pwm: Drop useless member .of_pwm_n_cells of struct pwm_chip

Apart from the two of_xlate implementations this member is write-only.
In the of_xlate functions of_pwm_xlate_with_flags() and
of_pwm_single_xlate() it's more sensible to check for args->args_count
because this is what is actually used in the device tree.
Acked-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/53d8c545aa8f79a920358be9e72e382b3981bdc4.1704835845.git.u.kleine-koenig@pengutronix.deSigned-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

drivers/gpu/drm/bridge/ti-sn65dsi86.c

@@ -1591,7 +1591,6 @@ static int ti_sn_pwm_probe(struct auxiliary_device *adev,
 	pdata->pchip.ops = &ti_sn_pwm_ops;
 	pdata->pchip.npwm = 1;
 	pdata->pchip.of_xlate = of_pwm_single_xlate;
-	pdata->pchip.of_pwm_n_cells = 1;
 
 	devm_pm_runtime_enable(&adev->dev);
 

drivers/pwm/core.c

@@ -107,9 +107,6 @@ of_pwm_xlate_with_flags(struct pwm_chip *chip, const struct of_phandle_args *arg
 {
 	struct pwm_device *pwm;
 
-	if (chip->of_pwm_n_cells < 2)
-		return ERR_PTR(-EINVAL);
-
 	/* flags in the third cell are optional */
 	if (args->args_count < 2)
 		return ERR_PTR(-EINVAL);
@@ -124,10 +121,8 @@ of_pwm_xlate_with_flags(struct pwm_chip *chip, const struct of_phandle_args *arg
 	pwm->args.period = args->args[1];
 	pwm->args.polarity = PWM_POLARITY_NORMAL;
 
-	if (chip->of_pwm_n_cells >= 3) {
-		if (args->args_count > 2 && args->args[2] & PWM_POLARITY_INVERTED)
-			pwm->args.polarity = PWM_POLARITY_INVERSED;
-	}
+	if (args->args_count > 2 && args->args[2] & PWM_POLARITY_INVERTED)
+		pwm->args.polarity = PWM_POLARITY_INVERSED;
 
 	return pwm;
 }
@@ -138,9 +133,6 @@ of_pwm_single_xlate(struct pwm_chip *chip, const struct of_phandle_args *args)
 {
 	struct pwm_device *pwm;
 
-	if (chip->of_pwm_n_cells < 1)
-		return ERR_PTR(-EINVAL);
-
 	/* validate that one cell is specified, optionally with flags */
 	if (args->args_count != 1 && args->args_count != 2)
 		return ERR_PTR(-EINVAL);
@@ -164,16 +156,8 @@ static void of_pwmchip_add(struct pwm_chip *chip)
 	if (!chip->dev || !chip->dev->of_node)
 		return;
 
-	if (!chip->of_xlate) {
-		u32 pwm_cells;
-
-		if (of_property_read_u32(chip->dev->of_node, "#pwm-cells",
-					 &pwm_cells))
-			pwm_cells = 2;
-
+	if (!chip->of_xlate)
 		chip->of_xlate = of_pwm_xlate_with_flags;
-		chip->of_pwm_n_cells = pwm_cells;
-	}
 
 	of_node_get(chip->dev->of_node);
 }

drivers/pwm/pwm-clps711x.c

@@ -103,7 +103,6 @@ static int clps711x_pwm_probe(struct platform_device *pdev)
 	priv->chip.dev = &pdev->dev;
 	priv->chip.npwm = 2;
 	priv->chip.of_xlate = clps711x_pwm_xlate;
-	priv->chip.of_pwm_n_cells = 1;
 
 	spin_lock_init(&priv->lock);
 

drivers/pwm/pwm-cros-ec.c

@@ -279,7 +279,6 @@ static int cros_ec_pwm_probe(struct platform_device *pdev)
 	chip->dev = dev;
 	chip->ops = &cros_ec_pwm_ops;
 	chip->of_xlate = cros_ec_pwm_xlate;
-	chip->of_pwm_n_cells = 1;
 
 	if (ec_pwm->use_pwm_type) {
 		chip->npwm = CROS_EC_PWM_DT_COUNT;

drivers/pwm/pwm-pxa.c

@@ -180,10 +180,8 @@ static int pwm_probe(struct platform_device *pdev)
 	pc->chip.ops = &pxa_pwm_ops;
 	pc->chip.npwm = (id->driver_data & HAS_SECONDARY_PWM) ? 2 : 1;
 
-	if (IS_ENABLED(CONFIG_OF)) {
+	if (IS_ENABLED(CONFIG_OF))
 		pc->chip.of_xlate = of_pwm_single_xlate;
-		pc->chip.of_pwm_n_cells = 1;
-	}
 
 	pc->mmio_base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(pc->mmio_base))

include/linux/pwm.h

@@ -271,7 +271,6 @@ struct pwm_ops {
  * @id: unique number of this PWM chip
  * @npwm: number of PWMs controlled by this chip
  * @of_xlate: request a PWM device given a device tree PWM specifier
- * @of_pwm_n_cells: number of cells expected in the device tree PWM specifier
  * @atomic: can the driver's ->apply() be called in atomic context
  * @pwms: array of PWM devices allocated by the framework
  */
@@ -284,7 +283,6 @@ struct pwm_chip {
 
 	struct pwm_device * (*of_xlate)(struct pwm_chip *chip,
 					const struct of_phandle_args *args);
-	unsigned int of_pwm_n_cells;
 	bool atomic;
 
 	/* only used internally by the PWM framework */