Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/crypto/atmel-i2c.c b/drivers/crypto/atmel-i2c.c
new file mode 100644
index 0000000..1d33559
--- /dev/null
+++ b/drivers/crypto/atmel-i2c.c
@@ -0,0 +1,376 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Microchip / Atmel ECC (I2C) driver.
+ *
+ * Copyright (c) 2017, Microchip Technology Inc.
+ * Author: Tudor Ambarus <tudor.ambarus@microchip.com>
+ */
+
+#include <linux/bitrev.h>
+#include <linux/crc16.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/scatterlist.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+#include "atmel-i2c.h"
+
+static const struct {
+ u8 value;
+ const char *error_text;
+} error_list[] = {
+ { 0x01, "CheckMac or Verify miscompare" },
+ { 0x03, "Parse Error" },
+ { 0x05, "ECC Fault" },
+ { 0x0F, "Execution Error" },
+ { 0xEE, "Watchdog about to expire" },
+ { 0xFF, "CRC or other communication error" },
+};
+
+/**
+ * atmel_i2c_checksum() - Generate 16-bit CRC as required by ATMEL ECC.
+ * CRC16 verification of the count, opcode, param1, param2 and data bytes.
+ * The checksum is saved in little-endian format in the least significant
+ * two bytes of the command. CRC polynomial is 0x8005 and the initial register
+ * value should be zero.
+ *
+ * @cmd : structure used for communicating with the device.
+ */
+static void atmel_i2c_checksum(struct atmel_i2c_cmd *cmd)
+{
+ u8 *data = &cmd->count;
+ size_t len = cmd->count - CRC_SIZE;
+ __le16 *__crc16 = (__le16 *)(data + len);
+
+ *__crc16 = cpu_to_le16(bitrev16(crc16(0, data, len)));
+}
+
+void atmel_i2c_init_read_cmd(struct atmel_i2c_cmd *cmd)
+{
+ cmd->word_addr = COMMAND;
+ cmd->opcode = OPCODE_READ;
+ /*
+ * Read the word from Configuration zone that contains the lock bytes
+ * (UserExtra, Selector, LockValue, LockConfig).
+ */
+ cmd->param1 = CONFIG_ZONE;
+ cmd->param2 = cpu_to_le16(DEVICE_LOCK_ADDR);
+ cmd->count = READ_COUNT;
+
+ atmel_i2c_checksum(cmd);
+
+ cmd->msecs = MAX_EXEC_TIME_READ;
+ cmd->rxsize = READ_RSP_SIZE;
+}
+EXPORT_SYMBOL(atmel_i2c_init_read_cmd);
+
+void atmel_i2c_init_random_cmd(struct atmel_i2c_cmd *cmd)
+{
+ cmd->word_addr = COMMAND;
+ cmd->opcode = OPCODE_RANDOM;
+ cmd->param1 = 0;
+ cmd->param2 = 0;
+ cmd->count = RANDOM_COUNT;
+
+ atmel_i2c_checksum(cmd);
+
+ cmd->msecs = MAX_EXEC_TIME_RANDOM;
+ cmd->rxsize = RANDOM_RSP_SIZE;
+}
+EXPORT_SYMBOL(atmel_i2c_init_random_cmd);
+
+void atmel_i2c_init_genkey_cmd(struct atmel_i2c_cmd *cmd, u16 keyid)
+{
+ cmd->word_addr = COMMAND;
+ cmd->count = GENKEY_COUNT;
+ cmd->opcode = OPCODE_GENKEY;
+ cmd->param1 = GENKEY_MODE_PRIVATE;
+ /* a random private key will be generated and stored in slot keyID */
+ cmd->param2 = cpu_to_le16(keyid);
+
+ atmel_i2c_checksum(cmd);
+
+ cmd->msecs = MAX_EXEC_TIME_GENKEY;
+ cmd->rxsize = GENKEY_RSP_SIZE;
+}
+EXPORT_SYMBOL(atmel_i2c_init_genkey_cmd);
+
+int atmel_i2c_init_ecdh_cmd(struct atmel_i2c_cmd *cmd,
+ struct scatterlist *pubkey)
+{
+ size_t copied;
+
+ cmd->word_addr = COMMAND;
+ cmd->count = ECDH_COUNT;
+ cmd->opcode = OPCODE_ECDH;
+ cmd->param1 = ECDH_PREFIX_MODE;
+ /* private key slot */
+ cmd->param2 = cpu_to_le16(DATA_SLOT_2);
+
+ /*
+ * The device only supports NIST P256 ECC keys. The public key size will
+ * always be the same. Use a macro for the key size to avoid unnecessary
+ * computations.
+ */
+ copied = sg_copy_to_buffer(pubkey,
+ sg_nents_for_len(pubkey,
+ ATMEL_ECC_PUBKEY_SIZE),
+ cmd->data, ATMEL_ECC_PUBKEY_SIZE);
+ if (copied != ATMEL_ECC_PUBKEY_SIZE)
+ return -EINVAL;
+
+ atmel_i2c_checksum(cmd);
+
+ cmd->msecs = MAX_EXEC_TIME_ECDH;
+ cmd->rxsize = ECDH_RSP_SIZE;
+
+ return 0;
+}
+EXPORT_SYMBOL(atmel_i2c_init_ecdh_cmd);
+
+/*
+ * After wake and after execution of a command, there will be error, status, or
+ * result bytes in the device's output register that can be retrieved by the
+ * system. When the length of that group is four bytes, the codes returned are
+ * detailed in error_list.
+ */
+static int atmel_i2c_status(struct device *dev, u8 *status)
+{
+ size_t err_list_len = ARRAY_SIZE(error_list);
+ int i;
+ u8 err_id = status[1];
+
+ if (*status != STATUS_SIZE)
+ return 0;
+
+ if (err_id == STATUS_WAKE_SUCCESSFUL || err_id == STATUS_NOERR)
+ return 0;
+
+ for (i = 0; i < err_list_len; i++)
+ if (error_list[i].value == err_id)
+ break;
+
+ /* if err_id is not in the error_list then ignore it */
+ if (i != err_list_len) {
+ dev_err(dev, "%02x: %s:\n", err_id, error_list[i].error_text);
+ return err_id;
+ }
+
+ return 0;
+}
+
+static int atmel_i2c_wakeup(struct i2c_client *client)
+{
+ struct atmel_i2c_client_priv *i2c_priv = i2c_get_clientdata(client);
+ u8 status[STATUS_RSP_SIZE];
+ int ret;
+
+ /*
+ * The device ignores any levels or transitions on the SCL pin when the
+ * device is idle, asleep or during waking up. Don't check for error
+ * when waking up the device.
+ */
+ i2c_master_send(client, i2c_priv->wake_token, i2c_priv->wake_token_sz);
+
+ /*
+ * Wait to wake the device. Typical execution times for ecdh and genkey
+ * are around tens of milliseconds. Delta is chosen to 50 microseconds.
+ */
+ usleep_range(TWHI_MIN, TWHI_MAX);
+
+ ret = i2c_master_recv(client, status, STATUS_SIZE);
+ if (ret < 0)
+ return ret;
+
+ return atmel_i2c_status(&client->dev, status);
+}
+
+static int atmel_i2c_sleep(struct i2c_client *client)
+{
+ u8 sleep = SLEEP_TOKEN;
+
+ return i2c_master_send(client, &sleep, 1);
+}
+
+/*
+ * atmel_i2c_send_receive() - send a command to the device and receive its
+ * response.
+ * @client: i2c client device
+ * @cmd : structure used to communicate with the device
+ *
+ * After the device receives a Wake token, a watchdog counter starts within the
+ * device. After the watchdog timer expires, the device enters sleep mode
+ * regardless of whether some I/O transmission or command execution is in
+ * progress. If a command is attempted when insufficient time remains prior to
+ * watchdog timer execution, the device will return the watchdog timeout error
+ * code without attempting to execute the command. There is no way to reset the
+ * counter other than to put the device into sleep or idle mode and then
+ * wake it up again.
+ */
+int atmel_i2c_send_receive(struct i2c_client *client, struct atmel_i2c_cmd *cmd)
+{
+ struct atmel_i2c_client_priv *i2c_priv = i2c_get_clientdata(client);
+ int ret;
+
+ mutex_lock(&i2c_priv->lock);
+
+ ret = atmel_i2c_wakeup(client);
+ if (ret)
+ goto err;
+
+ /* send the command */
+ ret = i2c_master_send(client, (u8 *)cmd, cmd->count + WORD_ADDR_SIZE);
+ if (ret < 0)
+ goto err;
+
+ /* delay the appropriate amount of time for command to execute */
+ msleep(cmd->msecs);
+
+ /* receive the response */
+ ret = i2c_master_recv(client, cmd->data, cmd->rxsize);
+ if (ret < 0)
+ goto err;
+
+ /* put the device into low-power mode */
+ ret = atmel_i2c_sleep(client);
+ if (ret < 0)
+ goto err;
+
+ mutex_unlock(&i2c_priv->lock);
+ return atmel_i2c_status(&client->dev, cmd->data);
+err:
+ mutex_unlock(&i2c_priv->lock);
+ return ret;
+}
+EXPORT_SYMBOL(atmel_i2c_send_receive);
+
+static void atmel_i2c_work_handler(struct work_struct *work)
+{
+ struct atmel_i2c_work_data *work_data =
+ container_of(work, struct atmel_i2c_work_data, work);
+ struct atmel_i2c_cmd *cmd = &work_data->cmd;
+ struct i2c_client *client = work_data->client;
+ int status;
+
+ status = atmel_i2c_send_receive(client, cmd);
+ work_data->cbk(work_data, work_data->areq, status);
+}
+
+void atmel_i2c_enqueue(struct atmel_i2c_work_data *work_data,
+ void (*cbk)(struct atmel_i2c_work_data *work_data,
+ void *areq, int status),
+ void *areq)
+{
+ work_data->cbk = (void *)cbk;
+ work_data->areq = areq;
+
+ INIT_WORK(&work_data->work, atmel_i2c_work_handler);
+ schedule_work(&work_data->work);
+}
+EXPORT_SYMBOL(atmel_i2c_enqueue);
+
+static inline size_t atmel_i2c_wake_token_sz(u32 bus_clk_rate)
+{
+ u32 no_of_bits = DIV_ROUND_UP(TWLO_USEC * bus_clk_rate, USEC_PER_SEC);
+
+ /* return the size of the wake_token in bytes */
+ return DIV_ROUND_UP(no_of_bits, 8);
+}
+
+static int device_sanity_check(struct i2c_client *client)
+{
+ struct atmel_i2c_cmd *cmd;
+ int ret;
+
+ cmd = kmalloc(sizeof(*cmd), GFP_KERNEL);
+ if (!cmd)
+ return -ENOMEM;
+
+ atmel_i2c_init_read_cmd(cmd);
+
+ ret = atmel_i2c_send_receive(client, cmd);
+ if (ret)
+ goto free_cmd;
+
+ /*
+ * It is vital that the Configuration, Data and OTP zones be locked
+ * prior to release into the field of the system containing the device.
+ * Failure to lock these zones may permit modification of any secret
+ * keys and may lead to other security problems.
+ */
+ if (cmd->data[LOCK_CONFIG_IDX] || cmd->data[LOCK_VALUE_IDX]) {
+ dev_err(&client->dev, "Configuration or Data and OTP zones are unlocked!\n");
+ ret = -ENOTSUPP;
+ }
+
+ /* fall through */
+free_cmd:
+ kfree(cmd);
+ return ret;
+}
+
+int atmel_i2c_probe(struct i2c_client *client, const struct i2c_device_id *id)
+{
+ struct atmel_i2c_client_priv *i2c_priv;
+ struct device *dev = &client->dev;
+ int ret;
+ u32 bus_clk_rate;
+
+ if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+ dev_err(dev, "I2C_FUNC_I2C not supported\n");
+ return -ENODEV;
+ }
+
+ bus_clk_rate = i2c_acpi_find_bus_speed(&client->adapter->dev);
+ if (!bus_clk_rate) {
+ ret = device_property_read_u32(&client->adapter->dev,
+ "clock-frequency", &bus_clk_rate);
+ if (ret) {
+ dev_err(dev, "failed to read clock-frequency property\n");
+ return ret;
+ }
+ }
+
+ if (bus_clk_rate > 1000000L) {
+ dev_err(dev, "%d exceeds maximum supported clock frequency (1MHz)\n",
+ bus_clk_rate);
+ return -EINVAL;
+ }
+
+ i2c_priv = devm_kmalloc(dev, sizeof(*i2c_priv), GFP_KERNEL);
+ if (!i2c_priv)
+ return -ENOMEM;
+
+ i2c_priv->client = client;
+ mutex_init(&i2c_priv->lock);
+
+ /*
+ * WAKE_TOKEN_MAX_SIZE was calculated for the maximum bus_clk_rate -
+ * 1MHz. The previous bus_clk_rate check ensures us that wake_token_sz
+ * will always be smaller than or equal to WAKE_TOKEN_MAX_SIZE.
+ */
+ i2c_priv->wake_token_sz = atmel_i2c_wake_token_sz(bus_clk_rate);
+
+ memset(i2c_priv->wake_token, 0, sizeof(i2c_priv->wake_token));
+
+ atomic_set(&i2c_priv->tfm_count, 0);
+
+ i2c_set_clientdata(client, i2c_priv);
+
+ ret = device_sanity_check(client);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+EXPORT_SYMBOL(atmel_i2c_probe);
+
+MODULE_AUTHOR("Tudor Ambarus <tudor.ambarus@microchip.com>");
+MODULE_DESCRIPTION("Microchip / Atmel ECC (I2C) driver");
+MODULE_LICENSE("GPL v2");