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authorAlexander Clouter <alex@digriz.org.uk>2013-03-31 17:34:50 +0100
committerHerbert Xu <herbert@gondor.apana.org.au>2013-04-25 21:01:45 +0800
commit1907da78bf6a3f74e5d030a4a4f6700ba0d0a234 (patch)
treeda0b0fc6f6f3327777976389d88843b1032e1d68 /drivers/char
parent57ae1b0532977b30184aaba04b6cafe0a284c21f (diff)
downloadvexpress-lsk-1907da78bf6a3f74e5d030a4a4f6700ba0d0a234.tar.gz
hwrng: timeriomem - update to support more than one device
timeriomem_rng only supports a single device instance. This patch enables multiple timeriomem_rng devices to coexist as well as adds some additional error checking. Signed-off-by: Alexander Clouter <alex@digriz.org.uk> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'drivers/char')
-rw-r--r--drivers/char/hw_random/timeriomem-rng.c170
1 files changed, 116 insertions, 54 deletions
diff --git a/drivers/char/hw_random/timeriomem-rng.c b/drivers/char/hw_random/timeriomem-rng.c
index 849db199c02..9dd2cadc31b 100644
--- a/drivers/char/hw_random/timeriomem-rng.c
+++ b/drivers/char/hw_random/timeriomem-rng.c
@@ -25,117 +25,179 @@
#include <linux/platform_device.h>
#include <linux/hw_random.h>
#include <linux/io.h>
+#include <linux/slab.h>
#include <linux/timeriomem-rng.h>
#include <linux/jiffies.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/completion.h>
-static struct timeriomem_rng_data *timeriomem_rng_data;
+struct timeriomem_rng_private_data {
+ void __iomem *io_base;
+ unsigned int expires;
+ unsigned int period;
+ unsigned int present:1;
-static void timeriomem_rng_trigger(unsigned long);
-static DEFINE_TIMER(timeriomem_rng_timer, timeriomem_rng_trigger, 0, 0);
+ struct timer_list timer;
+ struct completion completion;
+
+ struct hwrng timeriomem_rng_ops;
+};
+
+#define to_rng_priv(rng) \
+ ((struct timeriomem_rng_private_data *)rng->priv)
/*
* have data return 1, however return 0 if we have nothing
*/
static int timeriomem_rng_data_present(struct hwrng *rng, int wait)
{
- if (rng->priv == 0)
- return 1;
+ struct timeriomem_rng_private_data *priv = to_rng_priv(rng);
- if (!wait || timeriomem_rng_data->present)
- return timeriomem_rng_data->present;
+ if (!wait || priv->present)
+ return priv->present;
- wait_for_completion(&timeriomem_rng_data->completion);
+ wait_for_completion(&priv->completion);
return 1;
}
static int timeriomem_rng_data_read(struct hwrng *rng, u32 *data)
{
+ struct timeriomem_rng_private_data *priv = to_rng_priv(rng);
unsigned long cur;
s32 delay;
- *data = readl(timeriomem_rng_data->address);
+ *data = readl(priv->io_base);
- if (rng->priv != 0) {
- cur = jiffies;
+ cur = jiffies;
- delay = cur - timeriomem_rng_timer.expires;
- delay = rng->priv - (delay % rng->priv);
+ delay = cur - priv->expires;
+ delay = priv->period - (delay % priv->period);
- timeriomem_rng_timer.expires = cur + delay;
- timeriomem_rng_data->present = 0;
+ priv->expires = cur + delay;
+ priv->present = 0;
- init_completion(&timeriomem_rng_data->completion);
- add_timer(&timeriomem_rng_timer);
- }
+ INIT_COMPLETION(priv->completion);
+ mod_timer(&priv->timer, priv->expires);
return 4;
}
-static void timeriomem_rng_trigger(unsigned long dummy)
+static void timeriomem_rng_trigger(unsigned long data)
{
- timeriomem_rng_data->present = 1;
- complete(&timeriomem_rng_data->completion);
-}
+ struct timeriomem_rng_private_data *priv
+ = (struct timeriomem_rng_private_data *)data;
-static struct hwrng timeriomem_rng_ops = {
- .name = "timeriomem",
- .data_present = timeriomem_rng_data_present,
- .data_read = timeriomem_rng_data_read,
- .priv = 0,
-};
+ priv->present = 1;
+ complete(&priv->completion);
+}
static int timeriomem_rng_probe(struct platform_device *pdev)
{
+ struct timeriomem_rng_data *pdata = pdev->dev.platform_data;
+ struct timeriomem_rng_private_data *priv;
struct resource *res;
- int ret;
+ int err = 0;
+ int period;
- res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!pdata) {
+ dev_err(&pdev->dev, "timeriomem_rng_data is missing\n");
+ return -EINVAL;
+ }
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res)
- return -ENOENT;
+ return -ENXIO;
- timeriomem_rng_data = pdev->dev.platform_data;
+ if (res->start % 4 != 0 || resource_size(res) != 4) {
+ dev_err(&pdev->dev,
+ "address must be four bytes wide and aligned\n");
+ return -EINVAL;
+ }
- timeriomem_rng_data->address = ioremap(res->start, resource_size(res));
- if (!timeriomem_rng_data->address)
- return -EIO;
+ /* Allocate memory for the device structure (and zero it) */
+ priv = kzalloc(sizeof(struct timeriomem_rng_private_data), GFP_KERNEL);
+ if (!priv) {
+ dev_err(&pdev->dev, "failed to allocate device structure.\n");
+ return -ENOMEM;
+ }
+
+ platform_set_drvdata(pdev, priv);
- if (timeriomem_rng_data->period != 0
- && usecs_to_jiffies(timeriomem_rng_data->period) > 0) {
- timeriomem_rng_timer.expires = jiffies;
+ period = pdata->period;
- timeriomem_rng_ops.priv = usecs_to_jiffies(
- timeriomem_rng_data->period);
+ priv->period = usecs_to_jiffies(period);
+ if (priv->period < 1) {
+ dev_err(&pdev->dev, "period is less than one jiffy\n");
+ err = -EINVAL;
+ goto out_free;
}
- timeriomem_rng_data->present = 1;
- ret = hwrng_register(&timeriomem_rng_ops);
- if (ret)
- goto failed;
+ priv->expires = jiffies;
+ priv->present = 1;
+
+ init_completion(&priv->completion);
+ complete(&priv->completion);
+
+ setup_timer(&priv->timer, timeriomem_rng_trigger, (unsigned long)priv);
+
+ priv->timeriomem_rng_ops.name = dev_name(&pdev->dev);
+ priv->timeriomem_rng_ops.data_present = timeriomem_rng_data_present;
+ priv->timeriomem_rng_ops.data_read = timeriomem_rng_data_read;
+ priv->timeriomem_rng_ops.priv = (unsigned long)priv;
+
+ if (!request_mem_region(res->start, resource_size(res),
+ dev_name(&pdev->dev))) {
+ dev_err(&pdev->dev, "request_mem_region failed\n");
+ err = -EBUSY;
+ goto out_timer;
+ }
+
+ priv->io_base = ioremap(res->start, resource_size(res));
+ if (priv->io_base == NULL) {
+ dev_err(&pdev->dev, "ioremap failed\n");
+ err = -EIO;
+ goto out_release_io;
+ }
+
+ err = hwrng_register(&priv->timeriomem_rng_ops);
+ if (err) {
+ dev_err(&pdev->dev, "problem registering\n");
+ goto out;
+ }
dev_info(&pdev->dev, "32bits from 0x%p @ %dus\n",
- timeriomem_rng_data->address,
- timeriomem_rng_data->period);
+ priv->io_base, period);
return 0;
-failed:
- dev_err(&pdev->dev, "problem registering\n");
- iounmap(timeriomem_rng_data->address);
-
- return ret;
+out:
+ iounmap(priv->io_base);
+out_release_io:
+ release_mem_region(res->start, resource_size(res));
+out_timer:
+ del_timer_sync(&priv->timer);
+out_free:
+ platform_set_drvdata(pdev, NULL);
+ kfree(priv);
+ return err;
}
static int timeriomem_rng_remove(struct platform_device *pdev)
{
- del_timer_sync(&timeriomem_rng_timer);
- hwrng_unregister(&timeriomem_rng_ops);
+ struct timeriomem_rng_private_data *priv = platform_get_drvdata(pdev);
+ struct resource *res;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+ hwrng_unregister(&priv->timeriomem_rng_ops);
- iounmap(timeriomem_rng_data->address);
+ del_timer_sync(&priv->timer);
+ iounmap(priv->io_base);
+ release_mem_region(res->start, resource_size(res));
+ platform_set_drvdata(pdev, NULL);
+ kfree(priv);
return 0;
}