raiden_debug_spi.c: Add a delay following AP/EC flash enable

Add a delay following the AP and EC flash enable requests. This allows any power rails enabled by these signals to settle and to meet the power on to first SPI write timing requirements. Forward ports the downstream commit: https://chromium-review.googlesource.com/c/chromiumos/third_party/flashrom/+/2036738 Change-Id: I4c1777777ee67580605c6e6f4c0c228cccc392c7 Signed-off-by: Edward O'Callaghan <[email protected]> Reviewed-on: https://review.coreboot.org/c/flashrom/+/39312 Tested-by: build bot (Jenkins) <[email protected]> Reviewed-by: Stefan Reinauer <[email protected]>
midokura · Mar 11, 2020 · 3e67cb7 · 3e67cb7
1 parent 8b191f5
commit 3e67cb7
Showing 1 changed file with 9 additions and 0 deletions.
diff --git a/raiden_debug_spi.c b/raiden_debug_spi.c
@@ -562,6 +562,15 @@ int raiden_debug_spi_init(void)
 		return ret;
 	}
 
+	/*
+	 * Allow for power to settle on the AP and EC flash devices.
+	 * Load switches can have a 1-3 ms turn on time, and SPI flash devices
+	 * can require up to 10 ms from power on to the first write.
+	 */
+	if ((request_enable == RAIDEN_DEBUG_SPI_REQ_ENABLE_AP) ||
+		(request_enable == RAIDEN_DEBUG_SPI_REQ_ENABLE_EC))
+		usleep(50 * 1000);
+
 	register_spi_master(&spi_master_raiden_debug);
 	register_shutdown(shutdown, NULL);