From ff557c272c21692e9fa4d5a18e2d8989485b00e4 Mon Sep 17 00:00:00 2001 From: Glenn Miles Date: Mon, 5 Feb 2024 17:40:15 +1000 Subject: misc/pca9552: Let external devices set pca9552 inputs Allow external devices to drive pca9552 input pins by adding input GPIO's to the model. This allows a device to connect its output GPIO's to the pca9552 input GPIO's. In order for an external device to set the state of a pca9552 pin, the pin must first be configured for high impedance (LED is off). If the pca9552 pin is configured to drive the pin low (LED is on), then external input will be ignored. Here is a table describing the logical state of a pca9552 pin given the state being driven by the pca9552 and an external device: PCA9552 Configured State | Hi-Z | Low | ------+------+-----+ External Hi-Z | Hi | Low | Device ------+------+-----+ State Low | Low | Low | ------+------+-----+ Reviewed-by: Andrew Jeffery Signed-off-by: Glenn Miles Signed-off-by: Nicholas Piggin --- include/hw/misc/pca9552.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include/hw/misc/pca9552.h') diff --git a/include/hw/misc/pca9552.h b/include/hw/misc/pca9552.h index b6f4e264fe..c36525f0c3 100644 --- a/include/hw/misc/pca9552.h +++ b/include/hw/misc/pca9552.h @@ -30,7 +30,8 @@ struct PCA955xState { uint8_t pointer; uint8_t regs[PCA955X_NR_REGS]; - qemu_irq gpio[PCA955X_PIN_COUNT_MAX]; + qemu_irq gpio_out[PCA955X_PIN_COUNT_MAX]; + uint8_t ext_state[PCA955X_PIN_COUNT_MAX]; char *description; /* For debugging purpose only */ }; -- cgit 1.4.1