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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /include/linux/platform_data/pcf857x.h | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'include/linux/platform_data/pcf857x.h')
-rw-r--r-- | include/linux/platform_data/pcf857x.h | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/include/linux/platform_data/pcf857x.h b/include/linux/platform_data/pcf857x.h new file mode 100644 index 000000000..01d0a3ea3 --- /dev/null +++ b/include/linux/platform_data/pcf857x.h @@ -0,0 +1,45 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __LINUX_PCF857X_H +#define __LINUX_PCF857X_H + +/** + * struct pcf857x_platform_data - data to set up pcf857x driver + * @gpio_base: number of the chip's first GPIO + * @n_latch: optional bit-inverse of initial register value; if + * you leave this initialized to zero the driver will act + * like the chip was just reset + * @setup: optional callback issued once the GPIOs are valid + * @teardown: optional callback issued before the GPIOs are invalidated + * @context: optional parameter passed to setup() and teardown() + * + * In addition to the I2C_BOARD_INFO() state appropriate to each chip, + * the i2c_board_info used with the pcf875x driver must provide its + * platform_data (pointer to one of these structures) with at least + * the gpio_base value initialized. + * + * The @setup callback may be used with the kind of board-specific glue + * which hands the (now-valid) GPIOs to other drivers, or which puts + * devices in their initial states using these GPIOs. + * + * These GPIO chips are only "quasi-bidirectional"; read the chip specs + * to understand the behavior. They don't have separate registers to + * record which pins are used for input or output, record which output + * values are driven, or provide access to input values. That must be + * inferred by reading the chip's value and knowing the last value written + * to it. If you leave n_latch initialized to zero, that last written + * value is presumed to be all ones (as if the chip were just reset). + */ +struct pcf857x_platform_data { + unsigned gpio_base; + unsigned n_latch; + + int (*setup)(struct i2c_client *client, + int gpio, unsigned ngpio, + void *context); + void (*teardown)(struct i2c_client *client, + int gpio, unsigned ngpio, + void *context); + void *context; +}; + +#endif /* __LINUX_PCF857X_H */ |