pwm: rockchip: Add support for atomic update

Implement the ->apply() function to add support for atomic update.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Tested-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

diff --git a/drivers/pwm/pwm-rockchip.c b/drivers/pwm/pwm-rockchip.c
index dd8ca8663c2434c1edd5646d4ab90f264c3dc473..ef89df1f7336c77a70c3a4de42b6d71ec96162ba 100644 (file)
--- a/drivers/pwm/pwm-rockchip.c
+++ b/drivers/pwm/pwm-rockchip.c
@@ -47,10 +47,12 @@ struct rockchip_pwm_regs {
 struct rockchip_pwm_data {
        struct rockchip_pwm_regs regs;
        unsigned int prescaler;
+       bool supports_polarity;
        const struct pwm_ops *ops;
 
        void (*set_enable)(struct pwm_chip *chip,
-                          struct pwm_device *pwm, bool enable);
+                          struct pwm_device *pwm, bool enable,
+                          enum pwm_polarity polarity);
        void (*get_state)(struct pwm_chip *chip, struct pwm_device *pwm,
                          struct pwm_state *state);
 };
@@ -61,7 +63,8 @@ static inline struct rockchip_pwm_chip *to_rockchip_pwm_chip(struct pwm_chip *c)
 }
 
 static void rockchip_pwm_set_enable_v1(struct pwm_chip *chip,
-                                      struct pwm_device *pwm, bool enable)
+                                      struct pwm_device *pwm, bool enable,
+                                      enum pwm_polarity polarity)
 {
        struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
        u32 enable_conf = PWM_CTRL_OUTPUT_EN | PWM_CTRL_TIMER_EN;
@@ -91,14 +94,15 @@ static void rockchip_pwm_get_state_v1(struct pwm_chip *chip,
 }
 
 static void rockchip_pwm_set_enable_v2(struct pwm_chip *chip,
-                                      struct pwm_device *pwm, bool enable)
+                                      struct pwm_device *pwm, bool enable,
+                                      enum pwm_polarity polarity)
 {
        struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
        u32 enable_conf = PWM_OUTPUT_LEFT | PWM_LP_DISABLE | PWM_ENABLE |
                          PWM_CONTINUOUS;
        u32 val;
 
-       if (pwm_get_polarity(pwm) == PWM_POLARITY_INVERSED)
+       if (polarity == PWM_POLARITY_INVERSED)
                enable_conf |= PWM_DUTY_NEGATIVE | PWM_INACTIVE_POSITIVE;
        else
                enable_conf |= PWM_DUTY_POSITIVE | PWM_INACTIVE_NEGATIVE;
@@ -166,7 +170,6 @@ static int rockchip_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
        struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
        unsigned long period, duty;
        u64 clk_rate, div;
-       int ret;
 
        clk_rate = clk_get_rate(pc->clk);
 
@@ -182,69 +185,66 @@ static int rockchip_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
        div = clk_rate * duty_ns;
        duty = DIV_ROUND_CLOSEST_ULL(div, pc->data->prescaler * NSEC_PER_SEC);
 
-       ret = clk_enable(pc->clk);
-       if (ret)
-               return ret;
-
        writel(period, pc->base + pc->data->regs.period);
        writel(duty, pc->base + pc->data->regs.duty);
-       writel(0, pc->base + pc->data->regs.cntr);
-
-       clk_disable(pc->clk);
-
-       return 0;
-}
-
-static int rockchip_pwm_set_polarity(struct pwm_chip *chip,
-                                    struct pwm_device *pwm,
-                                    enum pwm_polarity polarity)
-{
-       /*
-        * No action needed here because pwm->polarity will be set by the core
-        * and the core will only change polarity when the PWM is not enabled.
-        * We'll handle things in set_enable().
-        */
 
        return 0;
 }
 
-static int rockchip_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+static int rockchip_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+                             struct pwm_state *state)
 {
        struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
+       struct pwm_state curstate;
+       bool enabled;
        int ret;
 
+       pwm_get_state(pwm, &curstate);
+       enabled = curstate.enabled;
+
        ret = clk_enable(pc->clk);
        if (ret)
                return ret;
 
-       pc->data->set_enable(chip, pwm, true);
+       if (state->polarity != curstate.polarity && enabled) {
+               pc->data->set_enable(chip, pwm, false, state->polarity);
+               enabled = false;
+       }
 
-       return 0;
-}
+       ret = rockchip_pwm_config(chip, pwm, state->duty_cycle, state->period);
+       if (ret) {
+               if (enabled != curstate.enabled)
+                       pc->data->set_enable(chip, pwm, !enabled,
+                                            state->polarity);
 
-static void rockchip_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
-{
-       struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
+               goto out;
+       }
+
+       if (state->enabled != enabled)
+               pc->data->set_enable(chip, pwm, state->enabled,
+                                    state->polarity);
 
-       pc->data->set_enable(chip, pwm, false);
+       /*
+        * Update the state with the real hardware, which can differ a bit
+        * because of period/duty_cycle approximation.
+        */
+       rockchip_pwm_get_state(chip, pwm, state);
 
+out:
        clk_disable(pc->clk);
+
+       return ret;
 }
 
 static const struct pwm_ops rockchip_pwm_ops_v1 = {
        .get_state = rockchip_pwm_get_state,
-       .config = rockchip_pwm_config,
-       .enable = rockchip_pwm_enable,
-       .disable = rockchip_pwm_disable,
+       .apply = rockchip_pwm_apply,
        .owner = THIS_MODULE,
 };
 
 static const struct pwm_ops rockchip_pwm_ops_v2 = {
        .get_state = rockchip_pwm_get_state,
-       .config = rockchip_pwm_config,
-       .set_polarity = rockchip_pwm_set_polarity,
-       .enable = rockchip_pwm_enable,
-       .disable = rockchip_pwm_disable,
+       .apply = rockchip_pwm_apply,
        .owner = THIS_MODULE,
 };
 
@@ -269,6 +269,7 @@ static const struct rockchip_pwm_data pwm_data_v2 = {
                .ctrl = 0x0c,
        },
        .prescaler = 1,
+       .supports_polarity = true,
        .ops = &rockchip_pwm_ops_v2,
        .set_enable = rockchip_pwm_set_enable_v2,
        .get_state = rockchip_pwm_get_state_v2,
@@ -282,6 +283,7 @@ static const struct rockchip_pwm_data pwm_data_vop = {
                .ctrl = 0x00,
        },
        .prescaler = 1,
+       .supports_polarity = true,
        .ops = &rockchip_pwm_ops_v2,
        .set_enable = rockchip_pwm_set_enable_v2,
        .get_state = rockchip_pwm_get_state_v2,
@@ -331,7 +333,7 @@ static int rockchip_pwm_probe(struct platform_device *pdev)
        pc->chip.base = -1;
        pc->chip.npwm = 1;
 
-       if (pc->data->ops->set_polarity) {
+       if (pc->data->supports_polarity) {
                pc->chip.of_xlate = of_pwm_xlate_with_flags;
                pc->chip.of_pwm_n_cells = 3;
        }