RE: [PATCH] riscv/virt: Add syscon reboot and poweroff DT nodes

[Anup Patel]

> -----Original Message-----
> From: Bin Meng <address@hidden>
> Sent: Monday, November 11, 2019 8:58 PM
> To: Anup Patel <address@hidden>
> Cc: Peter Maydell <address@hidden>; Alistair Francis
> <address@hidden>; Sagar Karandikar <address@hidden>;
> Palmer Dabbelt <address@hidden>; address@hidden; Atish
> Patra <address@hidden>; address@hidden; Christoph Hellwig
> <address@hidden>; Anup Patel <address@hidden>
> Subject: Re: [PATCH] riscv/virt: Add syscon reboot and poweroff DT nodes
> 
> On Mon, Nov 11, 2019 at 9:42 PM Anup Patel <address@hidden> wrote:
> >
> > Correct Palmer's email address.
> >
> > > -----Original Message-----
> > > From: Anup Patel
> > > Sent: Monday, November 11, 2019 7:08 PM
> > > To: Peter Maydell <address@hidden>; Palmer Dabbelt
> > > <address@hidden>; Alistair Francis <address@hidden>;
> > > Sagar Karandikar <address@hidden>
> > > Cc: Atish Patra <address@hidden>; Christoph Hellwig
> > > <address@hidden>; Anup Patel <address@hidden>;
> > > address@hidden; qemu- address@hidden; Anup Patel
> > > <address@hidden>
> > > Subject: [PATCH] riscv/virt: Add syscon reboot and poweroff DT nodes
> > >
> > > The SiFive test device found on virt machine can be used by generic
> > > syscon reboot and poweroff drivers available in Linux kernel.
> > >
> > > This patch updates FDT generation in virt machine so that Linux
> > > kernel can probe and use generic syscon drivers.
> > >
> > > Signed-off-by: Anup Patel <address@hidden>
> > > ---
> > >  hw/riscv/virt.c | 28 ++++++++++++++++++++++++----
> > >  1 file changed, 24 insertions(+), 4 deletions(-)
> > >
> > > diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c index
> > > cc8f311e6b..fdfa359713
> > > 100644
> > > --- a/hw/riscv/virt.c
> > > +++ b/hw/riscv/virt.c
> > > @@ -182,11 +182,11 @@ static void create_fdt(RISCVVirtState *s,
> > > const struct MemmapEntry *memmap,
> > >      uint64_t mem_size, const char *cmdline)  {
> > >      void *fdt;
> > > -    int cpu;
> > > +    int cpu, i;
> > >      uint32_t *cells;
> > >      char *nodename;
> > > -    uint32_t plic_phandle, phandle = 1;
> > > -    int i;
> > > +    const char test_compat[] = "sifive,test0\0syscon";
> > > +    uint32_t plic_phandle, test_phandle, phandle = 1;
> > >      hwaddr flashsize = virt_memmap[VIRT_FLASH].size / 2;
> > >      hwaddr flashbase = virt_memmap[VIRT_FLASH].base;
> > >
> > > @@ -356,13 +356,33 @@ static void create_fdt(RISCVVirtState *s,
> > > const struct MemmapEntry *memmap,
> > >      create_pcie_irq_map(fdt, nodename, plic_phandle);
> > >      g_free(nodename);
> > >
> > > +    test_phandle = phandle++;
> > >      nodename = g_strdup_printf("/test@%lx",
> > >          (long)memmap[VIRT_TEST].base);
> > >      qemu_fdt_add_subnode(fdt, nodename);
> > > -    qemu_fdt_setprop_string(fdt, nodename, "compatible",
> "sifive,test0");
> > > +    qemu_fdt_setprop(fdt, nodename, "compatible",
> > > +                     test_compat, sizeof(test_compat));
> > >      qemu_fdt_setprop_cells(fdt, nodename, "reg",
> > >          0x0, memmap[VIRT_TEST].base,
> > >          0x0, memmap[VIRT_TEST].size);
> > > +    qemu_fdt_setprop_cell(fdt, nodename, "phandle", test_phandle);
> > > +    test_phandle = qemu_fdt_get_phandle(fdt, nodename);
> 
> Is this necessary?

I was doubtful about this line myself but I tried to keep code
consistent with other DT nodes (such as PLIC).

Regards,
Anup

> 
> > > +    g_free(nodename);
> > > +
> > > +    nodename = g_strdup_printf("/reboot");
> > > +    qemu_fdt_add_subnode(fdt, nodename);
> > > +    qemu_fdt_setprop_string(fdt, nodename, "compatible", "syscon-
> > > reboot");
> > > +    qemu_fdt_setprop_cell(fdt, nodename, "regmap", test_phandle);
> > > +    qemu_fdt_setprop_cell(fdt, nodename, "offset", 0x0);
> > > +    qemu_fdt_setprop_cell(fdt, nodename, "value", FINISHER_RESET);
> > > +    g_free(nodename);
> > > +
> > > +    nodename = g_strdup_printf("/poweroff");
> > > +    qemu_fdt_add_subnode(fdt, nodename);
> > > +    qemu_fdt_setprop_string(fdt, nodename, "compatible", "syscon-
> > > poweroff");
> > > +    qemu_fdt_setprop_cell(fdt, nodename, "regmap", test_phandle);
> > > +    qemu_fdt_setprop_cell(fdt, nodename, "offset", 0x0);
> > > +    qemu_fdt_setprop_cell(fdt, nodename, "value", FINISHER_PASS);
> > >      g_free(nodename);
> > >
> > >      nodename = g_strdup_printf("/uart@%lx",
> > > --
> 
> Regards,
> Bin