Root/drivers/leds/leds-lp5523.c

1/*
2 * lp5523.c - LP5523 LED Driver
3 *
4 * Copyright (C) 2010 Nokia Corporation
5 * Copyright (C) 2012 Texas Instruments
6 *
7 * Contact: Samu Onkalo <samu.p.onkalo@nokia.com>
8 * Milo(Woogyom) Kim <milo.kim@ti.com>
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * version 2 as published by the Free Software Foundation.
13 *
14 * This program is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
22 * 02110-1301 USA
23 */
24
25#include <linux/delay.h>
26#include <linux/firmware.h>
27#include <linux/i2c.h>
28#include <linux/init.h>
29#include <linux/leds.h>
30#include <linux/module.h>
31#include <linux/mutex.h>
32#include <linux/platform_data/leds-lp55xx.h>
33#include <linux/slab.h>
34
35#include "leds-lp55xx-common.h"
36
37#define LP5523_PROGRAM_LENGTH 32
38#define LP5523_MAX_LEDS 9
39
40/* Registers */
41#define LP5523_REG_ENABLE 0x00
42#define LP5523_REG_OP_MODE 0x01
43#define LP5523_REG_ENABLE_LEDS_MSB 0x04
44#define LP5523_REG_ENABLE_LEDS_LSB 0x05
45#define LP5523_REG_LED_PWM_BASE 0x16
46#define LP5523_REG_LED_CURRENT_BASE 0x26
47#define LP5523_REG_CONFIG 0x36
48#define LP5523_REG_STATUS 0x3A
49#define LP5523_REG_RESET 0x3D
50#define LP5523_REG_LED_TEST_CTRL 0x41
51#define LP5523_REG_LED_TEST_ADC 0x42
52#define LP5523_REG_PROG_PAGE_SEL 0x4F
53#define LP5523_REG_PROG_MEM 0x50
54
55/* Bit description in registers */
56#define LP5523_ENABLE 0x40
57#define LP5523_AUTO_INC 0x40
58#define LP5523_PWR_SAVE 0x20
59#define LP5523_PWM_PWR_SAVE 0x04
60#define LP5523_CP_AUTO 0x18
61#define LP5523_AUTO_CLK 0x02
62
63#define LP5523_EN_LEDTEST 0x80
64#define LP5523_LEDTEST_DONE 0x80
65#define LP5523_RESET 0xFF
66#define LP5523_ADC_SHORTCIRC_LIM 80
67#define LP5523_EXT_CLK_USED 0x08
68
69/* Memory Page Selection */
70#define LP5523_PAGE_ENG1 0
71#define LP5523_PAGE_ENG2 1
72#define LP5523_PAGE_ENG3 2
73
74/* Program Memory Operations */
75#define LP5523_MODE_ENG1_M 0x30 /* Operation Mode Register */
76#define LP5523_MODE_ENG2_M 0x0C
77#define LP5523_MODE_ENG3_M 0x03
78#define LP5523_LOAD_ENG1 0x10
79#define LP5523_LOAD_ENG2 0x04
80#define LP5523_LOAD_ENG3 0x01
81
82#define LP5523_ENG1_IS_LOADING(mode) \
83    ((mode & LP5523_MODE_ENG1_M) == LP5523_LOAD_ENG1)
84#define LP5523_ENG2_IS_LOADING(mode) \
85    ((mode & LP5523_MODE_ENG2_M) == LP5523_LOAD_ENG2)
86#define LP5523_ENG3_IS_LOADING(mode) \
87    ((mode & LP5523_MODE_ENG3_M) == LP5523_LOAD_ENG3)
88
89#define LP5523_EXEC_ENG1_M 0x30 /* Enable Register */
90#define LP5523_EXEC_ENG2_M 0x0C
91#define LP5523_EXEC_ENG3_M 0x03
92#define LP5523_EXEC_M 0x3F
93#define LP5523_RUN_ENG1 0x20
94#define LP5523_RUN_ENG2 0x08
95#define LP5523_RUN_ENG3 0x02
96
97enum lp5523_chip_id {
98    LP5523,
99    LP55231,
100};
101
102static inline void lp5523_wait_opmode_done(void)
103{
104    usleep_range(1000, 2000);
105}
106
107static void lp5523_set_led_current(struct lp55xx_led *led, u8 led_current)
108{
109    led->led_current = led_current;
110    lp55xx_write(led->chip, LP5523_REG_LED_CURRENT_BASE + led->chan_nr,
111        led_current);
112}
113
114static int lp5523_post_init_device(struct lp55xx_chip *chip)
115{
116    int ret;
117
118    ret = lp55xx_write(chip, LP5523_REG_ENABLE, LP5523_ENABLE);
119    if (ret)
120        return ret;
121
122    /* Chip startup time is 500 us, 1 - 2 ms gives some margin */
123    usleep_range(1000, 2000);
124
125    ret = lp55xx_write(chip, LP5523_REG_CONFIG,
126                LP5523_AUTO_INC | LP5523_PWR_SAVE |
127                LP5523_CP_AUTO | LP5523_AUTO_CLK |
128                LP5523_PWM_PWR_SAVE);
129    if (ret)
130        return ret;
131
132    /* turn on all leds */
133    ret = lp55xx_write(chip, LP5523_REG_ENABLE_LEDS_MSB, 0x01);
134    if (ret)
135        return ret;
136
137    return lp55xx_write(chip, LP5523_REG_ENABLE_LEDS_LSB, 0xff);
138}
139
140static void lp5523_load_engine(struct lp55xx_chip *chip)
141{
142    enum lp55xx_engine_index idx = chip->engine_idx;
143    u8 mask[] = {
144        [LP55XX_ENGINE_1] = LP5523_MODE_ENG1_M,
145        [LP55XX_ENGINE_2] = LP5523_MODE_ENG2_M,
146        [LP55XX_ENGINE_3] = LP5523_MODE_ENG3_M,
147    };
148
149    u8 val[] = {
150        [LP55XX_ENGINE_1] = LP5523_LOAD_ENG1,
151        [LP55XX_ENGINE_2] = LP5523_LOAD_ENG2,
152        [LP55XX_ENGINE_3] = LP5523_LOAD_ENG3,
153    };
154
155    u8 page_sel[] = {
156        [LP55XX_ENGINE_1] = LP5523_PAGE_ENG1,
157        [LP55XX_ENGINE_2] = LP5523_PAGE_ENG2,
158        [LP55XX_ENGINE_3] = LP5523_PAGE_ENG3,
159    };
160
161    lp55xx_update_bits(chip, LP5523_REG_OP_MODE, mask[idx], val[idx]);
162
163    lp5523_wait_opmode_done();
164
165    lp55xx_write(chip, LP5523_REG_PROG_PAGE_SEL, page_sel[idx]);
166}
167
168static void lp5523_stop_engine(struct lp55xx_chip *chip)
169{
170    lp55xx_write(chip, LP5523_REG_OP_MODE, 0);
171    lp5523_wait_opmode_done();
172}
173
174static void lp5523_turn_off_channels(struct lp55xx_chip *chip)
175{
176    int i;
177
178    for (i = 0; i < LP5523_MAX_LEDS; i++)
179        lp55xx_write(chip, LP5523_REG_LED_PWM_BASE + i, 0);
180}
181
182static void lp5523_run_engine(struct lp55xx_chip *chip, bool start)
183{
184    int ret;
185    u8 mode;
186    u8 exec;
187
188    /* stop engine */
189    if (!start) {
190        lp5523_stop_engine(chip);
191        lp5523_turn_off_channels(chip);
192        return;
193    }
194
195    /*
196     * To run the engine,
197     * operation mode and enable register should updated at the same time
198     */
199
200    ret = lp55xx_read(chip, LP5523_REG_OP_MODE, &mode);
201    if (ret)
202        return;
203
204    ret = lp55xx_read(chip, LP5523_REG_ENABLE, &exec);
205    if (ret)
206        return;
207
208    /* change operation mode to RUN only when each engine is loading */
209    if (LP5523_ENG1_IS_LOADING(mode)) {
210        mode = (mode & ~LP5523_MODE_ENG1_M) | LP5523_RUN_ENG1;
211        exec = (exec & ~LP5523_EXEC_ENG1_M) | LP5523_RUN_ENG1;
212    }
213
214    if (LP5523_ENG2_IS_LOADING(mode)) {
215        mode = (mode & ~LP5523_MODE_ENG2_M) | LP5523_RUN_ENG2;
216        exec = (exec & ~LP5523_EXEC_ENG2_M) | LP5523_RUN_ENG2;
217    }
218
219    if (LP5523_ENG3_IS_LOADING(mode)) {
220        mode = (mode & ~LP5523_MODE_ENG3_M) | LP5523_RUN_ENG3;
221        exec = (exec & ~LP5523_EXEC_ENG3_M) | LP5523_RUN_ENG3;
222    }
223
224    lp55xx_write(chip, LP5523_REG_OP_MODE, mode);
225    lp5523_wait_opmode_done();
226
227    lp55xx_update_bits(chip, LP5523_REG_ENABLE, LP5523_EXEC_M, exec);
228}
229
230static int lp5523_update_program_memory(struct lp55xx_chip *chip,
231                    const u8 *data, size_t size)
232{
233    u8 pattern[LP5523_PROGRAM_LENGTH] = {0};
234    unsigned cmd;
235    char c[3];
236    int update_size;
237    int nrchars;
238    int offset = 0;
239    int ret;
240    int i;
241
242    /* clear program memory before updating */
243    for (i = 0; i < LP5523_PROGRAM_LENGTH; i++)
244        lp55xx_write(chip, LP5523_REG_PROG_MEM + i, 0);
245
246    i = 0;
247    while ((offset < size - 1) && (i < LP5523_PROGRAM_LENGTH)) {
248        /* separate sscanfs because length is working only for %s */
249        ret = sscanf(data + offset, "%2s%n ", c, &nrchars);
250        if (ret != 1)
251            goto err;
252
253        ret = sscanf(c, "%2x", &cmd);
254        if (ret != 1)
255            goto err;
256
257        pattern[i] = (u8)cmd;
258        offset += nrchars;
259        i++;
260    }
261
262    /* Each instruction is 16bit long. Check that length is even */
263    if (i % 2)
264        goto err;
265
266    update_size = i;
267    for (i = 0; i < update_size; i++)
268        lp55xx_write(chip, LP5523_REG_PROG_MEM + i, pattern[i]);
269
270    return 0;
271
272err:
273    dev_err(&chip->cl->dev, "wrong pattern format\n");
274    return -EINVAL;
275}
276
277static void lp5523_firmware_loaded(struct lp55xx_chip *chip)
278{
279    const struct firmware *fw = chip->fw;
280
281    if (fw->size > LP5523_PROGRAM_LENGTH) {
282        dev_err(&chip->cl->dev, "firmware data size overflow: %zu\n",
283            fw->size);
284        return;
285    }
286
287    /*
288     * Program momery sequence
289     * 1) set engine mode to "LOAD"
290     * 2) write firmware data into program memory
291     */
292
293    lp5523_load_engine(chip);
294    lp5523_update_program_memory(chip, fw->data, fw->size);
295}
296
297static ssize_t lp5523_selftest(struct device *dev,
298                   struct device_attribute *attr,
299                   char *buf)
300{
301    struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
302    struct lp55xx_chip *chip = led->chip;
303    struct lp55xx_platform_data *pdata = chip->pdata;
304    int i, ret, pos = 0;
305    u8 status, adc, vdd;
306
307    mutex_lock(&chip->lock);
308
309    ret = lp55xx_read(chip, LP5523_REG_STATUS, &status);
310    if (ret < 0)
311        goto fail;
312
313    /* Check that ext clock is really in use if requested */
314    if (pdata->clock_mode == LP55XX_CLOCK_EXT) {
315        if ((status & LP5523_EXT_CLK_USED) == 0)
316            goto fail;
317    }
318
319    /* Measure VDD (i.e. VBAT) first (channel 16 corresponds to VDD) */
320    lp55xx_write(chip, LP5523_REG_LED_TEST_CTRL, LP5523_EN_LEDTEST | 16);
321    usleep_range(3000, 6000); /* ADC conversion time is typically 2.7 ms */
322    ret = lp55xx_read(chip, LP5523_REG_STATUS, &status);
323    if (ret < 0)
324        goto fail;
325
326    if (!(status & LP5523_LEDTEST_DONE))
327        usleep_range(3000, 6000); /* Was not ready. Wait little bit */
328
329    ret = lp55xx_read(chip, LP5523_REG_LED_TEST_ADC, &vdd);
330    if (ret < 0)
331        goto fail;
332
333    vdd--; /* There may be some fluctuation in measurement */
334
335    for (i = 0; i < LP5523_MAX_LEDS; i++) {
336        /* Skip non-existing channels */
337        if (pdata->led_config[i].led_current == 0)
338            continue;
339
340        /* Set default current */
341        lp55xx_write(chip, LP5523_REG_LED_CURRENT_BASE + i,
342            pdata->led_config[i].led_current);
343
344        lp55xx_write(chip, LP5523_REG_LED_PWM_BASE + i, 0xff);
345        /* let current stabilize 2 - 4ms before measurements start */
346        usleep_range(2000, 4000);
347        lp55xx_write(chip, LP5523_REG_LED_TEST_CTRL,
348                 LP5523_EN_LEDTEST | i);
349        /* ADC conversion time is 2.7 ms typically */
350        usleep_range(3000, 6000);
351        ret = lp55xx_read(chip, LP5523_REG_STATUS, &status);
352        if (ret < 0)
353            goto fail;
354
355        if (!(status & LP5523_LEDTEST_DONE))
356            usleep_range(3000, 6000);/* Was not ready. Wait. */
357
358        ret = lp55xx_read(chip, LP5523_REG_LED_TEST_ADC, &adc);
359        if (ret < 0)
360            goto fail;
361
362        if (adc >= vdd || adc < LP5523_ADC_SHORTCIRC_LIM)
363            pos += sprintf(buf + pos, "LED %d FAIL\n", i);
364
365        lp55xx_write(chip, LP5523_REG_LED_PWM_BASE + i, 0x00);
366
367        /* Restore current */
368        lp55xx_write(chip, LP5523_REG_LED_CURRENT_BASE + i,
369            led->led_current);
370        led++;
371    }
372    if (pos == 0)
373        pos = sprintf(buf, "OK\n");
374    goto release_lock;
375fail:
376    pos = sprintf(buf, "FAIL\n");
377
378release_lock:
379    mutex_unlock(&chip->lock);
380
381    return pos;
382}
383
384static void lp5523_led_brightness_work(struct work_struct *work)
385{
386    struct lp55xx_led *led = container_of(work, struct lp55xx_led,
387                          brightness_work);
388    struct lp55xx_chip *chip = led->chip;
389
390    mutex_lock(&chip->lock);
391    lp55xx_write(chip, LP5523_REG_LED_PWM_BASE + led->chan_nr,
392             led->brightness);
393    mutex_unlock(&chip->lock);
394}
395
396static DEVICE_ATTR(selftest, S_IRUGO, lp5523_selftest, NULL);
397
398static struct attribute *lp5523_attributes[] = {
399    &dev_attr_selftest.attr,
400    NULL,
401};
402
403static const struct attribute_group lp5523_group = {
404    .attrs = lp5523_attributes,
405};
406
407/* Chip specific configurations */
408static struct lp55xx_device_config lp5523_cfg = {
409    .reset = {
410        .addr = LP5523_REG_RESET,
411        .val = LP5523_RESET,
412    },
413    .enable = {
414        .addr = LP5523_REG_ENABLE,
415        .val = LP5523_ENABLE,
416    },
417    .max_channel = LP5523_MAX_LEDS,
418    .post_init_device = lp5523_post_init_device,
419    .brightness_work_fn = lp5523_led_brightness_work,
420    .set_led_current = lp5523_set_led_current,
421    .firmware_cb = lp5523_firmware_loaded,
422    .run_engine = lp5523_run_engine,
423    .dev_attr_group = &lp5523_group,
424};
425
426static int lp5523_probe(struct i2c_client *client,
427            const struct i2c_device_id *id)
428{
429    int ret;
430    struct lp55xx_chip *chip;
431    struct lp55xx_led *led;
432    struct lp55xx_platform_data *pdata = client->dev.platform_data;
433
434    if (!pdata) {
435        dev_err(&client->dev, "no platform data\n");
436        return -EINVAL;
437    }
438
439    chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
440    if (!chip)
441        return -ENOMEM;
442
443    led = devm_kzalloc(&client->dev,
444            sizeof(*led) * pdata->num_channels, GFP_KERNEL);
445    if (!led)
446        return -ENOMEM;
447
448    chip->cl = client;
449    chip->pdata = pdata;
450    chip->cfg = &lp5523_cfg;
451
452    mutex_init(&chip->lock);
453
454    i2c_set_clientdata(client, led);
455
456    ret = lp55xx_init_device(chip);
457    if (ret)
458        goto err_init;
459
460    dev_info(&client->dev, "%s Programmable led chip found\n", id->name);
461
462    ret = lp55xx_register_leds(led, chip);
463    if (ret)
464        goto err_register_leds;
465
466    ret = lp55xx_register_sysfs(chip);
467    if (ret) {
468        dev_err(&client->dev, "registering sysfs failed\n");
469        goto err_register_sysfs;
470    }
471
472    return 0;
473
474err_register_sysfs:
475    lp55xx_unregister_leds(led, chip);
476err_register_leds:
477    lp55xx_deinit_device(chip);
478err_init:
479    return ret;
480}
481
482static int lp5523_remove(struct i2c_client *client)
483{
484    struct lp55xx_led *led = i2c_get_clientdata(client);
485    struct lp55xx_chip *chip = led->chip;
486
487    lp5523_stop_engine(chip);
488    lp55xx_unregister_sysfs(chip);
489    lp55xx_unregister_leds(led, chip);
490    lp55xx_deinit_device(chip);
491
492    return 0;
493}
494
495static const struct i2c_device_id lp5523_id[] = {
496    { "lp5523", LP5523 },
497    { "lp55231", LP55231 },
498    { }
499};
500
501MODULE_DEVICE_TABLE(i2c, lp5523_id);
502
503static struct i2c_driver lp5523_driver = {
504    .driver = {
505        .name = "lp5523x",
506    },
507    .probe = lp5523_probe,
508    .remove = lp5523_remove,
509    .id_table = lp5523_id,
510};
511
512module_i2c_driver(lp5523_driver);
513
514MODULE_AUTHOR("Mathias Nyman <mathias.nyman@nokia.com>");
515MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
516MODULE_DESCRIPTION("LP5523 LED engine");
517MODULE_LICENSE("GPL");
518

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