backlight/mfd: Add pcf50633 backlight driver
authorLars-Peter Clausen <lars@metafoo.de>
Mon, 2 Nov 2009 18:54:35 +0000 (19:54 +0100)
committerLars-Peter Clausen <lars@metafoo.de>
Mon, 17 May 2010 17:59:40 +0000 (19:59 +0200)
This patch adds a backlight driver controling the pcf50633 led converter.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
drivers/mfd/pcf50633-core.c
drivers/video/backlight/Kconfig
drivers/video/backlight/Makefile
drivers/video/backlight/pcf50633-backlight.c [new file with mode: 0644]
include/linux/mfd/pcf50633/backlight.h [new file with mode: 0644]
include/linux/mfd/pcf50633/core.h

index 64d490c..977a422 100644 (file)
@@ -620,6 +620,9 @@ static int __devinit pcf50633_probe(struct i2c_client *client,
                                                &pcf->mbc_pdev);
        pcf50633_client_dev_register(pcf, "pcf50633-adc",
                                                &pcf->adc_pdev);
+       pcf50633_client_dev_register(pcf, "pcf50633-backlight",
+                                               &pcf->bl_pdev);
+
 
        for (i = 0; i < PCF50633_NUM_REGULATORS; i++) {
                struct platform_device *pdev;
index c025c84..6aadc00 100644 (file)
@@ -282,3 +282,9 @@ 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.
index 09d1f14..8b714c1 100644 (file)
@@ -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 (file)
index 0000000..5b72089
--- /dev/null
@@ -0,0 +1,189 @@
+/*
+ *  Copyright (C) 2009, Lars-Peter Clausen <lars@metafoo.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 actuall 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 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 pcf50633_platform_data *pcf50633_data = pdev->dev.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 don't
+        * 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@metafoo.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 (file)
index 0000000..9d3646a
--- /dev/null
@@ -0,0 +1,44 @@
+/*
+ *  Copyright (C) 2009, Lars-Peter Clausen <lars@metafoo.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:       Brightness to be used after the driver has been
+                             probed. Valid range 0-63.
+* @default_brightness_limit: Brightness limit to be used after the driver has
+*                            been probed. This is usfull when it is not known
+*                            how much power is available for the backlight
+*                            during probe. Valid range 0-63
+* @ramp_time:                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
+
index 3398bd9..ad411a7 100644 (file)
@@ -18,6 +18,7 @@
 #include <linux/regulator/driver.h>
 #include <linux/regulator/machine.h>
 #include <linux/power_supply.h>
+#include <linux/mfd/pcf50633/backlight.h>
 
 struct pcf50633;
 
@@ -43,6 +44,8 @@ struct pcf50633_platform_data {
        void (*force_shutdown)(struct pcf50633 *);
 
        u8 resumers[5];
+
+       struct pcf50633_bl_platform_data *backlight_data;
 };
 
 struct pcf50633_irq {
@@ -152,6 +155,7 @@ struct pcf50633 {
        struct platform_device *mbc_pdev;
        struct platform_device *adc_pdev;
        struct platform_device *input_pdev;
+       struct platform_device *bl_pdev;
        struct platform_device *regulator_pdev[PCF50633_NUM_REGULATORS];
 };