From e18a2ad45caeb11226e49c25068d0f2efe2adf6c Mon Sep 17 00:00:00 2001 From: Lars-Peter Clausen Date: Tue, 13 Oct 2015 18:10:27 +0200 Subject: [PATCH] iio: Add buffer enable/disable callbacks This patch adds a enable and disable callback that is called when the buffer is enabled/disabled. This can be used by buffer implementations that need to do some setup or teardown work. E.g. a DMA based buffer can use this to start/stop the DMA transfer. Signed-off-by: Lars-Peter Clausen Signed-off-by: Jonathan Cameron --- drivers/iio/industrialio-buffer.c | 36 ++++++++++++++++++++++++++++++- include/linux/iio/buffer.h | 8 +++++++ 2 files changed, 43 insertions(+), 1 deletion(-) diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c index 98a6447a61d3..a4b164a478c4 100644 --- a/drivers/iio/industrialio-buffer.c +++ b/drivers/iio/industrialio-buffer.c @@ -568,6 +568,22 @@ static void iio_buffer_deactivate_all(struct iio_dev *indio_dev) iio_buffer_deactivate(buffer); } +static int iio_buffer_enable(struct iio_buffer *buffer, + struct iio_dev *indio_dev) +{ + if (!buffer->access->enable) + return 0; + return buffer->access->enable(buffer, indio_dev); +} + +static int iio_buffer_disable(struct iio_buffer *buffer, + struct iio_dev *indio_dev) +{ + if (!buffer->access->disable) + return 0; + return buffer->access->disable(buffer, indio_dev); +} + static void iio_buffer_update_bytes_per_datum(struct iio_dev *indio_dev, struct iio_buffer *buffer) { @@ -719,6 +735,7 @@ static int iio_verify_update(struct iio_dev *indio_dev, static int iio_enable_buffers(struct iio_dev *indio_dev, struct iio_device_config *config) { + struct iio_buffer *buffer; int ret; indio_dev->active_scan_mask = config->scan_mask; @@ -753,6 +770,12 @@ static int iio_enable_buffers(struct iio_dev *indio_dev, indio_dev->info->hwfifo_set_watermark(indio_dev, config->watermark); + list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) { + ret = iio_buffer_enable(buffer, indio_dev); + if (ret) + goto err_disable_buffers; + } + indio_dev->currentmode = config->mode; if (indio_dev->setup_ops->postenable) { @@ -760,12 +783,16 @@ static int iio_enable_buffers(struct iio_dev *indio_dev, if (ret) { dev_dbg(&indio_dev->dev, "Buffer not started: postenable failed (%d)\n", ret); - goto err_run_postdisable; + goto err_disable_buffers; } } return 0; +err_disable_buffers: + list_for_each_entry_continue_reverse(buffer, &indio_dev->buffer_list, + buffer_list) + iio_buffer_disable(buffer, indio_dev); err_run_postdisable: indio_dev->currentmode = INDIO_DIRECT_MODE; if (indio_dev->setup_ops->postdisable) @@ -778,6 +805,7 @@ static int iio_enable_buffers(struct iio_dev *indio_dev, static int iio_disable_buffers(struct iio_dev *indio_dev) { + struct iio_buffer *buffer; int ret = 0; int ret2; @@ -798,6 +826,12 @@ static int iio_disable_buffers(struct iio_dev *indio_dev) ret = ret2; } + list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) { + ret2 = iio_buffer_disable(buffer, indio_dev); + if (ret2 && !ret) + ret = ret2; + } + indio_dev->currentmode = INDIO_DIRECT_MODE; if (indio_dev->setup_ops->postdisable) { diff --git a/include/linux/iio/buffer.h b/include/linux/iio/buffer.h index 4d99a53d1fe7..2ec3ad58e8a0 100644 --- a/include/linux/iio/buffer.h +++ b/include/linux/iio/buffer.h @@ -33,6 +33,11 @@ struct iio_buffer; * storage. * @set_bytes_per_datum:set number of bytes per datum * @set_length: set number of datums in buffer + * @enable: called if the buffer is attached to a device and the + * device starts sampling. Calls are balanced with + * @disable. + * @disable: called if the buffer is attached to a device and the + * device stops sampling. Calles are balanced with @enable. * @release: called when the last reference to the buffer is dropped, * should free all resources allocated by the buffer. * @modes: Supported operating modes by this buffer type @@ -58,6 +63,9 @@ struct iio_buffer_access_funcs { int (*set_bytes_per_datum)(struct iio_buffer *buffer, size_t bpd); int (*set_length)(struct iio_buffer *buffer, int length); + int (*enable)(struct iio_buffer *buffer, struct iio_dev *indio_dev); + int (*disable)(struct iio_buffer *buffer, struct iio_dev *indio_dev); + void (*release)(struct iio_buffer *buffer); unsigned int modes; -- 2.45.2