Merge tag 'pwm/for-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm

Pull pwm changes from Thierry Reding:
"Mostly bug fixes and clean up. There is a new driver, which is
actually moving a custom PWM driver from drivers/misc.

The majority of the patches are enhancements to the device tree
support in the pwm-backlight driver. Backlights can now additionally
be powered using a regulator and enabled using a GPIO in addition to
just the PWM input"

* tag 'pwm/for-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm: (30 commits)
Documentation/pwm: Update supported SoC name for pwm-samsung
pwm: samsung: Fix kernel warning while unexporting a channel
MAINTAINERS: Move PWM subsystem tree to kernel.org
Documentation/pwm: Fix trivial typos
pwm-backlight: Remove unused variable
pwm_backlight: avoid short blank screen while doing hibernation
pwm-backlight: Fix brightness adjustment
pwm: add ep93xx PWM support
pwm-backlight: Allow for non-increasing brightness levels
pwm-backlight: Add power supply support
pwm-backlight: Use new enable_gpio field
unicore32: Initialize PWM backlight enable_gpio field
ARM: shmobile: Initialize PWM backlight enable_gpio field
ARM: SAMSUNG: Initialize PWM backlight enable_gpio field
ARM: pxa: Initialize PWM backlight enable_gpio field
ARM: OMAP: Initialize PWM backlight enable_gpio field
pwm-backlight: Add optional enable GPIO
pwm-backlight: Track enable state
pwm-backlight: Refactor backlight power on/off
pwm-backlight: Improve readability
...

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

···
     samsung,s5pc100-pwm - for 32-bit timers present on S5PC100, S5PV210,
 			  Exynos4210 rev0 SoCs
     samsung,exynos4210-pwm - for 32-bit timers present on Exynos4210,
-                          Exynos4x12 and Exynos5250 SoCs
+                          Exynos4x12, Exynos5250 and Exynos5420 SoCs
 - reg: base address and size of register area
 - interrupts: list of timer interrupts (one interrupt per timer, starting at
   timer 0)

Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt

···
       last value in the array represents a 100% duty cycle (brightest).
   - default-brightness-level: the default brightness level (index into the
       array defined by the "brightness-levels" property)
+  - power-supply: regulator for supply voltage
 
 Optional properties:
   - pwm-names: a list of names for the PWM devices specified in the
                "pwms" property (see PWM binding[0])
+  - enable-gpios: contains a single GPIO specifier for the GPIO which enables
+                  and disables the backlight (see GPIO binding[1])
 
 [0]: Documentation/devicetree/bindings/pwm/pwm.txt
+[1]: Documentation/devicetree/bindings/gpio/gpio.txt
 
 Example:
 
···
 
 		brightness-levels = <0 4 8 16 32 64 128 255>;
 		default-brightness-level = <6>;
+
+		power-supply = <&vdd_bl_reg>;
+		enable-gpios = <&gpio 58 0>;
 	};

Documentation/pwm.txt

···
 device or a consumer name. pwm_put() is used to free the PWM device. Managed
 variants of these functions, devm_pwm_get() and devm_pwm_put(), also exist.
 
-After being requested a PWM has to be configured using:
+After being requested, a PWM has to be configured using:
 
 int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns);
 
···
 A new PWM controller/chip can be added using pwmchip_add() and removed
 again with pwmchip_remove(). pwmchip_add() takes a filled in struct
 pwm_chip as argument which provides a description of the PWM chip, the
-number of PWM devices provider by the chip and the chip-specific
+number of PWM devices provided by the chip and the chip-specific
 implementation of the supported PWM operations to the framework.
 
 Locking

MAINTAINERS

···
 M:	Thierry Reding <[e-mail]>
 L:	[e-mail]
 S:	Maintained
-W:	http://gitorious.org/linux-pwm
-T:	git git://gitorious.org/linux-pwm/linux-pwm.git
+T:	git git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm.git
 F:	Documentation/pwm.txt
 F:	Documentation/devicetree/bindings/pwm/
 F:	include/linux/pwm.h

arch/arm/mach-pxa/cm-x300.c

···
 	.max_brightness	= 100,
 	.dft_brightness	= 100,
 	.pwm_period_ns	= 10000,
+	.enable_gpio	= -1,
 };
 
 static struct platform_device cm_x300_backlight_device = {

arch/arm/mach-pxa/colibri-pxa270-income.c

···
 	.max_brightness	= 0x3ff,
 	.dft_brightness	= 0x1ff,
 	.pwm_period_ns	= 1000000,
+	.enable_gpio	= -1,
 };
 
 static struct platform_device income_backlight = {

arch/arm/mach-pxa/ezx.c

···
 	.max_brightness	= 1023,
 	.dft_brightness	= 1023,
 	.pwm_period_ns	= 78770,
+	.enable_gpio	= -1,
 };
 
 static struct platform_device ezx_backlight_device = {

arch/arm/mach-pxa/hx4700.c

···
 	.max_brightness = 200,
 	.dft_brightness = 100,
 	.pwm_period_ns  = 30923,
+	.enable_gpio    = -1,
 };
 
 static struct platform_device backlight = {

arch/arm/mach-pxa/lpd270.c

···
 	.max_brightness	= 1,
 	.dft_brightness	= 1,
 	.pwm_period_ns	= 78770,
+	.enable_gpio	= -1,
 };
 
 static struct platform_device lpd270_backlight_device = {

arch/arm/mach-pxa/magician.c

···
 	.max_brightness = 272,
 	.dft_brightness = 100,
 	.pwm_period_ns  = 30923,
+	.enable_gpio    = -1,
 	.init           = magician_backlight_init,
 	.notify         = magician_backlight_notify,
 	.exit           = magician_backlight_exit,

arch/arm/mach-pxa/mainstone.c

···
 	.max_brightness	= 1023,
 	.dft_brightness	= 1023,
 	.pwm_period_ns	= 78770,
+	.enable_gpio	= -1,
 };
 
 static struct platform_device mainstone_backlight_device = {

arch/arm/mach-pxa/mioa701.c

···
 	.max_brightness	= 100,
 	.dft_brightness	= 50,
 	.pwm_period_ns	= 4000 * 1024,	/* Fl = 250kHz */
+	.enable_gpio	= -1,
 };
 
 /*

arch/arm/mach-pxa/palm27x.c

···
 	.max_brightness	= 0xfe,
 	.dft_brightness	= 0x7e,
 	.pwm_period_ns	= 3500 * 1024,
+	.enable_gpio	= -1,
 	.init		= palm27x_backlight_init,
 	.notify		= palm27x_backlight_notify,
 	.exit		= palm27x_backlight_exit,

arch/arm/mach-pxa/palmtc.c

···
  * Backlight
  ******************************************************************************/
 #if defined(CONFIG_BACKLIGHT_PWM) || defined(CONFIG_BACKLIGHT_PWM_MODULE)
-static int palmtc_backlight_init(struct device *dev)
-{
-	int ret;
-
-	ret = gpio_request(GPIO_NR_PALMTC_BL_POWER, "BL POWER");
-	if (ret)
-		goto err;
-	ret = gpio_direction_output(GPIO_NR_PALMTC_BL_POWER, 1);
-	if (ret)
-		goto err2;
-
-	return 0;
-
-err2:
-	gpio_free(GPIO_NR_PALMTC_BL_POWER);
-err:
-	return ret;
-}
-
-static int palmtc_backlight_notify(struct device *dev, int brightness)
-{
-	/* backlight is on when GPIO16 AF0 is high */
-	gpio_set_value(GPIO_NR_PALMTC_BL_POWER, brightness);
-	return brightness;
-}
-
-static void palmtc_backlight_exit(struct device *dev)
-{
-	gpio_free(GPIO_NR_PALMTC_BL_POWER);
-}
-
 static struct platform_pwm_backlight_data palmtc_backlight_data = {
 	.pwm_id		= 1,
 	.max_brightness	= PALMTC_MAX_INTENSITY,
 	.dft_brightness	= PALMTC_MAX_INTENSITY,
 	.pwm_period_ns	= PALMTC_PERIOD_NS,
-	.init		= palmtc_backlight_init,
-	.notify		= palmtc_backlight_notify,
-	.exit		= palmtc_backlight_exit,
+	.enable_gpio	= GPIO_NR_PALMTC_BL_POWER,
 };
 
 static struct platform_device palmtc_backlight = {

arch/arm/mach-pxa/palmte2.c

···
 	.max_brightness	= PALMTE2_MAX_INTENSITY,
 	.dft_brightness	= PALMTE2_MAX_INTENSITY,
 	.pwm_period_ns	= PALMTE2_PERIOD_NS,
+	.enable_gpio	= -1,
 	.init		= palmte2_backlight_init,
 	.notify		= palmte2_backlight_notify,
 	.exit		= palmte2_backlight_exit,

arch/arm/mach-pxa/pcm990-baseboard.c

···
 	.max_brightness	= 1023,
 	.dft_brightness	= 1023,
 	.pwm_period_ns	= 78770,
+	.enable_gpio	= -1,
 };
 
 static struct platform_device pcm990_backlight_device = {

arch/arm/mach-pxa/raumfeld.c

···
 	.dft_brightness	= 100,
 	/* 10000 ns = 10 ms ^= 100 kHz */
 	.pwm_period_ns	= 10000,
+	.enable_gpio	= -1,
 };
 
 static struct platform_device raumfeld_pwm_backlight_device = {

arch/arm/mach-pxa/tavorevb.c

···
 		.max_brightness	= 100,
 		.dft_brightness	= 100,
 		.pwm_period_ns	= 100000,
+		.enable_gpio	= -1,
 	},
 	[1] = {
 		/* secondary backlight */
···
 		.max_brightness	= 100,
 		.dft_brightness	= 100,
 		.pwm_period_ns	= 100000,
+		.enable_gpio	= -1,
 	},
 };
 

arch/arm/mach-pxa/viper.c

···
 	.max_brightness	= 100,
 	.dft_brightness	= 100,
 	.pwm_period_ns	= 1000000,
+	.enable_gpio	= -1,
 	.init		= viper_backlight_init,
 	.notify		= viper_backlight_notify,
 	.exit		= viper_backlight_exit,

arch/arm/mach-pxa/z2.c

···
 		.max_brightness	= 1023,
 		.dft_brightness	= 0,
 		.pwm_period_ns	= 1260320,
+		.enable_gpio	= -1,
 	},
 	[1] = {
 		/* LCD Backlight */
···
 		.max_brightness	= 1023,
 		.dft_brightness	= 512,
 		.pwm_period_ns	= 1260320,
+		.enable_gpio	= -1,
 	},
 };
 

arch/arm/mach-pxa/zylonite.c

···
 	.max_brightness	= 100,
 	.dft_brightness	= 100,
 	.pwm_period_ns	= 10000,
+	.enable_gpio	= -1,
 };
 
 static struct platform_device zylonite_backlight_device = {

arch/arm/mach-s3c24xx/mach-h1940.c

···
 	.dft_brightness = 50,
 	/* tcnt = 0x31 */
 	.pwm_period_ns  = 36296,
+	.enable_gpio    = -1,
 	.init           = h1940_backlight_init,
 	.notify		= h1940_backlight_notify,
 	.exit           = h1940_backlight_exit,

arch/arm/mach-s3c24xx/mach-rx1950.c

···
 	.max_brightness = 24,
 	.dft_brightness = 4,
 	.pwm_period_ns = 48000,
+	.enable_gpio = -1,
 	.init = rx1950_backlight_init,
 	.notify = rx1950_backlight_notify,
 	.exit = rx1950_backlight_exit,

arch/arm/mach-s3c64xx/mach-crag6410.c

···
 	.max_brightness	= 1000,
 	.dft_brightness	= 600,
 	.pwm_period_ns	= 100000,	/* about 1kHz */
+	.enable_gpio	= -1,
 };
 
 static struct platform_device crag6410_backlight_device = {

arch/arm/mach-s3c64xx/mach-hmt.c

···
 	.max_brightness	= 100 * 256,
 	.dft_brightness	= 40 * 256,
 	.pwm_period_ns	= 1000000000 / (100 * 256 * 20),
+	.enable_gpio	= -1,
 	.init		= hmt_bl_init,
 	.notify		= hmt_bl_notify,
 	.exit		= hmt_bl_exit,

arch/arm/mach-s3c64xx/mach-smartq.c

···
 	.max_brightness	= 1000,
 	.dft_brightness	= 600,
 	.pwm_period_ns	= 1000000000 / (1000 * 20),
+	.enable_gpio	= -1,
 	.init		= smartq_bl_init,
 };
 

arch/arm/mach-s3c64xx/mach-smdk6410.c

···
 
 static struct platform_pwm_backlight_data smdk6410_bl_data = {
 	.pwm_id = 1,
+	.enable_gpio = -1,
 };
 
 static struct s3c_hsotg_plat smdk6410_hsotg_pdata;

arch/arm/mach-s5p64x0/mach-smdk6440.c

···
 
 static struct platform_pwm_backlight_data smdk6440_bl_data = {
 	.pwm_id = 1,
+	.enable_gpio = -1,
 };
 
 static void __init smdk6440_map_io(void)

arch/arm/mach-s5p64x0/mach-smdk6450.c

···
 
 static struct platform_pwm_backlight_data smdk6450_bl_data = {
 	.pwm_id = 1,
+	.enable_gpio = -1,
 };
 
 static void __init smdk6450_map_io(void)

arch/arm/mach-s5pc100/mach-smdkc100.c

···
 
 static struct platform_pwm_backlight_data smdkc100_bl_data = {
 	.pwm_id = 0,
+	.enable_gpio = -1,
 };
 
 static void __init smdkc100_map_io(void)

arch/arm/mach-s5pv210/mach-smdkv210.c

···
 static struct platform_pwm_backlight_data smdkv210_bl_data = {
 	.pwm_id = 3,
 	.pwm_period_ns = 1000,
+	.enable_gpio = -1,
 };
 
 static void __init smdkv210_map_io(void)

arch/arm/mach-shmobile/board-armadillo800eva.c

···
 	.max_brightness = 255,
 	.dft_brightness = 255,
 	.pwm_period_ns = 33333, /* 30kHz */
+	.enable_gpio = -1,
 };
 
 static struct platform_device pwm_backlight_device = {

arch/arm/plat-samsung/dev-backlight.c

···
 		.max_brightness = 255,
 		.dft_brightness = 255,
 		.pwm_period_ns  = 78770,
+		.enable_gpio    = -1,
 		.init           = samsung_bl_init,
 		.exit           = samsung_bl_exit,
 	},
···
 		samsung_bl_data->lth_brightness = bl_data->lth_brightness;
 	if (bl_data->pwm_period_ns)
 		samsung_bl_data->pwm_period_ns = bl_data->pwm_period_ns;
+	if (bl_data->enable_gpio >= 0)
+		samsung_bl_data->enable_gpio = bl_data->enable_gpio;
+	if (bl_data->enable_gpio_flags)
+		samsung_bl_data->enable_gpio_flags = bl_data->enable_gpio_flags;
 	if (bl_data->init)
 		samsung_bl_data->init = bl_data->init;
 	if (bl_data->notify)

arch/unicore32/kernel/puv3-nb0916.c

···
 	.max_brightness	= 100,
 	.dft_brightness	= 100,
 	.pwm_period_ns	= 70 * 1024,
+	.enable_gpio	= -1,
 };
 
 static struct gpio_keys_button nb0916_gpio_keys[] = {

drivers/misc/Kconfig

···
 	  This driver provides support for the Honeywell HMC6352 compass,
 	  providing configuration and heading data via sysfs.
 
-config EP93XX_PWM
-	tristate "EP93xx PWM support"
-	depends on ARCH_EP93XX
-	help
-	  This option enables device driver support for the PWM channels
-	  on the Cirrus EP93xx processors.  The EP9307 chip only has one
-	  PWM channel all the others have two, the second channel is an
-	  alternate function of the EGPIO14 pin.  A sysfs interface is
-	  provided to control the PWM channels.
-
-	  To compile this driver as a module, choose M here: the module will
-	  be called ep93xx_pwm.
-
 config DS1682
 	tristate "Dallas DS1682 Total Elapsed Time Recorder with Alarm"
 	depends on I2C

drivers/misc/Makefile

···
 obj-$(CONFIG_ISL29003)		+= isl29003.o
 obj-$(CONFIG_ISL29020)		+= isl29020.o
 obj-$(CONFIG_SENSORS_TSL2550)	+= tsl2550.o
-obj-$(CONFIG_EP93XX_PWM)	+= ep93xx_pwm.o
 obj-$(CONFIG_DS1682)		+= ds1682.o
 obj-$(CONFIG_TI_DAC7512)	+= ti_dac7512.o
 obj-$(CONFIG_C2PORT)		+= c2port/

drivers/misc/ep93xx_pwm.c

···
-/*
- *  Simple PWM driver for EP93XX
- *
- *	(c) Copyright 2009  Matthieu Crapet <[e-mail]>
- *	(c) Copyright 2009  H Hartley Sweeten <[e-mail]>
- *
- *	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.
- *
- *  EP9307 has only one channel:
- *    - PWMOUT
- *
- *  EP9301/02/12/15 have two channels:
- *    - PWMOUT
- *    - PWMOUT1 (alternate function for EGPIO14)
- */
-
-#include <linux/module.h>
-#include <linux/platform_device.h>
-#include <linux/slab.h>
-#include <linux/clk.h>
-#include <linux/err.h>
-#include <linux/io.h>
-
-#include <mach/platform.h>
-
-#define EP93XX_PWMx_TERM_COUNT	0x00
-#define EP93XX_PWMx_DUTY_CYCLE	0x04
-#define EP93XX_PWMx_ENABLE	0x08
-#define EP93XX_PWMx_INVERT	0x0C
-
-#define EP93XX_PWM_MAX_COUNT	0xFFFF
-
-struct ep93xx_pwm {
-	void __iomem	*mmio_base;
-	struct clk	*clk;
-	u32		duty_percent;
-};
-
-/*
- * /sys/devices/platform/ep93xx-pwm.N
- *   /min_freq      read-only   minimum pwm output frequency
- *   /max_req       read-only   maximum pwm output frequency
- *   /freq          read-write  pwm output frequency (0 = disable output)
- *   /duty_percent  read-write  pwm duty cycle percent (1..99)
- *   /invert        read-write  invert pwm output
- */
-
-static ssize_t ep93xx_pwm_get_min_freq(struct device *dev,
-		struct device_attribute *attr, char *buf)
-{
-	struct platform_device *pdev = to_platform_device(dev);
-	struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
-	unsigned long rate = clk_get_rate(pwm->clk);
-
-	return sprintf(buf, "%ld\n", rate / (EP93XX_PWM_MAX_COUNT + 1));
-}
-
-static ssize_t ep93xx_pwm_get_max_freq(struct device *dev,
-		struct device_attribute *attr, char *buf)
-{
-	struct platform_device *pdev = to_platform_device(dev);
-	struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
-	unsigned long rate = clk_get_rate(pwm->clk);
-
-	return sprintf(buf, "%ld\n", rate / 2);
-}
-
-static ssize_t ep93xx_pwm_get_freq(struct device *dev,
-		struct device_attribute *attr, char *buf)
-{
-	struct platform_device *pdev = to_platform_device(dev);
-	struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
-
-	if (readl(pwm->mmio_base + EP93XX_PWMx_ENABLE) & 0x1) {
-		unsigned long rate = clk_get_rate(pwm->clk);
-		u16 term = readl(pwm->mmio_base + EP93XX_PWMx_TERM_COUNT);
-
-		return sprintf(buf, "%ld\n", rate / (term + 1));
-	} else {
-		return sprintf(buf, "disabled\n");
-	}
-}
-
-static ssize_t ep93xx_pwm_set_freq(struct device *dev,
-		struct device_attribute *attr, const char *buf, size_t count)
-{
-	struct platform_device *pdev = to_platform_device(dev);
-	struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
-	long val;
-	int err;
-
-	err = kstrtol(buf, 10, &val);
-	if (err)
-		return -EINVAL;
-
-	if (val == 0) {
-		writel(0x0, pwm->mmio_base + EP93XX_PWMx_ENABLE);
-	} else if (val <= (clk_get_rate(pwm->clk) / 2)) {
-		u32 term, duty;
-
-		val = (clk_get_rate(pwm->clk) / val) - 1;
-		if (val > EP93XX_PWM_MAX_COUNT)
-			val = EP93XX_PWM_MAX_COUNT;
-		if (val < 1)
-			val = 1;
-
-		term = readl(pwm->mmio_base + EP93XX_PWMx_TERM_COUNT);
-		duty = ((val + 1) * pwm->duty_percent / 100) - 1;
-
-		/* If pwm is running, order is important */
-		if (val > term) {
-			writel(val, pwm->mmio_base + EP93XX_PWMx_TERM_COUNT);
-			writel(duty, pwm->mmio_base + EP93XX_PWMx_DUTY_CYCLE);
-		} else {
-			writel(duty, pwm->mmio_base + EP93XX_PWMx_DUTY_CYCLE);
-			writel(val, pwm->mmio_base + EP93XX_PWMx_TERM_COUNT);
-		}
-
-		if (!readl(pwm->mmio_base + EP93XX_PWMx_ENABLE) & 0x1)
-			writel(0x1, pwm->mmio_base + EP93XX_PWMx_ENABLE);
-	} else {
-		return -EINVAL;
-	}
-
-	return count;
-}
-
-static ssize_t ep93xx_pwm_get_duty_percent(struct device *dev,
-		struct device_attribute *attr, char *buf)
-{
-	struct platform_device *pdev = to_platform_device(dev);
-	struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
-
-	return sprintf(buf, "%d\n", pwm->duty_percent);
-}
-
-static ssize_t ep93xx_pwm_set_duty_percent(struct device *dev,
-		struct device_attribute *attr, const char *buf, size_t count)
-{
-	struct platform_device *pdev = to_platform_device(dev);
-	struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
-	long val;
-	int err;
-
-	err = kstrtol(buf, 10, &val);
-	if (err)
-		return -EINVAL;
-
-	if (val > 0 && val < 100) {
-		u32 term = readl(pwm->mmio_base + EP93XX_PWMx_TERM_COUNT);
-		u32 duty = ((term + 1) * val / 100) - 1;
-
-		writel(duty, pwm->mmio_base + EP93XX_PWMx_DUTY_CYCLE);
-		pwm->duty_percent = val;
-		return count;
-	}
-
-	return -EINVAL;
-}
-
-static ssize_t ep93xx_pwm_get_invert(struct device *dev,
-		struct device_attribute *attr, char *buf)
-{
-	struct platform_device *pdev = to_platform_device(dev);
-	struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
-	int inverted = readl(pwm->mmio_base + EP93XX_PWMx_INVERT) & 0x1;
-
-	return sprintf(buf, "%d\n", inverted);
-}
-
-static ssize_t ep93xx_pwm_set_invert(struct device *dev,
-		struct device_attribute *attr, const char *buf, size_t count)
-{
-	struct platform_device *pdev = to_platform_device(dev);
-	struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
-	long val;
-	int err;
-
-	err = kstrtol(buf, 10, &val);
-	if (err)
-		return -EINVAL;
-
-	if (val == 0)
-		writel(0x0, pwm->mmio_base + EP93XX_PWMx_INVERT);
-	else if (val == 1)
-		writel(0x1, pwm->mmio_base + EP93XX_PWMx_INVERT);
-	else
-		return -EINVAL;
-
-	return count;
-}
-
-static DEVICE_ATTR(min_freq, S_IRUGO, ep93xx_pwm_get_min_freq, NULL);
-static DEVICE_ATTR(max_freq, S_IRUGO, ep93xx_pwm_get_max_freq, NULL);
-static DEVICE_ATTR(freq, S_IWUSR | S_IRUGO,
-		   ep93xx_pwm_get_freq, ep93xx_pwm_set_freq);
-static DEVICE_ATTR(duty_percent, S_IWUSR | S_IRUGO,
-		   ep93xx_pwm_get_duty_percent, ep93xx_pwm_set_duty_percent);
-static DEVICE_ATTR(invert, S_IWUSR | S_IRUGO,
-		   ep93xx_pwm_get_invert, ep93xx_pwm_set_invert);
-
-static struct attribute *ep93xx_pwm_attrs[] = {
-	&dev_attr_min_freq.attr,
-	&dev_attr_max_freq.attr,
-	&dev_attr_freq.attr,
-	&dev_attr_duty_percent.attr,
-	&dev_attr_invert.attr,
-	NULL
-};
-
-static const struct attribute_group ep93xx_pwm_sysfs_files = {
-	.attrs	= ep93xx_pwm_attrs,
-};
-
-static int ep93xx_pwm_probe(struct platform_device *pdev)
-{
-	struct ep93xx_pwm *pwm;
-	struct resource *res;
-	int ret;
-
-	pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL);
-	if (!pwm)
-		return -ENOMEM;
-
-	pwm->clk = devm_clk_get(&pdev->dev, "pwm_clk");
-	if (IS_ERR(pwm->clk))
-		return PTR_ERR(pwm->clk);
-
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	pwm->mmio_base = devm_ioremap_resource(&pdev->dev, res);
-	if (IS_ERR(pwm->mmio_base))
-		return PTR_ERR(pwm->mmio_base);
-
-	ret = ep93xx_pwm_acquire_gpio(pdev);
-	if (ret)
-		return ret;
-
-	ret = sysfs_create_group(&pdev->dev.kobj, &ep93xx_pwm_sysfs_files);
-	if (ret) {
-		ep93xx_pwm_release_gpio(pdev);
-		return ret;
-	}
-
-	pwm->duty_percent = 50;
-
-	/* disable pwm at startup. Avoids zero value. */
-	writel(0x0, pwm->mmio_base + EP93XX_PWMx_ENABLE);
-	writel(EP93XX_PWM_MAX_COUNT, pwm->mmio_base + EP93XX_PWMx_TERM_COUNT);
-	writel(EP93XX_PWM_MAX_COUNT/2, pwm->mmio_base + EP93XX_PWMx_DUTY_CYCLE);
-
-	clk_enable(pwm->clk);
-
-	platform_set_drvdata(pdev, pwm);
-	return 0;
-}
-
-static int ep93xx_pwm_remove(struct platform_device *pdev)
-{
-	struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
-
-	writel(0x0, pwm->mmio_base + EP93XX_PWMx_ENABLE);
-	clk_disable(pwm->clk);
-	sysfs_remove_group(&pdev->dev.kobj, &ep93xx_pwm_sysfs_files);
-	ep93xx_pwm_release_gpio(pdev);
-
-	return 0;
-}
-
-static struct platform_driver ep93xx_pwm_driver = {
-	.driver		= {
-		.name	= "ep93xx-pwm",
-		.owner	= THIS_MODULE,
-	},
-	.probe		= ep93xx_pwm_probe,
-	.remove		= ep93xx_pwm_remove,
-};
-module_platform_driver(ep93xx_pwm_driver);
-
-MODULE_AUTHOR("Matthieu Crapet <[e-mail]>, "
-	      "H Hartley Sweeten <[e-mail]>");
-MODULE_DESCRIPTION("EP93xx PWM driver");
-MODULE_LICENSE("GPL");
-MODULE_ALIAS("platform:ep93xx-pwm");

drivers/pwm/Kconfig

···
 	  To compile this driver as a module, choose M here: the module
 	  will be called pwm-bfin.
 
+config PWM_EP93XX
+	tristate "Cirrus Logic EP93xx PWM support"
+	depends on ARCH_EP93XX
+	help
+	  Generic PWM framework driver for Cirrus Logic EP93xx.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called pwm-ep93xx.
+
 config PWM_IMX
 	tristate "i.MX PWM support"
 	depends on ARCH_MXC

drivers/pwm/Makefile

···
 obj-$(CONFIG_PWM_AB8500)	+= pwm-ab8500.o
 obj-$(CONFIG_PWM_ATMEL_TCB)	+= pwm-atmel-tcb.o
 obj-$(CONFIG_PWM_BFIN)		+= pwm-bfin.o
+obj-$(CONFIG_PWM_EP93XX)	+= pwm-ep93xx.o
 obj-$(CONFIG_PWM_IMX)		+= pwm-imx.o
 obj-$(CONFIG_PWM_JZ4740)	+= pwm-jz4740.o
 obj-$(CONFIG_PWM_LPC32XX)	+= pwm-lpc32xx.o

drivers/pwm/pwm-atmel-tcb.c

···
 		}
 	}
 
+	cmr |= (tcbpwm->div & ATMEL_TC_TCCLKS);
+
 	__raw_writel(cmr, regs + ATMEL_TC_REG(group, CMR));
 
 	if (index == 0)
···
 		i = slowclk;
 		rate = 32768;
 		min = div_u64(NSEC_PER_SEC, rate);
-		max = min << 16;
+		max = min << tc->tcb_config->counter_width;
 
 		/* If period is too big return ERANGE error */
 		if (max < period_ns)

drivers/pwm/pwm-ep93xx.c

···
+/*
+ * PWM framework driver for Cirrus Logic EP93xx
+ *
+ * Copyright (c) 2009        Matthieu Crapet <[e-mail]>
+ * Copyright (c) 2009, 2013  H Hartley Sweeten <[e-mail]>
+ *
+ * EP9301/02 have only one channel:
+ *   platform device ep93xx-pwm.1 - PWMOUT1 (EGPIO14)
+ *
+ * EP9307 has only one channel:
+ *   platform device ep93xx-pwm.0 - PWMOUT
+ *
+ * EP9312/15 have two channels:
+ *   platform device ep93xx-pwm.0 - PWMOUT
+ *   platform device ep93xx-pwm.1 - PWMOUT1 (EGPIO14)
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/pwm.h>
+
+#include <asm/div64.h>
+
+#include <mach/platform.h>	/* for ep93xx_pwm_{acquire,release}_gpio() */
+
+#define EP93XX_PWMx_TERM_COUNT	0x00
+#define EP93XX_PWMx_DUTY_CYCLE	0x04
+#define EP93XX_PWMx_ENABLE	0x08
+#define EP93XX_PWMx_INVERT	0x0c
+
+struct ep93xx_pwm {
+	void __iomem *base;
+	struct clk *clk;
+	struct pwm_chip chip;
+};
+
+static inline struct ep93xx_pwm *to_ep93xx_pwm(struct pwm_chip *chip)
+{
+	return container_of(chip, struct ep93xx_pwm, chip);
+}
+
+static int ep93xx_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct platform_device *pdev = to_platform_device(chip->dev);
+
+	return ep93xx_pwm_acquire_gpio(pdev);
+}
+
+static void ep93xx_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct platform_device *pdev = to_platform_device(chip->dev);
+
+	ep93xx_pwm_release_gpio(pdev);
+}
+
+static int ep93xx_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
+			     int duty_ns, int period_ns)
+{
+	struct ep93xx_pwm *ep93xx_pwm = to_ep93xx_pwm(chip);
+	void __iomem *base = ep93xx_pwm->base;
+	unsigned long long c;
+	unsigned long period_cycles;
+	unsigned long duty_cycles;
+	unsigned long term;
+	int ret = 0;
+
+	/*
+	 * The clock needs to be enabled to access the PWM registers.
+	 * Configuration can be changed at any time.
+	 */
+	if (!test_bit(PWMF_ENABLED, &pwm->flags)) {
+		ret = clk_enable(ep93xx_pwm->clk);
+		if (ret)
+			return ret;
+	}
+
+	c = clk_get_rate(ep93xx_pwm->clk);
+	c *= period_ns;
+	do_div(c, 1000000000);
+	period_cycles = c;
+
+	c = period_cycles;
+	c *= duty_ns;
+	do_div(c, period_ns);
+	duty_cycles = c;
+
+	if (period_cycles < 0x10000 && duty_cycles < 0x10000) {
+		term = readw(base + EP93XX_PWMx_TERM_COUNT);
+
+		/* Order is important if PWM is running */
+		if (period_cycles > term) {
+			writew(period_cycles, base + EP93XX_PWMx_TERM_COUNT);
+			writew(duty_cycles, base + EP93XX_PWMx_DUTY_CYCLE);
+		} else {
+			writew(duty_cycles, base + EP93XX_PWMx_DUTY_CYCLE);
+			writew(period_cycles, base + EP93XX_PWMx_TERM_COUNT);
+		}
+	} else {
+		ret = -EINVAL;
+	}
+
+	if (!test_bit(PWMF_ENABLED, &pwm->flags))
+		clk_disable(ep93xx_pwm->clk);
+
+	return ret;
+}
+
+static int ep93xx_pwm_polarity(struct pwm_chip *chip, struct pwm_device *pwm,
+			       enum pwm_polarity polarity)
+{
+	struct ep93xx_pwm *ep93xx_pwm = to_ep93xx_pwm(chip);
+	int ret;
+
+	/*
+	 * The clock needs to be enabled to access the PWM registers.
+	 * Polarity can only be changed when the PWM is disabled.
+	 */
+	ret = clk_enable(ep93xx_pwm->clk);
+	if (ret)
+		return ret;
+
+	if (polarity == PWM_POLARITY_INVERSED)
+		writew(0x1, ep93xx_pwm->base + EP93XX_PWMx_INVERT);
+	else
+		writew(0x0, ep93xx_pwm->base + EP93XX_PWMx_INVERT);
+
+	clk_disable(ep93xx_pwm->clk);
+
+	return 0;
+}
+
+static int ep93xx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct ep93xx_pwm *ep93xx_pwm = to_ep93xx_pwm(chip);
+	int ret;
+
+	ret = clk_enable(ep93xx_pwm->clk);
+	if (ret)
+		return ret;
+
+	writew(0x1, ep93xx_pwm->base + EP93XX_PWMx_ENABLE);
+
+	return 0;
+}
+
+static void ep93xx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct ep93xx_pwm *ep93xx_pwm = to_ep93xx_pwm(chip);
+
+	writew(0x0, ep93xx_pwm->base + EP93XX_PWMx_ENABLE);
+	clk_disable(ep93xx_pwm->clk);
+}
+
+static const struct pwm_ops ep93xx_pwm_ops = {
+	.request = ep93xx_pwm_request,
+	.free = ep93xx_pwm_free,
+	.config = ep93xx_pwm_config,
+	.set_polarity = ep93xx_pwm_polarity,
+	.enable = ep93xx_pwm_enable,
+	.disable = ep93xx_pwm_disable,
+	.owner = THIS_MODULE,
+};
+
+static int ep93xx_pwm_probe(struct platform_device *pdev)
+{
+	struct ep93xx_pwm *ep93xx_pwm;
+	struct resource *res;
+	int ret;
+
+	ep93xx_pwm = devm_kzalloc(&pdev->dev, sizeof(*ep93xx_pwm), GFP_KERNEL);
+	if (!ep93xx_pwm)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	ep93xx_pwm->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(ep93xx_pwm->base))
+		return PTR_ERR(ep93xx_pwm->base);
+
+	ep93xx_pwm->clk = devm_clk_get(&pdev->dev, "pwm_clk");
+	if (IS_ERR(ep93xx_pwm->clk))
+		return PTR_ERR(ep93xx_pwm->clk);
+
+	ep93xx_pwm->chip.dev = &pdev->dev;
+	ep93xx_pwm->chip.ops = &ep93xx_pwm_ops;
+	ep93xx_pwm->chip.base = -1;
+	ep93xx_pwm->chip.npwm = 1;
+
+	ret = pwmchip_add(&ep93xx_pwm->chip);
+	if (ret < 0)
+		return ret;
+
+	platform_set_drvdata(pdev, ep93xx_pwm);
+	return 0;
+}
+
+static int ep93xx_pwm_remove(struct platform_device *pdev)
+{
+	struct ep93xx_pwm *ep93xx_pwm = platform_get_drvdata(pdev);
+
+	return pwmchip_remove(&ep93xx_pwm->chip);
+}
+
+static struct platform_driver ep93xx_pwm_driver = {
+	.driver = {
+		.name = "ep93xx-pwm",
+	},
+	.probe = ep93xx_pwm_probe,
+	.remove = ep93xx_pwm_remove,
+};
+module_platform_driver(ep93xx_pwm_driver);
+
+MODULE_DESCRIPTION("Cirrus Logic EP93xx PWM driver");
+MODULE_AUTHOR("Matthieu Crapet <[e-mail]>, "
+	      "H Hartley Sweeten <[e-mail]>");
+MODULE_ALIAS("platform:ep93xx-pwm");
+MODULE_LICENSE("GPL");

drivers/pwm/pwm-imx.c

···
 #include <linux/clk.h>
 #include <linux/io.h>
 #include <linux/pwm.h>
+#include <linux/of.h>
 #include <linux/of_device.h>
 
 /* i.MX1 and i.MX21 share the same PWM function block: */
···
 	.driver		= {
 		.name	= "imx-pwm",
 		.owner = THIS_MODULE,
-		.of_match_table = of_match_ptr(imx_pwm_dt_ids),
+		.of_match_table = imx_pwm_dt_ids,
 	},
 	.probe		= imx_pwm_probe,
 	.remove		= imx_pwm_remove,

drivers/pwm/pwm-lpc32xx.c

···
 	.driver = {
 		.name = "lpc32xx-pwm",
 		.owner = THIS_MODULE,
-		.of_match_table = of_match_ptr(lpc32xx_pwm_dt_ids),
+		.of_match_table = lpc32xx_pwm_dt_ids,
 	},
 	.probe = lpc32xx_pwm_probe,
 	.remove = lpc32xx_pwm_remove,

drivers/pwm/pwm-mxs.c

···
 	.driver = {
 		.name = "mxs-pwm",
 		.owner = THIS_MODULE,
-		.of_match_table = of_match_ptr(mxs_pwm_dt_ids),
+		.of_match_table = mxs_pwm_dt_ids,
 	},
 	.probe = mxs_pwm_probe,
 	.remove = mxs_pwm_remove,

drivers/pwm/pwm-samsung.c

···
 #include <linux/io.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/pwm.h>
 #include <linux/slab.h>
···
 
 static void pwm_samsung_free(struct pwm_chip *chip, struct pwm_device *pwm)
 {
-	pwm_set_chip_data(pwm, NULL);
 	devm_kfree(chip->dev, pwm_get_chip_data(pwm));
+	pwm_set_chip_data(pwm, NULL);
 }
 
 static int pwm_samsung_enable(struct pwm_chip *chip, struct pwm_device *pwm)

drivers/pwm/pwm-tiecap.c

···
 #include <linux/pm_runtime.h>
 #include <linux/pwm.h>
 #include <linux/of_device.h>
-#include <linux/pinctrl/consumer.h>
 
 #include "pwm-tipwmss.h"
 
···
 	struct clk *clk;
 	struct ecap_pwm_chip *pc;
 	u16 status;
-	struct pinctrl *pinctrl;
-
-	pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
-	if (IS_ERR(pinctrl))
-		dev_warn(&pdev->dev, "unable to select pin group\n");
 
 	pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
 	if (!pc) {

drivers/pwm/pwm-tiehrpwm.c

···
 #include <linux/clk.h>
 #include <linux/pm_runtime.h>
 #include <linux/of_device.h>
-#include <linux/pinctrl/consumer.h>
 
 #include "pwm-tipwmss.h"
 
···
 	struct clk *clk;
 	struct ehrpwm_pwm_chip *pc;
 	u16 status;
-	struct pinctrl *pinctrl;
-
-	pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
-	if (IS_ERR(pinctrl))
-		dev_warn(&pdev->dev, "unable to select pin group\n");
 
 	pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
 	if (!pc) {

drivers/pwm/pwm-twl-led.c

···
  */
 
 #include <linux/module.h>
+#include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/pwm.h>
 #include <linux/i2c/twl.h>

drivers/pwm/pwm-twl.c

···
  */
 
 #include <linux/module.h>
+#include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/pwm.h>
 #include <linux/i2c/twl.h>

drivers/video/backlight/pwm_bl.c

···
  * published by the Free Software Foundation.
  */
 
+#include <linux/gpio.h>
+#include <linux/of_gpio.h>
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
···
 #include <linux/err.h>
 #include <linux/pwm.h>
 #include <linux/pwm_backlight.h>
+#include <linux/regulator/consumer.h>
 #include <linux/slab.h>
 
 struct pwm_bl_data {
···
 	unsigned int		period;
 	unsigned int		lth_brightness;
 	unsigned int		*levels;
+	bool			enabled;
+	struct regulator	*power_supply;
+	int			enable_gpio;
+	unsigned long		enable_gpio_flags;
+	unsigned int		scale;
 	int			(*notify)(struct device *,
 					  int brightness);
 	void			(*notify_after)(struct device *,
···
 	void			(*exit)(struct device *);
 };
 
+static void pwm_backlight_power_on(struct pwm_bl_data *pb, int brightness)
+{
+	int err;
+
+	if (pb->enabled)
+		return;
+
+	err = regulator_enable(pb->power_supply);
+	if (err < 0)
+		dev_err(pb->dev, "failed to enable power supply\n");
+
+	if (gpio_is_valid(pb->enable_gpio)) {
+		if (pb->enable_gpio_flags & PWM_BACKLIGHT_GPIO_ACTIVE_LOW)
+			gpio_set_value(pb->enable_gpio, 0);
+		else
+			gpio_set_value(pb->enable_gpio, 1);
+	}
+
+	pwm_enable(pb->pwm);
+	pb->enabled = true;
+}
+
+static void pwm_backlight_power_off(struct pwm_bl_data *pb)
+{
+	if (!pb->enabled)
+		return;
+
+	pwm_config(pb->pwm, 0, pb->period);
+	pwm_disable(pb->pwm);
+
+	if (gpio_is_valid(pb->enable_gpio)) {
+		if (pb->enable_gpio_flags & PWM_BACKLIGHT_GPIO_ACTIVE_LOW)
+			gpio_set_value(pb->enable_gpio, 1);
+		else
+			gpio_set_value(pb->enable_gpio, 0);
+	}
+
+	regulator_disable(pb->power_supply);
+	pb->enabled = false;
+}
+
+static int compute_duty_cycle(struct pwm_bl_data *pb, int brightness)
+{
+	unsigned int lth = pb->lth_brightness;
+	int duty_cycle;
+
+	if (pb->levels)
+		duty_cycle = pb->levels[brightness];
+	else
+		duty_cycle = brightness;
+
+	return (duty_cycle * (pb->period - lth) / pb->scale) + lth;
+}
+
 static int pwm_backlight_update_status(struct backlight_device *bl)
 {
 	struct pwm_bl_data *pb = bl_get_data(bl);
 	int brightness = bl->props.brightness;
-	int max = bl->props.max_brightness;
+	int duty_cycle;
 
 	if (bl->props.power != FB_BLANK_UNBLANK ||
 	    bl->props.fb_blank != FB_BLANK_UNBLANK ||
···
 	if (pb->notify)
 		brightness = pb->notify(pb->dev, brightness);
 
-	if (brightness == 0) {
-		pwm_config(pb->pwm, 0, pb->period);
-		pwm_disable(pb->pwm);
-	} else {
-		int duty_cycle;
-
-		if (pb->levels) {
-			duty_cycle = pb->levels[brightness];
-			max = pb->levels[max];
-		} else {
-			duty_cycle = brightness;
-		}
-
-		duty_cycle = pb->lth_brightness +
-		     (duty_cycle * (pb->period - pb->lth_brightness) / max);
+	if (brightness > 0) {
+		duty_cycle = compute_duty_cycle(pb, brightness);
 		pwm_config(pb->pwm, duty_cycle, pb->period);
-		pwm_enable(pb->pwm);
-	}
+		pwm_backlight_power_on(pb, brightness);
+	} else
+		pwm_backlight_power_off(pb);
 
 	if (pb->notify_after)
 		pb->notify_after(pb->dev, brightness);
···
 				  struct platform_pwm_backlight_data *data)
 {
 	struct device_node *node = dev->of_node;
+	enum of_gpio_flags flags;
 	struct property *prop;
 	int length;
 	u32 value;
···
 		data->max_brightness--;
 	}
 
-	/*
-	 * TODO: Most users of this driver use a number of GPIOs to control
-	 *       backlight power. Support for specifying these needs to be
-	 *       added.
-	 */
+	data->enable_gpio = of_get_named_gpio_flags(node, "enable-gpios", 0,
+						    &flags);
+	if (data->enable_gpio == -EPROBE_DEFER)
+		return -EPROBE_DEFER;
+
+	if (gpio_is_valid(data->enable_gpio) && (flags & OF_GPIO_ACTIVE_LOW))
+		data->enable_gpio_flags |= PWM_BACKLIGHT_GPIO_ACTIVE_LOW;
 
 	return 0;
 }
···
 	struct backlight_properties props;
 	struct backlight_device *bl;
 	struct pwm_bl_data *pb;
-	unsigned int max;
 	int ret;
 
 	if (!data) {
···
 	}
 
 	if (data->levels) {
-		max = data->levels[data->max_brightness];
+		unsigned int i;
+
+		for (i = 0; i <= data->max_brightness; i++)
+			if (data->levels[i] > pb->scale)
+				pb->scale = data->levels[i];
+
 		pb->levels = data->levels;
 	} else
-		max = data->max_brightness;
+		pb->scale = data->max_brightness;
 
+	pb->enable_gpio = data->enable_gpio;
+	pb->enable_gpio_flags = data->enable_gpio_flags;
 	pb->notify = data->notify;
 	pb->notify_after = data->notify_after;
 	pb->check_fb = data->check_fb;
 	pb->exit = data->exit;
 	pb->dev = &pdev->dev;
+	pb->enabled = false;
+
+	if (gpio_is_valid(pb->enable_gpio)) {
+		unsigned long flags;
+
+		if (pb->enable_gpio_flags & PWM_BACKLIGHT_GPIO_ACTIVE_LOW)
+			flags = GPIOF_OUT_INIT_HIGH;
+		else
+			flags = GPIOF_OUT_INIT_LOW;
+
+		ret = gpio_request_one(pb->enable_gpio, flags, "enable");
+		if (ret < 0) {
+			dev_err(&pdev->dev, "failed to request GPIO#%d: %d\n",
+				pb->enable_gpio, ret);
+			goto err_alloc;
+		}
+	}
+
+	pb->power_supply = devm_regulator_get(&pdev->dev, "power");
+	if (IS_ERR(pb->power_supply)) {
+		ret = PTR_ERR(pb->power_supply);
+		goto err_gpio;
+	}
 
 	pb->pwm = devm_pwm_get(&pdev->dev, NULL);
 	if (IS_ERR(pb->pwm)) {
···
 		if (IS_ERR(pb->pwm)) {
 			dev_err(&pdev->dev, "unable to request legacy PWM\n");
 			ret = PTR_ERR(pb->pwm);
-			goto err_alloc;
+			goto err_gpio;
 		}
 	}
 
···
 		pwm_set_period(pb->pwm, data->pwm_period_ns);
 
 	pb->period = pwm_get_period(pb->pwm);
-	pb->lth_brightness = data->lth_brightness * (pb->period / max);
+	pb->lth_brightness = data->lth_brightness * (pb->period / pb->scale);
 
 	memset(&props, 0, sizeof(struct backlight_properties));
 	props.type = BACKLIGHT_RAW;
···
 	if (IS_ERR(bl)) {
 		dev_err(&pdev->dev, "failed to register backlight\n");
 		ret = PTR_ERR(bl);
-		goto err_alloc;
+		goto err_gpio;
 	}
 
 	if (data->dft_brightness > data->max_brightness) {
···
 	platform_set_drvdata(pdev, bl);
 	return 0;
 
+err_gpio:
+	if (gpio_is_valid(pb->enable_gpio))
+		gpio_free(pb->enable_gpio);
 err_alloc:
 	if (data->exit)
 		data->exit(&pdev->dev);
···
 	struct pwm_bl_data *pb = bl_get_data(bl);
 
 	backlight_device_unregister(bl);
-	pwm_config(pb->pwm, 0, pb->period);
-	pwm_disable(pb->pwm);
+	pwm_backlight_power_off(pb);
+
 	if (pb->exit)
 		pb->exit(&pdev->dev);
+
 	return 0;
 }
 
···
 
 	if (pb->notify)
 		pb->notify(pb->dev, 0);
-	pwm_config(pb->pwm, 0, pb->period);
-	pwm_disable(pb->pwm);
+
+	pwm_backlight_power_off(pb);
+
 	if (pb->notify_after)
 		pb->notify_after(pb->dev, 0);
+
 	return 0;
 }
 
···
 	struct backlight_device *bl = dev_get_drvdata(dev);
 
 	backlight_update_status(bl);
+
 	return 0;
 }
 #endif
 
-static SIMPLE_DEV_PM_OPS(pwm_backlight_pm_ops, pwm_backlight_suspend,
-			 pwm_backlight_resume);
+static const struct dev_pm_ops pwm_backlight_pm_ops = {
+#ifdef CONFIG_PM_SLEEP
+	.suspend = pwm_backlight_suspend,
+	.resume = pwm_backlight_resume,
+	.poweroff = pwm_backlight_suspend,
+	.restore = pwm_backlight_resume,
+#endif
+};
 
 static struct platform_driver pwm_backlight_driver = {
 	.driver		= {
···
 MODULE_DESCRIPTION("PWM based Backlight Driver");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("platform:pwm-backlight");
-

include/linux/pwm_backlight.h

···
 
 #include <linux/backlight.h>
 
+/* TODO: convert to gpiod_*() API once it has been merged */
+#define PWM_BACKLIGHT_GPIO_ACTIVE_LOW	(1 << 0)
+
 struct platform_pwm_backlight_data {
 	int pwm_id;
 	unsigned int max_brightness;
···
 	unsigned int lth_brightness;
 	unsigned int pwm_period_ns;
 	unsigned int *levels;
+	int enable_gpio;
+	unsigned long enable_gpio_flags;
 	int (*init)(struct device *dev);
 	int (*notify)(struct device *dev, int brightness);
 	void (*notify_after)(struct device *dev, int brightness);