pwm: tegra: Add support for Tegra186

Tegra186 has multiple PWM controllers with only one output instead of
one controller with four outputs in earlier SoC generations.

Add support for Tegra186 and detect the number of PWM outputs using
device tree match data.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

drivers/pwm/pwm-tegra.c

@@ -26,6 +26,7 @@
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/of_device.h>
 #include <linux/pwm.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
@@ -37,6 +38,10 @@
 #define PWM_SCALE_WIDTH	13
 #define PWM_SCALE_SHIFT	0
 
+struct tegra_pwm_soc {
+	unsigned int num_channels;
+};
+
 struct tegra_pwm_chip {
 	struct pwm_chip chip;
 	struct device *dev;
@@ -45,6 +50,8 @@ struct tegra_pwm_chip {
 	struct reset_control*rst;
 
 	void __iomem *regs;
+
+	const struct tegra_pwm_soc *soc;
 };
 
 static inline struct tegra_pwm_chip *to_tegra_pwm_chip(struct pwm_chip *chip)
@@ -177,6 +184,7 @@ static int tegra_pwm_probe(struct platform_device *pdev)
 	if (!pwm)
 		return -ENOMEM;
 
+	pwm->soc = of_device_get_match_data(&pdev->dev);
 	pwm->dev = &pdev->dev;
 
 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -202,7 +210,7 @@ static int tegra_pwm_probe(struct platform_device *pdev)
 	pwm->chip.dev = &pdev->dev;
 	pwm->chip.ops = &tegra_pwm_ops;
 	pwm->chip.base = -1;
-	pwm->chip.npwm = 4;
+	pwm->chip.npwm = pwm->soc->num_channels;
 
 	ret = pwmchip_add(&pwm->chip);
 	if (ret < 0) {
@@ -245,9 +253,17 @@ static int tegra_pwm_remove(struct platform_device *pdev)
 	return pwmchip_remove(&pc->chip);
 }
 
+static const struct tegra_pwm_soc tegra20_pwm_soc = {
+	.num_channels = 4,
+};
+
+static const struct tegra_pwm_soc tegra186_pwm_soc = {
+	.num_channels = 1,
+};
+
 static const struct of_device_id tegra_pwm_of_match[] = {
-	{ .compatible = "nvidia,tegra20-pwm" },
-	{ .compatible = "nvidia,tegra30-pwm" },
+	{ .compatible = "nvidia,tegra20-pwm", .data = &tegra20_pwm_soc },
+	{ .compatible = "nvidia,tegra186-pwm", .data = &tegra186_pwm_soc },
 	{ }
 };