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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
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34
35
36
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 bcm6358_led *led;
98 const char *state;
99 int rc;
100
101 led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
102 if (!led)
103 return -ENOMEM;
104
105 led->pin = reg;
106 led->mem = mem;
107 led->lock = lock;
108
109 if (of_property_read_bool(nc, "active-low"))
110 led->active_low = true;
111
112 led->cdev.name = of_get_property(nc, "label", NULL) ? : nc->name;
113 led->cdev.default_trigger = of_get_property(nc,
114 "linux,default-trigger",
115 NULL);
116
117 if (!of_property_read_string(nc, "default-state", &state)) {
118 if (!strcmp(state, "on")) {
119 led->cdev.brightness = LED_FULL;
120 } else if (!strcmp(state, "keep")) {
121 unsigned long val;
122 val = bcm6358_led_read(led->mem + BCM6358_REG_MODE);
123 val &= BIT(led->pin);
124 if ((led->active_low && !val) ||
125 (!led->active_low && val))
126 led->cdev.brightness = LED_FULL;
127 else
128 led->cdev.brightness = LED_OFF;
129 } else {
130 led->cdev.brightness = LED_OFF;
131 }
132 } else {
133 led->cdev.brightness = LED_OFF;
134 }
135
136 bcm6358_led_set(&led->cdev, led->cdev.brightness);
137
138 led->cdev.brightness_set = bcm6358_led_set;
139
140 rc = led_classdev_register(dev, &led->cdev);
141 if (rc < 0)
142 return rc;
143
144 dev_dbg(dev, "registered LED %s\n", led->cdev.name);
145
146 return 0;
147}
148
149static int bcm6358_leds_probe(struct platform_device *pdev)
150{
151 struct device *dev = &pdev->dev;
152 struct device_node *np = pdev->dev.of_node;
153 struct device_node *child;
154 void __iomem *mem;
155 spinlock_t *lock;
156 unsigned long val;
157 u32 clk_div;
158
159 mem = devm_platform_ioremap_resource(pdev, 0);
160 if (IS_ERR(mem))
161 return PTR_ERR(mem);
162
163 lock = devm_kzalloc(dev, sizeof(*lock), GFP_KERNEL);
164 if (!lock)
165 return -ENOMEM;
166
167 spin_lock_init(lock);
168
169 val = bcm6358_led_busy(mem);
170 val &= ~(BCM6358_SLED_POLARITY | BCM6358_SLED_CLKDIV_MASK);
171 if (of_property_read_bool(np, "brcm,clk-dat-low"))
172 val |= BCM6358_SLED_POLARITY;
173 of_property_read_u32(np, "brcm,clk-div", &clk_div);
174 switch (clk_div) {
175 case 8:
176 val |= BCM6358_SLED_CLKDIV_8;
177 break;
178 case 4:
179 val |= BCM6358_SLED_CLKDIV_4;
180 break;
181 case 2:
182 val |= BCM6358_SLED_CLKDIV_2;
183 break;
184 default:
185 val |= BCM6358_SLED_CLKDIV_1;
186 break;
187 }
188 bcm6358_led_write(mem + BCM6358_REG_CTRL, val);
189
190 for_each_available_child_of_node(np, child) {
191 int rc;
192 u32 reg;
193
194 if (of_property_read_u32(child, "reg", ®))
195 continue;
196
197 if (reg >= BCM6358_SLED_MAX_COUNT) {
198 dev_err(dev, "invalid LED (%u >= %d)\n", reg,
199 BCM6358_SLED_MAX_COUNT);
200 continue;
201 }
202
203 rc = bcm6358_led(dev, child, reg, mem, lock);
204 if (rc < 0) {
205 of_node_put(child);
206 return rc;
207 }
208 }
209
210 return 0;
211}
212
213static const struct of_device_id bcm6358_leds_of_match[] = {
214 { .compatible = "brcm,bcm6358-leds", },
215 { },
216};
217MODULE_DEVICE_TABLE(of, bcm6358_leds_of_match);
218
219static struct platform_driver bcm6358_leds_driver = {
220 .probe = bcm6358_leds_probe,
221 .driver = {
222 .name = "leds-bcm6358",
223 .of_match_table = bcm6358_leds_of_match,
224 },
225};
226
227module_platform_driver(bcm6358_leds_driver);
228
229MODULE_AUTHOR("Álvaro Fernández Rojas <noltari@gmail.com>");
230MODULE_DESCRIPTION("LED driver for BCM6358 controllers");
231MODULE_LICENSE("GPL v2");
232MODULE_ALIAS("platform:leds-bcm6358");
233
