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>

1 files changed, 51 insertions, 17 deletions

diff --git a/drivers/i2c/busses/i2c-imx-lpi2c.c b/drivers/i2c/busses/i2c-imx-lpi2c.c
index e86801a63120..e6da2c7a9a3e 100644
--- 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,
         },
 };