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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
36
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38
39
40
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;
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");
242
