Re: [U-Boot] [ v2 03/10] video: add support of MIPI DSI interface

On 13 July 2018 at 06:11, Yannick Fertré yannick.fertre@st.com wrote:

Mipi_display.c contains a set of dsi helpers. This file is a copy of file drm_mipi_dsi.c (linux kernel).

Signed-off-by: Yannick Fertré yannick.fertre@st.com

drivers/video/Kconfig | 9 + drivers/video/Makefile | 1 + drivers/video/mipi_display.c | 817 +++++++++++++++++++++++++++++++++++++++++++ include/mipi_display.h | 257 +++++++++++++- 4 files changed, 1083 insertions(+), 1 deletion(-) create mode 100644 drivers/video/mipi_display.c

diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig index 5ee9032..560da1a 100644 --- a/drivers/video/Kconfig +++ b/drivers/video/Kconfig @@ -73,6 +73,15 @@ config VIDEO_ANSI Enable ANSI escape sequence decoding for a more fully functional console.

+config VIDEO_MIPI_DSI

•   bool "Support MIPI DSI interface"
  

•   depends on DM_VIDEO
  

•   default y if DM_VIDEO
  

Why default y? Many boards won't use MIPI.

•   help
  

•     Support MIPI DSI interface for driving a MIPI compatible device.
  

•     The MIPI Display Serial Interface (MIPI DSI) defines a high-speed
  

•     serial interface between a host processor and a display module.
  

config CONSOLE_NORMAL

[..]

diff --git a/include/mipi_display.h b/include/mipi_display.h index ddcc8ca..5c3dbbe 100644 --- a/include/mipi_display.h +++ b/include/mipi_display.h @@ -4,12 +4,16 @@

• Copyright (C) 2010 Guennadi Liakhovetski g.liakhovetski@gmx.de
• Copyright (C) 2006 Nokia Corporation

• • Author: Imre Deak imre.deak@nokia.com

• • Copyright (C) 2018 STMicroelectronics - All Rights Reserved
• • Author(s): Imre Deak imre.deak@nokia.com

• •        Yannick Fertre <yannick.fertre@st.com>
    

• •        Philippe Cornu <philippe.cornu@st.com>
    

  • This program is free software; you can redistribute it and/or modify
  • it under the terms of the GNU General Public License version 2 as
  • published by the Free Software Foundation.
  */

#ifndef MIPI_DISPLAY_H #define MIPI_DISPLAY_H

@@ -115,6 +119,14 @@ enum { MIPI_DCS_READ_MEMORY_CONTINUE = 0x3E, MIPI_DCS_SET_TEAR_SCANLINE = 0x44, MIPI_DCS_GET_SCANLINE = 0x45,

•   MIPI_DCS_SET_DISPLAY_BRIGHTNESS = 0x51,         /* MIPI DCS 1.3 */
  

•   MIPI_DCS_GET_DISPLAY_BRIGHTNESS = 0x52,         /* MIPI DCS 1.3 */
  

•   MIPI_DCS_WRITE_CONTROL_DISPLAY  = 0x53,         /* MIPI DCS 1.3 */
  

•   MIPI_DCS_GET_CONTROL_DISPLAY    = 0x54,         /* MIPI DCS 1.3 */
  

•   MIPI_DCS_WRITE_POWER_SAVE       = 0x55,         /* MIPI DCS 1.3 */
  

•   MIPI_DCS_GET_POWER_SAVE         = 0x56,         /* MIPI DCS 1.3 */
  

•   MIPI_DCS_SET_CABC_MIN_BRIGHTNESS = 0x5E,        /* MIPI DCS 1.3 */
  

•   MIPI_DCS_GET_CABC_MIN_BRIGHTNESS = 0x5F,        /* MIPI DCS 1.3 */
    MIPI_DCS_READ_DDB_START         = 0xA1,
    MIPI_DCS_READ_DDB_CONTINUE      = 0xA8,
  

}; @@ -127,4 +139,247 @@ enum { #define MIPI_DCS_PIXEL_FMT_8BIT 2 #define MIPI_DCS_PIXEL_FMT_3BIT 1

+struct mipi_dsi_host; +struct mipi_dsi_device;

+/* request ACK from peripheral */ +#define MIPI_DSI_MSG_REQ_ACK BIT(0) +/* use Low Power Mode to transmit message */ +#define MIPI_DSI_MSG_USE_LPM BIT(1)

+/**

• • struct mipi_dsi_msg - read/write DSI buffer
• • @channel: virtual channel id
• • @type: payload data type
• • @flags: flags controlling this message transmission
• • @tx_len: length of @tx_buf
• • @tx_buf: data to be written
• • @rx_len: length of @rx_buf
• • @rx_buf: data to be read, or NULL
• */

+struct mipi_dsi_msg {

•   u8 channel;
  

•   u8 type;
  

•   u16 flags;
  

•   size_t tx_len;
  

•   const void *tx_buf;
  

•   size_t rx_len;
  

•   void *rx_buf;
  

+};

+bool mipi_dsi_packet_format_is_short(u8 type); +bool mipi_dsi_packet_format_is_long(u8 type);

+/**

• • struct mipi_dsi_packet - represents a MIPI DSI packet in protocol format
• • @size: size (in bytes) of the packet
• • @header: the four bytes that make up the header (Data ID, Word Count or

• • Packet Data, and ECC)
    

• • @payload_length: number of bytes in the payload
• • @payload: a pointer to a buffer containing the payload, if any
• */

+struct mipi_dsi_packet {

•   size_t size;
  

•   u8 header[4];
  

•   size_t payload_length;
  

•   const u8 *payload;
  

+};

+int mipi_dsi_create_packet(struct mipi_dsi_packet *packet,

•                      const struct mipi_dsi_msg *msg);
  

+/**

• • struct mipi_dsi_host_ops - DSI bus operations
• • @attach: attach DSI device to DSI host
• • @detach: detach DSI device from DSI host
• • @transfer: transmit a DSI packet
• • DSI packets transmitted by .transfer() are passed in as mipi_dsi_msg
• • structures. This structure contains information about the type of packet
• • being transmitted as well as the transmit and receive buffers. When an
• • error is encountered during transmission, this function will return a
• • negative error code. On success it shall return the number of bytes
• • transmitted for write packets or the number of bytes received for read
• • packets.
• • Note that typically DSI packet transmission is atomic, so the .transfer()
• • function will seldomly return anything other than the number of bytes
• • contained in the transmit buffer on success.
• */

+struct mipi_dsi_host_ops {

•   int (*attach)(struct mipi_dsi_host *host,
  

•                 struct mipi_dsi_device *dsi);
  

•   int (*detach)(struct mipi_dsi_host *host,
  

•                 struct mipi_dsi_device *dsi);
  

•   ssize_t (*transfer)(struct mipi_dsi_host *host,
  

•                       const struct mipi_dsi_msg *msg);
  

This looks like an interface that should use driver model?

+int mipi_dsi_attach(struct mipi_dsi_device *dsi); +int mipi_dsi_detach(struct mipi_dsi_device *dsi); +int mipi_dsi_pixel_format_to_bpp(enum mipi_dsi_pixel_format fmt);

Should there be a MIPI uclass?

[..]

+ssize_t mipi_dsi_dcs_write_buffer(struct mipi_dsi_device *dsi,

•                             const void *data, size_t len);
  

These functions all need full function comments.

+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,

•                     size_t len);
  

+int mipi_dsi_dcs_nop(struct mipi_dsi_device *dsi); +int mipi_dsi_dcs_soft_reset(struct mipi_dsi_device *dsi); +int mipi_dsi_dcs_get_power_mode(struct mipi_dsi_device *dsi, u8 *mode); +int mipi_dsi_dcs_get_pixel_format(struct mipi_dsi_device *dsi, u8 *format); +int mipi_dsi_dcs_enter_sleep_mode(struct mipi_dsi_device *dsi); +int mipi_dsi_dcs_exit_sleep_mode(struct mipi_dsi_device *dsi); +int mipi_dsi_dcs_set_display_off(struct mipi_dsi_device *dsi); +int mipi_dsi_dcs_set_display_on(struct mipi_dsi_device *dsi); +int mipi_dsi_dcs_set_column_address(struct mipi_dsi_device *dsi, u16 start,

•                               u16 end);
  

+int mipi_dsi_dcs_set_page_address(struct mipi_dsi_device *dsi, u16 start,

•                             u16 end);
  

+int mipi_dsi_dcs_set_tear_off(struct mipi_dsi_device *dsi); +int mipi_dsi_dcs_set_tear_on(struct mipi_dsi_device *dsi,

•                        enum mipi_dsi_dcs_tear_mode mode);
  

+int mipi_dsi_dcs_set_pixel_format(struct mipi_dsi_device *dsi, u8 format); +int mipi_dsi_dcs_set_tear_scanline(struct mipi_dsi_device *dsi, u16 scanline); +int mipi_dsi_dcs_set_display_brightness(struct mipi_dsi_device *dsi,

•                                   u16 brightness);
  

+int mipi_dsi_dcs_get_display_brightness(struct mipi_dsi_device *dsi,

•                                   u16 *brightness);
  

#endif

1.9.1

Regards, Simon