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Date:   Mon, 27 Nov 2023 14:37:41 +0100
From:   Andrew Lunn <andrew@lunn.ch>
To:     =?iso-8859-1?Q?Ram=F3n_N=2ERodriguez?= 
        <ramon.nordin.rodriguez@ferroamp.se>
Cc:     Heiner Kallweit <hkallweit1@gmail.com>,
        Russell King <linux@armlinux.org.uk>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/3] net: microchip_t1s: add support for LAN867x Rev.C1
Message-ID: <f25ed798-e116-4f6f-ad3c-5060c7d540d0@lunn.ch>
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 <20231127104045.96722-3-ramon.nordin.rodriguez@ferroamp.se>
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>  #define PHY_ID_LAN867X_REVB1 0x0007C162
> +#define PHY_ID_LAN867X_REVC1 0x0007C164

So there is a gap in the revisions. Maybe a B2 exists?

> +static int lan867x_revc1_read_fixup_value(struct phy_device *phydev, u16 addr)
> +{
> +	int regval;
> +	/* The AN pretty much just states 'trust us' regarding these magic vals */
> +	const u16 magic_or = 0xE0;
> +	const u16 magic_reg_mask = 0x1F;
> +	const u16 magic_check_mask = 0x10;

Reverse christmass tree please. Longest first, shorted last.

> +	regval = lan865x_revb0_indirect_read(phydev, addr);
> +	if (regval < 0)
> +		return regval;
> +
> +	regval &= magic_reg_mask;
> +
> +	return (regval & magic_check_mask) ? regval | magic_or : regval;
> +}
> +
> +static int lan867x_revc1_config_init(struct phy_device *phydev)
> +{
> +	int err;
> +	int regval;
> +	u16 override0;
> +	u16 override1;
> +	const u16 override_addr0 = 0x4;
> +	const u16 override_addr1 = 0x8;
> +	const u8 index_to_override0 = 2;
> +	const u8 index_to_override1 = 3;

Same here.

> +
> +	err = lan867x_wait_for_reset_complete(phydev);
> +	if (err)
> +		return err;
> +
> +	/* The application note specifies a super convenient process
> +	 * where 2 of the fixup regs needs a write with a value that is
> +	 * a modified result of another reg read.
> +	 * Enjoy the magic show.
> +	 */

I really do hope that by revision D1 they get the firmware sorted out
so none of this undocumented magic is needed.

	Andrew