MIPS: hw_random: Add hardware RNG for Octeon SOCs.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

3 files changed, 161 insertions, 0 deletions

diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
index ce66a70184f7..87060266ef91 100644
--- a/drivers/char/hw_random/Kconfig
+++ b/drivers/char/hw_random/Kconfig
@@ -126,6 +126,19 @@ config HW_RANDOM_OMAP
 
           If unsure, say Y.
 
+config HW_RANDOM_OCTEON
+        tristate "Octeon Random Number Generator support"
+        depends on HW_RANDOM && CPU_CAVIUM_OCTEON
+        default HW_RANDOM
+        ---help---
+          This driver provides kernel-side support for the Random Number
+          Generator hardware found on Octeon processors.
+
+          To compile this driver as a module, choose M here: the
+          module will be called octeon-rng.
+
+          If unsure, say Y.
+
 config HW_RANDOM_PASEMI
         tristate "PA Semi HW Random Number Generator support"
         depends on HW_RANDOM && PPC_PASEMI
diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile
index 676828ba8123..5eeb1303f0d0 100644
--- a/drivers/char/hw_random/Makefile
+++ b/drivers/char/hw_random/Makefile
@@ -17,3 +17,4 @@ obj-$(CONFIG_HW_RANDOM_PASEMI) += pasemi-rng.o
 obj-$(CONFIG_HW_RANDOM_VIRTIO) += virtio-rng.o
 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
diff --git a/drivers/char/hw_random/octeon-rng.c b/drivers/char/hw_random/octeon-rng.c
new file mode 100644
index 000000000000..54b0d9ba65cf
--- /dev/null
+++ b/drivers/char/hw_random/octeon-rng.c
@@ -0,0 +1,147 @@
+/*
+ * Hardware Random Number Generator support for Cavium Networks
+ * Octeon processor family.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2009 Cavium Networks
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/device.h>
+#include <linux/hw_random.h>
+#include <linux/io.h>
+
+#include <asm/octeon/octeon.h>
+#include <asm/octeon/cvmx-rnm-defs.h>
+
+struct octeon_rng {
+        struct hwrng ops;
+        void __iomem *control_status;
+        void __iomem *result;
+};
+
+static int octeon_rng_init(struct hwrng *rng)
+{
+        union cvmx_rnm_ctl_status ctl;
+        struct octeon_rng *p = container_of(rng, struct octeon_rng, ops);
+
+        ctl.u64 = 0;
+        ctl.s.ent_en = 1; /* Enable the entropy source.  */
+        ctl.s.rng_en = 1; /* Enable the RNG hardware.  */
+        cvmx_write_csr((u64)p->control_status, ctl.u64);
+        return 0;
+}
+
+static void octeon_rng_cleanup(struct hwrng *rng)
+{
+        union cvmx_rnm_ctl_status ctl;
+        struct octeon_rng *p = container_of(rng, struct octeon_rng, ops);
+
+        ctl.u64 = 0;
+        /* Disable everything.  */
+        cvmx_write_csr((u64)p->control_status, ctl.u64);
+}
+
+static int octeon_rng_data_read(struct hwrng *rng, u32 *data)
+{
+        struct octeon_rng *p = container_of(rng, struct octeon_rng, ops);
+
+        *data = cvmx_read64_uint32((u64)p->result);
+        return sizeof(u32);
+}
+
+static int __devinit octeon_rng_probe(struct platform_device *pdev)
+{
+        struct resource *res_ports;
+        struct resource *res_result;
+        struct octeon_rng *rng;
+        int ret;
+        struct hwrng ops = {
+                .name = "octeon",
+                .init = octeon_rng_init,
+                .cleanup = octeon_rng_cleanup,
+                .data_read = octeon_rng_data_read
+        };
+
+        rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL);
+        if (!rng)
+                return -ENOMEM;
+
+        res_ports = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        if (!res_ports)
+                goto err_ports;
+
+        res_result = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+        if (!res_result)
+                goto err_ports;
+
+
+        rng->control_status = devm_ioremap_nocache(&pdev->dev,
+                                                   res_ports->start,
+                                                   sizeof(u64));
+        if (!rng->control_status)
+                goto err_ports;
+
+        rng->result = devm_ioremap_nocache(&pdev->dev,
+                                           res_result->start,
+                                           sizeof(u64));
+        if (!rng->result)
+                goto err_r;
+
+        rng->ops = ops;
+
+        dev_set_drvdata(&pdev->dev, &rng->ops);
+        ret = hwrng_register(&rng->ops);
+        if (ret)
+                goto err;
+
+        dev_info(&pdev->dev, "Octeon Random Number Generator\n");
+
+        return 0;
+err:
+        devm_iounmap(&pdev->dev, rng->control_status);
+err_r:
+        devm_iounmap(&pdev->dev, rng->result);
+err_ports:
+        devm_kfree(&pdev->dev, rng);
+        return -ENOENT;
+}
+
+static int __exit octeon_rng_remove(struct platform_device *pdev)
+{
+        struct hwrng *rng = dev_get_drvdata(&pdev->dev);
+
+        hwrng_unregister(rng);
+
+        return 0;
+}
+
+static struct platform_driver octeon_rng_driver = {
+        .driver = {
+                .name           = "octeon_rng",
+                .owner          = THIS_MODULE,
+        },
+        .probe          = octeon_rng_probe,
+        .remove         = __exit_p(octeon_rng_remove),
+};
+
+static int __init octeon_rng_mod_init(void)
+{
+        return platform_driver_register(&octeon_rng_driver);
+}
+
+static void __exit octeon_rng_mod_exit(void)
+{
+        platform_driver_unregister(&octeon_rng_driver);
+}
+
+module_init(octeon_rng_mod_init);
+module_exit(octeon_rng_mod_exit);
+
+MODULE_AUTHOR("David Daney");
+MODULE_LICENSE("GPL");