[PATCH 1/6] video: stmfb: Add device tree support

[PATCH 1/6] video: stmfb: Add device tree support

[Sascha Hauer]

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 drivers/video/stm.c | 52 ++++++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 42 insertions(+), 10 deletions(-)

diff --git a/drivers/video/stm.c b/drivers/video/stm.c
index 3c90c0d..bf913f1 100644
--- a/drivers/video/stm.c
+++ b/drivers/video/stm.c
@@ -317,7 +317,7 @@ static int stmfb_activate_var(struct fb_info *fb_info)
 	size = calc_line_length(mode->xres, fb_info->bits_per_pixel) *
 		mode->yres;
 
-	if (pdata->fixed_screen) {
+	if (pdata && pdata->fixed_screen) {
 		if (pdata->fixed_screen_size < size)
 			return -ENOMEM;
 		fb_info->screen_base = pdata->fixed_screen;
@@ -497,16 +497,37 @@ static int stmfb_probe(struct device_d *hw_dev)
 		return PTR_ERR(fbi.clk);
 	clk_enable(fbi.clk);
 
+	fbi.info.bits_per_pixel = 16;
+
 	/* add runtime video info */
-	fbi.info.modes.modes = pdata->mode_list;
-	fbi.info.modes.num_modes = pdata->mode_cnt;
-	fbi.info.mode = &fbi.info.modes.modes[0];
-	fbi.info.xres = fbi.info.mode->xres;
-	fbi.info.yres = fbi.info.mode->yres;
-	if (pdata->bits_per_pixel)
-		fbi.info.bits_per_pixel = pdata->bits_per_pixel;
-	else
-		fbi.info.bits_per_pixel = 16;
+	if (pdata) {
+		fbi.info.modes.modes = pdata->mode_list;
+		fbi.info.modes.num_modes = pdata->mode_cnt;
+		fbi.info.mode = &fbi.info.modes.modes[0];
+		if (pdata->bits_per_pixel)
+			fbi.info.bits_per_pixel = pdata->bits_per_pixel;
+	} else {
+		struct display_timings *modes;
+		struct device_node *display;
+
+		if (!IS_ENABLED(CONFIG_OFDEVICE) || !hw_dev->device_node)
+			return -EINVAL;
+
+		display = of_parse_phandle(hw_dev->device_node, "display", 0);
+		if (!display) {
+			dev_err(hw_dev, "no display phandle\n");
+			return -EINVAL;
+		}
+
+		modes = of_get_display_timings(display);
+		if (IS_ERR(modes)) {
+			dev_err(hw_dev, "unable to parse display timings\n");
+			return PTR_ERR(modes);
+		}
+
+		fbi.info.modes.modes = modes->modes;
+		fbi.info.modes.num_modes = modes->num_modes;
+	}
 
 	hw_dev->info = stmfb_info;
 
@@ -519,9 +540,20 @@ static int stmfb_probe(struct device_d *hw_dev)
 	return 0;
 }
 
+static __maybe_unused struct of_device_id stmfb_compatible[] = {
+	{
+		.compatible = "fsl,imx23-lcdif",
+	}, {
+		.compatible = "fsl,imx28-lcdif",
+	}, {
+		/* sentinel */
+	}
+};
+
 static struct driver_d stmfb_driver = {
 	.name	= "stmfb",
 	.probe	= stmfb_probe,
+	.of_compatible = DRV_OF_COMPAT(stmfb_compatible),
 };
 device_platform_driver(stmfb_driver);
 
-- 
2.1.4


_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox

[PATCH 2/6] video: Add backlight support

[Sascha Hauer]

This adds a small backlight layer. It provides a backlight device
on which the brightness parameter can be used to adjust the brightness.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 drivers/video/Kconfig     |  4 +++
 drivers/video/Makefile    |  1 +
 drivers/video/backlight.c | 90 +++++++++++++++++++++++++++++++++++++++++++++++
 include/video/backlight.h | 20 +++++++++++
 4 files changed, 115 insertions(+)
 create mode 100644 drivers/video/backlight.c
 create mode 100644 include/video/backlight.h

diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index f096a54..e108d8a 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -93,4 +93,8 @@ config DRIVER_VIDEO_EDID
 	  This enabled support for reading and parsing EDID data from an attached
 	  monitor.
 
+config DRIVER_VIDEO_BACKLIGHT
+	bool "Add backlight support"
+	help
+	  Enable this for backlight support.
 endif
diff --git a/drivers/video/Makefile b/drivers/video/Makefile
index ae9f6e5..0655b0f 100644
--- a/drivers/video/Makefile
+++ b/drivers/video/Makefile
@@ -1,6 +1,7 @@
 obj-$(CONFIG_VIDEO) += fb.o
 obj-$(CONFIG_DRIVER_VIDEO_EDID) += edid.o
 obj-$(CONFIG_OFDEVICE) += of_display_timing.o
+obj-$(CONFIG_DRIVER_VIDEO_BACKLIGHT) += backlight.o
 
 obj-$(CONFIG_DRIVER_VIDEO_ATMEL) += atmel_lcdfb.o atmel_lcdfb_core.o
 obj-$(CONFIG_DRIVER_VIDEO_ATMEL_HLCD) += atmel_hlcdfb.o atmel_lcdfb_core.o
diff --git a/drivers/video/backlight.c b/drivers/video/backlight.c
new file mode 100644
index 0000000..ddde6f8
--- /dev/null
+++ b/drivers/video/backlight.c
@@ -0,0 +1,90 @@
+#include <common.h>
+#include <driver.h>
+#include <linux/list.h>
+#include <video/backlight.h>
+
+static LIST_HEAD(backlights);
+
+int backlight_set_brightness(struct backlight_device *bl, int brightness)
+{
+	int ret, step, i, num_steps;
+
+	if (brightness > bl->brightness_max)
+		brightness = bl->brightness_max;
+
+	if (brightness == bl->brightness_cur)
+		return 0;
+
+	if (brightness > bl->brightness_cur)
+		step = 1;
+	else
+		step = -1;
+
+	i = bl->brightness_cur;
+
+	num_steps = abs(brightness - bl->brightness_cur);
+
+	while (1) {
+		i += step;
+
+		ret = bl->brightness_set(bl, i);
+		if (ret)
+			return ret;
+
+		if (i == brightness)
+			break;
+
+		udelay(100000 / num_steps);
+	}
+
+
+	bl->brightness_cur = bl->brightness = brightness;
+
+	return ret;
+}
+
+int backlight_set_brightness_default(struct backlight_device *bl)
+{
+	int ret;
+
+	ret = backlight_set_brightness(bl, bl->brightness_default);
+
+	return ret;
+}
+
+static int backlight_brightness_set(struct param_d *p, void *priv)
+{
+	struct backlight_device *bl = priv;
+
+	return backlight_set_brightness(bl, bl->brightness);
+}
+
+int backlight_register(struct backlight_device *bl)
+{
+	int ret;
+
+	sprintf(bl->dev.name, "backlight");
+	bl->dev.id = DEVICE_ID_DYNAMIC;
+
+	ret = register_device(&bl->dev);
+	if (ret)
+		return ret;
+
+	dev_add_param_int(&bl->dev, "brightness", backlight_brightness_set,
+			NULL, &bl->brightness, "%d", bl);
+
+	list_add_tail(&bl->list, &backlights);
+
+	return ret;
+}
+
+struct backlight_device *of_backlight_find(struct device_node *node)
+{
+	struct backlight_device *bl;
+
+	list_for_each_entry(bl, &backlights, list)
+		if (bl->node == node)
+			return bl;
+
+	return NULL;
+}
diff --git a/include/video/backlight.h b/include/video/backlight.h
new file mode 100644
index 0000000..56e0341
--- /dev/null
+++ b/include/video/backlight.h
@@ -0,0 +1,20 @@
+#ifndef __VIDEO_BACKLIGHT_H
+#define __VIDEO_BACKLIGHT_H
+
+struct backlight_device {
+	int brightness;
+	int brightness_cur;
+	int brightness_max;
+	int brightness_default;
+	int (*brightness_set)(struct backlight_device *, int brightness);
+	struct list_head list;
+	struct device_d dev;
+	struct device_node *node;
+};
+
+int backlight_set_brightness(struct backlight_device *, int brightness);
+int backlight_set_brightness_default(struct backlight_device *);
+int backlight_register(struct backlight_device *);
+struct backlight_device *of_backlight_find(struct device_node *node);
+
+#endif /* __VIDEO_BACKLIGHT_H */
-- 
2.1.4


_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox

[PATCH 3/6] video: Add PWM backlight support

[Sascha Hauer]

This adds a backlight driver for backlights controlled by a PWM.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 drivers/video/Kconfig         |   8 ++
 drivers/video/Makefile        |   1 +
 drivers/video/backlight-pwm.c | 199 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 208 insertions(+)
 create mode 100644 drivers/video/backlight-pwm.c

diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index e108d8a..8e6ae99 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -97,4 +97,12 @@ config DRIVER_VIDEO_BACKLIGHT
 	bool "Add backlight support"
 	help
 	  Enable this for backlight support.
+
+config DRIVER_VIDEO_BACKLIGHT_PWM
+	bool "PWM backlight support"
+	depends on PWM
+	depends on DRIVER_VIDEO_BACKLIGHT
+	help
+	  Enable this to get support for backlight devices driven by a PWM.
+
 endif
diff --git a/drivers/video/Makefile b/drivers/video/Makefile
index 0655b0f..76fad5c 100644
--- a/drivers/video/Makefile
+++ b/drivers/video/Makefile
@@ -2,6 +2,7 @@ obj-$(CONFIG_VIDEO) += fb.o
 obj-$(CONFIG_DRIVER_VIDEO_EDID) += edid.o
 obj-$(CONFIG_OFDEVICE) += of_display_timing.o
 obj-$(CONFIG_DRIVER_VIDEO_BACKLIGHT) += backlight.o
+obj-$(CONFIG_DRIVER_VIDEO_BACKLIGHT_PWM) += backlight-pwm.o
 
 obj-$(CONFIG_DRIVER_VIDEO_ATMEL) += atmel_lcdfb.o atmel_lcdfb_core.o
 obj-$(CONFIG_DRIVER_VIDEO_ATMEL_HLCD) += atmel_hlcdfb.o atmel_lcdfb_core.o
diff --git a/drivers/video/backlight-pwm.c b/drivers/video/backlight-pwm.c
new file mode 100644
index 0000000..ae0b0ca
--- /dev/null
+++ b/drivers/video/backlight-pwm.c
@@ -0,0 +1,199 @@
+/*
+ * pwm backlight support for barebox
+ *
+ * (C) Copyright 2014 Sascha Hauer, Pengutronix
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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 <common.h>
+#include <malloc.h>
+#include <init.h>
+#include <video/backlight.h>
+#include <pwm.h>
+#include <linux/err.h>
+#include <of.h>
+#include <gpio.h>
+#include <of_gpio.h>
+#include <asm-generic/div64.h>
+
+struct pwm_backlight {
+	struct backlight_device backlight;
+	struct pwm_device *pwm;
+	uint32_t period;
+	unsigned int *levels;
+	int enable_gpio;
+	int enable_active_high;
+	int max_value;
+	int enabled;
+};
+
+static int backlight_pwm_enable(struct pwm_backlight *pwm_backlight)
+{
+	int ret;
+
+	if (pwm_backlight->enabled)
+		return 0;
+
+	ret = pwm_enable(pwm_backlight->pwm);
+	if (ret)
+		return ret;
+
+	if (gpio_is_valid(pwm_backlight->enable_gpio)) {
+		gpio_direction_output(pwm_backlight->enable_gpio,
+				pwm_backlight->enable_active_high);
+	}
+
+	pwm_backlight->enabled = 1;
+
+	return 0;
+}
+
+static int backlight_pwm_disable(struct pwm_backlight *pwm_backlight)
+{
+	if (!pwm_backlight->enabled)
+		return 0;
+
+	if (gpio_is_valid(pwm_backlight->enable_gpio)) {
+		gpio_direction_output(pwm_backlight->enable_gpio,
+				!pwm_backlight->enable_active_high);
+		/*
+		 * Only disable PWM when an enable gpio is present.
+		 * The output of the PWM is undefined when the PWM
+		 * is disabled.
+		 */
+		pwm_disable(pwm_backlight->pwm);
+		pwm_backlight->enabled = 0;
+	}
+
+	return 0;
+}
+
+static int backlight_pwm_set(struct backlight_device *backlight,
+		int brightness)
+{
+	struct pwm_backlight *pwm_backlight = container_of(backlight,
+			struct pwm_backlight, backlight);
+	unsigned long long duty =  pwm_backlight->period;
+	unsigned int max = pwm_backlight->backlight.brightness_max;
+
+        duty *= brightness;
+        do_div(duty, max);
+
+	pwm_config(pwm_backlight->pwm, duty, pwm_backlight->period);
+
+	if (brightness)
+		return backlight_pwm_enable(pwm_backlight);
+	else
+		return backlight_pwm_disable(pwm_backlight);
+}
+
+static int pwm_backlight_parse_dt(struct device_d *dev,
+		struct pwm_backlight *pwm_backlight)
+{
+	struct device_node *node = dev->device_node;
+	struct property *prop;
+	int length;
+	u32 value;
+	int ret;
+	enum of_gpio_flags flags;
+
+	if (!node)
+		return -ENODEV;
+
+	/* determine the number of brightness levels */
+	prop = of_find_property(node, "brightness-levels", &length);
+	if (!prop)
+		return -EINVAL;
+
+	pwm_backlight->backlight.brightness_max = length / sizeof(u32);
+
+	/* read brightness levels from DT property */
+	if (pwm_backlight->backlight.brightness_max > 0) {
+		size_t size = sizeof(*pwm_backlight->levels) *
+			pwm_backlight->backlight.brightness_max;
+
+		pwm_backlight->levels = xzalloc(size);
+		if (!pwm_backlight->levels)
+			return -ENOMEM;
+
+		ret = of_property_read_u32_array(node, "brightness-levels",
+						 pwm_backlight->levels,
+						 pwm_backlight->backlight.brightness_max);
+		if (ret < 0)
+			return ret;
+
+		ret = of_property_read_u32(node, "default-brightness-level",
+					   &value);
+		if (ret < 0)
+			return ret;
+
+		pwm_backlight->backlight.brightness_default = value;
+		pwm_backlight->backlight.brightness_max--;
+	}
+
+	pwm_backlight->enable_gpio = of_get_named_gpio_flags(node, "enable-gpios", 0, &flags);
+
+	if (gpio_is_valid(pwm_backlight->enable_gpio)) {
+		if (!(flags & OF_GPIO_ACTIVE_LOW))
+			pwm_backlight->enable_active_high = 1;
+	}
+
+	return 0;
+}
+
+static int backlight_pwm_of_probe(struct device_d *dev)
+{
+	int ret;
+	struct pwm_backlight *pwm_backlight;
+	struct pwm_device *pwm;
+
+	pwm = of_pwm_request(dev->device_node, NULL);
+	if (IS_ERR(pwm))
+		return PTR_ERR(pwm);
+
+	pwm_backlight = xzalloc(sizeof(*pwm_backlight));
+	pwm_backlight->pwm = pwm;
+	pwm_backlight->period = pwm_get_period(pwm);
+
+	ret = pwm_backlight_parse_dt(dev, pwm_backlight);
+	if (ret)
+		return ret;
+
+	pwm_backlight->period = pwm_get_period(pwm_backlight->pwm);
+
+	pwm_backlight->backlight.brightness_set = backlight_pwm_set;
+	pwm_backlight->backlight.node = dev->device_node;
+
+	ret = backlight_register(&pwm_backlight->backlight);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static struct of_device_id backlight_pwm_of_ids[] = {
+	{
+		.compatible = "pwm-backlight",
+	}, {
+		/* sentinel */
+	}
+};
+
+static struct driver_d backlight_pwm_of_driver = {
+	.name  = "pwm-backlight",
+	.probe = backlight_pwm_of_probe,
+	.of_compatible = DRV_OF_COMPAT(backlight_pwm_of_ids),
+};
+device_platform_driver(backlight_pwm_of_driver);
-- 
2.1.4


_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox

[PATCH 4/6] ARM: i.MX28: Add PWM clk support

[Sascha Hauer]

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 arch/arm/mach-mxs/include/mach/imx28-regs.h | 1 +
 drivers/clk/mxs/clk-imx28.c                 | 1 +
 2 files changed, 2 insertions(+)

diff --git a/arch/arm/mach-mxs/include/mach/imx28-regs.h b/arch/arm/mach-mxs/include/mach/imx28-regs.h
index de0d882..1a90ec2 100644
--- a/arch/arm/mach-mxs/include/mach/imx28-regs.h
+++ b/arch/arm/mach-mxs/include/mach/imx28-regs.h
@@ -34,6 +34,7 @@
 #define IMX_WDT_BASE		0x80056000
 #define IMX_I2C0_BASE		0x80058000
 #define IMX_I2C1_BASE		0x8005a000
+#define IMX_PWM_BASE		0x80064000
 #define IMX_TIM1_BASE		0x80068000
 #define IMX_UART0_BASE		0x8006a000
 #define IMX_UART1_BASE		0x8006c000
diff --git a/drivers/clk/mxs/clk-imx28.c b/drivers/clk/mxs/clk-imx28.c
index 77a13bc..a408044 100644
--- a/drivers/clk/mxs/clk-imx28.c
+++ b/drivers/clk/mxs/clk-imx28.c
@@ -158,6 +158,7 @@ int __init mx28_clocks_init(void __iomem *regs)
 	clkdev_add_physbase(clks[uart], IMX_UART3_BASE, NULL);
 	clkdev_add_physbase(clks[uart], IMX_UART4_BASE, NULL);
 	clkdev_add_physbase(clks[gpmi], MXS_GPMI_BASE, NULL);
+	clkdev_add_physbase(clks[pwm], IMX_PWM_BASE, NULL);
 	if (IS_ENABLED(CONFIG_DRIVER_VIDEO_STM))
 		clkdev_add_physbase(clks[lcdif_comp], IMX_FB_BASE, NULL);
 
-- 
2.1.4


_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox

[PATCH 5/6] PWM: Allow multiple PWMs per device node

[Sascha Hauer]

Matching a device node is enough since a device node may have
multiple PWMs. Check for a id aswell.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 drivers/pwm/core.c | 7 ++++---
 include/pwm.h      | 2 ++
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index cc33dec..3605201 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -181,12 +181,13 @@ struct pwm_device *pwm_request(const char *devname)
 }
 EXPORT_SYMBOL_GPL(pwm_request);
 
-static struct pwm_device *of_node_to_pwm_device(struct device_node *np)
+static struct pwm_device *of_node_to_pwm_device(struct device_node *np, int id)
 {
 	struct pwm_device *pwm;
 
 	list_for_each_entry(pwm, &pwm_list, node) {
-		if (pwm->hwdev && pwm->hwdev->device_node == np)
+		if (pwm->hwdev && pwm->hwdev->device_node == np &&
+				pwm->chip->id == id)
 			return pwm;
 	}
 
@@ -210,7 +211,7 @@ struct pwm_device *of_pwm_request(struct device_node *np, const char *con_id)
 		return ERR_PTR(ret);
 	}
 
-	pwm = of_node_to_pwm_device(args.np);
+	pwm = of_node_to_pwm_device(args.np, args.args[0]);
 	if (IS_ERR(pwm)) {
 		pr_debug("%s(): PWM chip not found\n", __func__);
 		return pwm;
diff --git a/include/pwm.h b/include/pwm.h
index 59d86d4..911c760 100644
--- a/include/pwm.h
+++ b/include/pwm.h
@@ -57,12 +57,14 @@ struct pwm_ops {
 
 /**
  * struct pwm_chip - abstract a PWM
+ * @id: The id of this pwm
  * @devname: unique identifier for this pwm
  * @ops: The callbacks for this PWM
  * @duty_ns: The duty cycle of the PWM, in nano-seconds
  * @period_ns: The period of the PWM, in nano-seconds
  */
 struct pwm_chip {
+	int			id;
 	const char		*devname;
 	struct pwm_ops		*ops;
 	int			duty_ns;
-- 
2.1.4


_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox

[PATCH 6/6] PWM: Add MXS PWM support

[Sascha Hauer]

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 drivers/pwm/Kconfig   |   6 ++
 drivers/pwm/Makefile  |   1 +
 drivers/pwm/pwm-mxs.c | 174 ++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 181 insertions(+)
 create mode 100644 drivers/pwm/pwm-mxs.c

diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 8324d5e..97c3def 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -22,4 +22,10 @@ config PWM_IMX
 	help
 	  This enables PWM support for Freescale i.MX SoCs
 
+config PWM_MXS
+	bool "i.MXs PWM Support"
+	depends on ARCH_MXS
+	help
+	  This enables PWM support for Freescale i.MX23/i.MX28 SoCs
+
 endif
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index dea9956..46865a2 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -1,3 +1,4 @@
 obj-$(CONFIG_PWM)		+= core.o
 obj-$(CONFIG_PWM_PXA)		+= pxa_pwm.o
 obj-$(CONFIG_PWM_IMX)		+= pwm-imx.o
+obj-$(CONFIG_PWM_MXS)		+= pwm-mxs.o
diff --git a/drivers/pwm/pwm-mxs.c b/drivers/pwm/pwm-mxs.c
new file mode 100644
index 0000000..e667442
--- /dev/null
+++ b/drivers/pwm/pwm-mxs.c
@@ -0,0 +1,174 @@
+/*
+ * Copyright 2012 Freescale Semiconductor, Inc.
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include <common.h>
+#include <init.h>
+#include <errno.h>
+#include <io.h>
+#include <pwm.h>
+#include <stmp-device.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <asm-generic/div64.h>
+
+#define SET	0x4
+#define CLR	0x8
+#define TOG	0xc
+
+#define PWM_CTRL		0x0
+#define PWM_ACTIVE0		0x10
+#define PWM_PERIOD0		0x20
+#define  PERIOD_PERIOD(p)	((p) & 0xffff)
+#define  PERIOD_PERIOD_MAX	0x10000
+#define  PERIOD_ACTIVE_HIGH	(3 << 16)
+#define  PERIOD_INACTIVE_LOW	(2 << 18)
+#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;
+
+struct mxs_pwm_chip {
+	struct pwm_chip chip;
+	struct mxs_pwm *mxs;
+};
+
+struct mxs_pwm {
+	struct mxs_pwm_chip pwm[8];
+	struct clk *clk;
+	void __iomem *base;
+};
+
+#define to_mxs_pwm_chip(_chip) container_of(_chip, struct mxs_pwm_chip, chip)
+
+static int mxs_pwm_config(struct pwm_chip *chip, int duty_ns, int period_ns)
+{
+	struct mxs_pwm_chip *mxs = to_mxs_pwm_chip(chip);
+	int div = 0;
+	unsigned int period_cycles, duty_cycles;
+	unsigned long rate;
+	unsigned long long c;
+
+	rate = clk_get_rate(mxs->mxs->clk);
+	while (1) {
+		c = rate / cdiv[div];
+		c = c * period_ns;
+		do_div(c, 1000000000);
+		if (c < PERIOD_PERIOD_MAX)
+			break;
+		div++;
+		if (div >= PERIOD_CDIV_MAX)
+			return -EINVAL;
+	}
+
+	period_cycles = c;
+	c *= duty_ns;
+	do_div(c, period_ns);
+	duty_cycles = c;
+
+	writel(duty_cycles << 16,
+			mxs->mxs->base + PWM_ACTIVE0 + mxs->chip.id * 0x20);
+	writel(PERIOD_PERIOD(period_cycles) | PERIOD_ACTIVE_HIGH |
+	       PERIOD_INACTIVE_LOW | PERIOD_CDIV(div),
+			mxs->mxs->base + PWM_PERIOD0 + mxs->chip.id * 0x20);
+
+	return 0;
+}
+
+static int mxs_pwm_enable(struct pwm_chip *chip)
+{
+	struct mxs_pwm_chip *mxs = to_mxs_pwm_chip(chip);
+
+	writel(1 << mxs->chip.id, mxs->mxs->base + PWM_CTRL + SET);
+
+	return 0;
+}
+
+static void mxs_pwm_disable(struct pwm_chip *chip)
+{
+	struct mxs_pwm_chip *mxs = to_mxs_pwm_chip(chip);
+
+	writel(1 << mxs->chip.id, mxs->mxs->base + PWM_CTRL + CLR);
+}
+
+static struct pwm_ops mxs_pwm_ops = {
+	.config = mxs_pwm_config,
+	.enable = mxs_pwm_enable,
+	.disable = mxs_pwm_disable,
+};
+
+static int mxs_pwm_probe(struct device_d *dev)
+{
+	struct device_node *np = dev->device_node;
+	struct mxs_pwm *mxs;
+	int ret, i;
+	uint32_t npwm;
+
+	mxs = xzalloc(sizeof(*mxs));
+
+	mxs->base = dev_request_mem_region(dev, 0);
+	if (IS_ERR(mxs->base))
+		return PTR_ERR(mxs->base);
+
+	mxs->clk = clk_get(dev, NULL);
+	if (IS_ERR(mxs->clk))
+		return PTR_ERR(mxs->clk);
+
+	clk_enable(mxs->clk);
+
+	ret = stmp_reset_block(mxs->base, 0);
+	if (ret)
+		return ret;
+
+	ret = of_property_read_u32(np, "fsl,pwm-number", &npwm);
+	if (ret < 0) {
+		dev_err(dev, "failed to get pwm number: %d\n", ret);
+		return ret;
+	}
+
+	for (i = 0; i < npwm; i++) {
+		struct mxs_pwm_chip *mxspwm = &mxs->pwm[i];
+
+		mxspwm->chip.ops = &mxs_pwm_ops;
+		mxspwm->chip.devname = asprintf("pwm%d", i);
+		mxspwm->chip.id = i;
+		mxspwm->mxs = mxs;
+
+		ret = pwmchip_add(&mxspwm->chip, dev);
+		if (ret < 0) {
+			dev_err(dev, "failed to add pwm chip %d\n", ret);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static const struct of_device_id mxs_pwm_dt_ids[] = {
+	{ .compatible = "fsl,imx23-pwm", },
+	{ /* sentinel */ }
+};
+
+static struct driver_d mxs_pwm_driver = {
+	.name	= "mxs-pwm",
+	.of_compatible	= mxs_pwm_dt_ids,
+	.probe		= mxs_pwm_probe,
+};
+
+coredevice_platform_driver(mxs_pwm_driver);
+
+MODULE_ALIAS("platform:mxs-pwm");
+MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>");
+MODULE_DESCRIPTION("Freescale MXS PWM Driver");
+MODULE_LICENSE("GPL v2");
-- 
2.1.4


_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox

Re: [PATCH 3/6] video: Add PWM backlight support

[Marc Kleine-Budde]

[-- Attachment #1.1: Type: text/plain, Size: 821 bytes --]

On 06/12/2015 11:53 AM, Sascha Hauer wrote:
> +static·int·backlight_pwm_set(struct·backlight_device·*backlight,
> +» » int·brightness)
> +{
> +» struct·pwm_backlight·*pwm_backlight·=·container_of(backlight,
> +» » » struct·pwm_backlight,·backlight);
> +» unsigned·long·long·duty·=··pwm_backlight->period;
> +» unsigned·int·max·=·pwm_backlight->backlight.brightness_max;
> +
> +········duty·*=·brightness;
> +········do_div(duty,·max);

indent with tab instead of space here.

Marc

-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
Industrial Linux Solutions        | Phone: +49-231-2826-924     |
Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |


[-- Attachment #1.2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 455 bytes --]

[-- Attachment #2: Type: text/plain, Size: 149 bytes --]

_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox