Re: [PATCH v1 7/8] drm: rcar-du: dsi: Add r8A779g0 support

From: Laurent Pinchart
Date: Mon Nov 28 2022 - 19:44:20 EST

On Tue, Nov 22, 2022 at 10:50:30AM +0200, Tomi Valkeinen wrote:
> On 17/11/2022 17:46, Kieran Bingham wrote:
> > Quoting Tomi Valkeinen (2022-11-17 12:25:46)
> >> From: Tomi Valkeinen <tomi.valkeinen+renesas@xxxxxxxxxxxxxxxx>
> >>
> >> Add DSI support for r8a779g0. The main differences to r8a779a0 are in
> >> the PLL and PHTW setups.
> >>
> >> Signed-off-by: Tomi Valkeinen <tomi.valkeinen+renesas@xxxxxxxxxxxxxxxx>
> >> ---
> >> drivers/gpu/drm/rcar-du/rcar_mipi_dsi.c | 484 +++++++++++++++----
> >> drivers/gpu/drm/rcar-du/rcar_mipi_dsi_regs.h | 6 +-
> >> 2 files changed, 384 insertions(+), 106 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/rcar-du/rcar_mipi_dsi.c b/drivers/gpu/drm/rcar-du/rcar_mipi_dsi.c
> >> index a7f2b7f66a17..723c35726c38 100644
> >> --- a/drivers/gpu/drm/rcar-du/rcar_mipi_dsi.c
> >> +++ b/drivers/gpu/drm/rcar-du/rcar_mipi_dsi.c
> >> @@ -9,6 +9,7 @@
> >> #include <linux/delay.h>
> >> #include <linux/io.h>
> >> #include <linux/iopoll.h>
> >> +#include <linux/math64.h>
> >> #include <linux/module.h>
> >> #include <linux/of.h>
> >> #include <linux/of_device.h>
> >> @@ -28,6 +29,20 @@
> >> #include "rcar_mipi_dsi.h"
> >> #include "rcar_mipi_dsi_regs.h"
> >>
> >> +#define MHZ(v) ((v) * 1000000u)
> >> +
> >> +enum rcar_mipi_dsi_hw_model {
> >> + RCAR_DSI_R8A779A0,
> >> + RCAR_DSI_R8A779G0,
> >> +};
> >> +
> >> +struct rcar_mipi_dsi_device_info {
> >> + enum rcar_mipi_dsi_hw_model model;
> >> + const struct dsi_clk_config *clk_cfg;
> >> + u8 clockset2_m_offset;
> >> + u8 clockset2_n_offset;
> >> +};
> >> +
> >> struct rcar_mipi_dsi {
> >> struct device *dev;
> >> const struct rcar_mipi_dsi_device_info *info;
> >> @@ -50,6 +65,17 @@ struct rcar_mipi_dsi {
> >> unsigned int lanes;
> >> };
> >>
> >> +struct dsi_setup_info {
> >> + unsigned long hsfreq;
> >> + u16 hsfreqrange;
> >> +
> >> + unsigned long fout;
> >> + u16 m;
> >> + u16 n;
> >> + u16 vclk_divider;
> >> + const struct dsi_clk_config *clkset;
> >> +};
> >> +
> >> static inline struct rcar_mipi_dsi *
> >> bridge_to_rcar_mipi_dsi(struct drm_bridge *bridge)
> >> {
> >> @@ -62,22 +88,6 @@ host_to_rcar_mipi_dsi(struct mipi_dsi_host *host)
> >> return container_of(host, struct rcar_mipi_dsi, host);
> >> }
> >>
> >> -static const u32 phtw[] = {
> >> - 0x01020114, 0x01600115, /* General testing */
> >> - 0x01030116, 0x0102011d, /* General testing */
> >> - 0x011101a4, 0x018601a4, /* 1Gbps testing */
> >> - 0x014201a0, 0x010001a3, /* 1Gbps testing */
> >> - 0x0101011f, /* 1Gbps testing */
> >> -};
> >> -
> >> -static const u32 phtw2[] = {
> >> - 0x010c0130, 0x010c0140, /* General testing */
> >> - 0x010c0150, 0x010c0180, /* General testing */
> >> - 0x010c0190,
> >> - 0x010a0160, 0x010a0170,
> >> - 0x01800164, 0x01800174, /* 1Gbps testing */
> >> -};
> >> -
> >> static const u32 hsfreqrange_table[][2] = {
> >> { 80000000U, 0x00 }, { 90000000U, 0x10 }, { 100000000U, 0x20 },
> >> { 110000000U, 0x30 }, { 120000000U, 0x01 }, { 130000000U, 0x11 },
> >> @@ -103,24 +113,53 @@ static const u32 hsfreqrange_table[][2] = {
> >> { /* sentinel */ },
> >> };
> >>
> >> -struct vco_cntrl_value {
> >> +struct dsi_clk_config {
> >> u32 min_freq;
> >> u32 max_freq;
> >> - u16 value;
> >> + u8 vco_cntrl;
> >> + u8 cpbias_cntrl;
> >> + u8 gmp_cntrl;
> >> + u8 int_cntrl;
> >> + u8 prop_cntrl;
> >> };
> >>
> >> -static const struct vco_cntrl_value vco_cntrl_table[] = {
> >> - { .min_freq = 40000000U, .max_freq = 55000000U, .value = 0x3f },
> >> - { .min_freq = 52500000U, .max_freq = 80000000U, .value = 0x39 },
> >> - { .min_freq = 80000000U, .max_freq = 110000000U, .value = 0x2f },
> >> - { .min_freq = 105000000U, .max_freq = 160000000U, .value = 0x29 },
> >> - { .min_freq = 160000000U, .max_freq = 220000000U, .value = 0x1f },
> >> - { .min_freq = 210000000U, .max_freq = 320000000U, .value = 0x19 },
> >> - { .min_freq = 320000000U, .max_freq = 440000000U, .value = 0x0f },
> >> - { .min_freq = 420000000U, .max_freq = 660000000U, .value = 0x09 },
> >> - { .min_freq = 630000000U, .max_freq = 1149000000U, .value = 0x03 },
> >> - { .min_freq = 1100000000U, .max_freq = 1152000000U, .value = 0x01 },
> >> - { .min_freq = 1150000000U, .max_freq = 1250000000U, .value = 0x01 },
> >> +static const struct dsi_clk_config dsi_clk_cfg_r8a779a0[] = {
> >> + { 40000000u, 55000000u, 0x3f, 0x10, 0x01, 0x00, 0x0b },
> >> + { 52500000u, 80000000u, 0x39, 0x10, 0x01, 0x00, 0x0b },
> >> + { 80000000u, 110000000u, 0x2f, 0x10, 0x01, 0x00, 0x0b },
> >> + { 105000000u, 160000000u, 0x29, 0x10, 0x01, 0x00, 0x0b },
> >> + { 160000000u, 220000000u, 0x1f, 0x10, 0x01, 0x00, 0x0b },
> >> + { 210000000u, 320000000u, 0x19, 0x10, 0x01, 0x00, 0x0b },
> >> + { 320000000u, 440000000u, 0x0f, 0x10, 0x01, 0x00, 0x0b },
> >> + { 420000000u, 660000000u, 0x09, 0x10, 0x01, 0x00, 0x0b },
> >> + { 630000000u, 1149000000u, 0x03, 0x10, 0x01, 0x00, 0x0b },
> >> + { 1100000000u, 1152000000u, 0x01, 0x10, 0x01, 0x00, 0x0b },
> >> + { 1150000000u, 1250000000u, 0x01, 0x10, 0x01, 0x00, 0x0c },
> >
> > Sigh ... is it this one 0x0c value that means we need to keep all these
> > entries repeated ? :-S
> >
> > If it weren't for that, it seems we could keep just two sets of
> >> + u8 cpbias_cntrl;
> >> + u8 gmp_cntrl;
> >> + u8 int_cntrl;
> >> + u8 prop_cntrl;
> >
> > One for each of the 9a0, and the 9g0...
> >
> > But this is fine, and I guess the implication is there may be other
> > future differences to come in other platforms.
> >
> > It could be refactored then when we have more visibility.
>
> Yes, it's not so nice. And afaiu some of these values should really be
> solved dynamically in the code. But the docs list these tables and don't
> explain how to come up with those values, so... I think having these
> tables is the safest way.

We could drop the cpbias_cntrl, gmp_cntrl and int_cntrl fields and set
them based on the IP version.

> >> @@ -427,8 +671,21 @@ static int rcar_mipi_dsi_startup(struct rcar_mipi_dsi *dsi,
> >> dev_warn(dsi->dev, "unsupported format");
> >> return -EINVAL;
> >> }
> >> - vclkset |= VCLKSET_COLOR_RGB | VCLKSET_DIV(setup_info.div)
> >> - | VCLKSET_LANE(dsi->lanes - 1);
> >> +
> >> + vclkset |= VCLKSET_COLOR_RGB | VCLKSET_LANE(dsi->lanes - 1);
> >> +
> >> + switch (dsi->info->model) {
> >> + case RCAR_DSI_R8A779A0:
> >> + vclkset |= VCLKSET_DIV_R8A779A0(__ffs(setup_info.vclk_divider));
> >> + break;
> >> +
> >> + case RCAR_DSI_R8A779G0:
> >> + vclkset |= VCLKSET_DIV_R8A779G0(__ffs(setup_info.vclk_divider) - 1);
> >
> > Why is this a -1 here ? Seems an odd difference compared to the A0.
>
> You need to ask the HW designers =). That's how the register is on G0.
> Field value of 0 means divided by 2.

--
Regards,

Laurent Pinchart