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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 | // SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de> * PCF50633 backlight device driver */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/slab.h> #include <linux/platform_device.h> #include <linux/backlight.h> #include <linux/fb.h> #include <linux/mfd/pcf50633/core.h> #include <linux/mfd/pcf50633/backlight.h> struct pcf50633_bl { struct pcf50633 *pcf; struct backlight_device *bl; unsigned int brightness; unsigned int brightness_limit; }; /* * pcf50633_bl_set_brightness_limit * * Update the brightness limit for the pc50633 backlight. The actual brightness * will not go above the limit. This is useful to limit power drain for example * on low battery. * * @dev: Pointer to a pcf50633 device * @limit: The brightness limit. Valid values are 0-63 */ int pcf50633_bl_set_brightness_limit(struct pcf50633 *pcf, unsigned int limit) { struct pcf50633_bl *pcf_bl = platform_get_drvdata(pcf->bl_pdev); if (!pcf_bl) return -ENODEV; pcf_bl->brightness_limit = limit & 0x3f; backlight_update_status(pcf_bl->bl); return 0; } static int pcf50633_bl_update_status(struct backlight_device *bl) { struct pcf50633_bl *pcf_bl = bl_get_data(bl); unsigned int new_brightness; if (bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK) || bl->props.power != FB_BLANK_UNBLANK) new_brightness = 0; else if (bl->props.brightness < pcf_bl->brightness_limit) new_brightness = bl->props.brightness; else new_brightness = pcf_bl->brightness_limit; if (pcf_bl->brightness == new_brightness) return 0; if (new_brightness) { pcf50633_reg_write(pcf_bl->pcf, PCF50633_REG_LEDOUT, new_brightness); if (!pcf_bl->brightness) pcf50633_reg_write(pcf_bl->pcf, PCF50633_REG_LEDENA, 1); } else { pcf50633_reg_write(pcf_bl->pcf, PCF50633_REG_LEDENA, 0); } pcf_bl->brightness = new_brightness; return 0; } static int pcf50633_bl_get_brightness(struct backlight_device *bl) { struct pcf50633_bl *pcf_bl = bl_get_data(bl); return pcf_bl->brightness; } static const struct backlight_ops pcf50633_bl_ops = { .get_brightness = pcf50633_bl_get_brightness, .update_status = pcf50633_bl_update_status, .options = BL_CORE_SUSPENDRESUME, }; static int pcf50633_bl_probe(struct platform_device *pdev) { struct pcf50633_bl *pcf_bl; struct device *parent = pdev->dev.parent; struct pcf50633_platform_data *pcf50633_data = dev_get_platdata(parent); struct pcf50633_bl_platform_data *pdata = pcf50633_data->backlight_data; struct backlight_properties bl_props; pcf_bl = devm_kzalloc(&pdev->dev, sizeof(*pcf_bl), GFP_KERNEL); if (!pcf_bl) return -ENOMEM; memset(&bl_props, 0, sizeof(bl_props)); bl_props.type = BACKLIGHT_RAW; bl_props.max_brightness = 0x3f; bl_props.power = FB_BLANK_UNBLANK; if (pdata) { bl_props.brightness = pdata->default_brightness; pcf_bl->brightness_limit = pdata->default_brightness_limit; } else { bl_props.brightness = 0x3f; pcf_bl->brightness_limit = 0x3f; } pcf_bl->pcf = dev_to_pcf50633(pdev->dev.parent); pcf_bl->bl = devm_backlight_device_register(&pdev->dev, pdev->name, &pdev->dev, pcf_bl, &pcf50633_bl_ops, &bl_props); if (IS_ERR(pcf_bl->bl)) return PTR_ERR(pcf_bl->bl); platform_set_drvdata(pdev, pcf_bl); pcf50633_reg_write(pcf_bl->pcf, PCF50633_REG_LEDDIM, pdata->ramp_time); /* * Should be different from bl_props.brightness, so we do not exit * update_status early the first time it's called */ pcf_bl->brightness = pcf_bl->bl->props.brightness + 1; backlight_update_status(pcf_bl->bl); return 0; } static struct platform_driver pcf50633_bl_driver = { .probe = pcf50633_bl_probe, .driver = { .name = "pcf50633-backlight", }, }; module_platform_driver(pcf50633_bl_driver); MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); MODULE_DESCRIPTION("PCF50633 backlight driver"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:pcf50633-backlight"); |