backlight: Add support for the Avionic Design Xanthos backlight device.

This patch adds support for the backlight device found on Avionic Design
Xanthos-based boards.

Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>

3 files changed, 187 insertions, 1 deletions

diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
index c0d4a536ea87..22a49944d98d 100644
--- a/drivers/video/backlight/Kconfig
+++ b/drivers/video/backlight/Kconfig
@@ -243,3 +243,11 @@ config BACKLIGHT_WM831X
         help
           If you have a backlight driven by the ISINK and DCDC of a
           WM831x PMIC say y to enable the backlight driver for it.
+
+config BACKLIGHT_ADX
+        tristate "Avionic Design Xanthos Backlight Driver"
+        depends on BACKLIGHT_CLASS_DEVICE && ARCH_PXA_ADX
+        default y
+        help
+          Say Y to enable the backlight driver on Avionic Design Xanthos-based
+          boards.
diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
index 0abc014215ba..a483709205ac 100644
--- a/drivers/video/backlight/Makefile
+++ b/drivers/video/backlight/Makefile
@@ -26,4 +26,4 @@ obj-$(CONFIG_BACKLIGHT_MBP_NVIDIA) += mbp_nvidia_bl.o
 obj-$(CONFIG_BACKLIGHT_TOSA)    += tosa_bl.o
 obj-$(CONFIG_BACKLIGHT_SAHARA)  += kb3886_bl.o
 obj-$(CONFIG_BACKLIGHT_WM831X)  += wm831x_bl.o
-
+obj-$(CONFIG_BACKLIGHT_ADX)    += adx_bl.o
diff --git a/drivers/video/backlight/adx_bl.c b/drivers/video/backlight/adx_bl.c
new file mode 100644
index 000000000000..2c3bdfc620b7
--- /dev/null
+++ b/drivers/video/backlight/adx_bl.c
@@ -0,0 +1,178 @@
+/*
+ * linux/drivers/video/backlight/adx.c
+ *
+ * Copyright (C) 2009 Avionic Design GmbH
+ *
+ * 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.
+ *
+ * Written by Thierry Reding <thierry.reding@avionic-design.de>
+ */
+
+#include <linux/backlight.h>
+#include <linux/fb.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+/* register definitions */
+#define ADX_BACKLIGHT_CONTROL           0x00
+#define ADX_BACKLIGHT_CONTROL_ENABLE    (1 << 0)
+#define ADX_BACKLIGHT_BRIGHTNESS        0x08
+#define ADX_BACKLIGHT_STATUS            0x10
+#define ADX_BACKLIGHT_ERROR             0x18
+
+struct adxbl {
+        void __iomem *base;
+};
+
+static int adx_backlight_update_status(struct backlight_device *bldev)
+{
+        struct adxbl *bl = bl_get_data(bldev);
+        u32 value;
+
+        value = bldev->props.brightness;
+        writel(value, bl->base + ADX_BACKLIGHT_BRIGHTNESS);
+
+        value = readl(bl->base + ADX_BACKLIGHT_CONTROL);
+
+        if (bldev->props.state & BL_CORE_FBBLANK)
+                value &= ~ADX_BACKLIGHT_CONTROL_ENABLE;
+        else
+                value |= ADX_BACKLIGHT_CONTROL_ENABLE;
+
+        writel(value, bl->base + ADX_BACKLIGHT_CONTROL);
+
+        return 0;
+}
+
+static int adx_backlight_get_brightness(struct backlight_device *bldev)
+{
+        struct adxbl *bl = bl_get_data(bldev);
+        u32 brightness;
+
+        brightness = readl(bl->base + ADX_BACKLIGHT_BRIGHTNESS);
+        return brightness & 0xff;
+}
+
+static int adx_backlight_check_fb(struct fb_info *fb)
+{
+        return 1;
+}
+
+static struct backlight_ops adx_backlight_ops = {
+        .options = 0,
+        .update_status = adx_backlight_update_status,
+        .get_brightness = adx_backlight_get_brightness,
+        .check_fb = adx_backlight_check_fb,
+};
+
+static int __devinit adx_backlight_probe(struct platform_device *pdev)
+{
+        struct backlight_device *bldev;
+        struct resource *res;
+        struct adxbl *bl;
+        int ret = 0;
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        if (!res) {
+                ret = -ENXIO;
+                goto out;
+        }
+
+        res = devm_request_mem_region(&pdev->dev, res->start,
+                        resource_size(res), res->name);
+        if (!res) {
+                ret = -ENXIO;
+                goto out;
+        }
+
+        bl = devm_kzalloc(&pdev->dev, sizeof(*bl), GFP_KERNEL);
+        if (!bl) {
+                ret = -ENOMEM;
+                goto out;
+        }
+
+        bl->base = devm_ioremap_nocache(&pdev->dev, res->start,
+                        resource_size(res));
+        if (!bl->base) {
+                ret = -ENXIO;
+                goto out;
+        }
+
+        bldev = backlight_device_register(dev_name(&pdev->dev), &pdev->dev, bl,
+                        &adx_backlight_ops);
+        if (!bldev) {
+                ret = -ENOMEM;
+                goto out;
+        }
+
+        bldev->props.max_brightness = 0xff;
+        bldev->props.brightness = 0xff;
+        bldev->props.power = FB_BLANK_UNBLANK;
+
+        platform_set_drvdata(pdev, bldev);
+
+out:
+        return ret;
+}
+
+static int __devexit adx_backlight_remove(struct platform_device *pdev)
+{
+        struct backlight_device *bldev;
+        int ret = 0;
+
+        bldev = platform_get_drvdata(pdev);
+        bldev->props.power = FB_BLANK_UNBLANK;
+        bldev->props.brightness = 0xff;
+        backlight_update_status(bldev);
+        backlight_device_unregister(bldev);
+        platform_set_drvdata(pdev, NULL);
+
+        return ret;
+}
+
+#ifdef CONFIG_PM
+static int adx_backlight_suspend(struct platform_device *pdev,
+                pm_message_t state)
+{
+        return 0;
+}
+
+static int adx_backlight_resume(struct platform_device *pdev)
+{
+        return 0;
+}
+#else
+#define adx_backlight_suspend NULL
+#define adx_backlight_resume NULL
+#endif
+
+static struct platform_driver adx_backlight_driver = {
+        .probe = adx_backlight_probe,
+        .remove = __devexit_p(adx_backlight_remove),
+        .suspend = adx_backlight_suspend,
+        .resume = adx_backlight_resume,
+        .driver = {
+                .name = "adx-backlight",
+                .owner = THIS_MODULE,
+        },
+};
+
+static int __init adx_backlight_init(void)
+{
+        return platform_driver_register(&adx_backlight_driver);
+}
+
+static void __exit adx_backlight_exit(void)
+{
+        platform_driver_unregister(&adx_backlight_driver);
+}
+
+module_init(adx_backlight_init);
+module_exit(adx_backlight_exit);
+
+MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>");
+MODULE_DESCRIPTION("Avionic Design Xanthos Backlight Driver");
+MODULE_LICENSE("GPL v2");