Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 1 | /* |
| 2 | * Backlight driver for Maxim MAX8925 |
| 3 | * |
| 4 | * Copyright (C) 2009 Marvell International Ltd. |
| 5 | * Haojian Zhuang <haojian.zhuang@marvell.com> |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License version 2 as |
| 9 | * published by the Free Software Foundation. |
| 10 | */ |
| 11 | |
| 12 | #include <linux/init.h> |
| 13 | #include <linux/kernel.h> |
| 14 | #include <linux/platform_device.h> |
| 15 | #include <linux/fb.h> |
| 16 | #include <linux/i2c.h> |
| 17 | #include <linux/backlight.h> |
| 18 | #include <linux/mfd/max8925.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 19 | #include <linux/slab.h> |
Paul Gortmaker | 355b200 | 2011-07-03 16:17:28 -0400 | [diff] [blame] | 20 | #include <linux/module.h> |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 21 | |
| 22 | #define MAX_BRIGHTNESS (0xff) |
| 23 | #define MIN_BRIGHTNESS (0) |
| 24 | |
| 25 | #define LWX_FREQ(x) (((x - 601) / 100) & 0x7) |
| 26 | |
| 27 | struct max8925_backlight_data { |
| 28 | struct max8925_chip *chip; |
| 29 | |
Haojian Zhuang | 63b501e | 2012-09-17 12:19:04 +0800 | [diff] [blame] | 30 | int current_brightness; |
| 31 | int reg_mode_cntl; |
| 32 | int reg_cntl; |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 33 | }; |
| 34 | |
| 35 | static int max8925_backlight_set(struct backlight_device *bl, int brightness) |
| 36 | { |
| 37 | struct max8925_backlight_data *data = bl_get_data(bl); |
| 38 | struct max8925_chip *chip = data->chip; |
| 39 | unsigned char value; |
| 40 | int ret; |
| 41 | |
| 42 | if (brightness > MAX_BRIGHTNESS) |
| 43 | value = MAX_BRIGHTNESS; |
| 44 | else |
| 45 | value = brightness; |
| 46 | |
Haojian Zhuang | 63b501e | 2012-09-17 12:19:04 +0800 | [diff] [blame] | 47 | ret = max8925_reg_write(chip->i2c, data->reg_cntl, value); |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 48 | if (ret < 0) |
| 49 | goto out; |
| 50 | |
| 51 | if (!data->current_brightness && brightness) |
| 52 | /* enable WLED output */ |
Haojian Zhuang | 63b501e | 2012-09-17 12:19:04 +0800 | [diff] [blame] | 53 | ret = max8925_set_bits(chip->i2c, data->reg_mode_cntl, 1, 1); |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 54 | else if (!brightness) |
| 55 | /* disable WLED output */ |
Haojian Zhuang | 63b501e | 2012-09-17 12:19:04 +0800 | [diff] [blame] | 56 | ret = max8925_set_bits(chip->i2c, data->reg_mode_cntl, 1, 0); |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 57 | if (ret < 0) |
| 58 | goto out; |
| 59 | dev_dbg(chip->dev, "set brightness %d\n", value); |
| 60 | data->current_brightness = value; |
| 61 | return 0; |
| 62 | out: |
| 63 | dev_dbg(chip->dev, "set brightness %d failure with return value:%d\n", |
| 64 | value, ret); |
| 65 | return ret; |
| 66 | } |
| 67 | |
| 68 | static int max8925_backlight_update_status(struct backlight_device *bl) |
| 69 | { |
| 70 | int brightness = bl->props.brightness; |
| 71 | |
| 72 | if (bl->props.power != FB_BLANK_UNBLANK) |
| 73 | brightness = 0; |
| 74 | |
| 75 | if (bl->props.fb_blank != FB_BLANK_UNBLANK) |
| 76 | brightness = 0; |
| 77 | |
| 78 | if (bl->props.state & BL_CORE_SUSPENDED) |
| 79 | brightness = 0; |
| 80 | |
| 81 | return max8925_backlight_set(bl, brightness); |
| 82 | } |
| 83 | |
| 84 | static int max8925_backlight_get_brightness(struct backlight_device *bl) |
| 85 | { |
| 86 | struct max8925_backlight_data *data = bl_get_data(bl); |
| 87 | struct max8925_chip *chip = data->chip; |
| 88 | int ret; |
| 89 | |
Haojian Zhuang | 63b501e | 2012-09-17 12:19:04 +0800 | [diff] [blame] | 90 | ret = max8925_reg_read(chip->i2c, data->reg_cntl); |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 91 | if (ret < 0) |
| 92 | return -EINVAL; |
| 93 | data->current_brightness = ret; |
| 94 | dev_dbg(chip->dev, "get brightness %d\n", data->current_brightness); |
| 95 | return ret; |
| 96 | } |
| 97 | |
Lionel Debroux | acc2472 | 2010-11-16 14:14:02 +0100 | [diff] [blame] | 98 | static const struct backlight_ops max8925_backlight_ops = { |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 99 | .options = BL_CORE_SUSPENDRESUME, |
| 100 | .update_status = max8925_backlight_update_status, |
| 101 | .get_brightness = max8925_backlight_get_brightness, |
| 102 | }; |
| 103 | |
Bill Pemberton | 1b9e450 | 2012-11-19 13:21:46 -0500 | [diff] [blame] | 104 | static int max8925_backlight_probe(struct platform_device *pdev) |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 105 | { |
| 106 | struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent); |
Haojian Zhuang | 63b501e | 2012-09-17 12:19:04 +0800 | [diff] [blame] | 107 | struct max8925_backlight_pdata *pdata = pdev->dev.platform_data; |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 108 | struct max8925_backlight_data *data; |
| 109 | struct backlight_device *bl; |
Matthew Garrett | a19a6ee | 2010-02-17 16:39:44 -0500 | [diff] [blame] | 110 | struct backlight_properties props; |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 111 | struct resource *res; |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 112 | unsigned char value; |
Haojian Zhuang | 63b501e | 2012-09-17 12:19:04 +0800 | [diff] [blame] | 113 | int ret = 0; |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 114 | |
Julia Lawall | ce96922 | 2012-03-23 15:02:00 -0700 | [diff] [blame] | 115 | data = devm_kzalloc(&pdev->dev, sizeof(struct max8925_backlight_data), |
| 116 | GFP_KERNEL); |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 117 | if (data == NULL) |
| 118 | return -ENOMEM; |
Haojian Zhuang | 63b501e | 2012-09-17 12:19:04 +0800 | [diff] [blame] | 119 | |
| 120 | res = platform_get_resource(pdev, IORESOURCE_REG, 0); |
| 121 | if (!res) { |
| 122 | dev_err(&pdev->dev, "No REG resource for mode control!\n"); |
| 123 | ret = -ENXIO; |
| 124 | goto out; |
| 125 | } |
| 126 | data->reg_mode_cntl = res->start; |
| 127 | res = platform_get_resource(pdev, IORESOURCE_REG, 1); |
| 128 | if (!res) { |
| 129 | dev_err(&pdev->dev, "No REG resource for control!\n"); |
| 130 | ret = -ENXIO; |
| 131 | goto out; |
| 132 | } |
| 133 | data->reg_cntl = res->start; |
| 134 | |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 135 | data->chip = chip; |
| 136 | data->current_brightness = 0; |
| 137 | |
Matthew Garrett | a19a6ee | 2010-02-17 16:39:44 -0500 | [diff] [blame] | 138 | memset(&props, 0, sizeof(struct backlight_properties)); |
Matthew Garrett | bb7ca74 | 2011-03-22 16:30:21 -0700 | [diff] [blame] | 139 | props.type = BACKLIGHT_RAW; |
Matthew Garrett | a19a6ee | 2010-02-17 16:39:44 -0500 | [diff] [blame] | 140 | props.max_brightness = MAX_BRIGHTNESS; |
Haojian Zhuang | 63b501e | 2012-09-17 12:19:04 +0800 | [diff] [blame] | 141 | bl = backlight_device_register("max8925-backlight", &pdev->dev, data, |
Matthew Garrett | a19a6ee | 2010-02-17 16:39:44 -0500 | [diff] [blame] | 142 | &max8925_backlight_ops, &props); |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 143 | if (IS_ERR(bl)) { |
| 144 | dev_err(&pdev->dev, "failed to register backlight\n"); |
Haojian Zhuang | 63b501e | 2012-09-17 12:19:04 +0800 | [diff] [blame] | 145 | ret = PTR_ERR(bl); |
| 146 | goto out; |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 147 | } |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 148 | bl->props.brightness = MAX_BRIGHTNESS; |
| 149 | |
| 150 | platform_set_drvdata(pdev, bl); |
| 151 | |
| 152 | value = 0; |
Haojian Zhuang | 63b501e | 2012-09-17 12:19:04 +0800 | [diff] [blame] | 153 | if (pdata) { |
| 154 | if (pdata->lxw_scl) |
| 155 | value |= (1 << 7); |
| 156 | if (pdata->lxw_freq) |
| 157 | value |= (LWX_FREQ(pdata->lxw_freq) << 4); |
| 158 | if (pdata->dual_string) |
| 159 | value |= (1 << 1); |
| 160 | } |
| 161 | ret = max8925_set_bits(chip->i2c, data->reg_mode_cntl, 0xfe, value); |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 162 | if (ret < 0) |
Haojian Zhuang | 63b501e | 2012-09-17 12:19:04 +0800 | [diff] [blame] | 163 | goto out_brt; |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 164 | |
| 165 | backlight_update_status(bl); |
| 166 | return 0; |
Haojian Zhuang | 63b501e | 2012-09-17 12:19:04 +0800 | [diff] [blame] | 167 | out_brt: |
Axel Lin | 146e10a | 2010-05-10 09:27:34 +0800 | [diff] [blame] | 168 | backlight_device_unregister(bl); |
Haojian Zhuang | 63b501e | 2012-09-17 12:19:04 +0800 | [diff] [blame] | 169 | out: |
| 170 | devm_kfree(&pdev->dev, data); |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 171 | return ret; |
| 172 | } |
| 173 | |
Bill Pemberton | 7e4b9d0 | 2012-11-19 13:26:34 -0500 | [diff] [blame] | 174 | static int max8925_backlight_remove(struct platform_device *pdev) |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 175 | { |
| 176 | struct backlight_device *bl = platform_get_drvdata(pdev); |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 177 | |
| 178 | backlight_device_unregister(bl); |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 179 | return 0; |
| 180 | } |
| 181 | |
| 182 | static struct platform_driver max8925_backlight_driver = { |
| 183 | .driver = { |
| 184 | .name = "max8925-backlight", |
| 185 | .owner = THIS_MODULE, |
| 186 | }, |
| 187 | .probe = max8925_backlight_probe, |
Bill Pemberton | d1723fa | 2012-11-19 13:21:09 -0500 | [diff] [blame] | 188 | .remove = max8925_backlight_remove, |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 189 | }; |
| 190 | |
Axel Lin | 81178e0 | 2012-01-10 15:09:11 -0800 | [diff] [blame] | 191 | module_platform_driver(max8925_backlight_driver); |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 192 | |
| 193 | MODULE_DESCRIPTION("Backlight Driver for Maxim MAX8925"); |
| 194 | MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>"); |
| 195 | MODULE_LICENSE("GPL"); |
| 196 | MODULE_ALIAS("platform:max8925-backlight"); |