rk3x: i2c: prevent i2c xfer, when i2c shut down.

if rk818 driver's shutdown func called, it should not do i2c transfer.
And rk818's shutdown func is behind of i2c driver's shutdown func.

Change-Id: Iec96ad4640894f604493d8c764a2f98e75397885
Signed-off-by: David Wu <wdc@rock-chips.com>

diff --git a/drivers/i2c/busses/i2c-rockchip.c b/drivers/i2c/busses/i2c-rockchip.c
index 953251121fe52009313a090c34abde4b903fbf83..1745f78ee1ba1279cacab83ba9196cb0194288d4 100644 (file)
--- a/drivers/i2c/busses/i2c-rockchip.c
+++ b/drivers/i2c/busses/i2c-rockchip.c
@@ -92,6 +92,7 @@ struct rockchip_i2c {
        struct device           *dev;
        struct resource         *ioarea;
        struct i2c_adapter      adap;
+       struct mutex            suspend_lock;
 
        unsigned long           scl_rate;
        unsigned long           i2c_rate;
@@ -626,6 +627,7 @@ static int rockchip_i2c_doxfer(struct rockchip_i2c *i2c,
        int msleep_time = 400 * 1000 / i2c->scl_rate;   // ms
        int can_sleep = !(in_atomic() || irqs_disabled());
 
+       mutex_lock(&i2c->suspend_lock);
        if (i2c->suspended) {
                dev_err(i2c->dev, "i2c is suspended\n");
                return -EIO;
@@ -722,6 +724,8 @@ static int rockchip_i2c_doxfer(struct rockchip_i2c *i2c,
        if (error == -EAGAIN)
                i2c_dbg(i2c->dev, "No ack(complete_what: 0x%x), Maybe slave(addr: 0x%04x) not exist or abnormal power-on\n",
                        i2c->complete_what, i2c->addr);
+       mutex_unlock(&i2c->suspend_lock);
+
        return error;
 }
 
@@ -920,6 +924,7 @@ static int rockchip_i2c_probe(struct platform_device *pdev)
        dev_info(&pdev->dev, "%s: Rockchip I2C adapter\n", dev_name(&i2c->adap.dev));
 
        of_i2c_register_devices(&i2c->adap);
+       mutex_init(&i2c->suspend_lock);
 
        return 0;
 }
@@ -933,20 +938,38 @@ static int rockchip_i2c_remove(struct platform_device *pdev)
 {
        struct rockchip_i2c *i2c = platform_get_drvdata(pdev);
 
+       mutex_lock(&i2c->suspend_lock);
+       i2c->suspended = 1;
        i2c_del_adapter(&i2c->adap);
        clk_unprepare(i2c->clk);
+       mutex_unlock(&i2c->suspend_lock);
 
        return 0;
 }
 
+/* rockchip_i2c_shutdown
+ *
+ * called when device is shutdown from the bus
+*/
+static void rockchip_i2c_shutdown(struct platform_device *pdev)
+{
+       struct rockchip_i2c *i2c = platform_get_drvdata(pdev);
+
+       mutex_lock(&i2c->suspend_lock);
+       i2c->suspended = 1;
+       mutex_unlock(&i2c->suspend_lock);
+}
+
 #ifdef CONFIG_PM
 static int rockchip_i2c_suspend_noirq(struct device *dev)
 {
        struct platform_device *pdev = to_platform_device(dev);
        struct rockchip_i2c *i2c = platform_get_drvdata(pdev);
 
+       mutex_lock(&i2c->suspend_lock);
        i2c->suspended = 1;
        pinctrl_pm_select_sleep_state(dev);
+       mutex_unlock(&i2c->suspend_lock);
 
        return 0;
 }
@@ -956,9 +979,11 @@ static int rockchip_i2c_resume_noirq(struct device *dev)
        struct platform_device *pdev = to_platform_device(dev);
        struct rockchip_i2c *i2c = platform_get_drvdata(pdev);
 
+       mutex_lock(&i2c->suspend_lock);
        pinctrl_pm_select_default_state(dev);
        rockchip_i2c_init_hw(i2c, i2c->scl_rate);
        i2c->suspended = 0;
+       mutex_unlock(&i2c->suspend_lock);
 
        return 0;
 }
@@ -982,6 +1007,7 @@ MODULE_DEVICE_TABLE(of, rockchip_i2c_of_match);
 static struct platform_driver rockchip_i2c_driver = {
        .probe          = rockchip_i2c_probe,
        .remove         = rockchip_i2c_remove,
+       .shutdown       = rockchip_i2c_shutdown,
        .driver         = {
                .owner  = THIS_MODULE,
                .name   = "rockchip_i2c",