Re: [PATCH v2 3/3] iio: humidity: si7020: added No Hold read mode

["Nicola Corna" <nicola@corna.info>]

September 20 2015 12:40 PM, "Jonathan Cameron" <jic23@kernel.org> wrote:
> On 16/09/15 14:35, Nicola Corna wrote:
> 
>> The Si7013/20/21 modules support 2 read modes:
>> * Hold mode (blocking), where the device stretches the clock until the end
>> of the measurement
>> * No Hold mode (non-blocking), where the device replies NACK for every I2C
>> call during the measurement
>> Here the No Hold mode is implemented, selectable with the blocking_io
>> variable within si7020_platform_data. The default mode is Hold, unless the
>> adapter does not support clock stretching, in which case the No Hold mode
>> is used.
>> 
>> Signed-off-by: Nicola Corna <nicola@corna.info>
> 
> Acked-by: Jonathan Cameron <jic23@kernel.org>
> 
> Wolfram, I'm guessing you will pick these up via the i2c tree when
> he is happy with them. If you want me to take the series through IIO
> let me know.
> 
> Thanks,
> 
> Jonathan
> 
Good afternoon,

can you please review these patches?
Thanks

Nicola Corna

>> ---
>> This patch depends on patch "[PATCH v4 1/2] iio: humidity: si7020: replaced
>> bitmask on humidity values with range check"
>> drivers/iio/humidity/si7020.c | 76 ++++++++++++++++++++++++++++++++----
>> include/linux/platform_data/si7020.h | 21 ++++++++++
>> 2 files changed, 90 insertions(+), 7 deletions(-)
>> create mode 100644 include/linux/platform_data/si7020.h
>> 
>> diff --git a/drivers/iio/humidity/si7020.c b/drivers/iio/humidity/si7020.c
>> index 12128d1..9cf9527 100644
>> --- a/drivers/iio/humidity/si7020.c
>> +++ b/drivers/iio/humidity/si7020.c
>> @@ -2,6 +2,7 @@
>> * si7020.c - Silicon Labs Si7013/20/21 Relative Humidity and Temp Sensors
>> * Copyright (c) 2013,2014 Uplogix, Inc.
>> * David Barksdale <dbarksdale@uplogix.com>
>> + * Copyright (c) 2015 Nicola Corna <nicola@corna.info>
>> *
>> * This program is free software; you can redistribute it and/or modify it
>> * under the terms and conditions of the GNU General Public License,
>> @@ -30,33 +31,78 @@
>> #include <linux/module.h>
>> #include <linux/slab.h>
>> #include <linux/sysfs.h>
>> +#include <linux/jiffies.h>
>> 
>> #include <linux/iio/iio.h>
>> #include <linux/iio/sysfs.h>
>> +#include <linux/platform_data/si7020.h>
>> 
>> /* Measure Relative Humidity, Hold Master Mode */
>> #define SI7020CMD_RH_HOLD 0xE5
>> +/* Measure Relative Humidity, No Hold Master Mode */
>> +#define SI7020CMD_RH_NO_HOLD 0xF5
>> /* Measure Temperature, Hold Master Mode */
>> #define SI7020CMD_TEMP_HOLD 0xE3
>> +/* Measure Temperature, No Hold Master Mode */
>> +#define SI7020CMD_TEMP_NO_HOLD 0xF3
>> /* Software Reset */
>> #define SI7020CMD_RESET 0xFE
>> +/* Relative humidity measurement timeout (us) */
>> +#define SI7020_RH_TIMEOUT 22800
>> +/* Temperature measurement timeout (us) */
>> +#define SI7020_TEMP_TIMEOUT 10800
>> +/* Minimum delay between retries (No Hold Mode) in us */
>> +#define SI7020_NOHOLD_SLEEP_MIN 2000
>> +/* Maximum delay between retries (No Hold Mode) in us */
>> +#define SI7020_NOHOLD_SLEEP_MAX 6000
>> 
>> static int si7020_read_raw(struct iio_dev *indio_dev,
>> struct iio_chan_spec const *chan, int *val,
>> int *val2, long mask)
>> {
>> struct i2c_client **client = iio_priv(indio_dev);
>> + struct si7020_platform_data *pdata;
>> int ret;
>> + bool holdmode;
>> + unsigned char buf[2];
>> + unsigned long start;
>> 
>> switch (mask) {
>> case IIO_CHAN_INFO_RAW:
>> - ret = i2c_smbus_read_word_data(*client,
>> - chan->type == IIO_TEMP ?
>> - SI7020CMD_TEMP_HOLD :
>> - SI7020CMD_RH_HOLD);
>> - if (ret < 0)
>> - return ret;
>> - *val = ret >> 2;
>> + pdata = dev_get_platdata(&(*client)->dev);
>> + if (pdata)
>> + holdmode = pdata->blocking_io;
>> + else
>> + holdmode = !i2c_check_functionality((*client)->adapter,
>> + I2C_FUNC_NO_CLK_STRETCH);
>> + if (holdmode) {
>> + ret = i2c_smbus_read_word_data(*client,
>> + chan->type == IIO_TEMP ?
>> + SI7020CMD_TEMP_HOLD :
>> + SI7020CMD_RH_HOLD);
>> + if (ret < 0)
>> + return ret;
>> + *val = ret >> 2;
>> + } else {
>> + ret = i2c_smbus_write_byte(*client,
>> + chan->type == IIO_TEMP ?
>> + SI7020CMD_TEMP_NO_HOLD :
>> + SI7020CMD_RH_NO_HOLD);
>> + if (ret < 0)
>> + return ret;
>> + start = jiffies;
>> + while ((ret = i2c_master_recv(*client, buf, 2)) < 0) {
>> + if (time_after(jiffies, start +
>> + usecs_to_jiffies(
>> + chan->type == IIO_TEMP ?
>> + SI7020_TEMP_TIMEOUT :
>> + SI7020_RH_TIMEOUT)))
>> + return ret;
>> + usleep_range(SI7020_NOHOLD_SLEEP_MIN,
>> + SI7020_NOHOLD_SLEEP_MAX);
>> + }
>> + *val = ((buf[0] << 8) | buf[1]) >> 2;
>> + }
>> /*
>> * Humidity values can slightly exceed the 0-100%RH
>> * range and should be corrected by software
>> @@ -116,6 +162,7 @@ static int si7020_probe(struct i2c_client *client,
>> {
>> struct iio_dev *indio_dev;
>> struct i2c_client **data;
>> + struct si7020_platform_data *pdata;
>> int ret;
>> 
>> if (!i2c_check_functionality(client->adapter,
>> @@ -123,6 +170,21 @@ static int si7020_probe(struct i2c_client *client,
>> I2C_FUNC_SMBUS_READ_WORD_DATA))
>> return -ENODEV;
>> 
>> + pdata = dev_get_platdata(&client->dev);
>> + if (pdata) {
>> + if (pdata->blocking_io) {
>> + if (i2c_check_functionality(client->adapter,
>> + I2C_FUNC_NO_CLK_STRETCH))
>> + return -ENODEV;
>> + } else if (!i2c_check_functionality(client->adapter,
>> + I2C_FUNC_I2C))
>> + return -ENODEV;
>> + } else
>> + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C) &&
>> + i2c_check_functionality(client->adapter,
>> + I2C_FUNC_NO_CLK_STRETCH))
>> + return -ENODEV;
>> +
>> /* Reset device, loads default settings. */
>> ret = i2c_smbus_write_byte(client, SI7020CMD_RESET);
>> if (ret < 0)
>> diff --git a/include/linux/platform_data/si7020.h b/include/linux/platform_data/si7020.h
>> new file mode 100644
>> index 0000000..8bb5848
>> --- /dev/null
>> +++ b/include/linux/platform_data/si7020.h
>> @@ -0,0 +1,21 @@
>> +/*
>> + * Copyright (C) 2015 Nicola Corna <nicola@corna.info>
>> + *
>> + * This software is licensed under the terms of the GNU General Public
>> + * License version 2, as published by the Free Software Foundation, and
>> + * may be copied, distributed, and modified under those terms.
>> + *
>> + * This program is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
>> + * GNU General Public License for more details.
>> + *
>> + */
>> +
>> +#ifndef __SI7020_H_
>> +#define __SI7020_H_
>> +
>> +struct si7020_platform_data {
>> + bool blocking_io;
>> +};
>> +#endif /* __SI7020_H_ */