On Tue, 2011-06-21 at 08:19 -0400, Josh Boyer wrote:
> Various PowerPC 4xx SoCs contain a TRNG embedded in the Security function.
> This adds a device driver for that TRNG.
>
> Signed-off-by: Josh Boyer <jwbo...@linux.vnet.ibm.com>
Looks good.
Acked-by: Matt Mackall <m...@selenic.com>
> ---
> drivers/char/hw_random/Kconfig | 12 +++
> drivers/char/hw_random/Makefile | 1 +
> drivers/char/hw_random/ppc4xx-rng.c | 156
> +++++++++++++++++++++++++++++++++++
> 3 files changed, 169 insertions(+), 0 deletions(-)
> create mode 100644 drivers/char/hw_random/ppc4xx-rng.c
>
> diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
> index a60043b..1d2ebc7 100644
> --- a/drivers/char/hw_random/Kconfig
> +++ b/drivers/char/hw_random/Kconfig
> @@ -210,3 +210,15 @@ config HW_RANDOM_PICOXCELL
> module will be called picoxcell-rng.
>
> If unsure, say Y.
> +
> +config HW_RANDOM_PPC4XX
> + tristate "PowerPC 4xx generic true random number generator support"
> + depends on HW_RANDOM && PPC && 4xx
> + ---help---
> + This driver provides the kernel-side support for the TRNG hardware
> + found in the security function of some PowerPC 4xx SoCs.
> +
> + To compile this driver as a module, choose M here: the
> + module will be called ppc4xx-rng.
> +
> + If unsure, say N.
> diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile
> index 3db4eb8..c88f244 100644
> --- a/drivers/char/hw_random/Makefile
> +++ b/drivers/char/hw_random/Makefile
> @@ -20,3 +20,4 @@ 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
> +obj-$(CONFIG_HW_RANDOM_PPC4XX) += ppc4xx-rng.o
> diff --git a/drivers/char/hw_random/ppc4xx-rng.c
> b/drivers/char/hw_random/ppc4xx-rng.c
> new file mode 100644
> index 0000000..b8afa6a
> --- /dev/null
> +++ b/drivers/char/hw_random/ppc4xx-rng.c
> @@ -0,0 +1,156 @@
> +/*
> + * Generic PowerPC 44x RNG driver
> + *
> + * Copyright 2011 IBM Corporation
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License as published by the
> + * Free Software Foundation; version 2 of the License.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/platform_device.h>
> +#include <linux/hw_random.h>
> +#include <linux/delay.h>
> +#include <linux/of_platform.h>
> +#include <asm/io.h>
> +
> +#define PPC4XX_TRNG_DEV_CTRL 0x60080
> +
> +#define PPC4XX_TRNGE 0x00020000
> +#define PPC4XX_TRNG_CTRL 0x0008
> +#define PPC4XX_TRNG_CTRL_DALM 0x20
> +#define PPC4XX_TRNG_STAT 0x0004
> +#define PPC4XX_TRNG_STAT_B 0x1
> +#define PPC4XX_TRNG_DATA 0x0000
> +
> +#define MODULE_NAME "ppc4xx_rng"
> +
> +static int ppc4xx_rng_data_present(struct hwrng *rng, int wait)
> +{
> + void __iomem *rng_regs = (void __iomem *) rng->priv;
> + int busy, i, present = 0;
> +
> + for (i = 0; i < 20; i++) {
> + busy = (in_le32(rng_regs + PPC4XX_TRNG_STAT) &
> PPC4XX_TRNG_STAT_B);
> + if (!busy || !wait) {
> + present = 1;
> + break;
> + }
> + udelay(10);
> + }
> + return present;
> +}
> +
> +static int ppc4xx_rng_data_read(struct hwrng *rng, u32 *data)
> +{
> + void __iomem *rng_regs = (void __iomem *) rng->priv;
> + *data = in_le32(rng_regs + PPC4XX_TRNG_DATA);
> + return 4;
> +}
> +
> +static int ppc4xx_rng_enable(int enable)
> +{
> + struct device_node *ctrl;
> + void __iomem *ctrl_reg;
> + int err = 0;
> + u32 val;
> +
> + /* Find the main crypto device node and map it to turn the TRNG on */
> + ctrl = of_find_compatible_node(NULL, NULL, "amcc,ppc4xx-crypto");
> + if (!ctrl)
> + return -ENODEV;
> +
> + ctrl_reg = of_iomap(ctrl, 0);
> + if (!ctrl_reg) {
> + err = -ENODEV;
> + goto out;
> + }
> +
> + val = in_le32(ctrl_reg + PPC4XX_TRNG_DEV_CTRL);
> +
> + if (enable)
> + val |= PPC4XX_TRNGE;
> + else
> + val = val & ~PPC4XX_TRNGE;
> +
> + out_le32(ctrl_reg + PPC4XX_TRNG_DEV_CTRL, val);
> + iounmap(ctrl_reg);
> +
> +out:
> + of_node_put(ctrl);
> +
> + return err;
> +}
> +
> +static struct hwrng ppc4xx_rng = {
> + .name = MODULE_NAME,
> + .data_present = ppc4xx_rng_data_present,
> + .data_read = ppc4xx_rng_data_read,
> +};
> +
> +static int __devinit ppc4xx_rng_probe(struct platform_device *dev)
> +{
> + void __iomem *rng_regs;
> + int err = 0;
> +
> + rng_regs = of_iomap(dev->dev.of_node, 0);
> + if (!rng_regs)
> + return -ENODEV;
> +
> + err = ppc4xx_rng_enable(1);
> + if (err)
> + return err;
> +
> + out_le32(rng_regs + PPC4XX_TRNG_CTRL, PPC4XX_TRNG_CTRL_DALM);
> + ppc4xx_rng.priv = (unsigned long) rng_regs;
> +
> + err = hwrng_register(&ppc4xx_rng);
> +
> + return err;
> +}
> +
> +static int __devexit ppc4xx_rng_remove(struct platform_device *dev)
> +{
> + void __iomem *rng_regs = (void __iomem *) ppc4xx_rng.priv;
> +
> + hwrng_unregister(&ppc4xx_rng);
> + ppc4xx_rng_enable(0);
> + iounmap(rng_regs);
> +
> + return 0;
> +}
> +
> +static struct of_device_id ppc4xx_rng_match[] = {
> + { .compatible = "ppc4xx-rng", },
> + { .compatible = "amcc,ppc460ex-rng", },
> + { .compatible = "amcc,ppc440epx-rng", },
> + {},
> +};
> +
> +static struct platform_driver ppc4xx_rng_driver = {
> + .driver = {
> + .name = MODULE_NAME,
> + .owner = THIS_MODULE,
> + .of_match_table = ppc4xx_rng_match,
> + },
> + .probe = ppc4xx_rng_probe,
> + .remove = ppc4xx_rng_remove,
> +};
> +
> +static int __init ppc4xx_rng_init(void)
> +{
> + return platform_driver_register(&ppc4xx_rng_driver);
> +}
> +module_init(ppc4xx_rng_init);
> +
> +static void __exit ppc4xx_rng_exit(void)
> +{
> + platform_driver_unregister(&ppc4xx_rng_driver);
> +}
> +module_exit(ppc4xx_rng_exit);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("Josh Boyer <jwbo...@linux.vnet.ibm.com>");
> +MODULE_DESCRIPTION("HW RNG driver for PPC 4xx processors");
--
Mathematics is the supreme nostalgia of our time.
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev
