Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 | /*
* adcxx.c
*
* The adcxx4s is an AD converter family from National Semiconductor (NS).
*
* Copyright (c) 2008 Marc Pignat <marc.pignat@hevs.ch>
*
* The adcxx4s communicates with a host processor via an SPI/Microwire Bus
* interface. This driver supports the whole family of devices with name
* ADC<bb><c>S<sss>, where
* * bb is the resolution in number of bits (8, 10, 12)
* * c is the number of channels (1, 2, 4, 8)
* * sss is the maximum conversion speed (021 for 200 kSPS, 051 for 500 kSPS
* and 101 for 1 MSPS)
*
* Complete datasheets are available at National's website here:
* http://www.national.com/ds/DC/ADC<bb><c>S<sss>.pdf
*
* Handling of 8, 10 and 12 bits converters are the same, the
* unavailable bits are 0 :)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/sysfs.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/mutex.h>
#include <linux/mod_devicetable.h>
#include <linux/spi/spi.h>
#define DRVNAME "adcxx"
struct adcxx {
struct device *hwmon_dev;
struct mutex lock;
u32 channels;
u32 reference; /* in millivolts */
};
/* sysfs hook function */
static ssize_t adcxx_read(struct device *dev,
struct device_attribute *devattr, char *buf)
{
struct spi_device *spi = to_spi_device(dev);
struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
struct adcxx *adc = dev_get_drvdata(&spi->dev);
u8 tx_buf[2];
u8 rx_buf[2];
int status;
u32 value;
if (mutex_lock_interruptible(&adc->lock))
return -ERESTARTSYS;
if (adc->channels == 1) {
status = spi_read(spi, rx_buf, sizeof(rx_buf));
} else {
tx_buf[0] = attr->index << 3; /* other bits are don't care */
status = spi_write_then_read(spi, tx_buf, sizeof(tx_buf),
rx_buf, sizeof(rx_buf));
}
if (status < 0) {
dev_warn(dev, "SPI synch. transfer failed with status %d\n",
status);
goto out;
}
value = (rx_buf[0] << 8) + rx_buf[1];
dev_dbg(dev, "raw value = 0x%x\n", value);
value = value * adc->reference >> 12;
status = sprintf(buf, "%d\n", value);
out:
mutex_unlock(&adc->lock);
return status;
}
static ssize_t adcxx_show_min(struct device *dev,
struct device_attribute *devattr, char *buf)
{
/* The minimum reference is 0 for this chip family */
return sprintf(buf, "0\n");
}
static ssize_t adcxx_show_max(struct device *dev,
struct device_attribute *devattr, char *buf)
{
struct spi_device *spi = to_spi_device(dev);
struct adcxx *adc = dev_get_drvdata(&spi->dev);
u32 reference;
if (mutex_lock_interruptible(&adc->lock))
return -ERESTARTSYS;
reference = adc->reference;
mutex_unlock(&adc->lock);
return sprintf(buf, "%d\n", reference);
}
static ssize_t adcxx_set_max(struct device *dev,
struct device_attribute *devattr, const char *buf, size_t count)
{
struct spi_device *spi = to_spi_device(dev);
struct adcxx *adc = dev_get_drvdata(&spi->dev);
unsigned long value;
if (strict_strtoul(buf, 10, &value))
return -EINVAL;
if (mutex_lock_interruptible(&adc->lock))
return -ERESTARTSYS;
adc->reference = value;
mutex_unlock(&adc->lock);
return count;
}
static ssize_t adcxx_show_name(struct device *dev, struct device_attribute
*devattr, char *buf)
{
struct spi_device *spi = to_spi_device(dev);
struct adcxx *adc = dev_get_drvdata(&spi->dev);
return sprintf(buf, "adcxx%ds\n", adc->channels);
}
static struct sensor_device_attribute ad_input[] = {
SENSOR_ATTR(name, S_IRUGO, adcxx_show_name, NULL, 0),
SENSOR_ATTR(in_min, S_IRUGO, adcxx_show_min, NULL, 0),
SENSOR_ATTR(in_max, S_IWUSR | S_IRUGO, adcxx_show_max,
adcxx_set_max, 0),
SENSOR_ATTR(in0_input, S_IRUGO, adcxx_read, NULL, 0),
SENSOR_ATTR(in1_input, S_IRUGO, adcxx_read, NULL, 1),
SENSOR_ATTR(in2_input, S_IRUGO, adcxx_read, NULL, 2),
SENSOR_ATTR(in3_input, S_IRUGO, adcxx_read, NULL, 3),
SENSOR_ATTR(in4_input, S_IRUGO, adcxx_read, NULL, 4),
SENSOR_ATTR(in5_input, S_IRUGO, adcxx_read, NULL, 5),
SENSOR_ATTR(in6_input, S_IRUGO, adcxx_read, NULL, 6),
SENSOR_ATTR(in7_input, S_IRUGO, adcxx_read, NULL, 7),
};
/*----------------------------------------------------------------------*/
static int __devinit adcxx_probe(struct spi_device *spi)
{
int channels = spi_get_device_id(spi)->driver_data;
struct adcxx *adc;
int status;
int i;
adc = kzalloc(sizeof *adc, GFP_KERNEL);
if (!adc)
return -ENOMEM;
/* set a default value for the reference */
adc->reference = 3300;
adc->channels = channels;
mutex_init(&adc->lock);
mutex_lock(&adc->lock);
dev_set_drvdata(&spi->dev, adc);
for (i = 0; i < 3 + adc->channels; i++) {
status = device_create_file(&spi->dev, &ad_input[i].dev_attr);
if (status) {
dev_err(&spi->dev, "device_create_file failed.\n");
goto out_err;
}
}
adc->hwmon_dev = hwmon_device_register(&spi->dev);
if (IS_ERR(adc->hwmon_dev)) {
dev_err(&spi->dev, "hwmon_device_register failed.\n");
status = PTR_ERR(adc->hwmon_dev);
goto out_err;
}
mutex_unlock(&adc->lock);
return 0;
out_err:
for (i--; i >= 0; i--)
device_remove_file(&spi->dev, &ad_input[i].dev_attr);
dev_set_drvdata(&spi->dev, NULL);
mutex_unlock(&adc->lock);
kfree(adc);
return status;
}
static int __devexit adcxx_remove(struct spi_device *spi)
{
struct adcxx *adc = dev_get_drvdata(&spi->dev);
int i;
mutex_lock(&adc->lock);
hwmon_device_unregister(adc->hwmon_dev);
for (i = 0; i < 3 + adc->channels; i++)
device_remove_file(&spi->dev, &ad_input[i].dev_attr);
dev_set_drvdata(&spi->dev, NULL);
mutex_unlock(&adc->lock);
kfree(adc);
return 0;
}
static const struct spi_device_id adcxx_ids[] = {
{ "adcxx1s", 1 },
{ "adcxx2s", 2 },
{ "adcxx4s", 4 },
{ "adcxx8s", 8 },
{ },
};
MODULE_DEVICE_TABLE(spi, adcxx_ids);
static struct spi_driver adcxx_driver = {
.driver = {
.name = "adcxx",
.owner = THIS_MODULE,
},
.id_table = adcxx_ids,
.probe = adcxx_probe,
.remove = __devexit_p(adcxx_remove),
};
static int __init init_adcxx(void)
{
return spi_register_driver(&adcxx_driver);
}
static void __exit exit_adcxx(void)
{
spi_unregister_driver(&adcxx_driver);
}
module_init(init_adcxx);
module_exit(exit_adcxx);
MODULE_AUTHOR("Marc Pignat");
MODULE_DESCRIPTION("National Semiconductor adcxx8sxxx Linux driver");
MODULE_LICENSE("GPL");
|