i2c: imx-lpi2c: add generic GPIO recovery for LPI2C

This adds i2c bus recovery to the lpi2c driver.

Uses the generic recovery function setting the SCL/SDA pads as
GPIO pins and sending 9 clocks to try and recover the bus.

Signed-off-by: Carlos Song <carlos.song@nxp.com>
Reviewed-by: Clark Wang <xiaoning.wang@nxp.com>
Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>

diff --git a/drivers/i2c/busses/i2c-imx-lpi2c.c b/drivers/i2c/busses/i2c-imx-lpi2c.c
index 678b30e90492ad17294453a5e6c482007946e8f5..6d72e4e126dde6ba07770b20b358ba74dbda78b8 100644 (file)
--- a/drivers/i2c/busses/i2c-imx-lpi2c.c
+++ b/drivers/i2c/busses/i2c-imx-lpi2c.c
@@ -106,6 +106,7 @@ struct lpi2c_imx_struct {
        unsigned int            txfifosize;
        unsigned int            rxfifosize;
        enum lpi2c_imx_mode     mode;
+       struct i2c_bus_recovery_info rinfo;
 };
 
 static void lpi2c_imx_intctrl(struct lpi2c_imx_struct *lpi2c_imx,
@@ -133,6 +134,8 @@ static int lpi2c_imx_bus_busy(struct lpi2c_imx_struct *lpi2c_imx)
 
                if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) {
                        dev_dbg(&lpi2c_imx->adapter.dev, "bus not work\n");
+                       if (lpi2c_imx->adapter.bus_recovery_info)
+                               i2c_recover_bus(&lpi2c_imx->adapter);
                        return -ETIMEDOUT;
                }
                schedule();
@@ -190,6 +193,8 @@ static void lpi2c_imx_stop(struct lpi2c_imx_struct *lpi2c_imx)
 
                if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) {
                        dev_dbg(&lpi2c_imx->adapter.dev, "stop timeout\n");
+                       if (lpi2c_imx->adapter.bus_recovery_info)
+                               i2c_recover_bus(&lpi2c_imx->adapter);
                        break;
                }
                schedule();
@@ -325,6 +330,8 @@ static int lpi2c_imx_txfifo_empty(struct lpi2c_imx_struct *lpi2c_imx)
 
                if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) {
                        dev_dbg(&lpi2c_imx->adapter.dev, "txfifo empty timeout\n");
+                       if (lpi2c_imx->adapter.bus_recovery_info)
+                               i2c_recover_bus(&lpi2c_imx->adapter);
                        return -ETIMEDOUT;
                }
                schedule();
@@ -526,6 +533,20 @@ static irqreturn_t lpi2c_imx_isr(int irq, void *dev_id)
        return IRQ_HANDLED;
 }
 
+static int lpi2c_imx_init_recovery_info(struct lpi2c_imx_struct *lpi2c_imx,
+                                 struct platform_device *pdev)
+{
+       struct i2c_bus_recovery_info *bri = &lpi2c_imx->rinfo;
+
+       bri->pinctrl = devm_pinctrl_get(&pdev->dev);
+       if (IS_ERR(bri->pinctrl))
+               return PTR_ERR(bri->pinctrl);
+
+       lpi2c_imx->adapter.bus_recovery_info = bri;
+
+       return 0;
+}
+
 static u32 lpi2c_imx_func(struct i2c_adapter *adapter)
 {
        return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
@@ -600,6 +621,12 @@ static int lpi2c_imx_probe(struct platform_device *pdev)
        lpi2c_imx->txfifosize = 1 << (temp & 0x0f);
        lpi2c_imx->rxfifosize = 1 << ((temp >> 8) & 0x0f);
 
+       /* Init optional bus recovery function */
+       ret = lpi2c_imx_init_recovery_info(lpi2c_imx, pdev);
+       /* Give it another chance if pinctrl used is not ready yet */
+       if (ret == -EPROBE_DEFER)
+               goto rpm_disable;
+
        ret = i2c_add_adapter(&lpi2c_imx->adapter);
        if (ret)
                goto rpm_disable;