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>

diff --git a/drivers/char/hw_random/timeriomem-rng.c b/drivers/char/hw_random/timeriomem-rng.c
index 849db19..9dd2cad 100644 (file)
--- 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;
 }

diff --git a/include/linux/timeriomem-rng.h b/include/linux/timeriomem-rng.h
index 3e08a1c..46eb27d 100644 (file)
--- a/include/linux/timeriomem-rng.h
+++ b/include/linux/timeriomem-rng.h
@@ -8,12 +8,7 @@
  * published by the Free Software Foundation.
  */
 
-#include <linux/completion.h>
-
 struct timeriomem_rng_data {
-       struct completion       completion;
-       unsigned int            present:1;
-
        void __iomem            *address;
 
        /* measures in usecs */