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	This commit gives the secure world access to the I2C bus so it can
communicate with I2C slaves (typically those would be secure elements
like the NXP SE050).
A similar service implementation has been merged in linux:
c05210ab ("drivers: optee: allow op-tee to access devices on the i2c
bus")
Signed-off-by: Jorge Ramirez-Ortiz <jorge@foundries.io>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Etienne Carriere <etienne.carriere@linaro.org>
		
	
			
		
			
				
	
	
		
			91 lines
		
	
	
		
			1.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			91 lines
		
	
	
		
			1.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: BSD-2-Clause
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| /*
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|  * Copyright (c) 2020 Foundries.io Ltd
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|  */
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| 
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| #include <common.h>
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| #include <dm.h>
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| #include <i2c.h>
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| #include <tee.h>
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| #include "optee_msg.h"
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| #include "optee_private.h"
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| 
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| static int check_xfer_flags(struct udevice *chip, uint tee_flags)
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| {
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| 	uint flags;
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| 	int ret;
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| 
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| 	ret = i2c_get_chip_flags(chip, &flags);
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| 	if (ret)
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| 		return ret;
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| 
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| 	if (tee_flags & OPTEE_MSG_RPC_CMD_I2C_FLAGS_TEN_BIT) {
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| 		if (!(flags & DM_I2C_CHIP_10BIT))
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| 			return -EINVAL;
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| 	} else {
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| 		if (flags & DM_I2C_CHIP_10BIT)
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| 			return -EINVAL;
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| 	}
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| 
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| 	return 0;
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| }
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| 
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| void optee_suppl_cmd_i2c_transfer(struct optee_msg_arg *arg)
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| {
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| 	const u8 attr[] = {
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| 		OPTEE_MSG_ATTR_TYPE_VALUE_INPUT,
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| 		OPTEE_MSG_ATTR_TYPE_VALUE_INPUT,
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| 		OPTEE_MSG_ATTR_TYPE_RMEM_INOUT,
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| 		OPTEE_MSG_ATTR_TYPE_VALUE_OUTPUT,
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| 	};
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| 	struct udevice *chip_dev;
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| 	struct tee_shm *shm;
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| 	u8 *buf;
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| 	int ret;
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| 
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| 	if (arg->num_params != ARRAY_SIZE(attr) ||
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| 	    arg->params[0].attr != attr[0] ||
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| 	    arg->params[1].attr != attr[1] ||
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| 	    arg->params[2].attr != attr[2] ||
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| 	    arg->params[3].attr != attr[3]) {
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| 		goto bad;
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| 	}
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| 
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| 	shm = (struct tee_shm *)(unsigned long)arg->params[2].u.rmem.shm_ref;
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| 	buf = shm->addr;
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| 	if (!buf)
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| 		goto bad;
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| 
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| 	if (i2c_get_chip_for_busnum((int)arg->params[0].u.value.b,
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| 				    (int)arg->params[0].u.value.c,
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| 				    0, &chip_dev))
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| 		goto bad;
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| 
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| 	if (check_xfer_flags(chip_dev, arg->params[1].u.value.a))
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| 		goto bad;
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| 
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| 	switch (arg->params[0].u.value.a) {
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| 	case OPTEE_MSG_RPC_CMD_I2C_TRANSFER_RD:
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| 		ret = dm_i2c_read(chip_dev, 0, buf,
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| 				  (size_t)arg->params[2].u.rmem.size);
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| 		break;
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| 	case OPTEE_MSG_RPC_CMD_I2C_TRANSFER_WR:
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| 		ret = dm_i2c_write(chip_dev, 0, buf,
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| 				   (size_t)arg->params[2].u.rmem.size);
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| 		break;
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| 	default:
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| 		goto bad;
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| 	}
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| 
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| 	if (ret) {
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| 		arg->ret = TEE_ERROR_COMMUNICATION;
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| 	} else {
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| 		arg->params[3].u.value.a = arg->params[2].u.rmem.size;
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| 		arg->ret = TEE_SUCCESS;
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| 	}
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| 
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| 	return;
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| bad:
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| 	arg->ret = TEE_ERROR_BAD_PARAMETERS;
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| }
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