1818d03b3SSven Schwermer // SPDX-License-Identifier: GPL-2.0-only
2818d03b3SSven Schwermer /*
3818d03b3SSven Schwermer * PWM-based multi-color LED control
4818d03b3SSven Schwermer *
5818d03b3SSven Schwermer * Copyright 2022 Sven Schwermer <sven.schwermer@disruptive-technologies.com>
6818d03b3SSven Schwermer */
7818d03b3SSven Schwermer
8818d03b3SSven Schwermer #include <linux/err.h>
9818d03b3SSven Schwermer #include <linux/kernel.h>
10818d03b3SSven Schwermer #include <linux/led-class-multicolor.h>
11818d03b3SSven Schwermer #include <linux/leds.h>
12818d03b3SSven Schwermer #include <linux/mod_devicetable.h>
13818d03b3SSven Schwermer #include <linux/module.h>
14818d03b3SSven Schwermer #include <linux/mutex.h>
15818d03b3SSven Schwermer #include <linux/platform_device.h>
16818d03b3SSven Schwermer #include <linux/property.h>
17818d03b3SSven Schwermer #include <linux/pwm.h>
18818d03b3SSven Schwermer
19818d03b3SSven Schwermer struct pwm_led {
20818d03b3SSven Schwermer struct pwm_device *pwm;
21818d03b3SSven Schwermer struct pwm_state state;
223dd7ed58SEmil Renner Berthing bool active_low;
23818d03b3SSven Schwermer };
24818d03b3SSven Schwermer
25818d03b3SSven Schwermer struct pwm_mc_led {
26818d03b3SSven Schwermer struct led_classdev_mc mc_cdev;
27818d03b3SSven Schwermer struct mutex lock;
28818d03b3SSven Schwermer struct pwm_led leds[];
29818d03b3SSven Schwermer };
30818d03b3SSven Schwermer
led_pwm_mc_set(struct led_classdev * cdev,enum led_brightness brightness)31818d03b3SSven Schwermer static int led_pwm_mc_set(struct led_classdev *cdev,
32818d03b3SSven Schwermer enum led_brightness brightness)
33818d03b3SSven Schwermer {
34818d03b3SSven Schwermer struct led_classdev_mc *mc_cdev = lcdev_to_mccdev(cdev);
35818d03b3SSven Schwermer struct pwm_mc_led *priv = container_of(mc_cdev, struct pwm_mc_led, mc_cdev);
36818d03b3SSven Schwermer unsigned long long duty;
37818d03b3SSven Schwermer int ret = 0;
38818d03b3SSven Schwermer int i;
39818d03b3SSven Schwermer
40818d03b3SSven Schwermer led_mc_calc_color_components(mc_cdev, brightness);
41818d03b3SSven Schwermer
42818d03b3SSven Schwermer mutex_lock(&priv->lock);
43818d03b3SSven Schwermer
44818d03b3SSven Schwermer for (i = 0; i < mc_cdev->num_colors; i++) {
45818d03b3SSven Schwermer duty = priv->leds[i].state.period;
46818d03b3SSven Schwermer duty *= mc_cdev->subled_info[i].brightness;
47818d03b3SSven Schwermer do_div(duty, cdev->max_brightness);
48818d03b3SSven Schwermer
493dd7ed58SEmil Renner Berthing if (priv->leds[i].active_low)
503dd7ed58SEmil Renner Berthing duty = priv->leds[i].state.period - duty;
513dd7ed58SEmil Renner Berthing
52818d03b3SSven Schwermer priv->leds[i].state.duty_cycle = duty;
53818d03b3SSven Schwermer priv->leds[i].state.enabled = duty > 0;
54a10c3d5fSSean Young ret = pwm_apply_might_sleep(priv->leds[i].pwm,
55818d03b3SSven Schwermer &priv->leds[i].state);
56818d03b3SSven Schwermer if (ret)
57818d03b3SSven Schwermer break;
58818d03b3SSven Schwermer }
59818d03b3SSven Schwermer
60818d03b3SSven Schwermer mutex_unlock(&priv->lock);
61818d03b3SSven Schwermer
62818d03b3SSven Schwermer return ret;
63818d03b3SSven Schwermer }
64818d03b3SSven Schwermer
iterate_subleds(struct device * dev,struct pwm_mc_led * priv,struct fwnode_handle * mcnode)65818d03b3SSven Schwermer static int iterate_subleds(struct device *dev, struct pwm_mc_led *priv,
66818d03b3SSven Schwermer struct fwnode_handle *mcnode)
67818d03b3SSven Schwermer {
68818d03b3SSven Schwermer struct mc_subled *subled = priv->mc_cdev.subled_info;
69818d03b3SSven Schwermer struct fwnode_handle *fwnode;
70818d03b3SSven Schwermer struct pwm_led *pwmled;
71818d03b3SSven Schwermer u32 color;
72818d03b3SSven Schwermer int ret;
73818d03b3SSven Schwermer
74818d03b3SSven Schwermer /* iterate over the nodes inside the multi-led node */
75818d03b3SSven Schwermer fwnode_for_each_child_node(mcnode, fwnode) {
76818d03b3SSven Schwermer pwmled = &priv->leds[priv->mc_cdev.num_colors];
77818d03b3SSven Schwermer pwmled->pwm = devm_fwnode_pwm_get(dev, fwnode, NULL);
78818d03b3SSven Schwermer if (IS_ERR(pwmled->pwm)) {
79399e7aa8SEmil Renner Berthing ret = dev_err_probe(dev, PTR_ERR(pwmled->pwm), "unable to request PWM\n");
80818d03b3SSven Schwermer goto release_fwnode;
81818d03b3SSven Schwermer }
82818d03b3SSven Schwermer pwm_init_state(pwmled->pwm, &pwmled->state);
833dd7ed58SEmil Renner Berthing pwmled->active_low = fwnode_property_read_bool(fwnode, "active-low");
84818d03b3SSven Schwermer
85818d03b3SSven Schwermer ret = fwnode_property_read_u32(fwnode, "color", &color);
86818d03b3SSven Schwermer if (ret) {
87818d03b3SSven Schwermer dev_err(dev, "cannot read color: %d\n", ret);
88818d03b3SSven Schwermer goto release_fwnode;
89818d03b3SSven Schwermer }
90818d03b3SSven Schwermer
91818d03b3SSven Schwermer subled[priv->mc_cdev.num_colors].color_index = color;
92818d03b3SSven Schwermer priv->mc_cdev.num_colors++;
93818d03b3SSven Schwermer }
94818d03b3SSven Schwermer
95818d03b3SSven Schwermer return 0;
96818d03b3SSven Schwermer
97818d03b3SSven Schwermer release_fwnode:
98818d03b3SSven Schwermer fwnode_handle_put(fwnode);
99818d03b3SSven Schwermer return ret;
100818d03b3SSven Schwermer }
101818d03b3SSven Schwermer
led_pwm_mc_probe(struct platform_device * pdev)102818d03b3SSven Schwermer static int led_pwm_mc_probe(struct platform_device *pdev)
103818d03b3SSven Schwermer {
104818d03b3SSven Schwermer struct fwnode_handle *mcnode, *fwnode;
105818d03b3SSven Schwermer struct led_init_data init_data = {};
106818d03b3SSven Schwermer struct led_classdev *cdev;
107818d03b3SSven Schwermer struct mc_subled *subled;
108818d03b3SSven Schwermer struct pwm_mc_led *priv;
109818d03b3SSven Schwermer int count = 0;
110818d03b3SSven Schwermer int ret = 0;
111818d03b3SSven Schwermer
112818d03b3SSven Schwermer mcnode = device_get_named_child_node(&pdev->dev, "multi-led");
113818d03b3SSven Schwermer if (!mcnode)
114818d03b3SSven Schwermer return dev_err_probe(&pdev->dev, -ENODEV,
115818d03b3SSven Schwermer "expected multi-led node\n");
116818d03b3SSven Schwermer
117818d03b3SSven Schwermer /* count the nodes inside the multi-led node */
118818d03b3SSven Schwermer fwnode_for_each_child_node(mcnode, fwnode)
119818d03b3SSven Schwermer count++;
120818d03b3SSven Schwermer
121818d03b3SSven Schwermer priv = devm_kzalloc(&pdev->dev, struct_size(priv, leds, count),
122818d03b3SSven Schwermer GFP_KERNEL);
123818d03b3SSven Schwermer if (!priv) {
124818d03b3SSven Schwermer ret = -ENOMEM;
125818d03b3SSven Schwermer goto release_mcnode;
126818d03b3SSven Schwermer }
127818d03b3SSven Schwermer mutex_init(&priv->lock);
128818d03b3SSven Schwermer
129818d03b3SSven Schwermer subled = devm_kcalloc(&pdev->dev, count, sizeof(*subled), GFP_KERNEL);
130818d03b3SSven Schwermer if (!subled) {
131818d03b3SSven Schwermer ret = -ENOMEM;
132818d03b3SSven Schwermer goto release_mcnode;
133818d03b3SSven Schwermer }
134818d03b3SSven Schwermer priv->mc_cdev.subled_info = subled;
135818d03b3SSven Schwermer
136818d03b3SSven Schwermer /* init the multicolor's LED class device */
137818d03b3SSven Schwermer cdev = &priv->mc_cdev.led_cdev;
138818d03b3SSven Schwermer fwnode_property_read_u32(mcnode, "max-brightness",
139818d03b3SSven Schwermer &cdev->max_brightness);
140818d03b3SSven Schwermer cdev->flags = LED_CORE_SUSPENDRESUME;
141818d03b3SSven Schwermer cdev->brightness_set_blocking = led_pwm_mc_set;
142818d03b3SSven Schwermer
143818d03b3SSven Schwermer ret = iterate_subleds(&pdev->dev, priv, mcnode);
144818d03b3SSven Schwermer if (ret)
145818d03b3SSven Schwermer goto release_mcnode;
146818d03b3SSven Schwermer
147818d03b3SSven Schwermer init_data.fwnode = mcnode;
148818d03b3SSven Schwermer ret = devm_led_classdev_multicolor_register_ext(&pdev->dev,
149818d03b3SSven Schwermer &priv->mc_cdev,
150818d03b3SSven Schwermer &init_data);
151818d03b3SSven Schwermer if (ret) {
152818d03b3SSven Schwermer dev_err(&pdev->dev,
153818d03b3SSven Schwermer "failed to register multicolor PWM led for %s: %d\n",
154818d03b3SSven Schwermer cdev->name, ret);
155818d03b3SSven Schwermer goto release_mcnode;
156818d03b3SSven Schwermer }
157818d03b3SSven Schwermer
158818d03b3SSven Schwermer ret = led_pwm_mc_set(cdev, cdev->brightness);
159818d03b3SSven Schwermer if (ret)
160818d03b3SSven Schwermer return dev_err_probe(&pdev->dev, ret,
161f3ef9d66SChristophe JAILLET "failed to set led PWM value for %s\n",
162f3ef9d66SChristophe JAILLET cdev->name);
163818d03b3SSven Schwermer
164818d03b3SSven Schwermer platform_set_drvdata(pdev, priv);
165818d03b3SSven Schwermer return 0;
166818d03b3SSven Schwermer
167818d03b3SSven Schwermer release_mcnode:
168818d03b3SSven Schwermer fwnode_handle_put(mcnode);
169818d03b3SSven Schwermer return ret;
170818d03b3SSven Schwermer }
171818d03b3SSven Schwermer
172818d03b3SSven Schwermer static const struct of_device_id of_pwm_leds_mc_match[] = {
173818d03b3SSven Schwermer { .compatible = "pwm-leds-multicolor", },
174818d03b3SSven Schwermer {}
175818d03b3SSven Schwermer };
176818d03b3SSven Schwermer MODULE_DEVICE_TABLE(of, of_pwm_leds_mc_match);
177818d03b3SSven Schwermer
178818d03b3SSven Schwermer static struct platform_driver led_pwm_mc_driver = {
179818d03b3SSven Schwermer .probe = led_pwm_mc_probe,
180818d03b3SSven Schwermer .driver = {
181818d03b3SSven Schwermer .name = "leds_pwm_multicolor",
182818d03b3SSven Schwermer .of_match_table = of_pwm_leds_mc_match,
183818d03b3SSven Schwermer },
184818d03b3SSven Schwermer };
185818d03b3SSven Schwermer module_platform_driver(led_pwm_mc_driver);
186818d03b3SSven Schwermer
187818d03b3SSven Schwermer MODULE_AUTHOR("Sven Schwermer <sven.schwermer@disruptive-technologies.com>");
188818d03b3SSven Schwermer MODULE_DESCRIPTION("multi-color PWM LED driver");
189818d03b3SSven Schwermer MODULE_LICENSE("GPL v2");
190818d03b3SSven Schwermer MODULE_ALIAS("platform:leds-pwm-multicolor");
191