->state = STATE_ADDR10; + } else { + addr = (i2c->msg->addr << 1); + i2c->state = STATE_START; + } + + /* set read bit if necessary */ + addr |= (i2c->msg->flags & I2C_M_RD) ? 1 : 0; + + kempld_write8(pld, KEMPLD_I2C_DATA, addr); + kempld_write8(pld, KEMPLD_I2C_CMD, OCI2C_CMD_START); + + return 0; + } + + /* second part of 10 bit addressing */ + if (i2c->state == STATE_ADDR10) { + kempld_write8(pld, KEMPLD_I2C_DATA, i2c->msg->addr & 0xff); + kempld_write8(pld, KEMPLD_I2C_CMD, OCI2C_CMD_WRITE); + + i2c->state = STATE_START; + return 0; + } + + if ((i2c->state == STATE_START) || (i2c->state == STATE_WRITE)) { + i2c->state = + (msg->flags & I2C_M_RD) ? STATE_READ : STATE_WRITE; + + if (stat & OCI2C_STAT_NACK) { + i2c->state = STATE_ERROR; + kempld_write8(pld, KEMPLD_I2C_CMD, OCI2C_CMD_STOP); + return -ENXIO; + } + } else + msg->buf[i2c->pos++] = kempld_read8(pld, KEMPLD_I2C_DATA); + + /* end of msg? */ + if (i2c->pos >= msg->len) { + i2c->nmsgs--; + i2c->msg++; + i2c->pos = 0; + msg = i2c->msg; + + if (i2c->nmsgs) { /* end? */ + /* send start? */ + if (!(msg->flags & I2C_M_NOSTART)) { + i2c->state = STATE_ADDR; + if (i2c->irq) + wake_up(&i2c->wait); + return 0; + } else + i2c->state = (msg->flags & I2C_M_RD) + ? STATE_READ : STATE_WRITE; + } else { + i2c->state = STATE_DONE; + kempld_write8(pld, KEMPLD_I2C_CMD, OCI2C_CMD_STOP); + return 0; + } + } + + if (i2c->state == STATE_READ) { + kempld_write8(pld, KEMPLD_I2C_CMD, i2c->pos == (msg->len-1) ? + OCI2C_CMD_READ_NACK : OCI2C_CMD_READ_ACK); + } else { + kempld_write8(pld, KEMPLD_I2C_DATA, msg->buf[i2c->pos++]); + kempld_write8(pld, KEMPLD_I2C_CMD, OCI2C_CMD_WRITE); + } + + return 0; +} + +static irqreturn_t kempld_i2c_isr(int irq, void *dev_id) +{ + struct kempld_i2c_data *i2c = dev_id; + + /* The actual ISR handler is put into a tasklet as it may block + * and therefore rescheduling must be possible */ + tasklet_schedule(&i2c->tasklet); + + return IRQ_HANDLED; +} + +void kempld_i2c_tasklet(unsigned long data) +{ + struct kempld_i2c_data *i2c = (struct kempld_i2c_data *)data; + struct kempld_device_data *pld = i2c->pld; + + kempld_get_mutex_set_index(pld, KEMPLD_I2C_STATUS); + kempld_i2c_process(i2c); + kempld_release_mutex(pld); +} + +static int kempld_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, + int num) +{ + struct kempld_i2c_data *i2c = i2c_get_adapdata(adap); + struct kempld_device_data *pld = i2c->pld; + unsigned long timeout = jiffies + HZ; + int ret; + + i2c->msg = msgs; + i2c->pos = 0; + i2c->nmsgs = num; + i2c->state = STATE_INIT; + + /* handle the transfer */ + while (time_before(jiffies, timeout)) { + kempld_get_mutex_set_index(pld, KEMPLD_I2C_STATUS); + ret = kempld_i2c_process(i2c); + kempld_release_mutex(pld); + + if (i2c->irq && ((i2c->state >= STATE_START) + || (i2c->state == STATE_ERROR))) { + wait_event_timeout(i2c->wait, + (i2c->state == STATE_ERROR) || + (i2c->state == STATE_DONE) || + (i2c->state == STATE_ADDR), HZ); + if (i2c->state == STATE_ERROR) + ret = -EIO; + } + + if ((i2c->state == STATE_DONE) + || (i2c->state == STATE_ERROR)) + return (i2c->state == STATE_DONE) ? num : ret; + + if (ret == 0) + timeout = jiffies + HZ; + + usleep_range(5, 15); + } + + i2c->state = STATE_ERROR; + + return -ETIMEDOUT; +} + +static void kempld_i2c_device_init(struct kempld_i2c_data *i2c) +{ + struct kempld_device_data *pld = i2c->pld; + long prescale; + u16 prescale_corr; + u8 cfg; + u8 ctrl; + u8 stat; + u8 mx; + + kempld_get_mutex_set_index(pld, KEMPLD_I2C_CONTROL); + + ctrl = kempld_read8(pld, KEMPLD_I2C_CONTROL); + if (ctrl & OCI2C_CTRL_EN) + i2c->was_active = 1; + + /* set bus frequency */ + if (scl_frequency > 0) { + /* make sure the device is disabled */ + ctrl &= ~(OCI2C_CTRL_EN|OCI2C_CTRL_IEN); + kempld_write8(pld, KEMPLD_I2C_CONTROL, ctrl); + + /* The clock frequency calculation has been changed a bit + * between the spec. revisions */ + if (pld->info.spec_major == 1) + prescale = (pld->pld_clock / (scl_frequency*5)) - 1000; + else + prescale = (pld->pld_clock / (scl_frequency*4)) - 3000; + + /* Prevent negative prescaler values */ + if (prescale < 0) + prescale = 0; + + /* Round to the best matching value */ + prescale_corr = prescale / 1000; + if ((prescale % 1000) >= 500) + prescale_corr++; + + kempld_write8(pld, KEMPLD_I2C_PRELOW, prescale_corr & 0xff); + kempld_write8(pld, KEMPLD_I2C_PREHIGH, prescale_corr >> 8); + } + + /* Activate I2C bus output on GPIO pins */ + if (i2c_gpio_mux > -1) { + cfg = kempld_read8(pld, KEMPLD_CFG); + if (i2c_gpio_mux) + cfg |= KEMPLD_CFG_GPIO_I2C_MUX; + else + cfg &= ~KEMPLD_CFG_GPIO_I2C_MUX; + kempld_write8(pld, KEMPLD_CFG, cfg); + } + cfg = kempld_read8(pld, KEMPLD_CFG); + if (cfg & KEMPLD_CFG_GPIO_I2C_MUX) + i2c->gpio_mux = 1; + else + i2c->gpio_mux = 0; + if (((i2c_gpio_mux > 0) && (!i2c->gpio_mux)) + || ((i2c_gpio_mux == 0) && (i2c->gpio_mux))) + dev_warn(pld->dev, "Unable to change GPIO I2C MUX setting\n"); + + /* Check how much multiplexed I2C busses we have */ + mx = kempld_read8(pld, KEMPLD_I2C_MX); + if (pld->info.spec_major > 1) { + i2c->mx_max = KEMPLD_I2C_MX_GET_MAX(mx); + if (i2c->mx_max == 0xf) /* No multiplexer available */ + i2c->mx_max = 0; + } else + i2c->mx_max = 1; + /* 2 busses should be enough for all + * boards using specification revision 1 */ + + /* Check which MX setting should be set */ + if ((i2c_mx_bus == -1) || (i2c_mx_bus > i2c->mx_max)) { + if (i2c_mx_bus > i2c->mx_max) { + dev_err(pld->dev, + "bus selected with i2c_mx_bus not available " + "- leaving MX setting unchanged\n"); + } + i2c->mx = mx & KEMPLD_I2C_MX_MASK; + } else + i2c->mx = i2c_mx_bus; + + /* Connect the controller to the chosen bus output */ + kempld_write8(pld, KEMPLD_I2C_MX, i2c->mx); + + /* enable the device */ + kempld_write8(pld, KEMPLD_I2C_CMD, OCI2C_CMD_IACK); + ctrl |= OCI2C_CTRL_EN; + kempld_write8(pld, KEMPLD_I2C_CONTROL, ctrl); + + /* If bus is busy send a STOP signal to be sure the controller is + * not hanging... */ + stat = kempld_read8(pld, KEMPLD_I2C_STATUS); + if (stat & OCI2C_STAT_BUSY) { + dev_warn(pld->dev, + "I2C bus is busy - generating stop signal\n"); + kempld_write8(pld, KEMPLD_I2C_CMD, OCI2C_CMD_STOP); + } + + kempld_release_mutex(pld); + + if ((pld->info.spec_major == 1) && (i2c->mx == 0xf)) + i2c->mx = 0; +} + +static void kempld_i2c_irq_enable(struct kempld_i2c_data *i2c) +{ + struct kempld_device_data *pld = i2c->pld; + u8 irq, ctrl; + int ret; + + irq = i2c->irq; + + /* This only has to be done once */ + if (i2c->irq == 0) { + kempld_get_mutex_set_index(pld, KEMPLD_IRQ_I2C); + irq = kempld_read8(pld, KEMPLD_IRQ_I2C); + kempld_release_mutex(pld); + + /* Leave if interrupts are not supported by the I2C core */ + if ((irq & 0xf0) == 0xf0) + return; + irq &= 0x0f; + if (irq == 0) + return; + + /* Initialize interrupt handlers if not already done */ + init_waitqueue_head(&i2c->wait); + tasklet_init(&i2c->tasklet, kempld_i2c_tasklet, + (unsigned long)i2c); + + ret = devm_request_irq(pld->dev, irq, kempld_i2c_isr, + IRQF_SHARED, i2c->adap.name, i2c); + if (ret) { + dev_err(pld->dev, + "Unable to claim IRQ - using polling mode\n"); + return; + } + } + + /* Now enable interrupts in the controller */ + kempld_get_mutex_set_index(pld, KEMPLD_I2C_CONTROL); + ctrl = kempld_read8(pld, KEMPLD_I2C_CONTROL); + ctrl |= OCI2C_CTRL_IEN; + kempld_write8(pld, KEMPLD_I2C_CONTROL, ctrl); + kempld_release_mutex(pld); + + i2c->irq = irq & 0x0f; +} + +static void kempld_i2c_irq_disable(struct kempld_i2c_data *i2c) +{ + struct kempld_device_data *pld = i2c->pld; + u8 ctrl; + int irq; + + if (i2c->irq == 0) + return; + + irq = i2c->irq; + i2c->irq = 0; + + tasklet_kill(&i2c->tasklet); + + kempld_get_mutex_set_index(pld, KEMPLD_I2C_CONTROL); + ctrl = kempld_read8(pld, KEMPLD_I2C_CONTROL); + ctrl &= ~OCI2C_CTRL_IEN; + kempld_write8(pld, KEMPLD_I2C_CONTROL, ctrl); + kempld_release_mutex(pld); + + devm_free_irq(pld->dev, irq, i2c); +} + +static u32 kempld_i2c_func(struct i2c_adapter *adap) +{ + return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR + | I2C_FUNC_SMBUS_EMUL; +} + +static const struct i2c_algorithm kempld_i2c_algorithm = { + .master_xfer = kempld_i2c_xfer, + .functionality = kempld_i2c_func, +}; + +static struct i2c_adapter kempld_i2c_adapter = { + .owner = THIS_MODULE, + .name = "i2c-kempld", + .class = I2C_CLASS_HWMON | I2C_CLASS_SPD, + .algo = &kempld_i2c_algorithm, +}; + +static int kempld_i2c_get_scl_frequency(struct kempld_i2c_data *i2c) +{ + struct kempld_device_data *pld = i2c->pld; + int frequency; + u16 prescale; + + kempld_get_mutex_set_index(pld, KEMPLD_I2C_PRELOW); + + prescale = kempld_read8(pld, KEMPLD_I2C_PRELOW) + | kempld_read8(pld, KEMPLD_I2C_PREHIGH)<<8; + + kempld_release_mutex(pld); + + /* The clock frequency calculation has been changed a bit + * between the spec. revisions */ + if (pld->info.spec_major == 1) + frequency = (pld->pld_clock / (prescale + 1)) / 5000; + else + frequency = (pld->pld_clock / (prescale + 3)) / 4000; + + return frequency; +} + +static int kempld_i2c_probe(struct platform_device *pdev) +{ + struct kempld_i2c_data *i2c; + struct kempld_device_data *pld; + int ret; + + pld = dev_get_drvdata(pdev->dev.parent); + + i2c = kzalloc(sizeof(*i2c), GFP_KERNEL); + if (!i2c) + return -ENOMEM; + + i2c->pld = pld; + + kempld_i2c_device_init(i2c); + + /* hook up driver to tree */ + platform_set_drvdata(pdev, i2c); + i2c->adap = kempld_i2c_adapter; + i2c_set_adapdata(&i2c->adap, i2c); + i2c->adap.dev.parent = &pdev->dev; + + i2c->irq = 0; + if (!force_polling) + kempld_i2c_irq_enable(i2c); + + /* add I2C adapter to I2C tree */ + i2c->adap.nr = i2c_bus; + ret = i2c_add_numbered_adapter(&i2c->adap); + if (ret) { + dev_err(&pdev->dev, "Failed to add adapter\n"); + goto add_adapter_failed; + } + + ret = kempld_i2cmux_add(i2c); + if (ret) + goto add_mux_adapters_failed; + + dev_info(pld->dev, "I2C bus initialized with %d kHz SCL frequency\n", + kempld_i2c_get_scl_frequency(i2c)); + dev_info(pld->dev, "I2C MUX connected to bus %d (available: %s%d)\n", + i2c->mx, i2c->mx_max ? "0-" : "", i2c->mx_max); + dev_info(pld->dev, "I2C IRQs %s\n", i2c->irq ? "enabled" : "disabled"); + if (i2c->gpio_mux) + dev_info(pld->dev, "GPIO I2C MUX pins enabled\n"); + + return 0; + +add_mux_adapters_failed: + i2c_del_adapter(&i2c->adap); +add_adapter_failed: + kfree(i2c); + + return ret; +} + +static int kempld_i2c_remove(struct platform_device *pdev) +{ + struct kempld_i2c_data *i2c = platform_get_drvdata(pdev); + struct kempld_device_data *pld = i2c->pld; + u8 ctrl; + + kempld_i2c_irq_disable(i2c); + + if (!i2c->was_active) { + /* disable I2C logic if it was not activated before the + * driver loaded */ + kempld_get_mutex_set_index(pld, KEMPLD_I2C_CONTROL); + ctrl = kempld_read8(pld, KEMPLD_I2C_CONTROL); + ctrl &= ~OCI2C_CTRL_EN; + kempld_write8(pld, KEMPLD_I2C_CONTROL, ctrl); + kempld_release_mutex(pld); + } + + /* remove adapter & data */ + kempld_i2cmux_del(i2c); + i2c_del_adapter(&i2c->adap); + + platform_set_drvdata(pdev, NULL); + + kfree(i2c); + + return 0; +} + +#ifdef CONFIG_PM +static int kempld_i2c_suspend(struct platform_device *pdev, pm_message_t state) +{ + struct kempld_i2c_data *i2c = platform_get_drvdata(pdev); + struct kempld_device_data *pld = i2c->pld; + u8 ctrl; + + kempld_i2c_irq_disable(i2c); + + if (!i2c->was_active) { + /* make sure the device is disabled */ + kempld_get_mutex_set_index(pld, KEMPLD_I2C_CONTROL); + ctrl = kempld_read8(pld, KEMPLD_I2C_CONTROL); + ctrl &= ~OCI2C_CTRL_EN; + kempld_write8(pld, KEMPLD_I2C_CONTROL, ctrl); + kempld_release_mutex(pld); + } + + return 0; +} + +static int kempld_i2c_resume(struct platform_device *pdev) +{ + struct kempld_i2c_data *i2c = platform_get_drvdata(pdev); + + kempld_i2c_device_init(i2c); + kempld_i2c_irq_enable(i2c); + + return 0; +} +#else +#define kempld_i2c_suspend NULL +#define kempld_i2c_resume NULL +#endif + +static struct platform_driver kempld_i2c_driver = { + .driver = { + .name = "kempld-i2c", + .owner = THIS_MODULE, + }, + .probe = kempld_i2c_probe, + .remove = kempld_i2c_remove, + .suspend = kempld_i2c_suspend, + .resume = kempld_i2c_resume, +}; + +static int __init kempld_i2c_init(void) +{ + /* Check if a valid value for the i2c_mx_bus parameter is provided */ + if ((i2c_mx_bus != -1) && (i2c_mx_bus & ~KEMPLD_I2C_MX_MASK)) + return -EINVAL; + + return platform_driver_register(&kempld_i2c_driver); +} + +static void __exit kempld_i2c_exit(void) +{ + platform_driver_unregister(&kempld_i2c_driver); +} + +module_init(kempld_i2c_init); +module_exit(kempld_i2c_exit); + +module_param(scl_frequency, int, 0); +module_param(i2c_bus, int, 0); +module_param(i2c_mx_bus, int, 0); +module_param(force_polling, bool, 0); +module_param(i2c_gpio_mux, int, 0); + +MODULE_DESCRIPTION("KEM PLD I2C Driver"); +MODULE_AUTHOR("Michael Brunner "); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:kempld_i2c"); +MODULE_PARM_DESC(scl_frequency, "Set I2C SCL frequency (in kHz) default=0"); +MODULE_PARM_DESC(i2c_bus, "Set I2C bus (-1 for dynamic assignment"); +MODULE_PARM_DESC(i2c_mx_bus, "Set I2C MX bus (0-15, default=-1 (FW default))"); +MODULE_PARM_DESC(force_polling, "Force polling mode"); +MODULE_PARM_DESC(i2c_gpio_mux, "Enable I2C port on GPIO out"); diff --git a/drivers/i2c/busses/i2c-kempld.h b/drivers/i2c/busses/i2c-kempld.h new file mode 100644 index 0000000..2229662 --- /dev/null +++ b/drivers/i2c/busses/i2c-kempld.h @@ -0,0 +1,86 @@ +/* + * i2c-kempld.h - Kontron PLD I2C driver definitions + * + * Copyright (c) 2010-2012 Kontron Europe GmbH + * Author: Michael Brunner + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License 2 as published + * by the Free Software Foundation. + * + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; see the file COPYING. If not, write to + * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#ifndef _KEMPLD_I2C_H_ +#define _KEMPLD_I2C_H_ + +struct kempld_i2c_data { + struct i2c_adapter adap; + struct i2c_adapter *mxadap[15]; + struct i2c_msg *msg; + int pos; + int nmsgs; + int state; /* see STATE_ */ + int was_active; + int mx; + int mx_max; + int gpio_mux; + wait_queue_head_t wait; + struct tasklet_struct tasklet; + int irq; + struct kempld_device_data *pld; +}; + +/* I2C register definitions */ +#define KEMPLD_I2C_PRELOW 0x0b +#define KEMPLD_I2C_PREHIGH 0x0c +#define KEMPLD_I2C_CONTROL 0x0d +#define KEMPLD_I2C_DATA 0x0e +#define KEMPLD_I2C_CMD 0x0f /* write only */ +#define KEMPLD_I2C_CMD_STA 0x80 +#define KEMPLD_I2C_CMD_STO 0x40 +#define KEMPLD_I2C_CMD_RD 0x20 +#define KEMPLD_I2C_CMD_WR 0x10 +#define KEMPLD_I2C_CMD_NACK 0x08 +#define KEMPLD_I2C_CMD_IACK 0x01 +#define KEMPLD_I2C_STATUS 0x0f /* read only, same address as + KEMPLD_I2C_CMD */ +#define KEMPLD_I2C_MX 0x15 +#define KEMPLD_I2C_MX_GET_MAX(x) ((x & 0xf0)>>4) +#define KEMPLD_I2C_MX_MASK 0x0f + +#define STATE_DONE 0 +#define STATE_INIT 1 +#define STATE_ADDR 2 +#define STATE_ADDR10 3 +#define STATE_START 4 +#define STATE_WRITE 5 +#define STATE_READ 6 +#define STATE_ERROR 7 + +/* defines taken from i2c-ocores */ +#define OCI2C_CTRL_IEN 0x40 +#define OCI2C_CTRL_EN 0x80 + +#define OCI2C_CMD_START 0x91 +#define OCI2C_CMD_STOP 0x41 +#define OCI2C_CMD_READ 0x21 +#define OCI2C_CMD_WRITE 0x11 +#define OCI2C_CMD_READ_ACK 0x21 +#define OCI2C_CMD_READ_NACK 0x29 +#define OCI2C_CMD_IACK 0x01 + +#define OCI2C_STAT_IF 0x01 +#define OCI2C_STAT_TIP 0x02 +#define OCI2C_STAT_ARBLOST 0x20 +#define OCI2C_STAT_BUSY 0x40 +#define OCI2C_STAT_NACK 0x80 + +#endif /* _KEMPLD_I2C_H_ */