From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
To: Kent Gibson <warthog618@gmail.com>
Cc: linux-gpio <linux-gpio@vger.kernel.org>
Subject: Re: [libgpiod][PATCH v3 07/14] core: add support for SET_CONFIG
Date: Thu, 28 Nov 2019 11:29:14 +0100 [thread overview]
Message-ID: <CAMpxmJUzVAeVysoig4O0rczTFbeOz4xCmSNm8OYVogwXuOmj+g@mail.gmail.com> (raw)
In-Reply-To: <20191125143157.26154-8-warthog618@gmail.com>
pon., 25 lis 2019 o 15:32 Kent Gibson <warthog618@gmail.com> napisał(a):
>
> Extend the libgpiod API to support the setting line configuration using the
> GPIO GPIOHANDLE_SET_CONFIG_IOCTL uAPI ioctl.
>
> The core change is the addition of gpiod_line_set_config, which provides a
> low level wrapper around the ioctl.
>
> Additionally, higher level helper functions, gpiod_line_set_flags,
> gpiod_line_set_direction_input, and gpiod_line_set_direction_output provide
> slightly simplified APIs for common use cases.
>
> Bulk forms of all functions are also provided.
>
> Signed-off-by: Kent Gibson <warthog618@gmail.com>
> ---
> include/gpiod.h | 123 +++++++++++++++++++++++++++++++
> lib/core.c | 187 +++++++++++++++++++++++++++++++++++++++++++++++-
> 2 files changed, 307 insertions(+), 3 deletions(-)
>
> diff --git a/include/gpiod.h b/include/gpiod.h
> index 86c3ea9..185e2f4 100644
> --- a/include/gpiod.h
> +++ b/include/gpiod.h
> @@ -1246,6 +1246,15 @@ void gpiod_line_release_bulk(struct gpiod_line_bulk *bulk) GPIOD_API;
> */
> bool gpiod_line_is_requested(struct gpiod_line *line) GPIOD_API;
>
> +/**
> + * @brief Check if the calling user has ownership of this line for values,
> + * not events.
For consistency: please align this with the beginning of the
description above...
> + * @param line GPIO line object.
> + * @return True if given line was requested for reading/setting values,
> + * false otherwise.
> + */
> +bool gpiod_line_is_requested_values(struct gpiod_line *line) GPIOD_API;
... but also: why do we need to export this anyway?
> +
> /**
> * @brief Check if the calling user has neither requested ownership of this
> * line nor configured any event notifications.
> @@ -1296,6 +1305,7 @@ int gpiod_line_set_value(struct gpiod_line *line, int value) GPIOD_API;
> * @brief Set the values of a set of GPIO lines.
> * @param bulk Set of GPIO lines to reserve.
> * @param values An array holding line_bulk->num_lines new values for lines.
> + * A NULL pointer is interpreted as a logical low for all lines.
This looks like part of a different commit.
> * @return 0 is the operation succeeds. In case of an error this routine
> * returns -1 and sets the last error number.
> *
> @@ -1305,6 +1315,119 @@ int gpiod_line_set_value(struct gpiod_line *line, int value) GPIOD_API;
> int gpiod_line_set_value_bulk(struct gpiod_line_bulk *bulk,
> const int *values) GPIOD_API;
>
> +/**
> + * @}
> + *
> + * @defgroup __line_config__ Setting line configuration
> + * @{
> + */
> +
> +/**
> + * @brief Update the configuration of a single GPIO line.
> + * @param line GPIO line object.
> + * @param direction Updated direction which may be one of
> + * GPIOD_LINE_REQUEST_DIRECTION_AS_IS,
> + * GPIOD_LINE_REQUEST_DIRECTION_INPUT, or
> + * GPIOD_LINE_REQUEST_DIRECTION_OUTPUT.
> + * @param flags Replacement flags.
> + * @param value The new output value for the line when direction is
> + * GPIOD_LINE_REQUEST_DIRECTION_OUTPUT.
> + * @return 0 is the operation succeeds. In case of an error this routine
> + * returns -1 and sets the last error number.
> + */
> +int gpiod_line_set_config(struct gpiod_line *line, int direction,
> + int flags, int value) GPIOD_API;
> +
> +/**
> + * @brief Update the configuration of a set of GPIO lines.
> + * @param bulk Set of GPIO lines.
> + * @param direction Updated direction which may be one of
> + * GPIOD_LINE_REQUEST_DIRECTION_AS_IS,
> + * GPIOD_LINE_REQUEST_DIRECTION_INPUT, or
> + * GPIOD_LINE_REQUEST_DIRECTION_OUTPUT.
> + * @param flags Replacement flags.
> + * @param values An array holding line_bulk->num_lines new logical values
> + * for lines when direction is
> + * GPIOD_LINE_REQUEST_DIRECTION_OUTPUT.
> + * A NULL pointer is interpreted as a logical low for all lines.
> + * @return 0 is the operation succeeds. In case of an error this routine
> + * returns -1 and sets the last error number.
> + *
> + * If the lines were not previously requested together, the behavior is
> + * undefined.
> + */
> +int gpiod_line_set_config_bulk(struct gpiod_line_bulk *bulk,
> + int direction, int flags,
> + const int *values) GPIOD_API;
> +
> +
> +/**
> + * @brief Update the configuration flags of a single GPIO line.
> + * @param line GPIO line object.
> + * @param flags Replacement flags.
> + * @return 0 is the operation succeeds. In case of an error this routine
> + * returns -1 and sets the last error number.
> + */
> +int gpiod_line_set_flags(struct gpiod_line *line, int flags) GPIOD_API;
> +
> +/**
> + * @brief Update the configuration flags of a set of GPIO lines.
> + * @param bulk Set of GPIO lines.
> + * @param flags Replacement flags.
> + * @return 0 is the operation succeeds. In case of an error this routine
> + * returns -1 and sets the last error number.
> + *
> + * If the lines were not previously requested together, the behavior is
> + * undefined.
> + */
> +int gpiod_line_set_flags_bulk(struct gpiod_line_bulk *bulk,
> + int flags) GPIOD_API;
> +
> +/**
> + * @brief Set the direction of a single GPIO line to input.
> + * @param line GPIO line object.
> + * @return 0 is the operation succeeds. In case of an error this routine
> + * returns -1 and sets the last error number.
> + */
> +int gpiod_line_set_direction_input(struct gpiod_line *line) GPIOD_API;
> +
> +/**
> + * @brief Set the direction of a set of GPIO lines to input.
> + * @param bulk Set of GPIO lines.
> + * @return 0 is the operation succeeds. In case of an error this routine
> + * returns -1 and sets the last error number.
> + *
> + * If the lines were not previously requested together, the behavior is
> + * undefined.
> + */
> +int gpiod_line_set_direction_input_bulk(struct gpiod_line_bulk *bulk
> + ) GPIOD_API;
> +
> +/**
> + * @brief Set the direction of a single GPIO line to output.
> + * @param line GPIO line object.
> + * @param value The logical value output on the line.
> + * @return 0 is the operation succeeds. In case of an error this routine
> + * returns -1 and sets the last error number.
> + */
> +int gpiod_line_set_direction_output(struct gpiod_line *line,
> + int value) GPIOD_API;
> +
> +/**
> + * @brief Set the direction of a set of GPIO lines to output.
> + * @param bulk Set of GPIO lines.
> + * @param values An array holding line_bulk->num_lines new logical values
> + * for lines. A NULL pointer is interpreted as a logical low
> + * for all lines.
> + * @return 0 is the operation succeeds. In case of an error this routine
> + * returns -1 and sets the last error number.
> + *
> + * If the lines were not previously requested together, the behavior is
> + * undefined.
> + */
> +int gpiod_line_set_direction_output_bulk(struct gpiod_line_bulk *bulk,
> + const int *values) GPIOD_API;
> +
> /**
> * @}
> *
> diff --git a/lib/core.c b/lib/core.c
> index 0465de9..71bb4fb 100644
> --- a/lib/core.c
> +++ b/lib/core.c
> @@ -34,10 +34,26 @@ struct line_fd_handle {
>
> struct gpiod_line {
> unsigned int offset;
> +
> + /* The GPIOD_LINE_DIRECTION */
> int direction;
> +
> + /* The GPIOD_LINE_ACTIVE_STATE */
> int active_state;
> +
> + /* The logical value last written to the line. */
> + int output_value;
> +
> + /* The GPIOLINE_FLAGs returned by GPIO_GET_LINEINFO_IOCTL */
> __u32 info_flags;
>
> + /* The GPIOD_LINE_REQUEST_FLAGs provided to request the line. */
> + __u32 req_flags;
> +
> + /*
> + * Indicator of LINE_FREE, LINE_REQUESTED_VALUES or
> + * LINE_REQUESTED_EVENTS
> + */
> int state;
Please include the mention on documenting this in the commit message.
Otherwise it looks like it should be part of a different commit.
>
> struct gpiod_chip *chip;
> @@ -445,6 +461,20 @@ static bool line_bulk_all_requested(struct gpiod_line_bulk *bulk)
> return true;
> }
>
> +static bool line_bulk_all_requested_values(struct gpiod_line_bulk *bulk)
> +{
> + struct gpiod_line *line, **lineptr;
> +
> + gpiod_line_bulk_foreach_line(bulk, line, lineptr) {
> + if (!gpiod_line_is_requested_values(line)) {
> + errno = EPERM;
> + return false;
> + }
> + }
> +
> + return true;
> +}
> +
> static bool line_bulk_all_free(struct gpiod_line_bulk *bulk)
> {
> struct gpiod_line *line, **lineptr;
> @@ -459,6 +489,27 @@ static bool line_bulk_all_free(struct gpiod_line_bulk *bulk)
> return true;
> }
>
> +static bool line_request_direction_is_valid(int direction)
> +{
> + if ((direction == GPIOD_LINE_REQUEST_DIRECTION_AS_IS) ||
> + (direction == GPIOD_LINE_REQUEST_DIRECTION_INPUT) ||
> + (direction == GPIOD_LINE_REQUEST_DIRECTION_OUTPUT))
> + return true;
> +
> + errno = EINVAL;
> + return false;
> +}
Same here: please be a bit more elaborate in the commit message. Say
something like: "while at it: restructure the code by doing this and
that".
> +
> +static __u32 line_request_direction_to_gpio_handleflag(int direction)
> +{
> + if (direction == GPIOD_LINE_REQUEST_DIRECTION_INPUT)
> + return GPIOHANDLE_REQUEST_INPUT;
> + if (direction == GPIOD_LINE_REQUEST_DIRECTION_OUTPUT)
> + return GPIOHANDLE_REQUEST_OUTPUT;
> +
> + return 0;
> +}
> +
> static __u32 line_request_flag_to_gpio_handleflag(int flags)
> {
> int hflags = 0;
> @@ -483,7 +534,7 @@ static int line_request_values(struct gpiod_line_bulk *bulk,
> const struct gpiod_line_request_config *config,
> const int *default_vals)
> {
> - struct gpiod_line *line, **lineptr;
> + struct gpiod_line *line;
> struct line_fd_handle *line_fd;
> struct gpiohandle_request req;
> unsigned int i;
> @@ -512,7 +563,6 @@ static int line_request_values(struct gpiod_line_bulk *bulk,
> else if (config->request_type == GPIOD_LINE_REQUEST_DIRECTION_OUTPUT)
> req.flags |= GPIOHANDLE_REQUEST_OUTPUT;
>
> -
Fixing stray newlines etc should be in separate commits too IMO but
let's let is slip here, this is already a big patch anyway.
> gpiod_line_bulk_foreach_line_off(bulk, line, i) {
> req.lineoffsets[i] = gpiod_line_offset(line);
> if (config->request_type ==
> @@ -536,8 +586,12 @@ static int line_request_values(struct gpiod_line_bulk *bulk,
> if (!line_fd)
> return -1;
>
> - gpiod_line_bulk_foreach_line(bulk, line, lineptr) {
> + gpiod_line_bulk_foreach_line_off(bulk, line, i) {
> line->state = LINE_REQUESTED_VALUES;
> + line->req_flags = config->flags;
> + if (config->request_type ==
> + GPIOD_LINE_REQUEST_DIRECTION_OUTPUT)
Add another tab here because otherwise there's no indentation
difference between this line and the line below.
> + line->output_value = req.default_values[i];
> line_set_fd(line, line_fd);
>
> rv = gpiod_line_update(line);
> @@ -583,6 +637,7 @@ static int line_request_event_single(struct gpiod_line *line,
> return -1;
>
> line->state = LINE_REQUESTED_EVENTS;
> + line->req_flags = config->flags;
> line_set_fd(line, line_fd);
>
> rv = gpiod_line_update(line);
> @@ -686,6 +741,11 @@ bool gpiod_line_is_requested(struct gpiod_line *line)
> line->state == LINE_REQUESTED_EVENTS);
> }
>
> +bool gpiod_line_is_requested_values(struct gpiod_line *line)
> +{
> + return (line->state == LINE_REQUESTED_VALUES);
> +}
> +
> bool gpiod_line_is_free(struct gpiod_line *line)
> {
> return line->state == LINE_FREE;
> @@ -766,9 +826,130 @@ int gpiod_line_set_value_bulk(struct gpiod_line_bulk *bulk, const int *values)
> if (rv < 0)
> return -1;
>
> + gpiod_line_bulk_foreach_line_off(bulk, line, i)
> + line->output_value = data.values[i];
> +
> return 0;
> }
>
> +int gpiod_line_set_config(struct gpiod_line *line, int direction,
> + int flags, int value)
> +{
> + struct gpiod_line_bulk bulk;
> +
> + gpiod_line_bulk_init(&bulk);
> + gpiod_line_bulk_add(&bulk, line);
> +
> + return gpiod_line_set_config_bulk(&bulk, direction, flags, &value);
> +}
> +
> +int gpiod_line_set_config_bulk(struct gpiod_line_bulk *bulk,
> + int direction, int flags,
> + const int *values)
> +{
> + struct gpiohandle_config hcfg;
> + struct gpiod_line *line;
> + unsigned int i;
> + int rv, fd;
> +
> + if (!line_bulk_same_chip(bulk) ||
> + !line_bulk_all_requested_values(bulk))
> + return -1;
> +
> + if (!line_request_direction_is_valid(direction))
> + return -1;
> +
> + memset(&hcfg, 0, sizeof(hcfg));
> +
> + hcfg.flags = line_request_flag_to_gpio_handleflag(flags);
> + hcfg.flags |= line_request_direction_to_gpio_handleflag(direction);
> + if (direction == GPIOD_LINE_REQUEST_DIRECTION_OUTPUT && values) {
> + for (i = 0; i < gpiod_line_bulk_num_lines(bulk); i++)
> + hcfg.default_values[i] = (uint8_t)!!values[i];
> + }
> +
> + line = gpiod_line_bulk_get_line(bulk, 0);
> + fd = line_get_fd(line);
> +
> + rv = ioctl(fd, GPIOHANDLE_SET_CONFIG_IOCTL, &hcfg);
> + if (rv < 0)
> + return -1;
> +
> + gpiod_line_bulk_foreach_line_off(bulk, line, i) {
> + line->req_flags = flags;
> + if (direction == GPIOD_LINE_REQUEST_DIRECTION_OUTPUT)
> + line->output_value = hcfg.default_values[i];
Please add a newline here.
> + rv = gpiod_line_update(line);
> + if (rv < 0)
> + return rv;
> + }
> + return 0;
> +}
> +
> +int gpiod_line_set_flags(struct gpiod_line *line, int flags)
> +{
> + struct gpiod_line_bulk bulk;
> +
> + gpiod_line_bulk_init(&bulk);
> + gpiod_line_bulk_add(&bulk, line);
> +
> + return gpiod_line_set_flags_bulk(&bulk, flags);
> +}
> +
> +int gpiod_line_set_flags_bulk(struct gpiod_line_bulk *bulk, int flags)
> +{
> + struct gpiod_line *line;
> + int values[GPIOD_LINE_BULK_MAX_LINES];
> + unsigned int i;
> + int direction;
> +
> + line = gpiod_line_bulk_get_line(bulk, 0);
> + if (line->direction == GPIOD_LINE_DIRECTION_OUTPUT) {
> + gpiod_line_bulk_foreach_line_off(bulk, line, i) {
> + values[i] = line->output_value;
> + }
No need for brackets here.
> + direction = GPIOD_LINE_REQUEST_DIRECTION_OUTPUT;
> + } else {
> + direction = GPIOD_LINE_REQUEST_DIRECTION_INPUT;
> + }
> +
> + return gpiod_line_set_config_bulk(bulk, direction,
> + flags, values);
> +}
> +
> +int gpiod_line_set_direction_input(struct gpiod_line *line)
> +{
> + return gpiod_line_set_config(line, GPIOD_LINE_REQUEST_DIRECTION_INPUT,
> + line->req_flags, 0);
> +}
> +
> +int gpiod_line_set_direction_input_bulk(struct gpiod_line_bulk *bulk)
> +{
> + struct gpiod_line *line;
> +
> + line = gpiod_line_bulk_get_line(bulk, 0);
> + return gpiod_line_set_config_bulk(bulk,
> + GPIOD_LINE_REQUEST_DIRECTION_INPUT,
> + line->req_flags, NULL);
> +}
> +
> +int gpiod_line_set_direction_output(struct gpiod_line *line, int value)
> +{
> + return gpiod_line_set_config(line, GPIOD_LINE_REQUEST_DIRECTION_OUTPUT,
> + line->req_flags, value);
> +}
> +
> +int gpiod_line_set_direction_output_bulk(struct gpiod_line_bulk *bulk,
> + const int *values)
> +{
> + struct gpiod_line *line;
> +
> + line = gpiod_line_bulk_get_line(bulk, 0);
> + return gpiod_line_set_config_bulk(bulk,
> + GPIOD_LINE_REQUEST_DIRECTION_OUTPUT,
> + line->req_flags, values);
> +}
> +
> int gpiod_line_event_wait(struct gpiod_line *line,
> const struct timespec *timeout)
> {
> --
> 2.24.0
>
next prev parent reply other threads:[~2019-11-28 10:29 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-25 14:31 [libgpiod][PATCH v3 00/14] Add support for bias flags and SET_CONFIG Kent Gibson
2019-11-25 14:31 ` [libgpiod][PATCH v3 01/14] core: add support for bias flags Kent Gibson
2019-11-25 14:31 ` [libgpiod][PATCH v3 02/14] tests: add tests " Kent Gibson
2019-11-28 10:28 ` Bartosz Golaszewski
2019-11-25 14:31 ` [libgpiod][PATCH v3 03/14] bindings: cxx: add support " Kent Gibson
2019-11-28 10:29 ` Bartosz Golaszewski
2019-11-25 14:31 ` [libgpiod][PATCH v3 04/14] bindings: cxx: tests: add tests " Kent Gibson
2019-11-25 14:31 ` [libgpiod][PATCH v3 05/14] bindings: python: add support " Kent Gibson
2019-11-25 14:31 ` [libgpiod][PATCH v3 06/14] bindings: python: tests: add tests " Kent Gibson
2019-11-25 14:31 ` [libgpiod][PATCH v3 07/14] core: add support for SET_CONFIG Kent Gibson
2019-11-28 10:29 ` Bartosz Golaszewski [this message]
2019-11-25 14:31 ` [libgpiod][PATCH v3 08/14] tests: add tests " Kent Gibson
2019-11-25 14:31 ` [libgpiod][PATCH v3 09/14] bindings: cxx: add support " Kent Gibson
2019-11-28 10:29 ` Bartosz Golaszewski
2019-11-25 14:31 ` [libgpiod][PATCH v3 10/14] bindings: cxx: tests: add tests for SET_CONFIG methods Kent Gibson
2019-11-25 14:31 ` [libgpiod][PATCH v3 11/14] bindings: python: add support for SET_CONFIG Kent Gibson
2019-11-28 10:29 ` Bartosz Golaszewski
2019-11-25 14:31 ` [libgpiod][PATCH v3 12/14] bindings: python: tests: add tests for SET_CONFIG methods Kent Gibson
2019-11-25 14:31 ` [libgpiod][PATCH v3 13/14] tools: add support for bias flags Kent Gibson
2019-11-28 10:29 ` Bartosz Golaszewski
2019-11-25 14:31 ` [libgpiod][PATCH v3 14/14] tools: add tests for bias and drive flags Kent Gibson
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