Merge tag 'pwm/for-3.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm

Pull pwm changes from Thierry Reding:
 "The set of changes for this merge window contains two new drivers: one
  for Rockchip SoCs and another for STMicroelectronics STiH4xx SoCs.

  The remainder of the changes are the usual small cleanups such as
  removing redundant OOM messages, signalling that a PWM chip's
  operations can sleep and removing an unneeded dependency"

* tag 'pwm/for-3.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm:
  pwm: rockchip: Added to support for RK3288 SoC
  pwm: rockchip: document RK3288 SoC compatible
  pwm: sti: Remove PWM period table
  pwm: sti: Sync between enable/disable calls
  pwm: sti: Ensure same period values for all channels
  pwm: sti: Fix PWM prescaler handling
  pwm: sti: Supply Device Tree binding documentation for ST's PWM IP
  pwm: sti: Add new driver for ST's PWM IP
  pwm: imx: set can_sleep flag for imx_pwm
  pwm: lpss: remove dependency on clk framework
  pwm: pwm-tipwmss: remove unnecessary OOM messages
  pwm: rockchip: document device tree bindings
  pwm: add Rockchip SoC PWM support

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

@@ -0,0 +1,20 @@
+Rockchip PWM controller
+
+Required properties:
+ - compatible: should be "rockchip,<name>-pwm"
+   "rockchip,rk2928-pwm": found on RK29XX,RK3066 and RK3188 SoCs
+   "rockchip,rk3288-pwm": found on RK3288 SoC
+   "rockchip,vop-pwm": found integrated in VOP on RK3288 SoC
+ - reg: physical base address and length of the controller's registers
+ - clocks: phandle and clock specifier of the PWM reference clock
+ - #pwm-cells: should be 2. See pwm.txt in this directory for a
+   description of the cell format.
+
+Example:
+
+	pwm0: pwm@20030000 {
+		compatible = "rockchip,rk2928-pwm";
+		reg = <0x20030000 0x10>;
+		clocks = <&cru PCLK_PWM01>;
+		#pwm-cells = <2>;
+	};

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

@@ -0,0 +1,41 @@
+STMicroelectronics PWM driver bindings
+--------------------------------------
+
+Required parameters:
+- compatible :		"st,pwm"
+- #pwm-cells : 		Number of cells used to specify a PWM. First cell
+			specifies the per-chip index of the PWM to use and the
+			second cell is the period in nanoseconds - fixed to 2
+			for STiH41x.
+- reg :			Physical base address and length of the controller's
+			registers.
+- pinctrl-names: 	Set to "default".
+- pinctrl-0: 		List of phandles pointing to pin configuration nodes
+			for PWM module.
+			For Pinctrl properties, please refer to [1].
+- clock-names: 		Set to "pwm".
+- clocks: 		phandle of the clock used by the PWM module.
+			For Clk properties, please refer to [2].
+
+Optional properties:
+- st,pwm-num-chan:	Number of available channels. If not passed, the driver
+			will consider single channel by default.
+
+[1] Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
+[2] Documentation/devicetree/bindings/clock/clock-bindings.txt
+
+Example:
+
+pwm1: pwm@fe510000 {
+	compatible = "st,pwm";
+	reg = <0xfe510000 0x68>;
+	#pwm-cells = <2>;
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_pwm1_chan0_default
+		     &pinctrl_pwm1_chan1_default
+		     &pinctrl_pwm1_chan2_default
+		     &pinctrl_pwm1_chan3_default>;
+	clocks = <&clk_sysin>;
+	clock-names = "pwm";
+	st,pwm-num-chan = <4>;
+};

drivers/pwm/Kconfig

@@ -206,6 +206,13 @@ config PWM_RENESAS_TPU
 	  To compile this driver as a module, choose M here: the module
 	  will be called pwm-renesas-tpu.
 
+config PWM_ROCKCHIP
+	tristate "Rockchip PWM support"
+	depends on ARCH_ROCKCHIP
+	help
+	  Generic PWM framework driver for the PWM controller found on
+	  Rockchip SoCs.
+
 config PWM_SAMSUNG
 	tristate "Samsung PWM support"
 	depends on PLAT_SAMSUNG
@@ -226,6 +233,16 @@ config PWM_SPEAR
 	  To compile this driver as a module, choose M here: the module
 	  will be called pwm-spear.
 
+config PWM_STI
+	tristate "STiH4xx PWM support"
+	depends on ARCH_STI
+	depends on OF
+	help
+	  Generic PWM framework driver for STiH4xx SoCs.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called pwm-sti.
+
 config PWM_TEGRA
 	tristate "NVIDIA Tegra PWM support"
 	depends on ARCH_TEGRA

drivers/pwm/Makefile

@@ -18,8 +18,10 @@ obj-$(CONFIG_PWM_PCA9685)	+= pwm-pca9685.o
 obj-$(CONFIG_PWM_PUV3)		+= pwm-puv3.o
 obj-$(CONFIG_PWM_PXA)		+= pwm-pxa.o
 obj-$(CONFIG_PWM_RENESAS_TPU)	+= pwm-renesas-tpu.o
+obj-$(CONFIG_PWM_ROCKCHIP)	+= pwm-rockchip.o
 obj-$(CONFIG_PWM_SAMSUNG)	+= pwm-samsung.o
 obj-$(CONFIG_PWM_SPEAR)		+= pwm-spear.o
+obj-$(CONFIG_PWM_STI)		+= pwm-sti.o
 obj-$(CONFIG_PWM_TEGRA)		+= pwm-tegra.o
 obj-$(CONFIG_PWM_TIECAP)	+= pwm-tiecap.o
 obj-$(CONFIG_PWM_TIEHRPWM)	+= pwm-tiehrpwm.o

drivers/pwm/pwm-imx.c

@@ -262,6 +262,7 @@ static int imx_pwm_probe(struct platform_device *pdev)
 	imx->chip.dev = &pdev->dev;
 	imx->chip.base = -1;
 	imx->chip.npwm = 1;
+	imx->chip.can_sleep = true;
 
 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	imx->mmio_base = devm_ioremap_resource(&pdev->dev, r);

drivers/pwm/pwm-lpss.c

@@ -14,7 +14,6 @@
  */
 
 #include <linux/acpi.h>
-#include <linux/clk.h>
 #include <linux/device.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
@@ -37,7 +36,6 @@ static int pci_drv, plat_drv;	/* So we know which drivers registered */
 struct pwm_lpss_chip {
 	struct pwm_chip chip;
 	void __iomem *regs;
-	struct clk *clk;
 	unsigned long clk_rate;
 };
 
@@ -97,11 +95,6 @@ static int pwm_lpss_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 {
 	struct pwm_lpss_chip *lpwm = to_lpwm(chip);
 	u32 ctrl;
-	int ret;
-
-	ret = clk_prepare_enable(lpwm->clk);
-	if (ret)
-		return ret;
 
 	ctrl = readl(lpwm->regs + PWM);
 	writel(ctrl | PWM_ENABLE, lpwm->regs + PWM);
@@ -116,8 +109,6 @@ static void pwm_lpss_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 
 	ctrl = readl(lpwm->regs + PWM);
 	writel(ctrl & ~PWM_ENABLE, lpwm->regs + PWM);
-
-	clk_disable_unprepare(lpwm->clk);
 }
 
 static const struct pwm_ops pwm_lpss_ops = {
@@ -142,17 +133,7 @@ static struct pwm_lpss_chip *pwm_lpss_probe(struct device *dev,
 	if (IS_ERR(lpwm->regs))
 		return ERR_CAST(lpwm->regs);
 
-	if (info) {
-		lpwm->clk_rate = info->clk_rate;
-	} else {
-		lpwm->clk = devm_clk_get(dev, NULL);
-		if (IS_ERR(lpwm->clk)) {
-			dev_err(dev, "failed to get PWM clock\n");
-			return ERR_CAST(lpwm->clk);
-		}
-		lpwm->clk_rate = clk_get_rate(lpwm->clk);
-	}
-
+	lpwm->clk_rate = info->clk_rate;
 	lpwm->chip.dev = dev;
 	lpwm->chip.ops = &pwm_lpss_ops;
 	lpwm->chip.base = -1;
@@ -221,12 +202,19 @@ static struct pci_driver pwm_lpss_driver_pci = {
 
 static int pwm_lpss_probe_platform(struct platform_device *pdev)
 {
+	const struct pwm_lpss_boardinfo *info;
+	const struct acpi_device_id *id;
 	struct pwm_lpss_chip *lpwm;
 	struct resource *r;
 
+	id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
+	if (!id)
+		return -ENODEV;
+
 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 
-	lpwm = pwm_lpss_probe(&pdev->dev, r, NULL);
+	info = (struct pwm_lpss_boardinfo *)id->driver_data;
+	lpwm = pwm_lpss_probe(&pdev->dev, r, info);
 	if (IS_ERR(lpwm))
 		return PTR_ERR(lpwm);
 
@@ -242,7 +230,7 @@ static int pwm_lpss_remove_platform(struct platform_device *pdev)
 }
 
 static const struct acpi_device_id pwm_lpss_acpi_match[] = {
-	{ "80860F09", 0 },
+	{ "80860F09", (unsigned long)&byt_info },
 	{ },
 };
 MODULE_DEVICE_TABLE(acpi, pwm_lpss_acpi_match);

drivers/pwm/pwm-rockchip.c

@@ -0,0 +1,264 @@
+/*
+ * PWM driver for Rockchip SoCs
+ *
+ * Copyright (C) 2014 Beniamino Galvani <b.galvani@gmail.com>
+ * Copyright (C) 2014 ROCKCHIP, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ */
+
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/time.h>
+
+#define PWM_CTRL_TIMER_EN	(1 << 0)
+#define PWM_CTRL_OUTPUT_EN	(1 << 3)
+
+#define PWM_ENABLE		(1 << 0)
+#define PWM_CONTINUOUS		(1 << 1)
+#define PWM_DUTY_POSITIVE	(1 << 3)
+#define PWM_INACTIVE_NEGATIVE	(0 << 4)
+#define PWM_OUTPUT_LEFT		(0 << 5)
+#define PWM_LP_DISABLE		(0 << 8)
+
+struct rockchip_pwm_chip {
+	struct pwm_chip chip;
+	struct clk *clk;
+	const struct rockchip_pwm_data *data;
+	void __iomem *base;
+};
+
+struct rockchip_pwm_regs {
+	unsigned long duty;
+	unsigned long period;
+	unsigned long cntr;
+	unsigned long ctrl;
+};
+
+struct rockchip_pwm_data {
+	struct rockchip_pwm_regs regs;
+	unsigned int prescaler;
+
+	void (*set_enable)(struct pwm_chip *chip, bool enable);
+};
+
+static inline struct rockchip_pwm_chip *to_rockchip_pwm_chip(struct pwm_chip *c)
+{
+	return container_of(c, struct rockchip_pwm_chip, chip);
+}
+
+static void rockchip_pwm_set_enable_v1(struct pwm_chip *chip, bool enable)
+{
+	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
+	u32 enable_conf = PWM_CTRL_OUTPUT_EN | PWM_CTRL_TIMER_EN;
+	u32 val;
+
+	val = readl_relaxed(pc->base + pc->data->regs.ctrl);
+
+	if (enable)
+		val |= enable_conf;
+	else
+		val &= ~enable_conf;
+
+	writel_relaxed(val, pc->base + pc->data->regs.ctrl);
+}
+
+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;
+	u32 val;
+
+	val = readl_relaxed(pc->base + pc->data->regs.ctrl);
+
+	if (enable)
+		val |= enable_conf;
+	else
+		val &= ~enable_conf;
+
+	writel_relaxed(val, pc->base + pc->data->regs.ctrl);
+}
+
+static int rockchip_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
+			       int duty_ns, int period_ns)
+{
+	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
+	unsigned long period, duty;
+	u64 clk_rate, div;
+	int ret;
+
+	clk_rate = clk_get_rate(pc->clk);
+
+	/*
+	 * Since period and duty cycle registers have a width of 32
+	 * bits, every possible input period can be obtained using the
+	 * default prescaler value for all practical clock rate values.
+	 */
+	div = clk_rate * period_ns;
+	do_div(div, pc->data->prescaler * NSEC_PER_SEC);
+	period = div;
+
+	div = clk_rate * duty_ns;
+	do_div(div, pc->data->prescaler * NSEC_PER_SEC);
+	duty = div;
+
+	ret = clk_enable(pc->clk);
+	if (ret)
+		return ret;
+
+	writel(period, pc->base + pc->data->regs.period);
+	writel(duty, pc->base + pc->data->regs.duty);
+	writel(0, pc->base + pc->data->regs.cntr);
+
+	clk_disable(pc->clk);
+
+	return 0;
+}
+
+static int rockchip_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
+	int ret;
+
+	ret = clk_enable(pc->clk);
+	if (ret)
+		return ret;
+
+	pc->data->set_enable(chip, true);
+
+	return 0;
+}
+
+static void rockchip_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
+
+	pc->data->set_enable(chip, false);
+
+	clk_disable(pc->clk);
+}
+
+static const struct pwm_ops rockchip_pwm_ops = {
+	.config = rockchip_pwm_config,
+	.enable = rockchip_pwm_enable,
+	.disable = rockchip_pwm_disable,
+	.owner = THIS_MODULE,
+};
+
+static const struct rockchip_pwm_data pwm_data_v1 = {
+	.regs = {
+		.duty = 0x04,
+		.period = 0x08,
+		.cntr = 0x00,
+		.ctrl = 0x0c,
+	},
+	.prescaler = 2,
+	.set_enable = rockchip_pwm_set_enable_v1,
+};
+
+static const struct rockchip_pwm_data pwm_data_v2 = {
+	.regs = {
+		.duty = 0x08,
+		.period = 0x04,
+		.cntr = 0x00,
+		.ctrl = 0x0c,
+	},
+	.prescaler = 1,
+	.set_enable = rockchip_pwm_set_enable_v2,
+};
+
+static const struct rockchip_pwm_data pwm_data_vop = {
+	.regs = {
+		.duty = 0x08,
+		.period = 0x04,
+		.cntr = 0x0c,
+		.ctrl = 0x00,
+	},
+	.prescaler = 1,
+	.set_enable = rockchip_pwm_set_enable_v2,
+};
+
+static const struct of_device_id rockchip_pwm_dt_ids[] = {
+	{ .compatible = "rockchip,rk2928-pwm", .data = &pwm_data_v1},
+	{ .compatible = "rockchip,rk3288-pwm", .data = &pwm_data_v2},
+	{ .compatible = "rockchip,vop-pwm", .data = &pwm_data_vop},
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, rockchip_pwm_dt_ids);
+
+static int rockchip_pwm_probe(struct platform_device *pdev)
+{
+	const struct of_device_id *id;
+	struct rockchip_pwm_chip *pc;
+	struct resource *r;
+	int ret;
+
+	id = of_match_device(rockchip_pwm_dt_ids, &pdev->dev);
+	if (!id)
+		return -EINVAL;
+
+	pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
+	if (!pc)
+		return -ENOMEM;
+
+	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	pc->base = devm_ioremap_resource(&pdev->dev, r);
+	if (IS_ERR(pc->base))
+		return PTR_ERR(pc->base);
+
+	pc->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(pc->clk))
+		return PTR_ERR(pc->clk);
+
+	ret = clk_prepare(pc->clk);
+	if (ret)
+		return ret;
+
+	platform_set_drvdata(pdev, pc);
+
+	pc->data = id->data;
+	pc->chip.dev = &pdev->dev;
+	pc->chip.ops = &rockchip_pwm_ops;
+	pc->chip.base = -1;
+	pc->chip.npwm = 1;
+
+	ret = pwmchip_add(&pc->chip);
+	if (ret < 0) {
+		clk_unprepare(pc->clk);
+		dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
+	}
+
+	return ret;
+}
+
+static int rockchip_pwm_remove(struct platform_device *pdev)
+{
+	struct rockchip_pwm_chip *pc = platform_get_drvdata(pdev);
+
+	clk_unprepare(pc->clk);
+
+	return pwmchip_remove(&pc->chip);
+}
+
+static struct platform_driver rockchip_pwm_driver = {
+	.driver = {
+		.name = "rockchip-pwm",
+		.of_match_table = rockchip_pwm_dt_ids,
+	},
+	.probe = rockchip_pwm_probe,
+	.remove = rockchip_pwm_remove,
+};
+module_platform_driver(rockchip_pwm_driver);
+
+MODULE_AUTHOR("Beniamino Galvani <b.galvani@gmail.com>");
+MODULE_DESCRIPTION("Rockchip SoC PWM driver");
+MODULE_LICENSE("GPL v2");

drivers/pwm/pwm-sti.c

@@ -0,0 +1,418 @@
+/*
+ * PWM device driver for ST SoCs.
+ * Author: Ajit Pal Singh <ajitpal.singh@st.com>
+ *
+ * Copyright (C) 2013-2014 STMicroelectronics (R&D) Limited
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/clk.h>
+#include <linux/math64.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/time.h>
+
+#define STI_DS_REG(ch)	(4 * (ch))	/* Channel's Duty Cycle register */
+#define STI_PWMCR	0x50		/* Control/Config register */
+#define STI_INTEN	0x54		/* Interrupt Enable/Disable register */
+#define PWM_PRESCALE_LOW_MASK		0x0f
+#define PWM_PRESCALE_HIGH_MASK		0xf0
+
+/* Regfield IDs */
+enum {
+	PWMCLK_PRESCALE_LOW,
+	PWMCLK_PRESCALE_HIGH,
+	PWM_EN,
+	PWM_INT_EN,
+
+	/* Keep last */
+	MAX_REGFIELDS
+};
+
+struct sti_pwm_compat_data {
+	const struct reg_field *reg_fields;
+	unsigned int num_chan;
+	unsigned int max_pwm_cnt;
+	unsigned int max_prescale;
+};
+
+struct sti_pwm_chip {
+	struct device *dev;
+	struct clk *clk;
+	unsigned long clk_rate;
+	struct regmap *regmap;
+	struct sti_pwm_compat_data *cdata;
+	struct regmap_field *prescale_low;
+	struct regmap_field *prescale_high;
+	struct regmap_field *pwm_en;
+	struct regmap_field *pwm_int_en;
+	struct pwm_chip chip;
+	struct pwm_device *cur;
+	unsigned int en_count;
+	struct mutex sti_pwm_lock; /* To sync between enable/disable calls */
+	void __iomem *mmio;
+};
+
+static const struct reg_field sti_pwm_regfields[MAX_REGFIELDS] = {
+	[PWMCLK_PRESCALE_LOW]	= REG_FIELD(STI_PWMCR, 0, 3),
+	[PWMCLK_PRESCALE_HIGH]	= REG_FIELD(STI_PWMCR, 11, 14),
+	[PWM_EN]		= REG_FIELD(STI_PWMCR, 9, 9),
+	[PWM_INT_EN]		= REG_FIELD(STI_INTEN, 0, 0),
+};
+
+static inline struct sti_pwm_chip *to_sti_pwmchip(struct pwm_chip *chip)
+{
+	return container_of(chip, struct sti_pwm_chip, chip);
+}
+
+/*
+ * Calculate the prescaler value corresponding to the period.
+ */
+static int sti_pwm_get_prescale(struct sti_pwm_chip *pc, unsigned long period,
+				unsigned int *prescale)
+{
+	struct sti_pwm_compat_data *cdata = pc->cdata;
+	unsigned long val;
+	unsigned int ps;
+
+	/*
+	 * prescale = ((period_ns * clk_rate) / (10^9 * (max_pwm_count + 1)) - 1
+	 */
+	val = NSEC_PER_SEC / pc->clk_rate;
+	val *= cdata->max_pwm_cnt + 1;
+
+	if (period % val) {
+		return -EINVAL;
+	} else {
+		ps  = period / val - 1;
+		if (ps > cdata->max_prescale)
+			return -EINVAL;
+	}
+	*prescale = ps;
+
+	return 0;
+}
+
+/* Calculate the number of PWM devices configured with a period. */
+static unsigned int sti_pwm_count_configured(struct pwm_chip *chip)
+{
+	struct pwm_device *pwm;
+	unsigned int ncfg = 0;
+	unsigned int i;
+
+	for (i = 0; i < chip->npwm; i++) {
+		pwm = &chip->pwms[i];
+		if (test_bit(PWMF_REQUESTED, &pwm->flags)) {
+			if (pwm_get_period(pwm))
+				ncfg++;
+		}
+	}
+
+	return ncfg;
+}
+
+/*
+ * For STiH4xx PWM IP, the PWM period is fixed to 256 local clock cycles.
+ * The only way to change the period (apart from changing the PWM input clock)
+ * is to change the PWM clock prescaler.
+ * The prescaler is of 8 bits, so 256 prescaler values and hence
+ * 256 possible period values are supported (for a particular clock rate).
+ * The requested period will be applied only if it matches one of these
+ * 256 values.
+ */
+static int sti_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
+			 int duty_ns, int period_ns)
+{
+	struct sti_pwm_chip *pc = to_sti_pwmchip(chip);
+	struct sti_pwm_compat_data *cdata = pc->cdata;
+	struct pwm_device *cur = pc->cur;
+	struct device *dev = pc->dev;
+	unsigned int prescale = 0, pwmvalx;
+	int ret;
+	unsigned int ncfg;
+	bool period_same = false;
+
+	ncfg = sti_pwm_count_configured(chip);
+	if (ncfg)
+		period_same = (period_ns == pwm_get_period(cur));
+
+	/* Allow configuration changes if one of the
+	 * following conditions satisfy.
+	 * 1. No channels have been configured.
+	 * 2. Only one channel has been configured and the new request
+	 *    is for the same channel.
+	 * 3. Only one channel has been configured and the new request is
+	 *    for a new channel and period of the new channel is same as
+	 *    the current configured period.
+	 * 4. More than one channels are configured and period of the new
+	 *    requestis the same as the current period.
+	 */
+	if (!ncfg ||
+	    ((ncfg == 1) && (pwm->hwpwm == cur->hwpwm)) ||
+	    ((ncfg == 1) && (pwm->hwpwm != cur->hwpwm) && period_same) ||
+	    ((ncfg > 1) && period_same)) {
+		/* Enable clock before writing to PWM registers. */
+		ret = clk_enable(pc->clk);
+		if (ret)
+			return ret;
+
+		if (!period_same) {
+			ret = sti_pwm_get_prescale(pc, period_ns, &prescale);
+			if (ret)
+				goto clk_dis;
+
+			ret =
+			regmap_field_write(pc->prescale_low,
+					   prescale & PWM_PRESCALE_LOW_MASK);
+			if (ret)
+				goto clk_dis;
+
+			ret =
+			regmap_field_write(pc->prescale_high,
+				(prescale & PWM_PRESCALE_HIGH_MASK) >> 4);
+			if (ret)
+				goto clk_dis;
+		}
+
+		/*
+		 * When PWMVal == 0, PWM pulse = 1 local clock cycle.
+		 * When PWMVal == max_pwm_count,
+		 * PWM pulse = (max_pwm_count + 1) local cycles,
+		 * that is continuous pulse: signal never goes low.
+		 */
+		pwmvalx = cdata->max_pwm_cnt * duty_ns / period_ns;
+
+		ret = regmap_write(pc->regmap, STI_DS_REG(pwm->hwpwm), pwmvalx);
+		if (ret)
+			goto clk_dis;
+
+		ret = regmap_field_write(pc->pwm_int_en, 0);
+
+		pc->cur = pwm;
+
+		dev_dbg(dev, "prescale:%u, period:%i, duty:%i, pwmvalx:%u\n",
+			prescale, period_ns, duty_ns, pwmvalx);
+	} else {
+		return -EINVAL;
+	}
+
+clk_dis:
+	clk_disable(pc->clk);
+	return ret;
+}
+
+static int sti_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct sti_pwm_chip *pc = to_sti_pwmchip(chip);
+	struct device *dev = pc->dev;
+	int ret = 0;
+
+	/*
+	 * Since we have a common enable for all PWM channels,
+	 * do not enable if already enabled.
+	 */
+	mutex_lock(&pc->sti_pwm_lock);
+	if (!pc->en_count) {
+		ret = clk_enable(pc->clk);
+		if (ret)
+			goto out;
+
+		ret = regmap_field_write(pc->pwm_en, 1);
+		if (ret) {
+			dev_err(dev, "failed to enable PWM device:%d\n",
+				pwm->hwpwm);
+			goto out;
+		}
+	}
+	pc->en_count++;
+out:
+	mutex_unlock(&pc->sti_pwm_lock);
+	return ret;
+}
+
+static void sti_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct sti_pwm_chip *pc = to_sti_pwmchip(chip);
+
+	mutex_lock(&pc->sti_pwm_lock);
+	if (--pc->en_count) {
+		mutex_unlock(&pc->sti_pwm_lock);
+		return;
+	}
+	regmap_field_write(pc->pwm_en, 0);
+
+	clk_disable(pc->clk);
+	mutex_unlock(&pc->sti_pwm_lock);
+}
+
+static const struct pwm_ops sti_pwm_ops = {
+	.config = sti_pwm_config,
+	.enable = sti_pwm_enable,
+	.disable = sti_pwm_disable,
+	.owner = THIS_MODULE,
+};
+
+static int sti_pwm_probe_dt(struct sti_pwm_chip *pc)
+{
+	struct device *dev = pc->dev;
+	const struct reg_field *reg_fields;
+	struct device_node *np = dev->of_node;
+	struct sti_pwm_compat_data *cdata = pc->cdata;
+	u32 num_chan;
+
+	of_property_read_u32(np, "st,pwm-num-chan", &num_chan);
+	if (num_chan)
+		cdata->num_chan = num_chan;
+
+	reg_fields = cdata->reg_fields;
+
+	pc->prescale_low = devm_regmap_field_alloc(dev, pc->regmap,
+					reg_fields[PWMCLK_PRESCALE_LOW]);
+	if (IS_ERR(pc->prescale_low))
+		return PTR_ERR(pc->prescale_low);
+
+	pc->prescale_high = devm_regmap_field_alloc(dev, pc->regmap,
+					reg_fields[PWMCLK_PRESCALE_HIGH]);
+	if (IS_ERR(pc->prescale_high))
+		return PTR_ERR(pc->prescale_high);
+
+	pc->pwm_en = devm_regmap_field_alloc(dev, pc->regmap,
+					     reg_fields[PWM_EN]);
+	if (IS_ERR(pc->pwm_en))
+		return PTR_ERR(pc->pwm_en);
+
+	pc->pwm_int_en = devm_regmap_field_alloc(dev, pc->regmap,
+						 reg_fields[PWM_INT_EN]);
+	if (IS_ERR(pc->pwm_int_en))
+		return PTR_ERR(pc->pwm_int_en);
+
+	return 0;
+}
+
+static const struct regmap_config sti_pwm_regmap_config = {
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+};
+
+static int sti_pwm_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct sti_pwm_compat_data *cdata;
+	struct sti_pwm_chip *pc;
+	struct resource *res;
+	int ret;
+
+	pc = devm_kzalloc(dev, sizeof(*pc), GFP_KERNEL);
+	if (!pc)
+		return -ENOMEM;
+
+	cdata = devm_kzalloc(dev, sizeof(*cdata), GFP_KERNEL);
+	if (!cdata)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+	pc->mmio = devm_ioremap_resource(dev, res);
+	if (IS_ERR(pc->mmio))
+		return PTR_ERR(pc->mmio);
+
+	pc->regmap = devm_regmap_init_mmio(dev, pc->mmio,
+					   &sti_pwm_regmap_config);
+	if (IS_ERR(pc->regmap))
+		return PTR_ERR(pc->regmap);
+
+	/*
+	 * Setup PWM data with default values: some values could be replaced
+	 * with specific ones provided from Device Tree.
+	 */
+	cdata->reg_fields   = &sti_pwm_regfields[0];
+	cdata->max_prescale = 0xff;
+	cdata->max_pwm_cnt  = 255;
+	cdata->num_chan     = 1;
+
+	pc->cdata = cdata;
+	pc->dev = dev;
+	pc->en_count = 0;
+	mutex_init(&pc->sti_pwm_lock);
+
+	ret = sti_pwm_probe_dt(pc);
+	if (ret)
+		return ret;
+
+	pc->clk = of_clk_get_by_name(dev->of_node, "pwm");
+	if (IS_ERR(pc->clk)) {
+		dev_err(dev, "failed to get PWM clock\n");
+		return PTR_ERR(pc->clk);
+	}
+
+	pc->clk_rate = clk_get_rate(pc->clk);
+	if (!pc->clk_rate) {
+		dev_err(dev, "failed to get clock rate\n");
+		return -EINVAL;
+	}
+
+	ret = clk_prepare(pc->clk);
+	if (ret) {
+		dev_err(dev, "failed to prepare clock\n");
+		return ret;
+	}
+
+	pc->chip.dev = dev;
+	pc->chip.ops = &sti_pwm_ops;
+	pc->chip.base = -1;
+	pc->chip.npwm = pc->cdata->num_chan;
+	pc->chip.can_sleep = true;
+
+	ret = pwmchip_add(&pc->chip);
+	if (ret < 0) {
+		clk_unprepare(pc->clk);
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, pc);
+
+	return 0;
+}
+
+static int sti_pwm_remove(struct platform_device *pdev)
+{
+	struct sti_pwm_chip *pc = platform_get_drvdata(pdev);
+	unsigned int i;
+
+	for (i = 0; i < pc->cdata->num_chan; i++)
+		pwm_disable(&pc->chip.pwms[i]);
+
+	clk_unprepare(pc->clk);
+
+	return pwmchip_remove(&pc->chip);
+}
+
+static const struct of_device_id sti_pwm_of_match[] = {
+	{ .compatible = "st,sti-pwm", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, sti_pwm_of_match);
+
+static struct platform_driver sti_pwm_driver = {
+	.driver = {
+		.name = "sti-pwm",
+		.of_match_table = sti_pwm_of_match,
+	},
+	.probe = sti_pwm_probe,
+	.remove = sti_pwm_remove,
+};
+module_platform_driver(sti_pwm_driver);
+
+MODULE_AUTHOR("Ajit Pal Singh <ajitpal.singh@st.com>");
+MODULE_DESCRIPTION("STMicroelectronics ST PWM driver");
+MODULE_LICENSE("GPL");

drivers/pwm/pwm-tipwmss.c

@@ -62,10 +62,8 @@ static int pwmss_probe(struct platform_device *pdev)
 	struct device_node *node = pdev->dev.of_node;
 
 	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
-	if (!info) {
-		dev_err(&pdev->dev, "failed to allocate memory\n");
+	if (!info)
 		return -ENOMEM;
-	}
 
 	mutex_init(&info->pwmss_lock);