Synopsis

typedef struct {
  CTL_GFX_DRIVER_t core;
  CTL_SPI_DEVICE_t *dev;
  void (*set_reset)(CTL_GFX_CONTROLLER_s *, int);
  void (*set_window)(CTL_GFX_CONTROLLER_s *, int , int , int , int);
  void (*write_register)(CTL_GFX_CONTROLLER_s *, unsigned , unsigned);
  void (*write_pixels)(CTL_GFX_CONTROLLER_s *, unsigned , int);
  void (*move_cursor)(CTL_GFX_CONTROLLER_s *, int , int);
  void (*write_command)(CTL_GFX_CONTROLLER_s *, int);
  void (*write_data_8b)(CTL_GFX_CONTROLLER_s *, int);
  void (*write_data_16b)(CTL_GFX_CONTROLLER_s *, int);
  void (*write_data_24b)(CTL_GFX_CONTROLLER_s *, int);
  void (*set_dc)(CTL_GFX_CONTROLLER_s *, int);
  unsigned char __window_trashed;
  unsigned char controller_address;
  unsigned char controller_caset;
  unsigned char controller_paset;
  unsigned char controller_ramwr;
} CTL_GFX_CONTROLLER_t;

Description

CTL_GFX_CONTROLLER_t contains the instance data for a graphics driver that is implemented by a simple windowing, bus-interfaced (or otherwise) graphics controller. Typical graphics controllers provide a register-data interface that is abstracted by the write_register and write_pixels methods, and an operating window that is abstracted by the set_window method.

core

The core graphics driver.

dev

The SPI device used to control SPI-attached controllers. If the device is attached using I2C or a parallel bus, this member must be set to zero.

set_reset

A method to control the reset signal to the controller. Many drivers simply ignore this method and rely on the system's power-on reset or higher-level code to reset the controller.

set_window

Method to set the window that write_pixels works on.

move_cursor

Method to set the cursor to within the window (if required by the controller).

write_register

Method to write data to register reg.

write_pixels

Method to write pixel to graphics RAM n times.

write_command

A method to write a command to the graphics controller. Graphics controllers typically separate commands from data by a single bit that is presented on an address line or digital control signal, within the SPI protocol or within the I2C protocol.

write_data_8b

Write 8 bits of data to the graphics controller.

write_data_16b

Write 16 bits of data to the graphics controller in the byte order appropriate for the controller.

write_data_24b

Write 16 bits of data to the graphics controller in the byte order appropriate for the controller.

set_dc

Set the state of the D/C or RS signal for SPI-connected graphics controllers. Graphics controllers that are interfaced in 8-bit SPI mode require a separate D/C or RS signal to indicate whether the frames transferred over the SPI bus are to be interpreted as data or commands. For I2C, 9-bit SPI, and parallel-interfaced controllers, this member must be zero.

controller_address

Internal address for I2C-connected and SPI-connected graphics controllers (if required).

__window_trashed

Internal flag indicating whether the window is invalid and requires initializing before writing to GRAM.

controller_caset

An internal member set by the device driver that corresponds to the "column address" command of the graphics controller.

controller_paset

An internal member set by the device driver that corresponds to the "page address" command of the graphics controller.

controller_ramwr

An internal member set by the device driver that corresponds to the "RAM write" command of the graphics controller.