On Sat, 5 Sept 2026 at 00:18, Anirudh Srinivasan
<[email protected]> wrote:
> @@ -265,7 +265,8 @@ static void create_fdt_cpu(void *fdt, TTAtlantisSoCState
> *s,
> }
>
> static void create_fdt_uart(void *fdt, const MemMapEntry *mem, int irq,
> - int irqchip_phandle)
> + int irqchip_phandle, uint32_t clk_parent_phandle,
> + uint32_t clk_phandle)
> {
> g_autofree char *name = g_strdup_printf("/soc/serial@%"HWADDR_PRIX,
> mem->base);
> @@ -275,7 +276,8 @@ static void create_fdt_uart(void *fdt, const MemMapEntry
> *mem, int irq,
> qemu_fdt_setprop_sized_cells(fdt, name, "reg", 2, mem->base, 2,
> mem->size);
> qemu_fdt_setprop_cell(fdt, name, "reg-shift", 2);
> qemu_fdt_setprop_cell(fdt, name, "reg-io-width", 4);
> - qemu_fdt_setprop_cell(fdt, name, "clock-frequency", 3686400);
The downside of this is we no longer boot with a Linux build that
lacks the PRCM driver, like the old build that is used for functional
testing in the tree.
I suggest we keep clock-frequency along side the clocks node. New
kernels with the PRCM driver use the clock phandle and calculate the
clock. Old kernels keep booting.
The other option is to drop this patch entirely for now, and revisit
later. I'd prefer keeping clock-frequency along side.
> + qemu_fdt_setprop_cells(fdt, name, "clocks", clk_parent_phandle,
> + clk_phandle);
> qemu_fdt_setprop_cell(fdt, name, "interrupt-parent", irqchip_phandle);
> qemu_fdt_setprop_cells(fdt, name, "interrupts", irq, 0x4);
> @@ -314,8 +318,8 @@ static void create_fdt_i2c(void *fdt, const MemMapEntry
> *mem, uint32_t irq,
> qemu_fdt_setprop_sized_cells(fdt, name, "reg", 2, mem->base, 2,
> mem->size);
> qemu_fdt_setprop_cell(fdt, name, "interrupt-parent", irqchip_phandle);
> qemu_fdt_setprop_cells(fdt, name, "interrupts", irq, 0x4);
> - qemu_fdt_setprop_cell(fdt, name, "clocks", clk_phandle);
> - qemu_fdt_setprop_cell(fdt, name, "clock-frequency", 100000);
This should stay, it's the bus frequency.
clock-frequency:
description: Desired I2C bus clock frequency in Hz
enum: [100000, 400000, 1000000, 3400000]
default: 400000
(or we omit it, and default to 400kHz. Your call).
> + qemu_fdt_setprop_cells(fdt, name, "clocks", clk_parent_phandle,
> + clk_phandle);
This looks good.
> qemu_fdt_setprop_cell(fdt, name, "#address-cells", 1);
> qemu_fdt_setprop_cell(fdt, name, "#size-cells", 0);
> }
