diff options
author | Thierry Reding <treding@nvidia.com> | 2014-07-21 13:47:10 (GMT) |
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committer | Thierry Reding <treding@nvidia.com> | 2014-11-13 12:55:36 (GMT) |
commit | 960dd616f61c8482b3f9d01fa6623576fb74503c (patch) | |
tree | d62b57a143804dc3404ad57f8ecd767d6f5202b3 /drivers/gpu/drm/drm_mipi_dsi.c | |
parent | 9eb491f3eed26eb7edf4bf4b1a549895fb3301ea (diff) | |
download | linux-960dd616f61c8482b3f9d01fa6623576fb74503c.tar.xz |
drm/dsi: Make mipi_dsi_dcs_{read,write}() symmetrical
Currently the mipi_dsi_dcs_write() function requires the DCS command
byte to be embedded within the write buffer whereas mipi_dsi_dcs_read()
has a separate parameter. Make them more symmetrical by adding an extra
command parameter to mipi_dsi_dcs_write().
The S6E8AA0 driver relies on the old asymmetric API and there's concern
that moving to the new API may be less efficient. Provide a new function
with the old semantics for those cases and make the S6E8AA0 driver use
it instead.
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Diffstat (limited to 'drivers/gpu/drm/drm_mipi_dsi.c')
-rw-r--r-- | drivers/gpu/drm/drm_mipi_dsi.c | 77 |
1 files changed, 65 insertions, 12 deletions
diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c index 0cc030a..388c3ab 100644 --- a/drivers/gpu/drm/drm_mipi_dsi.c +++ b/drivers/gpu/drm/drm_mipi_dsi.c @@ -333,13 +333,19 @@ int mipi_dsi_create_packet(struct mipi_dsi_packet *packet, EXPORT_SYMBOL(mipi_dsi_create_packet); /** - * mipi_dsi_dcs_write - send DCS write command - * @dsi: DSI device - * @data: pointer to the command followed by parameters - * @len: length of @data + * mipi_dsi_dcs_write_buffer() - transmit a DCS command with payload + * @dsi: DSI peripheral device + * @data: buffer containing data to be transmitted + * @len: size of transmission buffer + * + * This function will automatically choose the right data type depending on + * the command payload length. + * + * Return: The number of bytes successfully transmitted or a negative error + * code on failure. */ -ssize_t mipi_dsi_dcs_write(struct mipi_dsi_device *dsi, const void *data, - size_t len) +ssize_t mipi_dsi_dcs_write_buffer(struct mipi_dsi_device *dsi, + const void *data, size_t len) { struct mipi_dsi_msg msg = { .channel = dsi->channel, @@ -350,12 +356,15 @@ ssize_t mipi_dsi_dcs_write(struct mipi_dsi_device *dsi, const void *data, switch (len) { case 0: return -EINVAL; + case 1: msg.type = MIPI_DSI_DCS_SHORT_WRITE; break; + case 2: msg.type = MIPI_DSI_DCS_SHORT_WRITE_PARAM; break; + default: msg.type = MIPI_DSI_DCS_LONG_WRITE; break; @@ -363,16 +372,60 @@ ssize_t mipi_dsi_dcs_write(struct mipi_dsi_device *dsi, const void *data, return mipi_dsi_device_transfer(dsi, &msg); } +EXPORT_SYMBOL(mipi_dsi_dcs_write_buffer); + +/** + * mipi_dsi_dcs_write() - send DCS write command + * @dsi: DSI peripheral device + * @cmd: DCS command + * @data: buffer containing the command payload + * @len: command payload length + * + * This function will automatically choose the right data type depending on + * the command payload length. + * + * Return: The number of bytes successfully transmitted or a negative error + * code on failure. + */ +ssize_t mipi_dsi_dcs_write(struct mipi_dsi_device *dsi, u8 cmd, + const void *data, size_t len) +{ + ssize_t err; + size_t size; + u8 *tx; + + if (len > 0) { + size = 1 + len; + + tx = kmalloc(size, GFP_KERNEL); + if (!tx) + return -ENOMEM; + + /* concatenate the DCS command byte and the payload */ + tx[0] = cmd; + memcpy(&tx[1], data, len); + } else { + tx = &cmd; + size = 1; + } + + err = mipi_dsi_dcs_write_buffer(dsi, tx, size); + + if (len > 0) + kfree(tx); + + return err; +} EXPORT_SYMBOL(mipi_dsi_dcs_write); /** - * mipi_dsi_dcs_read - send DCS read request command - * @dsi: DSI device - * @cmd: DCS read command - * @data: pointer to read buffer - * @len: length of @data + * mipi_dsi_dcs_read() - send DCS read request command + * @dsi: DSI peripheral device + * @cmd: DCS command + * @data: buffer in which to receive data + * @len: size of receive buffer * - * Function returns number of read bytes or error code. + * Return: The number of bytes read or a negative error code on failure. */ ssize_t mipi_dsi_dcs_read(struct mipi_dsi_device *dsi, u8 cmd, void *data, size_t len) |