usb_update: Add a way to fetch touchpad information

We'd like to know touchpad vendor/product id, as well as currently
running FW version. This CL does that by adding a new
UPDATE_EXTRA_CMD_TOUCHPAD_INFO command.

We also make the interface more generic by adding a CONFIG_TOUCHPAD
configuration option, even though we only support Elan touchpads
currently.

BRANCH=none
BUG=b:63418037
TEST=Flash hammer, ./usb_updater -t

Change-Id: Icce3c785eb3235bcc50b2ae7c0227ce11cbc9f2b
Signed-off-by: Nicolas Boichat <drinkcat@google.com>
Reviewed-on: https://chromium-review.googlesource.com/593000
Commit-Ready: Nicolas Boichat <drinkcat@chromium.org>
Tested-by: Nicolas Boichat <drinkcat@chromium.org>
Reviewed-by: Chun-ta Lin <itspeter@chromium.org>

board/hammer/board.h

@@ -175,6 +175,7 @@
 #define CONFIG_PWM
 
 /* Enable elan trackpad driver */
+#define CONFIG_TOUCHPAD
 #define CONFIG_TOUCHPAD_ELAN
 #define CONFIG_TOUCHPAD_I2C_PORT 0
 #define CONFIG_TOUCHPAD_I2C_ADDR (0x15 << 1)

common/usb_update.c

@@ -298,6 +298,26 @@ static int try_vendor_command(struct consumer const *consumer, size_t count)
 #endif
 #endif /* CONFIG_ROLLBACK_SECRET_SIZE */
 #endif /* CONFIG_ROLLBACK */
+#ifdef CONFIG_TOUCHPAD
+		case UPDATE_EXTRA_CMD_TOUCHPAD_INFO: {
+			struct touchpad_info tp = { 0 };
+
+			if (data_count != 0) {
+				response = EC_RES_INVALID_PARAM;
+				break;
+			}
+
+			response_size = touchpad_get_info(&tp);
+			if (response_size < 1) {
+				response = EC_RES_ERROR;
+				break;
+			}
+
+			QUEUE_ADD_UNITS(&update_to_usb,
+					&tp, response_size);
+			return 1;
+		}
+#endif
 		default:
 			response = EC_RES_INVALID_COMMAND;
 		}

driver/touchpad_elan.c

@@ -10,6 +10,7 @@
 #include "i2c.h"
 #include "task.h"
 #include "timer.h"
+#include "update_fw.h"
 #include "util.h"
 #include "usb_hid_touchpad.h"
 
@@ -22,16 +23,21 @@
 /* How to talk to the controller */
 /******************************************************************************/
 
+#define ELAN_VENDOR_ID			0x04f3
+
 #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_XY_TRACENUM_CMD		0x0105
 #define ETP_I2C_MAX_X_AXIS_CMD		0x0106
 #define ETP_I2C_MAX_Y_AXIS_CMD		0x0107
 #define ETP_I2C_RESOLUTION_CMD		0x0108
 #define ETP_I2C_PRESSURE_CMD		0x010A
 #define ETP_I2C_SET_CMD			0x0300
+#define ETP_I2C_FW_CHECKSUM_CMD		0x030F
 
 #define ETP_ENABLE_ABS		0x0001
 
@@ -277,6 +283,35 @@ out:
 	return rv;
 }
 
+#ifdef CONFIG_USB_UPDATE
+int touchpad_get_info(struct touchpad_info *tp)
+{
+	int rv;
+	uint16_t val;
+
+	tp->status = EC_RES_SUCCESS;
+	tp->vendor = ELAN_VENDOR_ID;
+
+	/* Get unique ID, FW, SM version. */
+	rv = elan_tp_read_cmd(ETP_I2C_UNIQUEID_CMD, &val);
+	if (rv)
+		return -1;
+	tp->elan.id = val;
+
+	rv = elan_tp_read_cmd(ETP_I2C_FW_VERSION_CMD, &val);
+	if (rv)
+		return -1;
+	tp->elan.fw_version = val & 0xff;
+
+	rv = elan_tp_read_cmd(ETP_I2C_FW_CHECKSUM_CMD, &val);
+	if (rv)
+		return -1;
+	tp->elan.fw_checksum = val;
+
+	return sizeof(*tp);
+}
+#endif
+
 void elan_tp_interrupt(enum gpio_signal signal)
 {
 	task_wake(TASK_ID_TOUCHPAD);

include/config.h

@@ -2251,6 +2251,9 @@
 /*****************************************************************************/
 /* Touchpad config */
 
+/* Enable touchpad, you must pick a driver (currently, only Elan exists) */
+#undef CONFIG_TOUCHPAD
+
 /* Enable Elan driver */
 #undef CONFIG_TOUCHPAD_ELAN
 

include/update_fw.h

@@ -164,6 +164,7 @@ enum update_extra_command {
 	UPDATE_EXTRA_CMD_UNLOCK_ROLLBACK = 4,
 	UPDATE_EXTRA_CMD_INJECT_ENTROPY = 5,
 	UPDATE_EXTRA_CMD_PAIR_CHALLENGE = 6,
+	UPDATE_EXTRA_CMD_TOUCHPAD_INFO = 7,
 };
 
 /*
@@ -188,6 +189,19 @@ struct pair_challenge_response {
 	uint8_t authenticator[16];
 } __packed;
 
+struct touchpad_info {
+	uint8_t status; /* = EC_RES_SUCCESS */
+	uint8_t reserved; /* padding */
+	uint16_t vendor; /* Vendor USB id */
+
+	/* Vendor specific data. */
+	struct {
+		uint16_t id;
+		uint16_t fw_version;
+		uint16_t fw_checksum;
+	} elan;
+} __packed;
+
 void fw_update_command_handler(void *body,
 			       size_t cmd_size,
 			       size_t *response_size);
@@ -213,4 +227,7 @@ enum {
 	UPDATE_RWSIG_BUSY = 10,
 };
 
+/* Obtain touchpad information */
+int touchpad_get_info(struct touchpad_info *tp);
+
 #endif  /* ! __CROS_EC_UPDATE_FW_H */