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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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