summary refs log tree commit diff
path: root/arch
diff options
context:
space:
mode:
authorEugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>2017-09-12 21:20:45 +0300
committerVineet Gupta <vgupta@synopsys.com>2017-10-03 20:36:49 -0700
commit976e78a5226598cb582fe9ef98a72861adbc0e9c (patch)
treed2fd13138fada059726e766d29a81594fc7ddf5e /arch
parent6afa3bcf1f919c374d4606a7ed8078d3f67dfa90 (diff)
downloadlinux-976e78a5226598cb582fe9ef98a72861adbc0e9c.tar.gz
ARC: [plat-axs10x] sdio: Temporary fix of sdio ciu frequency
DW sdio controller has external ciu clock divider controlled
via register in SDIO IP. It divides sdio_ref_clk
(which comes from CGU) by 16 for default. So default mmcclk
clock (which comes to sdk_in) is 25000000 Hz.

So fix wrong current value (50000000 Hz) to actual 25000000 Hz.

Note this is a preventive fix, in line with similar change for HSDK
where this was actually needed. see:
http://lists.infradead.org/pipermail/linux-snps-arc/2017-September/002924.html

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/arc/boot/dts/axs10x_mb.dtsi9
1 files changed, 8 insertions, 1 deletions
diff --git a/arch/arc/boot/dts/axs10x_mb.dtsi b/arch/arc/boot/dts/axs10x_mb.dtsi
index 2367a67c5f10..e114000a84f5 100644
--- a/arch/arc/boot/dts/axs10x_mb.dtsi
+++ b/arch/arc/boot/dts/axs10x_mb.dtsi
@@ -44,7 +44,14 @@
 
 			mmcclk: mmcclk {
 				compatible = "fixed-clock";
-				clock-frequency = <50000000>;
+				/*
+				 * DW sdio controller has external ciu clock divider
+				 * controlled via register in SDIO IP. It divides
+				 * sdio_ref_clk (which comes from CGU) by 16 for
+				 * default. So default mmcclk clock (which comes
+				 * to sdk_in) is 25000000 Hz.
+				 */
+				clock-frequency = <25000000>;
 				#clock-cells = <0>;
 			};