diff options
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/hw_random/timeriomem-rng.c | 170 |
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; } |