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Subject[PATCH 4/4] backlight: add LM3533 backlight driver
Date
Add sub-driver for the backlights in National Semiconductor / TI LM3533
lighting power chips.

The chip provides 256 brightness levels and ambient-light-sensor and pwm
input control.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
---
drivers/video/backlight/Kconfig | 12 +
drivers/video/backlight/Makefile | 1 +
drivers/video/backlight/lm3533_bl.c | 432 +++++++++++++++++++++++++++++++++++
3 files changed, 445 insertions(+), 0 deletions(-)
create mode 100644 drivers/video/backlight/lm3533_bl.c
diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
index af16884..45455e7 100644
--- a/drivers/video/backlight/Kconfig
+++ b/drivers/video/backlight/Kconfig
@@ -184,6 +184,18 @@ config BACKLIGHT_GENERIC
known as the Corgi backlight driver. If you have a Sharp Zaurus
SL-C7xx, SL-Cxx00 or SL-6000x say y.

+config BACKLIGHT_LM3533
+ tristate "Backlight Driver for LM3533"
+ depends on BACKLIGHT_CLASS_DEVICE
+ depends on MFD_LM3533
+ help
+ Say Y to enable the backlight driver for National Semiconductor / TI
+ LM3533 Lighting Power chips.
+
+ The backlights can be controlled directly, through PWM input, or by
+ the on-chip ambient light sensor. The chip supports 256 brightness
+ levels.
+
config BACKLIGHT_LOCOMO
tristate "Sharp LOCOMO LCD/Backlight Driver"
depends on SHARP_LOCOMO
diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
index 36855ae..a2ac9cf 100644
--- a/drivers/video/backlight/Makefile
+++ b/drivers/video/backlight/Makefile
@@ -21,6 +21,7 @@ obj-$(CONFIG_BACKLIGHT_EP93XX) += ep93xx_bl.o
obj-$(CONFIG_BACKLIGHT_GENERIC) += generic_bl.o
obj-$(CONFIG_BACKLIGHT_HP700) += jornada720_bl.o
obj-$(CONFIG_BACKLIGHT_HP680) += hp680_bl.o
+obj-$(CONFIG_BACKLIGHT_LM3533) += lm3533_bl.o
obj-$(CONFIG_BACKLIGHT_LOCOMO) += locomolcd.o
obj-$(CONFIG_BACKLIGHT_LP855X) += lp855x_bl.o
obj-$(CONFIG_BACKLIGHT_OMAP1) += omap1_bl.o
diff --git a/drivers/video/backlight/lm3533_bl.c b/drivers/video/backlight/lm3533_bl.c
new file mode 100644
index 0000000..4217e1f
--- /dev/null
+++ b/drivers/video/backlight/lm3533_bl.c
@@ -0,0 +1,432 @@
+/*
+ * lm3533-bl.c -- LM3533 Backlight driver
+ *
+ * Copyright (C) 2011-2012 Texas Instruments
+ *
+ * Author: Johan Hovold <jhovold@gmail.com>
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/backlight.h>
+#include <linux/fb.h>
+#include <linux/slab.h>
+
+#include <linux/mfd/lm3533.h>
+
+
+#define LM3533_HVCTRLBANK_COUNT 2
+#define LM3533_BL_MAX_BRIGHTNESS 255
+
+#define LM3533_REG_CTRLBANK_AB_BCONF 0x1a
+
+
+struct lm3533_bl {
+ struct lm3533 *lm3533;
+ struct lm3533_ctrlbank cb;
+ struct backlight_device *bd;
+ int id;
+};
+
+
+static inline int lm3533_bl_get_ctrlbank_id(struct lm3533_bl *bl)
+{
+ return bl->id;
+}
+
+static int lm3533_bl_update_status(struct backlight_device *bd)
+{
+ struct lm3533_bl *bl = bl_get_data(bd);
+ int brightness = bd->props.brightness;
+
+ if (bd->props.power != FB_BLANK_UNBLANK)
+ brightness = 0;
+ if (bd->props.fb_blank != FB_BLANK_UNBLANK)
+ brightness = 0;
+
+ return lm3533_ctrlbank_set_brightness(&bl->cb, (u8)brightness);
+}
+
+static int lm3533_bl_get_brightness(struct backlight_device *bd)
+{
+ struct lm3533_bl *bl = bl_get_data(bd);
+ u8 val;
+ int ret;
+
+ ret = lm3533_ctrlbank_get_brightness(&bl->cb, &val);
+ if (ret)
+ return ret;
+
+ return val;
+}
+
+static const struct backlight_ops lm3533_bl_ops = {
+ .get_brightness = lm3533_bl_get_brightness,
+ .update_status = lm3533_bl_update_status,
+};
+
+static ssize_t show_id(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct lm3533_bl *bl = dev_get_drvdata(dev);
+
+ return scnprintf(buf, PAGE_SIZE, "%d\n", bl->id);
+}
+
+/*
+ * ALS settings:
+ *
+ * 0 - ALS disabled
+ * 1 - ALS mapper 1 (backlight 0)
+ * 2 - ALS mapper 2 (backlight 1)
+ */
+static ssize_t show_als(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct lm3533_bl *bl = dev_get_drvdata(dev);
+ int ctrlbank = lm3533_bl_get_ctrlbank_id(bl);
+ u8 val;
+ u8 mask;
+ int als;
+ int ret;
+
+ ret = lm3533_read(bl->lm3533, LM3533_REG_CTRLBANK_AB_BCONF, &val);
+ if (ret)
+ return ret;
+
+ mask = 2 * ctrlbank;
+ als = val & mask;
+ if (als)
+ als = ctrlbank + 1;
+
+ return scnprintf(buf, PAGE_SIZE, "%d\n", als);
+}
+
+static ssize_t store_als(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ struct lm3533_bl *bl = dev_get_drvdata(dev);
+ int ctrlbank = lm3533_bl_get_ctrlbank_id(bl);
+ int als;
+ u8 val;
+ u8 mask;
+ int ret;
+
+ if (kstrtoint(buf, 0, &als))
+ return -EINVAL;
+
+ if (als != 0 && (als != ctrlbank + 1))
+ return -EINVAL;
+
+ mask = 1 << (2 * ctrlbank);
+
+ if (als)
+ val = mask;
+ else
+ val = 0;
+
+ ret = lm3533_update(bl->lm3533, LM3533_REG_CTRLBANK_AB_BCONF, val,
+ mask);
+ if (ret)
+ return ret;
+
+ return len;
+}
+
+static ssize_t show_linear(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct lm3533_bl *bl = dev_get_drvdata(dev);
+ u8 val;
+ u8 mask;
+ int linear;
+ int ret;
+
+ ret = lm3533_read(bl->lm3533, LM3533_REG_CTRLBANK_AB_BCONF, &val);
+ if (ret)
+ return ret;
+
+ mask = 1 << (2 * lm3533_bl_get_ctrlbank_id(bl) + 1);
+
+ if (val & mask)
+ linear = 1;
+ else
+ linear = 0;
+
+ return scnprintf(buf, PAGE_SIZE, "%x\n", linear);
+}
+
+static ssize_t store_linear(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ struct lm3533_bl *bl = dev_get_drvdata(dev);
+ unsigned long linear;
+ u8 mask;
+ u8 val;
+ int ret;
+
+ if (kstrtoul(buf, 0, &linear))
+ return -EINVAL;
+
+ mask = 1 << (2 * lm3533_bl_get_ctrlbank_id(bl) + 1);
+
+ if (linear)
+ val = mask;
+ else
+ val = 0;
+
+ ret = lm3533_update(bl->lm3533, LM3533_REG_CTRLBANK_AB_BCONF, val,
+ mask);
+ if (ret)
+ return ret;
+
+ return len;
+}
+
+#define show_ctrlbank_attr(_name) \
+static ssize_t show_##_name(struct device *dev, \
+ struct device_attribute *attr, \
+ char *buf) \
+{ \
+ struct lm3533_bl *bl = dev_get_drvdata(dev); \
+ u8 val; \
+ int ret; \
+ \
+ ret = lm3533_ctrlbank_get_##_name(&bl->cb, &val); \
+ if (ret) \
+ return ret; \
+ \
+ return scnprintf(buf, PAGE_SIZE, "%d\n", val); \
+}
+
+#define store_ctrlbank_attr(_name) \
+static ssize_t store_##_name(struct device *dev, \
+ struct device_attribute *attr, \
+ const char *buf, size_t len) \
+{ \
+ struct lm3533_bl *bl = dev_get_drvdata(dev); \
+ u8 val; \
+ int ret; \
+ \
+ if (kstrtou8(buf, 0, &val)) \
+ return -EINVAL; \
+ \
+ ret = lm3533_ctrlbank_set_##_name(&bl->cb, val); \
+ if (ret) \
+ return ret; \
+ \
+ return len; \
+}
+
+show_ctrlbank_attr(max_current);
+store_ctrlbank_attr(max_current);
+show_ctrlbank_attr(pwm);
+store_ctrlbank_attr(pwm);
+
+static LM3533_ATTR_RW(als);
+static LM3533_ATTR_RO(id);
+static LM3533_ATTR_RW(linear);
+static LM3533_ATTR_RW(max_current);
+static LM3533_ATTR_RW(pwm);
+
+static struct attribute *lm3533_bl_attributes[] = {
+ &dev_attr_als.attr,
+ &dev_attr_id.attr,
+ &dev_attr_linear.attr,
+ &dev_attr_max_current.attr,
+ &dev_attr_pwm.attr,
+ NULL,
+};
+
+static mode_t lm3533_bl_attr_is_visible(struct kobject *kobj,
+ struct attribute *attr, int n)
+{
+ struct device *dev = container_of(kobj, struct device, kobj);
+ struct lm3533_bl *bl = dev_get_drvdata(dev);
+ mode_t mode = attr->mode;
+
+ if (attr == &dev_attr_als.attr) {
+ if (!bl->lm3533->have_als)
+ mode = 0;
+ }
+
+ return mode;
+};
+
+static struct attribute_group lm3533_bl_attribute_group = {
+ .is_visible = lm3533_bl_attr_is_visible,
+ .attrs = lm3533_bl_attributes
+};
+
+static int __devinit lm3533_bl_setup(struct lm3533_bl *bl,
+ struct lm3533_bl_platform_data *pdata)
+{
+ int ret;
+
+ ret = lm3533_ctrlbank_set_max_current(&bl->cb, pdata->max_current);
+ if (ret)
+ return ret;
+
+ return lm3533_ctrlbank_set_pwm(&bl->cb, pdata->pwm);
+}
+
+static int __devinit lm3533_bl_probe(struct platform_device *pdev)
+{
+ struct lm3533 *lm3533;
+ struct lm3533_bl_platform_data *pdata;
+ struct lm3533_bl *bl;
+ struct backlight_device *bd;
+ struct backlight_properties props;
+ int ret;
+
+ dev_dbg(&pdev->dev, "%s\n", __func__);
+
+ lm3533 = dev_get_drvdata(pdev->dev.parent);
+ if (!lm3533)
+ return -EINVAL;
+
+ pdata = pdev->dev.platform_data;
+ if (!pdata) {
+ dev_err(&pdev->dev, "no platform data\n");
+ return -EINVAL;
+ }
+
+ if (pdev->id < 0 || pdev->id >= LM3533_HVCTRLBANK_COUNT) {
+ dev_err(&pdev->dev, "illegal backlight id %d\n", pdev->id);
+ return -EINVAL;
+ }
+
+ bl = kzalloc(sizeof(*bl), GFP_KERNEL);
+ if (!bl) {
+ dev_err(&pdev->dev,
+ "failed to allocate memory for backlight\n");
+ return -ENOMEM;
+ }
+
+ bl->lm3533 = lm3533;
+ bl->id = pdev->id;
+
+ bl->cb.lm3533 = lm3533;
+ bl->cb.id = lm3533_bl_get_ctrlbank_id(bl);
+ bl->cb.dev = NULL; /* until registered */
+
+ memset(&props, 0, sizeof(props));
+ props.type = BACKLIGHT_RAW;
+ props.max_brightness = LM3533_BL_MAX_BRIGHTNESS;
+ props.brightness = pdata->default_brightness;
+ bd = backlight_device_register(pdata->name, pdev->dev.parent, bl,
+ &lm3533_bl_ops, &props);
+ if (IS_ERR(bd)) {
+ dev_err(&pdev->dev, "failed to register backlight device\n");
+ ret = PTR_ERR(bd);
+ goto err_free;
+ }
+
+ bl->bd = bd;
+ bl->cb.dev = &bl->bd->dev;
+
+ platform_set_drvdata(pdev, bl);
+
+ ret = sysfs_create_group(&bd->dev.kobj, &lm3533_bl_attribute_group);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed to create sysfs attributes\n");
+ goto err_unregister;
+ }
+
+ backlight_update_status(bd);
+
+ ret = lm3533_bl_setup(bl, pdata);
+ if (ret)
+ goto err_sysfs_remove;
+
+ ret = lm3533_ctrlbank_enable(&bl->cb);
+ if (ret)
+ goto err_sysfs_remove;
+
+ return 0;
+
+err_sysfs_remove:
+ sysfs_remove_group(&bd->dev.kobj, &lm3533_bl_attribute_group);
+err_unregister:
+ backlight_device_unregister(bd);
+err_free:
+ kfree(bl);
+
+ return ret;
+}
+
+static int __devexit lm3533_bl_remove(struct platform_device *pdev)
+{
+ struct lm3533_bl *bl = platform_get_drvdata(pdev);
+ struct backlight_device *bd = bl->bd;
+
+ dev_dbg(&bd->dev, "%s\n", __func__);
+
+ bd->props.power = FB_BLANK_POWERDOWN;
+ bd->props.brightness = 0;
+
+ lm3533_ctrlbank_disable(&bl->cb);
+ sysfs_remove_group(&bd->dev.kobj, &lm3533_bl_attribute_group);
+ backlight_device_unregister(bd);
+ kfree(bl);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int lm3533_bl_suspend(struct platform_device *pdev, pm_message_t state)
+{
+ struct lm3533_bl *bl = platform_get_drvdata(pdev);
+
+ dev_dbg(&pdev->dev, "%s\n", __func__);
+
+ return lm3533_ctrlbank_disable(&bl->cb);
+}
+
+static int lm3533_bl_resume(struct platform_device *pdev)
+{
+ struct lm3533_bl *bl = platform_get_drvdata(pdev);
+
+ dev_dbg(&pdev->dev, "%s\n", __func__);
+
+ return lm3533_ctrlbank_enable(&bl->cb);
+}
+#else
+#define lm3533_bl_suspend NULL
+#define lm3533_bl_resume NULL
+#endif
+
+static void lm3533_bl_shutdown(struct platform_device *pdev)
+{
+ struct lm3533_bl *bl = platform_get_drvdata(pdev);
+
+ dev_dbg(&pdev->dev, "%s\n", __func__);
+
+ lm3533_ctrlbank_disable(&bl->cb);
+}
+
+static struct platform_driver lm3533_bl_driver = {
+ .driver = {
+ .name = "lm3533-backlight",
+ .owner = THIS_MODULE,
+ },
+ .probe = lm3533_bl_probe,
+ .remove = __devexit_p(lm3533_bl_remove),
+ .shutdown = lm3533_bl_shutdown,
+ .suspend = lm3533_bl_suspend,
+ .resume = lm3533_bl_resume,
+};
+module_platform_driver(lm3533_bl_driver);
+
+MODULE_AUTHOR("Johan Hovold <jhovold@gmail.com>");
+MODULE_DESCRIPTION("LM3533 Backlight driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:lm3533-backlight");
--
1.7.8.5


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