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74ba9207 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
e1a8e913 KB |
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 | |
e1a8e913 KB |
12 | */ |
13 | ||
5713017e JP |
14 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
15 | ||
e1a8e913 KB |
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> | |
4bfe6604 | 23 | #include <linux/mutex.h> |
8cec03ee | 24 | #include <linux/mod_devicetable.h> |
ac61c8aa | 25 | #include <linux/of.h> |
6e09d755 | 26 | #include <linux/property.h> |
e1a8e913 | 27 | #include <linux/spi/spi.h> |
5a0e3ad6 | 28 | #include <linux/slab.h> |
e1a8e913 KB |
29 | |
30 | #define DRVNAME "lm70" | |
31 | ||
c8ac32e4 ML |
32 | #define LM70_CHIP_LM70 0 /* original NS LM70 */ |
33 | #define LM70_CHIP_TMP121 1 /* TI TMP121/TMP123 */ | |
a86e94dc CL |
34 | #define LM70_CHIP_LM71 2 /* NS LM71 */ |
35 | #define LM70_CHIP_LM74 3 /* NS LM74 */ | |
68f0c8c9 | 36 | #define LM70_CHIP_TMP122 4 /* TI TMP122/TMP124 */ |
cd929672 | 37 | #define LM70_CHIP_TMP125 5 /* TI TMP125 */ |
c8ac32e4 | 38 | |
e1a8e913 | 39 | struct lm70 { |
aa9bcdda | 40 | struct spi_device *spi; |
4bfe6604 | 41 | struct mutex lock; |
c8ac32e4 | 42 | unsigned int chip; |
e1a8e913 KB |
43 | }; |
44 | ||
45 | /* sysfs hook function */ | |
89cb4af8 JL |
46 | static ssize_t temp1_input_show(struct device *dev, |
47 | struct device_attribute *attr, char *buf) | |
e1a8e913 | 48 | { |
aa9bcdda GR |
49 | struct lm70 *p_lm70 = dev_get_drvdata(dev); |
50 | struct spi_device *spi = p_lm70->spi; | |
c8ac32e4 | 51 | int status, val = 0; |
e1a8e913 | 52 | u8 rxbuf[2]; |
56c24af8 | 53 | s16 raw = 0; |
e1a8e913 | 54 | |
4bfe6604 | 55 | if (mutex_lock_interruptible(&p_lm70->lock)) |
e1a8e913 KB |
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) { | |
e8295146 FF |
64 | dev_warn(dev, "spi_write_then_read failed with status %d\n", |
65 | status); | |
e1a8e913 KB |
66 | goto out; |
67 | } | |
2b730051 KB |
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); | |
e1a8e913 KB |
71 | |
72 | /* | |
c8ac32e4 | 73 | * LM70: |
e1a8e913 KB |
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. | |
c8ac32e4 | 83 | * |
68f0c8c9 | 84 | * LM74 and TMP121/TMP122/TMP123/TMP124: |
c8ac32e4 ML |
85 | * 13 bits of 2's complement data, discard LSB 3 bits, |
86 | * resolution 0.0625 degrees celsius. | |
a86e94dc CL |
87 | * |
88 | * LM71: | |
89 | * 14 bits of 2's complement data, discard LSB 2 bits, | |
90 | * resolution 0.0312 degrees celsius. | |
cd929672 CL |
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. | |
e1a8e913 | 97 | */ |
c8ac32e4 ML |
98 | switch (p_lm70->chip) { |
99 | case LM70_CHIP_LM70: | |
100 | val = ((int)raw / 32) * 250; | |
101 | break; | |
102 | ||
103 | case LM70_CHIP_TMP121: | |
68f0c8c9 | 104 | case LM70_CHIP_TMP122: |
a86e94dc | 105 | case LM70_CHIP_LM74: |
c8ac32e4 ML |
106 | val = ((int)raw / 8) * 625 / 10; |
107 | break; | |
a86e94dc CL |
108 | |
109 | case LM70_CHIP_LM71: | |
110 | val = ((int)raw / 4) * 3125 / 100; | |
111 | break; | |
cd929672 CL |
112 | |
113 | case LM70_CHIP_TMP125: | |
114 | val = (sign_extend32(raw, 14) / 32) * 250; | |
115 | break; | |
c8ac32e4 ML |
116 | } |
117 | ||
67f921d1 | 118 | status = sprintf(buf, "%d\n", val); /* millidegrees Celsius */ |
e1a8e913 | 119 | out: |
4bfe6604 | 120 | mutex_unlock(&p_lm70->lock); |
e1a8e913 KB |
121 | return status; |
122 | } | |
123 | ||
89cb4af8 | 124 | static DEVICE_ATTR_RO(temp1_input); |
e1a8e913 | 125 | |
aa9bcdda GR |
126 | static struct attribute *lm70_attrs[] = { |
127 | &dev_attr_temp1_input.attr, | |
128 | NULL | |
129 | }; | |
67f921d1 | 130 | |
aa9bcdda | 131 | ATTRIBUTE_GROUPS(lm70); |
67f921d1 | 132 | |
e1a8e913 KB |
133 | /*----------------------------------------------------------------------*/ |
134 | ||
a1dc86eb RV |
135 | #ifdef CONFIG_OF |
136 | static 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 | }, | |
68f0c8c9 FF |
145 | { |
146 | .compatible = "ti,tmp122", | |
147 | .data = (void *) LM70_CHIP_TMP122, | |
148 | }, | |
cd929672 CL |
149 | { |
150 | .compatible = "ti,tmp125", | |
151 | .data = (void *) LM70_CHIP_TMP125, | |
152 | }, | |
a1dc86eb RV |
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 | }; | |
163 | MODULE_DEVICE_TABLE(of, lm70_of_ids); | |
164 | #endif | |
165 | ||
6c931ae1 | 166 | static int lm70_probe(struct spi_device *spi) |
e1a8e913 | 167 | { |
aa9bcdda | 168 | struct device *hwmon_dev; |
e1a8e913 | 169 | struct lm70 *p_lm70; |
a1dc86eb RV |
170 | int chip; |
171 | ||
6e09d755 SB |
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; | |
b58bd4c6 | 176 | |
e1a8e913 | 177 | |
a86e94dc | 178 | /* signaling is SPI_MODE_0 */ |
ba9c5fc3 | 179 | if ((spi->mode & SPI_MODE_X_MASK) != SPI_MODE_0) |
8cec03ee AV |
180 | return -EINVAL; |
181 | ||
2b730051 KB |
182 | /* NOTE: we assume 8-bit words, and convert to 16 bits manually */ |
183 | ||
33ed6d4a | 184 | p_lm70 = devm_kzalloc(&spi->dev, sizeof(*p_lm70), GFP_KERNEL); |
e1a8e913 KB |
185 | if (!p_lm70) |
186 | return -ENOMEM; | |
187 | ||
4bfe6604 | 188 | mutex_init(&p_lm70->lock); |
c8ac32e4 | 189 | p_lm70->chip = chip; |
aa9bcdda | 190 | p_lm70->spi = spi; |
e1a8e913 | 191 | |
aa9bcdda GR |
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); | |
e1a8e913 KB |
196 | } |
197 | ||
8cec03ee AV |
198 | static const struct spi_device_id lm70_ids[] = { |
199 | { "lm70", LM70_CHIP_LM70 }, | |
200 | { "tmp121", LM70_CHIP_TMP121 }, | |
68f0c8c9 | 201 | { "tmp122", LM70_CHIP_TMP122 }, |
cd929672 | 202 | { "tmp125", LM70_CHIP_TMP125 }, |
a86e94dc CL |
203 | { "lm71", LM70_CHIP_LM71 }, |
204 | { "lm74", LM70_CHIP_LM74 }, | |
8cec03ee | 205 | { }, |
c8ac32e4 | 206 | }; |
8cec03ee | 207 | MODULE_DEVICE_TABLE(spi, lm70_ids); |
c8ac32e4 | 208 | |
e1a8e913 KB |
209 | static struct spi_driver lm70_driver = { |
210 | .driver = { | |
211 | .name = "lm70", | |
a1dc86eb | 212 | .of_match_table = of_match_ptr(lm70_of_ids), |
e1a8e913 | 213 | }, |
8cec03ee | 214 | .id_table = lm70_ids, |
e1a8e913 | 215 | .probe = lm70_probe, |
e1a8e913 KB |
216 | }; |
217 | ||
91efffe2 | 218 | module_spi_driver(lm70_driver); |
e1a8e913 KB |
219 | |
220 | MODULE_AUTHOR("Kaiwan N Billimoria"); | |
a86e94dc | 221 | MODULE_DESCRIPTION("NS LM70 and compatibles Linux driver"); |
e1a8e913 | 222 | MODULE_LICENSE("GPL"); |