On Thu, Oct 04, 2012 at 04:34:54PM +0530, Viresh Kumar wrote:
> 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@xxxxxxxxxx>
> ---
> V5->V6:
> - removed sda_gpio_flags
>
> drivers/i2c/busses/i2c-designware-core.c | 7 ++++-
> drivers/i2c/busses/i2c-designware-platdrv.c | 38 ++++++++++++++++++++++--
> include/linux/i2c/i2c-designware.h | 46 +++++++++++++++++++++++++++++
> 3 files changed, 88 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 cbba7db..9b7c9bf 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);
> + }
> +
This should be in the core?
> 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..afa0df9 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 +145,45 @@ 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;
It is probably easier to define the whole bri structure in the platform
and simply pass it on here? Hmm, now devicetree also comes to my mind.
Will think about that a little, too, but main implementation should be
left for someone needing that.
> +
> + if (!pdata->skip_sda_polling)
> + recovery_info->sda_gpio = pdata->sda_gpio;
> +
> + 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 +206,8 @@ 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..522dec0
> --- /dev/null
> +++ b/include/linux/i2c/i2c-designware.h
> @@ -0,0 +1,46 @@
> +/*
> + * 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.
> + */
> +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;
> +};
> +
> +#endif /* I2C_DESIGNWARE_H */
> --
> 1.7.12.rc2.18.g61b472e
>
>
--
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Industrial Linux Solutions | http://www.pengutronix.de/ |
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