Skip to contentSkip to conversation

ARM: dts: dra7xx: Update spi-max-frequency for qspi slave node

PATCH New Vignesh R 2 participants 4 messages Nov 5, 2016 – Nov 11, 2016

Subsystems (2)
Arm (32-bit) SPI
lore
Share & tools
lore

Vignesh R

author
#0 lore raw

PATCH v3 1/2 ARM: dts: dra7xx: Update spi-max-frequency for qspi slave node

Update the spi-max-frequency property of m25p80 flash slave to match that of TI QSPI controller node, so that QSPI operations happen at maximum supported frequency of 76.8MHz.

Signed-off-by Vignesh R <[email protected]>
Reviewed-by Jagan Teki <[email protected]>

---

v3: No changes.

 arch/arm/dts/dra7-evm.dts          | 2 +-
 arch/arm/dts/dra72-evm-common.dtsi | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)
arch/arm/dts/dra7-evm.dts +1 -1
index fe755c05841d..be36d456206d 100644
@@ -505,7 +505,7 @@
 	spi-max-frequency = <76800000>;
 	m25p80 at 0 {
 		compatible = "s25fl256s1","spi-flash";
-		spi-max-frequency = <64000000>;
+		spi-max-frequency = <76800000>;
 		reg = <0>;
 		spi-tx-bus-width = <1>;
 		spi-rx-bus-width = <4>;
arch/arm/dts/dra72-evm-common.dtsi +1 -1
index b0993e5bf7e0..1e1ca725577f 100644
@@ -441,7 +441,7 @@
 	spi-max-frequency = <76800000>;
 	m25p80 at 0 {
 		compatible = "s25fl256s1", "spi-flash";
-		spi-max-frequency = <64000000>;
+		spi-max-frequency = <76800000>;
 		reg = <0>;
 		spi-tx-bus-width = <1>;
 		spi-rx-bus-width = <4>;
Signature · 1 line
2.10.2
author
#1 lore raw

PATCH v3 2/2 spi: ti_qspi: Fix baudrate divider calculation

Fix the divider calculation logic to choose a value so that the resulting baudrate is either equal to or closest possible baudrate less than the requested value. While at that, cleanup ti_spi_set_speed().

Signed-off-by Vignesh R <[email protected]>

---

v3: Move SCLK disable and enable blocks together.
v2: cleanup ti_spi_set_speed() a bit.

 drivers/spi/ti_qspi.c | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)
drivers/spi/ti_qspi.c +7 -9
index 52520dff6325..da0488659049 100644
@@ -16,6 +16,7 @@
 #include <asm/omap_gpio.h>
 #include <asm/omap_common.h>
 #include <asm/ti-common/ti-edma3.h>
+#include <linux/kernel.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 

@@ -118,21 +119,18 @@ static void ti_spi_set_speed(struct ti_qspi_priv *priv, uint hz)
 	if (!hz)
 		clk_div = 0;
 	else
-		clk_div = (priv->fclk / hz) - 1;
+		clk_div = DIV_ROUND_UP(priv->fclk, hz) - 1;
+
+	/* truncate clk_div value to QSPI_CLK_DIV_MAX */
+	if (clk_div > QSPI_CLK_DIV_MAX)
+		clk_div = QSPI_CLK_DIV_MAX;
 
 	debug("ti_spi_set_speed: hz: %d, clock divider %d\n", hz, clk_div);
 
 	/* disable SCLK */
 	writel(readl(&priv->base->clk_ctrl) & ~QSPI_CLK_EN,
 	       &priv->base->clk_ctrl);
-
-	/* assign clk_div values */
-	if (clk_div < 0)
-		clk_div = 0;
-	else if (clk_div > QSPI_CLK_DIV_MAX)
-		clk_div = QSPI_CLK_DIV_MAX;
-
-	/* enable SCLK */
+	/* enable SCLK and program the clk divider */
 	writel(QSPI_CLK_EN | clk_div, &priv->base->clk_ctrl);
 }
Signature · 1 line
2.10.2
#2 lore raw

PATCH v3 2/2 spi: ti_qspi: Fix baudrate divider calculation

Quoted 5 lines · Vignesh R

Fix the divider calculation logic to choose a value so that the resulting baudrate is either equal to or closest possible baudrate less than the requested value. While at that, cleanup ti_spi_set_speed().

Signed-off-by Vignesh R <[email protected]>

Applied to u-boot-spi/master

thanks!

Signature · 4 lines
Jagan Teki
Free Software Engineer | www.openedev.com
U-Boot, Linux | Upstream Maintainer
Hyderabad, India.
#3 lore raw

PATCH v3 1/2 ARM: dts: dra7xx: Update spi-max-frequency for qspi slave node

In reply to Vignesh R
Quoted 6 lines · Vignesh R

Update the spi-max-frequency property of m25p80 flash slave to match that of TI QSPI controller node, so that QSPI operations happen at maximum supported frequency of 76.8MHz.

Signed-off-by Vignesh R <[email protected]>
Reviewed-by Jagan Teki <[email protected]>

Applied to u-boot-spi/master

thanks!

Signature · 4 lines
Jagan Teki
Free Software Engineer | www.openedev.com
U-Boot, Linux | Upstream Maintainer
Hyderabad, India.