Re: [PATCH 3/6] hw/arm: Add I2C device tree for NPCM750 eval board

[Peter Maydell <peter.maydell@linaro.org>]

On Tue, 26 Jan 2021 at 19:32, Hao Wu <wuhaotsh@google.com> wrote:
>
> Add an I2C device tree for NPCM750 evaluation board.
>
> Reviewed-by: Doug Evans<dje@google.com>
> Reviewed-by: Tyrong Ting<kfting@nuvoton.com>
> Signed-off-by: Hao Wu <wuhaotsh@google.com>

Slightly confusing commit message, because "device tree"
usually means the data structure describing hardware for Linux
(https://www.kernel.org/doc/html/latest/devicetree/usage-model.html).

Something like "Create the I2C tmp105 temperature sensor devices"
would be clearer, I think.

> ---
>  hw/arm/npcm7xx_boards.c | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
>
> diff --git a/hw/arm/npcm7xx_boards.c b/hw/arm/npcm7xx_boards.c
> index 3fdd5cab01..2d82f48848 100644
> --- a/hw/arm/npcm7xx_boards.c
> +++ b/hw/arm/npcm7xx_boards.c
> @@ -98,6 +98,20 @@ static NPCM7xxState *npcm7xx_create_soc(MachineState *machine,
>      return NPCM7XX(obj);
>  }
>
> +static I2CBus *npcm7xx_i2c_get_bus(NPCM7xxState *soc, uint32_t num)
> +{
> +    g_assert(num < ARRAY_SIZE(soc->smbus));
> +    return I2C_BUS(qdev_get_child_bus(DEVICE(&soc->smbus[num]), "i2c-bus"));
> +}
> +
> +static void npcm750_evb_i2c_init(NPCM7xxState *soc)
> +{
> +    i2c_slave_create_simple(npcm7xx_i2c_get_bus(soc, 0), "tmp105", 0x48);
> +    i2c_slave_create_simple(npcm7xx_i2c_get_bus(soc, 1), "tmp105", 0x48);
> +    i2c_slave_create_simple(npcm7xx_i2c_get_bus(soc, 2), "tmp105", 0x48);
> +    i2c_slave_create_simple(npcm7xx_i2c_get_bus(soc, 6), "tmp105", 0x48);

I assume these correspond to temperature sensors on the real board.
Might be worth having a comment saying what their function is
(I'm guessing they're measuring temperature of different bits of
the board somehow?)

> +}
> +
>  static void npcm750_evb_init(MachineState *machine)
>  {
>      NPCM7xxState *soc;
> @@ -108,6 +122,7 @@ static void npcm750_evb_init(MachineState *machine)
>
>      npcm7xx_load_bootrom(machine, soc);
>      npcm7xx_connect_flash(&soc->fiu[0], 0, "w25q256", drive_get(IF_MTD, 0, 0));
> +    npcm750_evb_i2c_init(soc);
>      npcm7xx_load_kernel(machine, soc);
>  }
>
> --
> 2.30.0.365.g02bc693789-goog

thanks
-- PMM