1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Driver for BCM6358 memory-mapped LEDs, based on leds-syscon.c
4 *
5 * Copyright 2015 ��lvaro Fern��ndez Rojas <noltari@gmail.com>
6 */
7#include <linux/delay.h>
8#include <linux/io.h>
9#include <linux/leds.h>
10#include <linux/module.h>
11#include <linux/of.h>
12#include <linux/platform_device.h>
13#include <linux/spinlock.h>
14
15#define BCM6358_REG_MODE		0x0
16#define BCM6358_REG_CTRL		0x4
17
18#define BCM6358_SLED_CLKDIV_MASK	3
19#define BCM6358_SLED_CLKDIV_1		0
20#define BCM6358_SLED_CLKDIV_2		1
21#define BCM6358_SLED_CLKDIV_4		2
22#define BCM6358_SLED_CLKDIV_8		3
23
24#define BCM6358_SLED_POLARITY		BIT(2)
25#define BCM6358_SLED_BUSY		BIT(3)
26
27#define BCM6358_SLED_MAX_COUNT		32
28#define BCM6358_SLED_WAIT		100
29
30/**
31 * struct bcm6358_led - state container for bcm6358 based LEDs
32 * @cdev: LED class device for this LED
33 * @mem: memory resource
34 * @lock: memory lock
35 * @pin: LED pin number
36 * @active_low: LED is active low
37 */
38struct bcm6358_led {
39	struct led_classdev cdev;
40	void __iomem *mem;
41	spinlock_t *lock;
42	unsigned long pin;
43	bool active_low;
44};
45
46static void bcm6358_led_write(void __iomem *reg, unsigned long data)
47{
48#ifdef CONFIG_CPU_BIG_ENDIAN
49	iowrite32be(data, reg);
50#else
51	writel(data, reg);
52#endif
53}
54
55static unsigned long bcm6358_led_read(void __iomem *reg)
56{
57#ifdef CONFIG_CPU_BIG_ENDIAN
58	return ioread32be(reg);
59#else
60	return readl(reg);
61#endif
62}
63
64static unsigned long bcm6358_led_busy(void __iomem *mem)
65{
66	unsigned long val;
67
68	while ((val = bcm6358_led_read(mem + BCM6358_REG_CTRL)) &
69		BCM6358_SLED_BUSY)
70		udelay(BCM6358_SLED_WAIT);
71
72	return val;
73}
74
75static void bcm6358_led_set(struct led_classdev *led_cdev,
76			    enum led_brightness value)
77{
78	struct bcm6358_led *led =
79		container_of(led_cdev, struct bcm6358_led, cdev);
80	unsigned long flags, val;
81
82	spin_lock_irqsave(led->lock, flags);
83	bcm6358_led_busy(led->mem);
84	val = bcm6358_led_read(led->mem + BCM6358_REG_MODE);
85	if ((led->active_low && value == LED_OFF) ||
86	    (!led->active_low && value != LED_OFF))
87		val |= BIT(led->pin);
88	else
89		val &= ~(BIT(led->pin));
90	bcm6358_led_write(led->mem + BCM6358_REG_MODE, val);
91	spin_unlock_irqrestore(led->lock, flags);
92}
93
94static int bcm6358_led(struct device *dev, struct device_node *nc, u32 reg,
95		       void __iomem *mem, spinlock_t *lock)
96{
97	struct led_init_data init_data = {};
98	struct bcm6358_led *led;
99	enum led_default_state state;
100	unsigned long val;
101	int rc;
102
103	led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
104	if (!led)
105		return -ENOMEM;
106
107	led->pin = reg;
108	led->mem = mem;
109	led->lock = lock;
110
111	if (of_property_read_bool(nc, "active-low"))
112		led->active_low = true;
113
114	init_data.fwnode = of_fwnode_handle(nc);
115
116	state = led_init_default_state_get(init_data.fwnode);
117	switch (state) {
118	case LEDS_DEFSTATE_ON:
119		led->cdev.brightness = LED_FULL;
120		break;
121	case LEDS_DEFSTATE_KEEP:
122		val = bcm6358_led_read(led->mem + BCM6358_REG_MODE);
123		val &= BIT(led->pin);
124		if ((led->active_low && !val) || (!led->active_low && val))
125			led->cdev.brightness = LED_FULL;
126		else
127			led->cdev.brightness = LED_OFF;
128		break;
129	default:
130		led->cdev.brightness = LED_OFF;
131	}
132
133	bcm6358_led_set(&led->cdev, led->cdev.brightness);
134
135	led->cdev.brightness_set = bcm6358_led_set;
136
137	rc = devm_led_classdev_register_ext(dev, &led->cdev, &init_data);
138	if (rc < 0)
139		return rc;
140
141	dev_dbg(dev, "registered LED %s\n", led->cdev.name);
142
143	return 0;
144}
145
146static int bcm6358_leds_probe(struct platform_device *pdev)
147{
148	struct device *dev = &pdev->dev;
149	struct device_node *np = dev_of_node(&pdev->dev);
150	struct device_node *child;
151	void __iomem *mem;
152	spinlock_t *lock; /* memory lock */
153	unsigned long val;
154	u32 clk_div;
155
156	mem = devm_platform_ioremap_resource(pdev, 0);
157	if (IS_ERR(mem))
158		return PTR_ERR(mem);
159
160	lock = devm_kzalloc(dev, sizeof(*lock), GFP_KERNEL);
161	if (!lock)
162		return -ENOMEM;
163
164	spin_lock_init(lock);
165
166	val = bcm6358_led_busy(mem);
167	val &= ~(BCM6358_SLED_POLARITY | BCM6358_SLED_CLKDIV_MASK);
168	if (of_property_read_bool(np, "brcm,clk-dat-low"))
169		val |= BCM6358_SLED_POLARITY;
170	of_property_read_u32(np, "brcm,clk-div", &clk_div);
171	switch (clk_div) {
172	case 8:
173		val |= BCM6358_SLED_CLKDIV_8;
174		break;
175	case 4:
176		val |= BCM6358_SLED_CLKDIV_4;
177		break;
178	case 2:
179		val |= BCM6358_SLED_CLKDIV_2;
180		break;
181	default:
182		val |= BCM6358_SLED_CLKDIV_1;
183		break;
184	}
185	bcm6358_led_write(mem + BCM6358_REG_CTRL, val);
186
187	for_each_available_child_of_node(np, child) {
188		int rc;
189		u32 reg;
190
191		if (of_property_read_u32(child, "reg", &reg))
192			continue;
193
194		if (reg >= BCM6358_SLED_MAX_COUNT) {
195			dev_err(dev, "invalid LED (%u >= %d)\n", reg,
196				BCM6358_SLED_MAX_COUNT);
197			continue;
198		}
199
200		rc = bcm6358_led(dev, child, reg, mem, lock);
201		if (rc < 0) {
202			of_node_put(child);
203			return rc;
204		}
205	}
206
207	return 0;
208}
209
210static const struct of_device_id bcm6358_leds_of_match[] = {
211	{ .compatible = "brcm,bcm6358-leds", },
212	{ },
213};
214MODULE_DEVICE_TABLE(of, bcm6358_leds_of_match);
215
216static struct platform_driver bcm6358_leds_driver = {
217	.probe = bcm6358_leds_probe,
218	.driver = {
219		.name = "leds-bcm6358",
220		.of_match_table = bcm6358_leds_of_match,
221	},
222};
223
224module_platform_driver(bcm6358_leds_driver);
225
226MODULE_AUTHOR("��lvaro Fern��ndez Rojas <noltari@gmail.com>");
227MODULE_DESCRIPTION("LED driver for BCM6358 controllers");
228MODULE_LICENSE("GPL v2");
229MODULE_ALIAS("platform:leds-bcm6358");
230