Re: [PATCH 6.1.y-cip 20/25] drm: renesas: rz-du: mipi_dsi: Add support for RZ/V2H(P) SoC

[Pavel Machek <pavel@nabladev.com>]

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Hi!

> Add MIPI DSI support for the Renesas RZ/V2H(P) SoC. Compared to the
> RZ/G2L family, the RZ/V2H(P) requires dedicated D-PHY PLL programming,
> different clock configuration, and additional timing parameter handling.
> The driver introduces lookup tables and helpers for D-PHY timings
> (TCLK*, THS*, TLPX, and ULPS exit) as specified in the RZ/V2H(P) hardware
> manual. ULPS exit timing depends on the LPCLK rate and is now handled
> explicitly.
> 
> The implementation also adds support for 16 bpp RGB format, updates the
> clock setup path to use the RZ/V2H PLL divider limits, and provides new
> .dphy_init, .dphy_conf_clks, and .dphy_startup_late_init callbacks to
> match the RZ/V2H sequence.
> 
> With these changes, the RZ/V2H(P) can operate the MIPI DSI interface in
> compliance with its hardware specification while retaining support for
> existing RZ/G2L platforms.

> +++ b/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c


> +static const u8 thsexitctl[] = {
> +	15, 23, 31, 39, 47, 55, 63, 71, 79, 87,
> +	95, 103, 111, 119, 127, 135, 143, 150,
> +};

Some _'s in the control names would make these more clear. I believe
it is ths_exit_ctl, but... there are more confusing ways to parse this.

> +/**
> + * rzv2h_dphy_find_timings_val - Find timing parameter value from lookup tables
> + * @freq: Input frequency in Hz
> + * @index: Index to select timing parameter table (see enum rzv2h_dsi_timing_idx)
> + *
> + * Selects the timing table for the requested parameter, finds the
> + * frequency range entry and returns the register value to program:
> + *
> + *   register_value = timings->base_value + table_index
> + *
> + * Note: frequency table entries are stored as small integers (units of 10):

This should probably say "units of of 10MHz", if I'm reading that correctly.

> +
> +static const u8 rzv2h_cpg_div_table[] = {
> +	2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32,
> +};

Ok, so this is table of even numbers. Other tables seem to have kind
of regular, too. Documenting how the tables were created would not be
bad.

Thanks and best regards,
								Pavel

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