1 /*
2 * Copyright (c) 2020 Seagate Technology LLC
3 *
4 * SPDX-License-Identifier: Apache-2.0
5 */
6
7 #define DT_DRV_COMPAT pwm_leds
8
9 /**
10 * @file
11 * @brief PWM driven LEDs
12 */
13
14 #include <zephyr/drivers/led.h>
15 #include <zephyr/drivers/pwm.h>
16 #include <zephyr/device.h>
17 #include <zephyr/pm/device.h>
18 #include <zephyr/kernel.h>
19 #include <zephyr/sys/math_extras.h>
20
21 #include <zephyr/logging/log.h>
22 LOG_MODULE_REGISTER(led_pwm, CONFIG_LED_LOG_LEVEL);
23
24 struct led_pwm_config {
25 int num_leds;
26 const struct pwm_dt_spec *led;
27 };
28
led_pwm_blink(const struct device * dev,uint32_t led,uint32_t delay_on,uint32_t delay_off)29 static int led_pwm_blink(const struct device *dev, uint32_t led,
30 uint32_t delay_on, uint32_t delay_off)
31 {
32 const struct led_pwm_config *config = dev->config;
33 const struct pwm_dt_spec *dt_led;
34 uint32_t period_usec, pulse_usec;
35
36 if (led >= config->num_leds) {
37 return -EINVAL;
38 }
39
40 /*
41 * Convert delays (in ms) into PWM period and pulse (in us) and check
42 * for overflows.
43 */
44 if (u32_add_overflow(delay_on, delay_off, &period_usec) ||
45 u32_mul_overflow(period_usec, 1000, &period_usec) ||
46 u32_mul_overflow(delay_on, 1000, &pulse_usec)) {
47 return -EINVAL;
48 }
49
50 dt_led = &config->led[led];
51
52 return pwm_set_dt(dt_led, PWM_USEC(period_usec), PWM_USEC(pulse_usec));
53 }
54
led_pwm_set_brightness(const struct device * dev,uint32_t led,uint8_t value)55 static int led_pwm_set_brightness(const struct device *dev,
56 uint32_t led, uint8_t value)
57 {
58 const struct led_pwm_config *config = dev->config;
59 const struct pwm_dt_spec *dt_led;
60
61 if (led >= config->num_leds || value > 100) {
62 return -EINVAL;
63 }
64
65 dt_led = &config->led[led];
66
67 return pwm_set_pulse_dt(&config->led[led],
68 (uint32_t) ((uint64_t) dt_led->period * value / 100));
69 }
70
led_pwm_on(const struct device * dev,uint32_t led)71 static int led_pwm_on(const struct device *dev, uint32_t led)
72 {
73 return led_pwm_set_brightness(dev, led, 100);
74 }
75
led_pwm_off(const struct device * dev,uint32_t led)76 static int led_pwm_off(const struct device *dev, uint32_t led)
77 {
78 return led_pwm_set_brightness(dev, led, 0);
79 }
80
led_pwm_init(const struct device * dev)81 static int led_pwm_init(const struct device *dev)
82 {
83 const struct led_pwm_config *config = dev->config;
84 int i;
85
86 if (!config->num_leds) {
87 LOG_ERR("%s: no LEDs found (DT child nodes missing)",
88 dev->name);
89 return -ENODEV;
90 }
91
92 for (i = 0; i < config->num_leds; i++) {
93 const struct pwm_dt_spec *led = &config->led[i];
94
95 if (!device_is_ready(led->dev)) {
96 LOG_ERR("%s: pwm device not ready", led->dev->name);
97 return -ENODEV;
98 }
99 }
100
101 return 0;
102 }
103
104 #ifdef CONFIG_PM_DEVICE
led_pwm_pm_action(const struct device * dev,enum pm_device_action action)105 static int led_pwm_pm_action(const struct device *dev,
106 enum pm_device_action action)
107 {
108 const struct led_pwm_config *config = dev->config;
109
110 /* switch all underlying PWM devices to the new state */
111 for (size_t i = 0; i < config->num_leds; i++) {
112 int err;
113 const struct pwm_dt_spec *led = &config->led[i];
114
115 LOG_DBG("PWM %p running pm action %" PRIu32, led->dev, action);
116
117 err = pm_device_action_run(led->dev, action);
118 if (err && (err != -EALREADY)) {
119 LOG_DBG("Cannot switch PWM %p power state (err = %d)", led->dev, err);
120 }
121 }
122
123 return 0;
124 }
125 #endif /* CONFIG_PM_DEVICE */
126
127 static DEVICE_API(led, led_pwm_api) = {
128 .on = led_pwm_on,
129 .off = led_pwm_off,
130 .blink = led_pwm_blink,
131 .set_brightness = led_pwm_set_brightness,
132 };
133
134 #define LED_PWM_DEVICE(id) \
135 \
136 static const struct pwm_dt_spec led_pwm_##id[] = { \
137 DT_INST_FOREACH_CHILD_SEP(id, PWM_DT_SPEC_GET, (,)) \
138 }; \
139 \
140 static const struct led_pwm_config led_pwm_config_##id = { \
141 .num_leds = ARRAY_SIZE(led_pwm_##id), \
142 .led = led_pwm_##id, \
143 }; \
144 \
145 PM_DEVICE_DT_INST_DEFINE(id, led_pwm_pm_action); \
146 \
147 DEVICE_DT_INST_DEFINE(id, &led_pwm_init, \
148 PM_DEVICE_DT_INST_GET(id), NULL, \
149 &led_pwm_config_##id, POST_KERNEL, \
150 CONFIG_LED_INIT_PRIORITY, &led_pwm_api);
151
152 DT_INST_FOREACH_STATUS_OKAY(LED_PWM_DEVICE)
153
