netdev - RE: [PATCH net-next 1/3] net: ethernet: mediatek: get the chip id by ETHDMASYS registers

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Date:   Tue, 4 Oct 2016 20:12:40 +0800
From:   Nelson Chang <nelson.chang@...iatek.com>
To:     <john@...ozen.org>, <davem@...emloft.net>
CC:     <nbd@...nwrt.org>, <netdev@...r.kernel.org>,
        <linux-mediatek@...ts.infradead.org>, <nelsonch.tw@...il.com>
Subject: RE: [PATCH net-next 1/3] net: ethernet: mediatek: get the chip id
 by ETHDMASYS registers

Hi John,

Thanks for your review!
I will modify that as below. Would you think it is okay?

static int mtk_get_chip_id(struct mtk_eth *eth, u32 *chip_id)
{
	u32 val[2], id[4];

	regmap_read(eth->ethsys, ETHSYS_CHIPID0_3, &val[0]);
	regmap_read(eth->ethsys, ETHSYS_CHIPID4_7, &val[1]);

	id[3] = ((val[0] >> 16) & 0xff) - '0';
	id[2] = ((val[0] >> 24) & 0xff) - '0';
	id[1] = (val[1] & 0xff) - '0';
	id[0] = ((val[1] >> 8) & 0xff) - '0';

	*chip_id = (id[3] * 1000) + (id[2] * 100) +
		   (id[1] * 10) + id[0];

	if (!(*chip_id)) {
		dev_err(eth->dev, "failed to get chip id\n");
		return -ENODEV;
	}

	dev_info(eth->dev, "chip id = %d\n", *chip_id);

	return 0;
}
...
static int mtk_probe(struct platform_device *pdev)
{
	...
	err = mtk_get_chip_id(eth, &eth->chip_id);
	if (err)
		return err;
	...
}


Nelson

-----Original Message-----
From: John Crispin [mailto:john@...ozen.org] 
Sent: Tuesday, October 04, 2016 3:17 AM
To: Nelson Chang (張家祥); davem@...emloft.net
Cc: nbd@...nwrt.org; netdev@...r.kernel.org;
linux-mediatek@...ts.infradead.org; nelsonch.tw@...il.com
Subject: Re: [PATCH net-next 1/3] net: ethernet: mediatek: get the chip
id by ETHDMASYS registers

Hi Nelson,

comments inline

On 03/10/2016 09:18, Nelson Chang wrote:
> The driver gets the chip id by ETHSYS_CHIPID0_3/ETHSYS_CHIPID4_7 
> registers in mtk_probe().
> 
> Signed-off-by: Nelson Chang <nelson.chang@...iatek.com>
> ---
>  drivers/net/ethernet/mediatek/mtk_eth_soc.c | 27 
> +++++++++++++++++++++++++++  
> drivers/net/ethernet/mediatek/mtk_eth_soc.h |  5 +++++
>  2 files changed, 32 insertions(+)
> 
> diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c 
> b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
> index ad4ab97..a3e4ae6 100644
> --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
> +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
> @@ -2323,6 +2323,27 @@ free_netdev:
>  	return err;
>  }
>  
> +static u32 mtk_get_chip_id(struct mtk_eth *eth) {
> +	u32 val[2], id[4];
> +	u32 chip_id;
> +
> +	regmap_read(eth->ethsys, ETHSYS_CHIPID0_3, &val[0]);
> +	regmap_read(eth->ethsys, ETHSYS_CHIPID4_7, &val[1]);
> +
> +	id[3] = ((val[0] >> 16) & 0xff) - '0';
> +	id[2] = ((val[0] >> 24) & 0xff) - '0';
> +	id[1] = (val[1] & 0xff) - '0';
> +	id[0] = ((val[1] >> 8) & 0xff) - '0';
> +
> +	chip_id = (id[3] * 1000) + (id[2] * 100) +
> +		  (id[1] * 10) + id[0];
> +
> +	dev_info(eth->dev, "chip id = %d\n", chip_id);

the chip id is printed here

> +	return chip_id;
> +}
> +
>  static int mtk_probe(struct platform_device *pdev)  {
>  	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 
> 0); @@ -2388,6 +2409,12 @@ static int mtk_probe(struct platform_device
*pdev)
>  	if (err)
>  		return err;
>  
> +	eth->chip_id = mtk_get_chip_id(eth);
> +	if (!eth->chip_id) {
> +		dev_err(&pdev->dev, "failed to get chip id\n");
> +		return -ENODEV;
> +	}
> +

and the error check happens here. maybe you could move the dev_err to
the above function.

	John

>  	for_each_child_of_node(pdev->dev.of_node, mac_np) {
>  		if (!of_device_is_compatible(mac_np,
>  					     "mediatek,eth-mac"))
> diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.h 
> b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
> index 3003195..a5b422b 100644
> --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
> +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
> @@ -342,6 +342,10 @@
>  #define GPIO_BIAS_CTRL		0xed0
>  #define GPIO_DRV_SEL10		0xf00
>  
> +/* ethernet subsystem chip id register */
> +#define ETHSYS_CHIPID0_3	0x0
> +#define ETHSYS_CHIPID4_7	0x4
> +
>  /* ethernet subsystem config register */
>  #define ETHSYS_SYSCFG0		0x14
>  #define SYSCFG0_GE_MASK		0x3
> @@ -534,6 +538,7 @@ struct mtk_eth {
>  	unsigned long			sysclk;
>  	struct regmap			*ethsys;
>  	struct regmap			*pctl;
> +	u32				chip_id;
>  	bool				hwlro;
>  	atomic_t			dma_refcnt;
>  	struct mtk_tx_ring		tx_ring;
>