Thread (32 messages) flat view 32 messages, 5 authors, 2014-08-26

[PATCH 2/4] pwm: rockchip: Allow polarity invert on rk3288

From: Thierry Reding <hidden>
Date: 2014-08-19 07:19:05
Also in: linux-devicetree, linux-pwm, lkml

On Mon, Aug 18, 2014 at 10:09:07AM -0700, Doug Anderson wrote:
[...]
quoted hunk ↗ jump to hunk
diff --git a/drivers/pwm/pwm-rockchip.c b/drivers/pwm/pwm-rockchip.c
 #define PWM_LP_DISABLE		(0 << 8)
 
@@ -32,6 +34,7 @@ struct rockchip_pwm_chip {
 	struct pwm_chip chip;
 	struct clk *clk;
 	const struct rockchip_pwm_data *data;
+	enum pwm_polarity polarity;
Why do you need this field? struct pwm_device already has a copy of it.
quoted hunk ↗ jump to hunk
@@ -74,10 +78,14 @@ static void rockchip_pwm_set_enable_v2(struct pwm_chip *chip, bool enable)
 {
 	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
 	u32 enable_conf = PWM_OUTPUT_LEFT | PWM_LP_DISABLE | PWM_ENABLE |
-			  PWM_CONTINUOUS | PWM_DUTY_POSITIVE |
-			  PWM_INACTIVE_NEGATIVE;
+			  PWM_CONTINUOUS;
 	u32 val;
 
+	if (pc->polarity == PWM_POLARITY_INVERSED)
+		enable_conf |= PWM_DUTY_NEGATIVE | PWM_INACTIVE_POSITIVE;
+	else
+		enable_conf |= PWM_DUTY_POSITIVE | PWM_INACTIVE_NEGATIVE;
I have a feeling you're going to answer the above question with: "Because
it's needed here". If so, my reply would be: "Then this function should
take a struct pwm_device instead of struct pwm_chip."
quoted hunk ↗ jump to hunk
@@ -173,6 +195,7 @@ static const struct rockchip_pwm_data pwm_data_v2 = {
 		.ctrl = 0x0c,
 	},
 	.prescaler = 1,
+	.has_invert = 1,
Since has_invert is a boolean, the proper value here would be "true".
quoted hunk ↗ jump to hunk
@@ -228,6 +252,10 @@ static int rockchip_pwm_probe(struct platform_device *pdev)
 	pc->data = id->data;
 	pc->chip.dev = &pdev->dev;
 	pc->chip.ops = &rockchip_pwm_ops;
+	if (pc->data->has_invert) {
+		pc->chip.of_xlate = of_pwm_xlate_with_flags;
+		pc->chip.of_pwm_n_cells = 3;
+	}
 	pc->chip.base = -1;
 	pc->chip.npwm = 1;
I suggest to rewrite the above as follows for readability:

 	pc->data = id->data;
 	pc->chip.dev = &pdev->dev;
 	pc->chip.ops = &rockchip_pwm_ops;
 	pc->chip.base = -1;
 	pc->chip.npwm = 1;
+
+	if (pc->data->has_invert) {
+		pc->chip.of_xlate = of_pwm_xlate_with_flags;
+		pc->chip.of_pwm_n_cells = 3;
+	}

Thierry
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