clearfog: Do not mess with the SPI direct mode
I re-read the datasheet, and it seems that the direct mode is really
meant to transactions which somehow target SPI flash. The protocol talks
about addresses and headers and dummy bytes which exactly correspond to
SPI NOR flash IO protocol. It is possible to turn these off and transfer
raw data, though.
When combined with a CS GPIO, this thing breaks horribly. I've seen my
logic analyzer saying that the CS pin went up in the middle of a second
byte, etc. That wasn't fun.
Going further, the Linux kernel commit b3c195b3a75b which added the
direct-mode feature explicitly talks about writes being tested, and
reads being supported, but untested. That's weird because I just cannot
see how that piece of code implements any reads. It seems that support
for reads actually got removed in a v4 posting of this patch, but the
commit message was never updated. Yay.
This reverts commit 8fd3c5d035fba6e4294f6ae57b974477bf97ef94.
Change-Id: Ic3e0939fcafcc94f15eb142ad53a89b66dff2714
Link: https://patchwork.kernel.org/patch/9124561/
diff --git a/board/czechlight/clearfog/czechlight-clearfog.dts b/board/czechlight/clearfog/czechlight-clearfog.dts
index 30bc5b1..53e212d 100644
--- a/board/czechlight/clearfog/czechlight-clearfog.dts
+++ b/board/czechlight/clearfog/czechlight-clearfog.dts
@@ -18,21 +18,6 @@
};
soc {
- ranges = <MBUS_ID(0xf0, 0x01) 0 0xf1000000 0x100000
- MBUS_ID(0x01, 0x1d) 0 0xfff00000 0x100000
- MBUS_ID(0x09, 0x19) 0 0xf1100000 0x10000
- MBUS_ID(0x09, 0x15) 0 0xf1110000 0x10000
- MBUS_ID(0x0c, 0x04) 0 0xf1200000 0x100000
- /* all above is from the upstream DTS */
-
- /* maybe-default mappings for SPI1 CS0 from the datasheet */
- MBUS_ID(0x01, 0x1a) 0 0xd4000000 0x4000000
- /* SPI1 CS1 */
- MBUS_ID(0x01, 0x5a) 0 0xd8000000 0x4000000
- /* SPI1 CS2 */
- MBUS_ID(0x01, 0x9a) 0 0xd0000000 0x4000000
- >;
-
internal-regs {
sdhci@d8000 {
/delete-property/ cd-gpios;
@@ -79,15 +64,6 @@
};
&spi1 {
- reg = <MBUS_ID(0xf0, 0x01) 0x10680 0x50> /* control */
- , <MBUS_ID(0x01, 0x1a) 0 0xffffffff> /* CS0 */
- , <0>
- /* <MBUS_ID(0x01, 0x5a) 0 0xffffffff>
- We're using CS GPIO which doesn't play well with the direct mode at all */
- , <MBUS_ID(0x01, 0x9a) 0 0xffffffff> /* CS2 */
- , <MBUS_ID(0x01, 0xda) 0 0xffffffff> /* CS3 */
- ;
-
cs-gpios = <0>, <&gpio0 22 GPIO_ACTIVE_HIGH>, <0>;
max14830: max14830@2 {