From: Thierry Reding <treding@xxxxxxxxxx>
Implement generic read and write commands. Selection of the proper data
type for packets is done automatically based on the number of parameters
or payload length.
Signed-off-by: Thierry Reding <treding@xxxxxxxxxx>
---
drivers/gpu/drm/drm_mipi_dsi.c | 115 +++++++++++++++++++++++++++++++++++++++++
include/drm/drm_mipi_dsi.h | 6 +++
2 files changed, 121 insertions(+)
diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c
index 27fc6dac5e4a..7cd69273dbad 100644
--- a/drivers/gpu/drm/drm_mipi_dsi.c
+++ b/drivers/gpu/drm/drm_mipi_dsi.c
@@ -229,6 +229,121 @@ int mipi_dsi_set_maximum_return_packet_size(struct mipi_dsi_device *dsi,
EXPORT_SYMBOL(mipi_dsi_set_maximum_return_packet_size);
/**
+ * mipi_dsi_generic_write() - transmit data using a generic write packet
+ * @dsi: DSI peripheral device
+ * @payload: buffer containing the payload
+ * @size: size of payload buffer
+ *
+ * This function will automatically choose the right data type depending on
+ * the payload length.
+ *
+ * Return: The number of bytes transmitted on success or a negative error code
+ * on failure.
+ */
+ssize_t mipi_dsi_generic_write(struct mipi_dsi_device *dsi, const void *payload,
+ size_t size)
+{
+ struct mipi_dsi_msg msg;
+ ssize_t err;
+ u8 *tx;
+
+ memset(&msg, 0, sizeof(msg));
+ msg.channel = dsi->channel;
+ msg.flags = MIPI_DSI_MSG_USE_LPM | MIPI_DSI_MSG_REQ_ACK;
+
+ if (size > 2) {
+ tx = kmalloc(2 + size, GFP_KERNEL);
+ if (!tx)
+ return -ENOMEM;
+
+ tx[0] = (size >> 0) & 0xff;
+ tx[1] = (size >> 8) & 0xff;
+
+ memcpy(tx + 2, payload, size);
+
+ msg.tx_len = 2 + size;
+ msg.tx_buf = tx;
+ } else {
+ msg.tx_buf = payload;
+ msg.tx_len = size;
+ }
+
+ switch (size) {
+ case 0:
+ msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_0_PARAM;
+ break;
+
+ case 1:
+ msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_1_PARAM;
+ break;
+
+ case 2:
+ msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_2_PARAM;
+ break;
+
+ default:
+ msg.type = MIPI_DSI_GENERIC_LONG_WRITE;
+ break;
+ }
+
+ err = dsi->host->ops->transfer(dsi->host, &msg);
+
+ if (size > 2)
+ kfree(tx);
+
+ return err;
+}
+EXPORT_SYMBOL(mipi_dsi_generic_write);
+
+/**
+ * mipi_dsi_generic_read() - receive data using a generic read packet
+ * @dsi: DSI peripheral device
+ * @params: buffer containing the request parameters
+ * @num_params: number of request parameters
+ * @data: buffer in which to return the received data
+ * @size: size of receive buffer
+ *
+ * This function will automatically choose the right data type depending on
+ * the number of parameters passed in.
+ *
+ * Return: The number of bytes successfully read or a negative error code on
+ * failure.
+ */
+ssize_t mipi_dsi_generic_read(struct mipi_dsi_device *dsi, const void *params,
+ size_t num_params, void *data, size_t size)
+{
+ struct mipi_dsi_msg msg;
+
+ memset(&msg, 0, sizeof(msg));
+ msg.channel = dsi->channel;
+ msg.flags = MIPI_DSI_MSG_USE_LPM;
+ msg.tx_len = num_params;
+ msg.tx_buf = params;
+ msg.rx_len = size;
+ msg.rx_buf = data;
+
+ switch (num_params) {
+ case 0:
+ msg.type = MIPI_DSI_GENERIC_READ_REQUEST_0_PARAM;
+ break;
+
+ case 1:
+ msg.type = MIPI_DSI_GENERIC_READ_REQUEST_1_PARAM;
+ break;
+
+ case 2:
+ msg.type = MIPI_DSI_GENERIC_READ_REQUEST_2_PARAM;
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ return dsi->host->ops->transfer(dsi->host, &msg);
+}
+EXPORT_SYMBOL(mipi_dsi_generic_read);
+
+/**
* mipi_dsi_dcs_write_buffer() - transmit a DCS command with payload
* @dsi: DSI peripheral device
* @data: buffer containing data to be transmitted
diff --git a/include/drm/drm_mipi_dsi.h b/include/drm/drm_mipi_dsi.h
index ef50b5d0de57..92ca66306702 100644
--- a/include/drm/drm_mipi_dsi.h
+++ b/include/drm/drm_mipi_dsi.h
@@ -134,6 +134,12 @@ int mipi_dsi_attach(struct mipi_dsi_device *dsi);
int mipi_dsi_detach(struct mipi_dsi_device *dsi);
int mipi_dsi_set_maximum_return_packet_size(struct mipi_dsi_device *dsi,
u16 value);
+
+ssize_t mipi_dsi_generic_write(struct mipi_dsi_device *dsi, 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);
+
ssize_t mipi_dsi_dcs_write_buffer(struct mipi_dsi_device *dsi,
const void *data, size_t len);
ssize_t mipi_dsi_dcs_write(struct mipi_dsi_device *dsi, u8 cmd,
--
2.1.2
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