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linux/drivers/crypto/atmel-sha204a.c
Uwe Kleine-König ed5c2f5fd1 i2c: Make remove callback return void
The value returned by an i2c driver's remove function is mostly ignored.
(Only an error message is printed if the value is non-zero that the
error is ignored.)

So change the prototype of the remove function to return no value. This
way driver authors are not tempted to assume that passing an error to
the upper layer is a good idea. All drivers are adapted accordingly.
There is no intended change of behaviour, all callbacks were prepared to
return 0 before.

Reviewed-by: Peter Senna Tschudin <peter.senna@gmail.com>
Reviewed-by: Jeremy Kerr <jk@codeconstruct.com.au>
Reviewed-by: Benjamin Mugnier <benjamin.mugnier@foss.st.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Crt Mori <cmo@melexis.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Marek Behún <kabel@kernel.org> # for leds-turris-omnia
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Petr Machata <petrm@nvidia.com> # for mlxsw
Reviewed-by: Maximilian Luz <luzmaximilian@gmail.com> # for surface3_power
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> # for bmc150-accel-i2c + kxcjk-1013
Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> # for media/* + staging/media/*
Acked-by: Miguel Ojeda <ojeda@kernel.org> # for auxdisplay/ht16k33 + auxdisplay/lcd2s
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com> # for versaclock5
Reviewed-by: Ajay Gupta <ajayg@nvidia.com> # for ucsi_ccg
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> # for iio
Acked-by: Peter Rosin <peda@axentia.se> # for i2c-mux-*, max9860
Acked-by: Adrien Grassein <adrien.grassein@gmail.com> # for lontium-lt8912b
Reviewed-by: Jean Delvare <jdelvare@suse.de> # for hwmon, i2c-core and i2c/muxes
Acked-by: Corey Minyard <cminyard@mvista.com> # for IPMI
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com> # for drivers/power
Acked-by: Krzysztof Hałasa <khalasa@piap.pl>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
2022-08-16 12:46:26 +02:00

170 lines
4.0 KiB
C

// 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 void 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_emerg(&client->dev, "Device is busy, will remove it anyhow\n");
return;
}
kfree((void *)i2c_priv->hwrng.priv);
}
static const struct of_device_id atmel_sha204a_dt_ids[] = {
{ .compatible = "atmel,atsha204", },
{ .compatible = "atmel,atsha204a", },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, atmel_sha204a_dt_ids);
static const struct i2c_device_id atmel_sha204a_id[] = {
{ "atsha204", 0 },
{ "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)
{
atmel_i2c_flush_queue();
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");