1/*
  2 * linux/drivers/mfd/aat2870-core.c
  3 *
  4 * Copyright (c) 2011, NVIDIA Corporation.
  5 * Author: Jin Park <jinyoungp@nvidia.com>
  6 *
  7 * This program is free software; you can redistribute it and/or
  8 * modify it under the terms of the GNU General Public License
  9 * version 2 as published by the Free Software Foundation.
 10 *
 11 * This program is distributed in the hope that it will be useful, but
 12 * WITHOUT ANY WARRANTY; without even the implied warranty of
 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 14 * General Public License for more details.
 15 *
 16 * You should have received a copy of the GNU General Public License
 17 * along with this program; if not, write to the Free Software
 18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 19 * 02110-1301 USA
 20 */
 21
 22#include <linux/kernel.h>
 23#include <linux/module.h>
 24#include <linux/init.h>
 25#include <linux/debugfs.h>
 26#include <linux/slab.h>
 27#include <linux/uaccess.h>
 28#include <linux/i2c.h>
 29#include <linux/delay.h>
 30#include <linux/gpio.h>
 31#include <linux/mfd/core.h>
 32#include <linux/mfd/aat2870.h>
 33#include <linux/regulator/machine.h>
 34
 35static struct aat2870_register aat2870_regs[AAT2870_REG_NUM] = {
 36	/* readable, writeable, value */
 37	{ 0, 1, 0x00 },	/* 0x00 AAT2870_BL_CH_EN */
 38	{ 0, 1, 0x16 },	/* 0x01 AAT2870_BLM */
 39	{ 0, 1, 0x16 },	/* 0x02 AAT2870_BLS */
 40	{ 0, 1, 0x56 },	/* 0x03 AAT2870_BL1 */
 41	{ 0, 1, 0x56 },	/* 0x04 AAT2870_BL2 */
 42	{ 0, 1, 0x56 },	/* 0x05 AAT2870_BL3 */
 43	{ 0, 1, 0x56 },	/* 0x06 AAT2870_BL4 */
 44	{ 0, 1, 0x56 },	/* 0x07 AAT2870_BL5 */
 45	{ 0, 1, 0x56 },	/* 0x08 AAT2870_BL6 */
 46	{ 0, 1, 0x56 },	/* 0x09 AAT2870_BL7 */
 47	{ 0, 1, 0x56 },	/* 0x0A AAT2870_BL8 */
 48	{ 0, 1, 0x00 },	/* 0x0B AAT2870_FLR */
 49	{ 0, 1, 0x03 },	/* 0x0C AAT2870_FM */
 50	{ 0, 1, 0x03 },	/* 0x0D AAT2870_FS */
 51	{ 0, 1, 0x10 },	/* 0x0E AAT2870_ALS_CFG0 */
 52	{ 0, 1, 0x06 },	/* 0x0F AAT2870_ALS_CFG1 */
 53	{ 0, 1, 0x00 },	/* 0x10 AAT2870_ALS_CFG2 */
 54	{ 1, 0, 0x00 },	/* 0x11 AAT2870_AMB */
 55	{ 0, 1, 0x00 },	/* 0x12 AAT2870_ALS0 */
 56	{ 0, 1, 0x00 },	/* 0x13 AAT2870_ALS1 */
 57	{ 0, 1, 0x00 },	/* 0x14 AAT2870_ALS2 */
 58	{ 0, 1, 0x00 },	/* 0x15 AAT2870_ALS3 */
 59	{ 0, 1, 0x00 },	/* 0x16 AAT2870_ALS4 */
 60	{ 0, 1, 0x00 },	/* 0x17 AAT2870_ALS5 */
 61	{ 0, 1, 0x00 },	/* 0x18 AAT2870_ALS6 */
 62	{ 0, 1, 0x00 },	/* 0x19 AAT2870_ALS7 */
 63	{ 0, 1, 0x00 },	/* 0x1A AAT2870_ALS8 */
 64	{ 0, 1, 0x00 },	/* 0x1B AAT2870_ALS9 */
 65	{ 0, 1, 0x00 },	/* 0x1C AAT2870_ALSA */
 66	{ 0, 1, 0x00 },	/* 0x1D AAT2870_ALSB */
 67	{ 0, 1, 0x00 },	/* 0x1E AAT2870_ALSC */
 68	{ 0, 1, 0x00 },	/* 0x1F AAT2870_ALSD */
 69	{ 0, 1, 0x00 },	/* 0x20 AAT2870_ALSE */
 70	{ 0, 1, 0x00 },	/* 0x21 AAT2870_ALSF */
 71	{ 0, 1, 0x00 },	/* 0x22 AAT2870_SUB_SET */
 72	{ 0, 1, 0x00 },	/* 0x23 AAT2870_SUB_CTRL */
 73	{ 0, 1, 0x00 },	/* 0x24 AAT2870_LDO_AB */
 74	{ 0, 1, 0x00 },	/* 0x25 AAT2870_LDO_CD */
 75	{ 0, 1, 0x00 },	/* 0x26 AAT2870_LDO_EN */
 76};
 77
 78static struct mfd_cell aat2870_devs[] = {
 79	{
 80		.name = "aat2870-backlight",
 81		.id = AAT2870_ID_BL,
 82		.pdata_size = sizeof(struct aat2870_bl_platform_data),
 83	},
 84	{
 85		.name = "aat2870-regulator",
 86		.id = AAT2870_ID_LDOA,
 87		.pdata_size = sizeof(struct regulator_init_data),
 88	},
 89	{
 90		.name = "aat2870-regulator",
 91		.id = AAT2870_ID_LDOB,
 92		.pdata_size = sizeof(struct regulator_init_data),
 93	},
 94	{
 95		.name = "aat2870-regulator",
 96		.id = AAT2870_ID_LDOC,
 97		.pdata_size = sizeof(struct regulator_init_data),
 98	},
 99	{
100		.name = "aat2870-regulator",
101		.id = AAT2870_ID_LDOD,
102		.pdata_size = sizeof(struct regulator_init_data),
103	},
104};
105
106static int __aat2870_read(struct aat2870_data *aat2870, u8 addr, u8 *val)
107{
108	int ret;
109
110	if (addr >= AAT2870_REG_NUM) {
111		dev_err(aat2870->dev, "Invalid address, 0x%02x\n", addr);
112		return -EINVAL;
113	}
114
115	if (!aat2870->reg_cache[addr].readable) {
116		*val = aat2870->reg_cache[addr].value;
117		goto out;
118	}
119
120	ret = i2c_master_send(aat2870->client, &addr, 1);
121	if (ret < 0)
122		return ret;
123	if (ret != 1)
124		return -EIO;
125
126	ret = i2c_master_recv(aat2870->client, val, 1);
127	if (ret < 0)
128		return ret;
129	if (ret != 1)
130		return -EIO;
131
132out:
133	dev_dbg(aat2870->dev, "read: addr=0x%02x, val=0x%02x\n", addr, *val);
134	return 0;
135}
136
137static int __aat2870_write(struct aat2870_data *aat2870, u8 addr, u8 val)
138{
139	u8 msg[2];
140	int ret;
141
142	if (addr >= AAT2870_REG_NUM) {
143		dev_err(aat2870->dev, "Invalid address, 0x%02x\n", addr);
144		return -EINVAL;
145	}
146
147	if (!aat2870->reg_cache[addr].writeable) {
148		dev_err(aat2870->dev, "Address 0x%02x is not writeable\n",
149			addr);
150		return -EINVAL;
151	}
152
153	msg[0] = addr;
154	msg[1] = val;
155	ret = i2c_master_send(aat2870->client, msg, 2);
156	if (ret < 0)
157		return ret;
158	if (ret != 2)
159		return -EIO;
160
161	aat2870->reg_cache[addr].value = val;
162
163	dev_dbg(aat2870->dev, "write: addr=0x%02x, val=0x%02x\n", addr, val);
164	return 0;
165}
166
167static int aat2870_read(struct aat2870_data *aat2870, u8 addr, u8 *val)
168{
169	int ret;
170
171	mutex_lock(&aat2870->io_lock);
172	ret = __aat2870_read(aat2870, addr, val);
173	mutex_unlock(&aat2870->io_lock);
174
175	return ret;
176}
177
178static int aat2870_write(struct aat2870_data *aat2870, u8 addr, u8 val)
179{
180	int ret;
181
182	mutex_lock(&aat2870->io_lock);
183	ret = __aat2870_write(aat2870, addr, val);
184	mutex_unlock(&aat2870->io_lock);
185
186	return ret;
187}
188
189static int aat2870_update(struct aat2870_data *aat2870, u8 addr, u8 mask,
190			  u8 val)
191{
192	int change;
193	u8 old_val, new_val;
194	int ret;
195
196	mutex_lock(&aat2870->io_lock);
197
198	ret = __aat2870_read(aat2870, addr, &old_val);
199	if (ret)
200		goto out_unlock;
201
202	new_val = (old_val & ~mask) | (val & mask);
203	change = old_val != new_val;
204	if (change)
205		ret = __aat2870_write(aat2870, addr, new_val);
206
207out_unlock:
208	mutex_unlock(&aat2870->io_lock);
209
210	return ret;
211}
212
213static inline void aat2870_enable(struct aat2870_data *aat2870)
214{
215	if (aat2870->en_pin >= 0)
216		gpio_set_value(aat2870->en_pin, 1);
217
218	aat2870->is_enable = 1;
219}
220
221static inline void aat2870_disable(struct aat2870_data *aat2870)
222{
223	if (aat2870->en_pin >= 0)
224		gpio_set_value(aat2870->en_pin, 0);
225
226	aat2870->is_enable = 0;
227}
228
229#ifdef CONFIG_DEBUG_FS
230static ssize_t aat2870_dump_reg(struct aat2870_data *aat2870, char *buf)
231{
232	u8 addr, val;
233	ssize_t count = 0;
234	int ret;
235
236	count += sprintf(buf, "aat2870 registers\n");
237	for (addr = 0; addr < AAT2870_REG_NUM; addr++) {
238		count += sprintf(buf + count, "0x%02x: ", addr);
239		if (count >= PAGE_SIZE - 1)
240			break;
241
242		ret = aat2870->read(aat2870, addr, &val);
243		if (ret == 0)
244			count += snprintf(buf + count, PAGE_SIZE - count,
245					  "0x%02x", val);
246		else
247			count += snprintf(buf + count, PAGE_SIZE - count,
248					  "<read fail: %d>", ret);
249
250		if (count >= PAGE_SIZE - 1)
251			break;
252
253		count += snprintf(buf + count, PAGE_SIZE - count, "\n");
254		if (count >= PAGE_SIZE - 1)
255			break;
256	}
257
258	/* Truncate count; min() would cause a warning */
259	if (count >= PAGE_SIZE)
260		count = PAGE_SIZE - 1;
261
262	return count;
263}
264
265static ssize_t aat2870_reg_read_file(struct file *file, char __user *user_buf,
266				     size_t count, loff_t *ppos)
267{
268	struct aat2870_data *aat2870 = file->private_data;
269	char *buf;
270	ssize_t ret;
271
272	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
273	if (!buf)
274		return -ENOMEM;
275
276	ret = aat2870_dump_reg(aat2870, buf);
277	if (ret >= 0)
278		ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);
279
280	kfree(buf);
281
282	return ret;
283}
284
285static ssize_t aat2870_reg_write_file(struct file *file,
286				      const char __user *user_buf, size_t count,
287				      loff_t *ppos)
288{
289	struct aat2870_data *aat2870 = file->private_data;
290	char buf[32];
291	ssize_t buf_size;
292	char *start = buf;
293	unsigned long addr, val;
294	int ret;
295
296	buf_size = min(count, (sizeof(buf)-1));
297	if (copy_from_user(buf, user_buf, buf_size)) {
298		dev_err(aat2870->dev, "Failed to copy from user\n");
299		return -EFAULT;
300	}
301	buf[buf_size] = 0;
302
303	while (*start == ' ')
304		start++;
305
306	addr = simple_strtoul(start, &start, 16);
307	if (addr >= AAT2870_REG_NUM) {
308		dev_err(aat2870->dev, "Invalid address, 0x%lx\n", addr);
309		return -EINVAL;
310	}
311
312	while (*start == ' ')
313		start++;
314
315	if (strict_strtoul(start, 16, &val))
316		return -EINVAL;
317
318	ret = aat2870->write(aat2870, (u8)addr, (u8)val);
319	if (ret)
320		return ret;
321
322	return buf_size;
323}
324
325static const struct file_operations aat2870_reg_fops = {
326	.open = simple_open,
327	.read = aat2870_reg_read_file,
328	.write = aat2870_reg_write_file,
329};
330
331static void aat2870_init_debugfs(struct aat2870_data *aat2870)
332{
333	aat2870->dentry_root = debugfs_create_dir("aat2870", NULL);
334	if (!aat2870->dentry_root) {
335		dev_warn(aat2870->dev,
336			 "Failed to create debugfs root directory\n");
337		return;
338	}
339
340	aat2870->dentry_reg = debugfs_create_file("regs", 0644,
341						  aat2870->dentry_root,
342						  aat2870, &aat2870_reg_fops);
343	if (!aat2870->dentry_reg)
344		dev_warn(aat2870->dev,
345			 "Failed to create debugfs register file\n");
346}
347
348static void aat2870_uninit_debugfs(struct aat2870_data *aat2870)
349{
350	debugfs_remove_recursive(aat2870->dentry_root);
351}
352#else
353static inline void aat2870_init_debugfs(struct aat2870_data *aat2870)
354{
355}
356
357static inline void aat2870_uninit_debugfs(struct aat2870_data *aat2870)
358{
359}
360#endif /* CONFIG_DEBUG_FS */
361
362static int aat2870_i2c_probe(struct i2c_client *client,
363			     const struct i2c_device_id *id)
364{
365	struct aat2870_platform_data *pdata = client->dev.platform_data;
366	struct aat2870_data *aat2870;
367	int i, j;
368	int ret = 0;
369
370	aat2870 = kzalloc(sizeof(struct aat2870_data), GFP_KERNEL);
371	if (!aat2870) {
372		dev_err(&client->dev,
373			"Failed to allocate memory for aat2870\n");
374		ret = -ENOMEM;
375		goto out;
376	}
377
378	aat2870->dev = &client->dev;
379	dev_set_drvdata(aat2870->dev, aat2870);
380
381	aat2870->client = client;
382	i2c_set_clientdata(client, aat2870);
383
384	aat2870->reg_cache = aat2870_regs;
385
386	if (pdata->en_pin < 0)
387		aat2870->en_pin = -1;
388	else
389		aat2870->en_pin = pdata->en_pin;
390
391	aat2870->init = pdata->init;
392	aat2870->uninit = pdata->uninit;
393	aat2870->read = aat2870_read;
394	aat2870->write = aat2870_write;
395	aat2870->update = aat2870_update;
396
397	mutex_init(&aat2870->io_lock);
398
399	if (aat2870->init)
400		aat2870->init(aat2870);
401
402	if (aat2870->en_pin >= 0) {
403		ret = gpio_request_one(aat2870->en_pin, GPIOF_OUT_INIT_HIGH,
404				       "aat2870-en");
405		if (ret < 0) {
406			dev_err(&client->dev,
407				"Failed to request GPIO %d\n", aat2870->en_pin);
408			goto out_kfree;
409		}
410	}
411
412	aat2870_enable(aat2870);
413
414	for (i = 0; i < pdata->num_subdevs; i++) {
415		for (j = 0; j < ARRAY_SIZE(aat2870_devs); j++) {
416			if ((pdata->subdevs[i].id == aat2870_devs[j].id) &&
417					!strcmp(pdata->subdevs[i].name,
418						aat2870_devs[j].name)) {
419				aat2870_devs[j].platform_data =
420					pdata->subdevs[i].platform_data;
421				break;
422			}
423		}
424	}
425
426	ret = mfd_add_devices(aat2870->dev, 0, aat2870_devs,
427			      ARRAY_SIZE(aat2870_devs), NULL, 0);
428	if (ret != 0) {
429		dev_err(aat2870->dev, "Failed to add subdev: %d\n", ret);
430		goto out_disable;
431	}
432
433	aat2870_init_debugfs(aat2870);
434
435	return 0;
436
437out_disable:
438	aat2870_disable(aat2870);
439	if (aat2870->en_pin >= 0)
440		gpio_free(aat2870->en_pin);
441out_kfree:
442	kfree(aat2870);
443out:
444	return ret;
445}
446
447static int aat2870_i2c_remove(struct i2c_client *client)
448{
449	struct aat2870_data *aat2870 = i2c_get_clientdata(client);
450
451	aat2870_uninit_debugfs(aat2870);
452
453	mfd_remove_devices(aat2870->dev);
454	aat2870_disable(aat2870);
455	if (aat2870->en_pin >= 0)
456		gpio_free(aat2870->en_pin);
457	if (aat2870->uninit)
458		aat2870->uninit(aat2870);
459	kfree(aat2870);
460
461	return 0;
462}
463
464#ifdef CONFIG_PM_SLEEP
465static int aat2870_i2c_suspend(struct device *dev)
466{
467	struct i2c_client *client = to_i2c_client(dev);
468	struct aat2870_data *aat2870 = i2c_get_clientdata(client);
469
470	aat2870_disable(aat2870);
471
472	return 0;
473}
474
475static int aat2870_i2c_resume(struct device *dev)
476{
477	struct i2c_client *client = to_i2c_client(dev);
478	struct aat2870_data *aat2870 = i2c_get_clientdata(client);
479	struct aat2870_register *reg = NULL;
480	int i;
481
482	aat2870_enable(aat2870);
483
484	/* restore registers */
485	for (i = 0; i < AAT2870_REG_NUM; i++) {
486		reg = &aat2870->reg_cache[i];
487		if (reg->writeable)
488			aat2870->write(aat2870, i, reg->value);
489	}
490
491	return 0;
492}
493#endif /* CONFIG_PM_SLEEP */
494
495static SIMPLE_DEV_PM_OPS(aat2870_pm_ops, aat2870_i2c_suspend,
496			 aat2870_i2c_resume);
497
498static const struct i2c_device_id aat2870_i2c_id_table[] = {
499	{ "aat2870", 0 },
500	{ }
501};
502MODULE_DEVICE_TABLE(i2c, aat2870_i2c_id_table);
503
504static struct i2c_driver aat2870_i2c_driver = {
505	.driver = {
506		.name	= "aat2870",
507		.owner	= THIS_MODULE,
508		.pm	= &aat2870_pm_ops,
509	},
510	.probe		= aat2870_i2c_probe,
511	.remove		= aat2870_i2c_remove,
512	.id_table	= aat2870_i2c_id_table,
513};
514
515static int __init aat2870_init(void)
516{
517	return i2c_add_driver(&aat2870_i2c_driver);
518}
519subsys_initcall(aat2870_init);
520
521static void __exit aat2870_exit(void)
522{
523	i2c_del_driver(&aat2870_i2c_driver);
524}
525module_exit(aat2870_exit);
526
527MODULE_DESCRIPTION("Core support for the AnalogicTech AAT2870");
528MODULE_LICENSE("GPL");
529MODULE_AUTHOR("Jin Park <jinyoungp@nvidia.com>");