diff options
Diffstat (limited to 'drivers/rng')
| -rw-r--r-- | drivers/rng/Kconfig | 22 | ||||
| -rw-r--r-- | drivers/rng/Makefile | 8 | ||||
| -rw-r--r-- | drivers/rng/rng-uclass.c | 23 | ||||
| -rw-r--r-- | drivers/rng/sandbox_rng.c | 56 | ||||
| -rw-r--r-- | drivers/rng/stm32mp1_rng.c | 160 |
5 files changed, 269 insertions, 0 deletions
diff --git a/drivers/rng/Kconfig b/drivers/rng/Kconfig new file mode 100644 index 00000000000..35a3bd192aa --- /dev/null +++ b/drivers/rng/Kconfig @@ -0,0 +1,22 @@ +config DM_RNG + bool "Driver support for Random Number Generator devices" + depends on DM + help + Enable driver model for random number generator(rng) devices. + This interface is used to initialise the rng device and to + read the random seed from the device. + +config RNG_SANDBOX + bool "Sandbox random number generator" + depends on SANDBOX && DM_RNG + select CONFIG_LIB_RAND + help + Enable random number generator for sandbox. This is an + emulation of a rng device. + +config RNG_STM32MP1 + bool "Enable random number generator for STM32MP1" + depends on ARCH_STM32MP && DM_RNG + default n + help + Enable STM32MP1 rng driver. diff --git a/drivers/rng/Makefile b/drivers/rng/Makefile new file mode 100644 index 00000000000..35170055415 --- /dev/null +++ b/drivers/rng/Makefile @@ -0,0 +1,8 @@ +# SPDX-License-Identifier: GPL-2.0+ +# +# Copyright (c) 2019, Linaro Limited +# + +obj-$(CONFIG_DM_RNG) += rng-uclass.o +obj-$(CONFIG_RNG_SANDBOX) += sandbox_rng.o +obj-$(CONFIG_RNG_STM32MP1) += stm32mp1_rng.o diff --git a/drivers/rng/rng-uclass.c b/drivers/rng/rng-uclass.c new file mode 100644 index 00000000000..b6af3b8606a --- /dev/null +++ b/drivers/rng/rng-uclass.c @@ -0,0 +1,23 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (c) 2019, Linaro Limited + */ + +#include <common.h> +#include <dm.h> +#include <rng.h> + +int dm_rng_read(struct udevice *dev, void *buffer, size_t size) +{ + const struct dm_rng_ops *ops = device_get_ops(dev); + + if (!ops->read) + return -ENOSYS; + + return ops->read(dev, buffer, size); +} + +UCLASS_DRIVER(rng) = { + .name = "rng", + .id = UCLASS_RNG, +}; diff --git a/drivers/rng/sandbox_rng.c b/drivers/rng/sandbox_rng.c new file mode 100644 index 00000000000..cd0b0ac77b6 --- /dev/null +++ b/drivers/rng/sandbox_rng.c @@ -0,0 +1,56 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (c) 2019, Linaro Limited + */ + +#include <common.h> +#include <dm.h> +#include <rng.h> + +#include <linux/string.h> + +static int sandbox_rng_read(struct udevice *dev, void *data, size_t len) +{ + unsigned int i, seed, random; + unsigned char *buf = data; + size_t nrem, nloops; + + if (!len) + return 0; + + nloops = len / sizeof(random); + seed = get_timer(0) ^ rand(); + srand(seed); + + for (i = 0, nrem = len; i < nloops; i++) { + random = rand(); + memcpy(buf, &random, sizeof(random)); + buf += sizeof(random); + nrem -= sizeof(random); + } + + if (nrem) { + random = rand(); + memcpy(buf, &random, nrem); + } + + return 0; +} + +static const struct dm_rng_ops sandbox_rng_ops = { + .read = sandbox_rng_read, +}; + +static const struct udevice_id sandbox_rng_match[] = { + { + .compatible = "sandbox,sandbox-rng", + }, + {}, +}; + +U_BOOT_DRIVER(sandbox_rng) = { + .name = "sandbox-rng", + .id = UCLASS_RNG, + .of_match = sandbox_rng_match, + .ops = &sandbox_rng_ops, +}; diff --git a/drivers/rng/stm32mp1_rng.c b/drivers/rng/stm32mp1_rng.c new file mode 100644 index 00000000000..dab3b995eb6 --- /dev/null +++ b/drivers/rng/stm32mp1_rng.c @@ -0,0 +1,160 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (c) 2019, Linaro Limited + */ + +#include <common.h> +#include <clk.h> +#include <dm.h> +#include <reset.h> +#include <rng.h> + +#include <asm/io.h> +#include <linux/iopoll.h> +#include <linux/kernel.h> + +#define RNG_CR 0x00 +#define RNG_CR_RNGEN BIT(2) +#define RNG_CR_CED BIT(5) + +#define RNG_SR 0x04 +#define RNG_SR_SEIS BIT(6) +#define RNG_SR_CEIS BIT(5) +#define RNG_SR_SECS BIT(2) +#define RNG_SR_DRDY BIT(0) + +#define RNG_DR 0x08 + +struct stm32_rng_platdata { + fdt_addr_t base; + struct clk clk; + struct reset_ctl rst; +}; + +static int stm32_rng_read(struct udevice *dev, void *data, size_t len) +{ + int retval = 0, i; + u32 sr, count, reg; + size_t increment; + struct stm32_rng_platdata *pdata = dev_get_platdata(dev); + + while (len > 0) { + retval = readl_poll_timeout(pdata->base + RNG_SR, sr, + sr & RNG_SR_DRDY, 10000); + if (retval) + return retval; + + if (sr & (RNG_SR_SEIS | RNG_SR_SECS)) { + /* As per SoC TRM */ + clrbits_le32(pdata->base + RNG_SR, RNG_SR_SEIS); + for (i = 0; i < 12; i++) + readl(pdata->base + RNG_DR); + if (readl(pdata->base + RNG_SR) & RNG_SR_SEIS) { + printf("RNG Noise"); + return -EIO; + } + /* start again */ + continue; + } + + /* + * Once the DRDY bit is set, the RNG_DR register can + * be read four consecutive times. + */ + count = 4; + while (len && count) { + reg = readl(pdata->base + RNG_DR); + memcpy(data, ®, min(len, sizeof(u32))); + increment = min(len, sizeof(u32)); + data += increment; + len -= increment; + count--; + } + } + + return 0; +} + +static int stm32_rng_init(struct stm32_rng_platdata *pdata) +{ + int err; + + err = clk_enable(&pdata->clk); + if (err) + return err; + + /* Disable CED */ + writel(RNG_CR_RNGEN | RNG_CR_CED, pdata->base + RNG_CR); + + /* clear error indicators */ + writel(0, pdata->base + RNG_SR); + + return 0; +} + +static int stm32_rng_cleanup(struct stm32_rng_platdata *pdata) +{ + writel(0, pdata->base + RNG_CR); + + return clk_disable(&pdata->clk); +} + +static int stm32_rng_probe(struct udevice *dev) +{ + struct stm32_rng_platdata *pdata = dev_get_platdata(dev); + + reset_assert(&pdata->rst); + udelay(20); + reset_deassert(&pdata->rst); + + return stm32_rng_init(pdata); +} + +static int stm32_rng_remove(struct udevice *dev) +{ + struct stm32_rng_platdata *pdata = dev_get_platdata(dev); + + return stm32_rng_cleanup(pdata); +} + +static int stm32_rng_ofdata_to_platdata(struct udevice *dev) +{ + struct stm32_rng_platdata *pdata = dev_get_platdata(dev); + int err; + + pdata->base = dev_read_addr(dev); + if (!pdata->base) + return -ENOMEM; + + err = clk_get_by_index(dev, 0, &pdata->clk); + if (err) + return err; + + err = reset_get_by_index(dev, 0, &pdata->rst); + if (err) + return err; + + return 0; +} + +static const struct dm_rng_ops stm32_rng_ops = { + .read = stm32_rng_read, +}; + +static const struct udevice_id stm32_rng_match[] = { + { + .compatible = "st,stm32-rng", + }, + {}, +}; + +U_BOOT_DRIVER(stm32_rng) = { + .name = "stm32-rng", + .id = UCLASS_RNG, + .of_match = stm32_rng_match, + .ops = &stm32_rng_ops, + .probe = stm32_rng_probe, + .remove = stm32_rng_remove, + .platdata_auto_alloc_size = sizeof(struct stm32_rng_platdata), + .ofdata_to_platdata = stm32_rng_ofdata_to_platdata, +}; |