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path: root/drivers/char/hw_random/mxc-rnga.c
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Diffstat (limited to 'drivers/char/hw_random/mxc-rnga.c')
-rw-r--r--drivers/char/hw_random/mxc-rnga.c163
1 files changed, 67 insertions, 96 deletions
diff --git a/drivers/char/hw_random/mxc-rnga.c b/drivers/char/hw_random/mxc-rnga.c
index 187c6be80f4..6a86b6f56af 100644
--- a/drivers/char/hw_random/mxc-rnga.c
+++ b/drivers/char/hw_random/mxc-rnga.c
@@ -24,6 +24,7 @@
#include <linux/ioport.h>
#include <linux/platform_device.h>
#include <linux/hw_random.h>
+#include <linux/delay.h>
#include <linux/io.h>
/* RNGA Registers */
@@ -58,38 +59,47 @@
#define RNGA_STATUS_LAST_READ_STATUS 0x00000002
#define RNGA_STATUS_SECURITY_VIOLATION 0x00000001
-static struct platform_device *rng_dev;
+struct mxc_rng {
+ struct device *dev;
+ struct hwrng rng;
+ void __iomem *mem;
+ struct clk *clk;
+};
-static int mxc_rnga_data_present(struct hwrng *rng)
+static int mxc_rnga_data_present(struct hwrng *rng, int wait)
{
- int level;
- void __iomem *rng_base = (void __iomem *)rng->priv;
-
- /* how many random numbers is in FIFO? [0-16] */
- level = ((__raw_readl(rng_base + RNGA_STATUS) &
- RNGA_STATUS_LEVEL_MASK) >> 8);
-
- return level > 0 ? 1 : 0;
+ int i;
+ struct mxc_rng *mxc_rng = container_of(rng, struct mxc_rng, rng);
+
+ for (i = 0; i < 20; i++) {
+ /* how many random numbers are in FIFO? [0-16] */
+ int level = (__raw_readl(mxc_rng->mem + RNGA_STATUS) &
+ RNGA_STATUS_LEVEL_MASK) >> 8;
+ if (level || !wait)
+ return !!level;
+ udelay(10);
+ }
+ return 0;
}
static int mxc_rnga_data_read(struct hwrng *rng, u32 * data)
{
int err;
u32 ctrl;
- void __iomem *rng_base = (void __iomem *)rng->priv;
+ struct mxc_rng *mxc_rng = container_of(rng, struct mxc_rng, rng);
/* retrieve a random number from FIFO */
- *data = __raw_readl(rng_base + RNGA_OUTPUT_FIFO);
+ *data = __raw_readl(mxc_rng->mem + RNGA_OUTPUT_FIFO);
/* some error while reading this random number? */
- err = __raw_readl(rng_base + RNGA_STATUS) & RNGA_STATUS_ERROR_INT;
+ err = __raw_readl(mxc_rng->mem + RNGA_STATUS) & RNGA_STATUS_ERROR_INT;
/* if error: clear error interrupt, but doesn't return random number */
if (err) {
- dev_dbg(&rng_dev->dev, "Error while reading random number!\n");
- ctrl = __raw_readl(rng_base + RNGA_CONTROL);
+ dev_dbg(mxc_rng->dev, "Error while reading random number!\n");
+ ctrl = __raw_readl(mxc_rng->mem + RNGA_CONTROL);
__raw_writel(ctrl | RNGA_CONTROL_CLEAR_INT,
- rng_base + RNGA_CONTROL);
+ mxc_rng->mem + RNGA_CONTROL);
return 0;
} else
return 4;
@@ -98,22 +108,22 @@ static int mxc_rnga_data_read(struct hwrng *rng, u32 * data)
static int mxc_rnga_init(struct hwrng *rng)
{
u32 ctrl, osc;
- void __iomem *rng_base = (void __iomem *)rng->priv;
+ struct mxc_rng *mxc_rng = container_of(rng, struct mxc_rng, rng);
/* wake up */
- ctrl = __raw_readl(rng_base + RNGA_CONTROL);
- __raw_writel(ctrl & ~RNGA_CONTROL_SLEEP, rng_base + RNGA_CONTROL);
+ ctrl = __raw_readl(mxc_rng->mem + RNGA_CONTROL);
+ __raw_writel(ctrl & ~RNGA_CONTROL_SLEEP, mxc_rng->mem + RNGA_CONTROL);
/* verify if oscillator is working */
- osc = __raw_readl(rng_base + RNGA_STATUS);
+ osc = __raw_readl(mxc_rng->mem + RNGA_STATUS);
if (osc & RNGA_STATUS_OSC_DEAD) {
- dev_err(&rng_dev->dev, "RNGA Oscillator is dead!\n");
+ dev_err(mxc_rng->dev, "RNGA Oscillator is dead!\n");
return -ENODEV;
}
/* go running */
- ctrl = __raw_readl(rng_base + RNGA_CONTROL);
- __raw_writel(ctrl | RNGA_CONTROL_GO, rng_base + RNGA_CONTROL);
+ ctrl = __raw_readl(mxc_rng->mem + RNGA_CONTROL);
+ __raw_writel(ctrl | RNGA_CONTROL_GO, mxc_rng->mem + RNGA_CONTROL);
return 0;
}
@@ -121,83 +131,62 @@ static int mxc_rnga_init(struct hwrng *rng)
static void mxc_rnga_cleanup(struct hwrng *rng)
{
u32 ctrl;
- void __iomem *rng_base = (void __iomem *)rng->priv;
+ struct mxc_rng *mxc_rng = container_of(rng, struct mxc_rng, rng);
- ctrl = __raw_readl(rng_base + RNGA_CONTROL);
+ ctrl = __raw_readl(mxc_rng->mem + RNGA_CONTROL);
/* stop rnga */
- __raw_writel(ctrl & ~RNGA_CONTROL_GO, rng_base + RNGA_CONTROL);
+ __raw_writel(ctrl & ~RNGA_CONTROL_GO, mxc_rng->mem + RNGA_CONTROL);
}
-static struct hwrng mxc_rnga = {
- .name = "mxc-rnga",
- .init = mxc_rnga_init,
- .cleanup = mxc_rnga_cleanup,
- .data_present = mxc_rnga_data_present,
- .data_read = mxc_rnga_data_read
-};
-
static int __init mxc_rnga_probe(struct platform_device *pdev)
{
int err = -ENODEV;
- struct clk *clk;
- struct resource *res, *mem;
- void __iomem *rng_base = NULL;
-
- if (rng_dev)
- return -EBUSY;
-
- clk = clk_get(&pdev->dev, "rng");
- if (IS_ERR(clk)) {
+ struct resource *res;
+ struct mxc_rng *mxc_rng;
+
+ mxc_rng = devm_kzalloc(&pdev->dev, sizeof(struct mxc_rng),
+ GFP_KERNEL);
+ if (!mxc_rng)
+ return -ENOMEM;
+
+ mxc_rng->dev = &pdev->dev;
+ mxc_rng->rng.name = "mxc-rnga";
+ mxc_rng->rng.init = mxc_rnga_init;
+ mxc_rng->rng.cleanup = mxc_rnga_cleanup,
+ mxc_rng->rng.data_present = mxc_rnga_data_present,
+ mxc_rng->rng.data_read = mxc_rnga_data_read,
+
+ mxc_rng->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(mxc_rng->clk)) {
dev_err(&pdev->dev, "Could not get rng_clk!\n");
- err = PTR_ERR(clk);
+ err = PTR_ERR(mxc_rng->clk);
goto out;
}
- clk_enable(clk);
+ err = clk_prepare_enable(mxc_rng->clk);
+ if (err)
+ goto out;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- if (!res) {
- err = -ENOENT;
- goto err_region;
- }
-
- mem = request_mem_region(res->start, resource_size(res), pdev->name);
- if (mem == NULL) {
- err = -EBUSY;
- goto err_region;
- }
-
- rng_base = ioremap(res->start, resource_size(res));
- if (!rng_base) {
- err = -ENOMEM;
+ mxc_rng->mem = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(mxc_rng->mem)) {
+ err = PTR_ERR(mxc_rng->mem);
goto err_ioremap;
}
- mxc_rnga.priv = (unsigned long)rng_base;
-
- err = hwrng_register(&mxc_rnga);
+ err = hwrng_register(&mxc_rng->rng);
if (err) {
dev_err(&pdev->dev, "MXC RNGA registering failed (%d)\n", err);
- goto err_register;
+ goto err_ioremap;
}
- rng_dev = pdev;
-
dev_info(&pdev->dev, "MXC RNGA Registered.\n");
return 0;
-err_register:
- iounmap(rng_base);
- rng_base = NULL;
-
err_ioremap:
- release_mem_region(res->start, resource_size(res));
-
-err_region:
- clk_disable(clk);
- clk_put(clk);
+ clk_disable_unprepare(mxc_rng->clk);
out:
return err;
@@ -205,18 +194,11 @@ out:
static int __exit mxc_rnga_remove(struct platform_device *pdev)
{
- struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- void __iomem *rng_base = (void __iomem *)mxc_rnga.priv;
- struct clk *clk = clk_get(&pdev->dev, "rng");
-
- hwrng_unregister(&mxc_rnga);
+ struct mxc_rng *mxc_rng = platform_get_drvdata(pdev);
- iounmap(rng_base);
+ hwrng_unregister(&mxc_rng->rng);
- release_mem_region(res->start, resource_size(res));
-
- clk_disable(clk);
- clk_put(clk);
+ clk_disable_unprepare(mxc_rng->clk);
return 0;
}
@@ -229,18 +211,7 @@ static struct platform_driver mxc_rnga_driver = {
.remove = __exit_p(mxc_rnga_remove),
};
-static int __init mod_init(void)
-{
- return platform_driver_probe(&mxc_rnga_driver, mxc_rnga_probe);
-}
-
-static void __exit mod_exit(void)
-{
- platform_driver_unregister(&mxc_rnga_driver);
-}
-
-module_init(mod_init);
-module_exit(mod_exit);
+module_platform_driver_probe(mxc_rnga_driver, mxc_rnga_probe);
MODULE_AUTHOR("Freescale Semiconductor, Inc.");
MODULE_DESCRIPTION("H/W RNGA driver for i.MX");