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Message-Id: <1273625074-15312-2-git-send-email-lars@metafoo.de>
Date: Wed, 12 May 2010 02:44:32 +0200
From: Lars-Peter Clausen <lars@...afoo.de>
To: rpurdie@...ys.net
Cc: sameo@...ux.intel.com, linux-kernel@...r.kernel.org,
Lars-Peter Clausen <lars@...afoo.de>
Subject: [PATCH 1/3] backlight: Add pcf50633 backlight driver
This patch adds a backlight driver for controlling the pcf50633 LED module.
Signed-off-by: Lars-Peter Clausen <lars@...afoo.de>
---
drivers/video/backlight/Kconfig | 7 +
drivers/video/backlight/Makefile | 1 +
drivers/video/backlight/pcf50633-backlight.c | 190 ++++++++++++++++++++++++++
include/linux/mfd/pcf50633/backlight.h | 51 +++++++
4 files changed, 249 insertions(+), 0 deletions(-)
create mode 100644 drivers/video/backlight/pcf50633-backlight.c
create mode 100644 include/linux/mfd/pcf50633/backlight.h
diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
index 4dfb5f4..3e8e7f7 100644
--- a/drivers/video/backlight/Kconfig
+++ b/drivers/video/backlight/Kconfig
@@ -270,6 +270,13 @@ config BACKLIGHT_88PM860X
help
Say Y to enable the backlight driver for Marvell 88PM8606.
+config BACKLIGHT_PCF50633
+ tristate "Backlight driver for NXP PCF50633 MFD"
+ depends on BACKLIGHT_CLASS_DEVICE && MFD_PCF50633
+ help
+ If you have a backlight driven by a NXP PCF50633 MFD, say Y here to
+ enable its driver.
+
endif # BACKLIGHT_CLASS_DEVICE
endif # BACKLIGHT_LCD_SUPPORT
diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
index 09d1f14..8b714c1 100644
--- a/drivers/video/backlight/Makefile
+++ b/drivers/video/backlight/Makefile
@@ -31,4 +31,5 @@ obj-$(CONFIG_BACKLIGHT_WM831X) += wm831x_bl.o
obj-$(CONFIG_BACKLIGHT_ADX) += adx_bl.o
obj-$(CONFIG_BACKLIGHT_ADP5520) += adp5520_bl.o
obj-$(CONFIG_BACKLIGHT_88PM860X) += 88pm860x_bl.o
+obj-$(CONFIG_BACKLIGHT_PCF50633) += pcf50633-backlight.o
diff --git a/drivers/video/backlight/pcf50633-backlight.c b/drivers/video/backlight/pcf50633-backlight.c
new file mode 100644
index 0000000..3c424f7
--- /dev/null
+++ b/drivers/video/backlight/pcf50633-backlight.c
@@ -0,0 +1,190 @@
+/*
+ * Copyright (C) 2009-2010, Lars-Peter Clausen <lars@...afoo.de>
+ * PCF50633 backlight device driver
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+
+#include <linux/backlight.h>
+#include <linux/fb.h>
+
+#include <linux/mfd/pcf50633/core.h>
+#include <linux/mfd/pcf50633/backlight.h>
+
+struct pcf50633_bl {
+ struct pcf50633 *pcf;
+ struct backlight_device *bl;
+
+ unsigned int brightness;
+ unsigned int brightness_limit;
+};
+
+/*
+ * pcf50633_bl_set_brightness_limit
+ *
+ * Update the brightness limit for the pc50633 backlight. The actual brightness
+ * will not go above the limit. This is useful to limit power drain for example
+ * on low battery.
+ *
+ * @dev: Pointer to a pcf50633 device
+ * @limit: The brightness limit. Valid values are 0-63
+ */
+int pcf50633_bl_set_brightness_limit(struct pcf50633 *pcf, unsigned int limit)
+{
+ struct pcf50633_bl *pcf_bl = platform_get_drvdata(pcf->bl_pdev);
+
+ if (!pcf_bl)
+ return -ENODEV;
+
+ pcf_bl->brightness_limit = limit & 0x3f;
+ backlight_update_status(pcf_bl->bl);
+
+ return 0;
+}
+
+static int pcf50633_bl_update_status(struct backlight_device *bl)
+{
+ struct pcf50633_bl *pcf_bl = bl_get_data(bl);
+ unsigned int new_brightness;
+
+
+ if (bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK) ||
+ bl->props.power != FB_BLANK_UNBLANK)
+ new_brightness = 0;
+ else if (bl->props.brightness < pcf_bl->brightness_limit)
+ new_brightness = bl->props.brightness;
+ else
+ new_brightness = pcf_bl->brightness_limit;
+
+
+ if (pcf_bl->brightness == new_brightness)
+ return 0;
+
+ if (new_brightness) {
+ pcf50633_reg_write(pcf_bl->pcf, PCF50633_REG_LEDOUT,
+ new_brightness);
+ if (!pcf_bl->brightness)
+ pcf50633_reg_write(pcf_bl->pcf, PCF50633_REG_LEDENA, 1);
+ } else {
+ pcf50633_reg_write(pcf_bl->pcf, PCF50633_REG_LEDENA, 0);
+ }
+
+ pcf_bl->brightness = new_brightness;
+
+ return 0;
+}
+
+static int pcf50633_bl_get_brightness(struct backlight_device *bl)
+{
+ struct pcf50633_bl *pcf_bl = bl_get_data(bl);
+ return pcf_bl->brightness;
+}
+
+static const struct backlight_ops pcf50633_bl_ops = {
+ .get_brightness = pcf50633_bl_get_brightness,
+ .update_status = pcf50633_bl_update_status,
+ .options = BL_CORE_SUSPENDRESUME,
+};
+
+static int __devinit pcf50633_bl_probe(struct platform_device *pdev)
+{
+ int ret;
+ struct pcf50633_bl *pcf_bl;
+ struct device *parent = pdev->dev.parent;
+ struct pcf50633_platform_data *pcf50633_data = parent->platform_data;
+ struct pcf50633_bl_platform_data *pdata = pcf50633_data->backlight_data;
+ struct backlight_properties bl_props;
+
+ pcf_bl = kzalloc(sizeof(*pcf_bl), GFP_KERNEL);
+ if (!pcf_bl)
+ return -ENOMEM;
+
+ bl_props.max_brightness = 0x3f;
+ bl_props.power = FB_BLANK_UNBLANK;
+
+ if (pdata) {
+ bl_props.brightness = pdata->default_brightness;
+ pcf_bl->brightness_limit = pdata->default_brightness_limit;
+ } else {
+ bl_props.brightness = 0x3f;
+ pcf_bl->brightness_limit = 0x3f;
+ }
+
+ pcf_bl->pcf = dev_to_pcf50633(pdev->dev.parent);
+
+ pcf_bl->bl = backlight_device_register(pdev->name, &pdev->dev, pcf_bl,
+ &pcf50633_bl_ops, &bl_props);
+
+ if (IS_ERR(pcf_bl->bl)) {
+ ret = PTR_ERR(pcf_bl->bl);
+ goto err_free;
+ }
+
+ platform_set_drvdata(pdev, pcf_bl);
+
+ pcf50633_reg_write(pcf_bl->pcf, PCF50633_REG_LEDDIM, pdata->ramp_time);
+
+ /* Should be different from bl_props.brightness, so we do not exit
+ * update_status early the first time it's called */
+ pcf_bl->brightness = pcf_bl->bl->props.brightness + 1;
+
+ backlight_update_status(pcf_bl->bl);
+
+ return 0;
+
+err_free:
+ kfree(pcf_bl);
+
+ return ret;
+}
+
+static int __devexit pcf50633_bl_remove(struct platform_device *pdev)
+{
+ struct pcf50633_bl *pcf_bl = platform_get_drvdata(pdev);
+
+ backlight_device_unregister(pcf_bl->bl);
+
+ platform_set_drvdata(pdev, NULL);
+
+ kfree(pcf_bl);
+
+ return 0;
+}
+
+static struct platform_driver pcf50633_bl_driver = {
+ .probe = pcf50633_bl_probe,
+ .remove = __devexit_p(pcf50633_bl_remove),
+ .driver = {
+ .name = "pcf50633-backlight",
+ },
+};
+
+static int __init pcf50633_bl_init(void)
+{
+ return platform_driver_register(&pcf50633_bl_driver);
+}
+module_init(pcf50633_bl_init);
+
+static void __exit pcf50633_bl_exit(void)
+{
+ platform_driver_unregister(&pcf50633_bl_driver);
+}
+module_exit(pcf50633_bl_exit);
+
+MODULE_AUTHOR("Lars-Peter Clausen <lars@...afoo.de>");
+MODULE_DESCRIPTION("PCF50633 backlight driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:pcf50633-backlight");
diff --git a/include/linux/mfd/pcf50633/backlight.h b/include/linux/mfd/pcf50633/backlight.h
new file mode 100644
index 0000000..83747e2
--- /dev/null
+++ b/include/linux/mfd/pcf50633/backlight.h
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2009-2010, Lars-Peter Clausen <lars@...afoo.de>
+ * PCF50633 backlight device driver
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#ifndef __LINUX_MFD_PCF50633_BACKLIGHT
+#define __LINUX_MFD_PCF50633_BACKLIGHT
+
+/*
+* @default_brightness: Backlight brightness is initialized to this value
+*
+* Brightness to be used after the driver has been probed.
+* Valid range 0-63.
+*
+* @default_brightness_limit: The actual brightness is limited by this value
+*
+* Brightness limit to be used after the driver has been probed. This is useful
+* when it is not known how much power is available for the backlight during
+* probe.
+* Valid range 0-63. Can be changed later with pcf50633_bl_set_brightness_limit.
+*
+* @ramp_time: Display ramp time when changing brightness
+*
+* When changing the backlights brightness the change is not instant, instead
+* it fades smooth from one state to another. This value specifies how long
+* the fade should take. The lower the value the higher the fade time.
+* Valid range 0-255
+*/
+struct pcf50633_bl_platform_data {
+ unsigned int default_brightness;
+ unsigned int default_brightness_limit;
+ uint8_t ramp_time;
+};
+
+
+struct pcf50633;
+
+int pcf50633_bl_set_brightness_limit(struct pcf50633 *pcf, unsigned int limit);
+
+#endif
+
--
1.5.6.5
--
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