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SubjectRe: [PATCH 03/10] phy: Add MIPI D-PHY configuration options
Date
Hi Maxime,

Thank you for the patch.

On Wednesday, 5 September 2018 12:16:34 EEST Maxime Ripard wrote:
> Now that we have some infrastructure for it, allow the MIPI D-PHY phy's to
> be configured through the generic functions through a custom structure
> added to the generic union.
>
> The parameters added here are the one defined in the MIPI D-PHY spec, plus

s/one/ones/

> some parameters that were used by a number of PHY drivers currently found
> in the linux kernel.

It would be useful to document which parameters are from the spec and which
are not.

> The current set of parameters should cover all the potential users.
>
> Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
> ---
> include/linux/phy/phy-mipi-dphy.h | 241 +++++++++++++++++++++++++++++++-
> include/linux/phy/phy.h | 6 +-
> 2 files changed, 247 insertions(+)
> create mode 100644 include/linux/phy/phy-mipi-dphy.h
>
> diff --git a/include/linux/phy/phy-mipi-dphy.h
> b/include/linux/phy/phy-mipi-dphy.h new file mode 100644
> index 000000000000..792724145290
> --- /dev/null
> +++ b/include/linux/phy/phy-mipi-dphy.h
> @@ -0,0 +1,241 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2018 Cadence Design Systems Inc.
> + */
> +
> +#ifndef __PHY_MIPI_DPHY_H_
> +#define __PHY_MIPI_DPHY_H_
> +
> +#include <video/videomode.h>
> +
> +/**
> + * struct phy_configure_opts_mipi_dphy - MIPI D-PHY configuration set
> + *
> + * This structure is used to represent the configuration state of a
> + * MIPI D-PHY phy.

Shouldn't we split the RX and TX parameters in two structures ?

> + */
> +struct phy_configure_opts_mipi_dphy {
> + /**
> + * @clk_miss:
> + *
> + * Timeout, in nanoseconds, for receiver to detect absence of
> + * Clock transitions and disable the Clock Lane HS-RX.
> + */
> + unsigned int clk_miss;
> +
> + /**
> + * @clk_post:
> + *
> + * Time, in nanoseconds, that the transmitter continues to
> + * send HS clock after the last associated Data Lane has
> + * transitioned to LP Mode. Interval is defined as the period
> + * from the end of @hs_trail to the beginning of @clk_trail.
> + */
> + unsigned int clk_post;
> +
> + /**
> + * @clk_pre:
> + *
> + * Time, in nanoseconds, that the HS clock shall be driven by
> + * the transmitter prior to any associated Data Lane beginning
> + * the transition from LP to HS mode.
> + */
> + unsigned int clk_pre;
> +
> + /**
> + * @clk_prepare:
> + *
> + * Time, in nanoseconds, that the transmitter drives the Clock
> + * Lane LP-00 Line state immediately before the HS-0 Line
> + * state starting the HS transmission.
> + */
> + unsigned int clk_prepare;
> +
> + /**
> + * @clk_settle:
> + *
> + * Time interval, in nanoseconds, during which the HS receiver
> + * should ignore any Clock Lane HS transitions, starting from
> + * the beginning of @clk_prepare.
> + */
> + unsigned int clk_settle;
> +
> + /**
> + * @clk_term_en:
> + *
> + * Time, in nanoseconds, for the Clock Lane receiver to enable
> + * the HS line termination.
> + */
> + unsigned int clk_term_en;
> +
> + /**
> + * @clk_trail:
> + *
> + * Time, in nanoseconds, that the transmitter drives the HS-0
> + * state after the last payload clock bit of a HS transmission
> + * burst.
> + */
> + unsigned int clk_trail;
> +
> + /**
> + * @clk_zero:
> + *
> + * Time, in nanoseconds, that the transmitter drives the HS-0
> + * state prior to starting the Clock.
> + */
> + unsigned int clk_zero;
> +
> + /**
> + * @d_term_en:
> + *
> + * Time, in nanoseconds, for the Data Lane receiver to enable
> + * the HS line termination.
> + */
> + unsigned int d_term_en;
> +
> + /**
> + * @eot:
> + *
> + * Transmitted time interval, in nanoseconds, from the start
> + * of @hs_trail or @clk_trail, to the start of the LP- 11
> + * state following a HS burst.
> + */
> + unsigned int eot;
> +
> + /**
> + * @hs_exit:
> + *
> + * Time, in nanoseconds, that the transmitter drives LP-11
> + * following a HS burst.
> + */
> + unsigned int hs_exit;
> +
> + /**
> + * @hs_prepare:
> + *
> + * Time, in nanoseconds, that the transmitter drives the Data
> + * Lane LP-00 Line state immediately before the HS-0 Line
> + * state starting the HS transmission
> + */
> + unsigned int hs_prepare;
> +
> + /**
> + * @hs_settle:
> + *
> + * Time interval, in nanoseconds, during which the HS receiver
> + * shall ignore any Data Lane HS transitions, starting from
> + * the beginning of @hs_prepare.
> + */
> + unsigned int hs_settle;
> +
> + /**
> + * @hs_skip:
> + *
> + * Time interval, in nanoseconds, during which the HS-RX
> + * should ignore any transitions on the Data Lane, following a
> + * HS burst. The end point of the interval is defined as the
> + * beginning of the LP-11 state following the HS burst.
> + */
> + unsigned int hs_skip;
> +
> + /**
> + * @hs_trail:
> + *
> + * Time, in nanoseconds, that the transmitter drives the
> + * flipped differential state after last payload data bit of a
> + * HS transmission burst
> + */
> + unsigned int hs_trail;
> +
> + /**
> + * @hs_zero:
> + *
> + * Time, in nanoseconds, that the transmitter drives the HS-0
> + * state prior to transmitting the Sync sequence.
> + */
> + unsigned int hs_zero;
> +
> + /**
> + * @lpx:
> + *
> + * Transmitted length, in nanoseconds, of any Low-Power state
> + * period.
> + */
> + unsigned int lpx;
> +
> + /**
> + * @ta_get:
> + *
> + * Time, in nanoseconds, that the new transmitter drives the
> + * Bridge state (LP-00) after accepting control during a Link
> + * Turnaround.
> + */
> + unsigned int ta_get;
> +
> + /**
> + * @ta_go:
> + *
> + * Time, in nanoseconds, that the transmitter drives the
> + * Bridge state (LP-00) before releasing control during a Link
> + * Turnaround.
> + */
> + unsigned int ta_go;
> +
> + /**
> + * @ta_sure:
> + *
> + * Time, in nanoseconds, that the new transmitter waits after
> + * the LP-10 state before transmitting the Bridge state
> + * (LP-00) during a Link Turnaround.
> + */
> + unsigned int ta_sure;
> +
> + /**
> + * @wakeup:
> + *
> + * Time, in nanoseconds, that a transmitter drives a Mark-1
> + * state prior to a Stop state in order to initiate an exit
> + * from ULPS.
> + */
> + unsigned int wakeup;
> +
> + /**
> + * @hs_clk_rate:
> + *
> + * Clock rate, in Hertz, of the high-speed clock.
> + */
> + unsigned long hs_clk_rate;
> +
> + /**
> + * @lp_clk_rate:
> + *
> + * Clock rate, in Hertz, of the low-power clock.
> + */
> + unsigned long lp_clk_rate;
> +
> + /**
> + * @lanes:
> + *
> + * Number of lanes used for the transmissions.
> + */
> + unsigned char lanes;
> +
> + /**
> + * @modes:
> + *
> + * transmission operation mode flags
> + */
> + u32 modes;

Where are those flags defined ?

> + /**
> + * @timings:
> + *
> + * Video timings associated with the transmission.

That's a pretty vague description...

> + */
> + struct videomode timings;
> +};
> +
> +/* TODO: Add other modes (burst, commands, etc) */
> +#define MIPI_DPHY_MODE_VIDEO_SYNC_PULSE BIT(0)
> +
> +#endif /* __PHY_MIPI_DPHY_H_ */
> diff --git a/include/linux/phy/phy.h b/include/linux/phy/phy.h
> index 3cc315dcfcd0..2b7a72f98428 100644
> --- a/include/linux/phy/phy.h
> +++ b/include/linux/phy/phy.h
> @@ -20,6 +20,8 @@
> #include <linux/pm_runtime.h>
> #include <linux/regulator/consumer.h>
>
> +#include <linux/phy/phy-mipi-dphy.h>

You can move this within the existing list of #include's.

> +
> struct phy;
>
> enum phy_mode {
> @@ -45,8 +47,12 @@ enum phy_mode {
>
> /**
> * union phy_configure_opts - Opaque generic phy configuration
> + *
> + * @mipi_dphy: Configuration set applicable for phys supporting
> + * the MIPI_DPHY phy mode.
> */
> union phy_configure_opts {
> + struct phy_configure_opts_mipi_dphy mipi_dphy;
> };
>
> /**

--
Regards,

Laurent Pinchart



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