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310 lines
9.1 KiB
310 lines
9.1 KiB
/*
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pcf8591.c - Part of lm_sensors, Linux kernel modules for hardware
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monitoring
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Copyright (C) 2001-2004 Aurelien Jarno <aurelien@aurel32.net>
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Ported to Linux 2.6 by Aurelien Jarno <aurelien@aurel32.net> with
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the help of Jean Delvare <khali@linux-fr.org>
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/i2c.h>
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/* Addresses to scan */
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static unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
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0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
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/* Insmod parameters */
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I2C_CLIENT_INSMOD_1(pcf8591);
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static int input_mode;
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module_param(input_mode, int, 0);
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MODULE_PARM_DESC(input_mode,
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"Analog input mode:\n"
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" 0 = four single ended inputs\n"
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" 1 = three differential inputs\n"
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" 2 = single ended and differential mixed\n"
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" 3 = two differential inputs\n");
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/* The PCF8591 control byte
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7 6 5 4 3 2 1 0
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| 0 |AOEF| AIP | 0 |AINC| AICH | */
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/* Analog Output Enable Flag (analog output active if 1) */
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#define PCF8591_CONTROL_AOEF 0x40
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/* Analog Input Programming
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0x00 = four single ended inputs
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0x10 = three differential inputs
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0x20 = single ended and differential mixed
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0x30 = two differential inputs */
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#define PCF8591_CONTROL_AIP_MASK 0x30
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/* Autoincrement Flag (switch on if 1) */
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#define PCF8591_CONTROL_AINC 0x04
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/* Channel selection
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0x00 = channel 0
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0x01 = channel 1
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0x02 = channel 2
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0x03 = channel 3 */
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#define PCF8591_CONTROL_AICH_MASK 0x03
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/* Initial values */
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#define PCF8591_INIT_CONTROL ((input_mode << 4) | PCF8591_CONTROL_AOEF)
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#define PCF8591_INIT_AOUT 0 /* DAC out = 0 */
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/* Conversions */
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#define REG_TO_SIGNED(reg) (((reg) & 0x80)?((reg) - 256):(reg))
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struct pcf8591_data {
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struct i2c_client client;
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struct semaphore update_lock;
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u8 control;
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u8 aout;
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};
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static int pcf8591_attach_adapter(struct i2c_adapter *adapter);
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static int pcf8591_detect(struct i2c_adapter *adapter, int address, int kind);
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static int pcf8591_detach_client(struct i2c_client *client);
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static void pcf8591_init_client(struct i2c_client *client);
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static int pcf8591_read_channel(struct device *dev, int channel);
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/* This is the driver that will be inserted */
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static struct i2c_driver pcf8591_driver = {
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.owner = THIS_MODULE,
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.name = "pcf8591",
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.id = I2C_DRIVERID_PCF8591,
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.flags = I2C_DF_NOTIFY,
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.attach_adapter = pcf8591_attach_adapter,
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.detach_client = pcf8591_detach_client,
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};
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/* following are the sysfs callback functions */
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#define show_in_channel(channel) \
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static ssize_t show_in##channel##_input(struct device *dev, struct device_attribute *attr, char *buf) \
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{ \
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return sprintf(buf, "%d\n", pcf8591_read_channel(dev, channel));\
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} \
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static DEVICE_ATTR(in##channel##_input, S_IRUGO, \
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show_in##channel##_input, NULL);
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show_in_channel(0);
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show_in_channel(1);
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show_in_channel(2);
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show_in_channel(3);
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static ssize_t show_out0_ouput(struct device *dev, struct device_attribute *attr, char *buf)
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{
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struct pcf8591_data *data = i2c_get_clientdata(to_i2c_client(dev));
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return sprintf(buf, "%d\n", data->aout * 10);
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}
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static ssize_t set_out0_output(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
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{
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unsigned int value;
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struct i2c_client *client = to_i2c_client(dev);
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struct pcf8591_data *data = i2c_get_clientdata(client);
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if ((value = (simple_strtoul(buf, NULL, 10) + 5) / 10) <= 255) {
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data->aout = value;
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i2c_smbus_write_byte_data(client, data->control, data->aout);
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return count;
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}
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return -EINVAL;
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}
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static DEVICE_ATTR(out0_output, S_IWUSR | S_IRUGO,
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show_out0_ouput, set_out0_output);
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static ssize_t show_out0_enable(struct device *dev, struct device_attribute *attr, char *buf)
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{
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struct pcf8591_data *data = i2c_get_clientdata(to_i2c_client(dev));
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return sprintf(buf, "%u\n", !(!(data->control & PCF8591_CONTROL_AOEF)));
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}
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static ssize_t set_out0_enable(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
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{
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struct i2c_client *client = to_i2c_client(dev);
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struct pcf8591_data *data = i2c_get_clientdata(client);
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unsigned long val = simple_strtoul(buf, NULL, 10);
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down(&data->update_lock);
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if (val)
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data->control |= PCF8591_CONTROL_AOEF;
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else
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data->control &= ~PCF8591_CONTROL_AOEF;
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i2c_smbus_write_byte(client, data->control);
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up(&data->update_lock);
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return count;
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}
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static DEVICE_ATTR(out0_enable, S_IWUSR | S_IRUGO,
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show_out0_enable, set_out0_enable);
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/*
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* Real code
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*/
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static int pcf8591_attach_adapter(struct i2c_adapter *adapter)
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{
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return i2c_probe(adapter, &addr_data, pcf8591_detect);
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}
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/* This function is called by i2c_probe */
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static int pcf8591_detect(struct i2c_adapter *adapter, int address, int kind)
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{
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struct i2c_client *new_client;
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struct pcf8591_data *data;
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int err = 0;
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if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE
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| I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
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goto exit;
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/* OK. For now, we presume we have a valid client. We now create the
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client structure, even though we cannot fill it completely yet. */
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if (!(data = kzalloc(sizeof(struct pcf8591_data), GFP_KERNEL))) {
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err = -ENOMEM;
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goto exit;
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}
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new_client = &data->client;
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i2c_set_clientdata(new_client, data);
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new_client->addr = address;
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new_client->adapter = adapter;
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new_client->driver = &pcf8591_driver;
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new_client->flags = 0;
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/* Now, we would do the remaining detection. But the PCF8591 is plainly
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impossible to detect! Stupid chip. */
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/* Determine the chip type - only one kind supported! */
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if (kind <= 0)
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kind = pcf8591;
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/* Fill in the remaining client fields and put it into the global
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list */
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strlcpy(new_client->name, "pcf8591", I2C_NAME_SIZE);
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init_MUTEX(&data->update_lock);
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/* Tell the I2C layer a new client has arrived */
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if ((err = i2c_attach_client(new_client)))
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goto exit_kfree;
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/* Initialize the PCF8591 chip */
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pcf8591_init_client(new_client);
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/* Register sysfs hooks */
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device_create_file(&new_client->dev, &dev_attr_out0_enable);
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device_create_file(&new_client->dev, &dev_attr_out0_output);
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device_create_file(&new_client->dev, &dev_attr_in0_input);
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device_create_file(&new_client->dev, &dev_attr_in1_input);
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/* Register input2 if not in "two differential inputs" mode */
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if (input_mode != 3 )
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device_create_file(&new_client->dev, &dev_attr_in2_input);
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/* Register input3 only in "four single ended inputs" mode */
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if (input_mode == 0)
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device_create_file(&new_client->dev, &dev_attr_in3_input);
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return 0;
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/* OK, this is not exactly good programming practice, usually. But it is
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very code-efficient in this case. */
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exit_kfree:
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kfree(data);
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exit:
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return err;
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}
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static int pcf8591_detach_client(struct i2c_client *client)
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{
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int err;
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if ((err = i2c_detach_client(client)))
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return err;
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kfree(i2c_get_clientdata(client));
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return 0;
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}
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/* Called when we have found a new PCF8591. */
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static void pcf8591_init_client(struct i2c_client *client)
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{
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struct pcf8591_data *data = i2c_get_clientdata(client);
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data->control = PCF8591_INIT_CONTROL;
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data->aout = PCF8591_INIT_AOUT;
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i2c_smbus_write_byte_data(client, data->control, data->aout);
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/* The first byte transmitted contains the conversion code of the
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previous read cycle. FLUSH IT! */
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i2c_smbus_read_byte(client);
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}
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static int pcf8591_read_channel(struct device *dev, int channel)
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{
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u8 value;
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struct i2c_client *client = to_i2c_client(dev);
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struct pcf8591_data *data = i2c_get_clientdata(client);
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down(&data->update_lock);
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if ((data->control & PCF8591_CONTROL_AICH_MASK) != channel) {
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data->control = (data->control & ~PCF8591_CONTROL_AICH_MASK)
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| channel;
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i2c_smbus_write_byte(client, data->control);
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/* The first byte transmitted contains the conversion code of
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the previous read cycle. FLUSH IT! */
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i2c_smbus_read_byte(client);
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}
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value = i2c_smbus_read_byte(client);
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up(&data->update_lock);
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if ((channel == 2 && input_mode == 2) ||
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(channel != 3 && (input_mode == 1 || input_mode == 3)))
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return (10 * REG_TO_SIGNED(value));
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else
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return (10 * value);
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}
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static int __init pcf8591_init(void)
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{
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if (input_mode < 0 || input_mode > 3) {
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printk(KERN_WARNING "pcf8591: invalid input_mode (%d)\n",
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input_mode);
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input_mode = 0;
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}
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return i2c_add_driver(&pcf8591_driver);
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}
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static void __exit pcf8591_exit(void)
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{
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i2c_del_driver(&pcf8591_driver);
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}
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MODULE_AUTHOR("Aurelien Jarno <aurelien@aurel32.net>");
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MODULE_DESCRIPTION("PCF8591 driver");
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MODULE_LICENSE("GPL");
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module_init(pcf8591_init);
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module_exit(pcf8591_exit);
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