diff options
Diffstat (limited to 'drivers/char/hw_random')
| -rw-r--r-- | drivers/char/hw_random/Kconfig | 12 | ||||
| -rw-r--r-- | drivers/char/hw_random/Makefile | 1 | ||||
| -rw-r--r-- | drivers/char/hw_random/trng4xx.c | 336 |
3 files changed, 349 insertions, 0 deletions
diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig index 87060266ef9..9cfbb282e0c 100644 --- a/drivers/char/hw_random/Kconfig +++ b/drivers/char/hw_random/Kconfig @@ -186,3 +186,15 @@ config HW_RANDOM_MXC_RNGA module will be called mxc-rnga. If unsure, say Y. +config HW_RANDOM_TRNG4xx + tristate "AMCC 4xx TRNG True Random Number Generator support" + depends on HW_RANDOM && PPC + default HW_RANDOM + ---help--- + This driver provides kernel-side support for the Random Number + Generator hardware found on AMCC 4XX. + + To compile this driver as a module, choose M here: the + module will be called trng4xx. + + If unsure, say Y. diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile index 5eeb1303f0d..252902d42c8 100644 --- a/drivers/char/hw_random/Makefile +++ b/drivers/char/hw_random/Makefile @@ -18,3 +18,4 @@ 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 +obj-$(CONFIG_HW_RANDOM_TRNG4xx) += trng4xx.o diff --git a/drivers/char/hw_random/trng4xx.c b/drivers/char/hw_random/trng4xx.c new file mode 100644 index 00000000000..ece45e74aa1 --- /dev/null +++ b/drivers/char/hw_random/trng4xx.c @@ -0,0 +1,336 @@ +/** + * + * Copyright (c) 2008 Loc Ho <spulijala@amcc.com> + * + * 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; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * Detail Description: + * This file AMCC TRNG offload Linux device driver + * + * @file trng4xx.c + * + * + */ +#include <linux/version.h> +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/platform_device.h> +#include <linux/of_platform.h> +#include <linux/hw_random.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <crypto/trng4xx.h> + +#define TRNG4XX_VER_STR "0.1" +#define TRNG4XX_HDR "TRNG4XX: " + +/* #define TRNG4XX_DEBUG */ + +#if !defined(TRNG4XX_DEBUG) +# define TRNG4XX_LOG(fmt, ...) +#else +# define TRNG4XX_LOG(fmt, ...) \ + do { \ + printk(KERN_INFO TRNG4XX_HDR fmt "\n", ##__VA_ARGS__); \ +} while(0); +#endif + +struct trng4xx_dev { + struct resource res; + u32 irq; + volatile char __iomem *csr; + struct semaphore access_prot; + u32 datum; +}; + +struct hal_config { + struct of_device *ofdev; +}; + +static struct trng4xx_dev trng4xx_dev; + +static irqreturn_t trng4xx_irq_handler(int irq, void *id); +static void trng4xx_chk_overflow(void); + +int trng4xx_config_set(struct hal_config *cfg) +{ + struct device_node *rng_np = cfg->ofdev->node; + int rc = 0; + + rc = of_address_to_resource(rng_np, 0, &trng4xx_dev.res); + if (rc) + return -ENODEV; + + trng4xx_dev.csr = ioremap(trng4xx_dev.res.start, + trng4xx_dev.res.end - + trng4xx_dev.res.start + 1); + if (trng4xx_dev.csr == NULL) { + printk(KERN_ERR "unable to ioremap 0x%02X_%08X size %d\n", + (u32) (trng4xx_dev.res.start >> 32), + (u32) trng4xx_dev.res.start, + (u32) (trng4xx_dev.res.end - + trng4xx_dev.res.start + 1)); + return -ENOMEM; + } + + TRNG4XX_LOG("TRNG1 0x%02X_%08X size %d\n", + (u32) (trng4xx_dev.res.start >> 32), + (u32) trng4xx_dev.res.start, + (u32) (trng4xx_dev.res.end - + trng4xx_dev.res.start + 1)); + + trng4xx_dev.irq = of_irq_to_resource(rng_np, 0, NULL); + + if (trng4xx_dev.irq == NO_IRQ) { + /* Un-map CSR */ + iounmap(trng4xx_dev.csr); + trng4xx_dev.csr = NULL; + return -EINVAL; + } + + return 0; +} + +int trng4xx_pka_config_clear(void) +{ + iounmap(trng4xx_dev.csr); + return 0; +} + +inline int trng4xx_hw_read32(u32 reg_addr, u32 *data_val) +{ + *data_val = in_be32((unsigned __iomem *) + (trng4xx_dev.csr + reg_addr)); + return 0; +} + +inline int trng4xx_hw_write32(u32 reg_addr, u32 data_val) +{ + out_be32((unsigned __iomem *) (trng4xx_dev.csr + reg_addr), + data_val); + return 0; +} + +int trng4xx_hw_init(void) +{ + int rc; + + rc = request_irq(trng4xx_dev.irq, trng4xx_irq_handler, + 0, "TRNG", NULL); + if (rc != 0) { + printk(KERN_ERR "failed to register interrupt IRQ %d\n", + trng4xx_dev.irq); + return rc; + } + return 0; +} + +int trng4xx_hw_deinit(void) +{ + free_irq(trng4xx_dev.irq, NULL); + return 0; +} + +static irqreturn_t trng4xx_irq_handler(int irq, void *id) +{ + /* TRNG Alarm Counter overflow */ + trng4xx_chk_overflow(); + return IRQ_HANDLED; +} + +/** + * TRNG Functions + * + */ +static void trng4xx_chk_overflow(void) +{ + /* TRNG Alarm Counter overflow */ + int rc; + u32 val; + struct trng4xx_cfg { + u32 ring1_delay_sel :3; + u32 ring2_delay_sel :3; + u32 reset_cnt :6; + } __attribute__((packed)); + + + rc = trng4xx_hw_write32(TRNG4XX_ALARMCNT_ADDR, val); + if (rc != 0) + return; + + if (val > 128) { + struct trng4xx_cfg *trng4xx_cfg; + + /* Alarm count is half, reset it */ + rc = trng4xx_hw_read32(TRNG4XX_CFG_ADDR, &val); + if (rc != 0) + return; + trng4xx_cfg = (struct trng4xx_cfg *) &val; + ++trng4xx_cfg->ring1_delay_sel; + trng4xx_cfg->ring2_delay_sel = + (~trng4xx_cfg->ring1_delay_sel) & 0x07; + + rc = trng4xx_hw_write32(TRNG4XX_CFG_ADDR, val); + if (rc != 0) + return; + trng4xx_hw_write32(TRNG4XX_ALARMCNT_ADDR, 0x00000000); + if (rc != 0) + return; + } +} + +#define MAX_TRY 3 +int trng4xx_random(u32 *rand_val) +{ + u32 val = 0; + int rc; + u16 try_cnt = 0; + + down(&trng4xx_dev.access_prot); + do { + rc = trng4xx_hw_read32(TRNG4XX_STATUS_ADDR, &val); + if (rc != 0) + goto err; + } while ((val & TRNG4XX_STATUS_BUSY) && ++try_cnt <= MAX_TRY); + if (val & TRNG4XX_STATUS_BUSY) { + rc = -EINPROGRESS; + goto err; + } + rc = trng4xx_hw_read32(TRNG4XX_OUTPUT_ADDR, rand_val); + +err: + up(&trng4xx_dev.access_prot); + return rc; +} +EXPORT_SYMBOL_GPL(trng4xx_random); + +static int trng4xx_data_present(struct hwrng *rng, int wait) +{ + struct trng4xx_dev *dev = (struct trng4xx_dev *) rng->priv; + int i; + u32 val; + + down(&trng4xx_dev.access_prot); + for (i = 0; i < 20; i++) { + udelay(10); + trng4xx_hw_read32(TRNG4XX_STATUS_ADDR, &val); + if (!(val & TRNG4XX_STATUS_BUSY)) { + trng4xx_hw_read32(TRNG4XX_OUTPUT_ADDR, &dev->datum); + break; + } + if (!wait) + break; + } + up(&trng4xx_dev.access_prot); + return (val & TRNG4XX_STATUS_BUSY) ? 0 : 1; +} + +static int trng4xx_data_read(struct hwrng *rng, u32 *data) +{ + struct trng4xx_dev *dev = (struct trng4xx_dev *) rng->priv; + + *data = dev->datum; + //printk("*data = 0x%08x\n", *data); + return 4; +} + +static int trng4xx_init(struct hwrng *rng) +{ + return trng4xx_hw_init(); +} + +static void trng4xx_cleanup(struct hwrng *rng) +{ + trng4xx_hw_deinit(); +} + +static struct hwrng trng4xx_func = { + .name = "ppc4xx-trng", + .init = trng4xx_init, + .cleanup = trng4xx_cleanup, + .data_present = trng4xx_data_present, + .data_read = trng4xx_data_read, + .priv = (unsigned long) &trng4xx_dev, +}; + +/** + * Setup Driver with platform registration + * + */ +static int __devinit trng4xx_probe(struct of_device *ofdev, + const struct of_device_id *match) +{ + struct hal_config hw_cfg; + int rc; + + hw_cfg.ofdev = ofdev; + rc = trng4xx_config_set(&hw_cfg); + if (rc != 0) + return rc; + + TRNG4XX_LOG("AMCC 4xx TRNG v%s @0x%02X_%08X size %d IRQ %d\n", + TRNG4XX_VER_STR, + (u32) (trng4xx_dev.res.start >> 32), + (u32) trng4xx_dev.res.start, + (u32) (trng4xx_dev.res.end - trng4xx_dev.res.start + 1), + trng4xx_dev.irq); + + init_MUTEX(&trng4xx_dev.access_prot); + + rc = hwrng_register(&trng4xx_func); + if (rc) { + printk(KERN_ERR + "AMCC 4xx TRNG registering failed error %d\n", rc); + goto err; + } + + return rc; + +err: + trng4xx_pka_config_clear(); + return rc; +} + +static int __devexit trng4xx_remove(struct of_device *dev) +{ + hwrng_unregister(&trng4xx_func); + trng4xx_pka_config_clear(); + return 0; +} + +static struct of_device_id trng4xx_match[] = { + { .compatible = "ppc4xx-trng", }, + { .compatible = "amcc,ppc4xx-trng", }, + { }, +}; + +static struct of_platform_driver trng4xx_driver = { + .name = "ppc4xx-trng", + .match_table = trng4xx_match, + .probe = trng4xx_probe, + .remove = trng4xx_remove, +}; + +static int __init mod_init(void) +{ + return of_register_platform_driver(&trng4xx_driver); +} + +static void __exit mod_exit(void) +{ + of_unregister_platform_driver(&trng4xx_driver); +} + +module_init(mod_init); +module_exit(mod_exit); + +MODULE_DESCRIPTION("AMCC 4xx True Random Number Generator"); +MODULE_LICENSE("GPL"); |