1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
|
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Driver for BCM6358 memory-mapped LEDs, based on leds-syscon.c
*
* Copyright 2015 Álvaro Fernández Rojas <noltari@gmail.com>
*/
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/leds.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/spinlock.h>
#define BCM6358_REG_MODE 0x0
#define BCM6358_REG_CTRL 0x4
#define BCM6358_SLED_CLKDIV_MASK 3
#define BCM6358_SLED_CLKDIV_1 0
#define BCM6358_SLED_CLKDIV_2 1
#define BCM6358_SLED_CLKDIV_4 2
#define BCM6358_SLED_CLKDIV_8 3
#define BCM6358_SLED_POLARITY BIT(2)
#define BCM6358_SLED_BUSY BIT(3)
#define BCM6358_SLED_MAX_COUNT 32
#define BCM6358_SLED_WAIT 100
/**
* struct bcm6358_led - state container for bcm6358 based LEDs
* @cdev: LED class device for this LED
* @mem: memory resource
* @lock: memory lock
* @pin: LED pin number
* @active_low: LED is active low
*/
struct bcm6358_led {
struct led_classdev cdev;
void __iomem *mem;
spinlock_t *lock;
unsigned long pin;
bool active_low;
};
static void bcm6358_led_write(void __iomem *reg, unsigned long data)
{
#ifdef CONFIG_CPU_BIG_ENDIAN
iowrite32be(data, reg);
#else
writel(data, reg);
#endif
}
static unsigned long bcm6358_led_read(void __iomem *reg)
{
#ifdef CONFIG_CPU_BIG_ENDIAN
return ioread32be(reg);
#else
return readl(reg);
#endif
}
static unsigned long bcm6358_led_busy(void __iomem *mem)
{
unsigned long val;
while ((val = bcm6358_led_read(mem + BCM6358_REG_CTRL)) &
BCM6358_SLED_BUSY)
udelay(BCM6358_SLED_WAIT);
return val;
}
static void bcm6358_led_set(struct led_classdev *led_cdev,
enum led_brightness value)
{
struct bcm6358_led *led =
container_of(led_cdev, struct bcm6358_led, cdev);
unsigned long flags, val;
spin_lock_irqsave(led->lock, flags);
bcm6358_led_busy(led->mem);
val = bcm6358_led_read(led->mem + BCM6358_REG_MODE);
if ((led->active_low && value == LED_OFF) ||
(!led->active_low && value != LED_OFF))
val |= BIT(led->pin);
else
val &= ~(BIT(led->pin));
bcm6358_led_write(led->mem + BCM6358_REG_MODE, val);
spin_unlock_irqrestore(led->lock, flags);
}
static int bcm6358_led(struct device *dev, struct device_node *nc, u32 reg,
void __iomem *mem, spinlock_t *lock)
{
struct bcm6358_led *led;
const char *state;
int rc;
led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
if (!led)
return -ENOMEM;
led->pin = reg;
led->mem = mem;
led->lock = lock;
if (of_property_read_bool(nc, "active-low"))
led->active_low = true;
led->cdev.name = of_get_property(nc, "label", NULL) ? : nc->name;
led->cdev.default_trigger = of_get_property(nc,
"linux,default-trigger",
NULL);
if (!of_property_read_string(nc, "default-state", &state)) {
if (!strcmp(state, "on")) {
led->cdev.brightness = LED_FULL;
} else if (!strcmp(state, "keep")) {
unsigned long val;
val = bcm6358_led_read(led->mem + BCM6358_REG_MODE);
val &= BIT(led->pin);
if ((led->active_low && !val) ||
(!led->active_low && val))
led->cdev.brightness = LED_FULL;
else
led->cdev.brightness = LED_OFF;
} else {
led->cdev.brightness = LED_OFF;
}
} else {
led->cdev.brightness = LED_OFF;
}
bcm6358_led_set(&led->cdev, led->cdev.brightness);
led->cdev.brightness_set = bcm6358_led_set;
rc = led_classdev_register(dev, &led->cdev);
if (rc < 0)
return rc;
dev_dbg(dev, "registered LED %s\n", led->cdev.name);
return 0;
}
static int bcm6358_leds_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *np = pdev->dev.of_node;
struct device_node *child;
void __iomem *mem;
spinlock_t *lock; /* memory lock */
unsigned long val;
u32 clk_div;
mem = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(mem))
return PTR_ERR(mem);
lock = devm_kzalloc(dev, sizeof(*lock), GFP_KERNEL);
if (!lock)
return -ENOMEM;
spin_lock_init(lock);
val = bcm6358_led_busy(mem);
val &= ~(BCM6358_SLED_POLARITY | BCM6358_SLED_CLKDIV_MASK);
if (of_property_read_bool(np, "brcm,clk-dat-low"))
val |= BCM6358_SLED_POLARITY;
of_property_read_u32(np, "brcm,clk-div", &clk_div);
switch (clk_div) {
case 8:
val |= BCM6358_SLED_CLKDIV_8;
break;
case 4:
val |= BCM6358_SLED_CLKDIV_4;
break;
case 2:
val |= BCM6358_SLED_CLKDIV_2;
break;
default:
val |= BCM6358_SLED_CLKDIV_1;
break;
}
bcm6358_led_write(mem + BCM6358_REG_CTRL, val);
for_each_available_child_of_node(np, child) {
int rc;
u32 reg;
if (of_property_read_u32(child, "reg", ®))
continue;
if (reg >= BCM6358_SLED_MAX_COUNT) {
dev_err(dev, "invalid LED (%u >= %d)\n", reg,
BCM6358_SLED_MAX_COUNT);
continue;
}
rc = bcm6358_led(dev, child, reg, mem, lock);
if (rc < 0) {
of_node_put(child);
return rc;
}
}
return 0;
}
static const struct of_device_id bcm6358_leds_of_match[] = {
{ .compatible = "brcm,bcm6358-leds", },
{ },
};
MODULE_DEVICE_TABLE(of, bcm6358_leds_of_match);
static struct platform_driver bcm6358_leds_driver = {
.probe = bcm6358_leds_probe,
.driver = {
.name = "leds-bcm6358",
.of_match_table = bcm6358_leds_of_match,
},
};
module_platform_driver(bcm6358_leds_driver);
MODULE_AUTHOR("Álvaro Fernández Rojas <noltari@gmail.com>");
MODULE_DESCRIPTION("LED driver for BCM6358 controllers");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:leds-bcm6358");
|
