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