Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target...
[firefly-linux-kernel-4.4.55.git] / drivers / leds / leds-bcm6328.c
1 /*
2  * Driver for BCM6328 memory-mapped LEDs, based on leds-syscon.c
3  *
4  * Copyright 2015 Álvaro Fernández Rojas <noltari@gmail.com>
5  * Copyright 2015 Jonas Gorski <jogo@openwrt.org>
6  *
7  * This program is free software; you can redistribute  it and/or modify it
8  * under  the terms of  the GNU General  Public License as published by the
9  * Free Software Foundation;  either version 2 of the  License, or (at your
10  * option) any later version.
11  */
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 BCM6328_REG_INIT                0x00
20 #define BCM6328_REG_MODE_HI             0x04
21 #define BCM6328_REG_MODE_LO             0x08
22 #define BCM6328_REG_HWDIS               0x0c
23 #define BCM6328_REG_STROBE              0x10
24 #define BCM6328_REG_LNKACTSEL_HI        0x14
25 #define BCM6328_REG_LNKACTSEL_LO        0x18
26 #define BCM6328_REG_RBACK               0x1c
27 #define BCM6328_REG_SERMUX              0x20
28
29 #define BCM6328_LED_MAX_COUNT           24
30 #define BCM6328_LED_DEF_DELAY           500
31 #define BCM6328_LED_INTERVAL_MS         20
32
33 #define BCM6328_LED_INTV_MASK           0x3f
34 #define BCM6328_LED_FAST_INTV_SHIFT     6
35 #define BCM6328_LED_FAST_INTV_MASK      (BCM6328_LED_INTV_MASK << \
36                                          BCM6328_LED_FAST_INTV_SHIFT)
37 #define BCM6328_SERIAL_LED_EN           BIT(12)
38 #define BCM6328_SERIAL_LED_MUX          BIT(13)
39 #define BCM6328_SERIAL_LED_CLK_NPOL     BIT(14)
40 #define BCM6328_SERIAL_LED_DATA_PPOL    BIT(15)
41 #define BCM6328_SERIAL_LED_SHIFT_DIR    BIT(16)
42 #define BCM6328_LED_SHIFT_TEST          BIT(30)
43 #define BCM6328_LED_TEST                BIT(31)
44 #define BCM6328_INIT_MASK               (BCM6328_SERIAL_LED_EN | \
45                                          BCM6328_SERIAL_LED_MUX  | \
46                                          BCM6328_SERIAL_LED_CLK_NPOL | \
47                                          BCM6328_SERIAL_LED_DATA_PPOL | \
48                                          BCM6328_SERIAL_LED_SHIFT_DIR)
49
50 #define BCM6328_LED_MODE_MASK           3
51 #define BCM6328_LED_MODE_OFF            0
52 #define BCM6328_LED_MODE_FAST           1
53 #define BCM6328_LED_MODE_BLINK          2
54 #define BCM6328_LED_MODE_ON             3
55 #define BCM6328_LED_SHIFT(X)            ((X) << 1)
56
57 /**
58  * struct bcm6328_led - state container for bcm6328 based LEDs
59  * @cdev: LED class device for this LED
60  * @mem: memory resource
61  * @lock: memory lock
62  * @pin: LED pin number
63  * @blink_leds: blinking LEDs
64  * @blink_delay: blinking delay
65  * @active_low: LED is active low
66  */
67 struct bcm6328_led {
68         struct led_classdev cdev;
69         void __iomem *mem;
70         spinlock_t *lock;
71         unsigned long pin;
72         unsigned long *blink_leds;
73         unsigned long *blink_delay;
74         bool active_low;
75 };
76
77 static void bcm6328_led_write(void __iomem *reg, unsigned long data)
78 {
79         iowrite32be(data, reg);
80 }
81
82 static unsigned long bcm6328_led_read(void __iomem *reg)
83 {
84         return ioread32be(reg);
85 }
86
87 /**
88  * LEDMode 64 bits / 24 LEDs
89  * bits [31:0] -> LEDs 8-23
90  * bits [47:32] -> LEDs 0-7
91  * bits [63:48] -> unused
92  */
93 static unsigned long bcm6328_pin2shift(unsigned long pin)
94 {
95         if (pin < 8)
96                 return pin + 16; /* LEDs 0-7 (bits 47:32) */
97         else
98                 return pin - 8; /* LEDs 8-23 (bits 31:0) */
99 }
100
101 static void bcm6328_led_mode(struct bcm6328_led *led, unsigned long value)
102 {
103         void __iomem *mode;
104         unsigned long val, shift;
105
106         shift = bcm6328_pin2shift(led->pin);
107         if (shift / 16)
108                 mode = led->mem + BCM6328_REG_MODE_HI;
109         else
110                 mode = led->mem + BCM6328_REG_MODE_LO;
111
112         val = bcm6328_led_read(mode);
113         val &= ~(BCM6328_LED_MODE_MASK << BCM6328_LED_SHIFT(shift % 16));
114         val |= (value << BCM6328_LED_SHIFT(shift % 16));
115         bcm6328_led_write(mode, val);
116 }
117
118 static void bcm6328_led_set(struct led_classdev *led_cdev,
119                             enum led_brightness value)
120 {
121         struct bcm6328_led *led =
122                 container_of(led_cdev, struct bcm6328_led, cdev);
123         unsigned long flags;
124
125         spin_lock_irqsave(led->lock, flags);
126         *(led->blink_leds) &= ~BIT(led->pin);
127         if ((led->active_low && value == LED_OFF) ||
128             (!led->active_low && value != LED_OFF))
129                 bcm6328_led_mode(led, BCM6328_LED_MODE_OFF);
130         else
131                 bcm6328_led_mode(led, BCM6328_LED_MODE_ON);
132         spin_unlock_irqrestore(led->lock, flags);
133 }
134
135 static int bcm6328_blink_set(struct led_classdev *led_cdev,
136                              unsigned long *delay_on, unsigned long *delay_off)
137 {
138         struct bcm6328_led *led =
139                 container_of(led_cdev, struct bcm6328_led, cdev);
140         unsigned long delay, flags;
141
142         if (!*delay_on)
143                 *delay_on = BCM6328_LED_DEF_DELAY;
144         if (!*delay_off)
145                 *delay_off = BCM6328_LED_DEF_DELAY;
146
147         if (*delay_on != *delay_off) {
148                 dev_dbg(led_cdev->dev,
149                         "fallback to soft blinking (delay_on != delay_off)\n");
150                 return -EINVAL;
151         }
152
153         delay = *delay_on / BCM6328_LED_INTERVAL_MS;
154         if (delay == 0)
155                 delay = 1;
156         else if (delay > BCM6328_LED_INTV_MASK) {
157                 dev_dbg(led_cdev->dev,
158                         "fallback to soft blinking (delay > %ums)\n",
159                         BCM6328_LED_INTV_MASK * BCM6328_LED_INTERVAL_MS);
160                 return -EINVAL;
161         }
162
163         spin_lock_irqsave(led->lock, flags);
164         if (*(led->blink_leds) == 0 ||
165             *(led->blink_leds) == BIT(led->pin) ||
166             *(led->blink_delay) == delay) {
167                 unsigned long val;
168
169                 *(led->blink_leds) |= BIT(led->pin);
170                 *(led->blink_delay) = delay;
171
172                 val = bcm6328_led_read(led->mem + BCM6328_REG_INIT);
173                 val &= ~BCM6328_LED_FAST_INTV_MASK;
174                 val |= (delay << BCM6328_LED_FAST_INTV_SHIFT);
175                 bcm6328_led_write(led->mem + BCM6328_REG_INIT, val);
176
177                 bcm6328_led_mode(led, BCM6328_LED_MODE_BLINK);
178
179                 spin_unlock_irqrestore(led->lock, flags);
180         } else {
181                 spin_unlock_irqrestore(led->lock, flags);
182                 dev_dbg(led_cdev->dev,
183                         "fallback to soft blinking (delay already set)\n");
184                 return -EINVAL;
185         }
186
187         return 0;
188 }
189
190 static int bcm6328_hwled(struct device *dev, struct device_node *nc, u32 reg,
191                          void __iomem *mem, spinlock_t *lock)
192 {
193         int i, cnt;
194         unsigned long flags, val;
195
196         spin_lock_irqsave(lock, flags);
197         val = bcm6328_led_read(mem + BCM6328_REG_HWDIS);
198         val &= ~BIT(reg);
199         bcm6328_led_write(mem + BCM6328_REG_HWDIS, val);
200         spin_unlock_irqrestore(lock, flags);
201
202         /* Only LEDs 0-7 can be activity/link controlled */
203         if (reg >= 8)
204                 return 0;
205
206         cnt = of_property_count_elems_of_size(nc, "brcm,link-signal-sources",
207                                               sizeof(u32));
208         for (i = 0; i < cnt; i++) {
209                 u32 sel;
210                 void __iomem *addr;
211
212                 if (reg < 4)
213                         addr = mem + BCM6328_REG_LNKACTSEL_LO;
214                 else
215                         addr = mem + BCM6328_REG_LNKACTSEL_HI;
216
217                 of_property_read_u32_index(nc, "brcm,link-signal-sources", i,
218                                            &sel);
219
220                 if (reg / 4 != sel / 4) {
221                         dev_warn(dev, "invalid link signal source\n");
222                         continue;
223                 }
224
225                 spin_lock_irqsave(lock, flags);
226                 val = bcm6328_led_read(addr);
227                 val |= (BIT(reg) << (((sel % 4) * 4) + 16));
228                 bcm6328_led_write(addr, val);
229                 spin_unlock_irqrestore(lock, flags);
230         }
231
232         cnt = of_property_count_elems_of_size(nc,
233                                               "brcm,activity-signal-sources",
234                                               sizeof(u32));
235         for (i = 0; i < cnt; i++) {
236                 u32 sel;
237                 void __iomem *addr;
238
239                 if (reg < 4)
240                         addr = mem + BCM6328_REG_LNKACTSEL_LO;
241                 else
242                         addr = mem + BCM6328_REG_LNKACTSEL_HI;
243
244                 of_property_read_u32_index(nc, "brcm,activity-signal-sources",
245                                            i, &sel);
246
247                 if (reg / 4 != sel / 4) {
248                         dev_warn(dev, "invalid activity signal source\n");
249                         continue;
250                 }
251
252                 spin_lock_irqsave(lock, flags);
253                 val = bcm6328_led_read(addr);
254                 val |= (BIT(reg) << ((sel % 4) * 4));
255                 bcm6328_led_write(addr, val);
256                 spin_unlock_irqrestore(lock, flags);
257         }
258
259         return 0;
260 }
261
262 static int bcm6328_led(struct device *dev, struct device_node *nc, u32 reg,
263                        void __iomem *mem, spinlock_t *lock,
264                        unsigned long *blink_leds, unsigned long *blink_delay)
265 {
266         struct bcm6328_led *led;
267         unsigned long flags;
268         const char *state;
269         int rc;
270
271         led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
272         if (!led)
273                 return -ENOMEM;
274
275         led->pin = reg;
276         led->mem = mem;
277         led->lock = lock;
278         led->blink_leds = blink_leds;
279         led->blink_delay = blink_delay;
280
281         if (of_property_read_bool(nc, "active-low"))
282                 led->active_low = true;
283
284         led->cdev.name = of_get_property(nc, "label", NULL) ? : nc->name;
285         led->cdev.default_trigger = of_get_property(nc,
286                                                     "linux,default-trigger",
287                                                     NULL);
288
289         spin_lock_irqsave(lock, flags);
290         if (!of_property_read_string(nc, "default-state", &state)) {
291                 if (!strcmp(state, "on")) {
292                         led->cdev.brightness = LED_FULL;
293                 } else if (!strcmp(state, "keep")) {
294                         void __iomem *mode;
295                         unsigned long val, shift;
296
297                         shift = bcm6328_pin2shift(led->pin);
298                         if (shift / 16)
299                                 mode = mem + BCM6328_REG_MODE_HI;
300                         else
301                                 mode = mem + BCM6328_REG_MODE_LO;
302
303                         val = bcm6328_led_read(mode) >>
304                               BCM6328_LED_SHIFT(shift % 16);
305                         val &= BCM6328_LED_MODE_MASK;
306                         if ((led->active_low && val == BCM6328_LED_MODE_ON) ||
307                             (!led->active_low && val == BCM6328_LED_MODE_OFF))
308                                 led->cdev.brightness = LED_FULL;
309                         else
310                                 led->cdev.brightness = LED_OFF;
311                 } else {
312                         led->cdev.brightness = LED_OFF;
313                 }
314         } else {
315                 led->cdev.brightness = LED_OFF;
316         }
317
318         if ((led->active_low && led->cdev.brightness == LED_FULL) ||
319             (!led->active_low && led->cdev.brightness == LED_OFF))
320                 bcm6328_led_mode(led, BCM6328_LED_MODE_ON);
321         else
322                 bcm6328_led_mode(led, BCM6328_LED_MODE_OFF);
323         spin_unlock_irqrestore(lock, flags);
324
325         led->cdev.brightness_set = bcm6328_led_set;
326         led->cdev.blink_set = bcm6328_blink_set;
327
328         rc = led_classdev_register(dev, &led->cdev);
329         if (rc < 0)
330                 return rc;
331
332         dev_dbg(dev, "registered LED %s\n", led->cdev.name);
333
334         return 0;
335 }
336
337 static int bcm6328_leds_probe(struct platform_device *pdev)
338 {
339         struct device *dev = &pdev->dev;
340         struct device_node *np = pdev->dev.of_node;
341         struct device_node *child;
342         struct resource *mem_r;
343         void __iomem *mem;
344         spinlock_t *lock;
345         unsigned long val, *blink_leds, *blink_delay;
346
347         mem_r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
348         if (!mem_r)
349                 return -EINVAL;
350
351         mem = devm_ioremap_resource(dev, mem_r);
352         if (IS_ERR(mem))
353                 return PTR_ERR(mem);
354
355         lock = devm_kzalloc(dev, sizeof(*lock), GFP_KERNEL);
356         if (!lock)
357                 return -ENOMEM;
358
359         blink_leds = devm_kzalloc(dev, sizeof(*blink_leds), GFP_KERNEL);
360         if (!blink_leds)
361                 return -ENOMEM;
362
363         blink_delay = devm_kzalloc(dev, sizeof(*blink_delay), GFP_KERNEL);
364         if (!blink_delay)
365                 return -ENOMEM;
366
367         spin_lock_init(lock);
368
369         bcm6328_led_write(mem + BCM6328_REG_HWDIS, ~0);
370         bcm6328_led_write(mem + BCM6328_REG_LNKACTSEL_HI, 0);
371         bcm6328_led_write(mem + BCM6328_REG_LNKACTSEL_LO, 0);
372
373         val = bcm6328_led_read(mem + BCM6328_REG_INIT);
374         val &= ~(BCM6328_INIT_MASK);
375         if (of_property_read_bool(np, "brcm,serial-leds"))
376                 val |= BCM6328_SERIAL_LED_EN;
377         if (of_property_read_bool(np, "brcm,serial-mux"))
378                 val |= BCM6328_SERIAL_LED_MUX;
379         if (of_property_read_bool(np, "brcm,serial-clk-low"))
380                 val |= BCM6328_SERIAL_LED_CLK_NPOL;
381         if (!of_property_read_bool(np, "brcm,serial-dat-low"))
382                 val |= BCM6328_SERIAL_LED_DATA_PPOL;
383         if (!of_property_read_bool(np, "brcm,serial-shift-inv"))
384                 val |= BCM6328_SERIAL_LED_SHIFT_DIR;
385         bcm6328_led_write(mem + BCM6328_REG_INIT, val);
386
387         for_each_available_child_of_node(np, child) {
388                 int rc;
389                 u32 reg;
390
391                 if (of_property_read_u32(child, "reg", &reg))
392                         continue;
393
394                 if (reg >= BCM6328_LED_MAX_COUNT) {
395                         dev_err(dev, "invalid LED (%u >= %d)\n", reg,
396                                 BCM6328_LED_MAX_COUNT);
397                         continue;
398                 }
399
400                 if (of_property_read_bool(child, "brcm,hardware-controlled"))
401                         rc = bcm6328_hwled(dev, child, reg, mem, lock);
402                 else
403                         rc = bcm6328_led(dev, child, reg, mem, lock,
404                                          blink_leds, blink_delay);
405
406                 if (rc < 0) {
407                         of_node_put(child);
408                         return rc;
409                 }
410         }
411
412         return 0;
413 }
414
415 static const struct of_device_id bcm6328_leds_of_match[] = {
416         { .compatible = "brcm,bcm6328-leds", },
417         { },
418 };
419 MODULE_DEVICE_TABLE(of, bcm6328_leds_of_match);
420
421 static struct platform_driver bcm6328_leds_driver = {
422         .probe = bcm6328_leds_probe,
423         .driver = {
424                 .name = "leds-bcm6328",
425                 .of_match_table = bcm6328_leds_of_match,
426         },
427 };
428
429 module_platform_driver(bcm6328_leds_driver);
430
431 MODULE_AUTHOR("Álvaro Fernández Rojas <noltari@gmail.com>");
432 MODULE_AUTHOR("Jonas Gorski <jogo@openwrt.org>");
433 MODULE_DESCRIPTION("LED driver for BCM6328 controllers");
434 MODULE_LICENSE("GPL v2");
435 MODULE_ALIAS("platform:leds-bcm6328");