pwm: meson: Add the meson_pwm_channel data to struct meson_pwm

Make struct meson_pwm_channel accessible from struct meson_pwm.

PWM core has a limitation: per-channel data can only be set after
pwmchip_add() is called. However, pwmchip_add() internally calls
pwm_ops.get_state(). If pwm_ops.get_state() needs access to the
per-channel data it has to obtain it from struct pwm_chip and struct
pwm_device's hwpwm information.

Add a struct meson_pwm_channel for each PWM channel to struct meson_pwm
so the pwm_ops.get_state() callback can be implemented as it needs
access to the clock from struct meson_pwm_channel.
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

drivers/pwm/pwm-meson.c

@@ -37,6 +37,8 @@
 #define MISC_B_EN		BIT(1)
 #define MISC_A_EN		BIT(0)
 
+#define MESON_NUM_PWMS		2
+
 static const unsigned int mux_reg_shifts[] = {
 	MISC_A_CLK_SEL_SHIFT,
 	MISC_B_CLK_SEL_SHIFT
@@ -62,6 +64,7 @@ struct meson_pwm_data {
 struct meson_pwm {
 	struct pwm_chip chip;
 	const struct meson_pwm_data *data;
+	struct meson_pwm_channel channels[MESON_NUM_PWMS];
 	void __iomem *base;
 	/*
 	 * Protects register (write) access to the REG_MISC_AB register
@@ -444,8 +447,7 @@ static const struct of_device_id meson_pwm_matches[] = {
 };
 MODULE_DEVICE_TABLE(of, meson_pwm_matches);
 
-static int meson_pwm_init_channels(struct meson_pwm *meson,
-				   struct meson_pwm_channel *channels)
+static int meson_pwm_init_channels(struct meson_pwm *meson)
 {
 	struct device *dev = meson->chip.dev;
 	struct clk_init_data init;
@@ -454,7 +456,7 @@ static int meson_pwm_init_channels(struct meson_pwm *meson,
 	int err;
 
 	for (i = 0; i < meson->chip.npwm; i++) {
-		struct meson_pwm_channel *channel = &channels[i];
+		struct meson_pwm_channel *channel = &meson->channels[i];
 
 		snprintf(name, sizeof(name), "%s#mux%u", dev_name(dev), i);
 
@@ -489,18 +491,16 @@ static int meson_pwm_init_channels(struct meson_pwm *meson,
 	return 0;
 }
 
-static void meson_pwm_add_channels(struct meson_pwm *meson,
-				   struct meson_pwm_channel *channels)
+static void meson_pwm_add_channels(struct meson_pwm *meson)
 {
 	unsigned int i;
 
 	for (i = 0; i < meson->chip.npwm; i++)
-		pwm_set_chip_data(&meson->chip.pwms[i], &channels[i]);
+		pwm_set_chip_data(&meson->chip.pwms[i], &meson->channels[i]);
 }
 
 static int meson_pwm_probe(struct platform_device *pdev)
 {
-	struct meson_pwm_channel *channels;
 	struct meson_pwm *meson;
 	struct resource *regs;
 	int err;
@@ -518,18 +518,13 @@ static int meson_pwm_probe(struct platform_device *pdev)
 	meson->chip.dev = &pdev->dev;
 	meson->chip.ops = &meson_pwm_ops;
 	meson->chip.base = -1;
-	meson->chip.npwm = 2;
+	meson->chip.npwm = MESON_NUM_PWMS;
 	meson->chip.of_xlate = of_pwm_xlate_with_flags;
 	meson->chip.of_pwm_n_cells = 3;
 
 	meson->data = of_device_get_match_data(&pdev->dev);
 
-	channels = devm_kcalloc(&pdev->dev, meson->chip.npwm,
-				sizeof(*channels), GFP_KERNEL);
-	if (!channels)
-		return -ENOMEM;
-
-	err = meson_pwm_init_channels(meson, channels);
+	err = meson_pwm_init_channels(meson);
 	if (err < 0)
 		return err;
 
@@ -539,7 +534,7 @@ static int meson_pwm_probe(struct platform_device *pdev)
 		return err;
 	}
 
-	meson_pwm_add_channels(meson, channels);
+	meson_pwm_add_channels(meson);
 
 	platform_set_drvdata(pdev, meson);