From 93e0dfb2c52f9cb7a7899156475b4e7b0bee7de3 Mon Sep 17 00:00:00 2001 From: Alexandre Belloni Date: Tue, 30 May 2017 21:32:07 +0200 Subject: pwm: sun4i: Improve hardware read out Implement .get_state instead of only reading the polarity at probe time. This allows to get the proper state, period and duty cycle. Signed-off-by: Alexandre Belloni Reviewed-by: Chen-Yu Tsai Acked-by: Maxime Ripard Signed-off-by: Thierry Reding --- drivers/pwm/pwm-sun4i.c | 65 ++++++++++++++++++++++++++++++++++--------------- 1 file changed, 46 insertions(+), 19 deletions(-) diff --git a/drivers/pwm/pwm-sun4i.c b/drivers/pwm/pwm-sun4i.c index 1284ffa05921..175a69245a8a 100644 --- a/drivers/pwm/pwm-sun4i.c +++ b/drivers/pwm/pwm-sun4i.c @@ -44,6 +44,10 @@ #define PWM_DTY_MASK GENMASK(15, 0) +#define PWM_REG_PRD(reg) ((((reg) >> 16) & PWM_PRD_MASK) + 1) +#define PWM_REG_DTY(reg) ((reg) & PWM_DTY_MASK) +#define PWM_REG_PRESCAL(reg, chan) (((reg) >> ((chan) * PWMCH_OFFSET)) & PWM_PRESCAL_MASK) + #define BIT_CH(bit, chan) ((bit) << ((chan) * PWMCH_OFFSET)) static const u32 prescaler_table[] = { @@ -96,6 +100,46 @@ static inline void sun4i_pwm_writel(struct sun4i_pwm_chip *chip, writel(val, chip->base + offset); } +static void sun4i_pwm_get_state(struct pwm_chip *chip, + struct pwm_device *pwm, + struct pwm_state *state) +{ + struct sun4i_pwm_chip *sun4i_pwm = to_sun4i_pwm_chip(chip); + u64 clk_rate, tmp; + u32 val; + unsigned int prescaler; + + clk_rate = clk_get_rate(sun4i_pwm->clk); + + val = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG); + + if ((val == PWM_PRESCAL_MASK) && sun4i_pwm->data->has_prescaler_bypass) + prescaler = 1; + else + prescaler = prescaler_table[PWM_REG_PRESCAL(val, pwm->hwpwm)]; + + if (prescaler == 0) + return; + + if (val & BIT_CH(PWM_ACT_STATE, pwm->hwpwm)) + state->polarity = PWM_POLARITY_NORMAL; + else + state->polarity = PWM_POLARITY_INVERSED; + + if (val & BIT_CH(PWM_CLK_GATING | PWM_EN, pwm->hwpwm)) + state->enabled = true; + else + state->enabled = false; + + val = sun4i_pwm_readl(sun4i_pwm, PWM_CH_PRD(pwm->hwpwm)); + + tmp = prescaler * NSEC_PER_SEC * PWM_REG_DTY(val); + state->duty_cycle = DIV_ROUND_CLOSEST_ULL(tmp, clk_rate); + + tmp = prescaler * NSEC_PER_SEC * PWM_REG_PRD(val); + state->period = DIV_ROUND_CLOSEST_ULL(tmp, clk_rate); +} + static int sun4i_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, int duty_ns, int period_ns) { @@ -257,6 +301,7 @@ static const struct pwm_ops sun4i_pwm_ops = { .set_polarity = sun4i_pwm_set_polarity, .enable = sun4i_pwm_enable, .disable = sun4i_pwm_disable, + .get_state = sun4i_pwm_get_state, .owner = THIS_MODULE, }; @@ -316,8 +361,7 @@ static int sun4i_pwm_probe(struct platform_device *pdev) { struct sun4i_pwm_chip *pwm; struct resource *res; - u32 val; - int i, ret; + int ret; const struct of_device_id *match; match = of_match_device(sun4i_pwm_dt_ids, &pdev->dev); @@ -353,24 +397,7 @@ static int sun4i_pwm_probe(struct platform_device *pdev) platform_set_drvdata(pdev, pwm); - ret = clk_prepare_enable(pwm->clk); - if (ret) { - dev_err(&pdev->dev, "failed to enable PWM clock\n"); - goto clk_error; - } - - val = sun4i_pwm_readl(pwm, PWM_CTRL_REG); - for (i = 0; i < pwm->chip.npwm; i++) - if (!(val & BIT_CH(PWM_ACT_STATE, i))) - pwm_set_polarity(&pwm->chip.pwms[i], - PWM_POLARITY_INVERSED); - clk_disable_unprepare(pwm->clk); - return 0; - -clk_error: - pwmchip_remove(&pwm->chip); - return ret; } static int sun4i_pwm_remove(struct platform_device *pdev) -- cgit