drm: Add SCDC helpers (3ad33ae2) · Commits · 戴 / test

Documentation/gpu/drm-kms-helpers.rst

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		@@ -223,6 +223,18 @@ EDID Helper Functions Reference
		.. kernel-doc:: drivers/gpu/drm/drm_edid.c
		:export:

		SCDC Helper Functions Reference
		===============================

		.. kernel-doc:: drivers/gpu/drm/drm_scdc_helper.c
		:doc: scdc helpers

		.. kernel-doc:: include/drm/drm_scdc_helper.h
		:internal:

		.. kernel-doc:: drivers/gpu/drm/drm_scdc_helper.c
		:export:

		Rectangle Utilities Reference
		=============================

drivers/gpu/drm/Makefile

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		@@ -31,7 +31,8 @@ drm-$(CONFIG_DEBUG_FS) += drm_debugfs.o drm_debugfs_crc.o
		drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o drm_probe_helper.o \
		drm_plane_helper.o drm_dp_mst_topology.o drm_atomic_helper.o \
		drm_kms_helper_common.o drm_dp_dual_mode_helper.o \
		drm_simple_kms_helper.o drm_modeset_helper.o
		drm_simple_kms_helper.o drm_modeset_helper.o \
		drm_scdc_helper.o

		drm_kms_helper-$(CONFIG_DRM_LOAD_EDID_FIRMWARE) += drm_edid_load.o
		drm_kms_helper-$(CONFIG_DRM_FBDEV_EMULATION) += drm_fb_helper.o

drivers/gpu/drm/drm_scdc_helper.c

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		/*
		* Copyright (c) 2015 NVIDIA Corporation. All rights reserved.
		*
		* 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, sub license,
		* 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 (including the
		* next paragraph) 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 NON-INFRINGEMENT. IN NO EVENT SHALL
		* THE AUTHORS OR COPYRIGHT HOLDERS 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 <linux/slab.h>

		#include <drm/drm_scdc_helper.h>

		/**
		* DOC: scdc helpers
		*
		* Status and Control Data Channel (SCDC) is a mechanism introduced by the
		* HDMI 2.0 specification. It is a point-to-point protocol that allows the
		* HDMI source and HDMI sink to exchange data. The same I2C interface that
		* is used to access EDID serves as the transport mechanism for SCDC.
		*/

		#define SCDC_I2C_SLAVE_ADDRESS 0x54

		/**
		* drm_scdc_read - read a block of data from SCDC
		* @adapter: I2C controller
		* @offset: start offset of block to read
		* @buffer: return location for the block to read
		* @size: size of the block to read
		*
		* Reads a block of data from SCDC, starting at a given offset.
		*
		* Returns:
		* 0 on success, negative error code on failure.
		*/
		ssize_t drm_scdc_read(struct i2c_adapter adapter, u8 offset, void buffer,
		size_t size)
		{
		int ret;
		struct i2c_msg msgs[2] = {
		{
		.addr = SCDC_I2C_SLAVE_ADDRESS,
		.flags = 0,
		.len = 1,
		.buf = &offset,
		}, {
		.addr = SCDC_I2C_SLAVE_ADDRESS,
		.flags = I2C_M_RD,
		.len = size,
		.buf = buffer,
		}
		};

		ret = i2c_transfer(adapter, msgs, ARRAY_SIZE(msgs));
		if (ret < 0)
		return ret;
		if (ret != ARRAY_SIZE(msgs))
		return -EPROTO;

		return 0;
		}
		EXPORT_SYMBOL(drm_scdc_read);

		/**
		* drm_scdc_write - write a block of data to SCDC
		* @adapter: I2C controller
		* @offset: start offset of block to write
		* @buffer: block of data to write
		* @size: size of the block to write
		*
		* Writes a block of data to SCDC, starting at a given offset.
		*
		* Returns:
		* 0 on success, negative error code on failure.
		*/
		ssize_t drm_scdc_write(struct i2c_adapter *adapter, u8 offset,
		const void *buffer, size_t size)
		{
		struct i2c_msg msg = {
		.addr = SCDC_I2C_SLAVE_ADDRESS,
		.flags = 0,
		.len = 1 + size,
		.buf = NULL,
		};
		void *data;
		int err;

		data = kmalloc(1 + size, GFP_TEMPORARY);
		if (!data)
		return -ENOMEM;

		msg.buf = data;

		memcpy(data, &offset, sizeof(offset));
		memcpy(data + 1, buffer, size);

		err = i2c_transfer(adapter, &msg, 1);

		kfree(data);

		if (err < 0)
		return err;
		if (err != 1)
		return -EPROTO;

		return 0;
		}
		EXPORT_SYMBOL(drm_scdc_write);

include/drm/drm_scdc_helper.h

0 → 100644

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		/*
		* Copyright (c) 2015 NVIDIA Corporation. All rights reserved.
		*
		* 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, sub license,
		* 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 (including the
		* next paragraph) 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 NON-INFRINGEMENT. IN NO EVENT SHALL
		* THE AUTHORS OR COPYRIGHT HOLDERS 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.
		*/

		#ifndef DRM_SCDC_HELPER_H
		#define DRM_SCDC_HELPER_H

		#include <linux/i2c.h>
		#include <linux/types.h>

		#define SCDC_SINK_VERSION 0x01

		#define SCDC_SOURCE_VERSION 0x02

		#define SCDC_UPDATE_0 0x10
		#define SCDC_READ_REQUEST_TEST (1 << 2)
		#define SCDC_CED_UPDATE (1 << 1)
		#define SCDC_STATUS_UPDATE (1 << 0)

		#define SCDC_UPDATE_1 0x11

		#define SCDC_TMDS_CONFIG 0x20
		#define SCDC_TMDS_BIT_CLOCK_RATIO_BY_40 (1 << 1)
		#define SCDC_TMDS_BIT_CLOCK_RATIO_BY_10 (0 << 1)
		#define SCDC_SCRAMBLING_ENABLE (1 << 0)

		#define SCDC_SCRAMBLER_STATUS 0x21
		#define SCDC_SCRAMBLING_STATUS (1 << 0)

		#define SCDC_CONFIG_0 0x30
		#define SCDC_READ_REQUEST_ENABLE (1 << 0)

		#define SCDC_STATUS_FLAGS_0 0x40
		#define SCDC_CH2_LOCK (1 < 3)
		#define SCDC_CH1_LOCK (1 < 2)
		#define SCDC_CH0_LOCK (1 < 1)
		#define SCDC_CH_LOCK_MASK (SCDC_CH2_LOCK \| SCDC_CH1_LOCK \| SCDC_CH0_LOCK)
		#define SCDC_CLOCK_DETECT (1 << 0)

		#define SCDC_STATUS_FLAGS_1 0x41

		#define SCDC_ERR_DET_0_L 0x50
		#define SCDC_ERR_DET_0_H 0x51
		#define SCDC_ERR_DET_1_L 0x52
		#define SCDC_ERR_DET_1_H 0x53
		#define SCDC_ERR_DET_2_L 0x54
		#define SCDC_ERR_DET_2_H 0x55
		#define SCDC_CHANNEL_VALID (1 << 7)

		#define SCDC_ERR_DET_CHECKSUM 0x56

		#define SCDC_TEST_CONFIG_0 0xc0
		#define SCDC_TEST_READ_REQUEST (1 << 7)
		#define SCDC_TEST_READ_REQUEST_DELAY(x) ((x) & 0x7f)

		#define SCDC_MANUFACTURER_IEEE_OUI 0xd0
		#define SCDC_MANUFACTURER_IEEE_OUI_SIZE 3

		#define SCDC_DEVICE_ID 0xd3
		#define SCDC_DEVICE_ID_SIZE 8

		#define SCDC_DEVICE_HARDWARE_REVISION 0xdb
		#define SCDC_GET_DEVICE_HARDWARE_REVISION_MAJOR(x) (((x) >> 4) & 0xf)
		#define SCDC_GET_DEVICE_HARDWARE_REVISION_MINOR(x) (((x) >> 0) & 0xf)

		#define SCDC_DEVICE_SOFTWARE_MAJOR_REVISION 0xdc
		#define SCDC_DEVICE_SOFTWARE_MINOR_REVISION 0xdd

		#define SCDC_MANUFACTURER_SPECIFIC 0xde
		#define SCDC_MANUFACTURER_SPECIFIC_SIZE 34

		ssize_t drm_scdc_read(struct i2c_adapter adapter, u8 offset, void buffer,
		size_t size);
		ssize_t drm_scdc_write(struct i2c_adapter *adapter, u8 offset,
		const void *buffer, size_t size);

		/**
		* drm_scdc_readb - read a single byte from SCDC
		* @adapter: I2C adapter
		* @offset: offset of register to read
		* @value: return location for the register value
		*
		* Reads a single byte from SCDC. This is a convenience wrapper around the
		* drm_scdc_read() function.
		*
		* Returns:
		* 0 on success or a negative error code on failure.
		*/
		static inline int drm_scdc_readb(struct i2c_adapter *adapter, u8 offset,
		u8 *value)
		{
		return drm_scdc_read(adapter, offset, value, sizeof(*value));
		}

		/**
		* drm_scdc_writeb - write a single byte to SCDC
		* @adapter: I2C adapter
		* @offset: offset of register to read
		* @value: return location for the register value
		*
		* Writes a single byte to SCDC. This is a convenience wrapper around the
		* drm_scdc_write() function.
		*
		* Returns:
		* 0 on success or a negative error code on failure.
		*/
		static inline int drm_scdc_writeb(struct i2c_adapter *adapter, u8 offset,
		u8 value)
		{
		return drm_scdc_write(adapter, offset, &value, sizeof(value));
		}

		#endif

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