drm/amdgpu: Enable reading FRU chip via I2C v3

Allow for reading of information like manufacturer, product number
and serial number from the FRU chip. Report the serial number as
the new sysfs file serial_number. Note that this only works on
server cards, as consumer cards do not feature the FRU chip, which
contains this information.

v2: Add documentation to amdgpu.rst, add helper functions,
    rename functions for consistency, fix bad starting offset
v3: Remove testing definitions

Signed-off-by: Kent Russell <kent.russell@amd.com>
Reviewed-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 143 insertions, 0 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fru_eeprom.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_fru_eeprom.c
new file mode 100644
index 000000000000..990dee6e22d5
--- /dev/null
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fru_eeprom.c
@@ -0,0 +1,143 @@
+/*
+ * Copyright 2019 Advanced Micro Devices, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ */
+#include "amdgpu.h"
+#include "amdgpu_i2c.h"
+#include "smu_v11_0_i2c.h"
+#include "atom.h"
+
+#define I2C_PRODUCT_INFO_ADDR		0xAC
+#define I2C_PRODUCT_INFO_ADDR_SIZE	0x2
+#define I2C_PRODUCT_INFO_OFFSET		0xC0
+
+int amdgpu_fru_read_eeprom(struct amdgpu_device *adev, uint32_t addrptr,
+			   unsigned char *buff)
+{
+	int ret, size;
+	struct i2c_msg msg = {
+			.addr   = I2C_PRODUCT_INFO_ADDR,
+			.flags  = I2C_M_RD,
+			.buf    = buff,
+	};
+	buff[0] = 0;
+	buff[1] = addrptr;
+	msg.len = I2C_PRODUCT_INFO_ADDR_SIZE + 1;
+	ret = i2c_transfer(&adev->pm.smu_i2c, &msg, 1);
+
+	if (ret < 1) {
+		DRM_WARN("FRU: Failed to get size field");
+		return ret;
+	}
+
+	/* The size returned by the i2c requires subtraction of 0xC0 since the
+	 * size apparently always reports as 0xC0+actual size.
+	 */
+	size = buff[2] - I2C_PRODUCT_INFO_OFFSET;
+	/* Add 1 since address field was 1 byte */
+	buff[1] = addrptr + 1;
+
+	msg.len = I2C_PRODUCT_INFO_ADDR_SIZE + size;
+	ret = i2c_transfer(&adev->pm.smu_i2c, &msg, 1);
+
+	if (ret < 1) {
+		DRM_WARN("FRU: Failed to get data field");
+		return ret;
+	}
+
+	return size;
+}
+
+int amdgpu_fru_get_product_info(struct amdgpu_device *adev)
+{
+	unsigned char buff[32];
+	int addrptr = 0, size = 0;
+
+	/* If algo exists, it means that the i2c_adapter's initialized */
+	if (!adev->pm.smu_i2c.algo) {
+		DRM_WARN("Cannot access FRU, EEPROM accessor not initialized");
+		return 0;
+	}
+
+	/* There's a lot of repetition here. This is due to the FRU having
+	 * variable-length fields. To get the information, we have to find the
+	 * size of each field, and then keep reading along and reading along
+	 * until we get all of the data that we want. We use addrptr to track
+	 * the address as we go
+	 */
+
+	/* The first fields are all of size 1-byte, from 0-7 are offsets that
+	 * contain information that isn't useful to us.
+	 * Bytes 8-a are all 1-byte and refer to the size of the entire struct,
+	 * and the language field, so just start from 0xb, manufacturer size
+	 */
+	addrptr = 0xb;
+	size = amdgpu_fru_read_eeprom(adev, addrptr, buff);
+	if (size < 1) {
+		DRM_ERROR("Failed to read FRU Manufacturer, ret:%d", size);
+		return size;
+	}
+
+	/* Increment the addrptr by the size of the field, and 1 due to the
+	 * size field being 1 byte. This pattern continues below.
+	 */
+	addrptr += size + 1;
+	size = amdgpu_fru_read_eeprom(adev, addrptr, buff);
+	if (size < 1) {
+		DRM_ERROR("Failed to read FRU product name, ret:%d", size);
+		return size;
+	}
+
+	/* Start at 2 due to buff using fields 0 and 1 for the address */
+	memcpy(adev->product_name, &buff[2], size);
+	adev->product_name[size] = '\0';
+
+	addrptr += size + 1;
+	size = amdgpu_fru_read_eeprom(adev, addrptr, buff);
+	if (size < 1) {
+		DRM_ERROR("Failed to read FRU product number, ret:%d", size);
+		return size;
+	}
+
+	memcpy(adev->product_number, &buff[2], size);
+	adev->product_number[size] = '\0';
+
+	addrptr += size + 1;
+	size = amdgpu_fru_read_eeprom(adev, addrptr, buff);
+
+	if (size < 1) {
+		DRM_ERROR("Failed to read FRU product version, ret:%d", size);
+		return size;
+	}
+
+	addrptr += size + 1;
+	size = amdgpu_fru_read_eeprom(adev, addrptr, buff);
+
+	if (size < 1) {
+		DRM_ERROR("Failed to read FRU serial number, ret:%d", size);
+		return size;
+	}
+
+	memcpy(adev->serial, &buff[2], size);
+	adev->serial[size] = '\0';
+
+	return 0;
+}