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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 22 23 #include <linux/module.h> 24 #include <linux/kernel.h> 25 #include <linux/init.h> 26 #include <linux/platform_device.h> 27 #include <linux/fb.h> 28 #include <linux/backlight.h> 29 #include <linux/slab.h> 30 #include <linux/platform_data/omap1_bl.h> 31 32 #include <mach/hardware.h> 33 #include <mach/mux.h> 34 35 #define OMAPBL_MAX_INTENSITY 0xff 36 37 struct omap_backlight { 38 int powermode; 39 int current_intensity; 40 41 struct device *dev; 42 struct omap_backlight_config *pdata; 43 }; 44 45 static inline void omapbl_send_intensity(int intensity) 46 { 47 omap_writeb(intensity, OMAP_PWL_ENABLE); 48 } 49 50 static inline void omapbl_send_enable(int enable) 51 { 52 omap_writeb(enable, OMAP_PWL_CLK_ENABLE); 53 } 54 55 static void omapbl_blank(struct omap_backlight *bl, int mode) 56 { 57 if (bl->pdata->set_power) 58 bl->pdata->set_power(bl->dev, mode); 59 60 switch (mode) { 61 case FB_BLANK_NORMAL: 62 case FB_BLANK_VSYNC_SUSPEND: 63 case FB_BLANK_HSYNC_SUSPEND: 64 case FB_BLANK_POWERDOWN: 65 omapbl_send_intensity(0); 66 omapbl_send_enable(0); 67 break; 68 69 case FB_BLANK_UNBLANK: 70 omapbl_send_intensity(bl->current_intensity); 71 omapbl_send_enable(1); 72 break; 73 } 74 } 75 76 #ifdef CONFIG_PM 77 static int omapbl_suspend(struct platform_device *pdev, pm_message_t state) 78 { 79 struct backlight_device *dev = platform_get_drvdata(pdev); 80 struct omap_backlight *bl = dev_get_drvdata(&dev->dev); 81 82 omapbl_blank(bl, FB_BLANK_POWERDOWN); 83 return 0; 84 } 85 86 static int omapbl_resume(struct platform_device *pdev) 87 { 88 struct backlight_device *dev = platform_get_drvdata(pdev); 89 struct omap_backlight *bl = dev_get_drvdata(&dev->dev); 90 91 omapbl_blank(bl, bl->powermode); 92 return 0; 93 } 94 #else 95 #define omapbl_suspend NULL 96 #define omapbl_resume NULL 97 #endif 98 99 static int omapbl_set_power(struct backlight_device *dev, int state) 100 { 101 struct omap_backlight *bl = dev_get_drvdata(&dev->dev); 102 103 omapbl_blank(bl, state); 104 bl->powermode = state; 105 106 return 0; 107 } 108 109 static int omapbl_update_status(struct backlight_device *dev) 110 { 111 struct omap_backlight *bl = dev_get_drvdata(&dev->dev); 112 113 if (bl->current_intensity != dev->props.brightness) { 114 if (bl->powermode == FB_BLANK_UNBLANK) 115 omapbl_send_intensity(dev->props.brightness); 116 bl->current_intensity = dev->props.brightness; 117 } 118 119 if (dev->props.fb_blank != bl->powermode) 120 omapbl_set_power(dev, dev->props.fb_blank); 121 122 return 0; 123 } 124 125 static int omapbl_get_intensity(struct backlight_device *dev) 126 { 127 struct omap_backlight *bl = dev_get_drvdata(&dev->dev); 128 return bl->current_intensity; 129 } 130 131 static const struct backlight_ops omapbl_ops = { 132 .get_brightness = omapbl_get_intensity, 133 .update_status = omapbl_update_status, 134 }; 135 136 static int omapbl_probe(struct platform_device *pdev) 137 { 138 struct backlight_properties props; 139 struct backlight_device *dev; 140 struct omap_backlight *bl; 141 struct omap_backlight_config *pdata = pdev->dev.platform_data; 142 143 if (!pdata) 144 return -ENXIO; 145 146 bl = devm_kzalloc(&pdev->dev, sizeof(struct omap_backlight), 147 GFP_KERNEL); 148 if (unlikely(!bl)) 149 return -ENOMEM; 150 151 memset(&props, 0, sizeof(struct backlight_properties)); 152 props.type = BACKLIGHT_RAW; 153 props.max_brightness = OMAPBL_MAX_INTENSITY; 154 dev = backlight_device_register("omap-bl", &pdev->dev, bl, &omapbl_ops, 155 &props); 156 if (IS_ERR(dev)) 157 return PTR_ERR(dev); 158 159 bl->powermode = FB_BLANK_POWERDOWN; 160 bl->current_intensity = 0; 161 162 bl->pdata = pdata; 163 bl->dev = &pdev->dev; 164 165 platform_set_drvdata(pdev, dev); 166 167 omap_cfg_reg(PWL); /* Conflicts with UART3 */ 168 169 dev->props.fb_blank = FB_BLANK_UNBLANK; 170 dev->props.brightness = pdata->default_intensity; 171 omapbl_update_status(dev); 172 173 pr_info("OMAP LCD backlight initialised\n"); 174 175 return 0; 176 } 177 178 static int omapbl_remove(struct platform_device *pdev) 179 { 180 struct backlight_device *dev = platform_get_drvdata(pdev); 181 182 backlight_device_unregister(dev); 183 184 return 0; 185 } 186 187 static 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 }; 196 197 module_platform_driver(omapbl_driver); 198 199 MODULE_AUTHOR("Andrzej Zaborowski <balrog@zabor.org>"); 200 MODULE_DESCRIPTION("OMAP LCD Backlight driver"); 201 MODULE_LICENSE("GPL"); 202