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Subject: Re: [PATCH v3 3/5] ipmi: kcs: aspeed: Adapt to new LPC DTS layout
To:     "Chia-Wei, Wang" <chiawei_wang@aspeedtech.com>,
        lee.jones@linaro.org, robh+dt@kernel.org, joel@jms.id.au,
        andrew@aj.id.au, linus.walleij@linaro.org, minyard@acm.org,
        devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-aspeed@lists.ozlabs.org, linux-kernel@vger.kernel.org,
        openbmc@lists.ozlabs.org
Cc:     BMC-SW@aspeedtech.com, cyrilbur@gmail.com, rlippert@google.com
References: <20201221055623.31463-1-chiawei_wang@aspeedtech.com>
 <20201221055623.31463-4-chiawei_wang@aspeedtech.com>
From:   Haiyue Wang <haiyue.wang@linux.intel.com>
Message-ID: <12d347b6-168b-11d2-b906-18164afb1724@linux.intel.com>
Date:   Mon, 21 Dec 2020 15:53:44 +0800
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On 12/21/2020 13:56, Chia-Wei, Wang wrote:
> Add check against LPC device v2 compatible string to
> ensure that the fixed device tree layout is adopted.
> The LPC register offsets are also fixed accordingly.
>
> Signed-off-by: Chia-Wei, Wang <chiawei_wang@aspeedtech.com>
> ---
>   drivers/char/ipmi/kcs_bmc_aspeed.c | 35 ++++++++++++++++++------------
>   1 file changed, 21 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/char/ipmi/kcs_bmc_aspeed.c b/drivers/char/ipmi/kcs_bmc_aspeed.c
> index a140203c079b..6283bfef4ea7 100644
> --- a/drivers/char/ipmi/kcs_bmc_aspeed.c
> +++ b/drivers/char/ipmi/kcs_bmc_aspeed.c
> @@ -27,7 +27,6 @@
>   
>   #define KCS_CHANNEL_MAX     4
>   
> -/* mapped to lpc-bmc@0 IO space */
>   #define LPC_HICR0            0x000
>   #define     LPC_HICR0_LPC3E          BIT(7)
>   #define     LPC_HICR0_LPC2E          BIT(6)
> @@ -52,15 +51,13 @@
>   #define LPC_STR1             0x03C
>   #define LPC_STR2             0x040
>   #define LPC_STR3             0x044
> -
> -/* mapped to lpc-host@80 IO space */
> -#define LPC_HICRB            0x080
> +#define LPC_HICRB            0x100
>   #define     LPC_HICRB_IBFIF4         BIT(1)
>   #define     LPC_HICRB_LPC4E          BIT(0)
> -#define LPC_LADR4            0x090
> -#define LPC_IDR4             0x094
> -#define LPC_ODR4             0x098
> -#define LPC_STR4             0x09C
> +#define LPC_LADR4            0x110
> +#define LPC_IDR4             0x114
> +#define LPC_ODR4             0x118
> +#define LPC_STR4             0x11C
>   
>   struct aspeed_kcs_bmc {
>   	struct regmap *map;
> @@ -345,15 +342,25 @@ static int aspeed_kcs_probe(struct platform_device *pdev)
>   {
>   	struct device *dev = &pdev->dev;
>   	struct kcs_bmc *kcs_bmc;
> -	struct device_node *np;
> +	struct device_node *kcs_np;
> +	struct device_node *lpc_np;
>   	int rc;
>   

I think you can just use 'np' to do LPC compatible checking:

np = pdev->dev.of_node->parent;

if (!of_device_is_compatible(lpc_np, "aspeed,ast2400-lpc-v2") &&
     !of_device_is_compatible(lpc_np, "aspeed,ast2500-lpc-v2") &&
     !of_device_is_compatible(lpc_np, "aspeed,ast2600-lpc-v2")) {
	dev_err(dev, "unsupported LPC device binding\n");
	return -ENODEV;
}


before:

np = pdev->dev.of_node;
if (of_device_is_compatible(np, "aspeed,ast2400-kcs-bmc") ||
     of_device_is_compatible(np, "aspeed,ast2500-kcs-bmc"))

Then the patch is clear. ;-)

> -	np = pdev->dev.of_node;
> -	if (of_device_is_compatible(np, "aspeed,ast2400-kcs-bmc") ||
> -			of_device_is_compatible(np, "aspeed,ast2500-kcs-bmc"))
> +	kcs_np = dev->of_node;
> +	lpc_np = kcs_np->parent;
> +
> +	if (!of_device_is_compatible(lpc_np, "aspeed,ast2400-lpc-v2") &&
> +	    !of_device_is_compatible(lpc_np, "aspeed,ast2500-lpc-v2") &&
> +	    !of_device_is_compatible(lpc_np, "aspeed,ast2600-lpc-v2")) {
> +		dev_err(dev, "unsupported LPC device binding\n");
> +		return -ENODEV;
> +	}
> +
> +	if (of_device_is_compatible(kcs_np, "aspeed,ast2400-kcs-bmc") ||
> +			of_device_is_compatible(kcs_np, "aspeed,ast2500-kcs-bmc"))
>   		kcs_bmc = aspeed_kcs_probe_of_v1(pdev);
> -	else if (of_device_is_compatible(np, "aspeed,ast2400-kcs-bmc-v2") ||
> -			of_device_is_compatible(np, "aspeed,ast2500-kcs-bmc-v2"))
> +	else if (of_device_is_compatible(kcs_np, "aspeed,ast2400-kcs-bmc-v2") ||
> +			of_device_is_compatible(kcs_np, "aspeed,ast2500-kcs-bmc-v2"))
>   		kcs_bmc = aspeed_kcs_probe_of_v2(pdev);
>   	else
>   		return -EINVAL;