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8#include <common.h>
9#include <dm.h>
10#include <backlight.h>
11#include <pwm.h>
12#include <asm/gpio.h>
13#include <power/regulator.h>
14
15DECLARE_GLOBAL_DATA_PTR;
16
17struct pwm_backlight_priv {
18 struct udevice *reg;
19 struct gpio_desc enable;
20 struct udevice *pwm;
21 uint channel;
22 uint period_ns;
23 uint default_level;
24 uint min_level;
25 uint max_level;
26};
27
28static int pwm_backlight_enable(struct udevice *dev)
29{
30 struct pwm_backlight_priv *priv = dev_get_priv(dev);
31 uint duty_cycle;
32 int ret;
33
34 debug("%s: Enable '%s', regulator '%s'\n", __func__, dev->name,
35 priv->reg->name);
36 ret = regulator_set_enable(priv->reg, true);
37 if (ret) {
38 debug("%s: Cannot enable regulator for PWM '%s'\n", __func__,
39 dev->name);
40 return ret;
41 }
42 mdelay(120);
43
44 duty_cycle = priv->period_ns * (priv->default_level - priv->min_level) /
45 (priv->max_level - priv->min_level + 1);
46 ret = pwm_set_config(priv->pwm, priv->channel, priv->period_ns,
47 duty_cycle);
48 if (ret)
49 return ret;
50 ret = pwm_set_enable(priv->pwm, priv->channel, true);
51 if (ret)
52 return ret;
53 mdelay(10);
54 dm_gpio_set_value(&priv->enable, 1);
55
56 return 0;
57}
58
59static int pwm_backlight_ofdata_to_platdata(struct udevice *dev)
60{
61 struct pwm_backlight_priv *priv = dev_get_priv(dev);
62 struct fdtdec_phandle_args args;
63 const void *blob = gd->fdt_blob;
64 int node = dev->of_offset;
65 int index, ret, count, len;
66 const u32 *cell;
67
68 ret = uclass_get_device_by_phandle(UCLASS_REGULATOR, dev,
69 "power-supply", &priv->reg);
70 if (ret) {
71 debug("%s: Cannot get power supply: ret=%d\n", __func__, ret);
72 return ret;
73 }
74 ret = gpio_request_by_name(dev, "enable-gpios", 0, &priv->enable,
75 GPIOD_IS_OUT);
76 if (ret) {
77 debug("%s: Warning: cannot get enable GPIO: ret=%d\n",
78 __func__, ret);
79 if (ret != -ENOENT)
80 return ret;
81 }
82 ret = fdtdec_parse_phandle_with_args(blob, node, "pwms", "#pwm-cells",
83 0, 0, &args);
84 if (ret) {
85 debug("%s: Cannot get PWM phandle: ret=%d\n", __func__, ret);
86 return ret;
87 }
88
89 ret = uclass_get_device_by_of_offset(UCLASS_PWM, args.node, &priv->pwm);
90 if (ret) {
91 debug("%s: Cannot get PWM: ret=%d\n", __func__, ret);
92 return ret;
93 }
94 priv->channel = args.args[0];
95 priv->period_ns = args.args[1];
96
97 index = fdtdec_get_int(blob, node, "default-brightness-level", 255);
98 cell = fdt_getprop(blob, node, "brightness-levels", &len);
99 count = len / sizeof(u32);
100 if (cell && count > index) {
101 priv->default_level = fdt32_to_cpu(cell[index]);
102 priv->max_level = fdt32_to_cpu(cell[count - 1]);
103 } else {
104 priv->default_level = index;
105 priv->max_level = 255;
106 }
107
108
109 return 0;
110}
111
112static int pwm_backlight_probe(struct udevice *dev)
113{
114 return 0;
115}
116
117static const struct backlight_ops pwm_backlight_ops = {
118 .enable = pwm_backlight_enable,
119};
120
121static const struct udevice_id pwm_backlight_ids[] = {
122 { .compatible = "pwm-backlight" },
123 { }
124};
125
126U_BOOT_DRIVER(pwm_backlight) = {
127 .name = "pwm_backlight",
128 .id = UCLASS_PANEL_BACKLIGHT,
129 .of_match = pwm_backlight_ids,
130 .ops = &pwm_backlight_ops,
131 .ofdata_to_platdata = pwm_backlight_ofdata_to_platdata,
132 .probe = pwm_backlight_probe,
133 .priv_auto_alloc_size = sizeof(struct pwm_backlight_priv),
134};
135
