include/linux/spi/mcp23s08.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 struct mcp23s08_platform_data {
   3         /* For mcp23s08, up to 4 slaves (numbered 0..3) can share one SPI
   4          * chipselect, each providing 1 gpio_chip instance with 8 gpios.
   5          * For mpc23s17, up to 8 slaves (numbered 0..7) can share one SPI
   6          * chipselect, each providing 1 gpio_chip (port A + port B) with
   7          * 16 gpios.
   8          */
   9         u32 spi_present_mask;
  10
  11         /* "base" is the number of the first GPIO or -1 for dynamic
  12          * assignment. If there are gaps in chip addressing the GPIO
  13          * numbers are sequential .. so for example if only slaves 0
  14          * and 3 are present, their GPIOs range from base to base+15
  15          * (or base+31 for s17 variant).
  16          */
  17         unsigned        base;
  18 };