[PATCH] backlight: enable max8925 backlight
Haojian Zhuang
haojian.zhuang at marvell.com
Fri Dec 18 10:01:45 EST 2009
Signed-off-by: Haojian Zhuang <haojian.zhuang at marvell.com>
---
drivers/video/backlight/Kconfig | 7 +
drivers/video/backlight/Makefile | 1 +
drivers/video/backlight/max8925_bl.c | 200 ++++++++++++++++++++++++++++++++++
3 files changed, 208 insertions(+), 0 deletions(-)
create mode 100644 drivers/video/backlight/max8925_bl.c
diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
index 09bfa96..3aa5b6c 100644
--- a/drivers/video/backlight/Kconfig
+++ b/drivers/video/backlight/Kconfig
@@ -212,6 +212,13 @@ config BACKLIGHT_DA903X
If you have a LCD backlight connected to the WLED output of DA9030
or DA9034 WLED output, say Y here to enable this driver.
+config BACKLIGHT_MAX8925
+ tristate "Backlight driver for MAX8925"
+ depends on BACKLIGHT_CLASS_DEVICE && MFD_MAX8925
+ help
+ If you have a LCD backlight connected to the WLED output of MAX8925
+ WLED output, say Y here to enable this driver.
+
config BACKLIGHT_MBP_NVIDIA
tristate "MacBook Pro Nvidia Backlight Driver"
depends on BACKLIGHT_CLASS_DEVICE && X86
diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
index 9a40554..5fc3daf 100644
--- a/drivers/video/backlight/Makefile
+++ b/drivers/video/backlight/Makefile
@@ -22,6 +22,7 @@ obj-$(CONFIG_BACKLIGHT_PROGEAR) += progear_bl.o
obj-$(CONFIG_BACKLIGHT_CARILLO_RANCH) += cr_bllcd.o
obj-$(CONFIG_BACKLIGHT_PWM) += pwm_bl.o
obj-$(CONFIG_BACKLIGHT_DA903X) += da903x_bl.o
+obj-$(CONFIG_BACKLIGHT_MAX8925) += max8925_bl.o
obj-$(CONFIG_BACKLIGHT_MBP_NVIDIA) += mbp_nvidia_bl.o
obj-$(CONFIG_BACKLIGHT_TOSA) += tosa_bl.o
obj-$(CONFIG_BACKLIGHT_SAHARA) += kb3886_bl.o
diff --git a/drivers/video/backlight/max8925_bl.c
b/drivers/video/backlight/max8925_bl.c
new file mode 100644
index 0000000..c267069
--- /dev/null
+++ b/drivers/video/backlight/max8925_bl.c
@@ -0,0 +1,200 @@
+/*
+ * Backlight driver for Maxim MAX8925
+ *
+ * Copyright (C) 2009 Marvell International Ltd.
+ * Haojian Zhuang <haojian.zhuang at marvell.com>
+ *
+ * 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/init.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/fb.h>
+#include <linux/i2c.h>
+#include <linux/backlight.h>
+#include <linux/mfd/max8925.h>
+
+#define MAX_BRIGHTNESS (0xff)
+#define MIN_BRIGHTNESS (0)
+
+#define LWX_FREQ(x) (((x - 601) / 100) & 0x7)
+
+struct max8925_backlight_data {
+ struct max8925_chip *chip;
+
+ int current_brightness;
+};
+
+static int max8925_backlight_set(struct backlight_device *bl, int brightness)
+{
+ struct max8925_backlight_data *data = bl_get_data(bl);
+ struct max8925_chip *chip = data->chip;
+ unsigned char value;
+ int ret;
+
+ if (brightness > MAX_BRIGHTNESS)
+ value = MAX_BRIGHTNESS;
+ else
+ value = brightness;
+
+ ret = max8925_reg_write(chip->i2c, MAX8925_WLED_CNTL, value);
+ if (ret < 0)
+ goto out;
+
+ if (!data->current_brightness && brightness)
+ /* enable WLED output */
+ ret = max8925_set_bits(chip->i2c, MAX8925_WLED_MODE_CNTL, 1, 1);
+ else if (!brightness)
+ /* disable WLED output */
+ ret = max8925_set_bits(chip->i2c, MAX8925_WLED_MODE_CNTL, 1, 0);
+ if (ret < 0)
+ goto out;
+ dev_dbg(chip->dev, "set brightness %d\n", value);
+ data->current_brightness = value;
+ return 0;
+out:
+ dev_dbg(chip->dev, "set brightness %d failure with return value:%d\n",
+ value, ret);
+ return ret;
+}
+
+static int max8925_backlight_update_status(struct backlight_device *bl)
+{
+ int brightness = bl->props.brightness;
+
+ if (bl->props.power != FB_BLANK_UNBLANK)
+ brightness = 0;
+
+ if (bl->props.fb_blank != FB_BLANK_UNBLANK)
+ brightness = 0;
+
+ if (bl->props.state & BL_CORE_SUSPENDED)
+ brightness = 0;
+
+ return max8925_backlight_set(bl, brightness);
+}
+
+static int max8925_backlight_get_brightness(struct backlight_device *bl)
+{
+ struct max8925_backlight_data *data = bl_get_data(bl);
+ struct max8925_chip *chip = data->chip;
+ int ret;
+
+ ret = max8925_reg_read(chip->i2c, MAX8925_WLED_CNTL);
+ if (ret < 0)
+ return -EINVAL;
+ data->current_brightness = ret;
+ dev_dbg(chip->dev, "get brightness %d\n", data->current_brightness);
+ return ret;
+}
+
+static struct backlight_ops max8925_backlight_ops = {
+ .options = BL_CORE_SUSPENDRESUME,
+ .update_status = max8925_backlight_update_status,
+ .get_brightness = max8925_backlight_get_brightness,
+};
+
+static int __devinit max8925_backlight_probe(struct platform_device *pdev)
+{
+ struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
+ struct max8925_platform_data *max8925_pdata;
+ struct max8925_backlight_pdata *pdata = NULL;
+ struct max8925_backlight_data *data;
+ struct backlight_device *bl;
+ struct resource *res;
+ char name[MAX8925_NAME_SIZE];
+ unsigned char value;
+ int ret;
+
+ res = platform_get_resource(pdev, IORESOURCE_IO, 0);
+ if (res == NULL) {
+ dev_err(&pdev->dev, "No I/O resource!\n");
+ return -EINVAL;
+ }
+
+ if (pdev->dev.parent->platform_data) {
+ max8925_pdata = pdev->dev.parent->platform_data;
+ pdata = max8925_pdata->backlight;
+ }
+
+ if (!pdata) {
+ dev_err(&pdev->dev, "platform data isn't assigned to "
+ "backlight\n");
+ return -EINVAL;
+ }
+
+ data = kzalloc(sizeof(struct max8925_backlight_data), GFP_KERNEL);
+ if (data == NULL)
+ return -ENOMEM;
+ strncpy(name, res->name, MAX8925_NAME_SIZE);
+ data->chip = chip;
+ data->current_brightness = 0;
+
+ bl = backlight_device_register(name, &pdev->dev, data,
+ &max8925_backlight_ops);
+ if (IS_ERR(bl)) {
+ dev_err(&pdev->dev, "failed to register backlight\n");
+ kfree(data);
+ return PTR_ERR(bl);
+ }
+ bl->props.max_brightness = MAX_BRIGHTNESS;
+ bl->props.brightness = MAX_BRIGHTNESS;
+
+ platform_set_drvdata(pdev, bl);
+
+ value = 0;
+ if (pdata->lxw_scl)
+ value |= (1 << 7);
+ if (pdata->lxw_freq)
+ value |= (LWX_FREQ(pdata->lxw_freq) << 4);
+ if (pdata->dual_string)
+ value |= (1 << 1);
+ ret = max8925_set_bits(chip->i2c, MAX8925_WLED_MODE_CNTL, 0xfe, value);
+ if (ret < 0)
+ goto out;
+
+ backlight_update_status(bl);
+ return 0;
+out:
+ kfree(data);
+ return ret;
+}
+
+static int __devexit max8925_backlight_remove(struct platform_device *pdev)
+{
+ struct backlight_device *bl = platform_get_drvdata(pdev);
+ struct max8925_backlight_data *data = bl_get_data(bl);
+
+ backlight_device_unregister(bl);
+ kfree(data);
+ return 0;
+}
+
+static struct platform_driver max8925_backlight_driver = {
+ .driver = {
+ .name = "max8925-backlight",
+ .owner = THIS_MODULE,
+ },
+ .probe = max8925_backlight_probe,
+ .remove = __devexit_p(max8925_backlight_remove),
+};
+
+static int __init max8925_backlight_init(void)
+{
+ return platform_driver_register(&max8925_backlight_driver);
+}
+module_init(max8925_backlight_init);
+
+static void __exit max8925_backlight_exit(void)
+{
+ platform_driver_unregister(&max8925_backlight_driver);
+};
+module_exit(max8925_backlight_exit);
+
+MODULE_DESCRIPTION("Backlight Driver for Maxim MAX8925");
+MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang at marvell.com>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:max8925-backlight");
--
1.5.6.5
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