diff options
| -rw-r--r-- | drivers/pwm/pwm-imx.c | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c index 7a4907b73d7c..6cd3b72fbbc1 100644 --- a/drivers/pwm/pwm-imx.c +++ b/drivers/pwm/pwm-imx.c @@ -83,6 +83,9 @@ #define MX3_PWM_SWR_LOOP 5 +/* PWMPR register value of 0xffff has the same effect as 0xfffe */ +#define MX3_PWMPR_MAX 0xfffe + struct imx_chip { struct clk *clk_per; @@ -93,6 +96,55 @@ struct imx_chip { #define to_imx_chip(chip) container_of(chip, struct imx_chip, chip) +static void imx_pwm_get_state(struct pwm_chip *chip, + struct pwm_device *pwm, struct pwm_state *state) +{ + struct imx_chip *imx = to_imx_chip(chip); + u32 period, prescaler, pwm_clk, ret, val; + u64 tmp; + + val = readl(imx->mmio_base + MX3_PWMCR); + + if (val & MX3_PWMCR_EN) { + state->enabled = true; + ret = clk_prepare_enable(imx->clk_per); + if (ret) + return; + } else { + state->enabled = false; + } + + switch (FIELD_GET(MX3_PWMCR_POUTC, val)) { + case MX3_PWMCR_POUTC_NORMAL: + state->polarity = PWM_POLARITY_NORMAL; + break; + case MX3_PWMCR_POUTC_INVERTED: + state->polarity = PWM_POLARITY_INVERSED; + break; + default: + dev_warn(chip->dev, "can't set polarity, output disconnected"); + } + + prescaler = MX3_PWMCR_PRESCALER_GET(val); + pwm_clk = clk_get_rate(imx->clk_per); + pwm_clk = DIV_ROUND_CLOSEST_ULL(pwm_clk, prescaler); + val = readl(imx->mmio_base + MX3_PWMPR); + period = val >= MX3_PWMPR_MAX ? MX3_PWMPR_MAX : val; + + /* PWMOUT (Hz) = PWMCLK / (PWMPR + 2) */ + tmp = NSEC_PER_SEC * (u64)(period + 2); + state->period = DIV_ROUND_CLOSEST_ULL(tmp, pwm_clk); + + /* PWMSAR can be read only if PWM is enabled */ + if (state->enabled) { + val = readl(imx->mmio_base + MX3_PWMSAR); + tmp = NSEC_PER_SEC * (u64)(val); + state->duty_cycle = DIV_ROUND_CLOSEST_ULL(tmp, pwm_clk); + } else { + state->duty_cycle = 0; + } +} + static int imx_pwm_config_v1(struct pwm_chip *chip, struct pwm_device *pwm, int duty_ns, int period_ns) { @@ -272,6 +324,7 @@ static const struct pwm_ops imx_pwm_ops_v1 = { static const struct pwm_ops imx_pwm_ops_v2 = { .apply = imx_pwm_apply_v2, + .get_state = imx_pwm_get_state, .owner = THIS_MODULE, }; |