1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * NCP5623 Multi-LED Driver
4 *
5 * Author: Abdel Alkuor <alkuor@gmail.com>
6 * Datasheet: https://www.onsemi.com/pdf/datasheet/ncp5623-d.pdf
7 */
8
9#include <linux/i2c.h>
10#include <linux/module.h>
11
12#include <linux/led-class-multicolor.h>
13
14#define NCP5623_FUNCTION_OFFSET		0x5
15#define NCP5623_REG(x)			((x) << NCP5623_FUNCTION_OFFSET)
16
17#define NCP5623_SHUTDOWN_REG		NCP5623_REG(0x0)
18#define NCP5623_ILED_REG		NCP5623_REG(0x1)
19#define NCP5623_PWM_REG(index)		NCP5623_REG(0x2 + (index))
20#define NCP5623_UPWARD_STEP_REG		NCP5623_REG(0x5)
21#define NCP5623_DOWNWARD_STEP_REG	NCP5623_REG(0x6)
22#define NCP5623_DIMMING_TIME_REG	NCP5623_REG(0x7)
23
24#define NCP5623_MAX_BRIGHTNESS		0x1f
25#define NCP5623_MAX_DIM_TIME_MS		240
26#define NCP5623_DIM_STEP_MS		8
27
28struct ncp5623 {
29	struct i2c_client *client;
30	struct led_classdev_mc mc_dev;
31	struct mutex lock;
32
33	int current_brightness;
34	unsigned long delay;
35};
36
37static int ncp5623_write(struct i2c_client *client, u8 reg, u8 data)
38{
39	return i2c_smbus_write_byte_data(client, reg | data, 0);
40}
41
42static int ncp5623_brightness_set(struct led_classdev *cdev,
43				  enum led_brightness brightness)
44{
45	struct led_classdev_mc *mc_cdev = lcdev_to_mccdev(cdev);
46	struct ncp5623 *ncp = container_of(mc_cdev, struct ncp5623, mc_dev);
47	int ret;
48
49	guard(mutex)(&ncp->lock);
50
51	if (ncp->delay && time_is_after_jiffies(ncp->delay))
52		return -EBUSY;
53
54	ncp->delay = 0;
55
56	for (int i = 0; i < mc_cdev->num_colors; i++) {
57		ret = ncp5623_write(ncp->client,
58				    NCP5623_PWM_REG(mc_cdev->subled_info[i].channel),
59				    min(mc_cdev->subled_info[i].intensity,
60					NCP5623_MAX_BRIGHTNESS));
61		if (ret)
62			return ret;
63	}
64
65	ret = ncp5623_write(ncp->client, NCP5623_DIMMING_TIME_REG, 0);
66	if (ret)
67		return ret;
68
69	ret = ncp5623_write(ncp->client, NCP5623_ILED_REG, brightness);
70	if (ret)
71		return ret;
72
73	ncp->current_brightness = brightness;
74
75	return 0;
76}
77
78static int ncp5623_pattern_set(struct led_classdev *cdev,
79			       struct led_pattern *pattern,
80			       u32 len, int repeat)
81{
82	struct led_classdev_mc *mc_cdev = lcdev_to_mccdev(cdev);
83	struct ncp5623 *ncp = container_of(mc_cdev, struct ncp5623, mc_dev);
84	int brightness_diff;
85	u8 reg;
86	int ret;
87
88	guard(mutex)(&ncp->lock);
89
90	if (ncp->delay && time_is_after_jiffies(ncp->delay))
91		return -EBUSY;
92
93	ncp->delay = 0;
94
95	if (pattern[0].delta_t > NCP5623_MAX_DIM_TIME_MS ||
96	   (pattern[0].delta_t % NCP5623_DIM_STEP_MS) != 0)
97		return -EINVAL;
98
99	brightness_diff = pattern[0].brightness - ncp->current_brightness;
100
101	if (brightness_diff == 0)
102		return 0;
103
104	if (pattern[0].delta_t) {
105		if (brightness_diff > 0)
106			reg = NCP5623_UPWARD_STEP_REG;
107		else
108			reg = NCP5623_DOWNWARD_STEP_REG;
109	} else {
110		reg = NCP5623_ILED_REG;
111	}
112
113	ret = ncp5623_write(ncp->client, reg,
114			    min(pattern[0].brightness, NCP5623_MAX_BRIGHTNESS));
115	if (ret)
116		return ret;
117
118	ret = ncp5623_write(ncp->client,
119			    NCP5623_DIMMING_TIME_REG,
120			    pattern[0].delta_t / NCP5623_DIM_STEP_MS);
121	if (ret)
122		return ret;
123
124	/*
125	 * During testing, when the brightness difference is 1, for some
126	 * unknown reason, the time factor it takes to change to the new
127	 * value is the longest time possible. Otherwise, the time factor
128	 * is simply the brightness difference.
129	 *
130	 * For example:
131	 * current_brightness = 20 and new_brightness = 21 then the time it
132	 * takes to set the new brightness increments to the maximum possible
133	 * brightness from 20 then from 0 to 21.
134	 * time_factor = max_brightness - 20 + 21
135	 */
136	if (abs(brightness_diff) == 1)
137		ncp->delay = NCP5623_MAX_BRIGHTNESS + brightness_diff;
138	else
139		ncp->delay = abs(brightness_diff);
140
141	ncp->delay = msecs_to_jiffies(ncp->delay * pattern[0].delta_t) + jiffies;
142
143	ncp->current_brightness = pattern[0].brightness;
144
145	return 0;
146}
147
148static int ncp5623_pattern_clear(struct led_classdev *led_cdev)
149{
150	return 0;
151}
152
153static int ncp5623_probe(struct i2c_client *client)
154{
155	struct device *dev = &client->dev;
156	struct fwnode_handle *mc_node, *led_node;
157	struct led_init_data init_data = { };
158	int num_subleds = 0;
159	struct ncp5623 *ncp;
160	struct mc_subled *subled_info;
161	u32 color_index;
162	u32 reg;
163	int ret;
164
165	ncp = devm_kzalloc(dev, sizeof(*ncp), GFP_KERNEL);
166	if (!ncp)
167		return -ENOMEM;
168
169	ncp->client = client;
170
171	mc_node = device_get_named_child_node(dev, "multi-led");
172	if (!mc_node)
173		return -EINVAL;
174
175	fwnode_for_each_child_node(mc_node, led_node)
176		num_subleds++;
177
178	subled_info = devm_kcalloc(dev, num_subleds, sizeof(*subled_info), GFP_KERNEL);
179	if (!subled_info) {
180		ret = -ENOMEM;
181		goto release_mc_node;
182	}
183
184	fwnode_for_each_available_child_node(mc_node, led_node) {
185		ret = fwnode_property_read_u32(led_node, "color", &color_index);
186		if (ret) {
187			fwnode_handle_put(led_node);
188			goto release_mc_node;
189		}
190
191		ret = fwnode_property_read_u32(led_node, "reg", &reg);
192		if (ret) {
193			fwnode_handle_put(led_node);
194			goto release_mc_node;
195		}
196
197		subled_info[ncp->mc_dev.num_colors].channel = reg;
198		subled_info[ncp->mc_dev.num_colors++].color_index = color_index;
199	}
200
201	init_data.fwnode = mc_node;
202
203	ncp->mc_dev.led_cdev.max_brightness = NCP5623_MAX_BRIGHTNESS;
204	ncp->mc_dev.subled_info = subled_info;
205	ncp->mc_dev.led_cdev.brightness_set_blocking = ncp5623_brightness_set;
206	ncp->mc_dev.led_cdev.pattern_set = ncp5623_pattern_set;
207	ncp->mc_dev.led_cdev.pattern_clear = ncp5623_pattern_clear;
208	ncp->mc_dev.led_cdev.default_trigger = "pattern";
209
210	mutex_init(&ncp->lock);
211	i2c_set_clientdata(client, ncp);
212
213	ret = led_classdev_multicolor_register_ext(dev, &ncp->mc_dev, &init_data);
214	if (ret)
215		goto destroy_lock;
216
217	return 0;
218
219destroy_lock:
220	mutex_destroy(&ncp->lock);
221
222release_mc_node:
223	fwnode_handle_put(mc_node);
224
225	return ret;
226}
227
228static void ncp5623_remove(struct i2c_client *client)
229{
230	struct ncp5623 *ncp = i2c_get_clientdata(client);
231
232	mutex_lock(&ncp->lock);
233	ncp->delay = 0;
234	mutex_unlock(&ncp->lock);
235
236	ncp5623_write(client, NCP5623_DIMMING_TIME_REG, 0);
237	led_classdev_multicolor_unregister(&ncp->mc_dev);
238	mutex_destroy(&ncp->lock);
239}
240
241static void ncp5623_shutdown(struct i2c_client *client)
242{
243	struct ncp5623 *ncp = i2c_get_clientdata(client);
244
245	if (!(ncp->mc_dev.led_cdev.flags & LED_RETAIN_AT_SHUTDOWN))
246		ncp5623_write(client, NCP5623_SHUTDOWN_REG, 0);
247
248	mutex_destroy(&ncp->lock);
249}
250
251static const struct of_device_id ncp5623_id[] = {
252	{ .compatible = "onnn,ncp5623" },
253	{ }
254};
255MODULE_DEVICE_TABLE(of, ncp5623_id);
256
257static struct i2c_driver ncp5623_i2c_driver = {
258	.driver	= {
259		.name = "ncp5623",
260		.of_match_table = ncp5623_id,
261	},
262	.probe = ncp5623_probe,
263	.remove = ncp5623_remove,
264	.shutdown = ncp5623_shutdown,
265};
266
267module_i2c_driver(ncp5623_i2c_driver);
268
269MODULE_AUTHOR("Abdel Alkuor <alkuor@gmail.com>");
270MODULE_DESCRIPTION("NCP5623 Multi-LED driver");
271MODULE_LICENSE("GPL");
272