hw/loongarch/virt: Add FDT table support with acpi ged pm register

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>
Reviewed-by: Song Gao <gaosong@loongson.cn>
Tested-by: Song Gao <gaosong@loongson.cn>
Message-Id: <20240918014206.2165821-3-maobibo@loongson.cn>
Signed-off-by: Song Gao <gaosong@loongson.cn>

1 files changed, 39 insertions, 0 deletions

diff --git a/hw/loongarch/virt.c b/hw/loongarch/virt.c
index ddd886f..9a635d1 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);