[PATCH v5 23/46] pwm: rockchip: add support for atomic update
Boris Brezillon
boris.brezillon at free-electrons.com
Wed Mar 30 13:05:31 PDT 2016
Implement the ->apply() function to add support for atomic update.
Signed-off-by: Boris Brezillon <boris.brezillon at free-electrons.com>
Tested-by: Heiko Stuebner <heiko at sntech.de>
---
drivers/pwm/pwm-rockchip.c | 63 ++++++++++++++++++++++++++++------------------
1 file changed, 39 insertions(+), 24 deletions(-)
diff --git a/drivers/pwm/pwm-rockchip.c b/drivers/pwm/pwm-rockchip.c
index 5c7e79c..ed27740 100644
--- a/drivers/pwm/pwm-rockchip.c
+++ b/drivers/pwm/pwm-rockchip.c
@@ -50,7 +50,8 @@ struct rockchip_pwm_data {
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 *pstate);
};
@@ -61,7 +62,8 @@ 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 +93,15 @@ 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;
@@ -168,7 +171,6 @@ 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);
@@ -185,15 +187,8 @@ static int rockchip_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
do_div(div, pc->data->prescaler * NSEC_PER_SEC);
duty = div;
- 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;
}
@@ -211,43 +206,63 @@ static int rockchip_pwm_set_polarity(struct pwm_chip *chip,
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;
+ }
- pc->data->set_enable(chip, pwm, false);
+ if (state->enabled != enabled)
+ pc->data->set_enable(chip, pwm, state->enabled,
+ state->polarity);
+ /*
+ * 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,
+ .apply = rockchip_pwm_apply,
.set_polarity = rockchip_pwm_set_polarity,
- .enable = rockchip_pwm_enable,
- .disable = rockchip_pwm_disable,
.owner = THIS_MODULE,
};
--
2.5.0
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