hw: gpio: implement gpio-pwr driver for qemu reset/poweroff

Implement gpio-pwr driver to allow reboot and poweroff machine.
This is simple driver with just 2 gpios lines. Current use case
is to reboot and poweroff virt machine in secure mode. Secure
pl066 gpio chip is needed for that.

Signed-off-by: Maxim Uvarov <maxim.uvarov@linaro.org>
Reviewed-by: Hao Wu <wuhaotsh@google.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

hw/gpio/Kconfig

@@ -8,5 +8,8 @@ config PL061
 config GPIO_KEY
     bool
 
+config GPIO_PWR
+    bool
+
 config SIFIVE_GPIO
     bool

hw/gpio/gpio_pwr.c

@@ -0,0 +1,70 @@
+/*
+ * GPIO qemu power controller
+ *
+ * Copyright (c) 2020 Linaro Limited
+ *
+ * Author: Maxim Uvarov <maxim.uvarov@linaro.org>
+ *
+ * Virtual gpio driver which can be used on top of pl061
+ * to reboot and shutdown qemu virtual machine. One of use
+ * case is gpio driver for secure world application (ARM
+ * Trusted Firmware.).
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+/*
+ * QEMU interface:
+ * two named input GPIO lines:
+ *   'reset' : when asserted, trigger system reset
+ *   'shutdown' : when asserted, trigger system shutdown
+ */
+
+#include "qemu/osdep.h"
+#include "hw/sysbus.h"
+#include "sysemu/runstate.h"
+
+#define TYPE_GPIOPWR "gpio-pwr"
+OBJECT_DECLARE_SIMPLE_TYPE(GPIO_PWR_State, GPIOPWR)
+
+struct GPIO_PWR_State {
+    SysBusDevice parent_obj;
+};
+
+static void gpio_pwr_reset(void *opaque, int n, int level)
+{
+    if (level) {
+        qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
+    }
+}
+
+static void gpio_pwr_shutdown(void *opaque, int n, int level)
+{
+    if (level) {
+        qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_SHUTDOWN);
+    }
+}
+
+static void gpio_pwr_init(Object *obj)
+{
+    DeviceState *dev = DEVICE(obj);
+
+    qdev_init_gpio_in_named(dev, gpio_pwr_reset, "reset", 1);
+    qdev_init_gpio_in_named(dev, gpio_pwr_shutdown, "shutdown", 1);
+}
+
+static const TypeInfo gpio_pwr_info = {
+    .name          = TYPE_GPIOPWR,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(GPIO_PWR_State),
+    .instance_init = gpio_pwr_init,
+};
+
+static void gpio_pwr_register_types(void)
+{
+    type_register_static(&gpio_pwr_info);
+}
+
+type_init(gpio_pwr_register_types)

hw/gpio/meson.build

@@ -1,5 +1,6 @@
 softmmu_ss.add(when: 'CONFIG_E500', if_true: files('mpc8xxx.c'))
 softmmu_ss.add(when: 'CONFIG_GPIO_KEY', if_true: files('gpio_key.c'))
+softmmu_ss.add(when: 'CONFIG_GPIO_PWR', if_true: files('gpio_pwr.c'))
 softmmu_ss.add(when: 'CONFIG_MAX7310', if_true: files('max7310.c'))
 softmmu_ss.add(when: 'CONFIG_PL061', if_true: files('pl061.c'))
 softmmu_ss.add(when: 'CONFIG_PUV3', if_true: files('puv3_gpio.c'))