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-rw-r--r--drivers/char/hw_random/Kconfig12
-rw-r--r--drivers/char/hw_random/Makefile1
-rw-r--r--drivers/char/hw_random/omap-rng.c14
-rw-r--r--drivers/char/hw_random/picoxcell-rng.c208
4 files changed, 227 insertions, 8 deletions
diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
index d31483c54883..beecd1cf9b99 100644
--- a/drivers/char/hw_random/Kconfig
+++ b/drivers/char/hw_random/Kconfig
@@ -198,3 +198,15 @@ config HW_RANDOM_NOMADIK
module will be called nomadik-rng.
If unsure, say Y.
+
+config HW_RANDOM_PICOXCELL
+ tristate "Picochip picoXcell true random number generator support"
+ depends on HW_RANDOM && ARCH_PICOXCELL && PICOXCELL_PC3X3
+ ---help---
+ This driver provides kernel-side support for the Random Number
+ Generator hardware found on Picochip PC3x3 and later devices.
+
+ To compile this driver as a module, choose M here: the
+ module will be called picoxcell-rng.
+
+ If unsure, say Y.
diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile
index 4273308aa1e3..3db4eb8b19c0 100644
--- a/drivers/char/hw_random/Makefile
+++ b/drivers/char/hw_random/Makefile
@@ -19,3 +19,4 @@ obj-$(CONFIG_HW_RANDOM_TX4939) += tx4939-rng.o
obj-$(CONFIG_HW_RANDOM_MXC_RNGA) += mxc-rnga.o
obj-$(CONFIG_HW_RANDOM_OCTEON) += octeon-rng.o
obj-$(CONFIG_HW_RANDOM_NOMADIK) += nomadik-rng.o
+obj-$(CONFIG_HW_RANDOM_PICOXCELL) += picoxcell-rng.o
diff --git a/drivers/char/hw_random/omap-rng.c b/drivers/char/hw_random/omap-rng.c
index 06aad0831c73..2cc755a64302 100644
--- a/drivers/char/hw_random/omap-rng.c
+++ b/drivers/char/hw_random/omap-rng.c
@@ -91,7 +91,7 @@ static struct hwrng omap_rng_ops = {
static int __devinit omap_rng_probe(struct platform_device *pdev)
{
- struct resource *res, *mem;
+ struct resource *res;
int ret;
/*
@@ -116,14 +116,12 @@ static int __devinit omap_rng_probe(struct platform_device *pdev)
if (!res)
return -ENOENT;
- mem = request_mem_region(res->start, resource_size(res),
- pdev->name);
- if (mem == NULL) {
+ if (!request_mem_region(res->start, resource_size(res), pdev->name)) {
ret = -EBUSY;
goto err_region;
}
- dev_set_drvdata(&pdev->dev, mem);
+ dev_set_drvdata(&pdev->dev, res);
rng_base = ioremap(res->start, resource_size(res));
if (!rng_base) {
ret = -ENOMEM;
@@ -146,7 +144,7 @@ err_register:
iounmap(rng_base);
rng_base = NULL;
err_ioremap:
- release_resource(mem);
+ release_mem_region(res->start, resource_size(res));
err_region:
if (cpu_is_omap24xx()) {
clk_disable(rng_ick);
@@ -157,7 +155,7 @@ err_region:
static int __exit omap_rng_remove(struct platform_device *pdev)
{
- struct resource *mem = dev_get_drvdata(&pdev->dev);
+ struct resource *res = dev_get_drvdata(&pdev->dev);
hwrng_unregister(&omap_rng_ops);
@@ -170,7 +168,7 @@ static int __exit omap_rng_remove(struct platform_device *pdev)
clk_put(rng_ick);
}
- release_resource(mem);
+ release_mem_region(res->start, resource_size(res));
rng_base = NULL;
return 0;
diff --git a/drivers/char/hw_random/picoxcell-rng.c b/drivers/char/hw_random/picoxcell-rng.c
new file mode 100644
index 000000000000..990d55a5e3e8
--- /dev/null
+++ b/drivers/char/hw_random/picoxcell-rng.c
@@ -0,0 +1,208 @@
+/*
+ * Copyright (c) 2010-2011 Picochip Ltd., Jamie Iles
+ *
+ * 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.
+ *
+ * All enquiries to support@picochip.com
+ */
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/hw_random.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#define DATA_REG_OFFSET 0x0200
+#define CSR_REG_OFFSET 0x0278
+#define CSR_OUT_EMPTY_MASK (1 << 24)
+#define CSR_FAULT_MASK (1 << 1)
+#define TRNG_BLOCK_RESET_MASK (1 << 0)
+#define TAI_REG_OFFSET 0x0380
+
+/*
+ * The maximum amount of time in microseconds to spend waiting for data if the
+ * core wants us to wait. The TRNG should generate 32 bits every 320ns so a
+ * timeout of 20us seems reasonable. The TRNG does builtin tests of the data
+ * for randomness so we can't always assume there is data present.
+ */
+#define PICO_TRNG_TIMEOUT 20
+
+static void __iomem *rng_base;
+static struct clk *rng_clk;
+struct device *rng_dev;
+
+static inline u32 picoxcell_trng_read_csr(void)
+{
+ return __raw_readl(rng_base + CSR_REG_OFFSET);
+}
+
+static inline bool picoxcell_trng_is_empty(void)
+{
+ return picoxcell_trng_read_csr() & CSR_OUT_EMPTY_MASK;
+}
+
+/*
+ * Take the random number generator out of reset and make sure the interrupts
+ * are masked. We shouldn't need to get large amounts of random bytes so just
+ * poll the status register. The hardware generates 32 bits every 320ns so we
+ * shouldn't have to wait long enough to warrant waiting for an IRQ.
+ */
+static void picoxcell_trng_start(void)
+{
+ __raw_writel(0, rng_base + TAI_REG_OFFSET);
+ __raw_writel(0, rng_base + CSR_REG_OFFSET);
+}
+
+static void picoxcell_trng_reset(void)
+{
+ __raw_writel(TRNG_BLOCK_RESET_MASK, rng_base + CSR_REG_OFFSET);
+ __raw_writel(TRNG_BLOCK_RESET_MASK, rng_base + TAI_REG_OFFSET);
+ picoxcell_trng_start();
+}
+
+/*
+ * Get some random data from the random number generator. The hw_random core
+ * layer provides us with locking.
+ */
+static int picoxcell_trng_read(struct hwrng *rng, void *buf, size_t max,
+ bool wait)
+{
+ int i;
+
+ /* Wait for some data to become available. */
+ for (i = 0; i < PICO_TRNG_TIMEOUT && picoxcell_trng_is_empty(); ++i) {
+ if (!wait)
+ return 0;
+
+ udelay(1);
+ }
+
+ if (picoxcell_trng_read_csr() & CSR_FAULT_MASK) {
+ dev_err(rng_dev, "fault detected, resetting TRNG\n");
+ picoxcell_trng_reset();
+ return -EIO;
+ }
+
+ if (i == PICO_TRNG_TIMEOUT)
+ return 0;
+
+ *(u32 *)buf = __raw_readl(rng_base + DATA_REG_OFFSET);
+ return sizeof(u32);
+}
+
+static struct hwrng picoxcell_trng = {
+ .name = "picoxcell",
+ .read = picoxcell_trng_read,
+};
+
+static int picoxcell_trng_probe(struct platform_device *pdev)
+{
+ int ret;
+ struct resource *mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+ if (!mem) {
+ dev_warn(&pdev->dev, "no memory resource\n");
+ return -ENOMEM;
+ }
+
+ if (!devm_request_mem_region(&pdev->dev, mem->start, resource_size(mem),
+ "picoxcell_trng")) {
+ dev_warn(&pdev->dev, "unable to request io mem\n");
+ return -EBUSY;
+ }
+
+ rng_base = devm_ioremap(&pdev->dev, mem->start, resource_size(mem));
+ if (!rng_base) {
+ dev_warn(&pdev->dev, "unable to remap io mem\n");
+ return -ENOMEM;
+ }
+
+ rng_clk = clk_get(&pdev->dev, NULL);
+ if (IS_ERR(rng_clk)) {
+ dev_warn(&pdev->dev, "no clk\n");
+ return PTR_ERR(rng_clk);
+ }
+
+ ret = clk_enable(rng_clk);
+ if (ret) {
+ dev_warn(&pdev->dev, "unable to enable clk\n");
+ goto err_enable;
+ }
+
+ picoxcell_trng_start();
+ ret = hwrng_register(&picoxcell_trng);
+ if (ret)
+ goto err_register;
+
+ rng_dev = &pdev->dev;
+ dev_info(&pdev->dev, "pixoxcell random number generator active\n");
+
+ return 0;
+
+err_register:
+ clk_disable(rng_clk);
+err_enable:
+ clk_put(rng_clk);
+
+ return ret;
+}
+
+static int __devexit picoxcell_trng_remove(struct platform_device *pdev)
+{
+ hwrng_unregister(&picoxcell_trng);
+ clk_disable(rng_clk);
+ clk_put(rng_clk);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int picoxcell_trng_suspend(struct device *dev)
+{
+ clk_disable(rng_clk);
+
+ return 0;
+}
+
+static int picoxcell_trng_resume(struct device *dev)
+{
+ return clk_enable(rng_clk);
+}
+
+static const struct dev_pm_ops picoxcell_trng_pm_ops = {
+ .suspend = picoxcell_trng_suspend,
+ .resume = picoxcell_trng_resume,
+};
+#endif /* CONFIG_PM */
+
+static struct platform_driver picoxcell_trng_driver = {
+ .probe = picoxcell_trng_probe,
+ .remove = __devexit_p(picoxcell_trng_remove),
+ .driver = {
+ .name = "picoxcell-trng",
+ .owner = THIS_MODULE,
+#ifdef CONFIG_PM
+ .pm = &picoxcell_trng_pm_ops,
+#endif /* CONFIG_PM */
+ },
+};
+
+static int __init picoxcell_trng_init(void)
+{
+ return platform_driver_register(&picoxcell_trng_driver);
+}
+module_init(picoxcell_trng_init);
+
+static void __exit picoxcell_trng_exit(void)
+{
+ platform_driver_unregister(&picoxcell_trng_driver);
+}
+module_exit(picoxcell_trng_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Jamie Iles");
+MODULE_DESCRIPTION("Picochip picoXcell TRNG driver");
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