^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * Microchip / Atmel ECC (I2C) driver.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright (c) 2017, Microchip Technology Inc.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) * Author: Tudor Ambarus <tudor.ambarus@microchip.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <linux/delay.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/device.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/err.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/errno.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/i2c.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <linux/of_device.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <linux/scatterlist.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #include <linux/workqueue.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) #include <crypto/internal/kpp.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) #include <crypto/ecdh.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #include <crypto/kpp.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) #include "atmel-i2c.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) static struct atmel_ecc_driver_data driver_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) * atmel_ecdh_ctx - transformation context
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) * @client : pointer to i2c client device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) * @fallback : used for unsupported curves or when user wants to use its own
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) * private key.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) * @public_key : generated when calling set_secret(). It's the responsibility
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) * of the user to not call set_secret() while
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) * generate_public_key() or compute_shared_secret() are in flight.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) * @curve_id : elliptic curve id
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) * @n_sz : size in bytes of the n prime
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) * @do_fallback: true when the device doesn't support the curve or when the user
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) * wants to use its own private key.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) struct atmel_ecdh_ctx {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) struct i2c_client *client;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) struct crypto_kpp *fallback;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) const u8 *public_key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) unsigned int curve_id;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) size_t n_sz;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) bool do_fallback;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) static void atmel_ecdh_done(struct atmel_i2c_work_data *work_data, void *areq,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) int status)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) struct kpp_request *req = areq;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) struct atmel_ecdh_ctx *ctx = work_data->ctx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) struct atmel_i2c_cmd *cmd = &work_data->cmd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) size_t copied, n_sz;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) if (status)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) goto free_work_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) /* might want less than we've got */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) n_sz = min_t(size_t, ctx->n_sz, req->dst_len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) /* copy the shared secret */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) copied = sg_copy_from_buffer(req->dst, sg_nents_for_len(req->dst, n_sz),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) &cmd->data[RSP_DATA_IDX], n_sz);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) if (copied != n_sz)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) status = -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) /* fall through */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) free_work_data:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) kfree_sensitive(work_data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) kpp_request_complete(req, status);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) static unsigned int atmel_ecdh_supported_curve(unsigned int curve_id)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) if (curve_id == ECC_CURVE_NIST_P256)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) return ATMEL_ECC_NIST_P256_N_SIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) * A random private key is generated and stored in the device. The device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) * returns the pair public key.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) static int atmel_ecdh_set_secret(struct crypto_kpp *tfm, const void *buf,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) unsigned int len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) struct atmel_ecdh_ctx *ctx = kpp_tfm_ctx(tfm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) struct atmel_i2c_cmd *cmd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) void *public_key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) struct ecdh params;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) int ret = -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) /* free the old public key, if any */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) kfree(ctx->public_key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) /* make sure you don't free the old public key twice */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) ctx->public_key = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) if (crypto_ecdh_decode_key(buf, len, ¶ms) < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) dev_err(&ctx->client->dev, "crypto_ecdh_decode_key failed\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) ctx->n_sz = atmel_ecdh_supported_curve(params.curve_id);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) if (!ctx->n_sz || params.key_size) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) /* fallback to ecdh software implementation */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) ctx->do_fallback = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) return crypto_kpp_set_secret(ctx->fallback, buf, len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) cmd = kmalloc(sizeof(*cmd), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) if (!cmd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) * The device only supports NIST P256 ECC keys. The public key size will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) * always be the same. Use a macro for the key size to avoid unnecessary
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) * computations.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) public_key = kmalloc(ATMEL_ECC_PUBKEY_SIZE, GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) if (!public_key)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) goto free_cmd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) ctx->do_fallback = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) ctx->curve_id = params.curve_id;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) atmel_i2c_init_genkey_cmd(cmd, DATA_SLOT_2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) ret = atmel_i2c_send_receive(ctx->client, cmd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) goto free_public_key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) /* save the public key */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) memcpy(public_key, &cmd->data[RSP_DATA_IDX], ATMEL_ECC_PUBKEY_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) ctx->public_key = public_key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) kfree(cmd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) free_public_key:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) kfree(public_key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) free_cmd:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) kfree(cmd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) static int atmel_ecdh_generate_public_key(struct kpp_request *req)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) struct crypto_kpp *tfm = crypto_kpp_reqtfm(req);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) struct atmel_ecdh_ctx *ctx = kpp_tfm_ctx(tfm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) size_t copied, nbytes;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) int ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) if (ctx->do_fallback) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) kpp_request_set_tfm(req, ctx->fallback);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) return crypto_kpp_generate_public_key(req);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) if (!ctx->public_key)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) /* might want less than we've got */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) nbytes = min_t(size_t, ATMEL_ECC_PUBKEY_SIZE, req->dst_len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) /* public key was saved at private key generation */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) copied = sg_copy_from_buffer(req->dst,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) sg_nents_for_len(req->dst, nbytes),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) ctx->public_key, nbytes);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) if (copied != nbytes)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) ret = -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) static int atmel_ecdh_compute_shared_secret(struct kpp_request *req)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) struct crypto_kpp *tfm = crypto_kpp_reqtfm(req);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) struct atmel_ecdh_ctx *ctx = kpp_tfm_ctx(tfm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) struct atmel_i2c_work_data *work_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) gfp_t gfp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) if (ctx->do_fallback) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) kpp_request_set_tfm(req, ctx->fallback);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) return crypto_kpp_compute_shared_secret(req);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) /* must have exactly two points to be on the curve */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) if (req->src_len != ATMEL_ECC_PUBKEY_SIZE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) gfp = (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ? GFP_KERNEL :
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) GFP_ATOMIC;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) work_data = kmalloc(sizeof(*work_data), gfp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) if (!work_data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) work_data->ctx = ctx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) work_data->client = ctx->client;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) ret = atmel_i2c_init_ecdh_cmd(&work_data->cmd, req->src);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) goto free_work_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) atmel_i2c_enqueue(work_data, atmel_ecdh_done, req);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) return -EINPROGRESS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) free_work_data:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) kfree(work_data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) static struct i2c_client *atmel_ecc_i2c_client_alloc(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) struct atmel_i2c_client_priv *i2c_priv, *min_i2c_priv = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) struct i2c_client *client = ERR_PTR(-ENODEV);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) int min_tfm_cnt = INT_MAX;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) int tfm_cnt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) spin_lock(&driver_data.i2c_list_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) if (list_empty(&driver_data.i2c_client_list)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) spin_unlock(&driver_data.i2c_list_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) return ERR_PTR(-ENODEV);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) list_for_each_entry(i2c_priv, &driver_data.i2c_client_list,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) i2c_client_list_node) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) tfm_cnt = atomic_read(&i2c_priv->tfm_count);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) if (tfm_cnt < min_tfm_cnt) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) min_tfm_cnt = tfm_cnt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) min_i2c_priv = i2c_priv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) if (!min_tfm_cnt)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) if (min_i2c_priv) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) atomic_inc(&min_i2c_priv->tfm_count);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) client = min_i2c_priv->client;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) spin_unlock(&driver_data.i2c_list_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) return client;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) static void atmel_ecc_i2c_client_free(struct i2c_client *client)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) struct atmel_i2c_client_priv *i2c_priv = i2c_get_clientdata(client);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) atomic_dec(&i2c_priv->tfm_count);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) static int atmel_ecdh_init_tfm(struct crypto_kpp *tfm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) const char *alg = kpp_alg_name(tfm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) struct crypto_kpp *fallback;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) struct atmel_ecdh_ctx *ctx = kpp_tfm_ctx(tfm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) ctx->client = atmel_ecc_i2c_client_alloc();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) if (IS_ERR(ctx->client)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) pr_err("tfm - i2c_client binding failed\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) return PTR_ERR(ctx->client);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) fallback = crypto_alloc_kpp(alg, 0, CRYPTO_ALG_NEED_FALLBACK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) if (IS_ERR(fallback)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) dev_err(&ctx->client->dev, "Failed to allocate transformation for '%s': %ld\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) alg, PTR_ERR(fallback));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) return PTR_ERR(fallback);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) crypto_kpp_set_flags(fallback, crypto_kpp_get_flags(tfm));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) ctx->fallback = fallback;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) static void atmel_ecdh_exit_tfm(struct crypto_kpp *tfm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) struct atmel_ecdh_ctx *ctx = kpp_tfm_ctx(tfm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) kfree(ctx->public_key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) crypto_free_kpp(ctx->fallback);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) atmel_ecc_i2c_client_free(ctx->client);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) static unsigned int atmel_ecdh_max_size(struct crypto_kpp *tfm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) struct atmel_ecdh_ctx *ctx = kpp_tfm_ctx(tfm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) if (ctx->fallback)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) return crypto_kpp_maxsize(ctx->fallback);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) * The device only supports NIST P256 ECC keys. The public key size will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) * always be the same. Use a macro for the key size to avoid unnecessary
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) * computations.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) return ATMEL_ECC_PUBKEY_SIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) static struct kpp_alg atmel_ecdh = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) .set_secret = atmel_ecdh_set_secret,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) .generate_public_key = atmel_ecdh_generate_public_key,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) .compute_shared_secret = atmel_ecdh_compute_shared_secret,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) .init = atmel_ecdh_init_tfm,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) .exit = atmel_ecdh_exit_tfm,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) .max_size = atmel_ecdh_max_size,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) .base = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) .cra_flags = CRYPTO_ALG_NEED_FALLBACK,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) .cra_name = "ecdh",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) .cra_driver_name = "atmel-ecdh",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) .cra_priority = ATMEL_ECC_PRIORITY,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) .cra_module = THIS_MODULE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) .cra_ctxsize = sizeof(struct atmel_ecdh_ctx),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) static int atmel_ecc_probe(struct i2c_client *client,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) const struct i2c_device_id *id)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) struct atmel_i2c_client_priv *i2c_priv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) ret = atmel_i2c_probe(client, id);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) i2c_priv = i2c_get_clientdata(client);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) spin_lock(&driver_data.i2c_list_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) list_add_tail(&i2c_priv->i2c_client_list_node,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) &driver_data.i2c_client_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) spin_unlock(&driver_data.i2c_list_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) ret = crypto_register_kpp(&atmel_ecdh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) if (ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) spin_lock(&driver_data.i2c_list_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) list_del(&i2c_priv->i2c_client_list_node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) spin_unlock(&driver_data.i2c_list_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) dev_err(&client->dev, "%s alg registration failed\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) atmel_ecdh.base.cra_driver_name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) dev_info(&client->dev, "atmel ecc algorithms registered in /proc/crypto\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) static int atmel_ecc_remove(struct i2c_client *client)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) struct atmel_i2c_client_priv *i2c_priv = i2c_get_clientdata(client);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) /* Return EBUSY if i2c client already allocated. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) if (atomic_read(&i2c_priv->tfm_count)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) dev_err(&client->dev, "Device is busy\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) return -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) crypto_unregister_kpp(&atmel_ecdh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) spin_lock(&driver_data.i2c_list_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) list_del(&i2c_priv->i2c_client_list_node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) spin_unlock(&driver_data.i2c_list_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) #ifdef CONFIG_OF
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) static const struct of_device_id atmel_ecc_dt_ids[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) .compatible = "atmel,atecc508a",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) }, {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) /* sentinel */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) MODULE_DEVICE_TABLE(of, atmel_ecc_dt_ids);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) static const struct i2c_device_id atmel_ecc_id[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) { "atecc508a", 0 },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) MODULE_DEVICE_TABLE(i2c, atmel_ecc_id);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) static struct i2c_driver atmel_ecc_driver = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) .driver = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) .name = "atmel-ecc",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) .of_match_table = of_match_ptr(atmel_ecc_dt_ids),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) .probe = atmel_ecc_probe,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) .remove = atmel_ecc_remove,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) .id_table = atmel_ecc_id,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) static int __init atmel_ecc_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) spin_lock_init(&driver_data.i2c_list_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) INIT_LIST_HEAD(&driver_data.i2c_client_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) return i2c_add_driver(&atmel_ecc_driver);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) static void __exit atmel_ecc_exit(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) flush_scheduled_work();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) i2c_del_driver(&atmel_ecc_driver);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) module_init(atmel_ecc_init);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) module_exit(atmel_ecc_exit);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) MODULE_AUTHOR("Tudor Ambarus <tudor.ambarus@microchip.com>");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) MODULE_DESCRIPTION("Microchip / Atmel ECC (I2C) driver");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) MODULE_LICENSE("GPL v2");
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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