| /* |
| * 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 = spi_get_drvdata(spi); |
| 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 = spi_get_drvdata(spi); |
| 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 = spi_get_drvdata(spi); |
| unsigned long value; |
| |
| if (kstrtoul(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) |
| { |
| return sprintf(buf, "%s\n", to_spi_device(dev)->modalias); |
| } |
| |
| 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 = devm_kzalloc(&spi->dev, 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); |
| |
| spi_set_drvdata(spi, 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); |
| |
| spi_set_drvdata(spi, NULL); |
| mutex_unlock(&adc->lock); |
| return status; |
| } |
| |
| static int __devexit adcxx_remove(struct spi_device *spi) |
| { |
| struct adcxx *adc = spi_get_drvdata(spi); |
| 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); |
| |
| spi_set_drvdata(spi, NULL); |
| mutex_unlock(&adc->lock); |
| |
| 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 = adcxx_remove, |
| }; |
| |
| module_spi_driver(adcxx_driver); |
| |
| MODULE_AUTHOR("Marc Pignat"); |
| MODULE_DESCRIPTION("National Semiconductor adcxx8sxxx Linux driver"); |
| MODULE_LICENSE("GPL"); |