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19#include <linux/delay.h>
20#include <linux/device.h>
21#include <linux/err.h>
22#include <linux/interrupt.h>
23#include <linux/iio/iio.h>
24#include <linux/iio/sysfs.h>
25#include <linux/iio/buffer.h>
26#include <linux/iio/trigger_consumer.h>
27#include <linux/iio/triggered_buffer.h>
28#include <linux/kernel.h>
29#include <linux/module.h>
30#include <linux/regulator/consumer.h>
31#include <linux/slab.h>
32#include <linux/spi/spi.h>
33#include <linux/sysfs.h>
34
35struct tlc4541_state {
36 struct spi_device *spi;
37 struct regulator *reg;
38 struct spi_transfer scan_single_xfer[3];
39 struct spi_message scan_single_msg;
40
41
42
43
44
45
46
47 __be16 rx_buf[8] ____cacheline_aligned;
48};
49
50struct tlc4541_chip_info {
51 const struct iio_chan_spec *channels;
52 unsigned int num_channels;
53};
54
55enum tlc4541_id {
56 TLC3541,
57 TLC4541,
58};
59
60#define TLC4541_V_CHAN(bits, bitshift) { \
61 .type = IIO_VOLTAGE, \
62 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
63 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
64 .scan_type = { \
65 .sign = 'u', \
66 .realbits = (bits), \
67 .storagebits = 16, \
68 .shift = (bitshift), \
69 .endianness = IIO_BE, \
70 }, \
71 }
72
73#define DECLARE_TLC4541_CHANNELS(name, bits, bitshift) \
74const struct iio_chan_spec name ## _channels[] = { \
75 TLC4541_V_CHAN(bits, bitshift), \
76 IIO_CHAN_SOFT_TIMESTAMP(1), \
77}
78
79static DECLARE_TLC4541_CHANNELS(tlc3541, 14, 2);
80static DECLARE_TLC4541_CHANNELS(tlc4541, 16, 0);
81
82static const struct tlc4541_chip_info tlc4541_chip_info[] = {
83 [TLC3541] = {
84 .channels = tlc3541_channels,
85 .num_channels = ARRAY_SIZE(tlc3541_channels),
86 },
87 [TLC4541] = {
88 .channels = tlc4541_channels,
89 .num_channels = ARRAY_SIZE(tlc4541_channels),
90 },
91};
92
93static irqreturn_t tlc4541_trigger_handler(int irq, void *p)
94{
95 struct iio_poll_func *pf = p;
96 struct iio_dev *indio_dev = pf->indio_dev;
97 struct tlc4541_state *st = iio_priv(indio_dev);
98 int ret;
99
100 ret = spi_sync(st->spi, &st->scan_single_msg);
101 if (ret < 0)
102 goto done;
103
104 iio_push_to_buffers_with_timestamp(indio_dev, st->rx_buf,
105 iio_get_time_ns(indio_dev));
106
107done:
108 iio_trigger_notify_done(indio_dev->trig);
109 return IRQ_HANDLED;
110}
111
112static int tlc4541_get_range(struct tlc4541_state *st)
113{
114 int vref;
115
116 vref = regulator_get_voltage(st->reg);
117 if (vref < 0)
118 return vref;
119
120 vref /= 1000;
121
122 return vref;
123}
124
125static int tlc4541_read_raw(struct iio_dev *indio_dev,
126 struct iio_chan_spec const *chan,
127 int *val,
128 int *val2,
129 long m)
130{
131 int ret = 0;
132 struct tlc4541_state *st = iio_priv(indio_dev);
133
134 switch (m) {
135 case IIO_CHAN_INFO_RAW:
136 ret = iio_device_claim_direct_mode(indio_dev);
137 if (ret)
138 return ret;
139 ret = spi_sync(st->spi, &st->scan_single_msg);
140 iio_device_release_direct_mode(indio_dev);
141 if (ret < 0)
142 return ret;
143 *val = be16_to_cpu(st->rx_buf[0]);
144 *val = *val >> chan->scan_type.shift;
145 *val &= GENMASK(chan->scan_type.realbits - 1, 0);
146 return IIO_VAL_INT;
147 case IIO_CHAN_INFO_SCALE:
148 ret = tlc4541_get_range(st);
149 if (ret < 0)
150 return ret;
151 *val = ret;
152 *val2 = chan->scan_type.realbits;
153 return IIO_VAL_FRACTIONAL_LOG2;
154 }
155 return -EINVAL;
156}
157
158static const struct iio_info tlc4541_info = {
159 .read_raw = &tlc4541_read_raw,
160};
161
162static int tlc4541_probe(struct spi_device *spi)
163{
164 struct tlc4541_state *st;
165 struct iio_dev *indio_dev;
166 const struct tlc4541_chip_info *info;
167 int ret;
168 int8_t device_init = 0;
169
170 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
171 if (indio_dev == NULL)
172 return -ENOMEM;
173
174 st = iio_priv(indio_dev);
175
176 spi_set_drvdata(spi, indio_dev);
177
178 st->spi = spi;
179
180 info = &tlc4541_chip_info[spi_get_device_id(spi)->driver_data];
181
182 indio_dev->name = spi_get_device_id(spi)->name;
183 indio_dev->dev.parent = &spi->dev;
184 indio_dev->modes = INDIO_DIRECT_MODE;
185 indio_dev->channels = info->channels;
186 indio_dev->num_channels = info->num_channels;
187 indio_dev->info = &tlc4541_info;
188
189
190 spi_write(spi, &device_init, 1);
191
192
193 st->scan_single_xfer[0].rx_buf = &st->rx_buf[0];
194 st->scan_single_xfer[0].len = 3;
195 st->scan_single_xfer[1].delay_usecs = 3;
196 st->scan_single_xfer[2].rx_buf = &st->rx_buf[0];
197 st->scan_single_xfer[2].len = 2;
198
199 spi_message_init_with_transfers(&st->scan_single_msg,
200 st->scan_single_xfer, 3);
201
202 st->reg = devm_regulator_get(&spi->dev, "vref");
203 if (IS_ERR(st->reg))
204 return PTR_ERR(st->reg);
205
206 ret = regulator_enable(st->reg);
207 if (ret)
208 return ret;
209
210 ret = iio_triggered_buffer_setup(indio_dev, NULL,
211 &tlc4541_trigger_handler, NULL);
212 if (ret)
213 goto error_disable_reg;
214
215 ret = iio_device_register(indio_dev);
216 if (ret)
217 goto error_cleanup_buffer;
218
219 return 0;
220
221error_cleanup_buffer:
222 iio_triggered_buffer_cleanup(indio_dev);
223error_disable_reg:
224 regulator_disable(st->reg);
225
226 return ret;
227}
228
229static int tlc4541_remove(struct spi_device *spi)
230{
231 struct iio_dev *indio_dev = spi_get_drvdata(spi);
232 struct tlc4541_state *st = iio_priv(indio_dev);
233
234 iio_device_unregister(indio_dev);
235 iio_triggered_buffer_cleanup(indio_dev);
236 regulator_disable(st->reg);
237
238 return 0;
239}
240
241#ifdef CONFIG_OF
242static const struct of_device_id tlc4541_dt_ids[] = {
243 { .compatible = "ti,tlc3541", },
244 { .compatible = "ti,tlc4541", },
245 {}
246};
247MODULE_DEVICE_TABLE(of, tlc4541_dt_ids);
248#endif
249
250static const struct spi_device_id tlc4541_id[] = {
251 {"tlc3541", TLC3541},
252 {"tlc4541", TLC4541},
253 {}
254};
255MODULE_DEVICE_TABLE(spi, tlc4541_id);
256
257static struct spi_driver tlc4541_driver = {
258 .driver = {
259 .name = "tlc4541",
260 .of_match_table = of_match_ptr(tlc4541_dt_ids),
261 },
262 .probe = tlc4541_probe,
263 .remove = tlc4541_remove,
264 .id_table = tlc4541_id,
265};
266module_spi_driver(tlc4541_driver);
267
268MODULE_AUTHOR("Phil Reid <preid@electromag.com.au>");
269MODULE_DESCRIPTION("Texas Instruments TLC4541 ADC");
270MODULE_LICENSE("GPL v2");
271
