Guennadi Liakhovetski | de474b5b | 2013-02-21 16:43:59 -0800 | [diff] [blame] | 1 | /* |
| 2 | * AS3711 PMIC backlight driver, using DCDC Step Up Converters |
| 3 | * |
| 4 | * Copyright (C) 2012 Renesas Electronics Corporation |
| 5 | * Author: Guennadi Liakhovetski, <g.liakhovetski@gmx.de> |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the version 2 of the GNU General Public License as |
| 9 | * published by the Free Software Foundation |
| 10 | */ |
| 11 | |
| 12 | #include <linux/backlight.h> |
| 13 | #include <linux/delay.h> |
| 14 | #include <linux/device.h> |
| 15 | #include <linux/err.h> |
| 16 | #include <linux/fb.h> |
| 17 | #include <linux/kernel.h> |
| 18 | #include <linux/mfd/as3711.h> |
| 19 | #include <linux/module.h> |
| 20 | #include <linux/platform_device.h> |
| 21 | #include <linux/regmap.h> |
| 22 | #include <linux/slab.h> |
| 23 | |
| 24 | enum as3711_bl_type { |
| 25 | AS3711_BL_SU1, |
| 26 | AS3711_BL_SU2, |
| 27 | }; |
| 28 | |
| 29 | struct as3711_bl_data { |
| 30 | bool powered; |
| 31 | const char *fb_name; |
| 32 | struct device *fb_dev; |
| 33 | enum as3711_bl_type type; |
| 34 | int brightness; |
| 35 | struct backlight_device *bl; |
| 36 | }; |
| 37 | |
| 38 | struct as3711_bl_supply { |
| 39 | struct as3711_bl_data su1; |
| 40 | struct as3711_bl_data su2; |
| 41 | const struct as3711_bl_pdata *pdata; |
| 42 | struct as3711 *as3711; |
| 43 | }; |
| 44 | |
| 45 | static struct as3711_bl_supply *to_supply(struct as3711_bl_data *su) |
| 46 | { |
| 47 | switch (su->type) { |
| 48 | case AS3711_BL_SU1: |
| 49 | return container_of(su, struct as3711_bl_supply, su1); |
| 50 | case AS3711_BL_SU2: |
| 51 | return container_of(su, struct as3711_bl_supply, su2); |
| 52 | } |
| 53 | return NULL; |
| 54 | } |
| 55 | |
| 56 | static int as3711_set_brightness_auto_i(struct as3711_bl_data *data, |
| 57 | unsigned int brightness) |
| 58 | { |
| 59 | struct as3711_bl_supply *supply = to_supply(data); |
| 60 | struct as3711 *as3711 = supply->as3711; |
| 61 | const struct as3711_bl_pdata *pdata = supply->pdata; |
| 62 | int ret = 0; |
| 63 | |
| 64 | /* Only all equal current values are supported */ |
| 65 | if (pdata->su2_auto_curr1) |
| 66 | ret = regmap_write(as3711->regmap, AS3711_CURR1_VALUE, |
| 67 | brightness); |
| 68 | if (!ret && pdata->su2_auto_curr2) |
| 69 | ret = regmap_write(as3711->regmap, AS3711_CURR2_VALUE, |
| 70 | brightness); |
| 71 | if (!ret && pdata->su2_auto_curr3) |
| 72 | ret = regmap_write(as3711->regmap, AS3711_CURR3_VALUE, |
| 73 | brightness); |
| 74 | |
| 75 | return ret; |
| 76 | } |
| 77 | |
| 78 | static int as3711_set_brightness_v(struct as3711 *as3711, |
| 79 | unsigned int brightness, |
| 80 | unsigned int reg) |
| 81 | { |
| 82 | if (brightness > 31) |
| 83 | return -EINVAL; |
| 84 | |
| 85 | return regmap_update_bits(as3711->regmap, reg, 0xf0, |
| 86 | brightness << 4); |
| 87 | } |
| 88 | |
| 89 | static int as3711_bl_su2_reset(struct as3711_bl_supply *supply) |
| 90 | { |
| 91 | struct as3711 *as3711 = supply->as3711; |
| 92 | int ret = regmap_update_bits(as3711->regmap, AS3711_STEPUP_CONTROL_5, |
| 93 | 3, supply->pdata->su2_fbprot); |
| 94 | if (!ret) |
| 95 | ret = regmap_update_bits(as3711->regmap, |
| 96 | AS3711_STEPUP_CONTROL_2, 1, 0); |
| 97 | if (!ret) |
| 98 | ret = regmap_update_bits(as3711->regmap, |
| 99 | AS3711_STEPUP_CONTROL_2, 1, 1); |
| 100 | return ret; |
| 101 | } |
| 102 | |
| 103 | /* |
| 104 | * Someone with less fragile or less expensive hardware could try to simplify |
| 105 | * the brightness adjustment procedure. |
| 106 | */ |
| 107 | static int as3711_bl_update_status(struct backlight_device *bl) |
| 108 | { |
| 109 | struct as3711_bl_data *data = bl_get_data(bl); |
| 110 | struct as3711_bl_supply *supply = to_supply(data); |
| 111 | struct as3711 *as3711 = supply->as3711; |
| 112 | int brightness = bl->props.brightness; |
| 113 | int ret = 0; |
| 114 | |
| 115 | dev_dbg(&bl->dev, "%s(): brightness %u, pwr %x, blank %x, state %x\n", |
| 116 | __func__, bl->props.brightness, bl->props.power, |
| 117 | bl->props.fb_blank, bl->props.state); |
| 118 | |
| 119 | if (bl->props.power != FB_BLANK_UNBLANK || |
| 120 | bl->props.fb_blank != FB_BLANK_UNBLANK || |
| 121 | bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK)) |
| 122 | brightness = 0; |
| 123 | |
| 124 | if (data->type == AS3711_BL_SU1) { |
| 125 | ret = as3711_set_brightness_v(as3711, brightness, |
| 126 | AS3711_STEPUP_CONTROL_1); |
| 127 | } else { |
| 128 | const struct as3711_bl_pdata *pdata = supply->pdata; |
| 129 | |
| 130 | switch (pdata->su2_feedback) { |
| 131 | case AS3711_SU2_VOLTAGE: |
| 132 | ret = as3711_set_brightness_v(as3711, brightness, |
| 133 | AS3711_STEPUP_CONTROL_2); |
| 134 | break; |
| 135 | case AS3711_SU2_CURR_AUTO: |
| 136 | ret = as3711_set_brightness_auto_i(data, brightness / 4); |
| 137 | if (ret < 0) |
| 138 | return ret; |
| 139 | if (brightness) { |
| 140 | ret = as3711_bl_su2_reset(supply); |
| 141 | if (ret < 0) |
| 142 | return ret; |
| 143 | udelay(500); |
| 144 | ret = as3711_set_brightness_auto_i(data, brightness); |
| 145 | } else { |
| 146 | ret = regmap_update_bits(as3711->regmap, |
| 147 | AS3711_STEPUP_CONTROL_2, 1, 0); |
| 148 | } |
| 149 | break; |
| 150 | /* Manual one current feedback pin below */ |
| 151 | case AS3711_SU2_CURR1: |
| 152 | ret = regmap_write(as3711->regmap, AS3711_CURR1_VALUE, |
| 153 | brightness); |
| 154 | break; |
| 155 | case AS3711_SU2_CURR2: |
| 156 | ret = regmap_write(as3711->regmap, AS3711_CURR2_VALUE, |
| 157 | brightness); |
| 158 | break; |
| 159 | case AS3711_SU2_CURR3: |
| 160 | ret = regmap_write(as3711->regmap, AS3711_CURR3_VALUE, |
| 161 | brightness); |
| 162 | break; |
| 163 | default: |
| 164 | ret = -EINVAL; |
| 165 | } |
| 166 | } |
| 167 | if (!ret) |
| 168 | data->brightness = brightness; |
| 169 | |
| 170 | return ret; |
| 171 | } |
| 172 | |
| 173 | static int as3711_bl_get_brightness(struct backlight_device *bl) |
| 174 | { |
| 175 | struct as3711_bl_data *data = bl_get_data(bl); |
| 176 | |
| 177 | return data->brightness; |
| 178 | } |
| 179 | |
| 180 | static const struct backlight_ops as3711_bl_ops = { |
| 181 | .update_status = as3711_bl_update_status, |
| 182 | .get_brightness = as3711_bl_get_brightness, |
| 183 | }; |
| 184 | |
| 185 | static int as3711_bl_init_su2(struct as3711_bl_supply *supply) |
| 186 | { |
| 187 | struct as3711 *as3711 = supply->as3711; |
| 188 | const struct as3711_bl_pdata *pdata = supply->pdata; |
| 189 | u8 ctl = 0; |
| 190 | int ret; |
| 191 | |
| 192 | dev_dbg(as3711->dev, "%s(): use %u\n", __func__, pdata->su2_feedback); |
| 193 | |
| 194 | /* Turn SU2 off */ |
| 195 | ret = regmap_write(as3711->regmap, AS3711_STEPUP_CONTROL_2, 0); |
| 196 | if (ret < 0) |
| 197 | return ret; |
| 198 | |
| 199 | switch (pdata->su2_feedback) { |
| 200 | case AS3711_SU2_VOLTAGE: |
| 201 | ret = regmap_update_bits(as3711->regmap, AS3711_STEPUP_CONTROL_4, 3, 0); |
| 202 | break; |
| 203 | case AS3711_SU2_CURR1: |
| 204 | ctl = 1; |
| 205 | ret = regmap_update_bits(as3711->regmap, AS3711_STEPUP_CONTROL_4, 3, 1); |
| 206 | break; |
| 207 | case AS3711_SU2_CURR2: |
| 208 | ctl = 4; |
| 209 | ret = regmap_update_bits(as3711->regmap, AS3711_STEPUP_CONTROL_4, 3, 2); |
| 210 | break; |
| 211 | case AS3711_SU2_CURR3: |
| 212 | ctl = 0x10; |
| 213 | ret = regmap_update_bits(as3711->regmap, AS3711_STEPUP_CONTROL_4, 3, 3); |
| 214 | break; |
| 215 | case AS3711_SU2_CURR_AUTO: |
| 216 | if (pdata->su2_auto_curr1) |
| 217 | ctl = 2; |
| 218 | if (pdata->su2_auto_curr2) |
| 219 | ctl |= 8; |
| 220 | if (pdata->su2_auto_curr3) |
| 221 | ctl |= 0x20; |
| 222 | ret = 0; |
| 223 | break; |
| 224 | default: |
| 225 | return -EINVAL; |
| 226 | } |
| 227 | |
| 228 | if (!ret) |
| 229 | ret = regmap_write(as3711->regmap, AS3711_CURR_CONTROL, ctl); |
| 230 | |
| 231 | return ret; |
| 232 | } |
| 233 | |
| 234 | static int as3711_bl_register(struct platform_device *pdev, |
| 235 | unsigned int max_brightness, struct as3711_bl_data *su) |
| 236 | { |
| 237 | struct backlight_properties props = {.type = BACKLIGHT_RAW,}; |
| 238 | struct backlight_device *bl; |
| 239 | |
| 240 | /* max tuning I = 31uA for voltage- and 38250uA for current-feedback */ |
| 241 | props.max_brightness = max_brightness; |
| 242 | |
Jingoo Han | 83dedc0 | 2013-11-12 15:09:10 -0800 | [diff] [blame] | 243 | bl = devm_backlight_device_register(&pdev->dev, |
| 244 | su->type == AS3711_BL_SU1 ? |
Guennadi Liakhovetski | de474b5b | 2013-02-21 16:43:59 -0800 | [diff] [blame] | 245 | "as3711-su1" : "as3711-su2", |
| 246 | &pdev->dev, su, |
| 247 | &as3711_bl_ops, &props); |
| 248 | if (IS_ERR(bl)) { |
| 249 | dev_err(&pdev->dev, "failed to register backlight\n"); |
| 250 | return PTR_ERR(bl); |
| 251 | } |
| 252 | |
| 253 | bl->props.brightness = props.max_brightness; |
| 254 | |
| 255 | backlight_update_status(bl); |
| 256 | |
| 257 | su->bl = bl; |
| 258 | |
| 259 | return 0; |
| 260 | } |
| 261 | |
Guennadi Liakhovetski | 59eb2b5 | 2013-04-29 16:17:55 -0700 | [diff] [blame] | 262 | static int as3711_backlight_parse_dt(struct device *dev) |
| 263 | { |
| 264 | struct as3711_bl_pdata *pdata = dev_get_platdata(dev); |
| 265 | struct device_node *bl = |
| 266 | of_find_node_by_name(dev->parent->of_node, "backlight"), *fb; |
| 267 | int ret; |
| 268 | |
| 269 | if (!bl) { |
| 270 | dev_dbg(dev, "backlight node not found\n"); |
| 271 | return -ENODEV; |
| 272 | } |
| 273 | |
| 274 | fb = of_parse_phandle(bl, "su1-dev", 0); |
| 275 | if (fb) { |
| 276 | pdata->su1_fb = fb->full_name; |
| 277 | |
| 278 | ret = of_property_read_u32(bl, "su1-max-uA", &pdata->su1_max_uA); |
| 279 | if (pdata->su1_max_uA <= 0) |
| 280 | ret = -EINVAL; |
| 281 | if (ret < 0) |
| 282 | return ret; |
| 283 | } |
| 284 | |
| 285 | fb = of_parse_phandle(bl, "su2-dev", 0); |
| 286 | if (fb) { |
| 287 | int count = 0; |
| 288 | |
| 289 | pdata->su2_fb = fb->full_name; |
| 290 | |
| 291 | ret = of_property_read_u32(bl, "su2-max-uA", &pdata->su2_max_uA); |
| 292 | if (pdata->su2_max_uA <= 0) |
| 293 | ret = -EINVAL; |
| 294 | if (ret < 0) |
| 295 | return ret; |
| 296 | |
| 297 | if (of_find_property(bl, "su2-feedback-voltage", NULL)) { |
| 298 | pdata->su2_feedback = AS3711_SU2_VOLTAGE; |
| 299 | count++; |
| 300 | } |
| 301 | if (of_find_property(bl, "su2-feedback-curr1", NULL)) { |
| 302 | pdata->su2_feedback = AS3711_SU2_CURR1; |
| 303 | count++; |
| 304 | } |
| 305 | if (of_find_property(bl, "su2-feedback-curr2", NULL)) { |
| 306 | pdata->su2_feedback = AS3711_SU2_CURR2; |
| 307 | count++; |
| 308 | } |
| 309 | if (of_find_property(bl, "su2-feedback-curr3", NULL)) { |
| 310 | pdata->su2_feedback = AS3711_SU2_CURR3; |
| 311 | count++; |
| 312 | } |
| 313 | if (of_find_property(bl, "su2-feedback-curr-auto", NULL)) { |
| 314 | pdata->su2_feedback = AS3711_SU2_CURR_AUTO; |
| 315 | count++; |
| 316 | } |
| 317 | if (count != 1) |
| 318 | return -EINVAL; |
| 319 | |
| 320 | count = 0; |
| 321 | if (of_find_property(bl, "su2-fbprot-lx-sd4", NULL)) { |
| 322 | pdata->su2_fbprot = AS3711_SU2_LX_SD4; |
| 323 | count++; |
| 324 | } |
| 325 | if (of_find_property(bl, "su2-fbprot-gpio2", NULL)) { |
| 326 | pdata->su2_fbprot = AS3711_SU2_GPIO2; |
| 327 | count++; |
| 328 | } |
| 329 | if (of_find_property(bl, "su2-fbprot-gpio3", NULL)) { |
| 330 | pdata->su2_fbprot = AS3711_SU2_GPIO3; |
| 331 | count++; |
| 332 | } |
| 333 | if (of_find_property(bl, "su2-fbprot-gpio4", NULL)) { |
| 334 | pdata->su2_fbprot = AS3711_SU2_GPIO4; |
| 335 | count++; |
| 336 | } |
| 337 | if (count != 1) |
| 338 | return -EINVAL; |
| 339 | |
| 340 | count = 0; |
| 341 | if (of_find_property(bl, "su2-auto-curr1", NULL)) { |
| 342 | pdata->su2_auto_curr1 = true; |
| 343 | count++; |
| 344 | } |
| 345 | if (of_find_property(bl, "su2-auto-curr2", NULL)) { |
| 346 | pdata->su2_auto_curr2 = true; |
| 347 | count++; |
| 348 | } |
| 349 | if (of_find_property(bl, "su2-auto-curr3", NULL)) { |
| 350 | pdata->su2_auto_curr3 = true; |
| 351 | count++; |
| 352 | } |
| 353 | |
| 354 | /* |
| 355 | * At least one su2-auto-curr* must be specified iff |
| 356 | * AS3711_SU2_CURR_AUTO is used |
| 357 | */ |
| 358 | if (!count ^ (pdata->su2_feedback != AS3711_SU2_CURR_AUTO)) |
| 359 | return -EINVAL; |
| 360 | } |
| 361 | |
| 362 | return 0; |
| 363 | } |
| 364 | |
Guennadi Liakhovetski | de474b5b | 2013-02-21 16:43:59 -0800 | [diff] [blame] | 365 | static int as3711_backlight_probe(struct platform_device *pdev) |
| 366 | { |
| 367 | struct as3711_bl_pdata *pdata = dev_get_platdata(&pdev->dev); |
| 368 | struct as3711 *as3711 = dev_get_drvdata(pdev->dev.parent); |
| 369 | struct as3711_bl_supply *supply; |
| 370 | struct as3711_bl_data *su; |
| 371 | unsigned int max_brightness; |
| 372 | int ret; |
| 373 | |
Guennadi Liakhovetski | 59eb2b5 | 2013-04-29 16:17:55 -0700 | [diff] [blame] | 374 | if (!pdata) { |
Guennadi Liakhovetski | de474b5b | 2013-02-21 16:43:59 -0800 | [diff] [blame] | 375 | dev_err(&pdev->dev, "No platform data, exiting...\n"); |
| 376 | return -ENODEV; |
| 377 | } |
| 378 | |
Guennadi Liakhovetski | 59eb2b5 | 2013-04-29 16:17:55 -0700 | [diff] [blame] | 379 | if (pdev->dev.parent->of_node) { |
| 380 | ret = as3711_backlight_parse_dt(&pdev->dev); |
| 381 | if (ret < 0) { |
| 382 | dev_err(&pdev->dev, "DT parsing failed: %d\n", ret); |
| 383 | return ret; |
| 384 | } |
| 385 | } |
| 386 | |
| 387 | if (!pdata->su1_fb && !pdata->su2_fb) { |
| 388 | dev_err(&pdev->dev, "No framebuffer specified\n"); |
| 389 | return -EINVAL; |
| 390 | } |
| 391 | |
Guennadi Liakhovetski | de474b5b | 2013-02-21 16:43:59 -0800 | [diff] [blame] | 392 | /* |
| 393 | * Due to possible hardware damage I chose to block all modes, |
| 394 | * unsupported on my hardware. Anyone, wishing to use any of those modes |
| 395 | * will have to first review the code, then activate and test it. |
| 396 | */ |
| 397 | if (pdata->su1_fb || |
| 398 | pdata->su2_fbprot != AS3711_SU2_GPIO4 || |
| 399 | pdata->su2_feedback != AS3711_SU2_CURR_AUTO) { |
| 400 | dev_warn(&pdev->dev, |
| 401 | "Attention! An untested mode has been chosen!\n" |
| 402 | "Please, review the code, enable, test, and report success:-)\n"); |
| 403 | return -EINVAL; |
| 404 | } |
| 405 | |
| 406 | supply = devm_kzalloc(&pdev->dev, sizeof(*supply), GFP_KERNEL); |
| 407 | if (!supply) |
| 408 | return -ENOMEM; |
| 409 | |
| 410 | supply->as3711 = as3711; |
| 411 | supply->pdata = pdata; |
| 412 | |
| 413 | if (pdata->su1_fb) { |
| 414 | su = &supply->su1; |
| 415 | su->fb_name = pdata->su1_fb; |
| 416 | su->type = AS3711_BL_SU1; |
| 417 | |
| 418 | max_brightness = min(pdata->su1_max_uA, 31); |
| 419 | ret = as3711_bl_register(pdev, max_brightness, su); |
| 420 | if (ret < 0) |
| 421 | return ret; |
| 422 | } |
| 423 | |
| 424 | if (pdata->su2_fb) { |
| 425 | su = &supply->su2; |
| 426 | su->fb_name = pdata->su2_fb; |
| 427 | su->type = AS3711_BL_SU2; |
| 428 | |
| 429 | switch (pdata->su2_fbprot) { |
| 430 | case AS3711_SU2_GPIO2: |
| 431 | case AS3711_SU2_GPIO3: |
| 432 | case AS3711_SU2_GPIO4: |
| 433 | case AS3711_SU2_LX_SD4: |
| 434 | break; |
| 435 | default: |
Jingoo Han | 83dedc0 | 2013-11-12 15:09:10 -0800 | [diff] [blame] | 436 | return -EINVAL; |
Guennadi Liakhovetski | de474b5b | 2013-02-21 16:43:59 -0800 | [diff] [blame] | 437 | } |
| 438 | |
| 439 | switch (pdata->su2_feedback) { |
| 440 | case AS3711_SU2_VOLTAGE: |
| 441 | max_brightness = min(pdata->su2_max_uA, 31); |
| 442 | break; |
| 443 | case AS3711_SU2_CURR1: |
| 444 | case AS3711_SU2_CURR2: |
| 445 | case AS3711_SU2_CURR3: |
| 446 | case AS3711_SU2_CURR_AUTO: |
| 447 | max_brightness = min(pdata->su2_max_uA / 150, 255); |
| 448 | break; |
| 449 | default: |
Jingoo Han | 83dedc0 | 2013-11-12 15:09:10 -0800 | [diff] [blame] | 450 | return -EINVAL; |
Guennadi Liakhovetski | de474b5b | 2013-02-21 16:43:59 -0800 | [diff] [blame] | 451 | } |
| 452 | |
| 453 | ret = as3711_bl_init_su2(supply); |
| 454 | if (ret < 0) |
| 455 | return ret; |
| 456 | |
| 457 | ret = as3711_bl_register(pdev, max_brightness, su); |
| 458 | if (ret < 0) |
Jingoo Han | 83dedc0 | 2013-11-12 15:09:10 -0800 | [diff] [blame] | 459 | return ret; |
Guennadi Liakhovetski | de474b5b | 2013-02-21 16:43:59 -0800 | [diff] [blame] | 460 | } |
| 461 | |
| 462 | platform_set_drvdata(pdev, supply); |
| 463 | |
| 464 | return 0; |
Guennadi Liakhovetski | de474b5b | 2013-02-21 16:43:59 -0800 | [diff] [blame] | 465 | } |
| 466 | |
| 467 | static struct platform_driver as3711_backlight_driver = { |
| 468 | .driver = { |
| 469 | .name = "as3711-backlight", |
| 470 | .owner = THIS_MODULE, |
| 471 | }, |
| 472 | .probe = as3711_backlight_probe, |
Guennadi Liakhovetski | de474b5b | 2013-02-21 16:43:59 -0800 | [diff] [blame] | 473 | }; |
| 474 | |
| 475 | module_platform_driver(as3711_backlight_driver); |
| 476 | |
| 477 | MODULE_DESCRIPTION("Backlight Driver for AS3711 PMICs"); |
| 478 | MODULE_AUTHOR("Guennadi Liakhovetski <g.liakhovetski@gmx.de"); |
| 479 | MODULE_LICENSE("GPL"); |
| 480 | MODULE_ALIAS("platform:as3711-backlight"); |