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63 lines
1.4 KiB
63 lines
1.4 KiB
/* |
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* Copyright (c) 2022, Commonwealth Scientific and Industrial Research |
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* Organisation (CSIRO) ABN 41 687 119 230. |
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* |
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* SPDX-License-Identifier: Apache-2.0 |
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*/ |
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#define DT_DRV_COMPAT zephyr_bt_hci_entropy |
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#include <drivers/entropy.h> |
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#include <bluetooth/hci.h> |
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#include <string.h> |
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static int entropy_bt_init(const struct device *dev) |
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{ |
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/* Nothing to do */ |
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return 0; |
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} |
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static int entropy_bt_get_entropy(const struct device *dev, |
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uint8_t *buffer, uint16_t length) |
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{ |
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struct bt_hci_rp_le_rand *rp; |
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struct net_buf *rsp; |
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int req, ret; |
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if (!bt_is_ready()) { |
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return -EAGAIN; |
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} |
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while (length > 0) { |
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/* Number of bytes to fill on this iteration */ |
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req = MIN(length, sizeof(rp->rand)); |
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/* Request the next 8 bytes over HCI */ |
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ret = bt_hci_cmd_send_sync(BT_HCI_OP_LE_RAND, NULL, &rsp); |
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if (ret) { |
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return ret; |
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} |
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/* Copy random data into buffer */ |
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rp = (void *)rsp->data; |
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memcpy(buffer, rp->rand, req); |
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net_buf_unref(rsp); |
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buffer += req; |
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length -= req; |
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} |
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return 0; |
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} |
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/* HCI commands cannot be run from an interrupt context */ |
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static const struct entropy_driver_api entropy_bt_api = { |
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.get_entropy = entropy_bt_get_entropy, |
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.get_entropy_isr = NULL |
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}; |
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#define ENTROPY_BT_HCI_INIT(inst) \ |
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DEVICE_DT_INST_DEFINE(inst, entropy_bt_init, \ |
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NULL, NULL, NULL, \ |
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PRE_KERNEL_1, \ |
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CONFIG_KERNEL_INIT_PRIORITY_DEVICE, \ |
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&entropy_bt_api); |
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DT_INST_FOREACH_STATUS_OKAY(ENTROPY_BT_HCI_INIT)
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