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[PULL 22/47] misc/pca9552: Let external devices set pca9552 inputs
From: |
Nicholas Piggin |
Subject: |
[PULL 22/47] misc/pca9552: Let external devices set pca9552 inputs |
Date: |
Sat, 24 Feb 2024 01:41:41 +1000 |
From: Glenn Miles <milesg@linux.vnet.ibm.com>
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 <andrew@codeconstruct.com.au>
Signed-off-by: Glenn Miles <milesg@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
hw/misc/pca9552.c | 50 +++++++++++++++++++++++++++++++++------
include/hw/misc/pca9552.h | 3 ++-
2 files changed, 45 insertions(+), 8 deletions(-)
diff --git a/hw/misc/pca9552.c b/hw/misc/pca9552.c
index f00a149d61..2ae13af35e 100644
--- a/hw/misc/pca9552.c
+++ b/hw/misc/pca9552.c
@@ -44,6 +44,8 @@ DECLARE_CLASS_CHECKERS(PCA955xClass, PCA955X,
#define PCA9552_LED_OFF 0x1
#define PCA9552_LED_PWM0 0x2
#define PCA9552_LED_PWM1 0x3
+#define PCA9552_PIN_LOW 0x0
+#define PCA9552_PIN_HIZ 0x1
static const char *led_state[] = {"on", "off", "pwm0", "pwm1"};
@@ -110,22 +112,27 @@ static void pca955x_update_pin_input(PCA955xState *s)
for (i = 0; i < k->pin_count; i++) {
uint8_t input_reg = PCA9552_INPUT0 + (i / 8);
- uint8_t input_shift = (i % 8);
+ uint8_t bit_mask = 1 << (i % 8);
uint8_t config = pca955x_pin_get_config(s, i);
+ uint8_t old_value = s->regs[input_reg] & bit_mask;
+ uint8_t new_value;
switch (config) {
case PCA9552_LED_ON:
/* Pin is set to 0V to turn on LED */
- qemu_set_irq(s->gpio[i], 0);
- s->regs[input_reg] &= ~(1 << input_shift);
+ s->regs[input_reg] &= ~bit_mask;
break;
case PCA9552_LED_OFF:
/*
* Pin is set to Hi-Z to turn off LED and
- * pullup sets it to a logical 1.
+ * pullup sets it to a logical 1 unless
+ * external device drives it low.
*/
- qemu_set_irq(s->gpio[i], 1);
- s->regs[input_reg] |= 1 << input_shift;
+ if (s->ext_state[i] == PCA9552_PIN_LOW) {
+ s->regs[input_reg] &= ~bit_mask;
+ } else {
+ s->regs[input_reg] |= bit_mask;
+ }
break;
case PCA9552_LED_PWM0:
case PCA9552_LED_PWM1:
@@ -133,6 +140,12 @@ static void pca955x_update_pin_input(PCA955xState *s)
default:
break;
}
+
+ /* update irq state only if pin state changed */
+ new_value = s->regs[input_reg] & bit_mask;
+ if (new_value != old_value) {
+ qemu_set_irq(s->gpio_out[i], !!new_value);
+ }
}
}
@@ -340,6 +353,7 @@ static const VMStateDescription pca9552_vmstate = {
VMSTATE_UINT8(len, PCA955xState),
VMSTATE_UINT8(pointer, PCA955xState),
VMSTATE_UINT8_ARRAY(regs, PCA955xState, PCA955X_NR_REGS),
+ VMSTATE_UINT8_ARRAY(ext_state, PCA955xState, PCA955X_PIN_COUNT_MAX),
VMSTATE_I2C_SLAVE(i2c, PCA955xState),
VMSTATE_END_OF_LIST()
}
@@ -358,6 +372,7 @@ static void pca9552_reset(DeviceState *dev)
s->regs[PCA9552_LS2] = 0x55;
s->regs[PCA9552_LS3] = 0x55;
+ memset(s->ext_state, PCA9552_PIN_HIZ, PCA955X_PIN_COUNT_MAX);
pca955x_update_pin_input(s);
s->pointer = 0xFF;
@@ -380,6 +395,26 @@ static void pca955x_initfn(Object *obj)
}
}
+static void pca955x_set_ext_state(PCA955xState *s, int pin, int level)
+{
+ if (s->ext_state[pin] != level) {
+ uint16_t pins_status = pca955x_pins_get_status(s);
+ s->ext_state[pin] = level;
+ pca955x_update_pin_input(s);
+ pca955x_display_pins_status(s, pins_status);
+ }
+}
+
+static void pca955x_gpio_in_handler(void *opaque, int pin, int level)
+{
+
+ PCA955xState *s = PCA955X(opaque);
+ PCA955xClass *k = PCA955X_GET_CLASS(s);
+
+ assert((pin >= 0) && (pin < k->pin_count));
+ pca955x_set_ext_state(s, pin, level);
+}
+
static void pca955x_realize(DeviceState *dev, Error **errp)
{
PCA955xClass *k = PCA955X_GET_CLASS(dev);
@@ -389,7 +424,8 @@ static void pca955x_realize(DeviceState *dev, Error **errp)
s->description = g_strdup("pca-unspecified");
}
- qdev_init_gpio_out(dev, s->gpio, k->pin_count);
+ qdev_init_gpio_out(dev, s->gpio_out, k->pin_count);
+ qdev_init_gpio_in(dev, pca955x_gpio_in_handler, k->pin_count);
}
static Property pca955x_properties[] = {
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 */
};
--
2.42.0
- [PULL 00/47] ppc-for-9.0 queue, Nicholas Piggin, 2024/02/23
- [PULL 01/47] target/ppc: Fix lxv/stxv MSR facility check, Nicholas Piggin, 2024/02/23
- [PULL 12/47] hw/ppc/spapr: Add missing license, Nicholas Piggin, 2024/02/23
- [PULL 15/47] hw/ppc/spapr: Rename 'softmmu' -> 'vhyp_mmu', Nicholas Piggin, 2024/02/23
- [PULL 02/47] target/ppc: Fix crash on machine check caused by ifetch, Nicholas Piggin, 2024/02/23
- [PULL 03/47] tests/avocado: mark boot_linux.py long runtime instead of flaky, Nicholas Piggin, 2024/02/23
- [PULL 06/47] tests/avocado: Add ppc pseries and powernv hash MMU tests, Nicholas Piggin, 2024/02/23
- [PULL 20/47] ppc/pnv: Change powernv default to powernv10, Nicholas Piggin, 2024/02/23
- [PULL 22/47] misc/pca9552: Let external devices set pca9552 inputs,
Nicholas Piggin <=
- [PULL 24/47] ppc/pnv: Add pca9552 to powernv10-rainier for PCIe hotplug power control, Nicholas Piggin, 2024/02/23
- [PULL 11/47] target/ppc: Rename registers to match ISA, Nicholas Piggin, 2024/02/23
- [PULL 17/47] ppc/spapr: Initialize max_cpus limit to SPAPR_IRQ_NR_IPIS., Nicholas Piggin, 2024/02/23
- [PULL 19/47] spapr: Tag pseries-2.1 - 2.11 machines as deprecated, Nicholas Piggin, 2024/02/23
- [PULL 29/47] ppc/pnv: Test pnv i2c master and connected devices, Nicholas Piggin, 2024/02/23
- [PULL 32/47] hw/ppc: N1 chiplet wiring, Nicholas Piggin, 2024/02/23
- [PULL 35/47] target/ppc: Improve timebase register defines naming, Nicholas Piggin, 2024/02/23
- [PULL 33/47] target/ppc: Update gdbstub to read SPR's CFAR, DEC, HDEC, TB-L/U, Nicholas Piggin, 2024/02/23
- [PULL 37/47] ppc/pnv: Add POWER9/10 chiptod model, Nicholas Piggin, 2024/02/23
- [PULL 05/47] tests/avocado: ppc add powernv10 boot_linux_console test, Nicholas Piggin, 2024/02/23