1 files changed, 177 insertions, 0 deletions

diff --git a/drivers/video/backlight/tegra_pwm_bl.c b/drivers/video/backlight/tegra_pwm_bl.c
new file mode 100644
index 00000000000..4be691c54d3
--- /dev/null
+++ b/drivers/video/backlight/tegra_pwm_bl.c
@@ -0,0 +1,177 @@
+/*
+ * linux/drivers/video/backlight/tegra_pwm_bl.c
+ *
+ * Tegra pwm backlight driver
+ *
+ * Copyright (C) 2011 NVIDIA Corporation
+ * Author: Renuka Apte <rapte@nvidia.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/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/fb.h>
+#include <linux/backlight.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/tegra_pwm_bl.h>
+#include <mach/dc.h>
+
+struct tegra_pwm_bl_data {
+        struct device *dev;
+        int which_dc;
+        int (*notify)(struct device *, int brightness);
+        struct tegra_dc_pwm_params params;
+        int (*check_fb)(struct device *dev, struct fb_info *info);
+};
+
+static int tegra_pwm_backlight_update_status(struct backlight_device *bl)
+{
+        struct tegra_pwm_bl_data *tbl = dev_get_drvdata(&bl->dev);
+        int brightness = bl->props.brightness;
+        int max = bl->props.max_brightness;
+        struct tegra_dc *dc;
+
+        if (bl->props.power != FB_BLANK_UNBLANK)
+                brightness = 0;
+
+        if (bl->props.fb_blank != FB_BLANK_UNBLANK)
+                brightness = 0;
+
+        if (tbl->notify)
+                brightness = tbl->notify(tbl->dev, brightness);
+
+        if (brightness > max)
+                dev_err(&bl->dev, "Invalid brightness value: %d max: %d\n",
+                brightness, max);
+
+#if defined(CONFIG_ARCH_TEGRA_2x_SOC)
+        /* map API brightness range from (0~255) to hw range (0~128) */
+        tbl->params.duty_cycle = (brightness * 128) / 255;
+#else
+        tbl->params.duty_cycle = brightness & 0xFF;
+#endif
+
+        /* Call tegra display controller function to update backlight */
+        dc = tegra_dc_get_dc(tbl->which_dc);
+        if (dc)
+                tegra_dc_config_pwm(dc, &tbl->params);
+        else
+                dev_err(&bl->dev, "tegra display controller not available\n");
+
+        return 0;
+}
+
+static int tegra_pwm_backlight_get_brightness(struct backlight_device *bl)
+{
+        return bl->props.brightness;
+}
+
+static int tegra_pwm_backlight_check_fb(struct backlight_device *bl,
+                                        struct fb_info *info)
+{
+        struct tegra_pwm_bl_data *tbl = dev_get_drvdata(&bl->dev);
+        return !tbl->check_fb || tbl->check_fb(tbl->dev, info);
+}
+
+static const struct backlight_ops tegra_pwm_backlight_ops = {
+        .update_status  = tegra_pwm_backlight_update_status,
+        .get_brightness = tegra_pwm_backlight_get_brightness,
+        .check_fb       = tegra_pwm_backlight_check_fb,
+};
+
+static int tegra_pwm_backlight_probe(struct platform_device *pdev)
+{
+        struct backlight_properties props;
+        struct platform_tegra_pwm_backlight_data *data;
+        struct backlight_device *bl;
+        struct tegra_pwm_bl_data *tbl;
+        int ret;
+
+        data = pdev->dev.platform_data;
+        if (!data) {
+                dev_err(&pdev->dev, "failed to find platform data\n");
+                return -EINVAL;
+        }
+
+        tbl = kzalloc(sizeof(*tbl), GFP_KERNEL);
+        if (!tbl) {
+                dev_err(&pdev->dev, "no memory for state\n");
+                ret = -ENOMEM;
+                goto err_alloc;
+        }
+
+        tbl->dev = &pdev->dev;
+        tbl->which_dc = data->which_dc;
+        tbl->notify = data->notify;
+        tbl->check_fb = data->check_fb;
+        tbl->params.which_pwm = data->which_pwm;
+        tbl->params.gpio_conf_to_sfio = data->gpio_conf_to_sfio;
+        tbl->params.switch_to_sfio = data->switch_to_sfio;
+        tbl->params.period = data->period;
+        tbl->params.clk_div = data->clk_div;
+        tbl->params.clk_select = data->clk_select;
+
+        memset(&props, 0, sizeof(struct backlight_properties));
+        props.type = BACKLIGHT_RAW;
+        props.max_brightness = data->max_brightness;
+        bl = backlight_device_register(dev_name(&pdev->dev), &pdev->dev, tbl,
+                        &tegra_pwm_backlight_ops, &props);
+        if (IS_ERR(bl)) {
+                dev_err(&pdev->dev, "failed to register backlight\n");
+                ret = PTR_ERR(bl);
+                goto err_bl;
+        }
+
+        bl->props.brightness = data->dft_brightness;
+        backlight_update_status(bl);
+
+        platform_set_drvdata(pdev, bl);
+        return 0;
+
+err_bl:
+        kfree(tbl);
+err_alloc:
+        return ret;
+}
+
+static int tegra_pwm_backlight_remove(struct platform_device *pdev)
+{
+        struct backlight_device *bl = platform_get_drvdata(pdev);
+        struct tegra_pwm_bl_data *tbl = dev_get_drvdata(&bl->dev);
+
+        backlight_device_unregister(bl);
+        kfree(tbl);
+        return 0;
+}
+
+static struct platform_driver tegra_pwm_backlight_driver = {
+        .driver         = {
+                .name   = "tegra-pwm-bl",
+                .owner  = THIS_MODULE,
+        },
+        .probe          = tegra_pwm_backlight_probe,
+        .remove         = tegra_pwm_backlight_remove,
+};
+
+static int __init tegra_pwm_backlight_init(void)
+{
+        return platform_driver_register(&tegra_pwm_backlight_driver);
+}
+late_initcall(tegra_pwm_backlight_init);
+
+static void __exit tegra_pwm_backlight_exit(void)
+{
+        platform_driver_unregister(&tegra_pwm_backlight_driver);
+}
+module_exit(tegra_pwm_backlight_exit);
+
+MODULE_DESCRIPTION("Tegra PWM Backlight Driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:tegra-pwm-backlight");
+