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

[Nelson Chang]

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:j...@phrozen.org] 
Sent: Tuesday, October 04, 2016 3:17 AM
To: Nelson Chang (張家祥); da...@davemloft.net
Cc: n...@openwrt.org; netdev@vger.kernel.org;
linux-media...@lists.infradead.org; nelsonch...@gmail.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.ch...@mediatek.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;
>