2 * AS3711 PMIC backlight driver, using DCDC Step Up Converters
4 * Copyright (C) 2012 Renesas Electronics Corporation
5 * Author: Guennadi Liakhovetski, <g.liakhovetski@gmx.de>
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
12 #include <linux/backlight.h>
13 #include <linux/delay.h>
14 #include <linux/device.h>
15 #include <linux/err.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>
29 struct as3711_bl_data {
32 struct device *fb_dev;
33 enum as3711_bl_type type;
35 struct backlight_device *bl;
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;
45 static struct as3711_bl_supply *to_supply(struct as3711_bl_data *su)
49 return container_of(su, struct as3711_bl_supply, su1);
51 return container_of(su, struct as3711_bl_supply, su2);
56 static int as3711_set_brightness_auto_i(struct as3711_bl_data *data,
57 unsigned int brightness)
59 struct as3711_bl_supply *supply = to_supply(data);
60 struct as3711 *as3711 = supply->as3711;
61 const struct as3711_bl_pdata *pdata = supply->pdata;
64 /* Only all equal current values are supported */
65 if (pdata->su2_auto_curr1)
66 ret = regmap_write(as3711->regmap, AS3711_CURR1_VALUE,
68 if (!ret && pdata->su2_auto_curr2)
69 ret = regmap_write(as3711->regmap, AS3711_CURR2_VALUE,
71 if (!ret && pdata->su2_auto_curr3)
72 ret = regmap_write(as3711->regmap, AS3711_CURR3_VALUE,
78 static int as3711_set_brightness_v(struct as3711 *as3711,
79 unsigned int brightness,
85 return regmap_update_bits(as3711->regmap, reg, 0xf0,
89 static int as3711_bl_su2_reset(struct as3711_bl_supply *supply)
91 struct as3711 *as3711 = supply->as3711;
92 int ret = regmap_update_bits(as3711->regmap, AS3711_STEPUP_CONTROL_5,
93 3, supply->pdata->su2_fbprot);
95 ret = regmap_update_bits(as3711->regmap,
96 AS3711_STEPUP_CONTROL_2, 1, 0);
98 ret = regmap_update_bits(as3711->regmap,
99 AS3711_STEPUP_CONTROL_2, 1, 1);
104 * Someone with less fragile or less expensive hardware could try to simplify
105 * the brightness adjustment procedure.
107 static int as3711_bl_update_status(struct backlight_device *bl)
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;
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);
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))
124 if (data->type == AS3711_BL_SU1) {
125 ret = as3711_set_brightness_v(as3711, brightness,
126 AS3711_STEPUP_CONTROL_1);
128 const struct as3711_bl_pdata *pdata = supply->pdata;
130 switch (pdata->su2_feedback) {
131 case AS3711_SU2_VOLTAGE:
132 ret = as3711_set_brightness_v(as3711, brightness,
133 AS3711_STEPUP_CONTROL_2);
135 case AS3711_SU2_CURR_AUTO:
136 ret = as3711_set_brightness_auto_i(data, brightness / 4);
140 ret = as3711_bl_su2_reset(supply);
144 ret = as3711_set_brightness_auto_i(data, brightness);
146 ret = regmap_update_bits(as3711->regmap,
147 AS3711_STEPUP_CONTROL_2, 1, 0);
150 /* Manual one current feedback pin below */
151 case AS3711_SU2_CURR1:
152 ret = regmap_write(as3711->regmap, AS3711_CURR1_VALUE,
155 case AS3711_SU2_CURR2:
156 ret = regmap_write(as3711->regmap, AS3711_CURR2_VALUE,
159 case AS3711_SU2_CURR3:
160 ret = regmap_write(as3711->regmap, AS3711_CURR3_VALUE,
168 data->brightness = brightness;
173 static int as3711_bl_get_brightness(struct backlight_device *bl)
175 struct as3711_bl_data *data = bl_get_data(bl);
177 return data->brightness;
180 static const struct backlight_ops as3711_bl_ops = {
181 .update_status = as3711_bl_update_status,
182 .get_brightness = as3711_bl_get_brightness,
185 static int as3711_bl_init_su2(struct as3711_bl_supply *supply)
187 struct as3711 *as3711 = supply->as3711;
188 const struct as3711_bl_pdata *pdata = supply->pdata;
192 dev_dbg(as3711->dev, "%s(): use %u\n", __func__, pdata->su2_feedback);
195 ret = regmap_write(as3711->regmap, AS3711_STEPUP_CONTROL_2, 0);
199 switch (pdata->su2_feedback) {
200 case AS3711_SU2_VOLTAGE:
201 ret = regmap_update_bits(as3711->regmap, AS3711_STEPUP_CONTROL_4, 3, 0);
203 case AS3711_SU2_CURR1:
205 ret = regmap_update_bits(as3711->regmap, AS3711_STEPUP_CONTROL_4, 3, 1);
207 case AS3711_SU2_CURR2:
209 ret = regmap_update_bits(as3711->regmap, AS3711_STEPUP_CONTROL_4, 3, 2);
211 case AS3711_SU2_CURR3:
213 ret = regmap_update_bits(as3711->regmap, AS3711_STEPUP_CONTROL_4, 3, 3);
215 case AS3711_SU2_CURR_AUTO:
216 if (pdata->su2_auto_curr1)
218 if (pdata->su2_auto_curr2)
220 if (pdata->su2_auto_curr3)
229 ret = regmap_write(as3711->regmap, AS3711_CURR_CONTROL, ctl);
234 static int as3711_bl_register(struct platform_device *pdev,
235 unsigned int max_brightness, struct as3711_bl_data *su)
237 struct backlight_properties props = {.type = BACKLIGHT_RAW,};
238 struct backlight_device *bl;
240 /* max tuning I = 31uA for voltage- and 38250uA for current-feedback */
241 props.max_brightness = max_brightness;
243 bl = backlight_device_register(su->type == AS3711_BL_SU1 ?
244 "as3711-su1" : "as3711-su2",
246 &as3711_bl_ops, &props);
248 dev_err(&pdev->dev, "failed to register backlight\n");
252 bl->props.brightness = props.max_brightness;
254 backlight_update_status(bl);
261 static int as3711_backlight_probe(struct platform_device *pdev)
263 struct as3711_bl_pdata *pdata = dev_get_platdata(&pdev->dev);
264 struct as3711 *as3711 = dev_get_drvdata(pdev->dev.parent);
265 struct as3711_bl_supply *supply;
266 struct as3711_bl_data *su;
267 unsigned int max_brightness;
270 if (!pdata || (!pdata->su1_fb && !pdata->su2_fb)) {
271 dev_err(&pdev->dev, "No platform data, exiting...\n");
276 * Due to possible hardware damage I chose to block all modes,
277 * unsupported on my hardware. Anyone, wishing to use any of those modes
278 * will have to first review the code, then activate and test it.
281 pdata->su2_fbprot != AS3711_SU2_GPIO4 ||
282 pdata->su2_feedback != AS3711_SU2_CURR_AUTO) {
284 "Attention! An untested mode has been chosen!\n"
285 "Please, review the code, enable, test, and report success:-)\n");
289 supply = devm_kzalloc(&pdev->dev, sizeof(*supply), GFP_KERNEL);
293 supply->as3711 = as3711;
294 supply->pdata = pdata;
298 su->fb_name = pdata->su1_fb;
299 su->type = AS3711_BL_SU1;
301 max_brightness = min(pdata->su1_max_uA, 31);
302 ret = as3711_bl_register(pdev, max_brightness, su);
309 su->fb_name = pdata->su2_fb;
310 su->type = AS3711_BL_SU2;
312 switch (pdata->su2_fbprot) {
313 case AS3711_SU2_GPIO2:
314 case AS3711_SU2_GPIO3:
315 case AS3711_SU2_GPIO4:
316 case AS3711_SU2_LX_SD4:
323 switch (pdata->su2_feedback) {
324 case AS3711_SU2_VOLTAGE:
325 max_brightness = min(pdata->su2_max_uA, 31);
327 case AS3711_SU2_CURR1:
328 case AS3711_SU2_CURR2:
329 case AS3711_SU2_CURR3:
330 case AS3711_SU2_CURR_AUTO:
331 max_brightness = min(pdata->su2_max_uA / 150, 255);
338 ret = as3711_bl_init_su2(supply);
342 ret = as3711_bl_register(pdev, max_brightness, su);
347 platform_set_drvdata(pdev, supply);
352 backlight_device_unregister(supply->su1.bl);
356 static int as3711_backlight_remove(struct platform_device *pdev)
358 struct as3711_bl_supply *supply = platform_get_drvdata(pdev);
360 backlight_device_unregister(supply->su1.bl);
361 backlight_device_unregister(supply->su2.bl);
366 static struct platform_driver as3711_backlight_driver = {
368 .name = "as3711-backlight",
369 .owner = THIS_MODULE,
371 .probe = as3711_backlight_probe,
372 .remove = as3711_backlight_remove,
375 module_platform_driver(as3711_backlight_driver);
377 MODULE_DESCRIPTION("Backlight Driver for AS3711 PMICs");
378 MODULE_AUTHOR("Guennadi Liakhovetski <g.liakhovetski@gmx.de");
379 MODULE_LICENSE("GPL");
380 MODULE_ALIAS("platform:as3711-backlight");