+ DT maintainers
On Mon, 17 Sep 2018 11:29:49 +0800
Jisheng Zhang <Jisheng.Zhang@xxxxxxxxxxxxx> wrote:
> On some platforms, the sda/scl pins are muxed with gpio functions, so
> they could be used for recovery. Select the gpio/default pin function
> when prepare/unprepare recovery.
>
> Signed-off-by: Jisheng Zhang <Jisheng.Zhang@xxxxxxxxxxxxx>
> ---
> drivers/i2c/busses/i2c-designware-core.h | 3 +++
> drivers/i2c/busses/i2c-designware-master.c | 22 ++++++++++++++++++++++
> 2 files changed, 25 insertions(+)
>
> diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h
> index e367b1af4ab2..01d5f01691a4 100644
> --- a/drivers/i2c/busses/i2c-designware-core.h
> +++ b/drivers/i2c/busses/i2c-designware-core.h
> @@ -271,6 +271,9 @@ struct dw_i2c_dev {
> int (*init)(struct dw_i2c_dev *dev);
> int mode;
> struct i2c_bus_recovery_info rinfo;
> + struct pinctrl *pinctrl;
> + struct pinctrl_state *pins_default;
> + struct pinctrl_state *pins_gpio;
> };
>
> #define ACCESS_SWAP 0x00000001
> diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c
> index 94d94b4a9a0d..384d6630366a 100644
> --- a/drivers/i2c/busses/i2c-designware-master.c
> +++ b/drivers/i2c/busses/i2c-designware-master.c
> @@ -17,6 +17,7 @@
> #include <linux/interrupt.h>
> #include <linux/io.h>
> #include <linux/module.h>
> +#include <linux/pinctrl/consumer.h>
> #include <linux/pm_runtime.h>
> #include <linux/reset.h>
>
> @@ -629,6 +630,9 @@ static void i2c_dw_prepare_recovery(struct i2c_adapter *adap)
> {
> struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
>
> + if (dev->pinctrl && dev->pins_gpio)
> + pinctrl_select_state(dev->pinctrl, dev->pins_gpio);
> +
> i2c_dw_disable(dev);
> reset_control_assert(dev->rst);
> i2c_dw_prepare_clk(dev, false);
> @@ -641,6 +645,9 @@ static void i2c_dw_unprepare_recovery(struct i2c_adapter *adap)
> i2c_dw_prepare_clk(dev, true);
> reset_control_deassert(dev->rst);
> i2c_dw_init_master(dev);
> +
> + if (dev->pinctrl && dev->pins_default)
> + pinctrl_select_state(dev->pinctrl, dev->pins_default);
> }
>
> static int i2c_dw_init_recovery_info(struct dw_i2c_dev *dev)
> @@ -648,6 +655,8 @@ static int i2c_dw_init_recovery_info(struct dw_i2c_dev *dev)
> struct i2c_bus_recovery_info *rinfo = &dev->rinfo;
> struct i2c_adapter *adap = &dev->adapter;
> struct gpio_desc *gpio;
> + struct pinctrl *pinctrl;
> + struct pinctrl_state *s;
> int r;
>
> gpio = devm_gpiod_get(dev->dev, "scl", GPIOD_OUT_HIGH);
> @@ -664,6 +673,19 @@ static int i2c_dw_init_recovery_info(struct dw_i2c_dev *dev)
> return PTR_ERR(gpio);
> rinfo->sda_gpiod = gpio;
>
> + pinctrl = devm_pinctrl_get(dev->dev);
> + if (PTR_ERR(pinctrl) == -EPROBE_DEFER)
> + return -EPROBE_DEFER;
> + if (!IS_ERR_OR_NULL(pinctrl)) {
> + dev->pinctrl = pinctrl;
> + s = pinctrl_lookup_state(pinctrl, PINCTRL_STATE_DEFAULT);
> + if (!IS_ERR_OR_NULL(s))
> + dev->pins_default = s;
> + s = pinctrl_lookup_state(pinctrl, "gpio");
> + if (!IS_ERR_OR_NULL(s))
> + dev->pins_gpio = s;
> + }
> +
> rinfo->recover_bus = i2c_generic_scl_recovery;
> rinfo->prepare_recovery = i2c_dw_prepare_recovery;
> rinfo->unprepare_recovery = i2c_dw_unprepare_recovery;
