hammer: Support different IC types in touchpad FW update

Some Elan touchpad ICs have a different firmware sizes (48, 56, or 64
KB). We use CONFIG_TOUCHPAD_VIRTUAL_SIZE, set in the board file, to
determine the appropriate size, and, at runtime, we sanity check the
firmware size according to the IC type reported by the touchpad.

BRANCH=none
BUG=b:65188846
TEST=Manually modify the CONFIG_TOUCHPAD_VIRTUAL_SIZE in hammer,
     executed and verified both (1) "EC_ERROR_UNKNOWN" returned
     (2) ic_type shows 0x09 on EC console
TEST=Successfully flashing 48k firmware using CL:658920 on hammer and
     56k firmware on staff. With success here, we specifically test
     with different firmware version and make sure it reflected in
     hammerd's touchpad info.

Change-Id: Ib30917d8376d4a2e8b6137daabad2341ac48d1f8
Signed-off-by: Chun-Ta Lin <itspeter@google.com>
Reviewed-on: https://chromium-review.googlesource.com/664937
Commit-Ready: Chun-ta Lin <itspeter@chromium.org>
Tested-by: Chun-ta Lin <itspeter@chromium.org>
Reviewed-by: Nicolas Boichat <drinkcat@chromium.org>

2 files changed, 38 insertions, 15 deletions

diff --git a/board/hammer/board.h b/board/hammer/board.h
index a0028d22b0..5954b7b16d 100644
--- a/board/hammer/board.h
+++ b/board/hammer/board.h
@@ -141,19 +141,25 @@
 #define CONFIG_USB_HID_KEYBOARD_BACKLIGHT
 #define CONFIG_USB_HID_TOUCHPAD
 
+/* Virtual address for touchpad FW in USB updater. */
+#define CONFIG_TOUCHPAD_VIRTUAL_OFF	0x80000000
+
+/* Touchpad firmware size and dimension difference */
 #ifdef BOARD_STAFF
 /* TODO(b:38277869): Adjust values to match hardware. */
 #define CONFIG_USB_HID_TOUCHPAD_LOGICAL_MAX_X 3214
 #define CONFIG_USB_HID_TOUCHPAD_LOGICAL_MAX_Y 1840
 #define CONFIG_USB_HID_TOUCHPAD_PHYSICAL_MAX_X 1020 /* tenth of mm */
 #define CONFIG_USB_HID_TOUCHPAD_PHYSICAL_MAX_Y 584 /* tenth of mm */
+#define CONFIG_TOUCHPAD_VIRTUAL_SIZE (56*1024)
 #elif defined(BOARD_HAMMER)
 #define CONFIG_USB_HID_TOUCHPAD_LOGICAL_MAX_X 3207
 #define CONFIG_USB_HID_TOUCHPAD_LOGICAL_MAX_Y 1783
 #define CONFIG_USB_HID_TOUCHPAD_PHYSICAL_MAX_X 1018 /* tenth of mm */
 #define CONFIG_USB_HID_TOUCHPAD_PHYSICAL_MAX_Y 566 /* tenth of mm */
+#define CONFIG_TOUCHPAD_VIRTUAL_SIZE (48*1024)
 #else
-#error "No trackpad information for board."
+#error "No touchpad information for board."
 #endif
 
 #define CONFIG_KEYBOARD_DEBUG
@@ -175,20 +181,12 @@
 /* Enable PWM */
 #define CONFIG_PWM
 
-/* Enable elan trackpad driver */
+/* Enable Elan touchpad driver */
 #define CONFIG_TOUCHPAD
 #define CONFIG_TOUCHPAD_ELAN
 #define CONFIG_TOUCHPAD_I2C_PORT 0
 #define CONFIG_TOUCHPAD_I2C_ADDR (0x15 << 1)
 
-/* Virtual address for touchpad FW in USB updater. */
-#define CONFIG_TOUCHPAD_VIRTUAL_OFF	0x80000000
-/* TODO(itspeter): The CONFIG_TOUCHPAD_VIRTUAL_SIZE depends on IC.
- *                 b/65188846 will address this separately. It will only works
- *                 for this size as for now.
- */
-#define CONFIG_TOUCHPAD_VIRTUAL_SIZE	(48*1024)
-
 #define CONFIG_CURVE25519
 
 #define CONFIG_USB_PAIRING
diff --git a/driver/touchpad_elan.c b/driver/touchpad_elan.c
index 070602bf5b..3eae8f5c12 100644
--- a/driver/touchpad_elan.c
+++ b/driver/touchpad_elan.c
@@ -30,9 +30,11 @@
 #define ETP_I2C_RESET			0x0100
 #define ETP_I2C_WAKE_UP			0x0800
 #define ETP_I2C_SLEEP			0x0801
+
 #define ETP_I2C_STAND_CMD		0x0005
 #define ETP_I2C_UNIQUEID_CMD		0x0101
 #define ETP_I2C_FW_VERSION_CMD		0x0102
+#define ETP_I2C_OSM_VERSION_CMD		0x0103
 #define ETP_I2C_XY_TRACENUM_CMD		0x0105
 #define ETP_I2C_MAX_X_AXIS_CMD		0x0106
 #define ETP_I2C_MAX_Y_AXIS_CMD		0x0107
@@ -74,10 +76,9 @@
 #define ETP_FW_IAP_INTF_ERR		(1 << 4)
 
 #ifdef CONFIG_USB_UPDATE
-/* TODO(b/65188846): The actual FW_PAGE_COUNT depends on IC. */
+/* The actual FW_SIZE depends on IC. */
+#define FW_SIZE			CONFIG_TOUCHPAD_VIRTUAL_SIZE
 #define FW_PAGE_SIZE		64
-#define FW_PAGE_COUNT		768
-#define FW_SIZE			(FW_PAGE_SIZE*FW_PAGE_COUNT)
 #endif
 
 struct {
@@ -363,12 +364,28 @@ static int elan_in_main_mode(void)
 	return val & ETP_I2C_MAIN_MODE_ON;
 }
 
+static int elan_get_ic_page_count(void)
+{
+	uint16_t ic_type;
+
+	elan_tp_read_cmd(ETP_I2C_OSM_VERSION_CMD, &ic_type);
+	CPRINTS("%s: ic_type:%04X.", __func__, ic_type);
+	switch (ic_type >> 8) {
+	case 0x09:
+		return 768;
+	case 0x0D:
+		return 896;
+	case 0x00:
+		return 1024;
+	}
+	return -1;
+}
+
 static int elan_prepare_for_update(void)
 {
 	uint16_t rx_buf;
 	int initial_mode;
 
-	/* TODO(itspeter): Let it work for different IC size. */
 	initial_mode = elan_in_main_mode();
 	if (!initial_mode) {
 		CPRINTS("%s: In IAP mode, reset IC.", __func__);
@@ -440,11 +457,19 @@ static int touchpad_update_page(const uint8_t *data)
 int touchpad_update_write(int offset, int size, const uint8_t *data)
 {
 	static int iap_addr = -1;
-	int addr, rv;
+	int addr, rv, page_count;
 
 	CPRINTS("%s %08x %d", __func__, offset, size);
 
 	if (offset == 0) {
+		/* Verify the IC type is aligned with defined firmware size */
+		page_count = elan_get_ic_page_count();
+		if (FW_PAGE_SIZE * page_count != FW_SIZE) {
+			CPRINTS("%s: IC(%d*%d) size and FW_SIZE(%d) mismatch",
+				__func__, page_count, FW_PAGE_SIZE, FW_SIZE);
+			return EC_ERROR_UNKNOWN;
+		}
+
 		gpio_disable_interrupt(GPIO_TOUCHPAD_INT);
 		CPRINTS("%s: prepare fw update.", __func__);
 		rv = elan_prepare_for_update();