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v6.13.7
  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 TI's website
 10 * here:
 11 * https://www.ti.com/product/LM70
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 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	chip = (kernel_ulong_t)spi_get_device_match_data(spi);
 
 
 
 
173
174	/* signaling is SPI_MODE_0 */
175	if ((spi->mode & SPI_MODE_X_MASK) != SPI_MODE_0)
176		return -EINVAL;
177
178	/* NOTE:  we assume 8-bit words, and convert to 16 bits manually */
179
180	p_lm70 = devm_kzalloc(&spi->dev, sizeof(*p_lm70), GFP_KERNEL);
181	if (!p_lm70)
182		return -ENOMEM;
183
184	mutex_init(&p_lm70->lock);
185	p_lm70->chip = chip;
186	p_lm70->spi = spi;
187
188	hwmon_dev = devm_hwmon_device_register_with_groups(&spi->dev,
189							   spi->modalias,
190							   p_lm70, lm70_groups);
191	return PTR_ERR_OR_ZERO(hwmon_dev);
192}
193
194static const struct spi_device_id lm70_ids[] = {
195	{ "lm70",   LM70_CHIP_LM70 },
196	{ "tmp121", LM70_CHIP_TMP121 },
197	{ "tmp122", LM70_CHIP_TMP122 },
198	{ "tmp125", LM70_CHIP_TMP125 },
199	{ "lm71",   LM70_CHIP_LM71 },
200	{ "lm74",   LM70_CHIP_LM74 },
201	{ },
202};
203MODULE_DEVICE_TABLE(spi, lm70_ids);
204
205static struct spi_driver lm70_driver = {
206	.driver = {
207		.name	= "lm70",
208		.of_match_table	= of_match_ptr(lm70_of_ids),
209	},
210	.id_table = lm70_ids,
211	.probe	= lm70_probe,
212};
213
214module_spi_driver(lm70_driver);
215
216MODULE_AUTHOR("Kaiwan N Billimoria");
217MODULE_DESCRIPTION("NS LM70 and compatibles Linux driver");
218MODULE_LICENSE("GPL");
v4.17
 
  1/*
  2 * lm70.c
  3 *
  4 * The LM70 is a temperature sensor chip from National Semiconductor (NS).
  5 * Copyright (C) 2006 Kaiwan N Billimoria <kaiwan@designergraphix.com>
  6 *
  7 * The LM70 communicates with a host processor via an SPI/Microwire Bus
  8 * interface. The complete datasheet is available at National's website
  9 * here:
 10 * http://www.national.com/pf/LM/LM70.html
 11 *
 12 * This program is free software; you can redistribute it and/or modify
 13 * it under the terms of the GNU General Public License as published by
 14 * the Free Software Foundation; either version 2 of the License, or
 15 * (at your option) any later version.
 16 *
 17 * This program is distributed in the hope that it will be useful,
 18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 20 * GNU General Public License for more details.
 21 *
 22 * You should have received a copy of the GNU General Public License
 23 * along with this program; if not, write to the Free Software
 24 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 25 */
 26
 27#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 28
 29#include <linux/init.h>
 30#include <linux/module.h>
 31#include <linux/kernel.h>
 32#include <linux/device.h>
 33#include <linux/err.h>
 34#include <linux/sysfs.h>
 35#include <linux/hwmon.h>
 36#include <linux/mutex.h>
 37#include <linux/mod_devicetable.h>
 
 
 38#include <linux/spi/spi.h>
 39#include <linux/slab.h>
 40#include <linux/of_device.h>
 41
 42
 43#define DRVNAME		"lm70"
 44
 45#define LM70_CHIP_LM70		0	/* original NS LM70 */
 46#define LM70_CHIP_TMP121	1	/* TI TMP121/TMP123 */
 47#define LM70_CHIP_LM71		2	/* NS LM71 */
 48#define LM70_CHIP_LM74		3	/* NS LM74 */
 49#define LM70_CHIP_TMP122	4	/* TI TMP122/TMP124 */
 
 50
 51struct lm70 {
 52	struct spi_device *spi;
 53	struct mutex lock;
 54	unsigned int chip;
 55};
 56
 57/* sysfs hook function */
 58static ssize_t temp1_input_show(struct device *dev,
 59				struct device_attribute *attr, char *buf)
 60{
 61	struct lm70 *p_lm70 = dev_get_drvdata(dev);
 62	struct spi_device *spi = p_lm70->spi;
 63	int status, val = 0;
 64	u8 rxbuf[2];
 65	s16 raw = 0;
 66
 67	if (mutex_lock_interruptible(&p_lm70->lock))
 68		return -ERESTARTSYS;
 69
 70	/*
 71	 * spi_read() requires a DMA-safe buffer; so we use
 72	 * spi_write_then_read(), transmitting 0 bytes.
 73	 */
 74	status = spi_write_then_read(spi, NULL, 0, &rxbuf[0], 2);
 75	if (status < 0) {
 76		dev_warn(dev, "spi_write_then_read failed with status %d\n",
 77			 status);
 78		goto out;
 79	}
 80	raw = (rxbuf[0] << 8) + rxbuf[1];
 81	dev_dbg(dev, "rxbuf[0] : 0x%02x rxbuf[1] : 0x%02x raw=0x%04x\n",
 82		rxbuf[0], rxbuf[1], raw);
 83
 84	/*
 85	 * LM70:
 86	 * The "raw" temperature read into rxbuf[] is a 16-bit signed 2's
 87	 * complement value. Only the MSB 11 bits (1 sign + 10 temperature
 88	 * bits) are meaningful; the LSB 5 bits are to be discarded.
 89	 * See the datasheet.
 90	 *
 91	 * Further, each bit represents 0.25 degrees Celsius; so, multiply
 92	 * by 0.25. Also multiply by 1000 to represent in millidegrees
 93	 * Celsius.
 94	 * So it's equivalent to multiplying by 0.25 * 1000 = 250.
 95	 *
 96	 * LM74 and TMP121/TMP122/TMP123/TMP124:
 97	 * 13 bits of 2's complement data, discard LSB 3 bits,
 98	 * resolution 0.0625 degrees celsius.
 99	 *
100	 * LM71:
101	 * 14 bits of 2's complement data, discard LSB 2 bits,
102	 * resolution 0.0312 degrees celsius.
 
 
 
 
 
 
103	 */
104	switch (p_lm70->chip) {
105	case LM70_CHIP_LM70:
106		val = ((int)raw / 32) * 250;
107		break;
108
109	case LM70_CHIP_TMP121:
110	case LM70_CHIP_TMP122:
111	case LM70_CHIP_LM74:
112		val = ((int)raw / 8) * 625 / 10;
113		break;
114
115	case LM70_CHIP_LM71:
116		val = ((int)raw / 4) * 3125 / 100;
117		break;
 
 
 
 
118	}
119
120	status = sprintf(buf, "%d\n", val); /* millidegrees Celsius */
121out:
122	mutex_unlock(&p_lm70->lock);
123	return status;
124}
125
126static DEVICE_ATTR_RO(temp1_input);
127
128static struct attribute *lm70_attrs[] = {
129	&dev_attr_temp1_input.attr,
130	NULL
131};
132
133ATTRIBUTE_GROUPS(lm70);
134
135/*----------------------------------------------------------------------*/
136
137#ifdef CONFIG_OF
138static const struct of_device_id lm70_of_ids[] = {
139	{
140		.compatible = "ti,lm70",
141		.data = (void *) LM70_CHIP_LM70,
142	},
143	{
144		.compatible = "ti,tmp121",
145		.data = (void *) LM70_CHIP_TMP121,
146	},
147	{
148		.compatible = "ti,tmp122",
149		.data = (void *) LM70_CHIP_TMP122,
150	},
151	{
 
 
 
 
152		.compatible = "ti,lm71",
153		.data = (void *) LM70_CHIP_LM71,
154	},
155	{
156		.compatible = "ti,lm74",
157		.data = (void *) LM70_CHIP_LM74,
158	},
159	{},
160};
161MODULE_DEVICE_TABLE(of, lm70_of_ids);
162#endif
163
164static int lm70_probe(struct spi_device *spi)
165{
166	const struct of_device_id *match;
167	struct device *hwmon_dev;
168	struct lm70 *p_lm70;
169	int chip;
170
171	match = of_match_device(lm70_of_ids, &spi->dev);
172	if (match)
173		chip = (int)(uintptr_t)match->data;
174	else
175		chip = spi_get_device_id(spi)->driver_data;
176
177	/* signaling is SPI_MODE_0 */
178	if (spi->mode & (SPI_CPOL | SPI_CPHA))
179		return -EINVAL;
180
181	/* NOTE:  we assume 8-bit words, and convert to 16 bits manually */
182
183	p_lm70 = devm_kzalloc(&spi->dev, sizeof(*p_lm70), GFP_KERNEL);
184	if (!p_lm70)
185		return -ENOMEM;
186
187	mutex_init(&p_lm70->lock);
188	p_lm70->chip = chip;
189	p_lm70->spi = spi;
190
191	hwmon_dev = devm_hwmon_device_register_with_groups(&spi->dev,
192							   spi->modalias,
193							   p_lm70, lm70_groups);
194	return PTR_ERR_OR_ZERO(hwmon_dev);
195}
196
197static const struct spi_device_id lm70_ids[] = {
198	{ "lm70",   LM70_CHIP_LM70 },
199	{ "tmp121", LM70_CHIP_TMP121 },
200	{ "tmp122", LM70_CHIP_TMP122 },
 
201	{ "lm71",   LM70_CHIP_LM71 },
202	{ "lm74",   LM70_CHIP_LM74 },
203	{ },
204};
205MODULE_DEVICE_TABLE(spi, lm70_ids);
206
207static struct spi_driver lm70_driver = {
208	.driver = {
209		.name	= "lm70",
210		.of_match_table	= of_match_ptr(lm70_of_ids),
211	},
212	.id_table = lm70_ids,
213	.probe	= lm70_probe,
214};
215
216module_spi_driver(lm70_driver);
217
218MODULE_AUTHOR("Kaiwan N Billimoria");
219MODULE_DESCRIPTION("NS LM70 and compatibles Linux driver");
220MODULE_LICENSE("GPL");