diff mbox series

[v2,10/15] drm: renesas: rz-du: mipi_dsi: Use mHz for D-PHY frequency calculations

Message ID 20250408200916.93793-11-prabhakar.mahadev-lad.rj@bp.renesas.com (mailing list archive)
State New
Delegated to: Kieran Bingham
Headers show
Series Add support for DU and DSI on the Renesas RZ/V2H(P) SoC | expand

Commit Message

Lad, Prabhakar April 8, 2025, 8:09 p.m. UTC 
From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

Pass the HSFREQ in milli-Hz to the `dphy_init()` callback to improve
precision, especially for the RZ/V2H(P) SoC, where PLL dividers require
high accuracy.

These changes prepare the driver for upcoming RZ/V2H(P) SoC support.

Co-developed-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
Signed-off-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
---
v1->v2:
- No changes
---
 drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

Comments

Geert Uytterhoeven April 9, 2025, 8:15 a.m. UTC | #1 
Hi Prabhakar,

On Tue, 8 Apr 2025 at 22:09, Prabhakar <prabhakar.csengg@gmail.com> wrote:
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
>
> Pass the HSFREQ in milli-Hz to the `dphy_init()` callback to improve
> precision, especially for the RZ/V2H(P) SoC, where PLL dividers require
> high accuracy.
>
> These changes prepare the driver for upcoming RZ/V2H(P) SoC support.
>
> Co-developed-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
> Signed-off-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

Thanks for your patch!

> --- a/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c
> +++ b/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c
> @@ -33,7 +33,7 @@
>  struct rzg2l_mipi_dsi;
>
>  struct rzg2l_mipi_dsi_hw_info {
> -       int (*dphy_init)(struct rzg2l_mipi_dsi *dsi, unsigned long hsfreq);
> +       int (*dphy_init)(struct rzg2l_mipi_dsi *dsi, unsigned long long hsfreq_mhz);

Due to the lack of capitalization of the "hz" part, it is not clear
that the "m" stands for "milli" instead of "mega".
Perhaps hsfreq_mHz or hsfreq_millihz?

Gr{oetje,eeting}s,

                        Geert
Lad, Prabhakar April 9, 2025, 8:55 a.m. UTC | #2 
Hi Geert,

Thank you for the review.

On Wed, Apr 9, 2025 at 9:16 AM Geert Uytterhoeven <geert@linux-m68k.org> wrote:
>
> Hi Prabhakar,
>
> On Tue, 8 Apr 2025 at 22:09, Prabhakar <prabhakar.csengg@gmail.com> wrote:
> > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> >
> > Pass the HSFREQ in milli-Hz to the `dphy_init()` callback to improve
> > precision, especially for the RZ/V2H(P) SoC, where PLL dividers require
> > high accuracy.
> >
> > These changes prepare the driver for upcoming RZ/V2H(P) SoC support.
> >
> > Co-developed-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
> > Signed-off-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
> > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
>
> Thanks for your patch!
>
> > --- a/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c
> > +++ b/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c
> > @@ -33,7 +33,7 @@
> >  struct rzg2l_mipi_dsi;
> >
> >  struct rzg2l_mipi_dsi_hw_info {
> > -       int (*dphy_init)(struct rzg2l_mipi_dsi *dsi, unsigned long hsfreq);
> > +       int (*dphy_init)(struct rzg2l_mipi_dsi *dsi, unsigned long long hsfreq_mhz);
>
> Due to the lack of capitalization of the "hz" part, it is not clear
> that the "m" stands for "milli" instead of "mega".
> Perhaps hsfreq_mHz or hsfreq_millihz?
>
Agreed, I will use `hsfreq_millihz`. Shall I respin a new version as
the initial patches do the same (i.e. use mhz).

Cheers,
Prabhakar
diff mbox series

Patch

diff --git a/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c b/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c
index 07457a57cf3b..4a8fe52e9752 100644
--- a/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c
+++ b/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c
@@ -33,7 +33,7 @@ 
 struct rzg2l_mipi_dsi;
 
 struct rzg2l_mipi_dsi_hw_info {
-	int (*dphy_init)(struct rzg2l_mipi_dsi *dsi, unsigned long hsfreq);
+	int (*dphy_init)(struct rzg2l_mipi_dsi *dsi, unsigned long long hsfreq_mhz);
 	void (*dphy_exit)(struct rzg2l_mipi_dsi *dsi);
 	u32 phy_reg_offset;
 	u32 link_reg_offset;
@@ -203,8 +203,9 @@  static u32 rzg2l_mipi_dsi_link_read(struct rzg2l_mipi_dsi *dsi, u32 reg)
  */
 
 static int rzg2l_mipi_dsi_dphy_init(struct rzg2l_mipi_dsi *dsi,
-				    unsigned long hsfreq)
+				    unsigned long long hsfreq_mhz)
 {
+	unsigned long hsfreq = DIV_ROUND_CLOSEST_ULL(hsfreq_mhz, KILO);
 	const struct rzg2l_mipi_dsi_timings *dphy_timings;
 	unsigned int i;
 	u32 dphyctrl0;
@@ -277,6 +278,7 @@  static int rzg2l_mipi_dsi_startup(struct rzg2l_mipi_dsi *dsi,
 				  const struct drm_display_mode *mode)
 {
 	unsigned long hsfreq, vclk_rate;
+	unsigned long long hsfreq_mhz;
 	unsigned int bpp;
 	u32 txsetr;
 	u32 clstptsetr;
@@ -305,9 +307,9 @@  static int rzg2l_mipi_dsi_startup(struct rzg2l_mipi_dsi *dsi,
 	 */
 	bpp = mipi_dsi_pixel_format_to_bpp(dsi->format);
 	vclk_rate = clk_get_rate(dsi->vclk);
-	hsfreq = DIV_ROUND_CLOSEST_ULL(vclk_rate * bpp, dsi->lanes);
+	hsfreq_mhz = DIV_ROUND_CLOSEST_ULL(vclk_rate * bpp * KILO * 1ULL, dsi->lanes);
 
-	ret = dsi->info->dphy_init(dsi, hsfreq);
+	ret = dsi->info->dphy_init(dsi, hsfreq_mhz);
 	if (ret < 0)
 		goto err_phy;
 
@@ -315,6 +317,7 @@  static int rzg2l_mipi_dsi_startup(struct rzg2l_mipi_dsi *dsi,
 	txsetr = TXSETR_DLEN | TXSETR_NUMLANEUSE(dsi->lanes - 1) | TXSETR_CLEN;
 	rzg2l_mipi_dsi_link_write(dsi, TXSETR, txsetr);
 
+	hsfreq = DIV_ROUND_CLOSEST_ULL(hsfreq_mhz, KILO);
 	/*
 	 * Global timings characteristic depends on high speed Clock Frequency
 	 * Currently MIPI DSI-IF just supports maximum FHD@60 with:
@@ -781,7 +784,7 @@  static int rzg2l_mipi_dsi_probe(struct platform_device *pdev)
 	 * mode->clock and format are not available. So initialize DPHY with
 	 * timing parameters for 80Mbps.
 	 */
-	ret = dsi->info->dphy_init(dsi, 80000000);
+	ret = dsi->info->dphy_init(dsi, 80000000ULL * KILO);
 	if (ret < 0)
 		goto err_phy;