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Date:   Thu, 14 Sep 2023 11:02:24 -0500
From:   Nishanth Menon <nm@ti.com>
To:     Neha Malcom Francis <n-francis@ti.com>
CC:     <ssantosh@kernel.org>, <linux-kernel@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>, <u-kumar1@ti.com>
Subject: Re: [PATCH] soc: ti: k3-socinfo: Revamp driver to accommodate
 different rev structs
Message-ID: <20230914160224.doytoq2bbvymuieh@onslaught>
References: <20230914074426.1901226-1-n-francis@ti.com>
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In-Reply-To: <20230914074426.1901226-1-n-francis@ti.com>
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On 13:14-20230914, Neha Malcom Francis wrote:
> k3-socinfo.c driver assumes silicon revisions to be 1.0, 2.0 etc. for
> every platform. However this typical style is not followed by J721E
> (1.0, 1.1) and need not be followed by upcoming silicon revisions as
> well. Adapt the driver to be similar to its U-Boot counterpart
> (drivers/soc/soc_ti_k3.c) that accounts for this difference on the basis
> of partno/family. While at it, modify driver to be more understandable.

Don't mix so many things up in a single patch.

> 
> Signed-off-by: Neha Malcom Francis <n-francis@ti.com>
> ---
> This patch tries to revive an earlier attempt [1] and also works off of
> those review comments, sending it as a new patch since the approach is
> slightly different.
> 
> [1] https://lore.kernel.org/all/20230607080349.26671-1-t-konduru@ti.com/
> 
>  drivers/soc/ti/k3-socinfo.c | 112 +++++++++++++++++++++++++-----------
>  1 file changed, 80 insertions(+), 32 deletions(-)
> 
> diff --git a/drivers/soc/ti/k3-socinfo.c b/drivers/soc/ti/k3-socinfo.c
> index 6ea9b8c7d335..1e7a32b5b63f 100644
> --- a/drivers/soc/ti/k3-socinfo.c
> +++ b/drivers/soc/ti/k3-socinfo.c
> @@ -20,7 +20,7 @@
>   *  31-28 VARIANT	Device variant
>   *  27-12 PARTNO	Part number
>   *  11-1  MFG		Indicates TI as manufacturer (0x17)
> - *  1			Always 1
> + *  0			Always 1

Looks like a typo you are fixing, but no information in commit message.

>   */
>  #define CTRLMMR_WKUP_JTAGID_VARIANT_SHIFT	(28)
>  #define CTRLMMR_WKUP_JTAGID_VARIANT_MASK	GENMASK(31, 28)
> @@ -33,33 +33,81 @@
>  
>  #define CTRLMMR_WKUP_JTAGID_MFG_TI		0x17
>  
> -static const struct k3_soc_id {
> -	unsigned int id;
> -	const char *family_name;
> -} k3_soc_ids[] = {
> -	{ 0xBB5A, "AM65X" },
> -	{ 0xBB64, "J721E" },
> -	{ 0xBB6D, "J7200" },
> -	{ 0xBB38, "AM64X" },
> -	{ 0xBB75, "J721S2"},
> -	{ 0xBB7E, "AM62X" },
> -	{ 0xBB80, "J784S4" },
> -	{ 0xBB8D, "AM62AX" },
> -	{ 0xBB9D, "AM62PX" },
> +#define JTAG_ID_PARTNO_AM65X		0xBB5A
> +#define JTAG_ID_PARTNO_J721E		0xBB64
> +#define JTAG_ID_PARTNO_J7200		0xBB6D
> +#define JTAG_ID_PARTNO_AM64X		0xBB38
> +#define JTAG_ID_PARTNO_J721S2		0xBB75
> +#define JTAG_ID_PARTNO_AM62X		0xBB7E
> +#define JTAG_ID_PARTNO_J784S4		0xBB80
> +#define JTAG_ID_PARTNO_AM62AX		0xBB8D
> +#define JTAG_ID_PARTNO_AM62PX		0xBB9D
> +
> +static char *j721e_rev_string_map[] = {
> +	"1.0", "1.1",
> +};
> +
> +static char *typical_rev_string_map[] = {

use k3_ name space please for vars.

> +	"1.0", "2.0", "3.0",
>  };
>  
>  static int
>  k3_chipinfo_partno_to_names(unsigned int partno,
>  			    struct soc_device_attribute *soc_dev_attr)
>  {
> -	int i;
> +	switch (partno) {
> +	case JTAG_ID_PARTNO_AM62AX:
> +		soc_dev_attr->family = "AM62AX";
> +		break;
> +	case JTAG_ID_PARTNO_AM62PX:
> +		soc_dev_attr->family = "AM62PX";
> +		break;
> +	case JTAG_ID_PARTNO_AM62X:
> +		soc_dev_attr->family = "AM62X";
> +		break;
> +	case JTAG_ID_PARTNO_AM64X:
> +		soc_dev_attr->family = "AM64X";
> +		break;
> +	case JTAG_ID_PARTNO_AM65X:
> +		soc_dev_attr->family = "AM65X";
> +		break;
> +	case JTAG_ID_PARTNO_J7200:
> +		soc_dev_attr->family = "J7200";
> +		break;
> +	case JTAG_ID_PARTNO_J721E:
> +		soc_dev_attr->family = "J721E";
> +		break;
> +	case JTAG_ID_PARTNO_J721S2:
> +		soc_dev_attr->family = "J721S2";
> +		break;
> +	case JTAG_ID_PARTNO_J784S4:
> +		soc_dev_attr->family = "J784S4";
> +		break;
> +	default:
> +		return -EINVAL;
> +	};
> +	return 0;
> +};
>  
> -	for (i = 0; i < ARRAY_SIZE(k3_soc_ids); i++)
> -		if (partno == k3_soc_ids[i].id) {
> -			soc_dev_attr->family = k3_soc_ids[i].family_name;
> -			return 0;
> -		}

Why redo the family attribute? That is JTAG standard and handling is
valid and implementation is optimal - no sense in churning here.

> +static int k3_chipinfo_variant_to_sr(unsigned int partno, unsigned int variant,
> +				     struct soc_device_attribute *soc_dev_attr)
> +{
> +	switch (partno) {
> +	case JTAG_ID_PARTNO_J721E:
> +		if (variant >= ARRAY_SIZE(j721e_rev_string_map))
> +			goto bail;
> +		soc_dev_attr->revision = kasprintf(GFP_KERNEL, "SR%s",
> +						   j721e_rev_string_map[variant]);
> +		break;
> +	default:
> +		if (variant >= ARRAY_SIZE(typical_rev_string_map))
> +			goto bail;
> +		soc_dev_attr->revision = kasprintf(GFP_KERNEL, "SR%s",
> +						   typical_rev_string_map[variant]);
> +	}
> +	return 0;
>  
> +bail:
>  	return -EINVAL;
>  }
>  
> @@ -70,10 +118,10 @@ static int k3_chipinfo_probe(struct platform_device *pdev)
>  	struct device *dev = &pdev->dev;
>  	struct soc_device *soc_dev;
>  	struct regmap *regmap;
> -	u32 partno_id;
> -	u32 variant;
>  	u32 jtag_id;
>  	u32 mfg;
> +	u32 partno_id;
> +	u32 variant;
>  	int ret;
>  
>  	regmap = device_node_to_regmap(node);
> @@ -92,28 +140,28 @@ static int k3_chipinfo_probe(struct platform_device *pdev)
>  		return -ENODEV;
>  	}
>  
> -	variant = (jtag_id & CTRLMMR_WKUP_JTAGID_VARIANT_MASK) >>
> -		  CTRLMMR_WKUP_JTAGID_VARIANT_SHIFT;
> -	variant++;
> -
>  	partno_id = (jtag_id & CTRLMMR_WKUP_JTAGID_PARTNO_MASK) >>
>  		 CTRLMMR_WKUP_JTAGID_PARTNO_SHIFT;
>  
> +	variant = (jtag_id & CTRLMMR_WKUP_JTAGID_VARIANT_MASK) >>
> +		  CTRLMMR_WKUP_JTAGID_VARIANT_SHIFT;
> +
no need to relocate the code - just call the chip_info_to_sr

>  	soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
>  	if (!soc_dev_attr)
>  		return -ENOMEM;
>  
> -	soc_dev_attr->revision = kasprintf(GFP_KERNEL, "SR%x.0", variant);
> -	if (!soc_dev_attr->revision) {
> -		ret = -ENOMEM;
> +	ret = k3_chipinfo_partno_to_names(partno_id, soc_dev_attr);
> +	if (ret) {
> +		dev_err(dev, "Unknown SoC JTAGID[0x%08X]\n", jtag_id);
> +		ret = -ENODEV;
>  		goto err;
>  	}
>  
> -	ret = k3_chipinfo_partno_to_names(partno_id, soc_dev_attr);
> +	ret = k3_chipinfo_variant_to_sr(partno_id, variant, soc_dev_attr);
>  	if (ret) {
> -		dev_err(dev, "Unknown SoC JTAGID[0x%08X]\n", jtag_id);
> +		dev_err(dev, "Unknown revision for %s\n", soc_dev_attr->family);
>  		ret = -ENODEV;
> -		goto err_free_rev;
> +		goto err;
>  	}
>  
>  	node = of_find_node_by_path("/");
> -- 
> 2.34.1
> 

-- 
Regards,
Nishanth Menon
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