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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * lm70.c
4 *
5 * The LM70 is a temperature sensor chip from National Semiconductor (NS).
6 * Copyright (C) 2006 Kaiwan N Billimoria <kaiwan@designergraphix.com>
7 *
8 * The LM70 communicates with a host processor via an SPI/Microwire Bus
9 * interface. The complete datasheet is available at National's website
10 * here:
11 * http://www.national.com/pf/LM/LM70.html
12 */
13
14#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15
16#include <linux/init.h>
17#include <linux/module.h>
18#include <linux/kernel.h>
19#include <linux/device.h>
20#include <linux/err.h>
21#include <linux/sysfs.h>
22#include <linux/hwmon.h>
23#include <linux/mutex.h>
24#include <linux/mod_devicetable.h>
25#include <linux/of.h>
26#include <linux/property.h>
27#include <linux/spi/spi.h>
28#include <linux/slab.h>
29
30#define DRVNAME "lm70"
31
32#define LM70_CHIP_LM70 0 /* original NS LM70 */
33#define LM70_CHIP_TMP121 1 /* TI TMP121/TMP123 */
34#define LM70_CHIP_LM71 2 /* NS LM71 */
35#define LM70_CHIP_LM74 3 /* NS LM74 */
36#define LM70_CHIP_TMP122 4 /* TI TMP122/TMP124 */
37#define LM70_CHIP_TMP125 5 /* TI TMP125 */
38
39struct lm70 {
40 struct spi_device *spi;
41 struct mutex lock;
42 unsigned int chip;
43};
44
45/* sysfs hook function */
46static ssize_t temp1_input_show(struct device *dev,
47 struct device_attribute *attr, char *buf)
48{
49 struct lm70 *p_lm70 = dev_get_drvdata(dev);
50 struct spi_device *spi = p_lm70->spi;
51 int status, val = 0;
52 u8 rxbuf[2];
53 s16 raw = 0;
54
55 if (mutex_lock_interruptible(&p_lm70->lock))
56 return -ERESTARTSYS;
57
58 /*
59 * spi_read() requires a DMA-safe buffer; so we use
60 * spi_write_then_read(), transmitting 0 bytes.
61 */
62 status = spi_write_then_read(spi, NULL, 0, &rxbuf[0], 2);
63 if (status < 0) {
64 dev_warn(dev, "spi_write_then_read failed with status %d\n",
65 status);
66 goto out;
67 }
68 raw = (rxbuf[0] << 8) + rxbuf[1];
69 dev_dbg(dev, "rxbuf[0] : 0x%02x rxbuf[1] : 0x%02x raw=0x%04x\n",
70 rxbuf[0], rxbuf[1], raw);
71
72 /*
73 * LM70:
74 * The "raw" temperature read into rxbuf[] is a 16-bit signed 2's
75 * complement value. Only the MSB 11 bits (1 sign + 10 temperature
76 * bits) are meaningful; the LSB 5 bits are to be discarded.
77 * See the datasheet.
78 *
79 * Further, each bit represents 0.25 degrees Celsius; so, multiply
80 * by 0.25. Also multiply by 1000 to represent in millidegrees
81 * Celsius.
82 * So it's equivalent to multiplying by 0.25 * 1000 = 250.
83 *
84 * LM74 and TMP121/TMP122/TMP123/TMP124:
85 * 13 bits of 2's complement data, discard LSB 3 bits,
86 * resolution 0.0625 degrees celsius.
87 *
88 * LM71:
89 * 14 bits of 2's complement data, discard LSB 2 bits,
90 * resolution 0.0312 degrees celsius.
91 *
92 * TMP125:
93 * MSB/D15 is a leading zero. D14 is the sign-bit. This is
94 * followed by 9 temperature bits (D13..D5) in 2's complement
95 * data format with a resolution of 0.25 degrees celsius per unit.
96 * LSB 5 bits (D4..D0) share the same value as D5 and get discarded.
97 */
98 switch (p_lm70->chip) {
99 case LM70_CHIP_LM70:
100 val = ((int)raw / 32) * 250;
101 break;
102
103 case LM70_CHIP_TMP121:
104 case LM70_CHIP_TMP122:
105 case LM70_CHIP_LM74:
106 val = ((int)raw / 8) * 625 / 10;
107 break;
108
109 case LM70_CHIP_LM71:
110 val = ((int)raw / 4) * 3125 / 100;
111 break;
112
113 case LM70_CHIP_TMP125:
114 val = (sign_extend32(raw, 14) / 32) * 250;
115 break;
116 }
117
118 status = sprintf(buf, "%d\n", val); /* millidegrees Celsius */
119out:
120 mutex_unlock(&p_lm70->lock);
121 return status;
122}
123
124static DEVICE_ATTR_RO(temp1_input);
125
126static struct attribute *lm70_attrs[] = {
127 &dev_attr_temp1_input.attr,
128 NULL
129};
130
131ATTRIBUTE_GROUPS(lm70);
132
133/*----------------------------------------------------------------------*/
134
135#ifdef CONFIG_OF
136static const struct of_device_id lm70_of_ids[] = {
137 {
138 .compatible = "ti,lm70",
139 .data = (void *) LM70_CHIP_LM70,
140 },
141 {
142 .compatible = "ti,tmp121",
143 .data = (void *) LM70_CHIP_TMP121,
144 },
145 {
146 .compatible = "ti,tmp122",
147 .data = (void *) LM70_CHIP_TMP122,
148 },
149 {
150 .compatible = "ti,tmp125",
151 .data = (void *) LM70_CHIP_TMP125,
152 },
153 {
154 .compatible = "ti,lm71",
155 .data = (void *) LM70_CHIP_LM71,
156 },
157 {
158 .compatible = "ti,lm74",
159 .data = (void *) LM70_CHIP_LM74,
160 },
161 {},
162};
163MODULE_DEVICE_TABLE(of, lm70_of_ids);
164#endif
165
166static int lm70_probe(struct spi_device *spi)
167{
168 struct device *hwmon_dev;
169 struct lm70 *p_lm70;
170 int chip;
171
172 if (dev_fwnode(&spi->dev))
173 chip = (int)(uintptr_t)device_get_match_data(&spi->dev);
174 else
175 chip = spi_get_device_id(spi)->driver_data;
176
177
178 /* signaling is SPI_MODE_0 */
179 if ((spi->mode & SPI_MODE_X_MASK) != SPI_MODE_0)
180 return -EINVAL;
181
182 /* NOTE: we assume 8-bit words, and convert to 16 bits manually */
183
184 p_lm70 = devm_kzalloc(&spi->dev, sizeof(*p_lm70), GFP_KERNEL);
185 if (!p_lm70)
186 return -ENOMEM;
187
188 mutex_init(&p_lm70->lock);
189 p_lm70->chip = chip;
190 p_lm70->spi = spi;
191
192 hwmon_dev = devm_hwmon_device_register_with_groups(&spi->dev,
193 spi->modalias,
194 p_lm70, lm70_groups);
195 return PTR_ERR_OR_ZERO(hwmon_dev);
196}
197
198static const struct spi_device_id lm70_ids[] = {
199 { "lm70", LM70_CHIP_LM70 },
200 { "tmp121", LM70_CHIP_TMP121 },
201 { "tmp122", LM70_CHIP_TMP122 },
202 { "tmp125", LM70_CHIP_TMP125 },
203 { "lm71", LM70_CHIP_LM71 },
204 { "lm74", LM70_CHIP_LM74 },
205 { },
206};
207MODULE_DEVICE_TABLE(spi, lm70_ids);
208
209static struct spi_driver lm70_driver = {
210 .driver = {
211 .name = "lm70",
212 .of_match_table = of_match_ptr(lm70_of_ids),
213 },
214 .id_table = lm70_ids,
215 .probe = lm70_probe,
216};
217
218module_spi_driver(lm70_driver);
219
220MODULE_AUTHOR("Kaiwan N Billimoria");
221MODULE_DESCRIPTION("NS LM70 and compatibles Linux driver");
222MODULE_LICENSE("GPL");
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * lm70.c
4 *
5 * The LM70 is a temperature sensor chip from National Semiconductor (NS).
6 * Copyright (C) 2006 Kaiwan N Billimoria <kaiwan@designergraphix.com>
7 *
8 * The LM70 communicates with a host processor via an SPI/Microwire Bus
9 * interface. The complete datasheet is available at National's website
10 * here:
11 * http://www.national.com/pf/LM/LM70.html
12 */
13
14#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15
16#include <linux/init.h>
17#include <linux/module.h>
18#include <linux/kernel.h>
19#include <linux/device.h>
20#include <linux/err.h>
21#include <linux/sysfs.h>
22#include <linux/hwmon.h>
23#include <linux/mutex.h>
24#include <linux/mod_devicetable.h>
25#include <linux/spi/spi.h>
26#include <linux/slab.h>
27#include <linux/of_device.h>
28#include <linux/acpi.h>
29
30#define DRVNAME "lm70"
31
32#define LM70_CHIP_LM70 0 /* original NS LM70 */
33#define LM70_CHIP_TMP121 1 /* TI TMP121/TMP123 */
34#define LM70_CHIP_LM71 2 /* NS LM71 */
35#define LM70_CHIP_LM74 3 /* NS LM74 */
36#define LM70_CHIP_TMP122 4 /* TI TMP122/TMP124 */
37
38struct lm70 {
39 struct spi_device *spi;
40 struct mutex lock;
41 unsigned int chip;
42};
43
44/* sysfs hook function */
45static ssize_t temp1_input_show(struct device *dev,
46 struct device_attribute *attr, char *buf)
47{
48 struct lm70 *p_lm70 = dev_get_drvdata(dev);
49 struct spi_device *spi = p_lm70->spi;
50 int status, val = 0;
51 u8 rxbuf[2];
52 s16 raw = 0;
53
54 if (mutex_lock_interruptible(&p_lm70->lock))
55 return -ERESTARTSYS;
56
57 /*
58 * spi_read() requires a DMA-safe buffer; so we use
59 * spi_write_then_read(), transmitting 0 bytes.
60 */
61 status = spi_write_then_read(spi, NULL, 0, &rxbuf[0], 2);
62 if (status < 0) {
63 dev_warn(dev, "spi_write_then_read failed with status %d\n",
64 status);
65 goto out;
66 }
67 raw = (rxbuf[0] << 8) + rxbuf[1];
68 dev_dbg(dev, "rxbuf[0] : 0x%02x rxbuf[1] : 0x%02x raw=0x%04x\n",
69 rxbuf[0], rxbuf[1], raw);
70
71 /*
72 * LM70:
73 * The "raw" temperature read into rxbuf[] is a 16-bit signed 2's
74 * complement value. Only the MSB 11 bits (1 sign + 10 temperature
75 * bits) are meaningful; the LSB 5 bits are to be discarded.
76 * See the datasheet.
77 *
78 * Further, each bit represents 0.25 degrees Celsius; so, multiply
79 * by 0.25. Also multiply by 1000 to represent in millidegrees
80 * Celsius.
81 * So it's equivalent to multiplying by 0.25 * 1000 = 250.
82 *
83 * LM74 and TMP121/TMP122/TMP123/TMP124:
84 * 13 bits of 2's complement data, discard LSB 3 bits,
85 * resolution 0.0625 degrees celsius.
86 *
87 * LM71:
88 * 14 bits of 2's complement data, discard LSB 2 bits,
89 * resolution 0.0312 degrees celsius.
90 */
91 switch (p_lm70->chip) {
92 case LM70_CHIP_LM70:
93 val = ((int)raw / 32) * 250;
94 break;
95
96 case LM70_CHIP_TMP121:
97 case LM70_CHIP_TMP122:
98 case LM70_CHIP_LM74:
99 val = ((int)raw / 8) * 625 / 10;
100 break;
101
102 case LM70_CHIP_LM71:
103 val = ((int)raw / 4) * 3125 / 100;
104 break;
105 }
106
107 status = sprintf(buf, "%d\n", val); /* millidegrees Celsius */
108out:
109 mutex_unlock(&p_lm70->lock);
110 return status;
111}
112
113static DEVICE_ATTR_RO(temp1_input);
114
115static struct attribute *lm70_attrs[] = {
116 &dev_attr_temp1_input.attr,
117 NULL
118};
119
120ATTRIBUTE_GROUPS(lm70);
121
122/*----------------------------------------------------------------------*/
123
124#ifdef CONFIG_OF
125static const struct of_device_id lm70_of_ids[] = {
126 {
127 .compatible = "ti,lm70",
128 .data = (void *) LM70_CHIP_LM70,
129 },
130 {
131 .compatible = "ti,tmp121",
132 .data = (void *) LM70_CHIP_TMP121,
133 },
134 {
135 .compatible = "ti,tmp122",
136 .data = (void *) LM70_CHIP_TMP122,
137 },
138 {
139 .compatible = "ti,lm71",
140 .data = (void *) LM70_CHIP_LM71,
141 },
142 {
143 .compatible = "ti,lm74",
144 .data = (void *) LM70_CHIP_LM74,
145 },
146 {},
147};
148MODULE_DEVICE_TABLE(of, lm70_of_ids);
149#endif
150
151#ifdef CONFIG_ACPI
152static const struct acpi_device_id lm70_acpi_ids[] = {
153 {
154 .id = "LM000070",
155 .driver_data = LM70_CHIP_LM70,
156 },
157 {
158 .id = "TMP00121",
159 .driver_data = LM70_CHIP_TMP121,
160 },
161 {
162 .id = "LM000071",
163 .driver_data = LM70_CHIP_LM71,
164 },
165 {
166 .id = "LM000074",
167 .driver_data = LM70_CHIP_LM74,
168 },
169 {},
170};
171MODULE_DEVICE_TABLE(acpi, lm70_acpi_ids);
172#endif
173
174static int lm70_probe(struct spi_device *spi)
175{
176 const struct of_device_id *of_match;
177 struct device *hwmon_dev;
178 struct lm70 *p_lm70;
179 int chip;
180
181 of_match = of_match_device(lm70_of_ids, &spi->dev);
182 if (of_match)
183 chip = (int)(uintptr_t)of_match->data;
184 else {
185#ifdef CONFIG_ACPI
186 const struct acpi_device_id *acpi_match;
187
188 acpi_match = acpi_match_device(lm70_acpi_ids, &spi->dev);
189 if (acpi_match)
190 chip = (int)(uintptr_t)acpi_match->driver_data;
191 else
192#endif
193 chip = spi_get_device_id(spi)->driver_data;
194 }
195
196 /* signaling is SPI_MODE_0 */
197 if (spi->mode & (SPI_CPOL | SPI_CPHA))
198 return -EINVAL;
199
200 /* NOTE: we assume 8-bit words, and convert to 16 bits manually */
201
202 p_lm70 = devm_kzalloc(&spi->dev, sizeof(*p_lm70), GFP_KERNEL);
203 if (!p_lm70)
204 return -ENOMEM;
205
206 mutex_init(&p_lm70->lock);
207 p_lm70->chip = chip;
208 p_lm70->spi = spi;
209
210 hwmon_dev = devm_hwmon_device_register_with_groups(&spi->dev,
211 spi->modalias,
212 p_lm70, lm70_groups);
213 return PTR_ERR_OR_ZERO(hwmon_dev);
214}
215
216static const struct spi_device_id lm70_ids[] = {
217 { "lm70", LM70_CHIP_LM70 },
218 { "tmp121", LM70_CHIP_TMP121 },
219 { "tmp122", LM70_CHIP_TMP122 },
220 { "lm71", LM70_CHIP_LM71 },
221 { "lm74", LM70_CHIP_LM74 },
222 { },
223};
224MODULE_DEVICE_TABLE(spi, lm70_ids);
225
226static struct spi_driver lm70_driver = {
227 .driver = {
228 .name = "lm70",
229 .of_match_table = of_match_ptr(lm70_of_ids),
230 .acpi_match_table = ACPI_PTR(lm70_acpi_ids),
231 },
232 .id_table = lm70_ids,
233 .probe = lm70_probe,
234};
235
236module_spi_driver(lm70_driver);
237
238MODULE_AUTHOR("Kaiwan N Billimoria");
239MODULE_DESCRIPTION("NS LM70 and compatibles Linux driver");
240MODULE_LICENSE("GPL");