Re: [PATCH v7 2/3] riscv: virt: Use Goldfish RTC device

[Anup Patel]

On Wed, Nov 6, 2019 at 2:05 PM Anup Patel <address@hidden> wrote:
>
> We extend QEMU RISC-V virt machine by adding Goldfish RTC device
> to it. This will allow Guest Linux to sync it's local date/time
> with Host date/time via RTC device.
>
> Signed-off-by: Anup Patel <address@hidden>
> Reviewed-by: Palmer Dabbelt <address@hidden>
> Acked-by: Palmer Dabbelt <address@hidden>
> Reviewed-by: Alistair Francis <address@hidden>
> ---
>  hw/riscv/Kconfig        |  1 +
>  hw/riscv/virt.c         | 15 +++++++++++++++
>  include/hw/riscv/virt.h |  2 ++
>  3 files changed, 18 insertions(+)
>
> diff --git a/hw/riscv/Kconfig b/hw/riscv/Kconfig
> index b12660b9f8..ff9fbe958a 100644
> --- a/hw/riscv/Kconfig
> +++ b/hw/riscv/Kconfig
> @@ -34,6 +34,7 @@ config RISCV_VIRT
>      select PCI
>      select HART
>      select SERIAL
> +    select GOLDFISH_RTC
>      select VIRTIO_MMIO
>      select PCI_EXPRESS_GENERIC_BRIDGE
>      select PFLASH_CFI01
> diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c
> index cc8f311e6b..818678a4b2 100644
> --- a/hw/riscv/virt.c
> +++ b/hw/riscv/virt.c
> @@ -58,6 +58,7 @@ static const struct MemmapEntry {
>      [VIRT_DEBUG] =       {        0x0,         0x100 },
>      [VIRT_MROM] =        {     0x1000,       0x11000 },
>      [VIRT_TEST] =        {   0x100000,        0x1000 },
> +    [VIRT_RTC] =         {   0x101000,        0x1000 },
>      [VIRT_CLINT] =       {  0x2000000,       0x10000 },
>      [VIRT_PLIC] =        {  0xc000000,     0x4000000 },
>      [VIRT_UART0] =       { 0x10000000,         0x100 },
> @@ -376,6 +377,17 @@ static void create_fdt(RISCVVirtState *s, const struct 
> MemmapEntry *memmap,
>      qemu_fdt_setprop_cell(fdt, nodename, "interrupt-parent", plic_phandle);
>      qemu_fdt_setprop_cell(fdt, nodename, "interrupts", UART0_IRQ);
>
> +    nodename = g_strdup_printf("/rtc@%lx",
> +        (long)memmap[VIRT_RTC].base);
> +    qemu_fdt_add_subnode(fdt, nodename);
> +    qemu_fdt_setprop_string(fdt, nodename, "compatible",
> +        "google,goldfish-rtc");
> +    qemu_fdt_setprop_cells(fdt, nodename, "reg",
> +        0x0, memmap[VIRT_RTC].base,
> +        0x0, memmap[VIRT_RTC].size);
> +    qemu_fdt_setprop_cell(fdt, nodename, "interrupt-parent", plic_phandle);
> +    qemu_fdt_setprop_cell(fdt, nodename, "interrupts", RTC_IRQ);
> +

We cannot create RTC node here because "nodename" is directly
used as "stdout-path" below. Due to this patch, U-Boot S-mode
stops working on QEMU because it see incorrect "stdout-path".

I will quickly send updated v8 series.

>      qemu_fdt_add_subnode(fdt, "/chosen");
>      qemu_fdt_setprop_string(fdt, "/chosen", "stdout-path", nodename);
>      if (cmdline) {
> @@ -579,6 +591,9 @@ static void riscv_virt_board_init(MachineState *machine)
>          0, qdev_get_gpio_in(DEVICE(s->plic), UART0_IRQ), 399193,
>          serial_hd(0), DEVICE_LITTLE_ENDIAN);
>
> +    sysbus_create_simple("goldfish_rtc", memmap[VIRT_RTC].base,
> +        qdev_get_gpio_in(DEVICE(s->plic), RTC_IRQ));
> +
>      virt_flash_create(s);
>
>      for (i = 0; i < ARRAY_SIZE(s->flash); i++) {
> diff --git a/include/hw/riscv/virt.h b/include/hw/riscv/virt.h
> index b17048a93a..e69355efaf 100644
> --- a/include/hw/riscv/virt.h
> +++ b/include/hw/riscv/virt.h
> @@ -44,6 +44,7 @@ enum {
>      VIRT_DEBUG,
>      VIRT_MROM,
>      VIRT_TEST,
> +    VIRT_RTC,
>      VIRT_CLINT,
>      VIRT_PLIC,
>      VIRT_UART0,
> @@ -57,6 +58,7 @@ enum {
>
>  enum {
>      UART0_IRQ = 10,
> +    RTC_IRQ = 11,
>      VIRTIO_IRQ = 1, /* 1 to 8 */
>      VIRTIO_COUNT = 8,
>      PCIE_IRQ = 0x20, /* 32 to 35 */
> --
> 2.17.1
>

Regards,
Anup