pwm: Changes for v4.1-rc1

Not much has been happening in PWM land lately, so this contains mostly
 minor fixes that didn't seem urgent enough for a late pull-request last
 cycle.
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Merge tag 'pwm/for-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm

Pull pwm changes from Thierry Reding:
 "Not much has been happening in PWM land lately, so this contains
  mostly minor fixes that didn't seem urgent enough for a late
  pull-request last cycle"

* tag 'pwm/for-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm:
  pwm: Remove __init initializer for pwm_add_table()
  pwm: samsung: Fix output race on disabling
  pwm: mxs: Fix period divider computation
  pwm: atmel-hlcdc: Add errata handling for sama5d4
  pwm: pca9685: Constify struct regmap_config
  pwm: imx-pwm: add explicit compatible strings and required clock properties

Documentation/devicetree/bindings/pwm/imx-pwm.txt

@@ -1,10 +1,17 @@
 Freescale i.MX PWM controller
 
 Required properties:
-- compatible: should be "fsl,<soc>-pwm"
+- compatible : should be "fsl,<soc>-pwm" and one of the following
+   compatible strings:
+  - "fsl,imx1-pwm" for PWM compatible with the one integrated on i.MX1
+  - "fsl,imx27-pwm" for PWM compatible with the one integrated on i.MX27
 - reg: physical base address and length of the controller's registers
 - #pwm-cells: should be 2. See pwm.txt in this directory for a description of
   the cells format.
+- clocks : Clock specifiers for both ipg and per clocks.
+- clock-names : Clock names should include both "ipg" and "per"
+See the clock consumer binding,
+	Documentation/devicetree/bindings/clock/clock-bindings.txt
 - interrupts: The interrupt for the pwm controller
 
 Example:
@@ -13,5 +20,8 @@ pwm1: pwm@53fb4000 {
 	#pwm-cells = <2>;
 	compatible = "fsl,imx53-pwm", "fsl,imx27-pwm";
 	reg = <0x53fb4000 0x4000>;
+	clocks = <&clks IMX5_CLK_PWM1_IPG_GATE>,
+		 <&clks IMX5_CLK_PWM1_HF_GATE>;
+	clock-names = "ipg", "per";
 	interrupts = <61>;
 };

drivers/pwm/core.c

@@ -573,7 +573,7 @@ EXPORT_SYMBOL_GPL(of_pwm_get);
  * @table: array of consumers to register
  * @num: number of consumers in table
  */
-void __init pwm_add_table(struct pwm_lookup *table, size_t num)
+void pwm_add_table(struct pwm_lookup *table, size_t num)
 {
 	mutex_lock(&pwm_lookup_lock);
 

drivers/pwm/pwm-atmel-hlcdc.c

@@ -225,6 +225,10 @@ static const struct of_device_id atmel_hlcdc_dt_ids[] = {
 		.compatible = "atmel,sama5d3-hlcdc",
 		.data = &atmel_hlcdc_pwm_sama5d3_errata,
 	},
+	{
+		.compatible = "atmel,sama5d4-hlcdc",
+		.data = &atmel_hlcdc_pwm_sama5d3_errata,
+	},
 	{ /* sentinel */ },
 };
 

drivers/pwm/pwm-mxs.c

@@ -35,6 +35,10 @@
 #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
+};
+
 struct mxs_pwm_chip {
 	struct pwm_chip chip;
 	struct clk *clk;
@@ -54,13 +58,13 @@ static int mxs_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 
 	rate = clk_get_rate(mxs->clk);
 	while (1) {
-		c = rate / (1 << div);
+		c = rate / cdiv[div];
 		c = c * period_ns;
 		do_div(c, 1000000000);
 		if (c < PERIOD_PERIOD_MAX)
 			break;
 		div++;
-		if (div > PERIOD_CDIV_MAX)
+		if (div >= PERIOD_CDIV_MAX)
 			return -EINVAL;
 	}
 

drivers/pwm/pwm-pca9685.c

@@ -202,7 +202,7 @@ static const struct pwm_ops pca9685_pwm_ops = {
 	.owner = THIS_MODULE,
 };
 
-static struct regmap_config pca9685_regmap_i2c_config = {
+static const struct regmap_config pca9685_regmap_i2c_config = {
 	.reg_bits = 8,
 	.val_bits = 8,
 	.max_register = PCA9685_NUMREGS,

drivers/pwm/pwm-samsung.c

@@ -269,12 +269,31 @@ static void pwm_samsung_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 	spin_unlock_irqrestore(&samsung_pwm_lock, flags);
 }
 
+static void pwm_samsung_manual_update(struct samsung_pwm_chip *chip,
+				      struct pwm_device *pwm)
+{
+	unsigned int tcon_chan = to_tcon_channel(pwm->hwpwm);
+	u32 tcon;
+	unsigned long flags;
+
+	spin_lock_irqsave(&samsung_pwm_lock, flags);
+
+	tcon = readl(chip->base + REG_TCON);
+	tcon |= TCON_MANUALUPDATE(tcon_chan);
+	writel(tcon, chip->base + REG_TCON);
+
+	tcon &= ~TCON_MANUALUPDATE(tcon_chan);
+	writel(tcon, chip->base + REG_TCON);
+
+	spin_unlock_irqrestore(&samsung_pwm_lock, flags);
+}
+
 static int pwm_samsung_config(struct pwm_chip *chip, struct pwm_device *pwm,
 			      int duty_ns, int period_ns)
 {
 	struct samsung_pwm_chip *our_chip = to_samsung_pwm_chip(chip);
 	struct samsung_pwm_channel *chan = pwm_get_chip_data(pwm);
-	u32 tin_ns = chan->tin_ns, tcnt, tcmp;
+	u32 tin_ns = chan->tin_ns, tcnt, tcmp, oldtcmp;
 
 	/*
 	 * We currently avoid using 64bit arithmetic by using the
@@ -288,6 +307,7 @@ static int pwm_samsung_config(struct pwm_chip *chip, struct pwm_device *pwm,
 		return 0;
 
 	tcnt = readl(our_chip->base + REG_TCNTB(pwm->hwpwm));
+	oldtcmp = readl(our_chip->base + REG_TCMPB(pwm->hwpwm));
 
 	/* We need tick count for calculation, not last tick. */
 	++tcnt;
@@ -335,6 +355,16 @@ static int pwm_samsung_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	writel(tcnt, our_chip->base + REG_TCNTB(pwm->hwpwm));
 	writel(tcmp, our_chip->base + REG_TCMPB(pwm->hwpwm));
 
+	/*
+	 * In case the PWM is currently at 100% duty cycle, force a manual
+	 * update to prevent the signal staying high if the PWM is disabled
+	 * shortly afer this update (before it autoreloaded the new values).
+	 */
+	if (oldtcmp == (u32) -1) {
+		dev_dbg(our_chip->chip.dev, "Forcing manual update");
+		pwm_samsung_manual_update(our_chip, pwm);
+	}
+
 	chan->period_ns = period_ns;
 	chan->tin_ns = tin_ns;
 	chan->duty_ns = duty_ns;