1/* 2 * Backlight driver for OMAP based boards. 3 * 4 * Copyright (c) 2006 Andrzej Zaborowski <balrog@zabor.org> 5 * 6 * This package is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This package is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this package; if not, write to the Free Software 18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 19 */ 20 21#include <linux/module.h> 22#include <linux/kernel.h> 23#include <linux/init.h> 24#include <linux/platform_device.h> 25#include <linux/fb.h> 26#include <linux/backlight.h> 27#include <linux/slab.h> 28 29#include <mach/hardware.h> 30#include <plat/board.h> 31#include <plat/mux.h> 32 33#define OMAPBL_MAX_INTENSITY 0xff 34 35struct omap_backlight { 36 int powermode; 37 int current_intensity; 38 39 struct device *dev; 40 struct omap_backlight_config *pdata; 41}; 42 43static void inline omapbl_send_intensity(int intensity) 44{ 45 omap_writeb(intensity, OMAP_PWL_ENABLE); 46} 47 48static void inline omapbl_send_enable(int enable) 49{ 50 omap_writeb(enable, OMAP_PWL_CLK_ENABLE); 51} 52 53static void omapbl_blank(struct omap_backlight *bl, int mode) 54{ 55 if (bl->pdata->set_power) 56 bl->pdata->set_power(bl->dev, mode); 57 58 switch (mode) { 59 case FB_BLANK_NORMAL: 60 case FB_BLANK_VSYNC_SUSPEND: 61 case FB_BLANK_HSYNC_SUSPEND: 62 case FB_BLANK_POWERDOWN: 63 omapbl_send_intensity(0); 64 omapbl_send_enable(0); 65 break; 66 67 case FB_BLANK_UNBLANK: 68 omapbl_send_intensity(bl->current_intensity); 69 omapbl_send_enable(1); 70 break; 71 } 72} 73 74#ifdef CONFIG_PM 75static int omapbl_suspend(struct platform_device *pdev, pm_message_t state) 76{ 77 struct backlight_device *dev = platform_get_drvdata(pdev); 78 struct omap_backlight *bl = dev_get_drvdata(&dev->dev); 79 80 omapbl_blank(bl, FB_BLANK_POWERDOWN); 81 return 0; 82} 83 84static int omapbl_resume(struct platform_device *pdev) 85{ 86 struct backlight_device *dev = platform_get_drvdata(pdev); 87 struct omap_backlight *bl = dev_get_drvdata(&dev->dev); 88 89 omapbl_blank(bl, bl->powermode); 90 return 0; 91} 92#else 93#define omapbl_suspend NULL 94#define omapbl_resume NULL 95#endif 96 97static int omapbl_set_power(struct backlight_device *dev, int state) 98{ 99 struct omap_backlight *bl = dev_get_drvdata(&dev->dev); 100 101 omapbl_blank(bl, state); 102 bl->powermode = state; 103 104 return 0; 105} 106 107static int omapbl_update_status(struct backlight_device *dev) 108{ 109 struct omap_backlight *bl = dev_get_drvdata(&dev->dev); 110 111 if (bl->current_intensity != dev->props.brightness) { 112 if (bl->powermode == FB_BLANK_UNBLANK) 113 omapbl_send_intensity(dev->props.brightness); 114 bl->current_intensity = dev->props.brightness; 115 } 116 117 if (dev->props.fb_blank != bl->powermode) 118 omapbl_set_power(dev, dev->props.fb_blank); 119 120 return 0; 121} 122 123static int omapbl_get_intensity(struct backlight_device *dev) 124{ 125 struct omap_backlight *bl = dev_get_drvdata(&dev->dev); 126 return bl->current_intensity; 127} 128 129static const struct backlight_ops omapbl_ops = { 130 .get_brightness = omapbl_get_intensity, 131 .update_status = omapbl_update_status, 132}; 133 134static int omapbl_probe(struct platform_device *pdev) 135{ 136 struct backlight_properties props; 137 struct backlight_device *dev; 138 struct omap_backlight *bl; 139 struct omap_backlight_config *pdata = pdev->dev.platform_data; 140 141 if (!pdata) 142 return -ENXIO; 143 144 bl = kzalloc(sizeof(struct omap_backlight), GFP_KERNEL); 145 if (unlikely(!bl)) 146 return -ENOMEM; 147 148 memset(&props, 0, sizeof(struct backlight_properties)); 149 props.max_brightness = OMAPBL_MAX_INTENSITY; 150 dev = backlight_device_register("omap-bl", &pdev->dev, bl, &omapbl_ops, 151 &props); 152 if (IS_ERR(dev)) { 153 kfree(bl); 154 return PTR_ERR(dev); 155 } 156 157 bl->powermode = FB_BLANK_POWERDOWN; 158 bl->current_intensity = 0; 159 160 bl->pdata = pdata; 161 bl->dev = &pdev->dev; 162 163 platform_set_drvdata(pdev, dev); 164 165 omap_cfg_reg(PWL); /* Conflicts with UART3 */ 166 167 dev->props.fb_blank = FB_BLANK_UNBLANK; 168 dev->props.brightness = pdata->default_intensity; 169 omapbl_update_status(dev); 170 171 printk(KERN_INFO "OMAP LCD backlight initialised\n"); 172 173 return 0; 174} 175 176static int omapbl_remove(struct platform_device *pdev) 177{ 178 struct backlight_device *dev = platform_get_drvdata(pdev); 179 struct omap_backlight *bl = dev_get_drvdata(&dev->dev); 180 181 backlight_device_unregister(dev); 182 kfree(bl); 183 184 return 0; 185} 186 187static struct platform_driver omapbl_driver = { 188 .probe = omapbl_probe, 189 .remove = omapbl_remove, 190 .suspend = omapbl_suspend, 191 .resume = omapbl_resume, 192 .driver = { 193 .name = "omap-bl", 194 }, 195}; 196 197static int __init omapbl_init(void) 198{ 199 return platform_driver_register(&omapbl_driver); 200} 201 202static void __exit omapbl_exit(void) 203{ 204 platform_driver_unregister(&omapbl_driver); 205} 206 207module_init(omapbl_init); 208module_exit(omapbl_exit); 209 210MODULE_AUTHOR("Andrzej Zaborowski <balrog@zabor.org>"); 211MODULE_DESCRIPTION("OMAP LCD Backlight driver"); 212MODULE_LICENSE("GPL"); 213