pwm: Manage owner assignment implicitly for drivers

[J-linux.git] / drivers / pwm / pwm-atmel.c

diff --git a/drivers/pwm/pwm-atmel.c b/drivers/pwm/pwm-atmel.c
index 5f7d286871cf0ec619f6a04806435f7589d5c05a..47bcc8a3bf9d50c48cf80f29e1b03defdb388e4c 100644 (file)
--- a/drivers/pwm/pwm-atmel.c
+++ b/drivers/pwm/pwm-atmel.c
@@ -25,7 +25,6 @@
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/of.h>
-#include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/pwm.h>
 #include <linux/slab.h>
@@ -36,7 +35,7 @@
 #define PWM_SR                 0x0C
 #define PWM_ISR                        0x1C
 /* Bit field in SR */
-#define PWM_SR_ALL_CH_ON       0x0F
+#define PWM_SR_ALL_CH_MASK     0x0F
 
 /* The following register is PWM channel related registers */
 #define PWM_CH_REG_OFFSET      0x200
@@ -403,7 +402,6 @@ static int atmel_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
 static const struct pwm_ops atmel_pwm_ops = {
        .apply = atmel_pwm_apply,
        .get_state = atmel_pwm_get_state,
-       .owner = THIS_MODULE,
 };
 
 static const struct atmel_pwm_data atmel_sam9rl_pwm_data = {
@@ -464,6 +462,42 @@ static const struct of_device_id atmel_pwm_dt_ids[] = {
 };
 MODULE_DEVICE_TABLE(of, atmel_pwm_dt_ids);
 
+static int atmel_pwm_enable_clk_if_on(struct atmel_pwm_chip *atmel_pwm, bool on)
+{
+       unsigned int i, cnt = 0;
+       unsigned long sr;
+       int ret = 0;
+
+       sr = atmel_pwm_readl(atmel_pwm, PWM_SR) & PWM_SR_ALL_CH_MASK;
+       if (!sr)
+               return 0;
+
+       cnt = bitmap_weight(&sr, atmel_pwm->chip.npwm);
+
+       if (!on)
+               goto disable_clk;
+
+       for (i = 0; i < cnt; i++) {
+               ret = clk_enable(atmel_pwm->clk);
+               if (ret) {
+                       dev_err(atmel_pwm->chip.dev,
+                               "failed to enable clock for pwm %pe\n",
+                               ERR_PTR(ret));
+
+                       cnt = i;
+                       goto disable_clk;
+               }
+       }
+
+       return 0;
+
+disable_clk:
+       while (cnt--)
+               clk_disable(atmel_pwm->clk);
+
+       return ret;
+}
+
 static int atmel_pwm_probe(struct platform_device *pdev)
 {
        struct atmel_pwm_chip *atmel_pwm;
@@ -482,51 +516,39 @@ static int atmel_pwm_probe(struct platform_device *pdev)
        if (IS_ERR(atmel_pwm->base))
                return PTR_ERR(atmel_pwm->base);
 
-       atmel_pwm->clk = devm_clk_get(&pdev->dev, NULL);
+       atmel_pwm->clk = devm_clk_get_prepared(&pdev->dev, NULL);
        if (IS_ERR(atmel_pwm->clk))
-               return PTR_ERR(atmel_pwm->clk);
-
-       ret = clk_prepare(atmel_pwm->clk);
-       if (ret) {
-               dev_err(&pdev->dev, "failed to prepare PWM clock\n");
-               return ret;
-       }
+               return dev_err_probe(&pdev->dev, PTR_ERR(atmel_pwm->clk),
+                                    "failed to get prepared PWM clock\n");
 
        atmel_pwm->chip.dev = &pdev->dev;
        atmel_pwm->chip.ops = &atmel_pwm_ops;
        atmel_pwm->chip.npwm = 4;
 
-       ret = pwmchip_add(&atmel_pwm->chip);
+       ret = atmel_pwm_enable_clk_if_on(atmel_pwm, true);
+       if (ret < 0)
+               return ret;
+
+       ret = devm_pwmchip_add(&pdev->dev, &atmel_pwm->chip);
        if (ret < 0) {
-               dev_err(&pdev->dev, "failed to add PWM chip %d\n", ret);
-               goto unprepare_clk;
+               dev_err_probe(&pdev->dev, ret, "failed to add PWM chip\n");
+               goto disable_clk;
        }
 
-       platform_set_drvdata(pdev, atmel_pwm);
+       return 0;
 
-       return ret;
+disable_clk:
+       atmel_pwm_enable_clk_if_on(atmel_pwm, false);
 
-unprepare_clk:
-       clk_unprepare(atmel_pwm->clk);
        return ret;
 }
 
-static void atmel_pwm_remove(struct platform_device *pdev)
-{
-       struct atmel_pwm_chip *atmel_pwm = platform_get_drvdata(pdev);
-
-       pwmchip_remove(&atmel_pwm->chip);
-
-       clk_unprepare(atmel_pwm->clk);
-}
-
 static struct platform_driver atmel_pwm_driver = {
        .driver = {
                .name = "atmel-pwm",
-               .of_match_table = of_match_ptr(atmel_pwm_dt_ids),
+               .of_match_table = atmel_pwm_dt_ids,
        },
        .probe = atmel_pwm_probe,
-       .remove_new = atmel_pwm_remove,
 };
 module_platform_driver(atmel_pwm_driver);