Root/drivers/leds/leds-pca9532.c

1/*
2 * pca9532.c - 16-bit Led dimmer
3 *
4 * Copyright (C) 2011 Jan Weitzel
5 * Copyright (C) 2008 Riku Voipio
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; version 2 of the License.
10 *
11 * Datasheet: http://www.nxp.com/documents/data_sheet/PCA9532.pdf
12 *
13 */
14
15#include <linux/module.h>
16#include <linux/i2c.h>
17#include <linux/slab.h>
18#include <linux/leds.h>
19#include <linux/input.h>
20#include <linux/mutex.h>
21#include <linux/workqueue.h>
22#include <linux/leds-pca9532.h>
23#include <linux/gpio.h>
24
25/* m = num_leds*/
26#define PCA9532_REG_INPUT(i) ((i) >> 3)
27#define PCA9532_REG_OFFSET(m) ((m) >> 4)
28#define PCA9532_REG_PSC(m, i) (PCA9532_REG_OFFSET(m) + 0x1 + (i) * 2)
29#define PCA9532_REG_PWM(m, i) (PCA9532_REG_OFFSET(m) + 0x2 + (i) * 2)
30#define LED_REG(m, led) (PCA9532_REG_OFFSET(m) + 0x5 + (led >> 2))
31#define LED_NUM(led) (led & 0x3)
32
33#define ldev_to_led(c) container_of(c, struct pca9532_led, ldev)
34
35struct pca9532_chip_info {
36    u8 num_leds;
37};
38
39struct pca9532_data {
40    struct i2c_client *client;
41    struct pca9532_led leds[16];
42    struct mutex update_lock;
43    struct input_dev *idev;
44    struct work_struct work;
45#ifdef CONFIG_LEDS_PCA9532_GPIO
46    struct gpio_chip gpio;
47#endif
48    const struct pca9532_chip_info *chip_info;
49    u8 pwm[2];
50    u8 psc[2];
51};
52
53static int pca9532_probe(struct i2c_client *client,
54    const struct i2c_device_id *id);
55static int pca9532_remove(struct i2c_client *client);
56
57enum {
58    pca9530,
59    pca9531,
60    pca9532,
61    pca9533,
62};
63
64static const struct i2c_device_id pca9532_id[] = {
65    { "pca9530", pca9530 },
66    { "pca9531", pca9531 },
67    { "pca9532", pca9532 },
68    { "pca9533", pca9533 },
69    { }
70};
71
72MODULE_DEVICE_TABLE(i2c, pca9532_id);
73
74static const struct pca9532_chip_info pca9532_chip_info_tbl[] = {
75    [pca9530] = {
76        .num_leds = 2,
77    },
78    [pca9531] = {
79        .num_leds = 8,
80    },
81    [pca9532] = {
82        .num_leds = 16,
83    },
84    [pca9533] = {
85        .num_leds = 4,
86    },
87};
88
89static struct i2c_driver pca9532_driver = {
90    .driver = {
91        .name = "leds-pca953x",
92    },
93    .probe = pca9532_probe,
94    .remove = pca9532_remove,
95    .id_table = pca9532_id,
96};
97
98/* We have two pwm/blinkers, but 16 possible leds to drive. Additionally,
99 * the clever Thecus people are using one pwm to drive the beeper. So,
100 * as a compromise we average one pwm to the values requested by all
101 * leds that are not ON/OFF.
102 * */
103static int pca9532_calcpwm(struct i2c_client *client, int pwm, int blink,
104    enum led_brightness value)
105{
106    int a = 0, b = 0, i = 0;
107    struct pca9532_data *data = i2c_get_clientdata(client);
108    for (i = 0; i < data->chip_info->num_leds; i++) {
109        if (data->leds[i].type == PCA9532_TYPE_LED &&
110            data->leds[i].state == PCA9532_PWM0+pwm) {
111                a++;
112                b += data->leds[i].ldev.brightness;
113        }
114    }
115    if (a == 0) {
116        dev_err(&client->dev,
117        "fear of division by zero %d/%d, wanted %d\n",
118            b, a, value);
119        return -EINVAL;
120    }
121    b = b/a;
122    if (b > 0xFF)
123        return -EINVAL;
124    data->pwm[pwm] = b;
125    data->psc[pwm] = blink;
126    return 0;
127}
128
129static int pca9532_setpwm(struct i2c_client *client, int pwm)
130{
131    struct pca9532_data *data = i2c_get_clientdata(client);
132    u8 maxleds = data->chip_info->num_leds;
133
134    mutex_lock(&data->update_lock);
135    i2c_smbus_write_byte_data(client, PCA9532_REG_PWM(maxleds, pwm),
136        data->pwm[pwm]);
137    i2c_smbus_write_byte_data(client, PCA9532_REG_PSC(maxleds, pwm),
138        data->psc[pwm]);
139    mutex_unlock(&data->update_lock);
140    return 0;
141}
142
143/* Set LED routing */
144static void pca9532_setled(struct pca9532_led *led)
145{
146    struct i2c_client *client = led->client;
147    struct pca9532_data *data = i2c_get_clientdata(client);
148    u8 maxleds = data->chip_info->num_leds;
149    char reg;
150
151    mutex_lock(&data->update_lock);
152    reg = i2c_smbus_read_byte_data(client, LED_REG(maxleds, led->id));
153    /* zero led bits */
154    reg = reg & ~(0x3<<LED_NUM(led->id)*2);
155    /* set the new value */
156    reg = reg | (led->state << LED_NUM(led->id)*2);
157    i2c_smbus_write_byte_data(client, LED_REG(maxleds, led->id), reg);
158    mutex_unlock(&data->update_lock);
159}
160
161static void pca9532_set_brightness(struct led_classdev *led_cdev,
162    enum led_brightness value)
163{
164    int err = 0;
165    struct pca9532_led *led = ldev_to_led(led_cdev);
166
167    if (value == LED_OFF)
168        led->state = PCA9532_OFF;
169    else if (value == LED_FULL)
170        led->state = PCA9532_ON;
171    else {
172        led->state = PCA9532_PWM0; /* Thecus: hardcode one pwm */
173        err = pca9532_calcpwm(led->client, 0, 0, value);
174        if (err)
175            return; /* XXX: led api doesn't allow error code? */
176    }
177    schedule_work(&led->work);
178}
179
180static int pca9532_set_blink(struct led_classdev *led_cdev,
181    unsigned long *delay_on, unsigned long *delay_off)
182{
183    struct pca9532_led *led = ldev_to_led(led_cdev);
184    struct i2c_client *client = led->client;
185    int psc;
186    int err = 0;
187
188    if (*delay_on == 0 && *delay_off == 0) {
189        /* led subsystem ask us for a blink rate */
190        *delay_on = 1000;
191        *delay_off = 1000;
192    }
193    if (*delay_on != *delay_off || *delay_on > 1690 || *delay_on < 6)
194        return -EINVAL;
195
196    /* Thecus specific: only use PSC/PWM 0 */
197    psc = (*delay_on * 152-1)/1000;
198    err = pca9532_calcpwm(client, 0, psc, led_cdev->brightness);
199    if (err)
200        return err;
201    schedule_work(&led->work);
202    return 0;
203}
204
205static int pca9532_event(struct input_dev *dev, unsigned int type,
206    unsigned int code, int value)
207{
208    struct pca9532_data *data = input_get_drvdata(dev);
209
210    if (!(type == EV_SND && (code == SND_BELL || code == SND_TONE)))
211        return -1;
212
213    /* XXX: allow different kind of beeps with psc/pwm modifications */
214    if (value > 1 && value < 32767)
215        data->pwm[1] = 127;
216    else
217        data->pwm[1] = 0;
218
219    schedule_work(&data->work);
220
221    return 0;
222}
223
224static void pca9532_input_work(struct work_struct *work)
225{
226    struct pca9532_data *data =
227        container_of(work, struct pca9532_data, work);
228    u8 maxleds = data->chip_info->num_leds;
229
230    mutex_lock(&data->update_lock);
231    i2c_smbus_write_byte_data(data->client, PCA9532_REG_PWM(maxleds, 1),
232        data->pwm[1]);
233    mutex_unlock(&data->update_lock);
234}
235
236static void pca9532_led_work(struct work_struct *work)
237{
238    struct pca9532_led *led;
239    led = container_of(work, struct pca9532_led, work);
240    if (led->state == PCA9532_PWM0)
241        pca9532_setpwm(led->client, 0);
242    pca9532_setled(led);
243}
244
245#ifdef CONFIG_LEDS_PCA9532_GPIO
246static int pca9532_gpio_request_pin(struct gpio_chip *gc, unsigned offset)
247{
248    struct pca9532_data *data = container_of(gc, struct pca9532_data, gpio);
249    struct pca9532_led *led = &data->leds[offset];
250
251    if (led->type == PCA9532_TYPE_GPIO)
252        return 0;
253
254    return -EBUSY;
255}
256
257static void pca9532_gpio_set_value(struct gpio_chip *gc, unsigned offset, int val)
258{
259    struct pca9532_data *data = container_of(gc, struct pca9532_data, gpio);
260    struct pca9532_led *led = &data->leds[offset];
261
262    if (val)
263        led->state = PCA9532_ON;
264    else
265        led->state = PCA9532_OFF;
266
267    pca9532_setled(led);
268}
269
270static int pca9532_gpio_get_value(struct gpio_chip *gc, unsigned offset)
271{
272    struct pca9532_data *data = container_of(gc, struct pca9532_data, gpio);
273    unsigned char reg;
274
275    reg = i2c_smbus_read_byte_data(data->client, PCA9532_REG_INPUT(offset));
276
277    return !!(reg & (1 << (offset % 8)));
278}
279
280static int pca9532_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
281{
282    /* To use as input ensure pin is not driven */
283    pca9532_gpio_set_value(gc, offset, 0);
284
285    return 0;
286}
287
288static int pca9532_gpio_direction_output(struct gpio_chip *gc, unsigned offset, int val)
289{
290    pca9532_gpio_set_value(gc, offset, val);
291
292    return 0;
293}
294#endif /* CONFIG_LEDS_PCA9532_GPIO */
295
296static int pca9532_destroy_devices(struct pca9532_data *data, int n_devs)
297{
298    int i = n_devs;
299
300    if (!data)
301        return -EINVAL;
302
303    while (--i >= 0) {
304        switch (data->leds[i].type) {
305        case PCA9532_TYPE_NONE:
306        case PCA9532_TYPE_GPIO:
307            break;
308        case PCA9532_TYPE_LED:
309            led_classdev_unregister(&data->leds[i].ldev);
310            cancel_work_sync(&data->leds[i].work);
311            break;
312        case PCA9532_TYPE_N2100_BEEP:
313            if (data->idev != NULL) {
314                cancel_work_sync(&data->work);
315                data->idev = NULL;
316            }
317            break;
318        }
319    }
320
321#ifdef CONFIG_LEDS_PCA9532_GPIO
322    if (data->gpio.dev) {
323        int err = gpiochip_remove(&data->gpio);
324        if (err) {
325            dev_err(&data->client->dev, "%s failed, %d\n",
326                        "gpiochip_remove()", err);
327            return err;
328        }
329    }
330#endif
331
332    return 0;
333}
334
335static int pca9532_configure(struct i2c_client *client,
336    struct pca9532_data *data, struct pca9532_platform_data *pdata)
337{
338    int i, err = 0;
339    int gpios = 0;
340    u8 maxleds = data->chip_info->num_leds;
341
342    for (i = 0; i < 2; i++) {
343        data->pwm[i] = pdata->pwm[i];
344        data->psc[i] = pdata->psc[i];
345        i2c_smbus_write_byte_data(client, PCA9532_REG_PWM(maxleds, i),
346            data->pwm[i]);
347        i2c_smbus_write_byte_data(client, PCA9532_REG_PSC(maxleds, i),
348            data->psc[i]);
349    }
350
351    for (i = 0; i < data->chip_info->num_leds; i++) {
352        struct pca9532_led *led = &data->leds[i];
353        struct pca9532_led *pled = &pdata->leds[i];
354        led->client = client;
355        led->id = i;
356        led->type = pled->type;
357        switch (led->type) {
358        case PCA9532_TYPE_NONE:
359            break;
360        case PCA9532_TYPE_GPIO:
361            gpios++;
362            break;
363        case PCA9532_TYPE_LED:
364            led->state = pled->state;
365            led->name = pled->name;
366            led->ldev.name = led->name;
367            led->ldev.brightness = LED_OFF;
368            led->ldev.brightness_set = pca9532_set_brightness;
369            led->ldev.blink_set = pca9532_set_blink;
370            INIT_WORK(&led->work, pca9532_led_work);
371            err = led_classdev_register(&client->dev, &led->ldev);
372            if (err < 0) {
373                dev_err(&client->dev,
374                    "couldn't register LED %s\n",
375                    led->name);
376                goto exit;
377            }
378            pca9532_setled(led);
379            break;
380        case PCA9532_TYPE_N2100_BEEP:
381            BUG_ON(data->idev);
382            led->state = PCA9532_PWM1;
383            pca9532_setled(led);
384            data->idev = devm_input_allocate_device(&client->dev);
385            if (data->idev == NULL) {
386                err = -ENOMEM;
387                goto exit;
388            }
389            data->idev->name = pled->name;
390            data->idev->phys = "i2c/pca9532";
391            data->idev->id.bustype = BUS_HOST;
392            data->idev->id.vendor = 0x001f;
393            data->idev->id.product = 0x0001;
394            data->idev->id.version = 0x0100;
395            data->idev->evbit[0] = BIT_MASK(EV_SND);
396            data->idev->sndbit[0] = BIT_MASK(SND_BELL) |
397                        BIT_MASK(SND_TONE);
398            data->idev->event = pca9532_event;
399            input_set_drvdata(data->idev, data);
400            INIT_WORK(&data->work, pca9532_input_work);
401            err = input_register_device(data->idev);
402            if (err) {
403                cancel_work_sync(&data->work);
404                data->idev = NULL;
405                goto exit;
406            }
407            break;
408        }
409    }
410
411#ifdef CONFIG_LEDS_PCA9532_GPIO
412    if (gpios) {
413        data->gpio.label = "gpio-pca9532";
414        data->gpio.direction_input = pca9532_gpio_direction_input;
415        data->gpio.direction_output = pca9532_gpio_direction_output;
416        data->gpio.set = pca9532_gpio_set_value;
417        data->gpio.get = pca9532_gpio_get_value;
418        data->gpio.request = pca9532_gpio_request_pin;
419        data->gpio.can_sleep = 1;
420        data->gpio.base = pdata->gpio_base;
421        data->gpio.ngpio = data->chip_info->num_leds;
422        data->gpio.dev = &client->dev;
423        data->gpio.owner = THIS_MODULE;
424
425        err = gpiochip_add(&data->gpio);
426        if (err) {
427            /* Use data->gpio.dev as a flag for freeing gpiochip */
428            data->gpio.dev = NULL;
429            dev_warn(&client->dev, "could not add gpiochip\n");
430        } else {
431            dev_info(&client->dev, "gpios %i...%i\n",
432                data->gpio.base, data->gpio.base +
433                data->gpio.ngpio - 1);
434        }
435    }
436#endif
437
438    return 0;
439
440exit:
441    pca9532_destroy_devices(data, i);
442    return err;
443}
444
445static int pca9532_probe(struct i2c_client *client,
446    const struct i2c_device_id *id)
447{
448    struct pca9532_data *data = i2c_get_clientdata(client);
449    struct pca9532_platform_data *pca9532_pdata = client->dev.platform_data;
450
451    if (!pca9532_pdata)
452        return -EIO;
453
454    if (!i2c_check_functionality(client->adapter,
455        I2C_FUNC_SMBUS_BYTE_DATA))
456        return -EIO;
457
458    data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
459    if (!data)
460        return -ENOMEM;
461
462    data->chip_info = &pca9532_chip_info_tbl[id->driver_data];
463
464    dev_info(&client->dev, "setting platform data\n");
465    i2c_set_clientdata(client, data);
466    data->client = client;
467    mutex_init(&data->update_lock);
468
469    return pca9532_configure(client, data, pca9532_pdata);
470}
471
472static int pca9532_remove(struct i2c_client *client)
473{
474    struct pca9532_data *data = i2c_get_clientdata(client);
475    int err;
476
477    err = pca9532_destroy_devices(data, data->chip_info->num_leds);
478    if (err)
479        return err;
480
481    return 0;
482}
483
484module_i2c_driver(pca9532_driver);
485
486MODULE_AUTHOR("Riku Voipio");
487MODULE_LICENSE("GPL");
488MODULE_DESCRIPTION("PCA 9532 LED dimmer");
489

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