[PATCH 1/2] drivers: gpio: Add support for PCF8574T.

From: Tóth János via B4 Relay
Date: Mon Feb 17 2025 - 08:08:50 EST


From: Tóth János <gomba007@xxxxxxxxx>

Add support for the PCF8574T 8-bit I2C I/O expander.

The driver is tested with:
+ tools/lsgpio
+ tools/gpio-hammer
+ some LEDs

[1] https://www.nxp.com/docs/en/data-sheet/PCF8574_PCF8574A.pdf

Signed-off-by: Tóth János <gomba007@xxxxxxxxx>
---
drivers/gpio/Kconfig | 2 +-
drivers/gpio/gpio-pcf857x.c | 2 ++
2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 98b4d1633b25..d7cdc3cc1b00 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -1193,7 +1193,7 @@ config GPIO_PCF857X
Most of these parts are from NXP, though TI is a second source for
some of them. Compatible models include:

- 8 bits: pcf8574, pcf8574a, pca8574, pca8574a,
+ 8 bits: pcf8574, pcf8574a, pcf8574t, pca8574, pca8574a,
pca9670, pca9672, pca9674, pca9674a,
max7328, max7329

diff --git a/drivers/gpio/gpio-pcf857x.c b/drivers/gpio/gpio-pcf857x.c
index 7c57eaeb0afe..2464c527a4e8 100644
--- a/drivers/gpio/gpio-pcf857x.c
+++ b/drivers/gpio/gpio-pcf857x.c
@@ -20,6 +20,7 @@
static const struct i2c_device_id pcf857x_id[] = {
{ "pcf8574", 8 },
{ "pcf8574a", 8 },
+ { "pcf8574t", 8 },
{ "pca8574", 8 },
{ "pca9670", 8 },
{ "pca9672", 8 },
@@ -38,6 +39,7 @@ MODULE_DEVICE_TABLE(i2c, pcf857x_id);
static const struct of_device_id pcf857x_of_table[] = {
{ .compatible = "nxp,pcf8574", (void *)8 },
{ .compatible = "nxp,pcf8574a", (void *)8 },
+ { .compatible = "nxp,pcf8574t", (void *)8 },
{ .compatible = "nxp,pca8574", (void *)8 },
{ .compatible = "nxp,pca9670", (void *)8 },
{ .compatible = "nxp,pca9672", (void *)8 },

--
2.34.1