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 | |
Olof Johansson | 515c096 | 2013-07-24 08:42:27 -0700 | [diff] [blame] | 104 | static void max8925_backlight_dt_init(struct platform_device *pdev) |
Qing Xu | 47ec340 | 2013-02-04 23:40:45 +0800 | [diff] [blame] | 105 | { |
| 106 | struct device_node *nproot = pdev->dev.parent->of_node, *np; |
Olof Johansson | 515c096 | 2013-07-24 08:42:27 -0700 | [diff] [blame] | 107 | struct max8925_backlight_pdata *pdata; |
| 108 | u32 val; |
Qing Xu | 47ec340 | 2013-02-04 23:40:45 +0800 | [diff] [blame] | 109 | |
Olof Johansson | 515c096 | 2013-07-24 08:42:27 -0700 | [diff] [blame] | 110 | if (!nproot || !IS_ENABLED(CONFIG_OF)) |
| 111 | return; |
| 112 | |
| 113 | pdata = devm_kzalloc(&pdev->dev, |
| 114 | sizeof(struct max8925_backlight_pdata), |
| 115 | GFP_KERNEL); |
| 116 | if (!pdata) |
| 117 | return; |
| 118 | |
Qing Xu | 47ec340 | 2013-02-04 23:40:45 +0800 | [diff] [blame] | 119 | np = of_find_node_by_name(nproot, "backlight"); |
| 120 | if (!np) { |
| 121 | dev_err(&pdev->dev, "failed to find backlight node\n"); |
Olof Johansson | 515c096 | 2013-07-24 08:42:27 -0700 | [diff] [blame] | 122 | return; |
Qing Xu | 47ec340 | 2013-02-04 23:40:45 +0800 | [diff] [blame] | 123 | } |
| 124 | |
Olof Johansson | 515c096 | 2013-07-24 08:42:27 -0700 | [diff] [blame] | 125 | if (!of_property_read_u32(np, "maxim,max8925-dual-string", &val)) |
| 126 | pdata->dual_string = val; |
| 127 | |
| 128 | pdev->dev.platform_data = pdata; |
Qing Xu | 47ec340 | 2013-02-04 23:40:45 +0800 | [diff] [blame] | 129 | } |
Qing Xu | 47ec340 | 2013-02-04 23:40:45 +0800 | [diff] [blame] | 130 | |
Bill Pemberton | 1b9e450 | 2012-11-19 13:21:46 -0500 | [diff] [blame] | 131 | static int max8925_backlight_probe(struct platform_device *pdev) |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 132 | { |
| 133 | struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent); |
Olof Johansson | 515c096 | 2013-07-24 08:42:27 -0700 | [diff] [blame] | 134 | struct max8925_backlight_pdata *pdata; |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 135 | struct max8925_backlight_data *data; |
| 136 | struct backlight_device *bl; |
Matthew Garrett | a19a6ee | 2010-02-17 16:39:44 -0500 | [diff] [blame] | 137 | struct backlight_properties props; |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 138 | struct resource *res; |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 139 | unsigned char value; |
Haojian Zhuang | 63b501e | 2012-09-17 12:19:04 +0800 | [diff] [blame] | 140 | int ret = 0; |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 141 | |
Julia Lawall | ce96922 | 2012-03-23 15:02:00 -0700 | [diff] [blame] | 142 | data = devm_kzalloc(&pdev->dev, sizeof(struct max8925_backlight_data), |
| 143 | GFP_KERNEL); |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 144 | if (data == NULL) |
| 145 | return -ENOMEM; |
Haojian Zhuang | 63b501e | 2012-09-17 12:19:04 +0800 | [diff] [blame] | 146 | |
| 147 | res = platform_get_resource(pdev, IORESOURCE_REG, 0); |
| 148 | if (!res) { |
| 149 | dev_err(&pdev->dev, "No REG resource for mode control!\n"); |
Jingoo Han | 2c114cb | 2012-12-17 16:00:58 -0800 | [diff] [blame] | 150 | return -ENXIO; |
Haojian Zhuang | 63b501e | 2012-09-17 12:19:04 +0800 | [diff] [blame] | 151 | } |
| 152 | data->reg_mode_cntl = res->start; |
| 153 | res = platform_get_resource(pdev, IORESOURCE_REG, 1); |
| 154 | if (!res) { |
| 155 | dev_err(&pdev->dev, "No REG resource for control!\n"); |
Jingoo Han | 2c114cb | 2012-12-17 16:00:58 -0800 | [diff] [blame] | 156 | return -ENXIO; |
Haojian Zhuang | 63b501e | 2012-09-17 12:19:04 +0800 | [diff] [blame] | 157 | } |
| 158 | data->reg_cntl = res->start; |
| 159 | |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 160 | data->chip = chip; |
| 161 | data->current_brightness = 0; |
| 162 | |
Matthew Garrett | a19a6ee | 2010-02-17 16:39:44 -0500 | [diff] [blame] | 163 | memset(&props, 0, sizeof(struct backlight_properties)); |
Matthew Garrett | bb7ca74 | 2011-03-22 16:30:21 -0700 | [diff] [blame] | 164 | props.type = BACKLIGHT_RAW; |
Matthew Garrett | a19a6ee | 2010-02-17 16:39:44 -0500 | [diff] [blame] | 165 | props.max_brightness = MAX_BRIGHTNESS; |
Jingoo Han | 18d9dbc | 2013-11-12 15:09:21 -0800 | [diff] [blame] | 166 | bl = devm_backlight_device_register(&pdev->dev, "max8925-backlight", |
| 167 | &pdev->dev, data, |
Matthew Garrett | a19a6ee | 2010-02-17 16:39:44 -0500 | [diff] [blame] | 168 | &max8925_backlight_ops, &props); |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 169 | if (IS_ERR(bl)) { |
| 170 | dev_err(&pdev->dev, "failed to register backlight\n"); |
Jingoo Han | 2c114cb | 2012-12-17 16:00:58 -0800 | [diff] [blame] | 171 | return PTR_ERR(bl); |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 172 | } |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 173 | bl->props.brightness = MAX_BRIGHTNESS; |
| 174 | |
| 175 | platform_set_drvdata(pdev, bl); |
| 176 | |
| 177 | value = 0; |
Olof Johansson | 515c096 | 2013-07-24 08:42:27 -0700 | [diff] [blame] | 178 | if (!pdev->dev.platform_data) |
| 179 | max8925_backlight_dt_init(pdev); |
Qing Xu | 47ec340 | 2013-02-04 23:40:45 +0800 | [diff] [blame] | 180 | |
Olof Johansson | 515c096 | 2013-07-24 08:42:27 -0700 | [diff] [blame] | 181 | pdata = pdev->dev.platform_data; |
Haojian Zhuang | 63b501e | 2012-09-17 12:19:04 +0800 | [diff] [blame] | 182 | if (pdata) { |
| 183 | if (pdata->lxw_scl) |
| 184 | value |= (1 << 7); |
| 185 | if (pdata->lxw_freq) |
| 186 | value |= (LWX_FREQ(pdata->lxw_freq) << 4); |
| 187 | if (pdata->dual_string) |
| 188 | value |= (1 << 1); |
| 189 | } |
| 190 | ret = max8925_set_bits(chip->i2c, data->reg_mode_cntl, 0xfe, value); |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 191 | if (ret < 0) |
Jingoo Han | 18d9dbc | 2013-11-12 15:09:21 -0800 | [diff] [blame] | 192 | return ret; |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 193 | backlight_update_status(bl); |
| 194 | return 0; |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 195 | } |
| 196 | |
| 197 | static struct platform_driver max8925_backlight_driver = { |
| 198 | .driver = { |
| 199 | .name = "max8925-backlight", |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 200 | }, |
| 201 | .probe = max8925_backlight_probe, |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 202 | }; |
| 203 | |
Axel Lin | 81178e0 | 2012-01-10 15:09:11 -0800 | [diff] [blame] | 204 | module_platform_driver(max8925_backlight_driver); |
Haojian Zhuang | 4f811ef | 2009-12-18 10:01:45 -0500 | [diff] [blame] | 205 | |
| 206 | MODULE_DESCRIPTION("Backlight Driver for Maxim MAX8925"); |
| 207 | MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>"); |
| 208 | MODULE_LICENSE("GPL"); |
| 209 | MODULE_ALIAS("platform:max8925-backlight"); |