[U-Boot] [PATCH v4 3/3] cmd: mdio: Add new parameter to access MMD PHY registers

[Vladimir Oltean]

On 1/24/19 10:56 AM, Carlo Caione wrote:
> Two new parameters (rmmd and wmmd) are added to allow the `mdio` command
> to access the content of the MMD PHY registers.
> 
> Signed-off-by: Carlo Caione <ccaione at baylibre.com>
> Acked-by: Joe Hershberger <joe.hershberger at ni.com>
> ---
>   cmd/mdio.c | 52 +++++++++++++++++++++++++++++++++++++---------------
>   1 file changed, 37 insertions(+), 15 deletions(-)
> 
> diff --git a/cmd/mdio.c b/cmd/mdio.c
> index 184868063a..5138db505a 100644
> --- a/cmd/mdio.c
> +++ b/cmd/mdio.c
> @@ -43,7 +43,7 @@ static int mdio_write_ranges(struct phy_device *phydev, struct mii_dev *bus,
>   			     int addrlo,
>   			     int addrhi, int devadlo, int devadhi,
>   			     int reglo, int reghi, unsigned short data,
> -			     int extended)
> +			     int extended, int mmd)
>   {
>   	int addr, devad, reg;
>   	int err = 0;
> @@ -51,12 +51,15 @@ static int mdio_write_ranges(struct phy_device *phydev, struct mii_dev *bus,
>   	for (addr = addrlo; addr <= addrhi; addr++) {
>   		for (devad = devadlo; devad <= devadhi; devad++) {
>   			for (reg = reglo; reg <= reghi; reg++) {
> -				if (!extended)
> -					err = bus->write(bus, addr, devad,
> -							 reg, data);
> -				else
> +				if (mmd)
> +					err = phy_write_mmd(phydev, devad, reg,
> +							    data);
> +				else if (extended)
>   					err = phydev->drv->writeext(phydev,
>   							addr, devad, reg, data);
> +				else
> +					err = bus->write(bus, addr, devad,
> +							 reg, data);
>   
>   				if (err)
>   					goto err_out;
> @@ -71,7 +74,7 @@ err_out:
>   static int mdio_read_ranges(struct phy_device *phydev, struct mii_dev *bus,
>   			    int addrlo,
>   			    int addrhi, int devadlo, int devadhi,
> -			    int reglo, int reghi, int extended)
> +			    int reglo, int reghi, int extended, int mmd)
>   {
>   	int addr, devad, reg;
>   
> @@ -83,11 +86,13 @@ static int mdio_read_ranges(struct phy_device *phydev, struct mii_dev *bus,
>   			for (reg = reglo; reg <= reghi; reg++) {
>   				int val;
>   
> -				if (!extended)
> -					val = bus->read(bus, addr, devad, reg);
> -				else
> +				if (mmd)
> +					val = phy_read_mmd(phydev, devad, reg);
> +				else if (extended)
>   					val = phydev->drv->readext(phydev, addr,
>   						devad, reg);
> +				else
> +					val = bus->read(bus, addr, devad, reg);
>   
>   				if (val < 0) {
>   					printf("Error\n");
> @@ -189,6 +194,7 @@ static int do_mdio(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
>   	struct mii_dev *bus;
>   	struct phy_device *phydev = NULL;
>   	int extended = 0;
> +	int mmd = 0;
>   
>   	if (argc < 2)
>   		return CMD_RET_USAGE;
> @@ -222,14 +228,26 @@ static int do_mdio(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
>   				bus = phydev->bus;
>   				extended = 1;
>   			} else {
> -				return -1;
> +				return CMD_RET_FAILURE;
>   			}
>   
>   			if (!phydev->drv ||
>   			    (!phydev->drv->writeext && (op[0] == 'w')) ||
>   			    (!phydev->drv->readext && (op[0] == 'r'))) {
>   				puts("PHY does not have extended functions\n");
> -				return -1;
> +				return CMD_RET_FAILURE;
> +			}
> +		}
> +		if (op[1] == 'm') {
> +			phydev = mdio_phydev_for_ethname(argv[2]);
> +
> +			if (phydev) {
> +				addrlo = phydev->addr;
> +				addrhi = addrlo;
> +				bus = phydev->bus;
> +				mmd = 1;
> +			} else {
> +				return CMD_RET_FAILURE;
>   			}
>   		}
>   	}
> @@ -242,13 +260,13 @@ static int do_mdio(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
>   		if (pos > 1)
>   			if (extract_reg_range(argv[pos--], &devadlo, &devadhi,
>   					      &reglo, &reghi))
> -				return -1;
> +				return CMD_RET_FAILURE;
>   
>   	default:
>   		if (pos > 1)
>   			if (extract_phy_range(&argv[2], pos - 1, &bus,
>   					      &phydev, &addrlo, &addrhi))
> -				return -1;
> +				return CMD_RET_FAILURE;
>   
>   		break;
>   	}
> @@ -265,12 +283,12 @@ static int do_mdio(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
>   	switch (op[0]) {
>   	case 'w':
>   		mdio_write_ranges(phydev, bus, addrlo, addrhi, devadlo, devadhi,
> -				  reglo, reghi, data, extended);
> +				  reglo, reghi, data, extended, mmd);
>   		break;
>   
>   	case 'r':
>   		mdio_read_ranges(phydev, bus, addrlo, addrhi, devadlo, devadhi,
> -				 reglo, reghi, extended);
> +				 reglo, reghi, extended, mmd);
>   		break;
>   	}
>   
> @@ -303,6 +321,10 @@ U_BOOT_CMD(
>   		"read PHY's extended register at <devad>.<reg>\n"
>   	"mdio wx <phydev> [<devad>.]<reg> <data> - "
>   		"write PHY's extended register at <devad>.<reg>\n"
> +	"mdio rmmd <phydev> [<devad>.]<reg> - "
> +		"read PHY's extended register at <devad>.<reg>\n"
> +	"mdio wmmd <phydev> [<devad>.]<reg> <data> - "
> +		"write PHY's extended register at <devad>.<reg>\n"
>   	"<phydev> may be:\n"
>   	"   <busname>  <addr>\n"
>   	"   <addr>\n"
> 

It works for me, but I do have a question.
Is there any limitation preventing you to add this functionality via the 
standard "mdio read x.y" instead of "mdio rmmd x.y" if the PHY is known 
to be C22?

-Vladimir