[RESEND PATCH 0/3] imx6: clock: add support to get LCD pixel clock rate

[RESEND PATCH 0/3] imx6: clock: add support to get LCD pixel clock rate

[Dario Binacchi]

The series adds a function to get the LCD pixel clock rate. Also
improves video PLLL rate calculation.


Dario Binacchi (3):
  imx6: clock: improve calculations to get the PLL video rate
  imx6: clock: add support to get LCD pixel clock rate
  imx6: clock: print real pixel clock rate

 arch/arm/include/asm/arch-mx6/clock.h |  2 +
 arch/arm/mach-imx/mx6/clock.c         | 66 ++++++++++++++++++++++++++-
 2 files changed, 67 insertions(+), 1 deletion(-)

-- 
2.32.0

[RESEND PATCH 1/3] imx6: clock: improve calculations to get the PLL video rate

[Dario Binacchi]

During some tests to check the pixel clock rate in the transition from
U-Boot to the Linux kernel, I noticed that with the same configuration
of the registers the debug messages reported different rates.

The same Linux kernel calculations are now used to get the PLL video
rate.

Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Reviewed-by: Michael Trimarchi <michael@amarulasolutions.com>
---

 arch/arm/mach-imx/mx6/clock.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-imx/mx6/clock.c b/arch/arm/mach-imx/mx6/clock.c
index cb9d629be408..17d8dcd5c841 100644
--- a/arch/arm/mach-imx/mx6/clock.c
+++ b/arch/arm/mach-imx/mx6/clock.c
@@ -213,6 +213,7 @@ int enable_spi_clk(unsigned char enable, unsigned spi_num)
 static u32 decode_pll(enum pll_clocks pll, u32 infreq)
 {
 	u32 div, test_div, pll_num, pll_denom;
+	u64 temp64;
 
 	switch (pll) {
 	case PLL_SYS:
@@ -272,7 +273,10 @@ static u32 decode_pll(enum pll_clocks pll, u32 infreq)
 		}
 		test_div = 1 << (2 - test_div);
 
-		return infreq * (div + pll_num / pll_denom) / test_div;
+		temp64 = (u64)infreq;
+		temp64 *= pll_num;
+		do_div(temp64, pll_denom);
+		return infreq * div + (unsigned long)temp64;
 	default:
 		return 0;
 	}
-- 
2.32.0

[RESEND PATCH 2/3] imx6: clock: add support to get LCD pixel clock rate

[Dario Binacchi]

Add the get_lcd_clk() function to get the LCD pixel clock rate.

The patch has been tested on imx6ul platform.

Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
---

 arch/arm/include/asm/arch-mx6/clock.h |  2 +
 arch/arm/mach-imx/mx6/clock.c         | 58 +++++++++++++++++++++++++++
 2 files changed, 60 insertions(+)

diff --git a/arch/arm/include/asm/arch-mx6/clock.h b/arch/arm/include/asm/arch-mx6/clock.h
index 8ae49715789c..81af89c631f5 100644
--- a/arch/arm/include/asm/arch-mx6/clock.h
+++ b/arch/arm/include/asm/arch-mx6/clock.h
@@ -41,6 +41,8 @@ enum mxc_clock {
 	MXC_SATA_CLK,
 	MXC_NFC_CLK,
 	MXC_I2C_CLK,
+	MXC_LCDIF1_CLK,
+	MXC_LCDIF2_CLK,
 };
 
 enum ldb_di_clock {
diff --git a/arch/arm/mach-imx/mx6/clock.c b/arch/arm/mach-imx/mx6/clock.c
index 17d8dcd5c841..267d86ab4194 100644
--- a/arch/arm/mach-imx/mx6/clock.c
+++ b/arch/arm/mach-imx/mx6/clock.c
@@ -418,6 +418,60 @@ static u32 get_uart_clk(void)
 	return freq / (uart_podf + 1);
 }
 
+static u32 get_lcd_clk(unsigned int ifnum)
+{
+	u32 pll_rate;
+	u32 pred, postd;
+
+	if (!is_mx6sx() && !is_mx6ul() && !is_mx6ull() && !is_mx6sl() &&
+	    !is_mx6sll()) {
+		debug("This chip does't support lcd\n");
+		return 0;
+	}
+
+	pll_rate = decode_pll(PLL_VIDEO, MXC_HCLK);
+	if (ifnum == 1) {
+		if (!is_mx6sl()) {
+			pred = __raw_readl(&imx_ccm->cscdr2);
+			pred &= MXC_CCM_CSCDR2_LCDIF1_PRE_DIV_MASK;
+			pred = pred >> MXC_CCM_CSCDR2_LCDIF1_PRE_DIV_OFFSET;
+
+			postd = readl(&imx_ccm->cbcmr);
+			postd &= MXC_CCM_CBCMR_LCDIF1_PODF_MASK;
+			postd = postd >> MXC_CCM_CBCMR_LCDIF1_PODF_OFFSET;
+		} else {
+			pred = __raw_readl(&imx_ccm->cscdr2);
+			pred &= MXC_CCM_CSCDR2_LCDIF_PIX_PRE_DIV_MASK;
+			pred = pred >> MXC_CCM_CSCDR2_LCDIF_PIX_PRE_DIV_OFFSET;
+
+			postd = readl(&imx_ccm->cscmr1);
+			postd &= MXC_CCM_CSCMR1_LCDIF_PIX_PODF_OFFSET;
+			postd = postd >> MXC_CCM_CBCMR_LCDIF1_PODF_OFFSET;
+		}
+	} else if (ifnum == 2) {
+		if (is_mx6sx()) {
+			pred = __raw_readl(&imx_ccm->cscdr2);
+			pred &= MXC_CCM_CSCDR2_LCDIF2_PRE_DIV_MASK;
+			pred = pred >> MXC_CCM_CSCDR2_LCDIF2_PRE_DIV_OFFSET;
+
+			postd = readl(&imx_ccm->cscmr1);
+			postd &= MXC_CCM_CSCMR1_LCDIF2_PODF_MASK;
+			postd = postd >> MXC_CCM_CSCMR1_LCDIF2_PODF_OFFSET;
+
+		} else {
+			goto if_err;
+		}
+	} else {
+		goto if_err;
+	}
+
+	return DIV_ROUND_UP_ULL((u64)pll_rate, (postd + 1) * (pred + 1));
+
+if_err:
+	debug("This chip not support lcd iterface %d\n", ifnum);
+	return 0;
+}
+
 static u32 get_cspi_clk(void)
 {
 	u32 reg, cspi_podf;
@@ -1273,6 +1327,10 @@ unsigned int mxc_get_clock(enum mxc_clock clk)
 		return get_usdhc_clk(3);
 	case MXC_SATA_CLK:
 		return get_ahb_clk();
+	case MXC_LCDIF1_CLK:
+		return get_lcd_clk(1);
+	case MXC_LCDIF2_CLK:
+		return get_lcd_clk(2);
 	default:
 		printf("Unsupported MXC CLK: %d\n", clk);
 		break;
-- 
2.32.0

[RESEND PATCH 3/3] imx6: clock: print real pixel clock rate

[Dario Binacchi]

Add debug messages to print the real pixel clock rate, which may not be
the requested one.

Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>

---

 arch/arm/mach-imx/mx6/clock.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm/mach-imx/mx6/clock.c b/arch/arm/mach-imx/mx6/clock.c
index 267d86ab4194..1bdc568f9b14 100644
--- a/arch/arm/mach-imx/mx6/clock.c
+++ b/arch/arm/mach-imx/mx6/clock.c
@@ -802,6 +802,7 @@ void mxs_set_lcdclk(u32 base_addr, u32 freq)
 		}
 
 		enable_lcdif_clock(base_addr, 1);
+		debug("pixel clock = %u\n", mxc_get_clock(MXC_LCDIF1_CLK));
 	} else if (is_mx6sx()) {
 		/* Setting LCDIF2 for i.MX6SX */
 		if (enable_pll_video(pll_div, pll_num, pll_denom, post_div))
@@ -823,6 +824,7 @@ void mxs_set_lcdclk(u32 base_addr, u32 freq)
 				 MXC_CCM_CSCMR1_LCDIF2_PODF_OFFSET));
 
 		enable_lcdif_clock(base_addr, 1);
+		debug("pixel clock = %u\n", mxc_get_clock(MXC_LCDIF2_CLK));
 	}
 }
 
-- 
2.32.0

Re: [RESEND PATCH 0/3] imx6: clock: add support to get LCD pixel clock rate

[Fabio Estevam]

Hi Dario,

On Sat, Apr 22, 2023 at 11:11 AM Dario Binacchi
<dario.binacchi@amarulasolutions.com> wrote:
>
> The series adds a function to get the LCD pixel clock rate. Also
> improves video PLLL rate calculation.
>
>
> Dario Binacchi (3):
>   imx6: clock: improve calculations to get the PLL video rate
>   imx6: clock: add support to get LCD pixel clock rate
>   imx6: clock: print real pixel clock rate

For the series:

Reviewed-by: Fabio Estevam <festevam@denx.de>

[RESEND PATCH 2/3] imx6: clock: add support to get LCD pixel clock rate

[sbabic]

> Add the get_lcd_clk() function to get the LCD pixel clock rate.
> The patch has been tested on imx6ul platform.
> Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Applied to u-boot-imx, master, thanks !

Best regards,
Stefano Babic

-- 
=====================================================================
DENX Software Engineering GmbH,        Managing Director: Erika Unter  
HRB 165235 Munich,   Office: Kirchenstr.5, 82194 Groebenzell, Germany
Phone: +49-8142-66989-53 Fax: +49-8142-66989-80 Email: sbabic@denx.de
=====================================================================

[RESEND PATCH 3/3] imx6: clock: print real pixel clock rate

[sbabic]

> Add debug messages to print the real pixel clock rate, which may not be
> the requested one.
> Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Applied to u-boot-imx, master, thanks !

Best regards,
Stefano Babic

-- 
=====================================================================
DENX Software Engineering GmbH,        Managing Director: Erika Unter  
HRB 165235 Munich,   Office: Kirchenstr.5, 82194 Groebenzell, Germany
Phone: +49-8142-66989-53 Fax: +49-8142-66989-80 Email: sbabic@denx.de
=====================================================================

[RESEND PATCH 1/3] imx6: clock: improve calculations to get the PLL video rate

[sbabic]

> During some tests to check the pixel clock rate in the transition from
> U-Boot to the Linux kernel, I noticed that with the same configuration
> of the registers the debug messages reported different rates.
> The same Linux kernel calculations are now used to get the PLL video
> rate.
> Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
> Reviewed-by: Michael Trimarchi <michael@amarulasolutions.com>
Applied to u-boot-imx, master, thanks !

Best regards,
Stefano Babic

-- 
=====================================================================
DENX Software Engineering GmbH,        Managing Director: Erika Unter  
HRB 165235 Munich,   Office: Kirchenstr.5, 82194 Groebenzell, Germany
Phone: +49-8142-66989-53 Fax: +49-8142-66989-80 Email: sbabic@denx.de
=====================================================================