1/*
2 * AD5624R, AD5644R, AD5664R Digital to analog convertors spi driver
3 *
4 * Copyright 2010-2011 Analog Devices Inc.
5 *
6 * Licensed under the GPL-2.
7 */
8
9#include <linux/interrupt.h>
10#include <linux/fs.h>
11#include <linux/device.h>
12#include <linux/kernel.h>
13#include <linux/spi/spi.h>
14#include <linux/slab.h>
15#include <linux/sysfs.h>
16#include <linux/regulator/consumer.h>
17#include <linux/module.h>
18
19#include <linux/iio/iio.h>
20#include <linux/iio/sysfs.h>
21
22#include "ad5624r.h"
23
24static int ad5624r_spi_write(struct spi_device *spi,
25			     u8 cmd, u8 addr, u16 val, u8 shift)
26{
27	u32 data;
28	u8 msg[3];
29
30	/*
31	 * The input shift register is 24 bits wide. The first two bits are
32	 * don't care bits. The next three are the command bits, C2 to C0,
33	 * followed by the 3-bit DAC address, A2 to A0, and then the
34	 * 16-, 14-, 12-bit data-word. The data-word comprises the 16-,
35	 * 14-, 12-bit input code followed by 0, 2, or 4 don't care bits,
36	 * for the AD5664R, AD5644R, and AD5624R, respectively.
37	 */
38	data = (0 << 22) | (cmd << 19) | (addr << 16) | (val << shift);
39	msg[0] = data >> 16;
40	msg[1] = data >> 8;
41	msg[2] = data;
42
43	return spi_write(spi, msg, 3);
44}
45
46static int ad5624r_read_raw(struct iio_dev *indio_dev,
47			   struct iio_chan_spec const *chan,
48			   int *val,
49			   int *val2,
50			   long m)
51{
52	struct ad5624r_state *st = iio_priv(indio_dev);
53
54	switch (m) {
55	case IIO_CHAN_INFO_SCALE:
56		*val = st->vref_mv;
57		*val2 = chan->scan_type.realbits;
58		return IIO_VAL_FRACTIONAL_LOG2;
59	}
60	return -EINVAL;
61}
62
63static int ad5624r_write_raw(struct iio_dev *indio_dev,
64			       struct iio_chan_spec const *chan,
65			       int val,
66			       int val2,
67			       long mask)
68{
69	struct ad5624r_state *st = iio_priv(indio_dev);
70
71	switch (mask) {
72	case IIO_CHAN_INFO_RAW:
73		if (val >= (1 << chan->scan_type.realbits) || val < 0)
74			return -EINVAL;
75
76		return ad5624r_spi_write(st->us,
77				AD5624R_CMD_WRITE_INPUT_N_UPDATE_N,
78				chan->address, val,
79				chan->scan_type.shift);
80	default:
81		return -EINVAL;
82	}
83}
84
85static const char * const ad5624r_powerdown_modes[] = {
86	"1kohm_to_gnd",
87	"100kohm_to_gnd",
88	"three_state"
89};
90
91static int ad5624r_get_powerdown_mode(struct iio_dev *indio_dev,
92	const struct iio_chan_spec *chan)
93{
94	struct ad5624r_state *st = iio_priv(indio_dev);
95
96	return st->pwr_down_mode;
97}
98
99static int ad5624r_set_powerdown_mode(struct iio_dev *indio_dev,
100	const struct iio_chan_spec *chan, unsigned int mode)
101{
102	struct ad5624r_state *st = iio_priv(indio_dev);
103
104	st->pwr_down_mode = mode;
105
106	return 0;
107}
108
109static const struct iio_enum ad5624r_powerdown_mode_enum = {
110	.items = ad5624r_powerdown_modes,
111	.num_items = ARRAY_SIZE(ad5624r_powerdown_modes),
112	.get = ad5624r_get_powerdown_mode,
113	.set = ad5624r_set_powerdown_mode,
114};
115
116static ssize_t ad5624r_read_dac_powerdown(struct iio_dev *indio_dev,
117	uintptr_t private, const struct iio_chan_spec *chan, char *buf)
118{
119	struct ad5624r_state *st = iio_priv(indio_dev);
120
121	return sprintf(buf, "%d\n",
122			!!(st->pwr_down_mask & (1 << chan->channel)));
123}
124
125static ssize_t ad5624r_write_dac_powerdown(struct iio_dev *indio_dev,
126	uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
127	size_t len)
128{
129	bool pwr_down;
130	int ret;
131	struct ad5624r_state *st = iio_priv(indio_dev);
132
133	ret = strtobool(buf, &pwr_down);
134	if (ret)
135		return ret;
136
137	if (pwr_down)
138		st->pwr_down_mask |= (1 << chan->channel);
139	else
140		st->pwr_down_mask &= ~(1 << chan->channel);
141
142	ret = ad5624r_spi_write(st->us, AD5624R_CMD_POWERDOWN_DAC, 0,
143				(st->pwr_down_mode << 4) |
144				st->pwr_down_mask, 16);
145
146	return ret ? ret : len;
147}
148
149static const struct iio_info ad5624r_info = {
150	.write_raw = ad5624r_write_raw,
151	.read_raw = ad5624r_read_raw,
152	.driver_module = THIS_MODULE,
153};
154
155static const struct iio_chan_spec_ext_info ad5624r_ext_info[] = {
156	{
157		.name = "powerdown",
158		.read = ad5624r_read_dac_powerdown,
159		.write = ad5624r_write_dac_powerdown,
160		.shared = IIO_SEPARATE,
161	},
162	IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE,
163		 &ad5624r_powerdown_mode_enum),
164	IIO_ENUM_AVAILABLE("powerdown_mode", &ad5624r_powerdown_mode_enum),
165	{ },
166};
167
168#define AD5624R_CHANNEL(_chan, _bits) { \
169	.type = IIO_VOLTAGE, \
170	.indexed = 1, \
171	.output = 1, \
172	.channel = (_chan), \
173	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
174	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
175	.address = (_chan), \
176	.scan_type = { \
177		.sign = 'u', \
178		.realbits = (_bits), \
179		.storagebits = 16, \
180		.shift = 16 - (_bits), \
181	}, \
182	.ext_info = ad5624r_ext_info, \
183}
184
185#define DECLARE_AD5624R_CHANNELS(_name, _bits) \
186	const struct iio_chan_spec _name##_channels[] = { \
187		AD5624R_CHANNEL(0, _bits), \
188		AD5624R_CHANNEL(1, _bits), \
189		AD5624R_CHANNEL(2, _bits), \
190		AD5624R_CHANNEL(3, _bits), \
191}
192
193static DECLARE_AD5624R_CHANNELS(ad5624r, 12);
194static DECLARE_AD5624R_CHANNELS(ad5644r, 14);
195static DECLARE_AD5624R_CHANNELS(ad5664r, 16);
196
197static const struct ad5624r_chip_info ad5624r_chip_info_tbl[] = {
198	[ID_AD5624R3] = {
199		.channels = ad5624r_channels,
200		.int_vref_mv = 1250,
201	},
202	[ID_AD5624R5] = {
203		.channels = ad5624r_channels,
204		.int_vref_mv = 2500,
205	},
206	[ID_AD5644R3] = {
207		.channels = ad5644r_channels,
208		.int_vref_mv = 1250,
209	},
210	[ID_AD5644R5] = {
211		.channels = ad5644r_channels,
212		.int_vref_mv = 2500,
213	},
214	[ID_AD5664R3] = {
215		.channels = ad5664r_channels,
216		.int_vref_mv = 1250,
217	},
218	[ID_AD5664R5] = {
219		.channels = ad5664r_channels,
220		.int_vref_mv = 2500,
221	},
222};
223
224static int ad5624r_probe(struct spi_device *spi)
225{
226	struct ad5624r_state *st;
227	struct iio_dev *indio_dev;
228	int ret, voltage_uv = 0;
229
230	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
231	if (!indio_dev)
232		return -ENOMEM;
233	st = iio_priv(indio_dev);
234	st->reg = devm_regulator_get(&spi->dev, "vcc");
235	if (!IS_ERR(st->reg)) {
236		ret = regulator_enable(st->reg);
237		if (ret)
238			return ret;
239
240		ret = regulator_get_voltage(st->reg);
241		if (ret < 0)
242			goto error_disable_reg;
243
244		voltage_uv = ret;
245	}
246
247	spi_set_drvdata(spi, indio_dev);
248	st->chip_info =
249		&ad5624r_chip_info_tbl[spi_get_device_id(spi)->driver_data];
250
251	if (voltage_uv)
252		st->vref_mv = voltage_uv / 1000;
253	else
254		st->vref_mv = st->chip_info->int_vref_mv;
255
256	st->us = spi;
257
258	indio_dev->dev.parent = &spi->dev;
259	indio_dev->name = spi_get_device_id(spi)->name;
260	indio_dev->info = &ad5624r_info;
261	indio_dev->modes = INDIO_DIRECT_MODE;
262	indio_dev->channels = st->chip_info->channels;
263	indio_dev->num_channels = AD5624R_DAC_CHANNELS;
264
265	ret = ad5624r_spi_write(spi, AD5624R_CMD_INTERNAL_REFER_SETUP, 0,
266				!!voltage_uv, 16);
267	if (ret)
268		goto error_disable_reg;
269
270	ret = iio_device_register(indio_dev);
271	if (ret)
272		goto error_disable_reg;
273
274	return 0;
275
276error_disable_reg:
277	if (!IS_ERR(st->reg))
278		regulator_disable(st->reg);
279
280	return ret;
281}
282
283static int ad5624r_remove(struct spi_device *spi)
284{
285	struct iio_dev *indio_dev = spi_get_drvdata(spi);
286	struct ad5624r_state *st = iio_priv(indio_dev);
287
288	iio_device_unregister(indio_dev);
289	if (!IS_ERR(st->reg))
290		regulator_disable(st->reg);
291
292	return 0;
293}
294
295static const struct spi_device_id ad5624r_id[] = {
296	{"ad5624r3", ID_AD5624R3},
297	{"ad5644r3", ID_AD5644R3},
298	{"ad5664r3", ID_AD5664R3},
299	{"ad5624r5", ID_AD5624R5},
300	{"ad5644r5", ID_AD5644R5},
301	{"ad5664r5", ID_AD5664R5},
302	{}
303};
304MODULE_DEVICE_TABLE(spi, ad5624r_id);
305
306static struct spi_driver ad5624r_driver = {
307	.driver = {
308		   .name = "ad5624r",
309		   },
310	.probe = ad5624r_probe,
311	.remove = ad5624r_remove,
312	.id_table = ad5624r_id,
313};
314module_spi_driver(ad5624r_driver);
315
316MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
317MODULE_DESCRIPTION("Analog Devices AD5624/44/64R DAC spi driver");
318MODULE_LICENSE("GPL v2");
319