On 2016/11/14 18:04, Jaehoon Chung wrote:
On 11/14/2016 07:00 PM, Jun Nie wrote:
2016-11-14 15:58 GMT+08:00 Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>:
On 2016/11/8 9:24, Jun Nie wrote:
Document the device-tree binding of ZTE MMC host on
ZX296718 SoC.
Signed-off-by: Jun Nie <jun.nie@xxxxxxxxxx>
---
.../devicetree/bindings/mmc/zx-dw-mshc.txt | 35
++++++++++++++++++++++
1 file changed, 35 insertions(+)
create mode 100644 Documentation/devicetree/bindings/mmc/zx-dw-mshc.txt
diff --git a/Documentation/devicetree/bindings/mmc/zx-dw-mshc.txt
b/Documentation/devicetree/bindings/mmc/zx-dw-mshc.txt
new file mode 100644
index 0000000..c175c4b
--- /dev/null
+++ b/Documentation/devicetree/bindings/mmc/zx-dw-mshc.txt
@@ -0,0 +1,35 @@
+* ZTE specific extensions to the Synopsys Designware Mobile Storage
+ Host Controller
+
+The Synopsys designware mobile storage host controller is used to
interface
+a SoC with storage medium such as eMMC or SD/MMC cards. This file
documents
+differences between the core Synopsys dw mshc controller properties
described
+by synopsys-dw-mshc.txt and the properties used by the ZTE specific
+extensions to the Synopsys Designware Mobile Storage Host Controller.
+
+Required Properties:
+
+* compatible: should be
+ - "zte,zx296718-dw-mshc": for ZX SoCs
+
+Example:
+
+ mmc1: mmc@1110000 {
+ compatible = "zte,zx296718-dw-mshc";
+ #address-cells = <1>;
+ #size-cells = <0>;
+ reg = <0x01110000 0x1000>;
+ interrupts = <GIC_SPI 15 IRQ_TYPE_LEVEL_HIGH>;
+ fifo-depth = <32>;
+ data-addr = <0x200>;
+ fifo-watermark-aligned;
+ bus-width = <4>;
+ clock-frequency = <50000000>;
do you need both clock-frequency and max-frequency here?
According to dts document, clock-frequency is for clock configuration
when dw core probe. max-frequency is for mmc core to limit max
frequency for any cards at any time. Do you have any suggestion? Thank
you for your time!
As i know, Jun's comment is right. :)
clock-frequency should be used with clk_set_rate().
yup, I was thinking that should we reuse max-frequency instead of
clock-frequency in the future? I saw most of the DT(I didn't check all
of them) assign clock-frequency to the same value as max of clock-
freq-min-max. I think it's pointless if the clock-frequency is different
from max-frequency as both of them will be setted via dw_mmc and finally
we only take min(clock-frequency, max-frquency). Was I missing
something?
What is your opinion, Jaehoon and Jun? :)
+ clocks = <&topcrm SD0_AHB>, <&topcrm SD0_WCLK>;
+ clock-names = "biu", "ciu";
+ num-slots = <1>;
+ max-frequency = <50000000>;
+ cap-sdio-irq;
+ cap-sd-highspeed;
+ status = "disabled";
+ };
--
Best Regards
Shawn Lin
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--
Best Regards
Shawn Lin
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