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v4.6
 
  1/*
  2 * Copyright (C) 2013 Capella Microsystems Inc.
  3 * Author: Kevin Tsai <ktsai@capellamicro.com>
  4 *
  5 * This program is free software; you can redistribute it and/or modify it
  6 * under the terms of the GNU General Public License version 2, as published
  7 * by the Free Software Foundation.
  8 */
  9
 
 10#include <linux/delay.h>
 11#include <linux/err.h>
 12#include <linux/i2c.h>
 13#include <linux/mutex.h>
 14#include <linux/module.h>
 
 15#include <linux/interrupt.h>
 16#include <linux/regulator/consumer.h>
 17#include <linux/iio/iio.h>
 18#include <linux/iio/sysfs.h>
 19#include <linux/iio/events.h>
 20#include <linux/init.h>
 21
 22/* Registers Address */
 23#define CM32181_REG_ADDR_CMD		0x00
 
 
 
 24#define CM32181_REG_ADDR_ALS		0x04
 25#define CM32181_REG_ADDR_STATUS		0x06
 26#define CM32181_REG_ADDR_ID		0x07
 27
 28/* Number of Configurable Registers */
 29#define CM32181_CONF_REG_NUM		0x01
 30
 31/* CMD register */
 32#define CM32181_CMD_ALS_ENABLE		0x00
 33#define CM32181_CMD_ALS_DISABLE		0x01
 34#define CM32181_CMD_ALS_INT_EN		0x02
 
 
 
 
 35
 36#define CM32181_CMD_ALS_IT_SHIFT	6
 37#define CM32181_CMD_ALS_IT_MASK		(0x0F << CM32181_CMD_ALS_IT_SHIFT)
 38#define CM32181_CMD_ALS_IT_DEFAULT	(0x00 << CM32181_CMD_ALS_IT_SHIFT)
 39
 40#define CM32181_CMD_ALS_SM_SHIFT	11
 41#define CM32181_CMD_ALS_SM_MASK		(0x03 << CM32181_CMD_ALS_SM_SHIFT)
 42#define CM32181_CMD_ALS_SM_DEFAULT	(0x01 << CM32181_CMD_ALS_SM_SHIFT)
 43
 44#define CM32181_MLUX_PER_BIT		5	/* ALS_SM=01 IT=800ms */
 45#define CM32181_MLUX_PER_BIT_BASE_IT	800000	/* Based on IT=800ms */
 46#define	CM32181_CALIBSCALE_DEFAULT	1000
 47#define CM32181_CALIBSCALE_RESOLUTION	1000
 48#define MLUX_PER_LUX			1000
 49
 50static const u8 cm32181_reg[CM32181_CONF_REG_NUM] = {
 51	CM32181_REG_ADDR_CMD,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 52};
 53
 54static const int als_it_bits[] = {12, 8, 0, 1, 2, 3};
 55static const int als_it_value[] = {25000, 50000, 100000, 200000, 400000,
 56	800000};
 57
 58struct cm32181_chip {
 59	struct i2c_client *client;
 
 60	struct mutex lock;
 61	u16 conf_regs[CM32181_CONF_REG_NUM];
 
 62	int calibscale;
 
 
 
 
 
 63};
 64
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 65/**
 66 * cm32181_reg_init() - Initialize CM32181 registers
 67 * @cm32181:	pointer of struct cm32181.
 68 *
 69 * Initialize CM32181 ambient light sensor register to default values.
 70 *
 71 * Return: 0 for success; otherwise for error code.
 72 */
 73static int cm32181_reg_init(struct cm32181_chip *cm32181)
 74{
 75	struct i2c_client *client = cm32181->client;
 76	int i;
 77	s32 ret;
 78
 79	ret = i2c_smbus_read_word_data(client, CM32181_REG_ADDR_ID);
 80	if (ret < 0)
 81		return ret;
 82
 83	/* check device ID */
 84	if ((ret & 0xFF) != 0x81)
 
 
 
 
 
 
 
 
 
 
 
 
 85		return -ENODEV;
 
 86
 87	/* Default Values */
 88	cm32181->conf_regs[CM32181_REG_ADDR_CMD] = CM32181_CMD_ALS_ENABLE |
 89			CM32181_CMD_ALS_IT_DEFAULT | CM32181_CMD_ALS_SM_DEFAULT;
 
 90	cm32181->calibscale = CM32181_CALIBSCALE_DEFAULT;
 
 
 
 
 
 91
 92	/* Initialize registers*/
 93	for (i = 0; i < CM32181_CONF_REG_NUM; i++) {
 94		ret = i2c_smbus_write_word_data(client, cm32181_reg[i],
 95			cm32181->conf_regs[i]);
 96		if (ret < 0)
 97			return ret;
 98	}
 99
100	return 0;
101}
102
103/**
104 *  cm32181_read_als_it() - Get sensor integration time (ms)
105 *  @cm32181:	pointer of struct cm32181
106 *  @val2:	pointer of int to load the als_it value.
107 *
108 *  Report the current integartion time by millisecond.
109 *
110 *  Return: IIO_VAL_INT_PLUS_MICRO for success, otherwise -EINVAL.
111 */
112static int cm32181_read_als_it(struct cm32181_chip *cm32181, int *val2)
113{
114	u16 als_it;
115	int i;
116
117	als_it = cm32181->conf_regs[CM32181_REG_ADDR_CMD];
118	als_it &= CM32181_CMD_ALS_IT_MASK;
119	als_it >>= CM32181_CMD_ALS_IT_SHIFT;
120	for (i = 0; i < ARRAY_SIZE(als_it_bits); i++) {
121		if (als_it == als_it_bits[i]) {
122			*val2 = als_it_value[i];
123			return IIO_VAL_INT_PLUS_MICRO;
124		}
125	}
126
127	return -EINVAL;
128}
129
130/**
131 * cm32181_write_als_it() - Write sensor integration time
132 * @cm32181:	pointer of struct cm32181.
133 * @val:	integration time by millisecond.
134 *
135 * Convert integration time (ms) to sensor value.
136 *
137 * Return: i2c_smbus_write_word_data command return value.
138 */
139static int cm32181_write_als_it(struct cm32181_chip *cm32181, int val)
140{
141	struct i2c_client *client = cm32181->client;
142	u16 als_it;
143	int ret, i, n;
144
145	n = ARRAY_SIZE(als_it_value);
146	for (i = 0; i < n; i++)
147		if (val <= als_it_value[i])
148			break;
149	if (i >= n)
150		i = n - 1;
151
152	als_it = als_it_bits[i];
153	als_it <<= CM32181_CMD_ALS_IT_SHIFT;
154
155	mutex_lock(&cm32181->lock);
156	cm32181->conf_regs[CM32181_REG_ADDR_CMD] &=
157		~CM32181_CMD_ALS_IT_MASK;
158	cm32181->conf_regs[CM32181_REG_ADDR_CMD] |=
159		als_it;
160	ret = i2c_smbus_write_word_data(client, CM32181_REG_ADDR_CMD,
161			cm32181->conf_regs[CM32181_REG_ADDR_CMD]);
162	mutex_unlock(&cm32181->lock);
163
164	return ret;
165}
166
167/**
168 * cm32181_get_lux() - report current lux value
169 * @cm32181:	pointer of struct cm32181.
170 *
171 * Convert sensor raw data to lux.  It depends on integration
172 * time and calibscale variable.
173 *
174 * Return: Positive value is lux, otherwise is error code.
175 */
176static int cm32181_get_lux(struct cm32181_chip *cm32181)
177{
178	struct i2c_client *client = cm32181->client;
179	int ret;
180	int als_it;
181	unsigned long lux;
182
183	ret = cm32181_read_als_it(cm32181, &als_it);
184	if (ret < 0)
185		return -EINVAL;
186
187	lux = CM32181_MLUX_PER_BIT;
188	lux *= CM32181_MLUX_PER_BIT_BASE_IT;
189	lux /= als_it;
190
191	ret = i2c_smbus_read_word_data(client, CM32181_REG_ADDR_ALS);
192	if (ret < 0)
193		return ret;
194
195	lux *= ret;
196	lux *= cm32181->calibscale;
197	lux /= CM32181_CALIBSCALE_RESOLUTION;
198	lux /= MLUX_PER_LUX;
199
200	if (lux > 0xFFFF)
201		lux = 0xFFFF;
202
203	return lux;
204}
205
206static int cm32181_read_raw(struct iio_dev *indio_dev,
207			    struct iio_chan_spec const *chan,
208			    int *val, int *val2, long mask)
209{
210	struct cm32181_chip *cm32181 = iio_priv(indio_dev);
211	int ret;
212
213	switch (mask) {
214	case IIO_CHAN_INFO_PROCESSED:
215		ret = cm32181_get_lux(cm32181);
216		if (ret < 0)
217			return ret;
218		*val = ret;
219		return IIO_VAL_INT;
220	case IIO_CHAN_INFO_CALIBSCALE:
221		*val = cm32181->calibscale;
222		return IIO_VAL_INT;
223	case IIO_CHAN_INFO_INT_TIME:
224		*val = 0;
225		ret = cm32181_read_als_it(cm32181, val2);
226		return ret;
227	}
228
229	return -EINVAL;
230}
231
232static int cm32181_write_raw(struct iio_dev *indio_dev,
233			     struct iio_chan_spec const *chan,
234			     int val, int val2, long mask)
235{
236	struct cm32181_chip *cm32181 = iio_priv(indio_dev);
237	int ret;
238
239	switch (mask) {
240	case IIO_CHAN_INFO_CALIBSCALE:
241		cm32181->calibscale = val;
242		return val;
243	case IIO_CHAN_INFO_INT_TIME:
244		ret = cm32181_write_als_it(cm32181, val2);
245		return ret;
246	}
247
248	return -EINVAL;
249}
250
251/**
252 * cm32181_get_it_available() - Get available ALS IT value
253 * @dev:	pointer of struct device.
254 * @attr:	pointer of struct device_attribute.
255 * @buf:	pointer of return string buffer.
256 *
257 * Display the available integration time values by millisecond.
258 *
259 * Return: string length.
260 */
261static ssize_t cm32181_get_it_available(struct device *dev,
262			struct device_attribute *attr, char *buf)
263{
 
264	int i, n, len;
265
266	n = ARRAY_SIZE(als_it_value);
267	for (i = 0, len = 0; i < n; i++)
268		len += sprintf(buf + len, "0.%06u ", als_it_value[i]);
269	return len + sprintf(buf + len, "\n");
270}
271
272static const struct iio_chan_spec cm32181_channels[] = {
273	{
274		.type = IIO_LIGHT,
275		.info_mask_separate =
276			BIT(IIO_CHAN_INFO_PROCESSED) |
277			BIT(IIO_CHAN_INFO_CALIBSCALE) |
278			BIT(IIO_CHAN_INFO_INT_TIME),
279	}
280};
281
282static IIO_DEVICE_ATTR(in_illuminance_integration_time_available,
283			S_IRUGO, cm32181_get_it_available, NULL, 0);
284
285static struct attribute *cm32181_attributes[] = {
286	&iio_dev_attr_in_illuminance_integration_time_available.dev_attr.attr,
287	NULL,
288};
289
290static const struct attribute_group cm32181_attribute_group = {
291	.attrs = cm32181_attributes
292};
293
294static const struct iio_info cm32181_info = {
295	.driver_module		= THIS_MODULE,
296	.read_raw		= &cm32181_read_raw,
297	.write_raw		= &cm32181_write_raw,
298	.attrs			= &cm32181_attribute_group,
299};
300
301static int cm32181_probe(struct i2c_client *client,
302			const struct i2c_device_id *id)
303{
 
304	struct cm32181_chip *cm32181;
305	struct iio_dev *indio_dev;
306	int ret;
307
308	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*cm32181));
309	if (!indio_dev) {
310		dev_err(&client->dev, "devm_iio_device_alloc failed\n");
311		return -ENOMEM;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
312	}
313
314	cm32181 = iio_priv(indio_dev);
315	i2c_set_clientdata(client, indio_dev);
316	cm32181->client = client;
 
317
318	mutex_init(&cm32181->lock);
319	indio_dev->dev.parent = &client->dev;
320	indio_dev->channels = cm32181_channels;
321	indio_dev->num_channels = ARRAY_SIZE(cm32181_channels);
322	indio_dev->info = &cm32181_info;
323	indio_dev->name = id->name;
324	indio_dev->modes = INDIO_DIRECT_MODE;
325
326	ret = cm32181_reg_init(cm32181);
327	if (ret) {
328		dev_err(&client->dev,
329			"%s: register init failed\n",
330			__func__);
331		return ret;
332	}
333
334	ret = devm_iio_device_register(&client->dev, indio_dev);
335	if (ret) {
336		dev_err(&client->dev,
337			"%s: regist device failed\n",
338			__func__);
339		return ret;
340	}
341
342	return 0;
343}
344
345static const struct i2c_device_id cm32181_id[] = {
346	{ "cm32181", 0 },
347	{ }
348};
 
 
 
 
349
350MODULE_DEVICE_TABLE(i2c, cm32181_id);
 
 
 
 
 
 
 
 
 
351
352static const struct of_device_id cm32181_of_match[] = {
 
353	{ .compatible = "capella,cm32181" },
354	{ }
355};
356MODULE_DEVICE_TABLE(of, cm32181_of_match);
357
 
 
 
 
 
 
 
 
358static struct i2c_driver cm32181_driver = {
359	.driver = {
360		.name	= "cm32181",
361		.of_match_table = of_match_ptr(cm32181_of_match),
 
 
362	},
363	.id_table       = cm32181_id,
364	.probe		= cm32181_probe,
365};
366
367module_i2c_driver(cm32181_driver);
368
369MODULE_AUTHOR("Kevin Tsai <ktsai@capellamicro.com>");
370MODULE_DESCRIPTION("CM32181 ambient light sensor driver");
371MODULE_LICENSE("GPL");
v6.2
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright (C) 2013 Capella Microsystems Inc.
  4 * Author: Kevin Tsai <ktsai@capellamicro.com>
 
 
 
 
  5 */
  6
  7#include <linux/acpi.h>
  8#include <linux/delay.h>
  9#include <linux/err.h>
 10#include <linux/i2c.h>
 11#include <linux/mutex.h>
 12#include <linux/module.h>
 13#include <linux/mod_devicetable.h>
 14#include <linux/interrupt.h>
 15#include <linux/regulator/consumer.h>
 16#include <linux/iio/iio.h>
 17#include <linux/iio/sysfs.h>
 18#include <linux/iio/events.h>
 19#include <linux/init.h>
 20
 21/* Registers Address */
 22#define CM32181_REG_ADDR_CMD		0x00
 23#define CM32181_REG_ADDR_WH		0x01
 24#define CM32181_REG_ADDR_WL		0x02
 25#define CM32181_REG_ADDR_TEST		0x03
 26#define CM32181_REG_ADDR_ALS		0x04
 27#define CM32181_REG_ADDR_STATUS		0x06
 28#define CM32181_REG_ADDR_ID		0x07
 29
 30/* Number of Configurable Registers */
 31#define CM32181_CONF_REG_NUM		4
 32
 33/* CMD register */
 34#define CM32181_CMD_ALS_DISABLE		BIT(0)
 35#define CM32181_CMD_ALS_INT_EN		BIT(1)
 36#define CM32181_CMD_ALS_THRES_WINDOW	BIT(2)
 37
 38#define CM32181_CMD_ALS_PERS_SHIFT	4
 39#define CM32181_CMD_ALS_PERS_MASK	(0x03 << CM32181_CMD_ALS_PERS_SHIFT)
 40#define CM32181_CMD_ALS_PERS_DEFAULT	(0x01 << CM32181_CMD_ALS_PERS_SHIFT)
 41
 42#define CM32181_CMD_ALS_IT_SHIFT	6
 43#define CM32181_CMD_ALS_IT_MASK		(0x0F << CM32181_CMD_ALS_IT_SHIFT)
 44#define CM32181_CMD_ALS_IT_DEFAULT	(0x00 << CM32181_CMD_ALS_IT_SHIFT)
 45
 46#define CM32181_CMD_ALS_SM_SHIFT	11
 47#define CM32181_CMD_ALS_SM_MASK		(0x03 << CM32181_CMD_ALS_SM_SHIFT)
 48#define CM32181_CMD_ALS_SM_DEFAULT	(0x01 << CM32181_CMD_ALS_SM_SHIFT)
 49
 50#define CM32181_LUX_PER_BIT		500	/* ALS_SM=01 IT=800ms */
 51#define CM32181_LUX_PER_BIT_RESOLUTION	100000
 52#define CM32181_LUX_PER_BIT_BASE_IT	800000	/* Based on IT=800ms */
 53#define CM32181_CALIBSCALE_DEFAULT	100000
 54#define CM32181_CALIBSCALE_RESOLUTION	100000
 55
 56#define SMBUS_ALERT_RESPONSE_ADDRESS	0x0c
 57
 58/* CPM0 Index 0: device-id (3218 or 32181), 1: Unknown, 2: init_regs_bitmap */
 59#define CPM0_REGS_BITMAP		2
 60#define CPM0_HEADER_SIZE		3
 61
 62/* CPM1 Index 0: lux_per_bit, 1: calibscale, 2: resolution (100000) */
 63#define CPM1_LUX_PER_BIT		0
 64#define CPM1_CALIBSCALE			1
 65#define CPM1_SIZE			3
 66
 67/* CM3218 Family */
 68static const int cm3218_als_it_bits[] = { 0, 1, 2, 3 };
 69static const int cm3218_als_it_values[] = { 100000, 200000, 400000, 800000 };
 70
 71/* CM32181 Family */
 72static const int cm32181_als_it_bits[] = { 12, 8, 0, 1, 2, 3 };
 73static const int cm32181_als_it_values[] = {
 74	25000, 50000, 100000, 200000, 400000, 800000
 75};
 76
 
 
 
 
 77struct cm32181_chip {
 78	struct i2c_client *client;
 79	struct device *dev;
 80	struct mutex lock;
 81	u16 conf_regs[CM32181_CONF_REG_NUM];
 82	unsigned long init_regs_bitmap;
 83	int calibscale;
 84	int lux_per_bit;
 85	int lux_per_bit_base_it;
 86	int num_als_it;
 87	const int *als_it_bits;
 88	const int *als_it_values;
 89};
 90
 91static int cm32181_read_als_it(struct cm32181_chip *cm32181, int *val2);
 92
 93#ifdef CONFIG_ACPI
 94/**
 95 * cm32181_acpi_get_cpm() - Get CPM object from ACPI
 96 * @dev:	pointer of struct device.
 97 * @obj_name:	pointer of ACPI object name.
 98 * @values:	pointer of array for return elements.
 99 * @count:	maximum size of return array.
100 *
101 * Convert ACPI CPM table to array.
102 *
103 * Return: -ENODEV for fail.  Otherwise is number of elements.
104 */
105static int cm32181_acpi_get_cpm(struct device *dev, char *obj_name,
106				u64 *values, int count)
107{
108	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
109	union acpi_object *cpm, *elem;
110	acpi_handle handle;
111	acpi_status status;
112	int i;
113
114	handle = ACPI_HANDLE(dev);
115	if (!handle)
116		return -ENODEV;
117
118	status = acpi_evaluate_object(handle, obj_name, NULL, &buffer);
119	if (ACPI_FAILURE(status)) {
120		dev_err(dev, "object %s not found\n", obj_name);
121		return -ENODEV;
122	}
123
124	cpm = buffer.pointer;
125	if (cpm->package.count > count)
126		dev_warn(dev, "%s table contains %u values, only using first %d values\n",
127			 obj_name, cpm->package.count, count);
128
129	count = min_t(int, cpm->package.count, count);
130	for (i = 0; i < count; i++) {
131		elem = &(cpm->package.elements[i]);
132		values[i] = elem->integer.value;
133	}
134
135	kfree(buffer.pointer);
136
137	return count;
138}
139
140static void cm32181_acpi_parse_cpm_tables(struct cm32181_chip *cm32181)
141{
142	u64 vals[CPM0_HEADER_SIZE + CM32181_CONF_REG_NUM];
143	struct device *dev = cm32181->dev;
144	int i, count;
145
146	count = cm32181_acpi_get_cpm(dev, "CPM0", vals, ARRAY_SIZE(vals));
147	if (count <= CPM0_HEADER_SIZE)
148		return;
149
150	count -= CPM0_HEADER_SIZE;
151
152	cm32181->init_regs_bitmap = vals[CPM0_REGS_BITMAP];
153	cm32181->init_regs_bitmap &= GENMASK(count - 1, 0);
154	for_each_set_bit(i, &cm32181->init_regs_bitmap, count)
155		cm32181->conf_regs[i] =	vals[CPM0_HEADER_SIZE + i];
156
157	count = cm32181_acpi_get_cpm(dev, "CPM1", vals, ARRAY_SIZE(vals));
158	if (count != CPM1_SIZE)
159		return;
160
161	cm32181->lux_per_bit = vals[CPM1_LUX_PER_BIT];
162
163	/* Check for uncalibrated devices */
164	if (vals[CPM1_CALIBSCALE] == CM32181_CALIBSCALE_DEFAULT)
165		return;
166
167	cm32181->calibscale = vals[CPM1_CALIBSCALE];
168	/* CPM1 lux_per_bit is for the current it value */
169	cm32181_read_als_it(cm32181, &cm32181->lux_per_bit_base_it);
170}
171#else
172static void cm32181_acpi_parse_cpm_tables(struct cm32181_chip *cm32181)
173{
174}
175#endif /* CONFIG_ACPI */
176
177/**
178 * cm32181_reg_init() - Initialize CM32181 registers
179 * @cm32181:	pointer of struct cm32181.
180 *
181 * Initialize CM32181 ambient light sensor register to default values.
182 *
183 * Return: 0 for success; otherwise for error code.
184 */
185static int cm32181_reg_init(struct cm32181_chip *cm32181)
186{
187	struct i2c_client *client = cm32181->client;
188	int i;
189	s32 ret;
190
191	ret = i2c_smbus_read_word_data(client, CM32181_REG_ADDR_ID);
192	if (ret < 0)
193		return ret;
194
195	/* check device ID */
196	switch (ret & 0xFF) {
197	case 0x18: /* CM3218 */
198		cm32181->num_als_it = ARRAY_SIZE(cm3218_als_it_bits);
199		cm32181->als_it_bits = cm3218_als_it_bits;
200		cm32181->als_it_values = cm3218_als_it_values;
201		break;
202	case 0x81: /* CM32181 */
203	case 0x82: /* CM32182, fully compat. with CM32181 */
204		cm32181->num_als_it = ARRAY_SIZE(cm32181_als_it_bits);
205		cm32181->als_it_bits = cm32181_als_it_bits;
206		cm32181->als_it_values = cm32181_als_it_values;
207		break;
208	default:
209		return -ENODEV;
210	}
211
212	/* Default Values */
213	cm32181->conf_regs[CM32181_REG_ADDR_CMD] =
214			CM32181_CMD_ALS_IT_DEFAULT | CM32181_CMD_ALS_SM_DEFAULT;
215	cm32181->init_regs_bitmap = BIT(CM32181_REG_ADDR_CMD);
216	cm32181->calibscale = CM32181_CALIBSCALE_DEFAULT;
217	cm32181->lux_per_bit = CM32181_LUX_PER_BIT;
218	cm32181->lux_per_bit_base_it = CM32181_LUX_PER_BIT_BASE_IT;
219
220	if (ACPI_HANDLE(cm32181->dev))
221		cm32181_acpi_parse_cpm_tables(cm32181);
222
223	/* Initialize registers*/
224	for_each_set_bit(i, &cm32181->init_regs_bitmap, CM32181_CONF_REG_NUM) {
225		ret = i2c_smbus_write_word_data(client, i,
226						cm32181->conf_regs[i]);
227		if (ret < 0)
228			return ret;
229	}
230
231	return 0;
232}
233
234/**
235 *  cm32181_read_als_it() - Get sensor integration time (ms)
236 *  @cm32181:	pointer of struct cm32181
237 *  @val2:	pointer of int to load the als_it value.
238 *
239 *  Report the current integration time in milliseconds.
240 *
241 *  Return: IIO_VAL_INT_PLUS_MICRO for success, otherwise -EINVAL.
242 */
243static int cm32181_read_als_it(struct cm32181_chip *cm32181, int *val2)
244{
245	u16 als_it;
246	int i;
247
248	als_it = cm32181->conf_regs[CM32181_REG_ADDR_CMD];
249	als_it &= CM32181_CMD_ALS_IT_MASK;
250	als_it >>= CM32181_CMD_ALS_IT_SHIFT;
251	for (i = 0; i < cm32181->num_als_it; i++) {
252		if (als_it == cm32181->als_it_bits[i]) {
253			*val2 = cm32181->als_it_values[i];
254			return IIO_VAL_INT_PLUS_MICRO;
255		}
256	}
257
258	return -EINVAL;
259}
260
261/**
262 * cm32181_write_als_it() - Write sensor integration time
263 * @cm32181:	pointer of struct cm32181.
264 * @val:	integration time by millisecond.
265 *
266 * Convert integration time (ms) to sensor value.
267 *
268 * Return: i2c_smbus_write_word_data command return value.
269 */
270static int cm32181_write_als_it(struct cm32181_chip *cm32181, int val)
271{
272	struct i2c_client *client = cm32181->client;
273	u16 als_it;
274	int ret, i, n;
275
276	n = cm32181->num_als_it;
277	for (i = 0; i < n; i++)
278		if (val <= cm32181->als_it_values[i])
279			break;
280	if (i >= n)
281		i = n - 1;
282
283	als_it = cm32181->als_it_bits[i];
284	als_it <<= CM32181_CMD_ALS_IT_SHIFT;
285
286	mutex_lock(&cm32181->lock);
287	cm32181->conf_regs[CM32181_REG_ADDR_CMD] &=
288		~CM32181_CMD_ALS_IT_MASK;
289	cm32181->conf_regs[CM32181_REG_ADDR_CMD] |=
290		als_it;
291	ret = i2c_smbus_write_word_data(client, CM32181_REG_ADDR_CMD,
292			cm32181->conf_regs[CM32181_REG_ADDR_CMD]);
293	mutex_unlock(&cm32181->lock);
294
295	return ret;
296}
297
298/**
299 * cm32181_get_lux() - report current lux value
300 * @cm32181:	pointer of struct cm32181.
301 *
302 * Convert sensor raw data to lux.  It depends on integration
303 * time and calibscale variable.
304 *
305 * Return: Positive value is lux, otherwise is error code.
306 */
307static int cm32181_get_lux(struct cm32181_chip *cm32181)
308{
309	struct i2c_client *client = cm32181->client;
310	int ret;
311	int als_it;
312	u64 lux;
313
314	ret = cm32181_read_als_it(cm32181, &als_it);
315	if (ret < 0)
316		return -EINVAL;
317
318	lux = cm32181->lux_per_bit;
319	lux *= cm32181->lux_per_bit_base_it;
320	lux = div_u64(lux, als_it);
321
322	ret = i2c_smbus_read_word_data(client, CM32181_REG_ADDR_ALS);
323	if (ret < 0)
324		return ret;
325
326	lux *= ret;
327	lux *= cm32181->calibscale;
328	lux = div_u64(lux, CM32181_CALIBSCALE_RESOLUTION);
329	lux = div_u64(lux, CM32181_LUX_PER_BIT_RESOLUTION);
330
331	if (lux > 0xFFFF)
332		lux = 0xFFFF;
333
334	return lux;
335}
336
337static int cm32181_read_raw(struct iio_dev *indio_dev,
338			    struct iio_chan_spec const *chan,
339			    int *val, int *val2, long mask)
340{
341	struct cm32181_chip *cm32181 = iio_priv(indio_dev);
342	int ret;
343
344	switch (mask) {
345	case IIO_CHAN_INFO_PROCESSED:
346		ret = cm32181_get_lux(cm32181);
347		if (ret < 0)
348			return ret;
349		*val = ret;
350		return IIO_VAL_INT;
351	case IIO_CHAN_INFO_CALIBSCALE:
352		*val = cm32181->calibscale;
353		return IIO_VAL_INT;
354	case IIO_CHAN_INFO_INT_TIME:
355		*val = 0;
356		ret = cm32181_read_als_it(cm32181, val2);
357		return ret;
358	}
359
360	return -EINVAL;
361}
362
363static int cm32181_write_raw(struct iio_dev *indio_dev,
364			     struct iio_chan_spec const *chan,
365			     int val, int val2, long mask)
366{
367	struct cm32181_chip *cm32181 = iio_priv(indio_dev);
368	int ret;
369
370	switch (mask) {
371	case IIO_CHAN_INFO_CALIBSCALE:
372		cm32181->calibscale = val;
373		return val;
374	case IIO_CHAN_INFO_INT_TIME:
375		ret = cm32181_write_als_it(cm32181, val2);
376		return ret;
377	}
378
379	return -EINVAL;
380}
381
382/**
383 * cm32181_get_it_available() - Get available ALS IT value
384 * @dev:	pointer of struct device.
385 * @attr:	pointer of struct device_attribute.
386 * @buf:	pointer of return string buffer.
387 *
388 * Display the available integration time values by millisecond.
389 *
390 * Return: string length.
391 */
392static ssize_t cm32181_get_it_available(struct device *dev,
393			struct device_attribute *attr, char *buf)
394{
395	struct cm32181_chip *cm32181 = iio_priv(dev_to_iio_dev(dev));
396	int i, n, len;
397
398	n = cm32181->num_als_it;
399	for (i = 0, len = 0; i < n; i++)
400		len += sprintf(buf + len, "0.%06u ", cm32181->als_it_values[i]);
401	return len + sprintf(buf + len, "\n");
402}
403
404static const struct iio_chan_spec cm32181_channels[] = {
405	{
406		.type = IIO_LIGHT,
407		.info_mask_separate =
408			BIT(IIO_CHAN_INFO_PROCESSED) |
409			BIT(IIO_CHAN_INFO_CALIBSCALE) |
410			BIT(IIO_CHAN_INFO_INT_TIME),
411	}
412};
413
414static IIO_DEVICE_ATTR(in_illuminance_integration_time_available,
415			S_IRUGO, cm32181_get_it_available, NULL, 0);
416
417static struct attribute *cm32181_attributes[] = {
418	&iio_dev_attr_in_illuminance_integration_time_available.dev_attr.attr,
419	NULL,
420};
421
422static const struct attribute_group cm32181_attribute_group = {
423	.attrs = cm32181_attributes
424};
425
426static const struct iio_info cm32181_info = {
 
427	.read_raw		= &cm32181_read_raw,
428	.write_raw		= &cm32181_write_raw,
429	.attrs			= &cm32181_attribute_group,
430};
431
432static int cm32181_probe(struct i2c_client *client)
 
433{
434	struct device *dev = &client->dev;
435	struct cm32181_chip *cm32181;
436	struct iio_dev *indio_dev;
437	int ret;
438
439	indio_dev = devm_iio_device_alloc(dev, sizeof(*cm32181));
440	if (!indio_dev)
 
441		return -ENOMEM;
442
443	i2c_set_clientdata(client, indio_dev);
444
445	/*
446	 * Some ACPI systems list 2 I2C resources for the CM3218 sensor, the
447	 * SMBus Alert Response Address (ARA, 0x0c) and the actual I2C address.
448	 * Detect this and take the following step to deal with it:
449	 * 1. When a SMBus Alert capable sensor has an Alert asserted, it will
450	 *    not respond on its actual I2C address. Read a byte from the ARA
451	 *    to clear any pending Alerts.
452	 * 2. Create a "dummy" client for the actual I2C address and
453	 *    use that client to communicate with the sensor.
454	 */
455	if (ACPI_HANDLE(dev) && client->addr == SMBUS_ALERT_RESPONSE_ADDRESS) {
456		struct i2c_board_info board_info = { .type = "dummy" };
457
458		i2c_smbus_read_byte(client);
459
460		client = i2c_acpi_new_device(dev, 1, &board_info);
461		if (IS_ERR(client))
462			return PTR_ERR(client);
463	}
464
465	cm32181 = iio_priv(indio_dev);
 
466	cm32181->client = client;
467	cm32181->dev = dev;
468
469	mutex_init(&cm32181->lock);
 
470	indio_dev->channels = cm32181_channels;
471	indio_dev->num_channels = ARRAY_SIZE(cm32181_channels);
472	indio_dev->info = &cm32181_info;
473	indio_dev->name = dev_name(dev);
474	indio_dev->modes = INDIO_DIRECT_MODE;
475
476	ret = cm32181_reg_init(cm32181);
477	if (ret) {
478		dev_err(dev, "%s: register init failed\n", __func__);
 
 
479		return ret;
480	}
481
482	ret = devm_iio_device_register(dev, indio_dev);
483	if (ret) {
484		dev_err(dev, "%s: regist device failed\n", __func__);
 
 
485		return ret;
486	}
487
488	return 0;
489}
490
491static int cm32181_suspend(struct device *dev)
492{
493	struct cm32181_chip *cm32181 = iio_priv(dev_get_drvdata(dev));
494	struct i2c_client *client = cm32181->client;
495
496	return i2c_smbus_write_word_data(client, CM32181_REG_ADDR_CMD,
497					 CM32181_CMD_ALS_DISABLE);
498}
499
500static int cm32181_resume(struct device *dev)
501{
502	struct cm32181_chip *cm32181 = iio_priv(dev_get_drvdata(dev));
503	struct i2c_client *client = cm32181->client;
504
505	return i2c_smbus_write_word_data(client, CM32181_REG_ADDR_CMD,
506					 cm32181->conf_regs[CM32181_REG_ADDR_CMD]);
507}
508
509static DEFINE_SIMPLE_DEV_PM_OPS(cm32181_pm_ops, cm32181_suspend, cm32181_resume);
510
511static const struct of_device_id cm32181_of_match[] = {
512	{ .compatible = "capella,cm3218" },
513	{ .compatible = "capella,cm32181" },
514	{ }
515};
516MODULE_DEVICE_TABLE(of, cm32181_of_match);
517
518#ifdef CONFIG_ACPI
519static const struct acpi_device_id cm32181_acpi_match[] = {
520	{ "CPLM3218", 0 },
521	{ }
522};
523MODULE_DEVICE_TABLE(acpi, cm32181_acpi_match);
524#endif
525
526static struct i2c_driver cm32181_driver = {
527	.driver = {
528		.name	= "cm32181",
529		.acpi_match_table = ACPI_PTR(cm32181_acpi_match),
530		.of_match_table = cm32181_of_match,
531		.pm = pm_sleep_ptr(&cm32181_pm_ops),
532	},
533	.probe_new	= cm32181_probe,
 
534};
535
536module_i2c_driver(cm32181_driver);
537
538MODULE_AUTHOR("Kevin Tsai <ktsai@capellamicro.com>");
539MODULE_DESCRIPTION("CM32181 ambient light sensor driver");
540MODULE_LICENSE("GPL");