linux/drivers/hwmon/max1111.c
Julia Lawall 17c45c4d06 hwmon: (max1111) use permission-specific DEVICE_ATTR variants
Use DEVICE_ATTR_RO for read-only attributes. This simplifies the source
code, improves readbility, and reduces the chance of inconsistencies.

The conversion was done automatically using coccinelle. It was validated
by compiling both the old and the new source code and comparing its text,
data, and bss size.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
[groeck: Updated description]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2017-01-02 10:19:45 -08:00

297 lines
7.0 KiB
C

/*
* max1111.c - +2.7V, Low-Power, Multichannel, Serial 8-bit ADCs
*
* Based on arch/arm/mach-pxa/corgi_ssp.c
*
* Copyright (C) 2004-2005 Richard Purdie
*
* Copyright (C) 2008 Marvell International Ltd.
* Eric Miao <eric.miao@marvell.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* publishhed by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/spi/spi.h>
#include <linux/slab.h>
enum chips { max1110, max1111, max1112, max1113 };
#define MAX1111_TX_BUF_SIZE 1
#define MAX1111_RX_BUF_SIZE 2
/* MAX1111 Commands */
#define MAX1111_CTRL_PD0 (1u << 0)
#define MAX1111_CTRL_PD1 (1u << 1)
#define MAX1111_CTRL_SGL (1u << 2)
#define MAX1111_CTRL_UNI (1u << 3)
#define MAX1110_CTRL_SEL_SH (4)
#define MAX1111_CTRL_SEL_SH (5) /* NOTE: bit 4 is ignored */
#define MAX1111_CTRL_STR (1u << 7)
struct max1111_data {
struct spi_device *spi;
struct device *hwmon_dev;
struct spi_message msg;
struct spi_transfer xfer[2];
uint8_t tx_buf[MAX1111_TX_BUF_SIZE];
uint8_t rx_buf[MAX1111_RX_BUF_SIZE];
struct mutex drvdata_lock;
/* protect msg, xfer and buffers from multiple access */
int sel_sh;
int lsb;
};
static int max1111_read(struct device *dev, int channel)
{
struct max1111_data *data = dev_get_drvdata(dev);
uint8_t v1, v2;
int err;
/* writing to drvdata struct is not thread safe, wait on mutex */
mutex_lock(&data->drvdata_lock);
data->tx_buf[0] = (channel << data->sel_sh) |
MAX1111_CTRL_PD0 | MAX1111_CTRL_PD1 |
MAX1111_CTRL_SGL | MAX1111_CTRL_UNI | MAX1111_CTRL_STR;
err = spi_sync(data->spi, &data->msg);
if (err < 0) {
dev_err(dev, "spi_sync failed with %d\n", err);
mutex_unlock(&data->drvdata_lock);
return err;
}
v1 = data->rx_buf[0];
v2 = data->rx_buf[1];
mutex_unlock(&data->drvdata_lock);
if ((v1 & 0xc0) || (v2 & 0x3f))
return -EINVAL;
return (v1 << 2) | (v2 >> 6);
}
#ifdef CONFIG_SHARPSL_PM
static struct max1111_data *the_max1111;
int max1111_read_channel(int channel)
{
if (!the_max1111 || !the_max1111->spi)
return -ENODEV;
return max1111_read(&the_max1111->spi->dev, channel);
}
EXPORT_SYMBOL(max1111_read_channel);
#endif
/*
* NOTE: SPI devices do not have a default 'name' attribute, which is
* likely to be used by hwmon applications to distinguish between
* different devices, explicitly add a name attribute here.
*/
static ssize_t name_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
return sprintf(buf, "%s\n", to_spi_device(dev)->modalias);
}
static ssize_t show_adc(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct max1111_data *data = dev_get_drvdata(dev);
int channel = to_sensor_dev_attr(attr)->index;
int ret;
ret = max1111_read(dev, channel);
if (ret < 0)
return ret;
/*
* Assume the reference voltage to be 2.048V or 4.096V, with an 8-bit
* sample. The LSB weight is 8mV or 16mV depending on the chip type.
*/
return sprintf(buf, "%d\n", ret * data->lsb);
}
#define MAX1111_ADC_ATTR(_id) \
SENSOR_DEVICE_ATTR(in##_id##_input, S_IRUGO, show_adc, NULL, _id)
static DEVICE_ATTR_RO(name);
static MAX1111_ADC_ATTR(0);
static MAX1111_ADC_ATTR(1);
static MAX1111_ADC_ATTR(2);
static MAX1111_ADC_ATTR(3);
static MAX1111_ADC_ATTR(4);
static MAX1111_ADC_ATTR(5);
static MAX1111_ADC_ATTR(6);
static MAX1111_ADC_ATTR(7);
static struct attribute *max1111_attributes[] = {
&dev_attr_name.attr,
&sensor_dev_attr_in0_input.dev_attr.attr,
&sensor_dev_attr_in1_input.dev_attr.attr,
&sensor_dev_attr_in2_input.dev_attr.attr,
&sensor_dev_attr_in3_input.dev_attr.attr,
NULL,
};
static const struct attribute_group max1111_attr_group = {
.attrs = max1111_attributes,
};
static struct attribute *max1110_attributes[] = {
&sensor_dev_attr_in4_input.dev_attr.attr,
&sensor_dev_attr_in5_input.dev_attr.attr,
&sensor_dev_attr_in6_input.dev_attr.attr,
&sensor_dev_attr_in7_input.dev_attr.attr,
NULL,
};
static const struct attribute_group max1110_attr_group = {
.attrs = max1110_attributes,
};
static int setup_transfer(struct max1111_data *data)
{
struct spi_message *m;
struct spi_transfer *x;
m = &data->msg;
x = &data->xfer[0];
spi_message_init(m);
x->tx_buf = &data->tx_buf[0];
x->len = MAX1111_TX_BUF_SIZE;
spi_message_add_tail(x, m);
x++;
x->rx_buf = &data->rx_buf[0];
x->len = MAX1111_RX_BUF_SIZE;
spi_message_add_tail(x, m);
return 0;
}
static int max1111_probe(struct spi_device *spi)
{
enum chips chip = spi_get_device_id(spi)->driver_data;
struct max1111_data *data;
int err;
spi->bits_per_word = 8;
spi->mode = SPI_MODE_0;
err = spi_setup(spi);
if (err < 0)
return err;
data = devm_kzalloc(&spi->dev, sizeof(struct max1111_data), GFP_KERNEL);
if (data == NULL)
return -ENOMEM;
switch (chip) {
case max1110:
data->lsb = 8;
data->sel_sh = MAX1110_CTRL_SEL_SH;
break;
case max1111:
data->lsb = 8;
data->sel_sh = MAX1111_CTRL_SEL_SH;
break;
case max1112:
data->lsb = 16;
data->sel_sh = MAX1110_CTRL_SEL_SH;
break;
case max1113:
data->lsb = 16;
data->sel_sh = MAX1111_CTRL_SEL_SH;
break;
}
err = setup_transfer(data);
if (err)
return err;
mutex_init(&data->drvdata_lock);
data->spi = spi;
spi_set_drvdata(spi, data);
err = sysfs_create_group(&spi->dev.kobj, &max1111_attr_group);
if (err) {
dev_err(&spi->dev, "failed to create attribute group\n");
return err;
}
if (chip == max1110 || chip == max1112) {
err = sysfs_create_group(&spi->dev.kobj, &max1110_attr_group);
if (err) {
dev_err(&spi->dev,
"failed to create extended attribute group\n");
goto err_remove;
}
}
data->hwmon_dev = hwmon_device_register(&spi->dev);
if (IS_ERR(data->hwmon_dev)) {
dev_err(&spi->dev, "failed to create hwmon device\n");
err = PTR_ERR(data->hwmon_dev);
goto err_remove;
}
#ifdef CONFIG_SHARPSL_PM
the_max1111 = data;
#endif
return 0;
err_remove:
sysfs_remove_group(&spi->dev.kobj, &max1110_attr_group);
sysfs_remove_group(&spi->dev.kobj, &max1111_attr_group);
return err;
}
static int max1111_remove(struct spi_device *spi)
{
struct max1111_data *data = spi_get_drvdata(spi);
#ifdef CONFIG_SHARPSL_PM
the_max1111 = NULL;
#endif
hwmon_device_unregister(data->hwmon_dev);
sysfs_remove_group(&spi->dev.kobj, &max1110_attr_group);
sysfs_remove_group(&spi->dev.kobj, &max1111_attr_group);
mutex_destroy(&data->drvdata_lock);
return 0;
}
static const struct spi_device_id max1111_ids[] = {
{ "max1110", max1110 },
{ "max1111", max1111 },
{ "max1112", max1112 },
{ "max1113", max1113 },
{ },
};
MODULE_DEVICE_TABLE(spi, max1111_ids);
static struct spi_driver max1111_driver = {
.driver = {
.name = "max1111",
},
.id_table = max1111_ids,
.probe = max1111_probe,
.remove = max1111_remove,
};
module_spi_driver(max1111_driver);
MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>");
MODULE_DESCRIPTION("MAX1110/MAX1111/MAX1112/MAX1113 ADC Driver");
MODULE_LICENSE("GPL");