]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commitdiff
backlight: add LM3533 backlight driver
authorJohan Hovold <jhovold@gmail.com>
Tue, 29 May 2012 22:07:14 +0000 (15:07 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 29 May 2012 23:22:29 +0000 (16:22 -0700)
Add sub-driver for the backlights on National Semiconductor / TI LM3533
lighting power chips.

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

[akpm@linux-foundation.org: fix warning]
[akpm@linux-foundation.org: fix the type of `mode']
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Rob Landley <rob@landley.net>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Cc: Jonathan Cameron <jic23@cam.ac.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Documentation/ABI/testing/sysfs-class-backlight-driver-lm3533 [new file with mode: 0644]
drivers/video/backlight/Kconfig
drivers/video/backlight/Makefile
drivers/video/backlight/lm3533_bl.c [new file with mode: 0644]

diff --git a/Documentation/ABI/testing/sysfs-class-backlight-driver-lm3533 b/Documentation/ABI/testing/sysfs-class-backlight-driver-lm3533
new file mode 100644 (file)
index 0000000..77cf7ac
--- /dev/null
@@ -0,0 +1,48 @@
+What:          /sys/class/backlight/<backlight>/als_channel
+Date:          May 2012
+KernelVersion: 3.5
+Contact:       Johan Hovold <jhovold@gmail.com>
+Description:
+               Get the ALS output channel used as input in
+               ALS-current-control mode (0, 1), where
+
+               0 - out_current0 (backlight 0)
+               1 - out_current1 (backlight 1)
+
+What:          /sys/class/backlight/<backlight>/als_en
+Date:          May 2012
+KernelVersion: 3.5
+Contact:       Johan Hovold <jhovold@gmail.com>
+Description:
+               Enable ALS-current-control mode (0, 1).
+
+What:          /sys/class/backlight/<backlight>/id
+Date:          April 2012
+KernelVersion: 3.5
+Contact:       Johan Hovold <jhovold@gmail.com>
+Description:
+               Get the id of this backlight (0, 1).
+
+What:          /sys/class/backlight/<backlight>/linear
+Date:          April 2012
+KernelVersion: 3.5
+Contact:       Johan Hovold <jhovold@gmail.com>
+Description:
+               Set the brightness-mapping mode (0, 1), where
+
+               0 - exponential mode
+               1 - linear mode
+
+What:          /sys/class/backlight/<backlight>/pwm
+Date:          April 2012
+KernelVersion: 3.5
+Contact:       Johan Hovold <jhovold@gmail.com>
+Description:
+               Set the PWM-input control mask (5 bits), where
+
+               bit 5 - PWM-input enabled in Zone 4
+               bit 4 - PWM-input enabled in Zone 3
+               bit 3 - PWM-input enabled in Zone 2
+               bit 2 - PWM-input enabled in Zone 1
+               bit 1 - PWM-input enabled in Zone 0
+               bit 0 - PWM-input enabled
index af16884491edf45cf3105f79e340a6b912757541..fa2b03750316b175f36f72d6f7cf8cf8a69bc375 100644 (file)
@@ -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 ambient-light-sensor interface. The chip supports 256 brightness
+         levels.
+
 config BACKLIGHT_LOCOMO
        tristate "Sharp LOCOMO LCD/Backlight Driver"
        depends on SHARP_LOCOMO
index 36855ae887d6ae9f56a85a0b02b24a3afa271c83..a2ac9cfbaf6bf1869e1c2b020b597952d4a7633a 100644 (file)
@@ -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 (file)
index 0000000..bebeb63
--- /dev/null
@@ -0,0 +1,423 @@
+/*
+ * 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);
+}
+
+static ssize_t show_als_channel(struct device *dev,
+                               struct device_attribute *attr, char *buf)
+{
+       struct lm3533_bl *bl = dev_get_drvdata(dev);
+       unsigned channel = lm3533_bl_get_ctrlbank_id(bl);
+
+       return scnprintf(buf, PAGE_SIZE, "%u\n", channel);
+}
+
+static ssize_t show_als_en(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;
+       bool enable;
+       int ret;
+
+       ret = lm3533_read(bl->lm3533, LM3533_REG_CTRLBANK_AB_BCONF, &val);
+       if (ret)
+               return ret;
+
+       mask = 1 << (2 * ctrlbank);
+       enable = val & mask;
+
+       return scnprintf(buf, PAGE_SIZE, "%d\n", enable);
+}
+
+static ssize_t store_als_en(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 enable;
+       u8 val;
+       u8 mask;
+       int ret;
+
+       if (kstrtoint(buf, 0, &enable))
+               return -EINVAL;
+
+       mask = 1 << (2 * ctrlbank);
+
+       if (enable)
+               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;
+}
+
+static ssize_t show_pwm(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_pwm(&bl->cb, &val);
+       if (ret)
+               return ret;
+
+       return scnprintf(buf, PAGE_SIZE, "%u\n", val);
+}
+
+static ssize_t store_pwm(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_pwm(&bl->cb, val);
+       if (ret)
+               return ret;
+
+       return len;
+}
+
+static LM3533_ATTR_RO(als_channel);
+static LM3533_ATTR_RW(als_en);
+static LM3533_ATTR_RO(id);
+static LM3533_ATTR_RW(linear);
+static LM3533_ATTR_RW(pwm);
+
+static struct attribute *lm3533_bl_attributes[] = {
+       &dev_attr_als_channel.attr,
+       &dev_attr_als_en.attr,
+       &dev_attr_id.attr,
+       &dev_attr_linear.attr,
+       &dev_attr_pwm.attr,
+       NULL,
+};
+
+static umode_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);
+       umode_t mode = attr->mode;
+
+       if (attr == &dev_attr_als_channel.attr ||
+                                       attr == &dev_attr_als_en.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");