[PATCH v3 2/2] hw/loongarch/virt: Add FDT table support with acpi ged pm register

[Bibo Mao]

ACPI ged is used for power management on LoongArch virt platform, in
general it is parsed from acpi table. However if system boot directly from
elf kernel, no UEFI bios is provided and acpi table cannot be used also.

Here acpi ged pm register is exposed with FDT table, it is compatbile
with syscon method in FDT table, only that acpi ged pm register is accessed
with 8-bit mode, rather with 32-bit mode.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
---
 hw/loongarch/virt.c | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/hw/loongarch/virt.c b/hw/loongarch/virt.c
index 81b1f9486f..1b85ba80c9 100644
--- a/hw/loongarch/virt.c
+++ b/hw/loongarch/virt.c
@@ -280,6 +280,44 @@ static void fdt_add_rtc_node(LoongArchVirtMachineState 
*lvms,
     g_free(nodename);
 }
 
+static void fdt_add_ged_reset(LoongArchVirtMachineState *lvms)
+{
+    char *name;
+    uint32_t ged_handle;
+    MachineState *ms = MACHINE(lvms);
+    hwaddr base = VIRT_GED_REG_ADDR;
+    hwaddr size = ACPI_GED_REG_COUNT;
+
+    ged_handle = qemu_fdt_alloc_phandle(ms->fdt);
+    name = g_strdup_printf("/ged@%" PRIx64, base);
+    qemu_fdt_add_subnode(ms->fdt, name);
+    qemu_fdt_setprop_string(ms->fdt, name, "compatible", "syscon");
+    qemu_fdt_setprop_cells(ms->fdt, name, "reg", 0x0, base, 0x0, size);
+    /* 8 bit registers */
+    qemu_fdt_setprop_cell(ms->fdt, name, "reg-shift", 0);
+    qemu_fdt_setprop_cell(ms->fdt, name, "reg-io-width", 1);
+    qemu_fdt_setprop_cell(ms->fdt, name, "phandle", ged_handle);
+    ged_handle = qemu_fdt_get_phandle(ms->fdt, name);
+    g_free(name);
+
+    name = g_strdup_printf("/reboot");
+    qemu_fdt_add_subnode(ms->fdt, name);
+    qemu_fdt_setprop_string(ms->fdt, name, "compatible", "syscon-reboot");
+    qemu_fdt_setprop_cell(ms->fdt, name, "regmap", ged_handle);
+    qemu_fdt_setprop_cell(ms->fdt, name, "offset", ACPI_GED_REG_RESET);
+    qemu_fdt_setprop_cell(ms->fdt, name, "value", ACPI_GED_RESET_VALUE);
+    g_free(name);
+
+    name = g_strdup_printf("/poweroff");
+    qemu_fdt_add_subnode(ms->fdt, name);
+    qemu_fdt_setprop_string(ms->fdt, name, "compatible", "syscon-poweroff");
+    qemu_fdt_setprop_cell(ms->fdt, name, "regmap", ged_handle);
+    qemu_fdt_setprop_cell(ms->fdt, name, "offset", ACPI_GED_REG_SLEEP_CTL);
+    qemu_fdt_setprop_cell(ms->fdt, name, "value", ACPI_GED_SLP_EN |
+                          (ACPI_GED_SLP_TYP_S5 << ACPI_GED_SLP_TYP_POS));
+    g_free(name);
+}
+
 static void fdt_add_uart_node(LoongArchVirtMachineState *lvms,
                               uint32_t *pch_pic_phandle, hwaddr base,
                               int irq, bool chosen)
@@ -737,6 +775,7 @@ static void virt_devices_init(DeviceState *pch_pic,
                          qdev_get_gpio_in(pch_pic,
                          VIRT_RTC_IRQ - VIRT_GSI_BASE));
     fdt_add_rtc_node(lvms, pch_pic_phandle);
+    fdt_add_ged_reset(lvms);
 
     /* acpi ged */
     lvms->acpi_ged = create_acpi_ged(pch_pic, lvms);
-- 
2.39.3