Mark Brown | a4f3d55 | 2009-09-05 14:09:20 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Backlight driver for Wolfson Microelectronics WM831x PMICs |
| 3 | * |
| 4 | * Copyright 2009 Wolfson Microelectonics plc |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License version 2 as |
| 8 | * published by the Free Software Foundation. |
| 9 | */ |
| 10 | |
| 11 | #include <linux/kernel.h> |
| 12 | #include <linux/init.h> |
| 13 | #include <linux/platform_device.h> |
| 14 | #include <linux/fb.h> |
| 15 | #include <linux/backlight.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 16 | #include <linux/slab.h> |
Mark Brown | a4f3d55 | 2009-09-05 14:09:20 +0100 | [diff] [blame] | 17 | |
| 18 | #include <linux/mfd/wm831x/core.h> |
| 19 | #include <linux/mfd/wm831x/pdata.h> |
| 20 | #include <linux/mfd/wm831x/regulator.h> |
| 21 | |
| 22 | struct wm831x_backlight_data { |
| 23 | struct wm831x *wm831x; |
| 24 | int isink_reg; |
| 25 | int current_brightness; |
| 26 | }; |
| 27 | |
| 28 | static int wm831x_backlight_set(struct backlight_device *bl, int brightness) |
| 29 | { |
| 30 | struct wm831x_backlight_data *data = bl_get_data(bl); |
| 31 | struct wm831x *wm831x = data->wm831x; |
| 32 | int power_up = !data->current_brightness && brightness; |
| 33 | int power_down = data->current_brightness && !brightness; |
| 34 | int ret; |
| 35 | |
| 36 | if (power_up) { |
| 37 | /* Enable the ISINK */ |
| 38 | ret = wm831x_set_bits(wm831x, data->isink_reg, |
| 39 | WM831X_CS1_ENA, WM831X_CS1_ENA); |
| 40 | if (ret < 0) |
| 41 | goto err; |
| 42 | |
| 43 | /* Enable the DC-DC */ |
| 44 | ret = wm831x_set_bits(wm831x, WM831X_DCDC_ENABLE, |
| 45 | WM831X_DC4_ENA, WM831X_DC4_ENA); |
| 46 | if (ret < 0) |
| 47 | goto err; |
| 48 | } |
| 49 | |
| 50 | if (power_down) { |
| 51 | /* DCDC first */ |
| 52 | ret = wm831x_set_bits(wm831x, WM831X_DCDC_ENABLE, |
| 53 | WM831X_DC4_ENA, 0); |
| 54 | if (ret < 0) |
| 55 | goto err; |
| 56 | |
| 57 | /* ISINK */ |
| 58 | ret = wm831x_set_bits(wm831x, data->isink_reg, |
| 59 | WM831X_CS1_DRIVE | WM831X_CS1_ENA, 0); |
| 60 | if (ret < 0) |
| 61 | goto err; |
| 62 | } |
| 63 | |
| 64 | /* Set the new brightness */ |
| 65 | ret = wm831x_set_bits(wm831x, data->isink_reg, |
| 66 | WM831X_CS1_ISEL_MASK, brightness); |
| 67 | if (ret < 0) |
| 68 | goto err; |
| 69 | |
| 70 | if (power_up) { |
| 71 | /* Drive current through the ISINK */ |
| 72 | ret = wm831x_set_bits(wm831x, data->isink_reg, |
| 73 | WM831X_CS1_DRIVE, WM831X_CS1_DRIVE); |
| 74 | if (ret < 0) |
| 75 | return ret; |
| 76 | } |
| 77 | |
| 78 | data->current_brightness = brightness; |
| 79 | |
| 80 | return 0; |
| 81 | |
| 82 | err: |
| 83 | /* If we were in the middle of a power transition always shut down |
| 84 | * for safety. |
| 85 | */ |
| 86 | if (power_up || power_down) { |
| 87 | wm831x_set_bits(wm831x, WM831X_DCDC_ENABLE, WM831X_DC4_ENA, 0); |
| 88 | wm831x_set_bits(wm831x, data->isink_reg, WM831X_CS1_ENA, 0); |
| 89 | } |
| 90 | |
| 91 | return ret; |
| 92 | } |
| 93 | |
| 94 | static int wm831x_backlight_update_status(struct backlight_device *bl) |
| 95 | { |
| 96 | int brightness = bl->props.brightness; |
| 97 | |
| 98 | if (bl->props.power != FB_BLANK_UNBLANK) |
| 99 | brightness = 0; |
| 100 | |
| 101 | if (bl->props.fb_blank != FB_BLANK_UNBLANK) |
| 102 | brightness = 0; |
| 103 | |
| 104 | if (bl->props.state & BL_CORE_SUSPENDED) |
| 105 | brightness = 0; |
| 106 | |
| 107 | return wm831x_backlight_set(bl, brightness); |
| 108 | } |
| 109 | |
| 110 | static int wm831x_backlight_get_brightness(struct backlight_device *bl) |
| 111 | { |
| 112 | struct wm831x_backlight_data *data = bl_get_data(bl); |
| 113 | return data->current_brightness; |
| 114 | } |
| 115 | |
Emese Revfy | 9905a43 | 2009-12-14 00:58:57 +0100 | [diff] [blame] | 116 | static const struct backlight_ops wm831x_backlight_ops = { |
Mark Brown | a4f3d55 | 2009-09-05 14:09:20 +0100 | [diff] [blame] | 117 | .options = BL_CORE_SUSPENDRESUME, |
| 118 | .update_status = wm831x_backlight_update_status, |
| 119 | .get_brightness = wm831x_backlight_get_brightness, |
| 120 | }; |
| 121 | |
| 122 | static int wm831x_backlight_probe(struct platform_device *pdev) |
| 123 | { |
| 124 | struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent); |
| 125 | struct wm831x_pdata *wm831x_pdata; |
| 126 | struct wm831x_backlight_pdata *pdata; |
| 127 | struct wm831x_backlight_data *data; |
| 128 | struct backlight_device *bl; |
Matthew Garrett | a19a6ee | 2010-02-17 16:39:44 -0500 | [diff] [blame] | 129 | struct backlight_properties props; |
Mark Brown | a4f3d55 | 2009-09-05 14:09:20 +0100 | [diff] [blame] | 130 | int ret, i, max_isel, isink_reg, dcdc_cfg; |
| 131 | |
| 132 | /* We need platform data */ |
| 133 | if (pdev->dev.parent->platform_data) { |
| 134 | wm831x_pdata = pdev->dev.parent->platform_data; |
| 135 | pdata = wm831x_pdata->backlight; |
| 136 | } else { |
| 137 | pdata = NULL; |
| 138 | } |
| 139 | |
| 140 | if (!pdata) { |
| 141 | dev_err(&pdev->dev, "No platform data supplied\n"); |
| 142 | return -EINVAL; |
| 143 | } |
| 144 | |
| 145 | /* Figure out the maximum current we can use */ |
| 146 | for (i = 0; i < WM831X_ISINK_MAX_ISEL; i++) { |
| 147 | if (wm831x_isinkv_values[i] > pdata->max_uA) |
| 148 | break; |
| 149 | } |
| 150 | |
| 151 | if (i == 0) { |
| 152 | dev_err(&pdev->dev, "Invalid max_uA: %duA\n", pdata->max_uA); |
| 153 | return -EINVAL; |
| 154 | } |
| 155 | max_isel = i - 1; |
| 156 | |
| 157 | if (pdata->max_uA != wm831x_isinkv_values[max_isel]) |
| 158 | dev_warn(&pdev->dev, |
| 159 | "Maximum current is %duA not %duA as requested\n", |
| 160 | wm831x_isinkv_values[max_isel], pdata->max_uA); |
| 161 | |
| 162 | switch (pdata->isink) { |
| 163 | case 1: |
| 164 | isink_reg = WM831X_CURRENT_SINK_1; |
| 165 | dcdc_cfg = 0; |
| 166 | break; |
| 167 | case 2: |
| 168 | isink_reg = WM831X_CURRENT_SINK_2; |
| 169 | dcdc_cfg = WM831X_DC4_FBSRC; |
| 170 | break; |
| 171 | default: |
| 172 | dev_err(&pdev->dev, "Invalid ISINK %d\n", pdata->isink); |
| 173 | return -EINVAL; |
| 174 | } |
| 175 | |
| 176 | /* Configure the ISINK to use for feedback */ |
| 177 | ret = wm831x_reg_unlock(wm831x); |
| 178 | if (ret < 0) |
| 179 | return ret; |
| 180 | |
| 181 | ret = wm831x_set_bits(wm831x, WM831X_DC4_CONTROL, WM831X_DC4_FBSRC, |
| 182 | dcdc_cfg); |
| 183 | |
| 184 | wm831x_reg_lock(wm831x); |
| 185 | if (ret < 0) |
| 186 | return ret; |
| 187 | |
| 188 | data = kzalloc(sizeof(*data), GFP_KERNEL); |
| 189 | if (data == NULL) |
| 190 | return -ENOMEM; |
| 191 | |
| 192 | data->wm831x = wm831x; |
| 193 | data->current_brightness = 0; |
| 194 | data->isink_reg = isink_reg; |
| 195 | |
Matthew Garrett | a19a6ee | 2010-02-17 16:39:44 -0500 | [diff] [blame] | 196 | props.max_brightness = max_isel; |
| 197 | bl = backlight_device_register("wm831x", &pdev->dev, data, |
| 198 | &wm831x_backlight_ops, &props); |
Mark Brown | a4f3d55 | 2009-09-05 14:09:20 +0100 | [diff] [blame] | 199 | if (IS_ERR(bl)) { |
| 200 | dev_err(&pdev->dev, "failed to register backlight\n"); |
| 201 | kfree(data); |
| 202 | return PTR_ERR(bl); |
| 203 | } |
| 204 | |
Mark Brown | a4f3d55 | 2009-09-05 14:09:20 +0100 | [diff] [blame] | 205 | bl->props.brightness = max_isel; |
| 206 | |
| 207 | platform_set_drvdata(pdev, bl); |
| 208 | |
| 209 | /* Disable the DCDC if it was started so we can bootstrap */ |
| 210 | wm831x_set_bits(wm831x, WM831X_DCDC_ENABLE, WM831X_DC4_ENA, 0); |
| 211 | |
| 212 | |
| 213 | backlight_update_status(bl); |
| 214 | |
| 215 | return 0; |
| 216 | } |
| 217 | |
| 218 | static int wm831x_backlight_remove(struct platform_device *pdev) |
| 219 | { |
| 220 | struct backlight_device *bl = platform_get_drvdata(pdev); |
| 221 | struct wm831x_backlight_data *data = bl_get_data(bl); |
| 222 | |
| 223 | backlight_device_unregister(bl); |
| 224 | kfree(data); |
| 225 | return 0; |
| 226 | } |
| 227 | |
| 228 | static struct platform_driver wm831x_backlight_driver = { |
| 229 | .driver = { |
| 230 | .name = "wm831x-backlight", |
| 231 | .owner = THIS_MODULE, |
| 232 | }, |
| 233 | .probe = wm831x_backlight_probe, |
| 234 | .remove = wm831x_backlight_remove, |
| 235 | }; |
| 236 | |
| 237 | static int __init wm831x_backlight_init(void) |
| 238 | { |
| 239 | return platform_driver_register(&wm831x_backlight_driver); |
| 240 | } |
| 241 | module_init(wm831x_backlight_init); |
| 242 | |
| 243 | static void __exit wm831x_backlight_exit(void) |
| 244 | { |
| 245 | platform_driver_unregister(&wm831x_backlight_driver); |
| 246 | } |
| 247 | module_exit(wm831x_backlight_exit); |
| 248 | |
| 249 | MODULE_DESCRIPTION("Backlight Driver for WM831x PMICs"); |
| 250 | MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com"); |
| 251 | MODULE_LICENSE("GPL"); |
| 252 | MODULE_ALIAS("platform:wm831x-backlight"); |