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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Backlight driver for OMAP based boards.4 *5 * Copyright (c) 2006 Andrzej Zaborowski <balrog@zabor.org>6 */7 8#include <linux/module.h>9#include <linux/kernel.h>10#include <linux/init.h>11#include <linux/platform_device.h>12#include <linux/backlight.h>13#include <linux/slab.h>14#include <linux/platform_data/omap1_bl.h>15 16#include <linux/soc/ti/omap1-io.h>17#include <linux/soc/ti/omap1-mux.h>18 19#define OMAPBL_MAX_INTENSITY 0xff20 21struct omap_backlight {22 bool enabled;23 int current_intensity;24 25 struct device *dev;26 struct omap_backlight_config *pdata;27};28 29static inline void omapbl_send_intensity(int intensity)30{31 omap_writeb(intensity, OMAP_PWL_ENABLE);32}33 34static inline void omapbl_send_enable(int enable)35{36 omap_writeb(enable, OMAP_PWL_CLK_ENABLE);37}38 39static void omapbl_enable(struct omap_backlight *bl, bool enable)40{41 if (enable) {42 omapbl_send_intensity(bl->current_intensity);43 omapbl_send_enable(1);44 } else {45 omapbl_send_intensity(0);46 omapbl_send_enable(0);47 }48}49 50#ifdef CONFIG_PM_SLEEP51static int omapbl_suspend(struct device *dev)52{53 struct backlight_device *bl_dev = dev_get_drvdata(dev);54 struct omap_backlight *bl = bl_get_data(bl_dev);55 56 omapbl_enable(bl, false);57 return 0;58}59 60static int omapbl_resume(struct device *dev)61{62 struct backlight_device *bl_dev = dev_get_drvdata(dev);63 struct omap_backlight *bl = bl_get_data(bl_dev);64 65 omapbl_enable(bl, bl->enabled);66 return 0;67}68#endif69 70static void omapbl_set_enabled(struct backlight_device *dev, bool enable)71{72 struct omap_backlight *bl = bl_get_data(dev);73 74 omapbl_enable(bl, enable);75 bl->enabled = enable;76}77 78static int omapbl_update_status(struct backlight_device *dev)79{80 struct omap_backlight *bl = bl_get_data(dev);81 bool enable;82 83 if (bl->current_intensity != dev->props.brightness) {84 if (bl->enabled)85 omapbl_send_intensity(dev->props.brightness);86 bl->current_intensity = dev->props.brightness;87 }88 89 enable = !backlight_is_blank(dev);90 91 if (enable != bl->enabled)92 omapbl_set_enabled(dev, enable);93 94 return 0;95}96 97static int omapbl_get_intensity(struct backlight_device *dev)98{99 struct omap_backlight *bl = bl_get_data(dev);100 101 return bl->current_intensity;102}103 104static const struct backlight_ops omapbl_ops = {105 .get_brightness = omapbl_get_intensity,106 .update_status = omapbl_update_status,107};108 109static int omapbl_probe(struct platform_device *pdev)110{111 struct backlight_properties props;112 struct backlight_device *dev;113 struct omap_backlight *bl;114 struct omap_backlight_config *pdata = dev_get_platdata(&pdev->dev);115 116 if (!pdata)117 return -ENXIO;118 119 bl = devm_kzalloc(&pdev->dev, sizeof(struct omap_backlight),120 GFP_KERNEL);121 if (unlikely(!bl))122 return -ENOMEM;123 124 memset(&props, 0, sizeof(struct backlight_properties));125 props.type = BACKLIGHT_RAW;126 props.max_brightness = OMAPBL_MAX_INTENSITY;127 dev = devm_backlight_device_register(&pdev->dev, "omap-bl", &pdev->dev,128 bl, &omapbl_ops, &props);129 if (IS_ERR(dev))130 return PTR_ERR(dev);131 132 bl->enabled = false;133 bl->current_intensity = 0;134 135 bl->pdata = pdata;136 bl->dev = &pdev->dev;137 138 platform_set_drvdata(pdev, dev);139 140 omap_cfg_reg(PWL); /* Conflicts with UART3 */141 142 dev->props.brightness = pdata->default_intensity;143 omapbl_update_status(dev);144 145 dev_info(&pdev->dev, "OMAP LCD backlight initialised\n");146 147 return 0;148}149 150static SIMPLE_DEV_PM_OPS(omapbl_pm_ops, omapbl_suspend, omapbl_resume);151 152static struct platform_driver omapbl_driver = {153 .probe = omapbl_probe,154 .driver = {155 .name = "omap-bl",156 .pm = &omapbl_pm_ops,157 },158};159 160module_platform_driver(omapbl_driver);161 162MODULE_AUTHOR("Andrzej Zaborowski <balrog@zabor.org>");163MODULE_DESCRIPTION("OMAP LCD Backlight driver");164MODULE_LICENSE("GPL");165