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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
41c42ff5 LF |
2 | /* |
3 | * linux/drivers/leds-pwm.c | |
4 | * | |
5 | * simple PWM based LED control | |
6 | * | |
7 | * Copyright 2009 Luotao Fu @ Pengutronix (l.fu@pengutronix.de) | |
8 | * | |
9 | * based on leds-gpio.c by Raphael Assenat <raph@8d.com> | |
41c42ff5 LF |
10 | */ |
11 | ||
12 | #include <linux/module.h> | |
13 | #include <linux/kernel.h> | |
41c42ff5 | 14 | #include <linux/platform_device.h> |
08541cbc | 15 | #include <linux/of_platform.h> |
41c42ff5 LF |
16 | #include <linux/leds.h> |
17 | #include <linux/err.h> | |
18 | #include <linux/pwm.h> | |
19 | #include <linux/leds_pwm.h> | |
5a0e3ad6 | 20 | #include <linux/slab.h> |
41c42ff5 LF |
21 | |
22 | struct led_pwm_data { | |
23 | struct led_classdev cdev; | |
24 | struct pwm_device *pwm; | |
dcba9105 | 25 | unsigned int active_low; |
41c42ff5 | 26 | unsigned int period; |
c971ff18 | 27 | int duty; |
41c42ff5 LF |
28 | }; |
29 | ||
0f86815a PU |
30 | struct led_pwm_priv { |
31 | int num_leds; | |
32 | struct led_pwm_data leds[0]; | |
33 | }; | |
34 | ||
c971ff18 FV |
35 | static void __led_pwm_set(struct led_pwm_data *led_dat) |
36 | { | |
37 | int new_duty = led_dat->duty; | |
38 | ||
39 | pwm_config(led_dat->pwm, new_duty, led_dat->period); | |
40 | ||
41 | if (new_duty == 0) | |
42 | pwm_disable(led_dat->pwm); | |
43 | else | |
44 | pwm_enable(led_dat->pwm); | |
45 | } | |
46 | ||
247bde13 TR |
47 | static int led_pwm_set(struct led_classdev *led_cdev, |
48 | enum led_brightness brightness) | |
41c42ff5 LF |
49 | { |
50 | struct led_pwm_data *led_dat = | |
51 | container_of(led_cdev, struct led_pwm_data, cdev); | |
e4590620 | 52 | unsigned int max = led_dat->cdev.max_brightness; |
fc1aee03 | 53 | unsigned long long duty = led_dat->period; |
41c42ff5 | 54 | |
fc1aee03 XL |
55 | duty *= brightness; |
56 | do_div(duty, max); | |
d19a8a70 RK |
57 | |
58 | if (led_dat->active_low) | |
59 | duty = led_dat->period - duty; | |
60 | ||
fc1aee03 | 61 | led_dat->duty = duty; |
c971ff18 | 62 | |
9aa07625 | 63 | __led_pwm_set(led_dat); |
9aa07625 | 64 | |
9aa07625 | 65 | return 0; |
41c42ff5 LF |
66 | } |
67 | ||
0f86815a PU |
68 | static inline size_t sizeof_pwm_leds_priv(int num_leds) |
69 | { | |
70 | return sizeof(struct led_pwm_priv) + | |
71 | (sizeof(struct led_pwm_data) * num_leds); | |
72 | } | |
73 | ||
5f7b03dc | 74 | static int led_pwm_add(struct device *dev, struct led_pwm_priv *priv, |
3f467ebe | 75 | struct led_pwm *led, struct fwnode_handle *fwnode) |
41c42ff5 | 76 | { |
5f7b03dc | 77 | struct led_pwm_data *led_data = &priv->leds[priv->num_leds]; |
1b50673d | 78 | struct pwm_args pargs; |
aa1a6d6d | 79 | int ret; |
41c42ff5 | 80 | |
5f7b03dc | 81 | led_data->active_low = led->active_low; |
5f7b03dc RK |
82 | led_data->cdev.name = led->name; |
83 | led_data->cdev.default_trigger = led->default_trigger; | |
5f7b03dc RK |
84 | led_data->cdev.brightness = LED_OFF; |
85 | led_data->cdev.max_brightness = led->max_brightness; | |
86 | led_data->cdev.flags = LED_CORE_SUSPENDRESUME; | |
41c42ff5 | 87 | |
3f467ebe NV |
88 | if (fwnode) |
89 | led_data->pwm = devm_fwnode_pwm_get(dev, fwnode, NULL); | |
b795e6d9 RK |
90 | else |
91 | led_data->pwm = devm_pwm_get(dev, led->name); | |
5f7b03dc RK |
92 | if (IS_ERR(led_data->pwm)) { |
93 | ret = PTR_ERR(led_data->pwm); | |
9aec3037 JB |
94 | if (ret != -EPROBE_DEFER) |
95 | dev_err(dev, "unable to request PWM for %s: %d\n", | |
96 | led->name, ret); | |
5f7b03dc RK |
97 | return ret; |
98 | } | |
08541cbc | 99 | |
247bde13 | 100 | led_data->cdev.brightness_set_blocking = led_pwm_set; |
41c42ff5 | 101 | |
1b50673d BB |
102 | /* |
103 | * FIXME: pwm_apply_args() should be removed when switching to the | |
104 | * atomic PWM API. | |
105 | */ | |
106 | pwm_apply_args(led_data->pwm); | |
107 | ||
108 | pwm_get_args(led_data->pwm, &pargs); | |
109 | ||
110 | led_data->period = pargs.period; | |
7c574cf6 LT |
111 | if (!led_data->period && (led->pwm_period_ns > 0)) |
112 | led_data->period = led->pwm_period_ns; | |
41c42ff5 | 113 | |
3f467ebe NV |
114 | ret = devm_of_led_classdev_register(dev, to_of_node(fwnode), |
115 | &led_data->cdev); | |
5f7b03dc RK |
116 | if (ret == 0) { |
117 | priv->num_leds++; | |
f1670336 | 118 | led_pwm_set(&led_data->cdev, led_data->cdev.brightness); |
5f7b03dc RK |
119 | } else { |
120 | dev_err(dev, "failed to register PWM led for %s: %d\n", | |
121 | led->name, ret); | |
122 | } | |
123 | ||
124 | return ret; | |
125 | } | |
c971ff18 | 126 | |
3f467ebe | 127 | static int led_pwm_create_fwnode(struct device *dev, struct led_pwm_priv *priv) |
41c42ff5 | 128 | { |
3f467ebe | 129 | struct fwnode_handle *fwnode; |
b795e6d9 RK |
130 | struct led_pwm led; |
131 | int ret = 0; | |
41c42ff5 | 132 | |
b795e6d9 | 133 | memset(&led, 0, sizeof(led)); |
08541cbc | 134 | |
3f467ebe NV |
135 | device_for_each_child_node(dev, fwnode) { |
136 | ret = fwnode_property_read_string(fwnode, "label", &led.name); | |
137 | if (ret && is_of_node(fwnode)) | |
138 | led.name = to_of_node(fwnode)->name; | |
08541cbc | 139 | |
3f467ebe NV |
140 | if (!led.name) { |
141 | fwnode_handle_put(fwnode); | |
142 | return -EINVAL; | |
143 | } | |
144 | ||
145 | fwnode_property_read_string(fwnode, "linux,default-trigger", | |
146 | &led.default_trigger); | |
147 | ||
148 | led.active_low = fwnode_property_read_bool(fwnode, | |
149 | "active-low"); | |
150 | fwnode_property_read_u32(fwnode, "max-brightness", | |
151 | &led.max_brightness); | |
c971ff18 | 152 | |
3f467ebe | 153 | ret = led_pwm_add(dev, priv, &led, fwnode); |
b795e6d9 | 154 | if (ret) { |
3f467ebe | 155 | fwnode_handle_put(fwnode); |
b795e6d9 | 156 | break; |
08541cbc | 157 | } |
08541cbc PU |
158 | } |
159 | ||
aa1a6d6d | 160 | return ret; |
08541cbc PU |
161 | } |
162 | ||
163 | static int led_pwm_probe(struct platform_device *pdev) | |
164 | { | |
87aae1ea | 165 | struct led_pwm_platform_data *pdata = dev_get_platdata(&pdev->dev); |
08541cbc | 166 | struct led_pwm_priv *priv; |
aa1a6d6d PU |
167 | int count, i; |
168 | int ret = 0; | |
169 | ||
170 | if (pdata) | |
171 | count = pdata->num_leds; | |
172 | else | |
3f467ebe | 173 | count = device_get_child_node_count(&pdev->dev); |
aa1a6d6d PU |
174 | |
175 | if (!count) | |
176 | return -EINVAL; | |
08541cbc | 177 | |
aa1a6d6d PU |
178 | priv = devm_kzalloc(&pdev->dev, sizeof_pwm_leds_priv(count), |
179 | GFP_KERNEL); | |
180 | if (!priv) | |
181 | return -ENOMEM; | |
08541cbc | 182 | |
aa1a6d6d PU |
183 | if (pdata) { |
184 | for (i = 0; i < count; i++) { | |
b795e6d9 RK |
185 | ret = led_pwm_add(&pdev->dev, priv, &pdata->leds[i], |
186 | NULL); | |
5f7b03dc RK |
187 | if (ret) |
188 | break; | |
08541cbc | 189 | } |
08541cbc | 190 | } else { |
3f467ebe | 191 | ret = led_pwm_create_fwnode(&pdev->dev, priv); |
5f7b03dc RK |
192 | } |
193 | ||
e5a0436d | 194 | if (ret) |
5f7b03dc | 195 | return ret; |
41c42ff5 | 196 | |
0f86815a | 197 | platform_set_drvdata(pdev, priv); |
41c42ff5 LF |
198 | |
199 | return 0; | |
41c42ff5 LF |
200 | } |
201 | ||
08541cbc PU |
202 | static const struct of_device_id of_pwm_leds_match[] = { |
203 | { .compatible = "pwm-leds", }, | |
204 | {}, | |
205 | }; | |
206 | MODULE_DEVICE_TABLE(of, of_pwm_leds_match); | |
207 | ||
41c42ff5 LF |
208 | static struct platform_driver led_pwm_driver = { |
209 | .probe = led_pwm_probe, | |
41c42ff5 LF |
210 | .driver = { |
211 | .name = "leds_pwm", | |
1e08f72d | 212 | .of_match_table = of_pwm_leds_match, |
41c42ff5 LF |
213 | }, |
214 | }; | |
215 | ||
892a8843 | 216 | module_platform_driver(led_pwm_driver); |
41c42ff5 LF |
217 | |
218 | MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>"); | |
49651c6c UKK |
219 | MODULE_DESCRIPTION("generic PWM LED driver"); |
220 | MODULE_LICENSE("GPL v2"); | |
41c42ff5 | 221 | MODULE_ALIAS("platform:leds-pwm"); |