1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * leds-ns2.c - Driver for the Network Space v2 (and parents) dual-GPIO LED
4 *
5 * Copyright (C) 2010 LaCie
6 *
7 * Author: Simon Guinot <sguinot@lacie.com>
8 *
9 * Based on leds-gpio.c by Raphael Assenat <raph@8d.com>
10 */
11
12#include <linux/kernel.h>
13#include <linux/platform_device.h>
14#include <linux/slab.h>
15#include <linux/gpio/consumer.h>
16#include <linux/leds.h>
17#include <linux/module.h>
18#include <linux/of.h>
19#include "leds.h"
20
21enum ns2_led_modes {
22	NS_V2_LED_OFF,
23	NS_V2_LED_ON,
24	NS_V2_LED_SATA,
25};
26
27/*
28 * If the size of this structure or types of its members is changed,
29 * the filling of array modval in function ns2_led_register must be changed
30 * accordingly.
31 */
32struct ns2_led_modval {
33	u32			mode;
34	u32			cmd_level;
35	u32			slow_level;
36} __packed;
37
38/*
39 * The Network Space v2 dual-GPIO LED is wired to a CPLD. Three different LED
40 * modes are available: off, on and SATA activity blinking. The LED modes are
41 * controlled through two GPIOs (command and slow): each combination of values
42 * for the command/slow GPIOs corresponds to a LED mode.
43 */
44
45struct ns2_led {
46	struct led_classdev	cdev;
47	struct gpio_desc	*cmd;
48	struct gpio_desc	*slow;
49	bool			can_sleep;
50	unsigned char		sata; /* True when SATA mode active. */
51	rwlock_t		rw_lock; /* Lock GPIOs. */
52	int			num_modes;
53	struct ns2_led_modval	*modval;
54};
55
56static int ns2_led_get_mode(struct ns2_led *led, enum ns2_led_modes *mode)
57{
58	int i;
59	int cmd_level;
60	int slow_level;
61
62	cmd_level = gpiod_get_value_cansleep(led->cmd);
63	slow_level = gpiod_get_value_cansleep(led->slow);
64
65	for (i = 0; i < led->num_modes; i++) {
66		if (cmd_level == led->modval[i].cmd_level &&
67		    slow_level == led->modval[i].slow_level) {
68			*mode = led->modval[i].mode;
69			return 0;
70		}
71	}
72
73	return -EINVAL;
74}
75
76static void ns2_led_set_mode(struct ns2_led *led, enum ns2_led_modes mode)
77{
78	int i;
79	unsigned long flags;
80
81	for (i = 0; i < led->num_modes; i++)
82		if (mode == led->modval[i].mode)
83			break;
84
85	if (i == led->num_modes)
86		return;
87
88	write_lock_irqsave(&led->rw_lock, flags);
89
90	if (!led->can_sleep) {
91		gpiod_set_value(led->cmd, led->modval[i].cmd_level);
92		gpiod_set_value(led->slow, led->modval[i].slow_level);
93		goto exit_unlock;
94	}
95
96	gpiod_set_value_cansleep(led->cmd, led->modval[i].cmd_level);
97	gpiod_set_value_cansleep(led->slow, led->modval[i].slow_level);
98
99exit_unlock:
100	write_unlock_irqrestore(&led->rw_lock, flags);
101}
102
103static void ns2_led_set(struct led_classdev *led_cdev,
104			enum led_brightness value)
105{
106	struct ns2_led *led = container_of(led_cdev, struct ns2_led, cdev);
107	enum ns2_led_modes mode;
108
109	if (value == LED_OFF)
110		mode = NS_V2_LED_OFF;
111	else if (led->sata)
112		mode = NS_V2_LED_SATA;
113	else
114		mode = NS_V2_LED_ON;
115
116	ns2_led_set_mode(led, mode);
117}
118
119static int ns2_led_set_blocking(struct led_classdev *led_cdev,
120			enum led_brightness value)
121{
122	ns2_led_set(led_cdev, value);
123	return 0;
124}
125
126static ssize_t ns2_led_sata_store(struct device *dev,
127				  struct device_attribute *attr,
128				  const char *buff, size_t count)
129{
130	struct led_classdev *led_cdev = dev_get_drvdata(dev);
131	struct ns2_led *led = container_of(led_cdev, struct ns2_led, cdev);
132	int ret;
133	unsigned long enable;
134
135	ret = kstrtoul(buff, 10, &enable);
136	if (ret < 0)
137		return ret;
138
139	enable = !!enable;
140
141	if (led->sata == enable)
142		goto exit;
143
144	led->sata = enable;
145
146	if (!led_get_brightness(led_cdev))
147		goto exit;
148
149	if (enable)
150		ns2_led_set_mode(led, NS_V2_LED_SATA);
151	else
152		ns2_led_set_mode(led, NS_V2_LED_ON);
153
154exit:
155	return count;
156}
157
158static ssize_t ns2_led_sata_show(struct device *dev,
159				 struct device_attribute *attr, char *buf)
160{
161	struct led_classdev *led_cdev = dev_get_drvdata(dev);
162	struct ns2_led *led = container_of(led_cdev, struct ns2_led, cdev);
163
164	return sprintf(buf, "%d\n", led->sata);
165}
166
167static DEVICE_ATTR(sata, 0644, ns2_led_sata_show, ns2_led_sata_store);
168
169static struct attribute *ns2_led_attrs[] = {
170	&dev_attr_sata.attr,
171	NULL
172};
173ATTRIBUTE_GROUPS(ns2_led);
174
175static int ns2_led_register(struct device *dev, struct fwnode_handle *node,
176			    struct ns2_led *led)
177{
178	struct led_init_data init_data = {};
179	struct ns2_led_modval *modval;
180	enum ns2_led_modes mode;
181	int nmodes, ret;
182
183	led->cmd = devm_fwnode_gpiod_get_index(dev, node, "cmd", 0, GPIOD_ASIS,
184					       fwnode_get_name(node));
185	if (IS_ERR(led->cmd))
186		return PTR_ERR(led->cmd);
187
188	led->slow = devm_fwnode_gpiod_get_index(dev, node, "slow", 0,
189						GPIOD_ASIS,
190						fwnode_get_name(node));
191	if (IS_ERR(led->slow))
192		return PTR_ERR(led->slow);
193
194	ret = fwnode_property_count_u32(node, "modes-map");
195	if (ret < 0 || ret % 3) {
196		dev_err(dev, "Missing or malformed modes-map for %pfw\n", node);
197		return -EINVAL;
198	}
199
200	nmodes = ret / 3;
201	modval = devm_kcalloc(dev, nmodes, sizeof(*modval), GFP_KERNEL);
202	if (!modval)
203		return -ENOMEM;
204
205	fwnode_property_read_u32_array(node, "modes-map", (void *)modval,
206				       nmodes * 3);
207
208	rwlock_init(&led->rw_lock);
209
210	led->cdev.blink_set = NULL;
211	led->cdev.flags |= LED_CORE_SUSPENDRESUME;
212	led->cdev.groups = ns2_led_groups;
213	led->can_sleep = gpiod_cansleep(led->cmd) || gpiod_cansleep(led->slow);
214	if (led->can_sleep)
215		led->cdev.brightness_set_blocking = ns2_led_set_blocking;
216	else
217		led->cdev.brightness_set = ns2_led_set;
218	led->num_modes = nmodes;
219	led->modval = modval;
220
221	ret = ns2_led_get_mode(led, &mode);
222	if (ret < 0)
223		return ret;
224
225	/* Set LED initial state. */
226	led->sata = (mode == NS_V2_LED_SATA) ? 1 : 0;
227	led->cdev.brightness = (mode == NS_V2_LED_OFF) ? LED_OFF : LED_FULL;
228
229	init_data.fwnode = node;
230
231	ret = devm_led_classdev_register_ext(dev, &led->cdev, &init_data);
232	if (ret)
233		dev_err(dev, "Failed to register LED for node %pfw\n", node);
234
235	return ret;
236}
237
238static int ns2_led_probe(struct platform_device *pdev)
239{
240	struct device *dev = &pdev->dev;
241	struct fwnode_handle *child;
242	struct ns2_led *leds;
243	int count;
244	int ret;
245
246	count = device_get_child_node_count(dev);
247	if (!count)
248		return -ENODEV;
249
250	leds = devm_kcalloc(dev, count, sizeof(*leds), GFP_KERNEL);
251	if (!leds)
252		return -ENOMEM;
253
254	device_for_each_child_node(dev, child) {
255		ret = ns2_led_register(dev, child, leds++);
256		if (ret) {
257			fwnode_handle_put(child);
258			return ret;
259		}
260	}
261
262	return 0;
263}
264
265static const struct of_device_id of_ns2_leds_match[] = {
266	{ .compatible = "lacie,ns2-leds", },
267	{},
268};
269MODULE_DEVICE_TABLE(of, of_ns2_leds_match);
270
271static struct platform_driver ns2_led_driver = {
272	.probe		= ns2_led_probe,
273	.driver		= {
274		.name		= "leds-ns2",
275		.of_match_table	= of_ns2_leds_match,
276	},
277};
278
279module_platform_driver(ns2_led_driver);
280
281MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
282MODULE_DESCRIPTION("Network Space v2 LED driver");
283MODULE_LICENSE("GPL");
284MODULE_ALIAS("platform:leds-ns2");
285