Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 170 insertions, 0 deletions

diff --git a/drivers/crypto/atmel-sha204a.c b/drivers/crypto/atmel-sha204a.c
new file mode 100644
index 000000000..c96c14e7d
--- /dev/null
+++ b/drivers/crypto/atmel-sha204a.c
@@ -0,0 +1,170 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Microchip / Atmel SHA204A (I2C) driver.
+ *
+ * Copyright (c) 2019 Linaro, Ltd. <ard.biesheuvel@linaro.org>
+ */
+
+#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 void atmel_sha204a_rng_done(struct atmel_i2c_work_data *work_data,
+				   void *areq, int status)
+{
+	struct atmel_i2c_client_priv *i2c_priv = work_data->ctx;
+	struct hwrng *rng = areq;
+
+	if (status)
+		dev_warn_ratelimited(&i2c_priv->client->dev,
+				     "i2c transaction failed (%d)\n",
+				     status);
+
+	rng->priv = (unsigned long)work_data;
+	atomic_dec(&i2c_priv->tfm_count);
+}
+
+static int atmel_sha204a_rng_read_nonblocking(struct hwrng *rng, void *data,
+					      size_t max)
+{
+	struct atmel_i2c_client_priv *i2c_priv;
+	struct atmel_i2c_work_data *work_data;
+
+	i2c_priv = container_of(rng, struct atmel_i2c_client_priv, hwrng);
+
+	/* keep maximum 1 asynchronous read in flight at any time */
+	if (!atomic_add_unless(&i2c_priv->tfm_count, 1, 1))
+		return 0;
+
+	if (rng->priv) {
+		work_data = (struct atmel_i2c_work_data *)rng->priv;
+		max = min(sizeof(work_data->cmd.data), max);
+		memcpy(data, &work_data->cmd.data, max);
+		rng->priv = 0;
+	} else {
+		work_data = kmalloc(sizeof(*work_data), GFP_ATOMIC);
+		if (!work_data)
+			return -ENOMEM;
+
+		work_data->ctx = i2c_priv;
+		work_data->client = i2c_priv->client;
+
+		max = 0;
+	}
+
+	atmel_i2c_init_random_cmd(&work_data->cmd);
+	atmel_i2c_enqueue(work_data, atmel_sha204a_rng_done, rng);
+
+	return max;
+}
+
+static int atmel_sha204a_rng_read(struct hwrng *rng, void *data, size_t max,
+				  bool wait)
+{
+	struct atmel_i2c_client_priv *i2c_priv;
+	struct atmel_i2c_cmd cmd;
+	int ret;
+
+	if (!wait)
+		return atmel_sha204a_rng_read_nonblocking(rng, data, max);
+
+	i2c_priv = container_of(rng, struct atmel_i2c_client_priv, hwrng);
+
+	atmel_i2c_init_random_cmd(&cmd);
+
+	ret = atmel_i2c_send_receive(i2c_priv->client, &cmd);
+	if (ret)
+		return ret;
+
+	max = min(sizeof(cmd.data), max);
+	memcpy(data, cmd.data, max);
+
+	return max;
+}
+
+static int atmel_sha204a_probe(struct i2c_client *client,
+			       const struct i2c_device_id *id)
+{
+	struct atmel_i2c_client_priv *i2c_priv;
+	int ret;
+
+	ret = atmel_i2c_probe(client, id);
+	if (ret)
+		return ret;
+
+	i2c_priv = i2c_get_clientdata(client);
+
+	memset(&i2c_priv->hwrng, 0, sizeof(i2c_priv->hwrng));
+
+	i2c_priv->hwrng.name = dev_name(&client->dev);
+	i2c_priv->hwrng.read = atmel_sha204a_rng_read;
+	i2c_priv->hwrng.quality = 1024;
+
+	ret = devm_hwrng_register(&client->dev, &i2c_priv->hwrng);
+	if (ret)
+		dev_warn(&client->dev, "failed to register RNG (%d)\n", ret);
+
+	return ret;
+}
+
+static int atmel_sha204a_remove(struct i2c_client *client)
+{
+	struct atmel_i2c_client_priv *i2c_priv = i2c_get_clientdata(client);
+
+	if (atomic_read(&i2c_priv->tfm_count)) {
+		dev_err(&client->dev, "Device is busy\n");
+		return -EBUSY;
+	}
+
+	if (i2c_priv->hwrng.priv)
+		kfree((void *)i2c_priv->hwrng.priv);
+
+	return 0;
+}
+
+static const struct of_device_id atmel_sha204a_dt_ids[] = {
+	{ .compatible = "atmel,atsha204a", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, atmel_sha204a_dt_ids);
+
+static const struct i2c_device_id atmel_sha204a_id[] = {
+	{ "atsha204a", 0 },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(i2c, atmel_sha204a_id);
+
+static struct i2c_driver atmel_sha204a_driver = {
+	.probe			= atmel_sha204a_probe,
+	.remove			= atmel_sha204a_remove,
+	.id_table		= atmel_sha204a_id,
+
+	.driver.name		= "atmel-sha204a",
+	.driver.of_match_table	= of_match_ptr(atmel_sha204a_dt_ids),
+};
+
+static int __init atmel_sha204a_init(void)
+{
+	return i2c_add_driver(&atmel_sha204a_driver);
+}
+
+static void __exit atmel_sha204a_exit(void)
+{
+	flush_scheduled_work();
+	i2c_del_driver(&atmel_sha204a_driver);
+}
+
+module_init(atmel_sha204a_init);
+module_exit(atmel_sha204a_exit);
+
+MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
+MODULE_LICENSE("GPL v2");