From: Viresh Kumar <viresh.kumar@xxxxxx>
Add bus recovery support for designware_i2c controller. It uses generic gpio
based i2c_gpio_recover_bus() routine.
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@xxxxxx>
Signed-off-by: Shiraz Hashim <shiraz.hashim@xxxxxx>
Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxx>
---
drivers/i2c/busses/i2c-designware-core.c | 7 ++++-
drivers/i2c/busses/i2c-designware-platdrv.c | 40 +++++++++++++++++++++--
include/linux/i2c/i2c-designware.h | 49 +++++++++++++++++++++++++++++
3 files changed, 93 insertions(+), 3 deletions(-)
create mode 100644 include/linux/i2c/i2c-designware.h
diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c
index 7b8ebbe..3073178 100644
--- a/drivers/i2c/busses/i2c-designware-core.c
+++ b/drivers/i2c/busses/i2c-designware-core.c
@@ -538,7 +538,12 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
ret = wait_for_completion_interruptible_timeout(&dev->cmd_complete, HZ);
if (ret == 0) {
dev_err(dev->dev, "controller timed out\n");
- i2c_dw_init(dev);
+ if (adap->bus_recovery_info &&
+ adap->bus_recovery_info->recover_bus) {
+ dev_dbg(dev->dev, "try i2c bus recovery\n");
+ adap->bus_recovery_info->recover_bus(adap);
+ }
+
ret = -ETIMEDOUT;
goto done;
} else if (ret < 0)
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index 0506fef..9e8b7e3 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -29,6 +29,7 @@
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/i2c.h>
+#include <linux/i2c/i2c-designware.h>
#include <linux/clk.h>
#include <linux/errno.h>
#include <linux/sched.h>
@@ -45,6 +46,7 @@ static struct i2c_algorithm i2c_dw_algo = {
.master_xfer = i2c_dw_xfer,
.functionality = i2c_dw_func,
};
+
static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
{
return clk_get_rate(dev->clk)/1000;
@@ -55,6 +57,8 @@ static int __devinit dw_i2c_probe(struct platform_device *pdev)
struct dw_i2c_dev *dev;
struct i2c_adapter *adap;
struct resource *mem, *ioarea;
+ struct i2c_dw_pdata *pdata;
+ struct i2c_bus_recovery_info *recovery_info = NULL;
int irq, r;
/* NOTE: driver uses the static register mapping */
@@ -141,17 +145,47 @@ static int __devinit dw_i2c_probe(struct platform_device *pdev)
adap->dev.parent = &pdev->dev;
adap->dev.of_node = pdev->dev.of_node;
+ /* Bus recovery support */
+ pdata = dev_get_platdata(&pdev->dev);
+ if (pdata) {
+ recovery_info = kzalloc(sizeof(*recovery_info), GFP_KERNEL);
+ if (!recovery_info) {
+ adap->bus_recovery_info = NULL;
+ dev_err(&pdev->dev,
+ "failure to allocate memory for bus recovery\n");
+ goto skip_recovery;
+ }
+
+ recovery_info->is_gpio_recovery = true;
+ recovery_info->get_gpio = pdata->get_gpio;
+ recovery_info->put_gpio = pdata->put_gpio;
+ recovery_info->scl_gpio = pdata->scl_gpio;
+ recovery_info->scl_gpio_flags = pdata->scl_gpio_flags;
+ recovery_info->clock_rate_khz = clk_get_rate(dev->clk) / 1000;
+
+ if (!pdata->skip_sda_polling) {
+ recovery_info->sda_gpio = pdata->sda_gpio;
+ recovery_info->sda_gpio_flags = pdata->sda_gpio_flags;
+ }
+
+ adap->bus_recovery_info = recovery_info;
+ } else {
+ adap->bus_recovery_info = NULL;
+ }
+
+skip_recovery:
adap->nr = pdev->id;
r = i2c_add_numbered_adapter(adap);
if (r) {
dev_err(&pdev->dev, "failure adding adapter\n");
- goto err_free_irq;
+ goto err_free_recovery_info;
}
of_i2c_register_devices(adap);
return 0;
-err_free_irq:
+err_free_recovery_info:
+ kfree(recovery_info);
free_irq(dev->irq, dev);
err_iounmap:
iounmap(dev->base);
@@ -174,6 +208,8 @@ static int __devexit dw_i2c_remove(struct platform_device *pdev)
struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
struct resource *mem;
+ kfree(dev->adapter.bus_recovery_info);
+
platform_set_drvdata(pdev, NULL);
i2c_del_adapter(&dev->adapter);
put_device(&pdev->dev);
diff --git a/include/linux/i2c/i2c-designware.h b/include/linux/i2c/i2c-designware.h
new file mode 100644
index 0000000..d60cb61c
--- /dev/null
+++ b/include/linux/i2c/i2c-designware.h
@@ -0,0 +1,49 @@
+/*
+ * Synopsys DesignWare I2C adapter driver's platform data
+ *
+ * Copyright (C) 2012 ST Microelectronics.
+ * Author: Vincenzo Frascino <vincenzo.frascino@xxxxxx>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ */
+#ifndef I2C_DESIGNWARE_H
+#define I2C_DESIGNWARE_H
+
+#include <linux/platform_device.h>
+
+/*
+ * struct i2c_dw_pdata - Designware I2c platform data
+ * @scl_gpio: gpio number of the scl line.
+ * @scl_gpio_flags: flag for gpio_request_one of scl_gpio. 0 implies
+ * GPIOF_OUT_INIT_LOW.
+ * @get_gpio: called before recover_bus() to get padmux configured for scl line
+ * as gpio. Only required if is_gpio_recovery == true
+ * @put_gpio: called after recover_bus() to get padmux configured for scl line
+ * as scl. Only required if is_gpio_recovery == true
+ * @skip_sda_polling: if true, bus recovery will not poll sda line to check if
+ * it became high or not. Below are required only if this is false.
+ * @sda_gpio: gpio number of the sda line.
+ * @sda_gpio_flags: flag for gpio_request_one of sda_gpio. 0 implies
+ * GPIOF_OUT_INIT_LOW.
+ */
+struct i2c_dw_pdata {
+ int scl_gpio;
+ int scl_gpio_flags;
+ int (*get_gpio)(unsigned gpio);
+ void (*put_gpio)(unsigned gpio);
+
+ /* sda polling specific */
+ bool skip_sda_polling;
+ int sda_gpio;
+ int sda_gpio_flags;
+};
+
+#endif /* I2C_DESIGNWARE_H */
--
1.7.12.rc2.18.g61b472e
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