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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 Álvaro Fernández 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 const char *state;
100 int rc;
101
102 led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
103 if (!led)
104 return -ENOMEM;
105
106 led->pin = reg;
107 led->mem = mem;
108 led->lock = lock;
109
110 if (of_property_read_bool(nc, "active-low"))
111 led->active_low = true;
112
113 if (!of_property_read_string(nc, "default-state", &state)) {
114 if (!strcmp(state, "on")) {
115 led->cdev.brightness = LED_FULL;
116 } else if (!strcmp(state, "keep")) {
117 unsigned long val;
118 val = bcm6358_led_read(led->mem + BCM6358_REG_MODE);
119 val &= BIT(led->pin);
120 if ((led->active_low && !val) ||
121 (!led->active_low && val))
122 led->cdev.brightness = LED_FULL;
123 else
124 led->cdev.brightness = LED_OFF;
125 } else {
126 led->cdev.brightness = LED_OFF;
127 }
128 } else {
129 led->cdev.brightness = LED_OFF;
130 }
131
132 bcm6358_led_set(&led->cdev, led->cdev.brightness);
133
134 led->cdev.brightness_set = bcm6358_led_set;
135 init_data.fwnode = of_fwnode_handle(nc);
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", ®))
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("Álvaro Fernández Rojas <noltari@gmail.com>");
227MODULE_DESCRIPTION("LED driver for BCM6358 controllers");
228MODULE_LICENSE("GPL v2");
229MODULE_ALIAS("platform:leds-bcm6358");
1/*
2 * Driver for BCM6358 memory-mapped LEDs, based on leds-syscon.c
3 *
4 * Copyright 2015 Álvaro Fernández Rojas <noltari@gmail.com>
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the
8 * Free Software Foundation; either version 2 of the License, or (at your
9 * option) any later version.
10 */
11#include <linux/delay.h>
12#include <linux/io.h>
13#include <linux/leds.h>
14#include <linux/module.h>
15#include <linux/of.h>
16#include <linux/platform_device.h>
17#include <linux/spinlock.h>
18
19#define BCM6358_REG_MODE 0x0
20#define BCM6358_REG_CTRL 0x4
21
22#define BCM6358_SLED_CLKDIV_MASK 3
23#define BCM6358_SLED_CLKDIV_1 0
24#define BCM6358_SLED_CLKDIV_2 1
25#define BCM6358_SLED_CLKDIV_4 2
26#define BCM6358_SLED_CLKDIV_8 3
27
28#define BCM6358_SLED_POLARITY BIT(2)
29#define BCM6358_SLED_BUSY BIT(3)
30
31#define BCM6358_SLED_MAX_COUNT 32
32#define BCM6358_SLED_WAIT 100
33
34/**
35 * struct bcm6358_led - state container for bcm6358 based LEDs
36 * @cdev: LED class device for this LED
37 * @mem: memory resource
38 * @lock: memory lock
39 * @pin: LED pin number
40 * @active_low: LED is active low
41 */
42struct bcm6358_led {
43 struct led_classdev cdev;
44 void __iomem *mem;
45 spinlock_t *lock;
46 unsigned long pin;
47 bool active_low;
48};
49
50static void bcm6358_led_write(void __iomem *reg, unsigned long data)
51{
52#ifdef CONFIG_CPU_BIG_ENDIAN
53 iowrite32be(data, reg);
54#else
55 writel(data, reg);
56#endif
57}
58
59static unsigned long bcm6358_led_read(void __iomem *reg)
60{
61#ifdef CONFIG_CPU_BIG_ENDIAN
62 return ioread32be(reg);
63#else
64 return readl(reg);
65#endif
66}
67
68static unsigned long bcm6358_led_busy(void __iomem *mem)
69{
70 unsigned long val;
71
72 while ((val = bcm6358_led_read(mem + BCM6358_REG_CTRL)) &
73 BCM6358_SLED_BUSY)
74 udelay(BCM6358_SLED_WAIT);
75
76 return val;
77}
78
79static void bcm6358_led_set(struct led_classdev *led_cdev,
80 enum led_brightness value)
81{
82 struct bcm6358_led *led =
83 container_of(led_cdev, struct bcm6358_led, cdev);
84 unsigned long flags, val;
85
86 spin_lock_irqsave(led->lock, flags);
87 bcm6358_led_busy(led->mem);
88 val = bcm6358_led_read(led->mem + BCM6358_REG_MODE);
89 if ((led->active_low && value == LED_OFF) ||
90 (!led->active_low && value != LED_OFF))
91 val |= BIT(led->pin);
92 else
93 val &= ~(BIT(led->pin));
94 bcm6358_led_write(led->mem + BCM6358_REG_MODE, val);
95 spin_unlock_irqrestore(led->lock, flags);
96}
97
98static int bcm6358_led(struct device *dev, struct device_node *nc, u32 reg,
99 void __iomem *mem, spinlock_t *lock)
100{
101 struct bcm6358_led *led;
102 const char *state;
103 int rc;
104
105 led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
106 if (!led)
107 return -ENOMEM;
108
109 led->pin = reg;
110 led->mem = mem;
111 led->lock = lock;
112
113 if (of_property_read_bool(nc, "active-low"))
114 led->active_low = true;
115
116 led->cdev.name = of_get_property(nc, "label", NULL) ? : nc->name;
117 led->cdev.default_trigger = of_get_property(nc,
118 "linux,default-trigger",
119 NULL);
120
121 if (!of_property_read_string(nc, "default-state", &state)) {
122 if (!strcmp(state, "on")) {
123 led->cdev.brightness = LED_FULL;
124 } else if (!strcmp(state, "keep")) {
125 unsigned long val;
126 val = bcm6358_led_read(led->mem + BCM6358_REG_MODE);
127 val &= BIT(led->pin);
128 if ((led->active_low && !val) ||
129 (!led->active_low && val))
130 led->cdev.brightness = LED_FULL;
131 else
132 led->cdev.brightness = LED_OFF;
133 } else {
134 led->cdev.brightness = LED_OFF;
135 }
136 } else {
137 led->cdev.brightness = LED_OFF;
138 }
139
140 bcm6358_led_set(&led->cdev, led->cdev.brightness);
141
142 led->cdev.brightness_set = bcm6358_led_set;
143
144 rc = led_classdev_register(dev, &led->cdev);
145 if (rc < 0)
146 return rc;
147
148 dev_dbg(dev, "registered LED %s\n", led->cdev.name);
149
150 return 0;
151}
152
153static int bcm6358_leds_probe(struct platform_device *pdev)
154{
155 struct device *dev = &pdev->dev;
156 struct device_node *np = pdev->dev.of_node;
157 struct device_node *child;
158 struct resource *mem_r;
159 void __iomem *mem;
160 spinlock_t *lock; /* memory lock */
161 unsigned long val;
162 u32 clk_div;
163
164 mem_r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
165 if (!mem_r)
166 return -EINVAL;
167
168 mem = devm_ioremap_resource(dev, mem_r);
169 if (IS_ERR(mem))
170 return PTR_ERR(mem);
171
172 lock = devm_kzalloc(dev, sizeof(*lock), GFP_KERNEL);
173 if (!lock)
174 return -ENOMEM;
175
176 spin_lock_init(lock);
177
178 val = bcm6358_led_busy(mem);
179 val &= ~(BCM6358_SLED_POLARITY | BCM6358_SLED_CLKDIV_MASK);
180 if (of_property_read_bool(np, "brcm,clk-dat-low"))
181 val |= BCM6358_SLED_POLARITY;
182 of_property_read_u32(np, "brcm,clk-div", &clk_div);
183 switch (clk_div) {
184 case 8:
185 val |= BCM6358_SLED_CLKDIV_8;
186 break;
187 case 4:
188 val |= BCM6358_SLED_CLKDIV_4;
189 break;
190 case 2:
191 val |= BCM6358_SLED_CLKDIV_2;
192 break;
193 default:
194 val |= BCM6358_SLED_CLKDIV_1;
195 break;
196 }
197 bcm6358_led_write(mem + BCM6358_REG_CTRL, val);
198
199 for_each_available_child_of_node(np, child) {
200 int rc;
201 u32 reg;
202
203 if (of_property_read_u32(child, "reg", ®))
204 continue;
205
206 if (reg >= BCM6358_SLED_MAX_COUNT) {
207 dev_err(dev, "invalid LED (%u >= %d)\n", reg,
208 BCM6358_SLED_MAX_COUNT);
209 continue;
210 }
211
212 rc = bcm6358_led(dev, child, reg, mem, lock);
213 if (rc < 0) {
214 of_node_put(child);
215 return rc;
216 }
217 }
218
219 return 0;
220}
221
222static const struct of_device_id bcm6358_leds_of_match[] = {
223 { .compatible = "brcm,bcm6358-leds", },
224 { },
225};
226MODULE_DEVICE_TABLE(of, bcm6358_leds_of_match);
227
228static struct platform_driver bcm6358_leds_driver = {
229 .probe = bcm6358_leds_probe,
230 .driver = {
231 .name = "leds-bcm6358",
232 .of_match_table = bcm6358_leds_of_match,
233 },
234};
235
236module_platform_driver(bcm6358_leds_driver);
237
238MODULE_AUTHOR("Álvaro Fernández Rojas <noltari@gmail.com>");
239MODULE_DESCRIPTION("LED driver for BCM6358 controllers");
240MODULE_LICENSE("GPL v2");
241MODULE_ALIAS("platform:leds-bcm6358");