cros_ec: Add vstore support

The EC can store small amounts of data for the benefit of the
verified boot process. Since the EC is seldom reset, this can allow the
AP to store data that survives a reboot or a suspend/resume cycle.

Add support for this.

Signed-off-by: Simon Glass <sjg@chromium.org>

1 files changed, 50 insertions, 2 deletions

diff --git a/drivers/misc/cros_ec_sandbox.c b/drivers/misc/cros_ec_sandbox.c
index 845876cfb0..cb8adc4495 100644
--- a/drivers/misc/cros_ec_sandbox.c
+++ b/drivers/misc/cros_ec_sandbox.c
@@ -62,6 +62,15 @@ struct ec_keymatrix_entry {
 	int keycode;	/* corresponding linux key code */
 };
 
+enum {
+	VSTORE_SLOT_COUNT	= 4,
+};
+
+struct vstore_slot {
+	bool locked;
+	u8 data[EC_VSTORE_SLOT_SIZE];
+};
+
 /**
  * struct ec_state - Information about the EC state
  *
@@ -75,7 +84,7 @@ struct ec_keymatrix_entry {
  * @keyscan: Current keyscan information (bit set for each row/column pressed)
  * @recovery_req: Keyboard recovery requested
  * @test_flags: Flags that control behaviour for tests
- * @switches: Current switches value (EC_SWITCH_)
+ * @slot_locked: Locked vstore slots (mask)
  */
 struct ec_state {
 	u8 vbnv_context[EC_VBNV_BLOCK_SIZE_V2];
@@ -88,6 +97,7 @@ struct ec_state {
 	uint8_t keyscan[KEYBOARD_COLS];
 	bool recovery_req;
 	uint test_flags;
+	struct vstore_slot slot[VSTORE_SLOT_COUNT];
 } s_state, *g_state;
 
 /**
@@ -495,13 +505,51 @@ static int process_cmd(struct ec_state *ec,
 		struct ec_response_get_features *resp = resp_data;
 
 		resp->flags[0] = EC_FEATURE_MASK_0(EC_FEATURE_FLASH) |
-			EC_FEATURE_MASK_0(EC_FEATURE_I2C);
+			EC_FEATURE_MASK_0(EC_FEATURE_I2C) |
+			EC_FEATURE_MASK_0(EC_FEATURE_VSTORE);
 		resp->flags[1] =
 			EC_FEATURE_MASK_1(EC_FEATURE_UNIFIED_WAKE_MASKS) |
 			EC_FEATURE_MASK_1(EC_FEATURE_ISH);
 		len = sizeof(*resp);
 		break;
 	}
+	case EC_CMD_VSTORE_INFO: {
+		struct ec_response_vstore_info *resp = resp_data;
+		int i;
+
+		resp->slot_count = VSTORE_SLOT_COUNT;
+		resp->slot_locked = 0;
+		for (i = 0; i < VSTORE_SLOT_COUNT; i++) {
+			if (ec->slot[i].locked)
+				resp->slot_locked |= 1 << i;
+		}
+		len = sizeof(*resp);
+		break;
+	};
+	case EC_CMD_VSTORE_WRITE: {
+		const struct ec_params_vstore_write *req = req_data;
+		struct vstore_slot *slot;
+
+		if (req->slot >= EC_VSTORE_SLOT_MAX)
+			return -EINVAL;
+		slot = &ec->slot[req->slot];
+		slot->locked = true;
+		memcpy(slot->data, req->data, EC_VSTORE_SLOT_SIZE);
+		len = 0;
+		break;
+	}
+	case EC_CMD_VSTORE_READ: {
+		const struct ec_params_vstore_read *req = req_data;
+		struct ec_response_vstore_read *resp = resp_data;
+		struct vstore_slot *slot;
+
+		if (req->slot >= EC_VSTORE_SLOT_MAX)
+			return -EINVAL;
+		slot = &ec->slot[req->slot];
+		memcpy(resp->data, slot->data, EC_VSTORE_SLOT_SIZE);
+		len = sizeof(*resp);
+		break;
+	}
 	default:
 		printf("   ** Unknown EC command %#02x\n", req_hdr->command);
 		return -1;