i2c: imx-lpi2c: add runtime pm support

Add runtime pm support to dynamically manage the clock to avoid enable/disable
clock in frequently that can improve the i2c bus transfer performance.

And use pm_runtime_force_suspend/resume() instead of lpi2c_imx_suspend/resume().

Signed-off-by: Fugang Duan <fugang.duan@nxp.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

diff --git a/drivers/i2c/busses/i2c-imx-lpi2c.c b/drivers/i2c/busses/i2c-imx-lpi2c.c
index e86801a631206f9d54f6faba57a6050992d5e027..e6da2c7a9a3e60841e7405738f6ea091cc0eea0f 100644 (file)
--- a/drivers/i2c/busses/i2c-imx-lpi2c.c
+++ b/drivers/i2c/busses/i2c-imx-lpi2c.c
@@ -30,6 +30,7 @@
 #include <linux/of_device.h>
 #include <linux/pinctrl/consumer.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
 
@@ -90,6 +91,8 @@
 #define FAST_PLUS_MAX_BITRATE  3400000
 #define HIGHSPEED_MAX_BITRATE  5000000
 
+#define I2C_PM_TIMEOUT         10 /* ms */
+
 enum lpi2c_imx_mode {
        STANDARD,       /* 100+Kbps */
        FAST,           /* 400+Kbps */
@@ -274,8 +277,8 @@ static int lpi2c_imx_master_enable(struct lpi2c_imx_struct *lpi2c_imx)
        unsigned int temp;
        int ret;
 
-       ret = clk_enable(lpi2c_imx->clk);
-       if (ret)
+       ret = pm_runtime_get_sync(lpi2c_imx->adapter.dev.parent);
+       if (ret < 0)
                return ret;
 
        temp = MCR_RST;
@@ -284,7 +287,7 @@ static int lpi2c_imx_master_enable(struct lpi2c_imx_struct *lpi2c_imx)
 
        ret = lpi2c_imx_config(lpi2c_imx);
        if (ret)
-               goto clk_disable;
+               goto rpm_put;
 
        temp = readl(lpi2c_imx->base + LPI2C_MCR);
        temp |= MCR_MEN;
@@ -292,8 +295,9 @@ static int lpi2c_imx_master_enable(struct lpi2c_imx_struct *lpi2c_imx)
 
        return 0;
 
-clk_disable:
-       clk_disable(lpi2c_imx->clk);
+rpm_put:
+       pm_runtime_mark_last_busy(lpi2c_imx->adapter.dev.parent);
+       pm_runtime_put_autosuspend(lpi2c_imx->adapter.dev.parent);
 
        return ret;
 }
@@ -306,7 +310,8 @@ static int lpi2c_imx_master_disable(struct lpi2c_imx_struct *lpi2c_imx)
        temp &= ~MCR_MEN;
        writel(temp, lpi2c_imx->base + LPI2C_MCR);
 
-       clk_disable(lpi2c_imx->clk);
+       pm_runtime_mark_last_busy(lpi2c_imx->adapter.dev.parent);
+       pm_runtime_put_autosuspend(lpi2c_imx->adapter.dev.parent);
 
        return 0;
 }
@@ -606,22 +611,31 @@ static int lpi2c_imx_probe(struct platform_device *pdev)
                return ret;
        }
 
+       pm_runtime_set_autosuspend_delay(&pdev->dev, I2C_PM_TIMEOUT);
+       pm_runtime_use_autosuspend(&pdev->dev);
+       pm_runtime_get_noresume(&pdev->dev);
+       pm_runtime_set_active(&pdev->dev);
+       pm_runtime_enable(&pdev->dev);
+
        temp = readl(lpi2c_imx->base + LPI2C_PARAM);
        lpi2c_imx->txfifosize = 1 << (temp & 0x0f);
        lpi2c_imx->rxfifosize = 1 << ((temp >> 8) & 0x0f);
 
-       clk_disable(lpi2c_imx->clk);
-
        ret = i2c_add_adapter(&lpi2c_imx->adapter);
        if (ret)
-               goto clk_unprepare;
+               goto rpm_disable;
+
+       pm_runtime_mark_last_busy(&pdev->dev);
+       pm_runtime_put_autosuspend(&pdev->dev);
 
        dev_info(&lpi2c_imx->adapter.dev, "LPI2C adapter registered\n");
 
        return 0;
 
-clk_unprepare:
-       clk_unprepare(lpi2c_imx->clk);
+rpm_disable:
+       pm_runtime_put(&pdev->dev);
+       pm_runtime_disable(&pdev->dev);
+       pm_runtime_dont_use_autosuspend(&pdev->dev);
 
        return ret;
 }
@@ -632,28 +646,48 @@ static int lpi2c_imx_remove(struct platform_device *pdev)
 
        i2c_del_adapter(&lpi2c_imx->adapter);
 
-       clk_unprepare(lpi2c_imx->clk);
+       pm_runtime_disable(&pdev->dev);
+       pm_runtime_dont_use_autosuspend(&pdev->dev);
 
        return 0;
 }
 
 #ifdef CONFIG_PM_SLEEP
-static int lpi2c_imx_suspend(struct device *dev)
+static int lpi2c_runtime_suspend(struct device *dev)
 {
+       struct lpi2c_imx_struct *lpi2c_imx = dev_get_drvdata(dev);
+
+       clk_disable_unprepare(lpi2c_imx->clk);
        pinctrl_pm_select_sleep_state(dev);
 
        return 0;
 }
 
-static int lpi2c_imx_resume(struct device *dev)
+static int lpi2c_runtime_resume(struct device *dev)
 {
+       struct lpi2c_imx_struct *lpi2c_imx = dev_get_drvdata(dev);
+       int ret;
+
        pinctrl_pm_select_default_state(dev);
+       ret = clk_prepare_enable(lpi2c_imx->clk);
+       if (ret) {
+               dev_err(dev, "failed to enable I2C clock, ret=%d\n", ret);
+               return ret;
+       }
 
        return 0;
 }
-#endif
 
-static SIMPLE_DEV_PM_OPS(imx_lpi2c_pm, lpi2c_imx_suspend, lpi2c_imx_resume);
+static const struct dev_pm_ops lpi2c_pm_ops = {
+       SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+                                     pm_runtime_force_resume)
+       SET_RUNTIME_PM_OPS(lpi2c_runtime_suspend,
+                          lpi2c_runtime_resume, NULL)
+};
+#define IMX_LPI2C_PM      (&lpi2c_pm_ops)
+#else
+#define IMX_LPI2C_PM      NULL
+#endif
 
 static struct platform_driver lpi2c_imx_driver = {
        .probe = lpi2c_imx_probe,
@@ -661,7 +695,7 @@ static struct platform_driver lpi2c_imx_driver = {
        .driver = {
                .name = DRIVER_NAME,
                .of_match_table = lpi2c_imx_of_match,
-               .pm = &imx_lpi2c_pm,
+               .pm = IMX_LPI2C_PM,
        },
 };