/*
* ad525x_dpot: Driver for the Analog Devices digital potentiometers
* Copyright (c) 2009-2010 Analog Devices, Inc.
* Author: Michael Hennerich <hennerich@blackfin.uclinux.org>
*
* DEVID #Wipers #Positions Resistor Options (kOhm)
* AD5258 1 64 1, 10, 50, 100
* AD5259 1 256 5, 10, 50, 100
* AD5251 2 64 1, 10, 50, 100
* AD5252 2 256 1, 10, 50, 100
* AD5255 3 512 25, 250
* AD5253 4 64 1, 10, 50, 100
* AD5254 4 256 1, 10, 50, 100
* AD5160 1 256 5, 10, 50, 100
* AD5161 1 256 5, 10, 50, 100
* AD5162 2 256 2.5, 10, 50, 100
* AD5165 1 256 100
* AD5200 1 256 10, 50
* AD5201 1 33 10, 50
* AD5203 4 64 10, 100
* AD5204 4 256 10, 50, 100
* AD5206 6 256 10, 50, 100
* AD5207 2 256 10, 50, 100
* AD5231 1 1024 10, 50, 100
* AD5232 2 256 10, 50, 100
* AD5233 4 64 10, 50, 100
* AD5235 2 1024 25, 250
* AD5260 1 256 20, 50, 200
* AD5262 2 256 20, 50, 200
* AD5263 4 256 20, 50, 200
* AD5290 1 256 10, 50, 100
* AD5291 1 256 20
* AD5292 1 1024 20
* AD5293 1 1024 20
* AD7376 1 128 10, 50, 100, 1M
* AD8400 1 256 1, 10, 50, 100
* AD8402 2 256 1, 10, 50, 100
* AD8403 4 256 1, 10, 50, 100
* ADN2850 3 512 25, 250
*
* See Documentation/misc-devices/ad525x_dpot.txt for more info.
*
* derived from ad5258.c
* Copyright (c) 2009 Cyber Switching, Inc.
* Author: Chris Verges <chrisv@cyberswitching.com>
*
* derived from ad5252.c
* Copyright (c) 2006 Michael Hennerich <hennerich@blackfin.uclinux.org>
*
* Licensed under the GPL-2 or later.
*/
#include <linux/module.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/slab.h>
#define DRIVER_VERSION "0.2"
#include "ad525x_dpot.h"
/*
* Client data (each client gets its own)
*/
struct dpot_data {
struct ad_dpot_bus_data bdata;
struct mutex update_lock;
unsigned rdac_mask;
unsigned max_pos;
unsigned long devid;
unsigned uid;
unsigned feat;
unsigned wipers;
u16 rdac_cache[8];
};
static inline int dpot_read_d8(struct dpot_data *dpot)
{
return dpot->bdata.bops->read_d8(dpot->bdata.client);
}
static inline int dpot_read_r8d8(struct dpot_data *dpot, u8 reg)
{
return dpot->bdata.bops->read_r8d8(dpot->bdata.client, reg);
}
static inline int dpot_read_r8d16(struct dpot_data *dpot, u8 reg)
{
return dpot->bdata.bops->read_r8d16(dpot->bdata.client, reg);
}
static inline int dpot_write_d8(struct dpot_data *dpot, u8 val)
{
return dpot->bdata.bops->write_d8(dpot->bdata.client, val);
}
static inline int dpot_write_r8d8(struct dpot_data *dpot, u8 reg, u16 val)
{
return dpot->bdata.bops->write_r8d8(dpot->bdata.client, reg, val);
}
static inline int dpot_write_r8d16(struct dpot_data *dpot, u8 reg, u16 val)
{
return dpot->bdata.bops->write_r8d16(dpot->bdata.client, reg, val);
}
static s32 dpot_read(struct dpot_data *dpot, u8 reg)
{
unsigned val = 0;
if (dpot->feat & F_SPI) {
if (!(reg & (DPOT_ADDR_EEPROM | DPOT_ADDR_CMD))) {
if (dpot->feat & F_RDACS_WONLY)
return dpot->rdac_cache[reg & DPOT_RDAC_MASK];
if (dpot->uid == DPOT_UID(AD5291_ID) ||
dpot->uid == DPOT_UID(AD5292_ID) ||
dpot->uid == DPOT_UID(AD5293_ID))
return dpot_read_r8d8(dpot,
DPOT_AD5291_READ_RDAC << 2);
val = DPOT_SPI_READ_RDAC;
} else if (reg & DPOT_ADDR_EEPROM) {
val = DPOT_SPI_READ_EEPROM;
}
if (dpot->feat & F_SPI_16BIT)
return dpot_read_r8d8(dpot, val);
else if (dpot->feat & F_SPI_24BIT)
return dpot_read_r8d16(dpot, val);
} else { /* I2C */
if ((reg & DPOT_REG_TOL) || (dpot->max_pos > 256))
return dpot_read_r8d16(dpot, (reg & 0xF8) |
((reg & 0x7) << 1));
else
return dpot_read_r8d8(dpot, reg);
}
return -EFAULT;
}
static s32 dpot_write(struct dpot_data *dpot, u8 reg, u16 value)
{
unsigned val = 0;
if (dpot->feat & F_SPI) {
if (!(reg & (DPOT_ADDR_EEPROM | DPOT_ADDR_CMD))) {
if (dpot->feat & F_RDACS_WONLY)
dpot->rdac_cache[reg & DPOT_RDAC_MASK] = value;
if (dpot->feat & F_AD_APPDATA) {
if (dpot->feat & F_SPI_8BIT) {
val = ((reg & DPOT_RDAC_MASK) <<
DPOT_MAX_POS(dpot->devid)) |
value;
return dpot_write_d8(dpot, val);
} else if (dpot->feat & F_SPI_16BIT) {
val = ((reg & DPOT_RDAC_MASK) <<
DPOT_MAX_POS(dpot->devid)) |
value;
return dpot_write_r8d8(dpot, val >> 8,
val & 0xFF);
} else
BUG();
} else {
if (dpot->uid == DPOT_UID(AD5291_ID) ||
dpot->uid == DPOT_UID(AD5292_ID) ||
dpot->uid == DPOT_UID(AD5293_ID))
return dpot_write_r8d8(dpot,
(DPOT_AD5291_RDAC << 2) |
(value >> 8), value & 0xFF);
val = DPOT_SPI_RDAC | (reg & DPOT_RDAC_MASK);
}
} else if (reg & DPOT_ADDR_EEPROM) {
val = DPOT_SPI_EEPROM | (reg & DPOT_RDAC_MASK);
} else if (reg & DPOT_ADDR_CMD) {
switch (reg) {
case DPOT_DEC_ALL_6DB:
val = DPOT_SPI_DEC_ALL_6DB;
break;
case DPOT_INC_ALL_6DB:
val = DPOT_SPI_INC_ALL_6DB;
break;
case DPOT_DEC_ALL:
val = DPOT_SPI_DEC_ALL;
break;
case DPOT_INC_ALL:
val = DPOT_SPI_INC_ALL;
break;
}
} else
BUG();
if (dpot->feat & F_SPI_16BIT)
return dpot_write_r8d8(dpot, val, value);
else if (dpot->feat & F_SPI_24BIT)
return dpot_write_r8d16(dpot, val, value);
} else {
/* Only write the instruction byte for certain commands */
if (reg & DPOT_ADDR_CMD)
return dpot_write_d8(dpot, reg);
if (dpot->max_pos > 256)
return dpot_write_r8d16(dpot, (reg & 0xF8) |
((reg & 0x7) << 1), value);
else
/* All other registers require instruction + data bytes */
return dpot_write_r8d8(dpot, reg, value);
}
return -EFAULT;
}
/* sysfs functions */
static ssize_t sysfs_show_reg(struct device *dev,
struct device_attribute *attr,
char *buf, u32 reg)
{
struct dpot_data *data = dev_get_drvdata(dev);
s32 value;
mutex_lock(&data->update_lock);
value = dpot_read(data, reg);
mutex_unlock(&data->update_lock);
if (value < 0)
return -EINVAL;
/*
* Let someone else deal with converting this ...
* the tolerance is a two-byte value where the MSB
* is a sign + integer value, and the LSB is a
* decimal value. See page 18 of the AD5258
* datasheet (Rev. A) for more details.
*/
if (reg & DPOT_REG_TOL)
return sprintf(buf, "0x%04x\n", value & 0xFFFF);
else
return sprintf(buf, "%u\n", value & data->rdac_mask);
}
static ssize_t sysfs_set_reg(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count, u32 reg)
{
struct dpot_data *data = dev_get_drvdata(dev);
unsigned long value;
int err;
err = strict_strtoul(buf, 10, &value);
if (err)
return err;
if (value > data->rdac_mask)
value = data->rdac_mask;
mutex_lock(&data->update_lock);
dpot_write(data, reg, value);
if (reg & DPOT_ADDR_EEPROM)
msleep(26); /* Sleep while the EEPROM updates */
mutex_unlock(&data->update_lock);
return count;
}
static ssize_t sysfs_do_cmd(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count, u32 reg)
{
struct dpot_data *data = dev_get_drvdata(dev);
mutex_lock(&data->update_lock);
dpot_write(data, reg, 0);
mutex_unlock(&data->update_lock);
return count;
}
/* ------------------------------------------------------------------------- */
#define DPOT_DEVICE_SHOW(_name, _reg) static ssize_t \
show_##_name(struct device *dev, \
struct device_attribute *attr, char *buf) \
{ \
return sysfs_show_reg(dev, attr, buf, _reg); \
}
#define DPOT_DEVICE_SET(_name, _reg) static ssize_t \
set_##_name(struct device *dev, \
struct device_attribute *attr, \
const char *buf, size_t count) \
{ \
return sysfs_set_reg(dev, attr, buf, count, _reg); \
}
#define DPOT_DEVICE_SHOW_SET(name, reg) \
DPOT_DEVICE_SHOW(name, reg) \
DPOT_DEVICE_SET(name, reg) \
static DEVICE_ATTR(name, S_IWUSR | S_IRUGO, show_##name, set_##name);
#define DPOT_DEVICE_SHOW_ONLY(name, reg) \
DPOT_DEVICE_SHOW(name, reg) \
static DEVICE_ATTR(name, S_IWUSR | S_IRUGO, show_##name, NULL);
DPOT_DEVICE_SHOW_SET(rdac0, DPOT_ADDR_RDAC | DPOT_RDAC0);
DPOT_DEVICE_SHOW_SET(eeprom0, DPOT_ADDR_EEPROM | DPOT_RDAC0);
DPOT_DEVICE_SHOW_ONLY(tolerance0, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC0);
DPOT_DEVICE_SHOW_SET(rdac1, DPOT_ADDR_RDAC | DPOT_RDAC1);
DPOT_DEVICE_SHOW_SET(eeprom1, DPOT_ADDR_EEPROM | DPOT_RDAC1);
DPOT_DEVICE_SHOW_ONLY(tolerance1, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC1);
DPOT_DEVICE_SHOW_SET(rdac2, DPOT_ADDR_RDAC | DPOT_RDAC2);
DPOT_DEVICE_SHOW_SET(eeprom2, DPOT_ADDR_EEPROM | DPOT_RDAC2);
DPOT_DEVICE_SHOW_ONLY(tolerance2, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC2);
DPOT_DEVICE_SHOW_SET(rdac3, DPOT_ADDR_RDAC | DPOT_RDAC3);
DPOT_DEVICE_SHOW_SET(eeprom3, DPOT_ADDR_EEPROM | DPOT_RDAC3);
DPOT_DEVICE_SHOW_ONLY(tolerance3, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC3);
DPOT_DEVICE_SHOW_SET(rdac4, DPOT_ADDR_RDAC | DPOT_RDAC4);
DPOT_DEVICE_SHOW_SET(eeprom4, DPOT_ADDR_EEPROM | DPOT_RDAC4);
DPOT_DEVICE_SHOW_ONLY(tolerance4, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC4);
DPOT_DEVICE_SHOW_SET(rdac5, DPOT_ADDR_RDAC | DPOT_RDAC5);
DPOT_DEVICE_SHOW_SET(eeprom5, DPOT_ADDR_EEPROM | DPOT_RDAC5);
DPOT_DEVICE_SHOW_ONLY(tolerance5, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC5);
static const struct attribute *dpot_attrib_wipers[] = {
&dev_attr_rdac0.attr,
&dev_attr_rdac1.attr,
&dev_attr_rdac2.attr,
&dev_attr_rdac3.attr,
&dev_attr_rdac4.attr,
&dev_attr_rdac5.attr,
NULL
};
static const struct attribute *dpot_attrib_eeprom[] = {
&dev_attr_eeprom0.attr,
&dev_attr_eeprom1.attr,
&dev_attr_eeprom2.attr,
&dev_attr_eeprom3.attr,
&dev_attr_eeprom4.attr,
&dev_attr_eeprom5.attr,
NULL
};
static const struct attribute *dpot_attrib_tolerance[] = {
&dev_attr_tolerance0.attr,
&dev_attr_tolerance1.attr,
&dev_attr_tolerance2.attr,
&dev_attr_tolerance3.attr,
&dev_attr_tolerance4.attr,
&dev_attr_tolerance5.attr,
NULL
};
/* ------------------------------------------------------------------------- */
#define DPOT_DEVICE_DO_CMD(_name, _cmd) static ssize_t \
set_##_name(struct device *dev, \
struct device_attribute *attr, \
const char *buf, size_t count) \
{ \
return sysfs_do_cmd(dev, attr, buf, count, _cmd); \
} \
static DEVICE_ATTR(_name, S_IWUSR | S_IRUGO, NULL, set_##_name);
DPOT_DEVICE_DO_CMD(inc_all, DPOT_INC_ALL);
DPOT_DEVICE_DO_CMD(dec_all, DPOT_DEC_ALL);
DPOT_DEVICE_DO_CMD(inc_all_6db, DPOT_INC_ALL_6DB);
DPOT_DEVICE_DO_CMD(dec_all_6db, DPOT_DEC_ALL_6DB);
static struct attribute *ad525x_attributes_commands[] = {
&dev_attr_inc_all.attr,
&dev_attr_dec_all.attr,
&dev_attr_inc_all_6db.attr,
&dev_attr_dec_all_6db.attr,
NULL
};
static const struct attribute_group ad525x_group_commands = {
.attrs = ad525x_attributes_commands,
};
__devinit int ad_dpot_add_files(struct device *dev,
unsigned features, unsigned rdac)
{
int err = sysfs_create_file(&dev->kobj,
dpot_attrib_wipers[rdac]);
if (features & F_CMD_EEP)
err |= sysfs_create_file(&dev->kobj,
dpot_attrib_eeprom[rdac]);
if (features & F_CMD_TOL)
err |= sysfs_create_file(&dev->kobj,
dpot_attrib_tolerance[rdac]);
if (err)
dev_err(dev, "failed to register sysfs hooks for RDAC%d\n",
rdac);
return err;
}
inline void ad_dpot_remove_files(struct device *dev,
unsigned features, unsigned rdac)
{
sysfs_remove_file(&dev->kobj,
dpot_attrib_wipers[rdac]);
if (features & F_CMD_EEP)
sysfs_remove_file(&dev->kobj,
dpot_attrib_eeprom[rdac]);
if (features & F_CMD_TOL)
sysfs_remove_file(&dev->kobj,
dpot_attrib_tolerance[rdac]);
}
__devinit int ad_dpot_probe(struct device *dev,
struct ad_dpot_bus_data *bdata, const struct ad_dpot_id *id)
{
struct dpot_data *data;
int i, err = 0;
data = kzalloc(sizeof(struct dpot_data), GFP_KERNEL);
if (!data) {
err = -ENOMEM;
goto exit;
}
dev_set_drvdata(dev, data);
mutex_init(&data->update_lock);
data->bdata = *bdata;
data->devid = id->devid;
data->max_pos = 1 << DPOT_MAX_POS(data->devid);
data->rdac_mask = data->max_pos - 1;
data->feat = DPOT_FEAT(data->devid);
data->uid = DPOT_UID(data->devid);
data->wipers = DPOT_WIPERS(data->devid);
for (i = DPOT_RDAC0; i <= DPOT_RDAC5; i++)
if (data->wipers & (1 << i)) {
err = ad_dpot_add_files(dev, data->feat, i);
if (err)
goto exit_remove_files;
/* power-up midscale */
if (data->feat & F_RDACS_WONLY)
data->rdac_cache[i] = data->max_pos / 2;
}
if (data->feat & F_CMD_INC)
err = sysfs_create_group(&dev->kobj, &ad525x_group_commands);
if (err) {
dev_err(dev, "failed to register sysfs hooks\n");
goto exit_free;
}
dev_info(dev, "%s %d-Position Digital Potentiometer registered\n",
id->name, data->max_pos);
return 0;
exit_remove_files:
for (i = DPOT_RDAC0; i <= DPOT_RDAC5; i++)
if (data->wipers & (1 << i))
ad_dpot_remove_files(dev, data->feat, i);
exit_free:
kfree(data);
dev_set_drvdata(dev, NULL);
exit:
dev_err(dev, "failed to create client for %s ID 0x%lX\n",
id->name, id->devid);
return err;
}
EXPORT_SYMBOL(ad_dpot_probe);
__devexit int ad_dpot_remove(struct device *dev)
{
struct dpot_data *data = dev_get_drvdata(dev);
int i;
for (i = DPOT_RDAC0; i <= DPOT_RDAC5; i++)
if (data->wipers & (1 << i))
ad_dpot_remove_files(dev, data->feat, i);
kfree(data);
return 0;
}
EXPORT_SYMBOL(ad_dpot_remove);
MODULE_AUTHOR("Chris Verges <chrisv@cyberswitching.com>, "
"Michael Hennerich <hennerich@blackfin.uclinux.org>");
MODULE_DESCRIPTION("Digital potentiometer driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRIVER_VERSION);
