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