[PATCH 3/5] net: phy: Add phy_read_mmd_poll_timeout() from Linux

[Ramon Fried]

On Sun, Mar 19, 2023 at 7:08 PM Marek Vasut
<marek.vasut+renesas at mailbox.org> wrote:
>
> Add phy_read_mmd_poll_timeout() from Linux 5.7.y as of commit
> bd971ff0b7392 ("net: phy: introduce phy_read_mmd_poll_timeout macro")
> This is used by the upcoming Marvell 10G PHY driver.
>
> Signed-off-by: Marek Vasut <marek.vasut+renesas at mailbox.org>
> ---
> Cc: "Ariel D'Alessandro" <ariel.dalessandro at collabora.com>
> Cc: "Marek Behún" <kabel at kernel.org>
> Cc: Joe Hershberger <joe.hershberger at ni.com>
> Cc: Marek Vasut <marek.vasut+renesas at mailbox.org>
> Cc: Michael Trimarchi <michael at amarulasolutions.com>
> Cc: Nate Drude <nate.d at variscite.com>
> Cc: Ramon Fried <rfried.dev at gmail.com>
> Cc: Simon Glass <sjg at chromium.org>
> Cc: Stefan Roese <sr at denx.de>
> Cc: Tim Harvey <tharvey at gateworks.com>
> Cc: Vladimir Oltean <vladimir.oltean at nxp.com>
> ---
>  include/phy.h | 31 +++++++++++++++++++++++++++++++
>  1 file changed, 31 insertions(+)
>
> diff --git a/include/phy.h b/include/phy.h
> index 34675b2c9c0..a837fed7235 100644
> --- a/include/phy.h
> +++ b/include/phy.h
> @@ -282,6 +282,37 @@ static inline ofnode phy_get_ofnode(struct phy_device *phydev)
>                 return dev_ofnode(phydev->dev);
>  }
>
> +/**
> + * phy_read_mmd_poll_timeout - Periodically poll a PHY register until a
> + *                             condition is met or a timeout occurs
> + *
> + * @phydev: The phy_device struct
> + * @devaddr: The MMD to read from
> + * @regnum: The register on the MMD to read
> + * @val: Variable to read the register into
> + * @cond: Break condition (usually involving @val)
> + * @sleep_us: Maximum time to sleep between reads in us (0
> + *            tight-loops).  Should be less than ~20ms since usleep_range
> + *            is used (see Documentation/timers/timers-howto.rst).
> + * @timeout_us: Timeout in us, 0 means never timeout
> + * @sleep_before_read: if it is true, sleep @sleep_us before read.
> + * Returns 0 on success and -ETIMEDOUT upon a timeout. In either
> + * case, the last read value at @args is stored in @val. Must not
> + * be called from atomic context if sleep_us or timeout_us are used.
> + */
> +#define phy_read_mmd_poll_timeout(phydev, devaddr, regnum, val, cond, \
> +                                 sleep_us, timeout_us, sleep_before_read) \
> +({ \
> +       int __ret = read_poll_timeout(phy_read_mmd, val, (cond) || val < 0, \
> +                                 sleep_us, timeout_us, \
> +                                 phydev, devaddr, regnum); \
> +       if (val <  0) \
> +               __ret = val; \
> +       if (__ret) \
> +               dev_err(phydev->dev, "%s failed: %d\n", __func__, __ret); \
> +       __ret; \
> +})
> +
>  int phy_read(struct phy_device *phydev, int devad, int regnum);
>  int phy_write(struct phy_device *phydev, int devad, int regnum, u16 val);
>  void phy_mmd_start_indirect(struct phy_device *phydev, int devad, int regnum);
> --
> 2.39.2
>
Reviewed-by: Ramon Fried <rfried.dev at gmail.com>