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,
 };