linux-surface/patches/5.4/0004-surface-sam-over-hid.patch

From 14bc7782c703218156fe5fd6b8df97a5f25f8d3e Mon Sep 17 00:00:00 2001
From: Maximilian Luz <luzmaximilian@gmail.com>
Date: Sat, 25 Jul 2020 17:19:53 +0200
Subject: [PATCH 4/6] surface-sam-over-hid

---
 drivers/i2c/i2c-core-acpi.c | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/drivers/i2c/i2c-core-acpi.c b/drivers/i2c/i2c-core-acpi.c
index ce70b5288472c..5df647c4d9a51 100644
--- a/drivers/i2c/i2c-core-acpi.c
+++ b/drivers/i2c/i2c-core-acpi.c
@@ -582,6 +582,28 @@ static int acpi_gsb_i2c_write_bytes(struct i2c_client *client,
 	return (ret == 1) ? 0 : -EIO;
 }
 
+static int acpi_gsb_i2c_write_raw_bytes(struct i2c_client *client,
+		u8 *data, u8 data_len)
+{
+	struct i2c_msg msgs[1];
+	int ret = AE_OK;
+
+	msgs[0].addr = client->addr;
+	msgs[0].flags = client->flags;
+	msgs[0].len = data_len + 1;
+	msgs[0].buf = data;
+
+	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
+
+	if (ret < 0) {
+		dev_err(&client->adapter->dev, "i2c write failed: %d\n", ret);
+		return ret;
+	}
+
+	/* 1 transfer must have completed successfully */
+	return (ret == 1) ? 0 : -EIO;
+}
+
 static acpi_status
 i2c_acpi_space_handler(u32 function, acpi_physical_address command,
 			u32 bits, u64 *value64,
@@ -683,6 +705,19 @@ i2c_acpi_space_handler(u32 function, acpi_physical_address command,
 		}
 		break;
 
+	case ACPI_GSB_ACCESS_ATTRIB_RAW_BYTES:
+		if (action == ACPI_READ) {
+			dev_warn(&adapter->dev,
+				 "protocol 0x%02x not supported for client 0x%02x\n",
+				 accessor_type, client->addr);
+			ret = AE_BAD_PARAMETER;
+			goto err;
+		} else {
+			status = acpi_gsb_i2c_write_raw_bytes(client,
+					gsb->data, info->access_length);
+		}
+		break;
+
 	default:
 		dev_warn(&adapter->dev, "protocol 0x%02x not supported for client 0x%02x\n",
 			 accessor_type, client->addr);
-- 
2.28.0