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path: root/drivers/char/hw_random/timeriomem-rng.c
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Diffstat (limited to 'drivers/char/hw_random/timeriomem-rng.c')
-rw-r--r--drivers/char/hw_random/timeriomem-rng.c53
1 files changed, 16 insertions, 37 deletions
diff --git a/drivers/char/hw_random/timeriomem-rng.c b/drivers/char/hw_random/timeriomem-rng.c
index 03ff5483d865..e61f06393209 100644
--- a/drivers/char/hw_random/timeriomem-rng.c
+++ b/drivers/char/hw_random/timeriomem-rng.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* drivers/char/hw_random/timeriomem-rng.c
*
@@ -7,10 +8,6 @@
* Copyright 2005 (c) MontaVista Software, Inc.
* Author: Deepak Saxena <dsaxena@plexity.net>
*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
* Overview:
* This driver is useful for platforms that have an IO range that provides
* periodic random data from a single IO memory address. All the platform
@@ -53,13 +50,6 @@ static int timeriomem_rng_read(struct hwrng *hwrng, void *data,
int period_us = ktime_to_us(priv->period);
/*
- * The RNG provides 32-bits per read. Ensure there is enough space for
- * at minimum one read.
- */
- if (max < sizeof(u32))
- return 0;
-
- /*
* There may not have been enough time for new data to be generated
* since the last request. If the caller doesn't want to wait, let them
* bail out. Otherwise, wait for the completion. If the new data has
@@ -79,7 +69,7 @@ static int timeriomem_rng_read(struct hwrng *hwrng, void *data,
*/
if (retval > 0)
usleep_range(period_us,
- period_us + min(1, period_us / 100));
+ period_us + max(1, period_us / 100));
*(u32 *)data = readl(priv->io_base);
retval += sizeof(u32);
@@ -123,16 +113,6 @@ static int timeriomem_rng_probe(struct platform_device *pdev)
return -EINVAL;
}
- res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- if (!res)
- return -ENXIO;
-
- if (res->start % 4 != 0 || resource_size(res) != 4) {
- dev_err(&pdev->dev,
- "address must be four bytes wide and aligned\n");
- return -EINVAL;
- }
-
/* Allocate memory for the device structure (and zero it) */
priv = devm_kzalloc(&pdev->dev,
sizeof(struct timeriomem_rng_private), GFP_KERNEL);
@@ -141,6 +121,16 @@ static int timeriomem_rng_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, priv);
+ priv->io_base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+ if (IS_ERR(priv->io_base))
+ return PTR_ERR(priv->io_base);
+
+ if (res->start % 4 != 0 || resource_size(res) < 4) {
+ dev_err(&pdev->dev,
+ "address must be at least four bytes wide and 32-bit aligned\n");
+ return -EINVAL;
+ }
+
if (pdev->dev.of_node) {
int i;
@@ -155,31 +145,23 @@ static int timeriomem_rng_probe(struct platform_device *pdev)
if (!of_property_read_u32(pdev->dev.of_node,
"quality", &i))
priv->rng_ops.quality = i;
- else
- priv->rng_ops.quality = 0;
} else {
period = pdata->period;
priv->rng_ops.quality = pdata->quality;
}
- priv->period = ns_to_ktime(period * NSEC_PER_USEC);
+ priv->period = us_to_ktime(period);
init_completion(&priv->completion);
- hrtimer_init(&priv->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
- priv->timer.function = timeriomem_rng_trigger;
+ hrtimer_setup(&priv->timer, timeriomem_rng_trigger, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
priv->rng_ops.name = dev_name(&pdev->dev);
priv->rng_ops.read = timeriomem_rng_read;
- priv->io_base = devm_ioremap_resource(&pdev->dev, res);
- if (IS_ERR(priv->io_base)) {
- return PTR_ERR(priv->io_base);
- }
-
/* Assume random data is already available. */
priv->present = 1;
complete(&priv->completion);
- err = hwrng_register(&priv->rng_ops);
+ err = devm_hwrng_register(&pdev->dev, &priv->rng_ops);
if (err) {
dev_err(&pdev->dev, "problem registering\n");
return err;
@@ -191,14 +173,11 @@ static int timeriomem_rng_probe(struct platform_device *pdev)
return 0;
}
-static int timeriomem_rng_remove(struct platform_device *pdev)
+static void timeriomem_rng_remove(struct platform_device *pdev)
{
struct timeriomem_rng_private *priv = platform_get_drvdata(pdev);
- hwrng_unregister(&priv->rng_ops);
hrtimer_cancel(&priv->timer);
-
- return 0;
}
static const struct of_device_id timeriomem_rng_match[] = {