diff options
Diffstat (limited to 'drivers/video/backlight/jornada720_bl.c')
| -rw-r--r-- | drivers/video/backlight/jornada720_bl.c | 161 |
1 files changed, 161 insertions, 0 deletions
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); |