From 8cb3403633146afe1ba81f79224679f5df2940d4 Mon Sep 17 00:00:00 2001 From: Andrea Merello Date: Wed, 20 Nov 2019 15:47:51 +0100 Subject: [PATCH] iio: core: add char type for sysfs attributes This patch introduces IIO_VAL_CHAR type for standard IIO attributes to allow for attributes that needs to be represented by character rather than a number. This is preparatory for introducing a new attribute whose purpose is to describe thermocouple type, that can be i.e. "J", "K", etc.. The char-type value is stored in the first "value" integer that is passed to the .[read/write]_raw() callbacks. Note that in order to make it possible for the IIO core to correctly parse this type (actually, to avoid integer parsing), it became mandatory for any driver that wish to use IIO_VAL_CHAR on a writable attribute to implement .write_raw_get_fmt(). Cc: Hartmut Knaack Cc: Lars-Peter Clausen Cc: Peter Meerwald-Stadler Cc: Colin Ian King Cc: Patrick Havelange Cc: Matt Weber Cc: Matt Ranostay Cc: Chuhong Yuan Cc: Daniel Gomez Cc: linux-iio@vger.kernel.org Signed-off-by: Andrea Merello Signed-off-by: Jonathan Cameron --- drivers/iio/industrialio-core.c | 22 ++++++++++++++++++---- include/linux/iio/types.h | 1 + 2 files changed, 19 insertions(+), 4 deletions(-) diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c index f72c2dc5f703f..958b5c48a86fa 100644 --- a/drivers/iio/industrialio-core.c +++ b/drivers/iio/industrialio-core.c @@ -596,6 +596,8 @@ static ssize_t __iio_format_value(char *buf, size_t len, unsigned int type, } return l; } + case IIO_VAL_CHAR: + return snprintf(buf, len, "%c", (char)vals[0]); default: return 0; } @@ -837,7 +839,8 @@ static ssize_t iio_write_channel_info(struct device *dev, struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); int ret, fract_mult = 100000; - int integer, fract; + int integer, fract = 0; + bool is_char = false; /* Assumes decimal - precision based on number of digits */ if (!indio_dev->info->write_raw) @@ -855,13 +858,24 @@ static ssize_t iio_write_channel_info(struct device *dev, case IIO_VAL_INT_PLUS_NANO: fract_mult = 100000000; break; + case IIO_VAL_CHAR: + is_char = true; + break; default: return -EINVAL; } - ret = iio_str_to_fixpoint(buf, fract_mult, &integer, &fract); - if (ret) - return ret; + if (is_char) { + char ch; + + if (sscanf(buf, "%c", &ch) != 1) + return -EINVAL; + integer = ch; + } else { + ret = iio_str_to_fixpoint(buf, fract_mult, &integer, &fract); + if (ret) + return ret; + } ret = indio_dev->info->write_raw(indio_dev, this_attr->c, integer, fract, this_attr->address); diff --git a/include/linux/iio/types.h b/include/linux/iio/types.h index fa824e160f35b..8e0026da38c96 100644 --- a/include/linux/iio/types.h +++ b/include/linux/iio/types.h @@ -25,6 +25,7 @@ enum iio_event_info { #define IIO_VAL_INT_MULTIPLE 5 #define IIO_VAL_FRACTIONAL 10 #define IIO_VAL_FRACTIONAL_LOG2 11 +#define IIO_VAL_CHAR 12 enum iio_available_type { IIO_AVAIL_LIST, -- 2.30.2