pwm: ab8500: Implement .get_state()

The registers are readable, so it's possible to implement the
.get_state() callback for this PWM.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

diff --git a/drivers/pwm/pwm-ab8500.c b/drivers/pwm/pwm-ab8500.c
index c5239ee..507ff0d 100644 (file)
--- a/drivers/pwm/pwm-ab8500.c
+++ b/drivers/pwm/pwm-ab8500.c
@@ -136,8 +136,51 @@ static int ab8500_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
        return ret;
 }
 
+static int ab8500_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
+                               struct pwm_state *state)
+{
+       u8 ctrl7, lower_val, higher_val;
+       int ret;
+       struct ab8500_pwm_chip *ab8500 = ab8500_pwm_from_chip(chip);
+       unsigned int div, duty_steps;
+
+       ret = abx500_get_register_interruptible(chip->dev, AB8500_MISC,
+                                               AB8500_PWM_OUT_CTRL7_REG,
+                                               &ctrl7);
+       if (ret)
+               return ret;
+
+       state->polarity = PWM_POLARITY_NORMAL;
+
+       if (!(ctrl7 & 1 << ab8500->hwid)) {
+               state->enabled = false;
+               return 0;
+       }
+
+       ret = abx500_get_register_interruptible(chip->dev, AB8500_MISC,
+                                               AB8500_PWM_OUT_CTRL1_REG + (ab8500->hwid * 2),
+                                               &lower_val);
+       if (ret)
+               return ret;
+
+       ret = abx500_get_register_interruptible(chip->dev, AB8500_MISC,
+                                               AB8500_PWM_OUT_CTRL2_REG + (ab8500->hwid * 2),
+                                               &higher_val);
+       if (ret)
+               return ret;
+
+       div = 32 - ((higher_val & 0xf0) >> 4);
+       duty_steps = ((higher_val & 3) << 8 | lower_val) + 1;
+
+       state->period = DIV64_U64_ROUND_UP((u64)div << 10, AB8500_PWM_CLKRATE);
+       state->duty_cycle = DIV64_U64_ROUND_UP((u64)div * duty_steps, AB8500_PWM_CLKRATE);
+
+       return 0;
+}
+
 static const struct pwm_ops ab8500_pwm_ops = {
        .apply = ab8500_pwm_apply,
+       .get_state = ab8500_pwm_get_state,
        .owner = THIS_MODULE,
 };