diff mbox

[U-Boot,v9,39/49] rockchip: spi: Remember the last speed to avoid re-setting it

Message ID 1453430653-3280-40-git-send-email-sjg@chromium.org
State Accepted
Delegated to: Simon Glass
Headers show

Commit Message

Simon Glass Jan. 22, 2016, 2:44 a.m. UTC 
Rather than changing the clock to the same value on every transaction,
remember the last value and don't adjust the clock unless it is necessary.

Signed-off-by: Simon Glass <sjg@chromium.org>
---

Changes in v9: None
Changes in v2: None

 drivers/spi/rk_spi.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

Comments

Simon Glass Jan. 22, 2016, 3:18 p.m. UTC | #1 
On 21 January 2016 at 19:44, Simon Glass <sjg@chromium.org> wrote:
> Rather than changing the clock to the same value on every transaction,
> remember the last value and don't adjust the clock unless it is necessary.
>
> Signed-off-by: Simon Glass <sjg@chromium.org>
> ---
>
> Changes in v9: None
> Changes in v2: None
>
>  drivers/spi/rk_spi.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)

Applied to u-boot-rockchip.
diff mbox

Patch

diff --git a/drivers/spi/rk_spi.c b/drivers/spi/rk_spi.c
index 2b58393..aaf139d 100644
--- a/drivers/spi/rk_spi.c
+++ b/drivers/spi/rk_spi.c
@@ -44,6 +44,7 @@  struct rockchip_spi_priv {
 	u8 bits_per_word;		/* max 16 bits per word */
 	u8 n_bytes;
 	unsigned int speed_hz;
+	unsigned int last_speed_hz;
 	unsigned int tmode;
 	uint input_rate;
 };
@@ -82,6 +83,7 @@  static void rkspi_set_clk(struct rockchip_spi_priv *priv, uint speed)
 	debug("spi speed %u, div %u\n", speed, clk_div);
 
 	writel(clk_div, &priv->regs->baudr);
+	priv->last_speed_hz = speed;
 }
 
 static int rkspi_wait_till_not_busy(struct rockchip_spi *regs)
@@ -212,7 +214,8 @@  static int rockchip_spi_claim_bus(struct udevice *dev)
 		return -EPROTONOSUPPORT;
 	}
 
-	rkspi_set_clk(priv, priv->speed_hz);
+	if (priv->speed_hz != priv->last_speed_hz)
+		rkspi_set_clk(priv, priv->speed_hz);
 
 	/* Operation Mode */
 	ctrlr0 = OMOD_MASTER << OMOD_SHIFT;