Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 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 | |
Joe Perches | 5713017 | 2010-10-20 06:51:41 +0000 | [diff] [blame] | 27 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 28 | |
Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 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> |
Matthias Kaehlcke | 4bfe660 | 2007-10-24 14:59:09 +0200 | [diff] [blame] | 36 | #include <linux/mutex.h> |
Anton Vorontsov | 8cec03e | 2009-09-22 16:46:07 -0700 | [diff] [blame] | 37 | #include <linux/mod_devicetable.h> |
Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 38 | #include <linux/spi/spi.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 39 | #include <linux/slab.h> |
Matthias Kaehlcke | 4bfe660 | 2007-10-24 14:59:09 +0200 | [diff] [blame] | 40 | |
Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 41 | |
| 42 | #define DRVNAME "lm70" |
| 43 | |
Manuel Lauss | c8ac32e | 2009-01-07 16:37:34 +0100 | [diff] [blame] | 44 | #define LM70_CHIP_LM70 0 /* original NS LM70 */ |
| 45 | #define LM70_CHIP_TMP121 1 /* TI TMP121/TMP123 */ |
| 46 | |
Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 47 | struct lm70 { |
Tony Jones | 1beeffe | 2007-08-20 13:46:20 -0700 | [diff] [blame] | 48 | struct device *hwmon_dev; |
Matthias Kaehlcke | 4bfe660 | 2007-10-24 14:59:09 +0200 | [diff] [blame] | 49 | struct mutex lock; |
Manuel Lauss | c8ac32e | 2009-01-07 16:37:34 +0100 | [diff] [blame] | 50 | unsigned int chip; |
Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 51 | }; |
| 52 | |
| 53 | /* sysfs hook function */ |
| 54 | static ssize_t lm70_sense_temp(struct device *dev, |
| 55 | struct device_attribute *attr, char *buf) |
| 56 | { |
| 57 | struct spi_device *spi = to_spi_device(dev); |
Manuel Lauss | c8ac32e | 2009-01-07 16:37:34 +0100 | [diff] [blame] | 58 | int status, val = 0; |
Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 59 | u8 rxbuf[2]; |
Frans Meulenbroeks | 56c24af | 2012-01-08 19:34:11 +0100 | [diff] [blame] | 60 | s16 raw = 0; |
Jean Delvare | 95de3b2 | 2011-05-25 20:43:31 +0200 | [diff] [blame] | 61 | struct lm70 *p_lm70 = spi_get_drvdata(spi); |
Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 62 | |
Matthias Kaehlcke | 4bfe660 | 2007-10-24 14:59:09 +0200 | [diff] [blame] | 63 | if (mutex_lock_interruptible(&p_lm70->lock)) |
Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 64 | return -ERESTARTSYS; |
| 65 | |
| 66 | /* |
| 67 | * spi_read() requires a DMA-safe buffer; so we use |
| 68 | * spi_write_then_read(), transmitting 0 bytes. |
| 69 | */ |
| 70 | status = spi_write_then_read(spi, NULL, 0, &rxbuf[0], 2); |
| 71 | if (status < 0) { |
Joe Perches | 5713017 | 2010-10-20 06:51:41 +0000 | [diff] [blame] | 72 | pr_warn("spi_write_then_read failed with status %d\n", status); |
Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 73 | goto out; |
| 74 | } |
Kaiwan N Billimoria | 2b73005 | 2009-01-07 16:37:34 +0100 | [diff] [blame] | 75 | raw = (rxbuf[0] << 8) + rxbuf[1]; |
| 76 | dev_dbg(dev, "rxbuf[0] : 0x%02x rxbuf[1] : 0x%02x raw=0x%04x\n", |
| 77 | rxbuf[0], rxbuf[1], raw); |
Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 78 | |
| 79 | /* |
Manuel Lauss | c8ac32e | 2009-01-07 16:37:34 +0100 | [diff] [blame] | 80 | * LM70: |
Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 81 | * The "raw" temperature read into rxbuf[] is a 16-bit signed 2's |
| 82 | * complement value. Only the MSB 11 bits (1 sign + 10 temperature |
| 83 | * bits) are meaningful; the LSB 5 bits are to be discarded. |
| 84 | * See the datasheet. |
| 85 | * |
| 86 | * Further, each bit represents 0.25 degrees Celsius; so, multiply |
| 87 | * by 0.25. Also multiply by 1000 to represent in millidegrees |
| 88 | * Celsius. |
| 89 | * So it's equivalent to multiplying by 0.25 * 1000 = 250. |
Manuel Lauss | c8ac32e | 2009-01-07 16:37:34 +0100 | [diff] [blame] | 90 | * |
| 91 | * TMP121/TMP123: |
| 92 | * 13 bits of 2's complement data, discard LSB 3 bits, |
| 93 | * resolution 0.0625 degrees celsius. |
Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 94 | */ |
Manuel Lauss | c8ac32e | 2009-01-07 16:37:34 +0100 | [diff] [blame] | 95 | switch (p_lm70->chip) { |
| 96 | case LM70_CHIP_LM70: |
| 97 | val = ((int)raw / 32) * 250; |
| 98 | break; |
| 99 | |
| 100 | case LM70_CHIP_TMP121: |
| 101 | val = ((int)raw / 8) * 625 / 10; |
| 102 | break; |
| 103 | } |
| 104 | |
Jean Delvare | 67f921d | 2007-08-17 17:31:35 +0200 | [diff] [blame] | 105 | status = sprintf(buf, "%d\n", val); /* millidegrees Celsius */ |
Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 106 | out: |
Matthias Kaehlcke | 4bfe660 | 2007-10-24 14:59:09 +0200 | [diff] [blame] | 107 | mutex_unlock(&p_lm70->lock); |
Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 108 | return status; |
| 109 | } |
| 110 | |
| 111 | static DEVICE_ATTR(temp1_input, S_IRUGO, lm70_sense_temp, NULL); |
| 112 | |
Jean Delvare | 67f921d | 2007-08-17 17:31:35 +0200 | [diff] [blame] | 113 | static ssize_t lm70_show_name(struct device *dev, struct device_attribute |
| 114 | *devattr, char *buf) |
| 115 | { |
Manuel Lauss | c8ac32e | 2009-01-07 16:37:34 +0100 | [diff] [blame] | 116 | struct lm70 *p_lm70 = dev_get_drvdata(dev); |
| 117 | int ret; |
| 118 | |
| 119 | switch (p_lm70->chip) { |
| 120 | case LM70_CHIP_LM70: |
| 121 | ret = sprintf(buf, "lm70\n"); |
| 122 | break; |
| 123 | case LM70_CHIP_TMP121: |
| 124 | ret = sprintf(buf, "tmp121\n"); |
| 125 | break; |
| 126 | default: |
| 127 | ret = -EINVAL; |
| 128 | } |
| 129 | return ret; |
Jean Delvare | 67f921d | 2007-08-17 17:31:35 +0200 | [diff] [blame] | 130 | } |
| 131 | |
| 132 | static DEVICE_ATTR(name, S_IRUGO, lm70_show_name, NULL); |
| 133 | |
Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 134 | /*----------------------------------------------------------------------*/ |
| 135 | |
Anton Vorontsov | 8cec03e | 2009-09-22 16:46:07 -0700 | [diff] [blame] | 136 | static int __devinit lm70_probe(struct spi_device *spi) |
Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 137 | { |
Anton Vorontsov | 8cec03e | 2009-09-22 16:46:07 -0700 | [diff] [blame] | 138 | int chip = spi_get_device_id(spi)->driver_data; |
Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 139 | struct lm70 *p_lm70; |
| 140 | int status; |
| 141 | |
Anton Vorontsov | 8cec03e | 2009-09-22 16:46:07 -0700 | [diff] [blame] | 142 | /* signaling is SPI_MODE_0 for both LM70 and TMP121 */ |
| 143 | if (spi->mode & (SPI_CPOL | SPI_CPHA)) |
| 144 | return -EINVAL; |
| 145 | |
| 146 | /* 3-wire link (shared SI/SO) for LM70 */ |
| 147 | if (chip == LM70_CHIP_LM70 && !(spi->mode & SPI_3WIRE)) |
| 148 | return -EINVAL; |
| 149 | |
Kaiwan N Billimoria | 2b73005 | 2009-01-07 16:37:34 +0100 | [diff] [blame] | 150 | /* NOTE: we assume 8-bit words, and convert to 16 bits manually */ |
| 151 | |
Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 152 | p_lm70 = kzalloc(sizeof *p_lm70, GFP_KERNEL); |
| 153 | if (!p_lm70) |
| 154 | return -ENOMEM; |
| 155 | |
Matthias Kaehlcke | 4bfe660 | 2007-10-24 14:59:09 +0200 | [diff] [blame] | 156 | mutex_init(&p_lm70->lock); |
Manuel Lauss | c8ac32e | 2009-01-07 16:37:34 +0100 | [diff] [blame] | 157 | p_lm70->chip = chip; |
Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 158 | |
Jean Delvare | 95de3b2 | 2011-05-25 20:43:31 +0200 | [diff] [blame] | 159 | spi_set_drvdata(spi, p_lm70); |
Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 160 | |
Guenter Roeck | 7599d32 | 2012-01-19 21:05:07 -0800 | [diff] [blame^] | 161 | status = device_create_file(&spi->dev, &dev_attr_temp1_input); |
| 162 | if (status) |
| 163 | goto out_dev_create_temp_file_failed; |
| 164 | status = device_create_file(&spi->dev, &dev_attr_name); |
| 165 | if (status) |
Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 166 | goto out_dev_create_file_failed; |
Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 167 | |
Guenter Roeck | e200c14 | 2012-01-19 20:58:13 -0800 | [diff] [blame] | 168 | /* sysfs hook */ |
| 169 | p_lm70->hwmon_dev = hwmon_device_register(&spi->dev); |
| 170 | if (IS_ERR(p_lm70->hwmon_dev)) { |
| 171 | dev_dbg(&spi->dev, "hwmon_device_register failed.\n"); |
| 172 | status = PTR_ERR(p_lm70->hwmon_dev); |
| 173 | goto out_dev_reg_failed; |
| 174 | } |
| 175 | |
Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 176 | return 0; |
| 177 | |
Guenter Roeck | e200c14 | 2012-01-19 20:58:13 -0800 | [diff] [blame] | 178 | out_dev_reg_failed: |
| 179 | device_remove_file(&spi->dev, &dev_attr_name); |
Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 180 | out_dev_create_file_failed: |
Jean Delvare | 67f921d | 2007-08-17 17:31:35 +0200 | [diff] [blame] | 181 | device_remove_file(&spi->dev, &dev_attr_temp1_input); |
Guenter Roeck | 7599d32 | 2012-01-19 21:05:07 -0800 | [diff] [blame^] | 182 | out_dev_create_temp_file_failed: |
Jean Delvare | 95de3b2 | 2011-05-25 20:43:31 +0200 | [diff] [blame] | 183 | spi_set_drvdata(spi, NULL); |
Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 184 | kfree(p_lm70); |
| 185 | return status; |
| 186 | } |
| 187 | |
Ralf Baechle | 41be722 | 2007-02-14 21:15:04 +0100 | [diff] [blame] | 188 | static int __devexit lm70_remove(struct spi_device *spi) |
Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 189 | { |
Jean Delvare | 95de3b2 | 2011-05-25 20:43:31 +0200 | [diff] [blame] | 190 | struct lm70 *p_lm70 = spi_get_drvdata(spi); |
Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 191 | |
Guenter Roeck | e200c14 | 2012-01-19 20:58:13 -0800 | [diff] [blame] | 192 | hwmon_device_unregister(p_lm70->hwmon_dev); |
Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 193 | device_remove_file(&spi->dev, &dev_attr_temp1_input); |
Jean Delvare | 67f921d | 2007-08-17 17:31:35 +0200 | [diff] [blame] | 194 | device_remove_file(&spi->dev, &dev_attr_name); |
Jean Delvare | 95de3b2 | 2011-05-25 20:43:31 +0200 | [diff] [blame] | 195 | spi_set_drvdata(spi, NULL); |
Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 196 | kfree(p_lm70); |
| 197 | |
| 198 | return 0; |
| 199 | } |
| 200 | |
Anton Vorontsov | 8cec03e | 2009-09-22 16:46:07 -0700 | [diff] [blame] | 201 | |
| 202 | static const struct spi_device_id lm70_ids[] = { |
| 203 | { "lm70", LM70_CHIP_LM70 }, |
| 204 | { "tmp121", LM70_CHIP_TMP121 }, |
| 205 | { }, |
Manuel Lauss | c8ac32e | 2009-01-07 16:37:34 +0100 | [diff] [blame] | 206 | }; |
Anton Vorontsov | 8cec03e | 2009-09-22 16:46:07 -0700 | [diff] [blame] | 207 | MODULE_DEVICE_TABLE(spi, lm70_ids); |
Manuel Lauss | c8ac32e | 2009-01-07 16:37:34 +0100 | [diff] [blame] | 208 | |
Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 209 | static struct spi_driver lm70_driver = { |
| 210 | .driver = { |
| 211 | .name = "lm70", |
| 212 | .owner = THIS_MODULE, |
| 213 | }, |
Anton Vorontsov | 8cec03e | 2009-09-22 16:46:07 -0700 | [diff] [blame] | 214 | .id_table = lm70_ids, |
Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 215 | .probe = lm70_probe, |
| 216 | .remove = __devexit_p(lm70_remove), |
| 217 | }; |
| 218 | |
Axel Lin | 91efffe | 2012-01-20 15:53:47 +0800 | [diff] [blame] | 219 | module_spi_driver(lm70_driver); |
Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 220 | |
| 221 | MODULE_AUTHOR("Kaiwan N Billimoria"); |
Manuel Lauss | c8ac32e | 2009-01-07 16:37:34 +0100 | [diff] [blame] | 222 | MODULE_DESCRIPTION("NS LM70 / TI TMP121/TMP123 Linux driver"); |
Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 223 | MODULE_LICENSE("GPL"); |