59 lines
1.5 KiB
C
59 lines
1.5 KiB
C
/*
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* Copyright (c) 2017 Intel Corporation
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#include <i2c.h>
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#include <string.h>
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#include <syscall_handler.h>
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_SYSCALL_HANDLER(i2c_configure, dev, dev_config)
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{
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_SYSCALL_DRIVER_I2C(dev, configure);
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return _impl_i2c_configure((struct device *)dev, dev_config);
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}
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static u32_t copy_msgs_and_transfer(struct device *dev,
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const struct i2c_msg *msgs,
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u8_t num_msgs,
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u16_t addr,
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void *ssf)
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{
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struct i2c_msg copy[num_msgs];
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u8_t i;
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/* Use a local copy to avoid switcheroo attacks. */
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memcpy(copy, msgs, num_msgs * sizeof(*msgs));
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/* Validate the buffers in each message struct. Read options require
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* that the target buffer be writable
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*/
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for (i = 0; i < num_msgs; i++) {
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_SYSCALL_MEMORY(copy[i].buf, copy[i].len,
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copy[i].flags & I2C_MSG_READ);
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}
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return _impl_i2c_transfer(dev, copy, num_msgs, addr);
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}
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_SYSCALL_HANDLER(i2c_transfer, dev, msgs, num_msgs, addr)
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{
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_SYSCALL_OBJ(dev, K_OBJ_DRIVER_I2C);
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/* copy_msgs_and_transfer() will allocate a copy on the stack using
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* VLA, so ensure this won't blow the stack. Most functions defined
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* in i2c.h use only a handful of messages, so up to 32 messages
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* should be more than sufficient.
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*/
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_SYSCALL_VERIFY(num_msgs >= 1 && num_msgs < 32);
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/* We need to be able to read the overall array of messages */
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_SYSCALL_MEMORY_ARRAY_READ(msgs, num_msgs, sizeof(struct i2c_msg));
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return copy_msgs_and_transfer((struct device *)dev,
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(struct i2c_msg *)msgs,
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(u8_t)num_msgs, (u16_t)addr,
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ssf);
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}
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