Messages in this thread | | | Date | Tue, 28 Mar 2023 15:59:17 +0200 | From | Andrew Lunn <> | Subject | Re: [RFC PATCH net-next 2/2] net: dsa: mt7530: introduce MMIO driver for MT7988 SoC |
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> I agree that using regmap would be better and I have evaluated that > approach as well. As regmap doesn't allow lock-skipping and mt7530.c is > much more complex than xrs700x in the way indirect access to its MDIO bus > and interrupts work, using regmap accessors for everything would not be > trivial.
O.K, so lets go another way.
Study the low level accesors, and put an abstraction over them. Provide an MDIO set and an MMIO set.
> To illustrate what I'm talking about, let me show some examples in the > current code for which I don't see a way to use regmap: > 634) static int > 635) mt7531_ind_c45_phy_read(struct mt7530_priv *priv, int port, int devad, > 636) int regnum) > 637) { > 638) struct mii_bus *bus = priv->bus; > 639) struct mt7530_dummy_poll p; > 640) u32 reg, val; > 641) int ret; > 642) > 643) INIT_MT7530_DUMMY_POLL(&p, priv, MT7531_PHY_IAC); > 644) > 645) mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
So you need an abstract lock() and an unlock(). Maybe the MMIO implementation is a NOP? And the MDIO implementation does a real lock?
> 646) > 647) ret = readx_poll_timeout(_mt7530_unlocked_read, &p, val, > 648) !(val & MT7531_PHY_ACS_ST), 20, 100000);
_mt7530_unlocked_read and presumably _mt7530_unlocked_write()?
> 649) if (ret < 0) { > 650) dev_err(priv->dev, "poll timeout\n"); > 651) goto out; > 652) } > 653) > 654) reg = MT7531_MDIO_CL45_ADDR | MT7531_MDIO_PHY_ADDR(port) | > 655) MT7531_MDIO_DEV_ADDR(devad) | regnum; > 656) mt7530_mii_write(priv, MT7531_PHY_IAC, reg | MT7531_PHY_ACS_ST);
mt7530_write() and mt7530_read()
Put the MDIO accessors in the _mdio.c file, and the MMIO accessors in the _mmio.c file. Pass them to the core. If you have the abstraction correct, the core should not care how the registers are accessed.
Andrew
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