chromeec: Access ID + flags through ACPI I/O ports

If CONFIG_EC_GOOGLE_CHROMEEC_ACPI_MEMMAP is set, access to memmap data
should go through the ACPI CMD / DATA ports.

BUG=chrome-os-partner:38224
TEST=Manual on Samus. Define EC_GOOGLE_CHROMEEC_ACPI_MEMMAP. Verify
system boots cleanly.
BRANCH=None

Change-Id: I9d19704df259f5a25e04a9b07b23968e93fe6302
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: d0b59b040a7889d2d1bd6eeaf57dd960bd29927d
Original-Signed-off-by: Shawn Nematbakhsh <shawnn@chromium.org>
Original-Change-Id: I405e28828457a1fd83a7ece7192a7e7d0a37be95
Original-Reviewed-on: https://chromium-review.googlesource.com/262932
Original-Reviewed-by: Randall Spangler <rspangler@chromium.org>
Original-Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-on: http://review.coreboot.org/9893
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

1 files changed, 61 insertions, 22 deletions

diff --git a/src/ec/google/chromeec/ec_lpc.c b/src/ec/google/chromeec/ec_lpc.c
index 061c1032c1..f5f5434548 100644
--- a/src/ec/google/chromeec/ec_lpc.c
+++ b/src/ec/google/chromeec/ec_lpc.c
@@ -29,13 +29,74 @@
 #include "ec.h"
 #include "ec_commands.h"
 
+static int google_chromeec_wait_ready(u16 port)
+{
+	u8 ec_status = inb(port);
+	u32 time_count = 0;
+
+	/*
+	 * One second is more than plenty for any EC operation to complete
+	 * (and the bus accessing/code execution) overhead will make the
+	 * timeout even longer.
+	 */
+#define MAX_EC_TIMEOUT_US 1000000
+
+	while (ec_status &
+	       (EC_LPC_CMDR_PENDING | EC_LPC_CMDR_BUSY)) {
+		udelay(1);
+		if (time_count++ == MAX_EC_TIMEOUT_US)
+			return -1;
+		ec_status = inb(port);
+	}
+	return 0;
+}
+
+#if CONFIG_EC_GOOGLE_CHROMEEC_ACPI_MEMMAP
+/* Read memmap data through ACPI port 66/62 */
+static int read_memmap(u8 *data, u8 offset)
+{
+	if (google_chromeec_wait_ready(EC_LPC_ADDR_ACPI_CMD)) {
+		printk(BIOS_ERR, "Timeout waiting for EC ready!\n");
+		return -1;
+	}
+
+	/* Issue the ACPI read command */
+	outb(EC_CMD_ACPI_READ, EC_LPC_ADDR_ACPI_CMD);
+
+	if (google_chromeec_wait_ready(EC_LPC_ADDR_ACPI_CMD)) {
+		printk(BIOS_ERR, "Timeout waiting for EC READ_EVENT!\n");
+		return -1;
+	}
+
+	/* Write data address */
+	outb(offset + EC_ACPI_MEM_MAPPED_BEGIN, EC_LPC_ADDR_ACPI_DATA);
+
+	if (google_chromeec_wait_ready(EC_LPC_ADDR_ACPI_CMD)) {
+		printk(BIOS_ERR, "Timeout waiting for EC DATA!\n");
+		return -1;
+	}
+
+	*data = inb(EC_LPC_ADDR_ACPI_DATA);
+	return 0;
+}
+#endif
+
 static int google_chromeec_command_version(void)
 {
 	u8 id1, id2, flags;
 
+#if CONFIG_EC_GOOGLE_CHROMEEC_ACPI_MEMMAP
+	if (read_memmap(&id1, EC_MEMMAP_ID) ||
+	    read_memmap(&id2, EC_MEMMAP_ID + 1) ||
+	    read_memmap(&flags, EC_MEMMAP_HOST_CMD_FLAGS)) {
+		printk(BIOS_ERR, "Error reading memmap data.\n");
+		return -1;
+	}
+#else
 	id1 = inb(EC_LPC_ADDR_MEMMAP + EC_MEMMAP_ID);
 	id2 = inb(EC_LPC_ADDR_MEMMAP + EC_MEMMAP_ID + 1);
 	flags = inb(EC_LPC_ADDR_MEMMAP + EC_MEMMAP_HOST_CMD_FLAGS);
+#endif
 
 	if (id1 != 'E' || id2 != 'C') {
 		printk(BIOS_ERR, "Missing Chromium EC memory map.\n");
@@ -53,28 +114,6 @@ static int google_chromeec_command_version(void)
 	}
 }
 
-static int google_chromeec_wait_ready(u16 port)
-{
-	u8 ec_status = inb(port);
-	u32 time_count = 0;
-
-	/*
-	 * One second is more than plenty for any EC operation to complete
-	 * (and the bus accessing/code execution) overhead will make the
-	 * timeout even longer.
-	 */
-#define MAX_EC_TIMEOUT_US 1000000
-
-	while (ec_status &
-	       (EC_LPC_CMDR_PENDING | EC_LPC_CMDR_BUSY)) {
-		udelay(1);
-		if (time_count++ == MAX_EC_TIMEOUT_US)
-			return -1;
-		ec_status = inb(port);
-	}
-	return 0;
-}
-
 static int google_chromeec_command_v3(struct chromeec_command *cec_command)
 {
 	struct ec_host_request rq;