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2024-10-09 244b2c5ca8b14627e4a17755e5922221e121c771 
 kernel/drivers/iio/adc/ltc2497.c
....@@ -1,34 +1,24 @@
1
+// SPDX-License-Identifier: GPL-2.0-only
12 /*
23  * ltc2497.c - Driver for Analog Devices/Linear Technology LTC2497 ADC
34  *
45  * Copyright (C) 2017 Analog Devices Inc.
56  *
6
- * Licensed under the GPL-2.
7
- *
87  * Datasheet: http://cds.linear.com/docs/en/datasheet/2497fd.pdf
98  */
109 
11
-#include <linux/delay.h>
1210 #include <linux/i2c.h>
1311 #include <linux/iio/iio.h>
1412 #include <linux/iio/driver.h>
15
-#include <linux/iio/sysfs.h>
1613 #include <linux/module.h>
17
-#include <linux/of.h>
18
-#include <linux/regulator/consumer.h>
14
+#include <linux/mod_devicetable.h>
1915 
20
-#define LTC2497_ENABLE			0xA0
21
-#define LTC2497_SGL			BIT(4)
22
-#define LTC2497_DIFF			0
23
-#define LTC2497_SIGN			BIT(3)
24
-#define LTC2497_CONFIG_DEFAULT		LTC2497_ENABLE
25
-#define LTC2497_CONVERSION_TIME_MS	150ULL
16
+#include "ltc2497.h"
2617 
27
-struct ltc2497_st {
18
+struct ltc2497_driverdata {
19
+	/* this must be the first member */
20
+	struct ltc2497core_driverdata common_ddata;
2821 	struct i2c_client *client;
29
-	struct regulator *ref;
30
-	ktime_t	time_prev;
31
-	u8 addr_prev;
3222 	/*
3323 	 * DMA (thus cache coherency maintenance) requires the
3424 	 * transfer buffers to live in their own cache lines.
....@@ -36,232 +26,72 @@
3626 	__be32 buf ____cacheline_aligned;
3727 };
3828 
39
-static int ltc2497_wait_conv(struct ltc2497_st *st)
29
+static int ltc2497_result_and_measure(struct ltc2497core_driverdata *ddata,
30
+				      u8 address, int *val)
4031 {
41
-	s64 time_elapsed;
42
-
43
-	time_elapsed = ktime_ms_delta(ktime_get(), st->time_prev);
44
-
45
-	if (time_elapsed < LTC2497_CONVERSION_TIME_MS) {
46
-		/* delay if conversion time not passed
47
-		 * since last read or write
48
-		 */
49
-		if (msleep_interruptible(
50
-		    LTC2497_CONVERSION_TIME_MS - time_elapsed))
51
-			return -ERESTARTSYS;
52
-
53
-		return 0;
54
-	}
55
-
56
-	if (time_elapsed - LTC2497_CONVERSION_TIME_MS <= 0) {
57
-		/* We're in automatic mode -
58
-		 * so the last reading is stil not outdated
59
-		 */
60
-		return 0;
61
-	}
62
-
63
-	return 1;
64
-}
65
-
66
-static int ltc2497_read(struct ltc2497_st *st, u8 address, int *val)
67
-{
68
-	struct i2c_client *client = st->client;
32
+	struct ltc2497_driverdata *st =
33
+		container_of(ddata, struct ltc2497_driverdata, common_ddata);
6934 	int ret;
7035 
71
-	ret = ltc2497_wait_conv(st);
72
-	if (ret < 0)
73
-		return ret;
74
-
75
-	if (ret || st->addr_prev != address) {
76
-		ret = i2c_smbus_write_byte(st->client,
77
-					   LTC2497_ENABLE | address);
78
-		if (ret < 0)
36
+	if (val) {
37
+		ret = i2c_master_recv(st->client, (char *)&st->buf, 3);
38
+		if (ret < 0) {
39
+			dev_err(&st->client->dev, "i2c_master_recv failed\n");
7940 			return ret;
80
-		st->addr_prev = address;
81
-		if (msleep_interruptible(LTC2497_CONVERSION_TIME_MS))
82
-			return -ERESTARTSYS;
83
-	}
84
-	ret = i2c_master_recv(client, (char *)&st->buf, 3);
85
-	if (ret < 0)  {
86
-		dev_err(&client->dev, "i2c_master_recv failed\n");
87
-		return ret;
88
-	}
89
-	st->time_prev = ktime_get();
41
+		}
9042 
91
-	/* convert and shift the result,
92
-	 * and finally convert from offset binary to signed integer
93
-	 */
94
-	*val = (be32_to_cpu(st->buf) >> 14) - (1 << 17);
43
+		*val = (be32_to_cpu(st->buf) >> 14) - (1 << 17);
9544 
45
+		/*
46
+		 * The part started a new conversion at the end of the above i2c
47
+		 * transfer, so if the address didn't change since the last call
48
+		 * everything is fine and we can return early.
49
+		 * If not (which should only happen when some sort of bulk
50
+		 * conversion is implemented) we have to program the new
51
+		 * address. Note that this probably fails as the conversion that
52
+		 * was triggered above is like not complete yet and the two
53
+		 * operations have to be done in a single transfer.
54
+		 */
55
+		if (ddata->addr_prev == address)
56
+			return 0;
57
+	}
58
+
59
+	ret = i2c_smbus_write_byte(st->client,
60
+				   LTC2497_ENABLE | address);
61
+	if (ret)
62
+		dev_err(&st->client->dev, "i2c transfer failed: %pe\n",
63
+			ERR_PTR(ret));
9664 	return ret;
9765 }
98
-
99
-static int ltc2497_read_raw(struct iio_dev *indio_dev,
100
-			    struct iio_chan_spec const *chan,
101
-			    int *val, int *val2, long mask)
102
-{
103
-	struct ltc2497_st *st = iio_priv(indio_dev);
104
-	int ret;
105
-
106
-	switch (mask) {
107
-	case IIO_CHAN_INFO_RAW:
108
-		mutex_lock(&indio_dev->mlock);
109
-		ret = ltc2497_read(st, chan->address, val);
110
-		mutex_unlock(&indio_dev->mlock);
111
-		if (ret < 0)
112
-			return ret;
113
-
114
-		return IIO_VAL_INT;
115
-
116
-	case IIO_CHAN_INFO_SCALE:
117
-		ret = regulator_get_voltage(st->ref);
118
-		if (ret < 0)
119
-			return ret;
120
-
121
-		*val = ret / 1000;
122
-		*val2 = 17;
123
-
124
-		return IIO_VAL_FRACTIONAL_LOG2;
125
-
126
-	default:
127
-		return -EINVAL;
128
-	}
129
-}
130
-
131
-#define LTC2497_CHAN(_chan, _addr, _ds_name) { \
132
-	.type = IIO_VOLTAGE, \
133
-	.indexed = 1, \
134
-	.channel = (_chan), \
135
-	.address = (_addr | (_chan / 2) | ((_chan & 1) ? LTC2497_SIGN : 0)), \
136
-	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
137
-	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
138
-	.datasheet_name = (_ds_name), \
139
-}
140
-
141
-#define LTC2497_CHAN_DIFF(_chan, _addr) { \
142
-	.type = IIO_VOLTAGE, \
143
-	.indexed = 1, \
144
-	.channel = (_chan) * 2 + ((_addr) & LTC2497_SIGN ? 1 : 0), \
145
-	.channel2 = (_chan) * 2 + ((_addr) & LTC2497_SIGN ? 0 : 1),\
146
-	.address = (_addr | _chan), \
147
-	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
148
-	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
149
-	.differential = 1, \
150
-}
151
-
152
-static const struct iio_chan_spec ltc2497_channel[] = {
153
-	LTC2497_CHAN(0, LTC2497_SGL, "CH0"),
154
-	LTC2497_CHAN(1, LTC2497_SGL, "CH1"),
155
-	LTC2497_CHAN(2, LTC2497_SGL, "CH2"),
156
-	LTC2497_CHAN(3, LTC2497_SGL, "CH3"),
157
-	LTC2497_CHAN(4, LTC2497_SGL, "CH4"),
158
-	LTC2497_CHAN(5, LTC2497_SGL, "CH5"),
159
-	LTC2497_CHAN(6, LTC2497_SGL, "CH6"),
160
-	LTC2497_CHAN(7, LTC2497_SGL, "CH7"),
161
-	LTC2497_CHAN(8, LTC2497_SGL, "CH8"),
162
-	LTC2497_CHAN(9, LTC2497_SGL, "CH9"),
163
-	LTC2497_CHAN(10, LTC2497_SGL, "CH10"),
164
-	LTC2497_CHAN(11, LTC2497_SGL, "CH11"),
165
-	LTC2497_CHAN(12, LTC2497_SGL, "CH12"),
166
-	LTC2497_CHAN(13, LTC2497_SGL, "CH13"),
167
-	LTC2497_CHAN(14, LTC2497_SGL, "CH14"),
168
-	LTC2497_CHAN(15, LTC2497_SGL, "CH15"),
169
-	LTC2497_CHAN_DIFF(0, LTC2497_DIFF),
170
-	LTC2497_CHAN_DIFF(1, LTC2497_DIFF),
171
-	LTC2497_CHAN_DIFF(2, LTC2497_DIFF),
172
-	LTC2497_CHAN_DIFF(3, LTC2497_DIFF),
173
-	LTC2497_CHAN_DIFF(4, LTC2497_DIFF),
174
-	LTC2497_CHAN_DIFF(5, LTC2497_DIFF),
175
-	LTC2497_CHAN_DIFF(6, LTC2497_DIFF),
176
-	LTC2497_CHAN_DIFF(7, LTC2497_DIFF),
177
-	LTC2497_CHAN_DIFF(0, LTC2497_DIFF | LTC2497_SIGN),
178
-	LTC2497_CHAN_DIFF(1, LTC2497_DIFF | LTC2497_SIGN),
179
-	LTC2497_CHAN_DIFF(2, LTC2497_DIFF | LTC2497_SIGN),
180
-	LTC2497_CHAN_DIFF(3, LTC2497_DIFF | LTC2497_SIGN),
181
-	LTC2497_CHAN_DIFF(4, LTC2497_DIFF | LTC2497_SIGN),
182
-	LTC2497_CHAN_DIFF(5, LTC2497_DIFF | LTC2497_SIGN),
183
-	LTC2497_CHAN_DIFF(6, LTC2497_DIFF | LTC2497_SIGN),
184
-	LTC2497_CHAN_DIFF(7, LTC2497_DIFF | LTC2497_SIGN),
185
-};
186
-
187
-static const struct iio_info ltc2497_info = {
188
-	.read_raw = ltc2497_read_raw,
189
-};
19066 
19167 static int ltc2497_probe(struct i2c_client *client,
19268 			 const struct i2c_device_id *id)
19369 {
19470 	struct iio_dev *indio_dev;
195
-	struct ltc2497_st *st;
196
-	struct iio_map *plat_data;
197
-	int ret;
71
+	struct ltc2497_driverdata *st;
72
+	struct device *dev = &client->dev;
19873 
19974 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
20075 				     I2C_FUNC_SMBUS_WRITE_BYTE))
20176 		return -EOPNOTSUPP;
20277 
203
-	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
78
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
20479 	if (!indio_dev)
20580 		return -ENOMEM;
20681 
20782 	st = iio_priv(indio_dev);
20883 	i2c_set_clientdata(client, indio_dev);
20984 	st->client = client;
85
+	st->common_ddata.result_and_measure = ltc2497_result_and_measure;
21086 
211
-	indio_dev->dev.parent = &client->dev;
212
-	indio_dev->name = id->name;
213
-	indio_dev->info = &ltc2497_info;
214
-	indio_dev->modes = INDIO_DIRECT_MODE;
215
-	indio_dev->channels = ltc2497_channel;
216
-	indio_dev->num_channels = ARRAY_SIZE(ltc2497_channel);
217
-
218
-	st->ref = devm_regulator_get(&client->dev, "vref");
219
-	if (IS_ERR(st->ref))
220
-		return PTR_ERR(st->ref);
221
-
222
-	ret = regulator_enable(st->ref);
223
-	if (ret < 0)
224
-		return ret;
225
-
226
-	if (client->dev.platform_data) {
227
-		plat_data = ((struct iio_map *)client->dev.platform_data);
228
-		ret = iio_map_array_register(indio_dev, plat_data);
229
-		if (ret) {
230
-			dev_err(&indio_dev->dev, "iio map err: %d\n", ret);
231
-			goto err_regulator_disable;
232
-		}
233
-	}
234
-
235
-	ret = i2c_smbus_write_byte(st->client, LTC2497_CONFIG_DEFAULT);
236
-	if (ret < 0)
237
-		goto err_array_unregister;
238
-
239
-	st->addr_prev = LTC2497_CONFIG_DEFAULT;
240
-	st->time_prev = ktime_get();
241
-
242
-	ret = iio_device_register(indio_dev);
243
-	if (ret < 0)
244
-		goto err_array_unregister;
245
-
246
-	return 0;
247
-
248
-err_array_unregister:
249
-	iio_map_array_unregister(indio_dev);
250
-
251
-err_regulator_disable:
252
-	regulator_disable(st->ref);
253
-
254
-	return ret;
87
+	return ltc2497core_probe(dev, indio_dev);
25588 }
25689 
25790 static int ltc2497_remove(struct i2c_client *client)
25891 {
25992 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
260
-	struct ltc2497_st *st = iio_priv(indio_dev);
26193 
262
-	iio_map_array_unregister(indio_dev);
263
-	iio_device_unregister(indio_dev);
264
-	regulator_disable(st->ref);
94
+	ltc2497core_remove(indio_dev);
26595 
26696 	return 0;
26797 }
....@@ -281,7 +111,7 @@
281111 static struct i2c_driver ltc2497_driver = {
282112 	.driver = {
283113 		.name = "ltc2497",
284
-		.of_match_table = of_match_ptr(ltc2497_of_match),
114
+		.of_match_table = ltc2497_of_match,
285115 	},
286116 	.probe = ltc2497_probe,
287117 	.remove = ltc2497_remove,