1 files changed, 50 insertions, 51 deletions

diff --git a/drivers/pwm/pwm-mxs.c b/drivers/pwm/pwm-mxs.c
index b14376b47ac8..f2e57fcf8f8b 100644
--- a/drivers/pwm/pwm-mxs.c
+++ b/drivers/pwm/pwm-mxs.c
@@ -25,12 +25,16 @@
 #define  PERIOD_PERIOD(p)	((p) & 0xffff)
 #define  PERIOD_PERIOD_MAX	0x10000
 #define  PERIOD_ACTIVE_HIGH	(3 << 16)
+#define  PERIOD_ACTIVE_LOW	(2 << 16)
+#define  PERIOD_INACTIVE_HIGH	(3 << 18)
 #define  PERIOD_INACTIVE_LOW	(2 << 18)
+#define  PERIOD_POLARITY_NORMAL	(PERIOD_ACTIVE_HIGH | PERIOD_INACTIVE_LOW)
+#define  PERIOD_POLARITY_INVERSE	(PERIOD_ACTIVE_LOW | PERIOD_INACTIVE_HIGH)
 #define  PERIOD_CDIV(div)	(((div) & 0x7) << 20)
 #define  PERIOD_CDIV_MAX	8
 
-static const unsigned int cdiv[PERIOD_CDIV_MAX] = {
-	1, 2, 4, 8, 16, 64, 256, 1024
+static const u8 cdiv_shift[PERIOD_CDIV_MAX] = {
+	0, 1, 2, 3, 4, 6, 8, 10
 };
 
 struct mxs_pwm_chip {
@@ -41,19 +45,34 @@ struct mxs_pwm_chip {
 
 #define to_mxs_pwm_chip(_chip) container_of(_chip, struct mxs_pwm_chip, chip)
 
-static int mxs_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
-			  int duty_ns, int period_ns)
+static int mxs_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+			 const struct pwm_state *state)
 {
 	struct mxs_pwm_chip *mxs = to_mxs_pwm_chip(chip);
 	int ret, div = 0;
 	unsigned int period_cycles, duty_cycles;
 	unsigned long rate;
 	unsigned long long c;
+	unsigned int pol_bits;
+
+	/*
+	 * If the PWM channel is disabled, make sure to turn on the
+	 * clock before calling clk_get_rate() and writing to the
+	 * registers. Otherwise, just keep it enabled.
+	 */
+	if (!pwm_is_enabled(pwm)) {
+		ret = clk_prepare_enable(mxs->clk);
+		if (ret)
+			return ret;
+	}
+
+	if (!state->enabled && pwm_is_enabled(pwm))
+		writel(1 << pwm->hwpwm, mxs->base + PWM_CTRL + CLR);
 
 	rate = clk_get_rate(mxs->clk);
 	while (1) {
-		c = rate / cdiv[div];
-		c = c * period_ns;
+		c = rate >> cdiv_shift[div];
+		c = c * state->period;
 		do_div(c, 1000000000);
 		if (c < PERIOD_PERIOD_MAX)
 			break;
@@ -63,62 +82,40 @@ static int mxs_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	}
 
 	period_cycles = c;
-	c *= duty_ns;
-	do_div(c, period_ns);
+	c *= state->duty_cycle;
+	do_div(c, state->period);
 	duty_cycles = c;
 
 	/*
-	 * If the PWM channel is disabled, make sure to turn on the clock
-	 * before writing the register. Otherwise, keep it enabled.
+	 * The data sheet the says registers must be written to in
+	 * this order (ACTIVEn, then PERIODn). Also, the new settings
+	 * only take effect at the beginning of a new period, avoiding
+	 * glitches.
 	 */
-	if (!pwm_is_enabled(pwm)) {
-		ret = clk_prepare_enable(mxs->clk);
-		if (ret)
-			return ret;
-	}
 
+	pol_bits = state->polarity == PWM_POLARITY_NORMAL ?
+		PERIOD_POLARITY_NORMAL : PERIOD_POLARITY_INVERSE;
 	writel(duty_cycles << 16,
-			mxs->base + PWM_ACTIVE0 + pwm->hwpwm * 0x20);
-	writel(PERIOD_PERIOD(period_cycles) | PERIOD_ACTIVE_HIGH |
-	       PERIOD_INACTIVE_LOW | PERIOD_CDIV(div),
-			mxs->base + PWM_PERIOD0 + pwm->hwpwm * 0x20);
-
-	/*
-	 * If the PWM is not enabled, turn the clock off again to save power.
-	 */
-	if (!pwm_is_enabled(pwm))
+	       mxs->base + PWM_ACTIVE0 + pwm->hwpwm * 0x20);
+	writel(PERIOD_PERIOD(period_cycles) | pol_bits | PERIOD_CDIV(div),
+	       mxs->base + PWM_PERIOD0 + pwm->hwpwm * 0x20);
+
+	if (state->enabled) {
+		if (!pwm_is_enabled(pwm)) {
+			/*
+			 * The clock was enabled above. Just enable
+			 * the channel in the control register.
+			 */
+			writel(1 << pwm->hwpwm, mxs->base + PWM_CTRL + SET);
+		}
+	} else {
 		clk_disable_unprepare(mxs->clk);
-
-	return 0;
-}
-
-static int mxs_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
-{
-	struct mxs_pwm_chip *mxs = to_mxs_pwm_chip(chip);
-	int ret;
-
-	ret = clk_prepare_enable(mxs->clk);
-	if (ret)
-		return ret;
-
-	writel(1 << pwm->hwpwm, mxs->base + PWM_CTRL + SET);
-
+	}
 	return 0;
 }
 
-static void mxs_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
-{
-	struct mxs_pwm_chip *mxs = to_mxs_pwm_chip(chip);
-
-	writel(1 << pwm->hwpwm, mxs->base + PWM_CTRL + CLR);
-
-	clk_disable_unprepare(mxs->clk);
-}
-
 static const struct pwm_ops mxs_pwm_ops = {
-	.config = mxs_pwm_config,
-	.enable = mxs_pwm_enable,
-	.disable = mxs_pwm_disable,
+	.apply = mxs_pwm_apply,
 	.owner = THIS_MODULE,
 };
 
@@ -142,6 +139,8 @@ static int mxs_pwm_probe(struct platform_device *pdev)
 
 	mxs->chip.dev = &pdev->dev;
 	mxs->chip.ops = &mxs_pwm_ops;
+	mxs->chip.of_xlate = of_pwm_xlate_with_flags;
+	mxs->chip.of_pwm_n_cells = 3;
 	mxs->chip.base = -1;
 
 	ret = of_property_read_u32(np, "fsl,pwm-number", &mxs->chip.npwm);