[PATCH v3 3/3] i2c: designware: select gpio/default pin when prepare/unprepare recovery

[Jisheng Zhang]

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.zh...@synaptics.com>
---
 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;
-- 
2.19.0