forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
293 lines
6.8 KiB
293 lines
6.8 KiB
// SPDX-License-Identifier: GPL-2.0-only |
|
/* |
|
* 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 <[email protected]> |
|
*/ |
|
|
|
#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 <[email protected]>"); |
|
MODULE_DESCRIPTION("MAX1110/MAX1111/MAX1112/MAX1113 ADC Driver"); |
|
MODULE_LICENSE("GPL");
|
|
|