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Tom Rini83d290c2018-05-06 17:58:06 -04001// SPDX-License-Identifier: GPL-2.0+
Simon Glass65fba592016-01-21 19:44:57 -07002/*
3 * Copyright (c) 2016 Google, Inc
4 * Written by Simon Glass <sjg@chromium.org>
Simon Glass65fba592016-01-21 19:44:57 -07005 */
6
Simon Glassa4f737a2018-10-01 12:22:41 -06007#define LOG_CATEGORY UCLASS_PANEL_BACKLIGHT
8
Simon Glass65fba592016-01-21 19:44:57 -07009#include <common.h>
10#include <dm.h>
11#include <backlight.h>
12#include <pwm.h>
13#include <asm/gpio.h>
14#include <power/regulator.h>
15
Simon Glassa4f737a2018-10-01 12:22:41 -060016/**
17 * Private information for the PWM backlight
18 *
19 * If @num_levels is 0 then the levels are simple values with the backlight
20 * value going between the minimum (default 0) and the maximum (default 255).
21 * Otherwise the levels are an index into @levels (0..n-1).
22 *
23 * @reg: Regulator to enable to turn the backlight on (NULL if none)
24 * @enable, GPIO to set to enable the backlight (can be missing)
25 * @pwm: PWM to use to change the backlight brightness
26 * @channel: PWM channel to use
27 * @period_ns: Period of the backlight in nanoseconds
28 * @levels: Levels for the backlight, or NULL if not using indexed levels
29 * @num_levels: Number of levels
30 * @cur_level: Current level for the backlight (index or value)
31 * @default_level: Default level for the backlight (index or value)
32 * @min_level: Minimum level of the backlight (full off)
33 * @min_level: Maximum level of the backlight (full on)
34 * @enabled: true if backlight is enabled
35 */
Simon Glass65fba592016-01-21 19:44:57 -070036struct pwm_backlight_priv {
37 struct udevice *reg;
38 struct gpio_desc enable;
39 struct udevice *pwm;
40 uint channel;
41 uint period_ns;
Stefan Mavrodiev57e77752019-04-12 08:56:27 +030042 /*
43 * the polarity of one PWM
44 * 0: normal polarity
45 * 1: inverted polarity
46 */
47 bool polarity;
Simon Glassa4f737a2018-10-01 12:22:41 -060048 u32 *levels;
49 int num_levels;
Simon Glass65fba592016-01-21 19:44:57 -070050 uint default_level;
Simon Glassa4f737a2018-10-01 12:22:41 -060051 int cur_level;
Simon Glass65fba592016-01-21 19:44:57 -070052 uint min_level;
53 uint max_level;
Simon Glassa4f737a2018-10-01 12:22:41 -060054 bool enabled;
Simon Glass65fba592016-01-21 19:44:57 -070055};
56
Simon Glassa4f737a2018-10-01 12:22:41 -060057static int set_pwm(struct pwm_backlight_priv *priv)
58{
59 uint duty_cycle;
60 int ret;
61
62 duty_cycle = priv->period_ns * (priv->cur_level - priv->min_level) /
63 (priv->max_level - priv->min_level + 1);
64 ret = pwm_set_config(priv->pwm, priv->channel, priv->period_ns,
65 duty_cycle);
Stefan Mavrodiev57e77752019-04-12 08:56:27 +030066 if (ret)
67 return log_ret(ret);
Simon Glassa4f737a2018-10-01 12:22:41 -060068
Stefan Mavrodiev57e77752019-04-12 08:56:27 +030069 ret = pwm_set_invert(priv->pwm, priv->channel, priv->polarity);
Simon Glassa4f737a2018-10-01 12:22:41 -060070 return log_ret(ret);
71}
72
73static int enable_sequence(struct udevice *dev, int seq)
74{
75 struct pwm_backlight_priv *priv = dev_get_priv(dev);
76 int ret;
77
78 switch (seq) {
79 case 0:
80 if (priv->reg) {
81 __maybe_unused struct dm_regulator_uclass_platdata
82 *plat;
83
84 plat = dev_get_uclass_platdata(priv->reg);
85 log_debug("Enable '%s', regulator '%s'/'%s'\n",
86 dev->name, priv->reg->name, plat->name);
87 ret = regulator_set_enable(priv->reg, true);
88 if (ret) {
89 log_debug("Cannot enable regulator for PWM '%s'\n",
Simon Glass4a978e82018-11-23 21:29:39 -070090 dev->name);
Simon Glassa4f737a2018-10-01 12:22:41 -060091 return log_ret(ret);
92 }
93 mdelay(120);
94 }
95 break;
96 case 1:
97 mdelay(10);
98 dm_gpio_set_value(&priv->enable, 1);
99 break;
100 }
101
102 return 0;
103}
104
Simon Glass65fba592016-01-21 19:44:57 -0700105static int pwm_backlight_enable(struct udevice *dev)
106{
107 struct pwm_backlight_priv *priv = dev_get_priv(dev);
Simon Glass65fba592016-01-21 19:44:57 -0700108 int ret;
109
Simon Glassa4f737a2018-10-01 12:22:41 -0600110 ret = enable_sequence(dev, 0);
Simon Glass65fba592016-01-21 19:44:57 -0700111 if (ret)
Simon Glassa4f737a2018-10-01 12:22:41 -0600112 return log_ret(ret);
113 ret = set_pwm(priv);
114 if (ret)
115 return log_ret(ret);
Simon Glass65fba592016-01-21 19:44:57 -0700116 ret = pwm_set_enable(priv->pwm, priv->channel, true);
117 if (ret)
Simon Glassa4f737a2018-10-01 12:22:41 -0600118 return log_ret(ret);
119 ret = enable_sequence(dev, 1);
120 if (ret)
121 return log_ret(ret);
122 priv->enabled = true;
123
124 return 0;
125}
126
127static int pwm_backlight_set_brightness(struct udevice *dev, int percent)
128{
129 struct pwm_backlight_priv *priv = dev_get_priv(dev);
130 bool disable = false;
131 int level;
132 int ret;
133
134 if (!priv->enabled) {
135 ret = enable_sequence(dev, 0);
136 if (ret)
137 return log_ret(ret);
138 }
139 if (percent == BACKLIGHT_OFF) {
140 disable = true;
141 percent = 0;
142 }
143 if (percent == BACKLIGHT_DEFAULT) {
144 level = priv->default_level;
145 } else {
146 if (priv->levels) {
147 level = priv->levels[percent * (priv->num_levels - 1)
148 / 100];
149 } else {
150 level = priv->min_level +
151 (priv->max_level - priv->min_level) *
152 percent / 100;
153 }
154 }
155 priv->cur_level = level;
156
157 ret = set_pwm(priv);
158 if (ret)
159 return log_ret(ret);
160 if (!priv->enabled) {
161 ret = enable_sequence(dev, 1);
162 if (ret)
163 return log_ret(ret);
164 priv->enabled = true;
165 }
166 if (disable) {
167 dm_gpio_set_value(&priv->enable, 0);
168 if (priv->reg) {
169 ret = regulator_set_enable(priv->reg, false);
170 if (ret)
171 return log_ret(ret);
172 }
173 priv->enabled = false;
174 }
Simon Glass65fba592016-01-21 19:44:57 -0700175
176 return 0;
177}
178
179static int pwm_backlight_ofdata_to_platdata(struct udevice *dev)
180{
181 struct pwm_backlight_priv *priv = dev_get_priv(dev);
Simon Glass7cf208d2017-06-12 06:21:37 -0600182 struct ofnode_phandle_args args;
Simon Glass65fba592016-01-21 19:44:57 -0700183 int index, ret, count, len;
184 const u32 *cell;
185
Simon Glassa4f737a2018-10-01 12:22:41 -0600186 log_debug("start\n");
Simon Glass65fba592016-01-21 19:44:57 -0700187 ret = uclass_get_device_by_phandle(UCLASS_REGULATOR, dev,
188 "power-supply", &priv->reg);
Kever Yang19f124d2018-02-09 10:45:12 +0800189 if (ret)
Simon Glassa4f737a2018-10-01 12:22:41 -0600190 log_debug("Cannot get power supply: ret=%d\n", ret);
Simon Glass65fba592016-01-21 19:44:57 -0700191 ret = gpio_request_by_name(dev, "enable-gpios", 0, &priv->enable,
192 GPIOD_IS_OUT);
193 if (ret) {
Simon Glassa4f737a2018-10-01 12:22:41 -0600194 log_debug("Warning: cannot get enable GPIO: ret=%d\n", ret);
Simon Glass65fba592016-01-21 19:44:57 -0700195 if (ret != -ENOENT)
Simon Glassa4f737a2018-10-01 12:22:41 -0600196 return log_ret(ret);
Simon Glass65fba592016-01-21 19:44:57 -0700197 }
Simon Glass7cf208d2017-06-12 06:21:37 -0600198 ret = dev_read_phandle_with_args(dev, "pwms", "#pwm-cells", 0, 0,
199 &args);
Simon Glass65fba592016-01-21 19:44:57 -0700200 if (ret) {
Simon Glassa4f737a2018-10-01 12:22:41 -0600201 log_debug("Cannot get PWM phandle: ret=%d\n", ret);
202 return log_ret(ret);
Simon Glass65fba592016-01-21 19:44:57 -0700203 }
204
Simon Glass7cf208d2017-06-12 06:21:37 -0600205 ret = uclass_get_device_by_ofnode(UCLASS_PWM, args.node, &priv->pwm);
Simon Glass65fba592016-01-21 19:44:57 -0700206 if (ret) {
Simon Glassa4f737a2018-10-01 12:22:41 -0600207 log_debug("Cannot get PWM: ret=%d\n", ret);
208 return log_ret(ret);
Simon Glass65fba592016-01-21 19:44:57 -0700209 }
Simon Glassa4f737a2018-10-01 12:22:41 -0600210 if (args.args_count < 2)
211 return log_msg_ret("Not enough arguments to pwm\n", -EINVAL);
Simon Glass65fba592016-01-21 19:44:57 -0700212 priv->channel = args.args[0];
213 priv->period_ns = args.args[1];
Stefan Mavrodiev57e77752019-04-12 08:56:27 +0300214 if (args.args_count > 2)
215 priv->polarity = args.args[2];
Simon Glass65fba592016-01-21 19:44:57 -0700216
Simon Glass7cf208d2017-06-12 06:21:37 -0600217 index = dev_read_u32_default(dev, "default-brightness-level", 255);
218 cell = dev_read_prop(dev, "brightness-levels", &len);
Simon Glass65fba592016-01-21 19:44:57 -0700219 count = len / sizeof(u32);
220 if (cell && count > index) {
Simon Glassa4f737a2018-10-01 12:22:41 -0600221 priv->levels = malloc(len);
222 if (!priv->levels)
223 return log_ret(-ENOMEM);
224 dev_read_u32_array(dev, "brightness-levels", priv->levels,
225 count);
226 priv->num_levels = count;
227 priv->default_level = priv->levels[index];
228 priv->max_level = priv->levels[count - 1];
Simon Glass65fba592016-01-21 19:44:57 -0700229 } else {
230 priv->default_level = index;
231 priv->max_level = 255;
232 }
Simon Glassa4f737a2018-10-01 12:22:41 -0600233 priv->cur_level = priv->default_level;
234 log_debug("done\n");
Simon Glass65fba592016-01-21 19:44:57 -0700235
236
237 return 0;
238}
239
240static int pwm_backlight_probe(struct udevice *dev)
241{
242 return 0;
243}
244
245static const struct backlight_ops pwm_backlight_ops = {
Simon Glassa4f737a2018-10-01 12:22:41 -0600246 .enable = pwm_backlight_enable,
247 .set_brightness = pwm_backlight_set_brightness,
Simon Glass65fba592016-01-21 19:44:57 -0700248};
249
250static const struct udevice_id pwm_backlight_ids[] = {
251 { .compatible = "pwm-backlight" },
252 { }
253};
254
255U_BOOT_DRIVER(pwm_backlight) = {
256 .name = "pwm_backlight",
257 .id = UCLASS_PANEL_BACKLIGHT,
258 .of_match = pwm_backlight_ids,
259 .ops = &pwm_backlight_ops,
260 .ofdata_to_platdata = pwm_backlight_ofdata_to_platdata,
261 .probe = pwm_backlight_probe,
262 .priv_auto_alloc_size = sizeof(struct pwm_backlight_priv),
263};