Kristoffer Ericson | 13a7b5d | 2009-02-18 11:50:43 +0000 | [diff] [blame] | 1 | /* |
| 2 | * |
| 3 | * Backlight driver for HP Jornada 700 series (710/720/728) |
| 4 | * Copyright (C) 2006-2009 Kristoffer Ericson <kristoffer.ericson@gmail.com> |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU General Public License version |
| 8 | * 2 or any later version as published by the Free Software Foundation. |
| 9 | * |
| 10 | */ |
| 11 | |
| 12 | #include <linux/backlight.h> |
| 13 | #include <linux/device.h> |
| 14 | #include <linux/fb.h> |
| 15 | #include <linux/kernel.h> |
| 16 | #include <linux/module.h> |
| 17 | #include <linux/platform_device.h> |
| 18 | |
| 19 | #include <mach/jornada720.h> |
| 20 | #include <mach/hardware.h> |
| 21 | |
| 22 | #include <video/s1d13xxxfb.h> |
| 23 | |
| 24 | #define BL_MAX_BRIGHT 255 |
| 25 | #define BL_DEF_BRIGHT 25 |
| 26 | |
| 27 | static int jornada_bl_get_brightness(struct backlight_device *bd) |
| 28 | { |
| 29 | int ret; |
| 30 | |
| 31 | /* check if backlight is on */ |
| 32 | if (!(PPSR & PPC_LDD1)) |
| 33 | return 0; |
| 34 | |
| 35 | jornada_ssp_start(); |
| 36 | |
| 37 | /* cmd should return txdummy */ |
| 38 | ret = jornada_ssp_byte(GETBRIGHTNESS); |
| 39 | |
| 40 | if (jornada_ssp_byte(GETBRIGHTNESS) != TXDUMMY) { |
| 41 | printk(KERN_ERR "bl : get brightness timeout\n"); |
| 42 | jornada_ssp_end(); |
| 43 | return -ETIMEDOUT; |
| 44 | } else /* exchange txdummy for value */ |
| 45 | ret = jornada_ssp_byte(TXDUMMY); |
| 46 | |
| 47 | jornada_ssp_end(); |
| 48 | |
| 49 | return (BL_MAX_BRIGHT - ret); |
| 50 | } |
| 51 | |
| 52 | static int jornada_bl_update_status(struct backlight_device *bd) |
| 53 | { |
| 54 | int ret = 0; |
| 55 | |
| 56 | jornada_ssp_start(); |
| 57 | |
| 58 | /* If backlight is off then really turn it off */ |
| 59 | if ((bd->props.power != FB_BLANK_UNBLANK) || (bd->props.fb_blank != FB_BLANK_UNBLANK)) { |
| 60 | ret = jornada_ssp_byte(BRIGHTNESSOFF); |
| 61 | if (ret != TXDUMMY) { |
| 62 | printk(KERN_INFO "bl : brightness off timeout\n"); |
| 63 | /* turn off backlight */ |
| 64 | PPSR &= ~PPC_LDD1; |
| 65 | PPDR |= PPC_LDD1; |
| 66 | ret = -ETIMEDOUT; |
| 67 | } |
| 68 | } else /* turn on backlight */ |
| 69 | PPSR |= PPC_LDD1; |
| 70 | |
| 71 | /* send command to our mcu */ |
| 72 | if (jornada_ssp_byte(SETBRIGHTNESS) != TXDUMMY) { |
| 73 | printk(KERN_INFO "bl : failed to set brightness\n"); |
| 74 | ret = -ETIMEDOUT; |
Kristoffer Ericson | b317c833 | 2009-07-29 15:04:03 -0700 | [diff] [blame^] | 75 | goto out; |
Kristoffer Ericson | 13a7b5d | 2009-02-18 11:50:43 +0000 | [diff] [blame] | 76 | } |
| 77 | |
| 78 | /* at this point we expect that the mcu has accepted |
| 79 | our command and is waiting for our new value |
| 80 | please note that maximum brightness is 255, |
| 81 | but due to physical layout it is equal to 0, so we simply |
| 82 | invert the value (MAX VALUE - NEW VALUE). */ |
| 83 | if (jornada_ssp_byte(BL_MAX_BRIGHT - bd->props.brightness) != TXDUMMY) { |
| 84 | printk(KERN_ERR "bl : set brightness failed\n"); |
| 85 | ret = -ETIMEDOUT; |
| 86 | } |
| 87 | |
| 88 | /* If infact we get an TXDUMMY as output we are happy and dont |
| 89 | make any further comments about it */ |
| 90 | out: |
| 91 | jornada_ssp_end(); |
| 92 | |
| 93 | return ret; |
| 94 | } |
| 95 | |
| 96 | static struct backlight_ops jornada_bl_ops = { |
| 97 | .get_brightness = jornada_bl_get_brightness, |
| 98 | .update_status = jornada_bl_update_status, |
| 99 | .options = BL_CORE_SUSPENDRESUME, |
| 100 | }; |
| 101 | |
| 102 | static int jornada_bl_probe(struct platform_device *pdev) |
| 103 | { |
| 104 | int ret; |
| 105 | struct backlight_device *bd; |
| 106 | |
| 107 | bd = backlight_device_register(S1D_DEVICENAME, &pdev->dev, NULL, &jornada_bl_ops); |
| 108 | |
| 109 | if (IS_ERR(bd)) { |
| 110 | ret = PTR_ERR(bd); |
| 111 | printk(KERN_ERR "bl : failed to register device, err=%x\n", ret); |
| 112 | return ret; |
| 113 | } |
| 114 | |
| 115 | bd->props.power = FB_BLANK_UNBLANK; |
| 116 | bd->props.brightness = BL_DEF_BRIGHT; |
| 117 | /* note. make sure max brightness is set otherwise |
| 118 | you will get seemingly non-related errors when |
| 119 | trying to change brightness */ |
| 120 | bd->props.max_brightness = BL_MAX_BRIGHT; |
| 121 | jornada_bl_update_status(bd); |
| 122 | |
| 123 | platform_set_drvdata(pdev, bd); |
| 124 | printk(KERN_INFO "HP Jornada 700 series backlight driver\n"); |
| 125 | |
| 126 | return 0; |
| 127 | } |
| 128 | |
| 129 | static int jornada_bl_remove(struct platform_device *pdev) |
| 130 | { |
| 131 | struct backlight_device *bd = platform_get_drvdata(pdev); |
| 132 | |
| 133 | backlight_device_unregister(bd); |
| 134 | |
| 135 | return 0; |
| 136 | } |
| 137 | |
| 138 | static struct platform_driver jornada_bl_driver = { |
| 139 | .probe = jornada_bl_probe, |
| 140 | .remove = jornada_bl_remove, |
| 141 | .driver = { |
| 142 | .name = "jornada_bl", |
| 143 | }, |
| 144 | }; |
| 145 | |
| 146 | int __init jornada_bl_init(void) |
| 147 | { |
| 148 | return platform_driver_register(&jornada_bl_driver); |
| 149 | } |
| 150 | |
| 151 | void __exit jornada_bl_exit(void) |
| 152 | { |
| 153 | platform_driver_unregister(&jornada_bl_driver); |
| 154 | } |
| 155 | |
| 156 | MODULE_AUTHOR("Kristoffer Ericson <kristoffer.ericson>"); |
| 157 | MODULE_DESCRIPTION("HP Jornada 710/720/728 Backlight driver"); |
| 158 | MODULE_LICENSE("GPL"); |
| 159 | |
| 160 | module_init(jornada_bl_init); |
| 161 | module_exit(jornada_bl_exit); |