dslinux/linux-2.6.x/drivers/mmc scsd_c.c scsd_s.S

[Malcolm]

On 8/27/06, amadeus <dslinux_amadeus at user.in-berlin.de> wrote:

> Log Message:
> Rewrite of SD driver to allow 32 MByte GBA ROM space used as RAM

Some of the changes may do that, but it's a misleading comment.

> +/* Structure for device-specific functions in assembler.
> +*/
> +struct sd_functions {
> +       /* Test if the card is present.
> +          Return != 0 if present. */
> +       int     (*detect_card) (void);
> +
> +       /* Say if the data transfer is 1 or 4 bit.
> +          Return != 0 if 4 bit. */
> +       int     (*transfer_nibbles) (void);
> +
> +       /* Write at minimum 8 clock cycles to the card.
> +          Wait max. 1ms for the CMD line to become HIGH.
> +          Send a command to the card. Skip 2 Z bits.
> +           data = pointer to start of command. 32bit aligned.
> +           len  = length of the command (including CRC7).
> +          Return != 0 if OK, 0 if timeout. */
> +       int     (*send_command) (u8 *data, int len);
> +
> +       /* Wait max. 1ms for the CMD line to become LOW.
> +          Read a response from the device and skip 2 Z bits.
> +           data = pointer to start of response buffer. 32bit aligned.
> +           len  = number of bytes to read(including CRC).
> +          Return != 0 if OK, 0 if timeout. */
> +       int     (*read_response) (u8* data, int len);
> +
> +       /* Wait for the DATA line to become HIGH.
> +          Return != 0 if OK, 0 if timeout.
> +          Maximum length of testing is 1ms. */
> +       int     (*wait_ready) (void);
> +
> +       /* Write a start bit, send a Data block incl. CRC.
> +          Write the end bit. Skip 2 Z bits.
> +           Wait max. 1ms for the start of the CRC response.
> +          Check the CRC response.
> +          data = pointer to start of data. 32bit aligned.
> +          len  = number of bytes to send.
> +          Return != 0 if OK, 0 if CRC missing or error. */
> +       int     (*send_data) (u8 *data, int len);
> +
> +       /* Wait max 1ms for the DATA line to become LOW.
> +          Receive a Data block and CRC, skip the end bit.
> +          data = pointer to start of data. 32bit aligned.
> +          len  = number of bytes to receive (incl. CRC)
> +          Return != 0 if OK, 0 if timeout. */
> +       int     (*read_data) (u8 *data, int len);
> +
> +       /* Read the write protect switch.
> +          Return != 0 if readonly, 0 if r/w.
> +          When in doubt, return 0. */
> +       int     (*read_only) (void);
> +
> +       /* Write at minimum 8 clock cycles to the card. */
> +       void    (*send_clocks) (void);
> +};

I specifically told you not to do this.

The MMC layer handles using different drivers for different devices.

Don't stick support for different devices in one driver.


Also "Structure for device-specific functions in assembler."
"in assembler"?!
Don't write an M3SD driver in assembler.

-- 
Malcolm Parsons