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 28 #include <asm/arch/hardware.h> 29 #include <asm/arch/board.h> 30 #include <asm/arch/mux.h> 31 32 #define OMAPBL_MAX_INTENSITY 0xff 33 34 struct omap_backlight { 35 int powermode; 36 int current_intensity; 37 38 struct device *dev; 39 struct omap_backlight_config *pdata; 40 }; 41 42 static void inline omapbl_send_intensity(int intensity) 43 { 44 omap_writeb(intensity, OMAP_PWL_ENABLE); 45 } 46 47 static void inline omapbl_send_enable(int enable) 48 { 49 omap_writeb(enable, OMAP_PWL_CLK_ENABLE); 50 } 51 52 static void omapbl_blank(struct omap_backlight *bl, int mode) 53 { 54 if (bl->pdata->set_power) 55 bl->pdata->set_power(bl->dev, mode); 56 57 switch (mode) { 58 case FB_BLANK_NORMAL: 59 case FB_BLANK_VSYNC_SUSPEND: 60 case FB_BLANK_HSYNC_SUSPEND: 61 case FB_BLANK_POWERDOWN: 62 omapbl_send_intensity(0); 63 omapbl_send_enable(0); 64 break; 65 66 case FB_BLANK_UNBLANK: 67 omapbl_send_intensity(bl->current_intensity); 68 omapbl_send_enable(1); 69 break; 70 } 71 } 72 73 #ifdef CONFIG_PM 74 static int omapbl_suspend(struct platform_device *pdev, pm_message_t state) 75 { 76 struct backlight_device *dev = platform_get_drvdata(pdev); 77 struct omap_backlight *bl = dev_get_drvdata(&dev->dev); 78 79 omapbl_blank(bl, FB_BLANK_POWERDOWN); 80 return 0; 81 } 82 83 static int omapbl_resume(struct platform_device *pdev) 84 { 85 struct backlight_device *dev = platform_get_drvdata(pdev); 86 struct omap_backlight *bl = dev_get_drvdata(&dev->dev); 87 88 omapbl_blank(bl, bl->powermode); 89 return 0; 90 } 91 #else 92 #define omapbl_suspend NULL 93 #define omapbl_resume NULL 94 #endif 95 96 static int omapbl_set_power(struct backlight_device *dev, int state) 97 { 98 struct omap_backlight *bl = dev_get_drvdata(&dev->dev); 99 100 omapbl_blank(bl, state); 101 bl->powermode = state; 102 103 return 0; 104 } 105 106 static int omapbl_update_status(struct backlight_device *dev) 107 { 108 struct omap_backlight *bl = dev_get_drvdata(&dev->dev); 109 110 if (bl->current_intensity != dev->props.brightness) { 111 if (bl->powermode == FB_BLANK_UNBLANK) 112 omapbl_send_intensity(dev->props.brightness); 113 bl->current_intensity = dev->props.brightness; 114 } 115 116 if (dev->props.fb_blank != bl->powermode) 117 omapbl_set_power(dev, dev->props.fb_blank); 118 119 return 0; 120 } 121 122 static int omapbl_get_intensity(struct backlight_device *dev) 123 { 124 struct omap_backlight *bl = dev_get_drvdata(&dev->dev); 125 return bl->current_intensity; 126 } 127 128 static struct backlight_ops omapbl_ops = { 129 .get_brightness = omapbl_get_intensity, 130 .update_status = omapbl_update_status, 131 }; 132 133 static int omapbl_probe(struct platform_device *pdev) 134 { 135 struct backlight_device *dev; 136 struct omap_backlight *bl; 137 struct omap_backlight_config *pdata = pdev->dev.platform_data; 138 139 if (!pdata) 140 return -ENXIO; 141 142 omapbl_ops.check_fb = pdata->check_fb; 143 144 bl = kzalloc(sizeof(struct omap_backlight), GFP_KERNEL); 145 if (unlikely(!bl)) 146 return -ENOMEM; 147 148 dev = backlight_device_register("omap-bl", &pdev->dev, bl, &omapbl_ops); 149 if (IS_ERR(dev)) { 150 kfree(bl); 151 return PTR_ERR(dev); 152 } 153 154 bl->powermode = FB_BLANK_POWERDOWN; 155 bl->current_intensity = 0; 156 157 bl->pdata = pdata; 158 bl->dev = &pdev->dev; 159 160 platform_set_drvdata(pdev, dev); 161 162 omap_cfg_reg(PWL); /* Conflicts with UART3 */ 163 164 dev->props.fb_blank = FB_BLANK_UNBLANK; 165 dev->props.max_brightness = OMAPBL_MAX_INTENSITY; 166 dev->props.brightness = pdata->default_intensity; 167 omapbl_update_status(dev); 168 169 printk(KERN_INFO "OMAP LCD backlight initialised\n"); 170 171 return 0; 172 } 173 174 static int omapbl_remove(struct platform_device *pdev) 175 { 176 struct backlight_device *dev = platform_get_drvdata(pdev); 177 struct omap_backlight *bl = dev_get_drvdata(&dev->dev); 178 179 backlight_device_unregister(dev); 180 kfree(bl); 181 182 return 0; 183 } 184 185 static struct platform_driver omapbl_driver = { 186 .probe = omapbl_probe, 187 .remove = omapbl_remove, 188 .suspend = omapbl_suspend, 189 .resume = omapbl_resume, 190 .driver = { 191 .name = "omap-bl", 192 }, 193 }; 194 195 static int __init omapbl_init(void) 196 { 197 return platform_driver_register(&omapbl_driver); 198 } 199 200 static void __exit omapbl_exit(void) 201 { 202 platform_driver_unregister(&omapbl_driver); 203 } 204 205 module_init(omapbl_init); 206 module_exit(omapbl_exit); 207 208 MODULE_AUTHOR("Andrzej Zaborowski <balrog@zabor.org>"); 209 MODULE_DESCRIPTION("OMAP LCD Backlight driver"); 210 MODULE_LICENSE("GPL"); 211