backlight: Adds HP Jornada 700 series backlight driver

Signed-off-by: Kristoffer Ericson <kristoffer.ericson@gmail.com>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>

3 files changed, 171 insertions, 0 deletions

diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
index 1064f69e1e87..f9d19be05540 100644
--- a/drivers/video/backlight/Kconfig
+++ b/drivers/video/backlight/Kconfig
@@ -166,6 +166,15 @@ config BACKLIGHT_HP680
           If you have a HP Jornada 680, say y to enable the
           backlight driver.
 
+config BACKLIGHT_HP700
+        tristate "HP Jornada 700 series Backlight Driver"
+        depends on BACKLIGHT_CLASS_DEVICE
+        depends on SA1100_JORNADA720_SSP && !PREEMPT
+        default y
+        help
+          If you have an HP Jornada 700 series,
+          say Y to include backlight control driver.
+
 config BACKLIGHT_PROGEAR
         tristate "Frontpath ProGear Backlight Driver"
         depends on BACKLIGHT_CLASS_DEVICE && PCI && X86
diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
index c508075157b2..4eb178c1d684 100644
--- a/drivers/video/backlight/Makefile
+++ b/drivers/video/backlight/Makefile
@@ -13,6 +13,7 @@ obj-$(CONFIG_LCD_TOSA)		   += tosa_lcd.o
 obj-$(CONFIG_BACKLIGHT_CLASS_DEVICE) += backlight.o
 obj-$(CONFIG_BACKLIGHT_ATMEL_PWM)    += atmel-pwm-bl.o
 obj-$(CONFIG_BACKLIGHT_GENERIC) += generic_bl.o
+obj-$(CONFIG_BACKLIGHT_HP700)   += jornada720_bl.o
 obj-$(CONFIG_BACKLIGHT_HP680)   += hp680_bl.o
 obj-$(CONFIG_BACKLIGHT_LOCOMO)  += locomolcd.o
 obj-$(CONFIG_BACKLIGHT_OMAP1)   += omap1_bl.o
diff --git a/drivers/video/backlight/jornada720_bl.c b/drivers/video/backlight/jornada720_bl.c
new file mode 100644
index 000000000000..c3ebb6b41ce1
--- /dev/null
+++ b/drivers/video/backlight/jornada720_bl.c
@@ -0,0 +1,161 @@
+/*
+ *
+ * Backlight driver for HP Jornada 700 series (710/720/728)
+ * Copyright (C) 2006-2009 Kristoffer Ericson <kristoffer.ericson@gmail.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 or any later version as published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/backlight.h>
+#include <linux/device.h>
+#include <linux/fb.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#include <mach/jornada720.h>
+#include <mach/hardware.h>
+
+#include <video/s1d13xxxfb.h>
+
+#define BL_MAX_BRIGHT   255
+#define BL_DEF_BRIGHT   25
+
+static int jornada_bl_get_brightness(struct backlight_device *bd)
+{
+        int ret;
+
+        /* check if backlight is on */
+        if (!(PPSR & PPC_LDD1))
+                return 0;
+
+        jornada_ssp_start();
+
+        /* cmd should return txdummy */
+        ret = jornada_ssp_byte(GETBRIGHTNESS);
+
+        if (jornada_ssp_byte(GETBRIGHTNESS) != TXDUMMY) {
+                printk(KERN_ERR "bl : get brightness timeout\n");
+                jornada_ssp_end();
+                return -ETIMEDOUT;
+        } else /* exchange txdummy for value */
+                ret = jornada_ssp_byte(TXDUMMY);
+
+        jornada_ssp_end();
+
+        return (BL_MAX_BRIGHT - ret);
+}
+
+static int jornada_bl_update_status(struct backlight_device *bd)
+{
+        int ret = 0;
+
+        jornada_ssp_start();
+
+        /* If backlight is off then really turn it off */
+        if ((bd->props.power != FB_BLANK_UNBLANK) || (bd->props.fb_blank != FB_BLANK_UNBLANK)) {
+                ret = jornada_ssp_byte(BRIGHTNESSOFF);
+                if (ret != TXDUMMY) {
+                        printk(KERN_INFO "bl : brightness off timeout\n");
+                        /* turn off backlight */
+                        PPSR &= ~PPC_LDD1;
+                        PPDR |= PPC_LDD1;
+                        ret = -ETIMEDOUT;
+                }
+        } else  /* turn on backlight */
+                PPSR |= PPC_LDD1;
+
+                /* send command to our mcu */
+                if (jornada_ssp_byte(SETBRIGHTNESS) != TXDUMMY) {
+                        printk(KERN_INFO "bl : failed to set brightness\n");
+                        ret = -ETIMEDOUT;
+                        goto out
+                }
+
+                /* at this point we expect that the mcu has accepted
+                   our command and is waiting for our new value
+                   please note that maximum brightness is 255,
+                   but due to physical layout it is equal to 0, so we simply
+                   invert the value (MAX VALUE - NEW VALUE). */
+                if (jornada_ssp_byte(BL_MAX_BRIGHT - bd->props.brightness) != TXDUMMY) {
+                        printk(KERN_ERR "bl : set brightness failed\n");
+                        ret = -ETIMEDOUT;
+                }
+
+                /* If infact we get an TXDUMMY as output we are happy and dont
+                   make any further comments about it */
+out:
+        jornada_ssp_end();
+
+        return ret;
+}
+
+static struct backlight_ops jornada_bl_ops = {
+        .get_brightness = jornada_bl_get_brightness,
+        .update_status = jornada_bl_update_status,
+        .options = BL_CORE_SUSPENDRESUME,
+};
+
+static int jornada_bl_probe(struct platform_device *pdev)
+{
+        int ret;
+        struct backlight_device *bd;
+
+        bd = backlight_device_register(S1D_DEVICENAME, &pdev->dev, NULL, &jornada_bl_ops);
+
+        if (IS_ERR(bd)) {
+                ret = PTR_ERR(bd);
+                printk(KERN_ERR "bl : failed to register device, err=%x\n", ret);
+                return ret;
+        }
+
+        bd->props.power = FB_BLANK_UNBLANK;
+        bd->props.brightness = BL_DEF_BRIGHT;
+        /* note. make sure max brightness is set otherwise
+           you will get seemingly non-related errors when
+           trying to change brightness */
+        bd->props.max_brightness = BL_MAX_BRIGHT;
+        jornada_bl_update_status(bd);
+
+        platform_set_drvdata(pdev, bd);
+        printk(KERN_INFO "HP Jornada 700 series backlight driver\n");
+
+        return 0;
+}
+
+static int jornada_bl_remove(struct platform_device *pdev)
+{
+        struct backlight_device *bd = platform_get_drvdata(pdev);
+
+        backlight_device_unregister(bd);
+
+        return 0;
+}
+
+static struct platform_driver jornada_bl_driver = {
+        .probe          = jornada_bl_probe,
+        .remove         = jornada_bl_remove,
+        .driver = {
+                .name   = "jornada_bl",
+        },
+};
+
+int __init jornada_bl_init(void)
+{
+        return platform_driver_register(&jornada_bl_driver);
+}
+
+void __exit jornada_bl_exit(void)
+{
+        platform_driver_unregister(&jornada_bl_driver);
+}
+
+MODULE_AUTHOR("Kristoffer Ericson <kristoffer.ericson>");
+MODULE_DESCRIPTION("HP Jornada 710/720/728 Backlight driver");
+MODULE_LICENSE("GPL");
+
+module_init(jornada_bl_init);
+module_exit(jornada_bl_exit);