diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst index e2a0585915b3..2734b8a34541 100644 --- a/Documentation/gpu/todo.rst +++ b/Documentation/gpu/todo.rst @@ -494,6 +494,24 @@ Contact: Douglas Anderson Level: Starter/Intermediate +Transition away from using mipi_dsi_*_write_seq() +------------------------------------------------- + +The macros mipi_dsi_generic_write_seq() and mipi_dsi_dcs_write_seq() are +non-intuitive because, if there are errors, they return out of the *caller's* +function. We should move all callers to use mipi_dsi_generic_write_seq_multi() +and mipi_dsi_dcs_write_seq_multi() macros instead. + +Once all callers are transitioned, the macros and the functions that they call, +mipi_dsi_generic_write_chatty() and mipi_dsi_dcs_write_buffer_chatty(), can +probably be removed. Alternatively, if people feel like the _multi() variants +are overkill for some use cases, we could keep the mipi_dsi_*_write_seq() +variants but change them not to return out of the caller. + +Contact: Douglas Anderson + +Level: Starter + Core refactorings ================= diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c index 4d2685d5a6e0..26c7383406c1 100644 --- a/drivers/gpu/drm/drm_mipi_dsi.c +++ b/drivers/gpu/drm/drm_mipi_dsi.c @@ -792,6 +792,34 @@ int mipi_dsi_generic_write_chatty(struct mipi_dsi_device *dsi, } EXPORT_SYMBOL(mipi_dsi_generic_write_chatty); +/** + * mipi_dsi_generic_write_multi() - mipi_dsi_generic_write_chatty() w/ accum_err + * @ctx: Context for multiple DSI transactions + * @payload: buffer containing the payload + * @size: size of payload buffer + * + * Like mipi_dsi_generic_write_chatty() but deals with errors in a way that + * makes it convenient to make several calls in a row. + */ +void mipi_dsi_generic_write_multi(struct mipi_dsi_multi_context *ctx, + const void *payload, size_t size) +{ + struct mipi_dsi_device *dsi = ctx->dsi; + struct device *dev = &dsi->dev; + ssize_t ret; + + if (ctx->accum_err) + return; + + ret = mipi_dsi_generic_write(dsi, payload, size); + if (ret < 0) { + ctx->accum_err = ret; + dev_err(dev, "sending generic data %*ph failed: %d\n", + (int)size, payload, ctx->accum_err); + } +} +EXPORT_SYMBOL(mipi_dsi_generic_write_multi); + /** * mipi_dsi_generic_read() - receive data using a generic read packet * @dsi: DSI peripheral device @@ -908,6 +936,34 @@ int mipi_dsi_dcs_write_buffer_chatty(struct mipi_dsi_device *dsi, } EXPORT_SYMBOL(mipi_dsi_dcs_write_buffer_chatty); +/** + * mipi_dsi_dcs_write_buffer_multi - mipi_dsi_dcs_write_buffer_chatty() w/ accum_err + * @ctx: Context for multiple DSI transactions + * @data: buffer containing data to be transmitted + * @len: size of transmission buffer + * + * Like mipi_dsi_dcs_write_buffer_chatty() but deals with errors in a way that + * makes it convenient to make several calls in a row. + */ +void mipi_dsi_dcs_write_buffer_multi(struct mipi_dsi_multi_context *ctx, + const void *data, size_t len) +{ + struct mipi_dsi_device *dsi = ctx->dsi; + struct device *dev = &dsi->dev; + ssize_t ret; + + if (ctx->accum_err) + return; + + ret = mipi_dsi_dcs_write_buffer(dsi, data, len); + if (ret < 0) { + ctx->accum_err = ret; + dev_err(dev, "sending dcs data %*ph failed: %d\n", + (int)len, data, ctx->accum_err); + } +} +EXPORT_SYMBOL(mipi_dsi_dcs_write_buffer_multi); + /** * mipi_dsi_dcs_write() - send DCS write command * @dsi: DSI peripheral device diff --git a/include/drm/drm_mipi_dsi.h b/include/drm/drm_mipi_dsi.h index 6d68d9927f46..5e9cad541bd6 100644 --- a/include/drm/drm_mipi_dsi.h +++ b/include/drm/drm_mipi_dsi.h @@ -197,6 +197,27 @@ struct mipi_dsi_device { struct drm_dsc_config *dsc; }; +/** + * struct mipi_dsi_multi_context - Context to call multiple MIPI DSI funcs in a row + */ +struct mipi_dsi_multi_context { + /** + * @dsi: Pointer to the MIPI DSI device + */ + struct mipi_dsi_device *dsi; + + /** + * @accum_err: Storage for the accumulated error over the multiple calls + * + * Init to 0. If a function encounters an error then the error code + * will be stored here. If you call a function and this points to a + * non-zero value then the function will be a noop. This allows calling + * a function many times in a row and just checking the error at the + * end to see if any of them failed. + */ + int accum_err; +}; + #define MIPI_DSI_MODULE_PREFIX "mipi-dsi:" #define to_mipi_dsi_device(__dev) container_of_const(__dev, struct mipi_dsi_device, dev) @@ -258,6 +279,8 @@ ssize_t mipi_dsi_generic_write(struct mipi_dsi_device *dsi, const void *payload, size_t size); int mipi_dsi_generic_write_chatty(struct mipi_dsi_device *dsi, const void *payload, size_t size); +void mipi_dsi_generic_write_multi(struct mipi_dsi_multi_context *ctx, + const void *payload, size_t size); ssize_t mipi_dsi_generic_read(struct mipi_dsi_device *dsi, const void *params, size_t num_params, void *data, size_t size); @@ -283,6 +306,8 @@ ssize_t mipi_dsi_dcs_write_buffer(struct mipi_dsi_device *dsi, const void *data, size_t len); int mipi_dsi_dcs_write_buffer_chatty(struct mipi_dsi_device *dsi, const void *data, size_t len); +void mipi_dsi_dcs_write_buffer_multi(struct mipi_dsi_multi_context *ctx, + const void *data, size_t len); ssize_t mipi_dsi_dcs_write(struct mipi_dsi_device *dsi, u8 cmd, const void *data, size_t len); ssize_t mipi_dsi_dcs_read(struct mipi_dsi_device *dsi, u8 cmd, void *data, @@ -319,6 +344,9 @@ int mipi_dsi_dcs_get_display_brightness_large(struct mipi_dsi_device *dsi, * This macro will print errors for you and will RETURN FROM THE CALLING * FUNCTION (yes this is non-intuitive) upon error. * + * Because of the non-intuitive return behavior, THIS MACRO IS DEPRECATED. + * Please replace calls of it with mipi_dsi_generic_write_seq_multi(). + * * @dsi: DSI peripheral device * @seq: buffer containing the payload */ @@ -331,12 +359,30 @@ int mipi_dsi_dcs_get_display_brightness_large(struct mipi_dsi_device *dsi, return ret; \ } while (0) +/** + * mipi_dsi_generic_write_seq_multi - transmit data using a generic write packet + * + * This macro will print errors for you and error handling is optimized for + * callers that call this multiple times in a row. + * + * @ctx: Context for multiple DSI transactions + * @seq: buffer containing the payload + */ +#define mipi_dsi_generic_write_seq_multi(ctx, seq...) \ + do { \ + static const u8 d[] = { seq }; \ + mipi_dsi_generic_write_multi(ctx, d, ARRAY_SIZE(d)); \ + } while (0) + /** * mipi_dsi_dcs_write_seq - transmit a DCS command with payload * * This macro will print errors for you and will RETURN FROM THE CALLING * FUNCTION (yes this is non-intuitive) upon error. * + * Because of the non-intuitive return behavior, THIS MACRO IS DEPRECATED. + * Please replace calls of it with mipi_dsi_dcs_write_seq_multi(). + * * @dsi: DSI peripheral device * @cmd: Command * @seq: buffer containing data to be transmitted @@ -350,6 +396,22 @@ int mipi_dsi_dcs_get_display_brightness_large(struct mipi_dsi_device *dsi, return ret; \ } while (0) +/** + * mipi_dsi_dcs_write_seq_multi - transmit a DCS command with payload + * + * This macro will print errors for you and error handling is optimized for + * callers that call this multiple times in a row. + * + * @ctx: Context for multiple DSI transactions + * @cmd: Command + * @seq: buffer containing data to be transmitted + */ +#define mipi_dsi_dcs_write_seq_multi(ctx, cmd, seq...) \ + do { \ + static const u8 d[] = { cmd, seq }; \ + mipi_dsi_dcs_write_buffer_multi(ctx, d, ARRAY_SIZE(d)); \ + } while (0) + /** * struct mipi_dsi_driver - DSI driver * @driver: device driver model driver