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55b951e7 EM |
1 | /* |
2 | * max1111.c - +2.7V, Low-Power, Multichannel, Serial 8-bit ADCs | |
3 | * | |
4 | * Based on arch/arm/mach-pxa/corgi_ssp.c | |
5 | * | |
6 | * Copyright (C) 2004-2005 Richard Purdie | |
7 | * | |
8 | * Copyright (C) 2008 Marvell International Ltd. | |
91c8eabe | 9 | * Eric Miao <eric.miao@marvell.com> |
55b951e7 EM |
10 | * |
11 | * This program is free software; you can redistribute it and/or modify | |
12 | * it under the terms of the GNU General Public License version 2 as | |
13 | * publishhed by the Free Software Foundation. | |
14 | */ | |
15 | ||
16 | #include <linux/module.h> | |
17 | #include <linux/kernel.h> | |
18 | #include <linux/init.h> | |
19 | #include <linux/err.h> | |
20 | #include <linux/hwmon.h> | |
21 | #include <linux/hwmon-sysfs.h> | |
22 | #include <linux/spi/spi.h> | |
5a0e3ad6 | 23 | #include <linux/slab.h> |
55b951e7 | 24 | |
9224c38a GR |
25 | enum chips { max1110, max1111, max1112, max1113 }; |
26 | ||
55b951e7 EM |
27 | #define MAX1111_TX_BUF_SIZE 1 |
28 | #define MAX1111_RX_BUF_SIZE 2 | |
29 | ||
30 | /* MAX1111 Commands */ | |
31 | #define MAX1111_CTRL_PD0 (1u << 0) | |
32 | #define MAX1111_CTRL_PD1 (1u << 1) | |
33 | #define MAX1111_CTRL_SGL (1u << 2) | |
34 | #define MAX1111_CTRL_UNI (1u << 3) | |
9224c38a | 35 | #define MAX1110_CTRL_SEL_SH (4) |
55b951e7 EM |
36 | #define MAX1111_CTRL_SEL_SH (5) /* NOTE: bit 4 is ignored */ |
37 | #define MAX1111_CTRL_STR (1u << 7) | |
38 | ||
39 | struct max1111_data { | |
40 | struct spi_device *spi; | |
41 | struct device *hwmon_dev; | |
42 | struct spi_message msg; | |
43 | struct spi_transfer xfer[2]; | |
d737c09c JD |
44 | uint8_t tx_buf[MAX1111_TX_BUF_SIZE]; |
45 | uint8_t rx_buf[MAX1111_RX_BUF_SIZE]; | |
d3f684f2 PH |
46 | struct mutex drvdata_lock; |
47 | /* protect msg, xfer and buffers from multiple access */ | |
9224c38a GR |
48 | int sel_sh; |
49 | int lsb; | |
55b951e7 EM |
50 | }; |
51 | ||
52 | static int max1111_read(struct device *dev, int channel) | |
53 | { | |
54 | struct max1111_data *data = dev_get_drvdata(dev); | |
55 | uint8_t v1, v2; | |
56 | int err; | |
57 | ||
d3f684f2 PH |
58 | /* writing to drvdata struct is not thread safe, wait on mutex */ |
59 | mutex_lock(&data->drvdata_lock); | |
60 | ||
9224c38a | 61 | data->tx_buf[0] = (channel << data->sel_sh) | |
55b951e7 EM |
62 | MAX1111_CTRL_PD0 | MAX1111_CTRL_PD1 | |
63 | MAX1111_CTRL_SGL | MAX1111_CTRL_UNI | MAX1111_CTRL_STR; | |
64 | ||
65 | err = spi_sync(data->spi, &data->msg); | |
66 | if (err < 0) { | |
67 | dev_err(dev, "spi_sync failed with %d\n", err); | |
d3f684f2 | 68 | mutex_unlock(&data->drvdata_lock); |
55b951e7 EM |
69 | return err; |
70 | } | |
71 | ||
72 | v1 = data->rx_buf[0]; | |
73 | v2 = data->rx_buf[1]; | |
74 | ||
d3f684f2 PH |
75 | mutex_unlock(&data->drvdata_lock); |
76 | ||
55b951e7 EM |
77 | if ((v1 & 0xc0) || (v2 & 0x3f)) |
78 | return -EINVAL; | |
79 | ||
80 | return (v1 << 2) | (v2 >> 6); | |
81 | } | |
82 | ||
f16177c2 EM |
83 | #ifdef CONFIG_SHARPSL_PM |
84 | static struct max1111_data *the_max1111; | |
85 | ||
86 | int max1111_read_channel(int channel) | |
87 | { | |
3c2e2266 GR |
88 | if (!the_max1111 || !the_max1111->spi) |
89 | return -ENODEV; | |
90 | ||
f16177c2 EM |
91 | return max1111_read(&the_max1111->spi->dev, channel); |
92 | } | |
93 | EXPORT_SYMBOL(max1111_read_channel); | |
94 | #endif | |
95 | ||
55b951e7 EM |
96 | /* |
97 | * NOTE: SPI devices do not have a default 'name' attribute, which is | |
98 | * likely to be used by hwmon applications to distinguish between | |
99 | * different devices, explicitly add a name attribute here. | |
100 | */ | |
101 | static ssize_t show_name(struct device *dev, | |
102 | struct device_attribute *attr, char *buf) | |
103 | { | |
9224c38a | 104 | return sprintf(buf, "%s\n", to_spi_device(dev)->modalias); |
55b951e7 EM |
105 | } |
106 | ||
107 | static ssize_t show_adc(struct device *dev, | |
108 | struct device_attribute *attr, char *buf) | |
109 | { | |
9224c38a | 110 | struct max1111_data *data = dev_get_drvdata(dev); |
55b951e7 EM |
111 | int channel = to_sensor_dev_attr(attr)->index; |
112 | int ret; | |
113 | ||
114 | ret = max1111_read(dev, channel); | |
115 | if (ret < 0) | |
116 | return ret; | |
117 | ||
51683ee8 | 118 | /* |
9224c38a GR |
119 | * Assume the reference voltage to be 2.048V or 4.096V, with an 8-bit |
120 | * sample. The LSB weight is 8mV or 16mV depending on the chip type. | |
012f3b91 | 121 | */ |
9224c38a | 122 | return sprintf(buf, "%d\n", ret * data->lsb); |
55b951e7 EM |
123 | } |
124 | ||
125 | #define MAX1111_ADC_ATTR(_id) \ | |
012f3b91 | 126 | SENSOR_DEVICE_ATTR(in##_id##_input, S_IRUGO, show_adc, NULL, _id) |
55b951e7 EM |
127 | |
128 | static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); | |
129 | static MAX1111_ADC_ATTR(0); | |
130 | static MAX1111_ADC_ATTR(1); | |
131 | static MAX1111_ADC_ATTR(2); | |
132 | static MAX1111_ADC_ATTR(3); | |
9224c38a GR |
133 | static MAX1111_ADC_ATTR(4); |
134 | static MAX1111_ADC_ATTR(5); | |
135 | static MAX1111_ADC_ATTR(6); | |
136 | static MAX1111_ADC_ATTR(7); | |
55b951e7 EM |
137 | |
138 | static struct attribute *max1111_attributes[] = { | |
139 | &dev_attr_name.attr, | |
012f3b91 EM |
140 | &sensor_dev_attr_in0_input.dev_attr.attr, |
141 | &sensor_dev_attr_in1_input.dev_attr.attr, | |
142 | &sensor_dev_attr_in2_input.dev_attr.attr, | |
143 | &sensor_dev_attr_in3_input.dev_attr.attr, | |
55b951e7 EM |
144 | NULL, |
145 | }; | |
146 | ||
147 | static const struct attribute_group max1111_attr_group = { | |
148 | .attrs = max1111_attributes, | |
149 | }; | |
150 | ||
9224c38a GR |
151 | static struct attribute *max1110_attributes[] = { |
152 | &sensor_dev_attr_in4_input.dev_attr.attr, | |
153 | &sensor_dev_attr_in5_input.dev_attr.attr, | |
154 | &sensor_dev_attr_in6_input.dev_attr.attr, | |
155 | &sensor_dev_attr_in7_input.dev_attr.attr, | |
156 | NULL, | |
157 | }; | |
158 | ||
159 | static const struct attribute_group max1110_attr_group = { | |
160 | .attrs = max1110_attributes, | |
161 | }; | |
162 | ||
6c931ae1 | 163 | static int setup_transfer(struct max1111_data *data) |
55b951e7 EM |
164 | { |
165 | struct spi_message *m; | |
166 | struct spi_transfer *x; | |
167 | ||
55b951e7 EM |
168 | m = &data->msg; |
169 | x = &data->xfer[0]; | |
170 | ||
171 | spi_message_init(m); | |
172 | ||
173 | x->tx_buf = &data->tx_buf[0]; | |
d737c09c | 174 | x->len = MAX1111_TX_BUF_SIZE; |
55b951e7 EM |
175 | spi_message_add_tail(x, m); |
176 | ||
177 | x++; | |
178 | x->rx_buf = &data->rx_buf[0]; | |
d737c09c | 179 | x->len = MAX1111_RX_BUF_SIZE; |
55b951e7 EM |
180 | spi_message_add_tail(x, m); |
181 | ||
182 | return 0; | |
183 | } | |
184 | ||
6c931ae1 | 185 | static int max1111_probe(struct spi_device *spi) |
55b951e7 | 186 | { |
9224c38a | 187 | enum chips chip = spi_get_device_id(spi)->driver_data; |
55b951e7 EM |
188 | struct max1111_data *data; |
189 | int err; | |
190 | ||
191 | spi->bits_per_word = 8; | |
192 | spi->mode = SPI_MODE_0; | |
193 | err = spi_setup(spi); | |
194 | if (err < 0) | |
195 | return err; | |
196 | ||
661f020f | 197 | data = devm_kzalloc(&spi->dev, sizeof(struct max1111_data), GFP_KERNEL); |
611cd8ae | 198 | if (data == NULL) |
55b951e7 | 199 | return -ENOMEM; |
55b951e7 | 200 | |
9224c38a GR |
201 | switch (chip) { |
202 | case max1110: | |
203 | data->lsb = 8; | |
204 | data->sel_sh = MAX1110_CTRL_SEL_SH; | |
205 | break; | |
206 | case max1111: | |
207 | data->lsb = 8; | |
208 | data->sel_sh = MAX1111_CTRL_SEL_SH; | |
209 | break; | |
210 | case max1112: | |
211 | data->lsb = 16; | |
212 | data->sel_sh = MAX1110_CTRL_SEL_SH; | |
213 | break; | |
214 | case max1113: | |
215 | data->lsb = 16; | |
216 | data->sel_sh = MAX1111_CTRL_SEL_SH; | |
217 | break; | |
218 | } | |
55b951e7 EM |
219 | err = setup_transfer(data); |
220 | if (err) | |
661f020f | 221 | return err; |
55b951e7 | 222 | |
d3f684f2 PH |
223 | mutex_init(&data->drvdata_lock); |
224 | ||
55b951e7 EM |
225 | data->spi = spi; |
226 | spi_set_drvdata(spi, data); | |
227 | ||
228 | err = sysfs_create_group(&spi->dev.kobj, &max1111_attr_group); | |
229 | if (err) { | |
230 | dev_err(&spi->dev, "failed to create attribute group\n"); | |
661f020f | 231 | return err; |
55b951e7 | 232 | } |
9224c38a GR |
233 | if (chip == max1110 || chip == max1112) { |
234 | err = sysfs_create_group(&spi->dev.kobj, &max1110_attr_group); | |
235 | if (err) { | |
236 | dev_err(&spi->dev, | |
237 | "failed to create extended attribute group\n"); | |
238 | goto err_remove; | |
239 | } | |
240 | } | |
55b951e7 EM |
241 | |
242 | data->hwmon_dev = hwmon_device_register(&spi->dev); | |
243 | if (IS_ERR(data->hwmon_dev)) { | |
244 | dev_err(&spi->dev, "failed to create hwmon device\n"); | |
245 | err = PTR_ERR(data->hwmon_dev); | |
246 | goto err_remove; | |
247 | } | |
248 | ||
f16177c2 EM |
249 | #ifdef CONFIG_SHARPSL_PM |
250 | the_max1111 = data; | |
251 | #endif | |
55b951e7 EM |
252 | return 0; |
253 | ||
254 | err_remove: | |
9224c38a | 255 | sysfs_remove_group(&spi->dev.kobj, &max1110_attr_group); |
55b951e7 | 256 | sysfs_remove_group(&spi->dev.kobj, &max1111_attr_group); |
55b951e7 EM |
257 | return err; |
258 | } | |
259 | ||
281dfd0b | 260 | static int max1111_remove(struct spi_device *spi) |
55b951e7 EM |
261 | { |
262 | struct max1111_data *data = spi_get_drvdata(spi); | |
263 | ||
3c2e2266 GR |
264 | #ifdef CONFIG_SHARPSL_PM |
265 | the_max1111 = NULL; | |
266 | #endif | |
55b951e7 | 267 | hwmon_device_unregister(data->hwmon_dev); |
9224c38a | 268 | sysfs_remove_group(&spi->dev.kobj, &max1110_attr_group); |
55b951e7 | 269 | sysfs_remove_group(&spi->dev.kobj, &max1111_attr_group); |
d3f684f2 | 270 | mutex_destroy(&data->drvdata_lock); |
55b951e7 EM |
271 | return 0; |
272 | } | |
273 | ||
9224c38a GR |
274 | static const struct spi_device_id max1111_ids[] = { |
275 | { "max1110", max1110 }, | |
276 | { "max1111", max1111 }, | |
277 | { "max1112", max1112 }, | |
278 | { "max1113", max1113 }, | |
279 | { }, | |
280 | }; | |
281 | MODULE_DEVICE_TABLE(spi, max1111_ids); | |
282 | ||
55b951e7 EM |
283 | static struct spi_driver max1111_driver = { |
284 | .driver = { | |
285 | .name = "max1111", | |
55b951e7 | 286 | }, |
9224c38a | 287 | .id_table = max1111_ids, |
55b951e7 | 288 | .probe = max1111_probe, |
9e5e9b7a | 289 | .remove = max1111_remove, |
55b951e7 EM |
290 | }; |
291 | ||
91efffe2 | 292 | module_spi_driver(max1111_driver); |
55b951e7 EM |
293 | |
294 | MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>"); | |
9224c38a | 295 | MODULE_DESCRIPTION("MAX1110/MAX1111/MAX1112/MAX1113 ADC Driver"); |
55b951e7 | 296 | MODULE_LICENSE("GPL"); |