Hi Wolfram,
On Tue, 2 Feb 2010 21:32:38 +0100, Wolfram Sang wrote:
> Add initial support for the ADT7411. Reads out all conversion results (via I2C,
> SPI yet missing) and allows some on-the-fly configuration. Tested with a custom
> board.
>
> Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
> Signed-off-by: Wolfram Sang <w.sang@xxxxxxxxxxxxxx>
> Cc: Jean Delvare <khali@xxxxxxxxxxxx>
> ---
>
> Changes since V1:
>
> * simplified reading 10-bit, no retries
> * modifying a configuration bit is now protected
> * no initial configuration is performed except START
> (which is what the other ADT drivers do)
> * when vdd is the reference, use a cached value for it
> * added a detect mechanism
> * style issues and typos found by Jean were fixed
>
> Documentation/hwmon/adt7411 | 42 +++++
> drivers/hwmon/Kconfig | 10 ++
> drivers/hwmon/Makefile | 1 +
> drivers/hwmon/adt7411.c | 361 +++++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 414 insertions(+), 0 deletions(-)
> create mode 100644 Documentation/hwmon/adt7411
> create mode 100644 drivers/hwmon/adt7411.c
Review:
>
> diff --git a/Documentation/hwmon/adt7411 b/Documentation/hwmon/adt7411
> new file mode 100644
> index 0000000..5571e56
> --- /dev/null
> +++ b/Documentation/hwmon/adt7411
> @@ -0,0 +1,42 @@
> +Kernel driver adt7411
> +=====================
> +
> +Supported chips:
> + * Analog Devices ADT7411
> + Prefix: 'adt7411'
> + Addresses scanned: 0x48, 0x4a, 0x4b
> + Datasheet: Publicly available at the Analog Devices website
> +
> +Author: Wolfram Sang (based on adt7470 by Darrick J. Wong)
> +
> +Description
> +-----------
> +
> +This driver implements support for the Analog Devices ADT7411 chip. There may
> +be other chips that implement this interface.
> +
> +The ADT7411 can use an I2C/SMBus compatible 2-wire interface or an
> +SPI-compatible 4-wire interface. It provides a 10-bit analog to digital
> +converter which measures 1 temperature, vdd and 8 input voltages. It has an
> +internal temperature sensor, but an external one can also be connected (one
> +loses 2 inputs then). There are high- and low-limit registers for all inputs.
> +
> +Check the datasheet for details.
> +
> +sysfs-Interface
> +---------------
> +
> +in0_input - vdd voltage input
> +in[1-8]_input - analog 1-8 input
> +temp1_input - temperature input
> +
> +Besides standard interfaces, this driver adds (0 = off, 1 = on):
> +
> + adc_ref_vdd - Use vdd as reference instead of 2.25 V
> + fast_sampling - Sample at 22.5 kHz instead of 1.4 kHz, but drop filters
> + no_average - Turn off averaging over 16 samples
> +
> +Notes
> +-----
> +
> +SPI, external temperature sensor and limit-registers are not supported yet.
No dash needed between limit and registers.
> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> index 68cf877..c91dc98 100644
> --- a/drivers/hwmon/Kconfig
> +++ b/drivers/hwmon/Kconfig
> @@ -170,6 +170,16 @@ config SENSORS_ADM9240
> This driver can also be built as a module. If so, the module
> will be called adm9240.
>
> +config SENSORS_ADT7411
> + tristate "Analog Devices ADT7411"
> + depends on I2C && EXPERIMENTAL
> + help
> + If you say yes here you get support for the Analog Devices
> + ADT7411 voltage and temperature monitoring chip.
> +
> + This driver can also be built as a module. If so, the module
> + will be called adt7411.
> +
> config SENSORS_ADT7462
> tristate "Analog Devices ADT7462"
> depends on I2C && EXPERIMENTAL
> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
> index 4bc215c..5fe67bf 100644
> --- a/drivers/hwmon/Makefile
> +++ b/drivers/hwmon/Makefile
> @@ -29,6 +29,7 @@ obj-$(CONFIG_SENSORS_ADM1029) += adm1029.o
> obj-$(CONFIG_SENSORS_ADM1031) += adm1031.o
> obj-$(CONFIG_SENSORS_ADM9240) += adm9240.o
> obj-$(CONFIG_SENSORS_ADS7828) += ads7828.o
> +obj-$(CONFIG_SENSORS_ADT7411) += adt7411.o
> obj-$(CONFIG_SENSORS_ADT7462) += adt7462.o
> obj-$(CONFIG_SENSORS_ADT7470) += adt7470.o
> obj-$(CONFIG_SENSORS_ADT7473) += adt7473.o
> diff --git a/drivers/hwmon/adt7411.c b/drivers/hwmon/adt7411.c
> new file mode 100644
> index 0000000..6e16826
> --- /dev/null
> +++ b/drivers/hwmon/adt7411.c
> @@ -0,0 +1,361 @@
> +/*
> + * Driver for the ADT7411 (I2C/SPI 8 channel 10 bit ADC & temperature-sensor)
> + *
> + * Copyright (C) 2008, 2010 Pengutronix
> + *
> + * 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
> + * published by the Free Software Foundation.
> + *
> + * TODO: SPI, support for external temperature sensor
> + * use power-down mode for suspend?, interrupt handling?
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/err.h>
> +#include <linux/delay.h>
> +#include <linux/mutex.h>
> +#include <linux/jiffies.h>
> +#include <linux/i2c.h>
> +#include <linux/hwmon.h>
> +#include <linux/hwmon-sysfs.h>
> +
> +#define ADT7411_REG_INT_TEMP_VDD_LSB 0x03
> +#define ADT7411_REG_EXT_TEMP_AIN14_LSB 0x04
> +#define ADT7411_REG_VDD_MSB 0x06
> +#define ADT7411_REG_INT_TEMP_MSB 0x07
> +#define ADT7411_REG_EXT_TEMP_AIN1_MSB 0x08
> +
> +#define ADT7411_REG_CFG1 0x18
> +#define ADT7411_CFG1_START_MONITOR (1 << 0)
> +
> +#define ADT7411_REG_CFG2 0x19
> +#define ADT7411_CFG2_DISABLE_AVG (1 << 5)
> +
> +#define ADT7411_REG_CFG3 0x1a
> +#define ADT7411_CFG3_ADC_CLK_225 (1 << 0)
> +#define ADT7411_CFG3_REF_VDD (1 << 4)
> +
> +#define ADT7411_REG_DEVICE_ID 0x4d
> +#define ADT7411_REG_MANUFACTURER_ID 0x4e
> +
> +#define ADT7411_DEVICE_ID 0x2
> +#define ADT7411_MANUFACTURER_ID 0x41
> +
> +static const unsigned short normal_i2c[] = { 0x48, 0x4a, 0x4b, I2C_CLIENT_END };
> +
> +struct adt7411_data {
> + struct mutex device_lock; /* for "atomic" device accesses */
> + unsigned long next_update;
> + int vdd_cached;
> + bool ref_is_vdd;
> + struct device *hwmon_dev;
> +};
> +
> +/*
> + * When reading a register containing (up to 4) lsb, all associated
> + * msb-registers get locked by the hardware. After _one_ of those msb is read,
> + * _all_ are unlocked. In order to use this locking correctly, reading lsb/msb
> + * is protected here with a mutex, too.
> + */
> +static int adt7411_read_10_bit(struct i2c_client *client, u8 lsb_reg,
> + u8 msb_reg, u8 lsb_shift)
> +{
> + struct adt7411_data *data = i2c_get_clientdata(client);
> + int val, tmp;
> +
> + mutex_lock(&data->device_lock);
> +
> + val = i2c_smbus_read_byte_data(client, lsb_reg);
> + if (val < 0)
> + goto exit_unlock;
> +
> + tmp = (val >> lsb_shift) & 3;
> + val = i2c_smbus_read_byte_data(client, msb_reg);
> +
> + if (val >= 0)
> + val = (val << 2) | tmp;
> +
> + exit_unlock:
> + mutex_unlock(&data->device_lock);
> +
> + return val;
> +}
> +
> +static int adt7411_modify_bit(struct i2c_client *client, u8 reg, u8 bit,
> + bool flag)
> +{
> + struct adt7411_data *data = i2c_get_clientdata(client);
> + int ret, val;
> +
> + mutex_lock(&data->device_lock);
> +
> + ret = i2c_smbus_read_byte_data(client, reg);
> + if (ret < 0)
> + goto exit_unlock;
> +
> + if (flag)
> + val = ret | bit;
> + else
> + val = ret & ~bit;
> +
> + ret = i2c_smbus_write_byte_data(client, reg, val);
> +
> + exit_unlock:
> + mutex_unlock(&data->device_lock);
> + return ret;
> +}
> +
> +static int adt7411_read_vdd(struct i2c_client *client)
> +{
> + struct adt7411_data *data = i2c_get_clientdata(client);
> + int val = adt7411_read_10_bit(client, ADT7411_REG_INT_TEMP_VDD_LSB,
> + ADT7411_REG_VDD_MSB, 2);
> +
> + if (val < 0)
> + return val;
> +
> + data->vdd_cached = val;
> + data->next_update = jiffies + HZ;
> + return val;
> +}
> +
> +static ssize_t adt7411_show_vdd(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct i2c_client *client = to_i2c_client(dev);
> + int ret = adt7411_read_vdd(client);
> +
> + return ret < 0 ? ret : sprintf(buf, "%u\n", ret * 7000 / 1024);
> +}
> +
> +static ssize_t adt7411_show_temp(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct i2c_client *client = to_i2c_client(dev);
> + int val = adt7411_read_10_bit(client, ADT7411_REG_INT_TEMP_VDD_LSB,
> + ADT7411_REG_INT_TEMP_MSB, 0);
> +
> + if (val < 0)
> + return val;
> +
> + val = val & 0x200 ? val - 0x400 : val; /* 10 bit signed */
> +
> + return sprintf(buf, "%d\n", val * 250);
> +}
> +
> +static ssize_t adt7411_show_input(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + int nr = to_sensor_dev_attr(attr)->index;
> + struct i2c_client *client = to_i2c_client(dev);
> + struct adt7411_data *data = i2c_get_clientdata(client);
> + int v_ref, val;
> + u8 lsb_reg, lsb_shift;
> +
> + if (time_after_eq(jiffies, data->next_update)) {
> + val = i2c_smbus_read_byte_data(client, ADT7411_REG_CFG3);
> + if (val < 0)
> + return val;
> + data->ref_is_vdd = val & ADT7411_CFG3_REF_VDD;
> +
> + val = adt7411_read_vdd(client);
> + if (val < 0)
> + return val;
> + }
It's a little odd that you still read vdd even when it is not used as
the reference. OTOH, if you do not, then data->next_update is not
updated, which means that you'll read ADT7411_REG_CFG3 for every
voltage input, which is worse performance-wise when reading all voltage
inputs at once (as "sensors" does).
There is a logic flaw in your code. If vdd (in0_input) is read from
user-space before any other voltage input (and this is exactly what
"sensors" will do), adt7411_read_vdd() will be called first, updating
data->next_update. Then adt7411_show_input() will be called, but the
above block will be skipped, because data->next_update has just been
set to 1 second in the future. As a result, you'll use data->ref_is_vdd
below while it has never been set. The compiler would have warned you
if ref_is_vdd was a local variable rather than a struct adt7411_data
member.
I don't quite get why adt7411_read_vdd() is responsible for updating
data->next_update, while it doesn't make use of its value.
data->next_update is only used by adt7411_show_input() so it would make
more sense to set it there too. It would be more flexible, as you could
decide that the cache (the lifetime of which is controlled by
data->next_update) includes both the value of vdd and the value of
ref_is_vdd. This would avoid reading vdd when you don't need it, and
guarantee that you never use uninitialized values.
> +
> + lsb_reg = ADT7411_REG_EXT_TEMP_AIN14_LSB + (nr >> 2);
> + lsb_shift = 2 * (nr & 0x03);
> + val = adt7411_read_10_bit(client, lsb_reg,
> + ADT7411_REG_EXT_TEMP_AIN1_MSB + nr, lsb_shift);
> + if (val < 0)
> + return val;
> +
> + if (data->ref_is_vdd)
> + v_ref = data->vdd_cached * 7000 / 1024;
> + else
> + v_ref = 2250;
> +
> + return sprintf(buf, "%u\n", val * v_ref / 1024);
> +}
> +
> +static ssize_t adt7411_show_bit(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct sensor_device_attribute_2 *attr2 = to_sensor_dev_attr_2(attr);
> + struct i2c_client *client = to_i2c_client(dev);
> + int ret = i2c_smbus_read_byte_data(client, attr2->index);
> +
> + return ret < 0 ? ret : sprintf(buf, "%u\n", !!(ret & attr2->nr));
> +}
> +
> +static ssize_t adt7411_set_bit(struct device *dev, struct device_attribute *attr,
> + const char *buf, size_t count)
> +{
> + struct sensor_device_attribute_2 *s_attr2 = to_sensor_dev_attr_2(attr);
> + struct i2c_client *client = to_i2c_client(dev);
> + int ret;
> + unsigned long flag;
> +
> + ret = strict_strtoul(buf, 0, &flag);
> + if (ret || flag > 1)
> + return -EINVAL;
> +
> + ret = adt7411_modify_bit(client, s_attr2->index, s_attr2->nr, flag);
> + return ret < 0 ? ret : count;
> +}
Calling the above function should invalidate the cache. At least
changing adc_ref_vdd makes the cached value data->adc_ref_vdd wrong,
and presumably the other settings may also affect the value of
data->vdd_cached. As I don't expect the user to change the settings
frequently, there's probably no point in trying to be smart.
> +
> +#define ADT7411_BIT_ATTR(__name, __reg, __bit) \
> + SENSOR_DEVICE_ATTR_2(__name, S_IRUGO | S_IWUSR, adt7411_show_bit, \
> + adt7411_set_bit, __bit, __reg)
> +
> +static DEVICE_ATTR(temp1_input, S_IRUGO, adt7411_show_temp, NULL);
> +static DEVICE_ATTR(in0_input, S_IRUGO, adt7411_show_vdd, NULL);
> +static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, adt7411_show_input, NULL, 0);
> +static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, adt7411_show_input, NULL, 1);
> +static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, adt7411_show_input, NULL, 2);
> +static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, adt7411_show_input, NULL, 3);
> +static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, adt7411_show_input, NULL, 4);
> +static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, adt7411_show_input, NULL, 5);
> +static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, adt7411_show_input, NULL, 6);
> +static SENSOR_DEVICE_ATTR(in8_input, S_IRUGO, adt7411_show_input, NULL, 7);
> +static ADT7411_BIT_ATTR(no_average, ADT7411_REG_CFG2, ADT7411_CFG2_DISABLE_AVG);
> +static ADT7411_BIT_ATTR(fast_sampling, ADT7411_REG_CFG3, ADT7411_CFG3_ADC_CLK_225);
> +static ADT7411_BIT_ATTR(adc_ref_vdd, ADT7411_REG_CFG3, ADT7411_CFG3_REF_VDD);
> +
> +static struct attribute *adt7411_attrs[] = {
> + &dev_attr_temp1_input.attr,
> + &dev_attr_in0_input.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,
> + &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,
> + &sensor_dev_attr_in8_input.dev_attr.attr,
> + &sensor_dev_attr_no_average.dev_attr.attr,
> + &sensor_dev_attr_fast_sampling.dev_attr.attr,
> + &sensor_dev_attr_adc_ref_vdd.dev_attr.attr,
> + NULL
> +};
> +
> +static const struct attribute_group adt7411_attr_grp = {
> + .attrs = adt7411_attrs,
> +};
> +
> +static int adt7411_detect(struct i2c_client *client, struct i2c_board_info *info)
> +{
> + int val;
> +
> + if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
> + return -ENODEV;
> +
> + val = i2c_smbus_read_byte_data(client, ADT7411_REG_MANUFACTURER_ID);
> + if (val < 0 || val != ADT7411_MANUFACTURER_ID) {
> + dev_err(&client->dev, "Wrong manufacturer ID. Got %d, "
> + "expected %d\n", val, ADT7411_MANUFACTURER_ID);
> + return -ENODEV;
> + }
> +
> + val = i2c_smbus_read_byte_data(client, ADT7411_REG_DEVICE_ID);
> + if (val < 0 || val != ADT7411_DEVICE_ID) {
> + dev_err(&client->dev, "Wrong device ID. Got %d, "
> + "expected %d\n", val, ADT7411_DEVICE_ID);
> + return -ENODEV;
> + }
These should be debug messages, not error ones. There's nothing wrong in
loading the adt7411 driver on a system with an ADT7411 device plus
another device.
> +
> + strlcpy(info->type, "adt7411", I2C_NAME_SIZE);
> +
> + return 0;
> +}
> +
> +static int __devinit adt7411_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + struct adt7411_data *data;
> + int ret;
> +
> + data = kzalloc(sizeof(*data), GFP_KERNEL);
> + if (!data)
> + return -ENOMEM;
> +
> + i2c_set_clientdata(client, data);
> + mutex_init(&data->device_lock);
> +
> + ret = adt7411_modify_bit(client, ADT7411_REG_CFG1,
> + ADT7411_CFG1_START_MONITOR, 1);
> + if (ret < 0)
> + goto exit_free;
> +
> + /* force update on first occasion */
> + data->next_update = jiffies;
> +
> + ret = sysfs_create_group(&client->dev.kobj, &adt7411_attr_grp);
> + if (ret)
> + goto exit_free;
> +
> + data->hwmon_dev = hwmon_device_register(&client->dev);
> + if (IS_ERR(data->hwmon_dev)) {
> + ret = PTR_ERR(data->hwmon_dev);
> + goto exit_remove;
> + }
> +
> + dev_info(&client->dev, "successfully registered\n");
> +
> + return 0;
> +
> + exit_remove:
> + sysfs_remove_group(&client->dev.kobj, &adt7411_attr_grp);
> + exit_free:
> + i2c_set_clientdata(client, NULL);
> + kfree(data);
> + return ret;
> +}
> +
> +static int __devexit adt7411_remove(struct i2c_client *client)
> +{
> + struct adt7411_data *data = i2c_get_clientdata(client);
> +
> + hwmon_device_unregister(data->hwmon_dev);
> + sysfs_remove_group(&client->dev.kobj, &adt7411_attr_grp);
> + i2c_set_clientdata(client, NULL);
> + kfree(data);
> + return 0;
> +}
> +
> +static const struct i2c_device_id adt7411_id[] = {
> + { "adt7411", 0 },
> + { }
> +};
> +
> +static struct i2c_driver adt7411_driver = {
> + .driver = {
> + .name = "adt7411",
> + },
> + .probe = adt7411_probe,
> + .remove = __devexit_p(adt7411_remove),
> + .id_table = adt7411_id,
> + .detect = adt7411_detect,
> + .address_list = normal_i2c,
> + .class = I2C_CLASS_HWMON,
> +};
> +
> +static int __init sensors_adt7411_init(void)
> +{
> + return i2c_add_driver(&adt7411_driver);
> +}
> +module_init(sensors_adt7411_init)
> +
> +static void __exit sensors_adt7411_exit(void)
> +{
> + i2c_del_driver(&adt7411_driver);
> +}
> +module_exit(sensors_adt7411_exit)
> +
> +MODULE_AUTHOR("Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> and "
> + "Wolfram Sang <w.sang@xxxxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("ADT7411 driver");
> +MODULE_LICENSE("GPL v2");
The rest looks fine to me, thanks.
--
Jean Delvare
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