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f46e9203 NC |
1 | /* |
2 | * Copyright 2007-2008 Extreme Engineering Solutions, Inc. | |
3 | * | |
4 | * Author: Nate Case <ncase@xes-inc.com> | |
5 | * | |
6 | * This file is subject to the terms and conditions of version 2 of | |
7 | * the GNU General Public License. See the file COPYING in the main | |
8 | * directory of this archive for more details. | |
9 | * | |
10 | * LED driver for various PCA955x I2C LED drivers | |
11 | * | |
12 | * Supported devices: | |
13 | * | |
14 | * Device Description 7-bit slave address | |
15 | * ------ ----------- ------------------- | |
16 | * PCA9550 2-bit driver 0x60 .. 0x61 | |
17 | * PCA9551 8-bit driver 0x60 .. 0x67 | |
18 | * PCA9552 16-bit driver 0x60 .. 0x67 | |
19 | * PCA9553/01 4-bit driver 0x62 | |
20 | * PCA9553/02 4-bit driver 0x63 | |
21 | * | |
22 | * Philips PCA955x LED driver chips follow a register map as shown below: | |
23 | * | |
24 | * Control Register Description | |
25 | * ---------------- ----------- | |
26 | * 0x0 Input register 0 | |
27 | * .. | |
28 | * NUM_INPUT_REGS - 1 Last Input register X | |
29 | * | |
30 | * NUM_INPUT_REGS Frequency prescaler 0 | |
31 | * NUM_INPUT_REGS + 1 PWM register 0 | |
32 | * NUM_INPUT_REGS + 2 Frequency prescaler 1 | |
33 | * NUM_INPUT_REGS + 3 PWM register 1 | |
34 | * | |
35 | * NUM_INPUT_REGS + 4 LED selector 0 | |
36 | * NUM_INPUT_REGS + 4 | |
37 | * + NUM_LED_REGS - 1 Last LED selector | |
38 | * | |
39 | * where NUM_INPUT_REGS and NUM_LED_REGS vary depending on how many | |
40 | * bits the chip supports. | |
41 | */ | |
42 | ||
44b3e31d | 43 | #include <linux/acpi.h> |
f46e9203 NC |
44 | #include <linux/module.h> |
45 | #include <linux/delay.h> | |
46 | #include <linux/string.h> | |
47 | #include <linux/ctype.h> | |
48 | #include <linux/leds.h> | |
49 | #include <linux/err.h> | |
50 | #include <linux/i2c.h> | |
5a0e3ad6 | 51 | #include <linux/slab.h> |
f46e9203 NC |
52 | |
53 | /* LED select registers determine the source that drives LED outputs */ | |
54 | #define PCA955X_LS_LED_ON 0x0 /* Output LOW */ | |
55 | #define PCA955X_LS_LED_OFF 0x1 /* Output HI-Z */ | |
56 | #define PCA955X_LS_BLINK0 0x2 /* Blink at PWM0 rate */ | |
57 | #define PCA955X_LS_BLINK1 0x3 /* Blink at PWM1 rate */ | |
58 | ||
59 | enum pca955x_type { | |
60 | pca9550, | |
61 | pca9551, | |
62 | pca9552, | |
63 | pca9553, | |
64 | }; | |
65 | ||
66 | struct pca955x_chipdef { | |
67 | int bits; | |
68 | u8 slv_addr; /* 7-bit slave address mask */ | |
69 | int slv_addr_shift; /* Number of bits to ignore */ | |
70 | }; | |
71 | ||
72 | static struct pca955x_chipdef pca955x_chipdefs[] = { | |
73 | [pca9550] = { | |
74 | .bits = 2, | |
75 | .slv_addr = /* 110000x */ 0x60, | |
76 | .slv_addr_shift = 1, | |
77 | }, | |
78 | [pca9551] = { | |
79 | .bits = 8, | |
80 | .slv_addr = /* 1100xxx */ 0x60, | |
81 | .slv_addr_shift = 3, | |
82 | }, | |
83 | [pca9552] = { | |
84 | .bits = 16, | |
85 | .slv_addr = /* 1100xxx */ 0x60, | |
86 | .slv_addr_shift = 3, | |
87 | }, | |
88 | [pca9553] = { | |
89 | .bits = 4, | |
90 | .slv_addr = /* 110001x */ 0x62, | |
91 | .slv_addr_shift = 1, | |
92 | }, | |
93 | }; | |
94 | ||
95 | static const struct i2c_device_id pca955x_id[] = { | |
96 | { "pca9550", pca9550 }, | |
97 | { "pca9551", pca9551 }, | |
98 | { "pca9552", pca9552 }, | |
99 | { "pca9553", pca9553 }, | |
100 | { } | |
101 | }; | |
102 | MODULE_DEVICE_TABLE(i2c, pca955x_id); | |
103 | ||
44b3e31d TH |
104 | static const struct acpi_device_id pca955x_acpi_ids[] = { |
105 | { "PCA9550", pca9550 }, | |
106 | { "PCA9551", pca9551 }, | |
107 | { "PCA9552", pca9552 }, | |
108 | { "PCA9553", pca9553 }, | |
109 | { } | |
110 | }; | |
111 | MODULE_DEVICE_TABLE(acpi, pca955x_acpi_ids); | |
112 | ||
e7e11d8b AS |
113 | struct pca955x { |
114 | struct mutex lock; | |
115 | struct pca955x_led *leds; | |
f46e9203 NC |
116 | struct pca955x_chipdef *chipdef; |
117 | struct i2c_client *client; | |
e7e11d8b AS |
118 | }; |
119 | ||
120 | struct pca955x_led { | |
121 | struct pca955x *pca955x; | |
f46e9203 NC |
122 | struct led_classdev led_cdev; |
123 | int led_num; /* 0 .. 15 potentially */ | |
124 | char name[32]; | |
125 | }; | |
126 | ||
127 | /* 8 bits per input register */ | |
128 | static inline int pca95xx_num_input_regs(int bits) | |
129 | { | |
130 | return (bits + 7) / 8; | |
131 | } | |
132 | ||
133 | /* 4 bits per LED selector register */ | |
134 | static inline int pca95xx_num_led_regs(int bits) | |
135 | { | |
136 | return (bits + 3) / 4; | |
137 | } | |
138 | ||
139 | /* | |
140 | * Return an LED selector register value based on an existing one, with | |
141 | * the appropriate 2-bit state value set for the given LED number (0-3). | |
142 | */ | |
143 | static inline u8 pca955x_ledsel(u8 oldval, int led_num, int state) | |
144 | { | |
145 | return (oldval & (~(0x3 << (led_num << 1)))) | | |
146 | ((state & 0x3) << (led_num << 1)); | |
147 | } | |
148 | ||
149 | /* | |
150 | * Write to frequency prescaler register, used to program the | |
151 | * period of the PWM output. period = (PSCx + 1) / 38 | |
152 | */ | |
153 | static void pca955x_write_psc(struct i2c_client *client, int n, u8 val) | |
154 | { | |
e7e11d8b | 155 | struct pca955x *pca955x = i2c_get_clientdata(client); |
f46e9203 NC |
156 | |
157 | i2c_smbus_write_byte_data(client, | |
158 | pca95xx_num_input_regs(pca955x->chipdef->bits) + 2*n, | |
159 | val); | |
160 | } | |
161 | ||
162 | /* | |
163 | * Write to PWM register, which determines the duty cycle of the | |
164 | * output. LED is OFF when the count is less than the value of this | |
165 | * register, and ON when it is greater. If PWMx == 0, LED is always OFF. | |
166 | * | |
167 | * Duty cycle is (256 - PWMx) / 256 | |
168 | */ | |
169 | static void pca955x_write_pwm(struct i2c_client *client, int n, u8 val) | |
170 | { | |
e7e11d8b | 171 | struct pca955x *pca955x = i2c_get_clientdata(client); |
f46e9203 NC |
172 | |
173 | i2c_smbus_write_byte_data(client, | |
174 | pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + 2*n, | |
175 | val); | |
176 | } | |
177 | ||
178 | /* | |
179 | * Write to LED selector register, which determines the source that | |
180 | * drives the LED output. | |
181 | */ | |
182 | static void pca955x_write_ls(struct i2c_client *client, int n, u8 val) | |
183 | { | |
e7e11d8b | 184 | struct pca955x *pca955x = i2c_get_clientdata(client); |
f46e9203 NC |
185 | |
186 | i2c_smbus_write_byte_data(client, | |
187 | pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n, | |
188 | val); | |
189 | } | |
190 | ||
191 | /* | |
192 | * Read the LED selector register, which determines the source that | |
193 | * drives the LED output. | |
194 | */ | |
195 | static u8 pca955x_read_ls(struct i2c_client *client, int n) | |
196 | { | |
e7e11d8b | 197 | struct pca955x *pca955x = i2c_get_clientdata(client); |
f46e9203 NC |
198 | |
199 | return (u8) i2c_smbus_read_byte_data(client, | |
200 | pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n); | |
201 | } | |
202 | ||
c3482b82 AL |
203 | static int pca955x_led_set(struct led_classdev *led_cdev, |
204 | enum led_brightness value) | |
f46e9203 | 205 | { |
e7e11d8b AS |
206 | struct pca955x_led *pca955x_led; |
207 | struct pca955x *pca955x; | |
f46e9203 NC |
208 | u8 ls; |
209 | int chip_ls; /* which LSx to use (0-3 potentially) */ | |
210 | int ls_led; /* which set of bits within LSx to use (0-3) */ | |
211 | ||
c3482b82 | 212 | pca955x_led = container_of(led_cdev, struct pca955x_led, led_cdev); |
e7e11d8b AS |
213 | pca955x = pca955x_led->pca955x; |
214 | ||
215 | chip_ls = pca955x_led->led_num / 4; | |
216 | ls_led = pca955x_led->led_num % 4; | |
217 | ||
218 | mutex_lock(&pca955x->lock); | |
f46e9203 NC |
219 | |
220 | ls = pca955x_read_ls(pca955x->client, chip_ls); | |
221 | ||
c3482b82 | 222 | switch (value) { |
f46e9203 NC |
223 | case LED_FULL: |
224 | ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_ON); | |
225 | break; | |
226 | case LED_OFF: | |
227 | ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_OFF); | |
228 | break; | |
229 | case LED_HALF: | |
230 | ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK0); | |
231 | break; | |
232 | default: | |
233 | /* | |
234 | * Use PWM1 for all other values. This has the unwanted | |
235 | * side effect of making all LEDs on the chip share the | |
236 | * same brightness level if set to a value other than | |
237 | * OFF, HALF, or FULL. But, this is probably better than | |
238 | * just turning off for all other values. | |
239 | */ | |
e7e11d8b | 240 | pca955x_write_pwm(pca955x->client, 1, |
c3482b82 | 241 | 255 - value); |
f46e9203 NC |
242 | ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK1); |
243 | break; | |
244 | } | |
245 | ||
246 | pca955x_write_ls(pca955x->client, chip_ls, ls); | |
e7e11d8b AS |
247 | |
248 | mutex_unlock(&pca955x->lock); | |
f46e9203 | 249 | |
c3482b82 | 250 | return 0; |
f46e9203 NC |
251 | } |
252 | ||
98ea1ea2 | 253 | static int pca955x_probe(struct i2c_client *client, |
f46e9203 NC |
254 | const struct i2c_device_id *id) |
255 | { | |
e7e11d8b AS |
256 | struct pca955x *pca955x; |
257 | struct pca955x_led *pca955x_led; | |
f46e9203 NC |
258 | struct pca955x_chipdef *chip; |
259 | struct i2c_adapter *adapter; | |
260 | struct led_platform_data *pdata; | |
95bf14bf | 261 | int i, err; |
f46e9203 | 262 | |
44b3e31d TH |
263 | if (id) { |
264 | chip = &pca955x_chipdefs[id->driver_data]; | |
265 | } else { | |
266 | const struct acpi_device_id *acpi_id; | |
267 | ||
268 | acpi_id = acpi_match_device(pca955x_acpi_ids, &client->dev); | |
269 | if (!acpi_id) | |
270 | return -ENODEV; | |
271 | chip = &pca955x_chipdefs[acpi_id->driver_data]; | |
272 | } | |
f46e9203 | 273 | adapter = to_i2c_adapter(client->dev.parent); |
87aae1ea | 274 | pdata = dev_get_platdata(&client->dev); |
f46e9203 NC |
275 | |
276 | /* Make sure the slave address / chip type combo given is possible */ | |
277 | if ((client->addr & ~((1 << chip->slv_addr_shift) - 1)) != | |
278 | chip->slv_addr) { | |
279 | dev_err(&client->dev, "invalid slave address %02x\n", | |
280 | client->addr); | |
281 | return -ENODEV; | |
282 | } | |
283 | ||
b40b0c17 | 284 | dev_info(&client->dev, "leds-pca955x: Using %s %d-bit LED driver at " |
f46e9203 | 285 | "slave address 0x%02x\n", |
44b3e31d | 286 | client->name, chip->bits, client->addr); |
f46e9203 NC |
287 | |
288 | if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) | |
289 | return -EIO; | |
290 | ||
291 | if (pdata) { | |
292 | if (pdata->num_leds != chip->bits) { | |
293 | dev_err(&client->dev, "board info claims %d LEDs" | |
294 | " on a %d-bit chip\n", | |
295 | pdata->num_leds, chip->bits); | |
296 | return -ENODEV; | |
297 | } | |
298 | } | |
299 | ||
73759f6a | 300 | pca955x = devm_kzalloc(&client->dev, sizeof(*pca955x), GFP_KERNEL); |
95bf14bf SW |
301 | if (!pca955x) |
302 | return -ENOMEM; | |
303 | ||
73759f6a BW |
304 | pca955x->leds = devm_kzalloc(&client->dev, |
305 | sizeof(*pca955x_led) * chip->bits, GFP_KERNEL); | |
306 | if (!pca955x->leds) | |
307 | return -ENOMEM; | |
e7e11d8b | 308 | |
95bf14bf SW |
309 | i2c_set_clientdata(client, pca955x); |
310 | ||
e7e11d8b AS |
311 | mutex_init(&pca955x->lock); |
312 | pca955x->client = client; | |
313 | pca955x->chipdef = chip; | |
314 | ||
f46e9203 | 315 | for (i = 0; i < chip->bits; i++) { |
e7e11d8b AS |
316 | pca955x_led = &pca955x->leds[i]; |
317 | pca955x_led->led_num = i; | |
318 | pca955x_led->pca955x = pca955x; | |
f46e9203 | 319 | |
f46e9203 NC |
320 | /* Platform data can specify LED names and default triggers */ |
321 | if (pdata) { | |
322 | if (pdata->leds[i].name) | |
e7e11d8b AS |
323 | snprintf(pca955x_led->name, |
324 | sizeof(pca955x_led->name), "pca955x:%s", | |
325 | pdata->leds[i].name); | |
f46e9203 | 326 | if (pdata->leds[i].default_trigger) |
e7e11d8b | 327 | pca955x_led->led_cdev.default_trigger = |
f46e9203 NC |
328 | pdata->leds[i].default_trigger; |
329 | } else { | |
e7e11d8b | 330 | snprintf(pca955x_led->name, sizeof(pca955x_led->name), |
95bf14bf | 331 | "pca955x:%d", i); |
f46e9203 | 332 | } |
f46e9203 | 333 | |
e7e11d8b | 334 | pca955x_led->led_cdev.name = pca955x_led->name; |
c3482b82 | 335 | pca955x_led->led_cdev.brightness_set_blocking = pca955x_led_set; |
f46e9203 | 336 | |
e7e11d8b AS |
337 | err = led_classdev_register(&client->dev, |
338 | &pca955x_led->led_cdev); | |
95bf14bf SW |
339 | if (err < 0) |
340 | goto exit; | |
f46e9203 NC |
341 | } |
342 | ||
343 | /* Turn off LEDs */ | |
344 | for (i = 0; i < pca95xx_num_led_regs(chip->bits); i++) | |
345 | pca955x_write_ls(client, i, 0x55); | |
346 | ||
347 | /* PWM0 is used for half brightness or 50% duty cycle */ | |
348 | pca955x_write_pwm(client, 0, 255-LED_HALF); | |
349 | ||
350 | /* PWM1 is used for variable brightness, default to OFF */ | |
351 | pca955x_write_pwm(client, 1, 0); | |
352 | ||
353 | /* Set to fast frequency so we do not see flashing */ | |
354 | pca955x_write_psc(client, 0, 0); | |
355 | pca955x_write_psc(client, 1, 0); | |
356 | ||
357 | return 0; | |
95bf14bf | 358 | |
f46e9203 | 359 | exit: |
c3482b82 | 360 | while (i--) |
e7e11d8b | 361 | led_classdev_unregister(&pca955x->leds[i].led_cdev); |
95bf14bf | 362 | |
f46e9203 NC |
363 | return err; |
364 | } | |
365 | ||
678e8a6b | 366 | static int pca955x_remove(struct i2c_client *client) |
f46e9203 | 367 | { |
e7e11d8b | 368 | struct pca955x *pca955x = i2c_get_clientdata(client); |
f46e9203 NC |
369 | int i; |
370 | ||
c3482b82 | 371 | for (i = 0; i < pca955x->chipdef->bits; i++) |
e7e11d8b | 372 | led_classdev_unregister(&pca955x->leds[i].led_cdev); |
f46e9203 NC |
373 | |
374 | return 0; | |
375 | } | |
376 | ||
377 | static struct i2c_driver pca955x_driver = { | |
378 | .driver = { | |
379 | .name = "leds-pca955x", | |
44b3e31d | 380 | .acpi_match_table = ACPI_PTR(pca955x_acpi_ids), |
f46e9203 NC |
381 | }, |
382 | .probe = pca955x_probe, | |
df07cf81 | 383 | .remove = pca955x_remove, |
f46e9203 NC |
384 | .id_table = pca955x_id, |
385 | }; | |
386 | ||
09a0d183 | 387 | module_i2c_driver(pca955x_driver); |
f46e9203 NC |
388 | |
389 | MODULE_AUTHOR("Nate Case <ncase@xes-inc.com>"); | |
390 | MODULE_DESCRIPTION("PCA955x LED driver"); | |
391 | MODULE_LICENSE("GPL v2"); |