Re: [PATCH 3/3] serial: amba-pl011: add ACPI support to AMBA probe

From: Rafael J. Wysocki
Date: Mon Nov 30 2015 - 20:52:07 EST


On Wednesday, September 30, 2015 11:38:50 AM Graeme Gregory wrote:
> In ACPI this device is only defined in SBSA mode so
> if we are probing from ACPI use this mode.
>
> Cc: Rafael J. Wysocki <rjw@xxxxxxxxxxxxx>
> Cc: Len Brown <lenb@xxxxxxxxxx>
> Cc: Russell King <linux@xxxxxxxxxxxxxxxx>
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Graeme Gregory <graeme.gregory@xxxxxxxxxx>
> ---
> drivers/tty/serial/amba-pl011.c | 32 +++++++++++++++++++++-----------
> 1 file changed, 21 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
> index fd27e98..55209aa 100644
> --- a/drivers/tty/serial/amba-pl011.c
> +++ b/drivers/tty/serial/amba-pl011.c
> @@ -2368,18 +2368,28 @@ static int pl011_probe(struct amba_device *dev, const struct amba_id *id)
> if (!uap)
> return -ENOMEM;
>
> - uap->clk = devm_clk_get(&dev->dev, NULL);
> - if (IS_ERR(uap->clk))
> - return PTR_ERR(uap->clk);
> -
> - uap->vendor = vendor;
> - uap->lcrh_rx = vendor->lcrh_rx;
> - uap->lcrh_tx = vendor->lcrh_tx;
> - uap->fifosize = vendor->get_fifosize(dev);
> + /* ACPI only defines SBSA variant */
> + if (!ACPI_COMPANION(&dev->dev)) {

It would read more straightforward if you did

if (ACPI_COMPANION(&dev->dev)) {
<handle the ACPI case>
} else {
<handle the non-ACPI case>
}

> + uap->clk = devm_clk_get(&dev->dev, NULL);
> + if (IS_ERR(uap->clk))
> + return PTR_ERR(uap->clk);
> +
> + uap->vendor = vendor;
> + uap->lcrh_rx = vendor->lcrh_rx;
> + uap->lcrh_tx = vendor->lcrh_tx;
> + uap->fifosize = vendor->get_fifosize(dev);
> + uap->port.ops = &amba_pl011_pops;
> + snprintf(uap->type, sizeof(uap->type), "PL011 rev%u",
> + amba_rev(dev));
> + } else {
> + uap->vendor = &vendor_sbsa;
> + uap->fifosize = 32;
> + uap->port.ops = &sbsa_uart_pops;
> + uap->fixed_baud = 115200;
> +
> + snprintf(uap->type, sizeof(uap->type), "SBSA");

This looks sort of heavy-handed.

Is this the only possible configuration of the device in the ACPI case?

> + }
> uap->port.irq = dev->irq[0];
> - uap->port.ops = &amba_pl011_pops;
> -
> - snprintf(uap->type, sizeof(uap->type), "PL011 rev%u", amba_rev(dev));
>
> ret = pl011_setup_port(&dev->dev, uap, &dev->res, portnr);
> if (ret)

Thanks,
Rafael

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