rockchip: rng: Add a driver for random number generator(rng) device
authorLin Jinhan <troy.lin@rock-chips.com>
Tue, 31 Mar 2020 09:39:59 +0000 (17:39 +0800)
committerKever Yang <kever.yang@rock-chips.com>
Wed, 29 Apr 2020 02:30:55 +0000 (10:30 +0800)
Add a driver for the rng device found on rockchip platforms.
Support rng module of crypto v1 and crypto v2.

Signed-off-by: Lin Jinhan <troy.lin@rock-chips.com>
Tested-by: Peter Robinson <pbrobinson@gmail.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
drivers/rng/Kconfig
drivers/rng/Makefile
drivers/rng/rockchip_rng.c [new file with mode: 0644]

index edb6152bb9d43ee8ef95d379a76d0a9b1af595de..e4b22d79ebcfb1f692213358f8094050ec1934e8 100644 (file)
@@ -31,4 +31,12 @@ config RNG_STM32MP1
        help
          Enable STM32MP1 rng driver.
 
+config RNG_ROCKCHIP
+       bool "Enable random number generator for rockchip crypto rng"
+       depends on ARCH_ROCKCHIP && DM_RNG
+       default n
+       help
+         Enable random number generator for rockchip.This driver is
+         support rng module of crypto v1 and crypto v2.
+
 endif
index 6a8a66779b5b30e4a077612d10e7eb6578d30a0a..44a00039173531d0cb7dad05c65561cf7b1303a3 100644 (file)
@@ -7,3 +7,4 @@ obj-$(CONFIG_DM_RNG) += rng-uclass.o
 obj-$(CONFIG_RNG_MESON) += meson-rng.o
 obj-$(CONFIG_RNG_SANDBOX) += sandbox_rng.o
 obj-$(CONFIG_RNG_STM32MP1) += stm32mp1_rng.o
+obj-$(CONFIG_RNG_ROCKCHIP) += rockchip_rng.o
diff --git a/drivers/rng/rockchip_rng.c b/drivers/rng/rockchip_rng.c
new file mode 100644 (file)
index 0000000..47fb140
--- /dev/null
@@ -0,0 +1,224 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2020 Fuzhou Rockchip Electronics Co., Ltd
+ */
+#include <asm/arch-rockchip/hardware.h>
+#include <asm/io.h>
+#include <common.h>
+#include <dm.h>
+#include <linux/iopoll.h>
+#include <linux/string.h>
+#include <rng.h>
+
+#define RK_HW_RNG_MAX 32
+
+#define _SBF(s, v)     ((v) << (s))
+
+/* start of CRYPTO V1 register define */
+#define CRYPTO_V1_CTRL                         0x0008
+#define CRYPTO_V1_RNG_START                    BIT(8)
+#define CRYPTO_V1_RNG_FLUSH                    BIT(9)
+
+#define CRYPTO_V1_TRNG_CTRL                    0x0200
+#define CRYPTO_V1_OSC_ENABLE                   BIT(16)
+#define CRYPTO_V1_TRNG_SAMPLE_PERIOD(x)                (x)
+
+#define CRYPTO_V1_TRNG_DOUT_0                  0x0204
+/* end of CRYPTO V1 register define */
+
+/* start of CRYPTO V2 register define */
+#define CRYPTO_V2_RNG_CTL                      0x0400
+#define CRYPTO_V2_RNG_64_BIT_LEN               _SBF(4, 0x00)
+#define CRYPTO_V2_RNG_128_BIT_LEN              _SBF(4, 0x01)
+#define CRYPTO_V2_RNG_192_BIT_LEN              _SBF(4, 0x02)
+#define CRYPTO_V2_RNG_256_BIT_LEN              _SBF(4, 0x03)
+#define CRYPTO_V2_RNG_FATESY_SOC_RING          _SBF(2, 0x00)
+#define CRYPTO_V2_RNG_SLOWER_SOC_RING_0                _SBF(2, 0x01)
+#define CRYPTO_V2_RNG_SLOWER_SOC_RING_1                _SBF(2, 0x02)
+#define CRYPTO_V2_RNG_SLOWEST_SOC_RING         _SBF(2, 0x03)
+#define CRYPTO_V2_RNG_ENABLE                   BIT(1)
+#define CRYPTO_V2_RNG_START                    BIT(0)
+#define CRYPTO_V2_RNG_SAMPLE_CNT               0x0404
+#define CRYPTO_V2_RNG_DOUT_0                   0x0410
+/* end of CRYPTO V2 register define */
+
+#define RK_RNG_TIME_OUT        50000  /* max 50ms */
+
+struct rk_rng_soc_data {
+       int (*rk_rng_read)(struct udevice *dev, void *data, size_t len);
+};
+
+struct rk_rng_platdata {
+       fdt_addr_t base;
+       struct rk_rng_soc_data *soc_data;
+};
+
+static int rk_rng_read_regs(fdt_addr_t addr, void *buf, size_t size)
+{
+       u32 count = RK_HW_RNG_MAX / sizeof(u32);
+       u32 reg, tmp_len;
+
+       if (size > RK_HW_RNG_MAX)
+               return -EINVAL;
+
+       while (size && count) {
+               reg = readl(addr);
+               tmp_len = min(size, sizeof(u32));
+               memcpy(buf, &reg, tmp_len);
+               addr += sizeof(u32);
+               buf += tmp_len;
+               size -= tmp_len;
+               count--;
+       }
+
+       return 0;
+}
+
+static int rk_v1_rng_read(struct udevice *dev, void *data, size_t len)
+{
+       struct rk_rng_platdata *pdata = dev_get_priv(dev);
+       u32 reg = 0;
+       int retval;
+
+       if (len > RK_HW_RNG_MAX)
+               return -EINVAL;
+
+       /* enable osc_ring to get entropy, sample period is set as 100 */
+       writel(CRYPTO_V1_OSC_ENABLE | CRYPTO_V1_TRNG_SAMPLE_PERIOD(100),
+              pdata->base + CRYPTO_V1_TRNG_CTRL);
+
+       rk_clrsetreg(pdata->base + CRYPTO_V1_CTRL, CRYPTO_V1_RNG_START,
+                    CRYPTO_V1_RNG_START);
+
+       retval = readl_poll_timeout(pdata->base + CRYPTO_V1_CTRL, reg,
+                                   !(reg & CRYPTO_V1_RNG_START),
+                                   RK_RNG_TIME_OUT);
+       if (retval)
+               goto exit;
+
+       rk_rng_read_regs(pdata->base + CRYPTO_V1_TRNG_DOUT_0, data, len);
+
+exit:
+       /* close TRNG */
+       rk_clrreg(pdata->base + CRYPTO_V1_CTRL, CRYPTO_V1_RNG_START);
+
+       return 0;
+}
+
+static int rk_v2_rng_read(struct udevice *dev, void *data, size_t len)
+{
+       struct rk_rng_platdata *pdata = dev_get_priv(dev);
+       u32 reg = 0;
+       int retval;
+
+       if (len > RK_HW_RNG_MAX)
+               return -EINVAL;
+
+       /* enable osc_ring to get entropy, sample period is set as 100 */
+       writel(100, pdata->base + CRYPTO_V2_RNG_SAMPLE_CNT);
+
+       reg |= CRYPTO_V2_RNG_256_BIT_LEN;
+       reg |= CRYPTO_V2_RNG_SLOWER_SOC_RING_0;
+       reg |= CRYPTO_V2_RNG_ENABLE;
+       reg |= CRYPTO_V2_RNG_START;
+
+       rk_clrsetreg(pdata->base + CRYPTO_V2_RNG_CTL, 0xffff, reg);
+
+       retval = readl_poll_timeout(pdata->base + CRYPTO_V2_RNG_CTL, reg,
+                                   !(reg & CRYPTO_V2_RNG_START),
+                                   RK_RNG_TIME_OUT);
+       if (retval)
+               goto exit;
+
+       rk_rng_read_regs(pdata->base + CRYPTO_V2_RNG_DOUT_0, data, len);
+
+exit:
+       /* close TRNG */
+       rk_clrreg(pdata->base + CRYPTO_V2_RNG_CTL, 0xffff);
+
+       return retval;
+}
+
+static int rockchip_rng_read(struct udevice *dev, void *data, size_t len)
+{
+       unsigned char *buf = data;
+       unsigned int i;
+       int ret = -EIO;
+
+       struct rk_rng_platdata *pdata = dev_get_priv(dev);
+
+       if (!len)
+               return 0;
+
+       if (!pdata->soc_data || !pdata->soc_data->rk_rng_read)
+               return -EINVAL;
+
+       for (i = 0; i < len / RK_HW_RNG_MAX; i++, buf += RK_HW_RNG_MAX) {
+               ret = pdata->soc_data->rk_rng_read(dev, buf, RK_HW_RNG_MAX);
+               if (ret)
+                       goto exit;
+       }
+
+       if (len % RK_HW_RNG_MAX)
+               ret = pdata->soc_data->rk_rng_read(dev, buf,
+                                                  len % RK_HW_RNG_MAX);
+
+exit:
+       return ret;
+}
+
+static int rockchip_rng_ofdata_to_platdata(struct udevice *dev)
+{
+       struct rk_rng_platdata *pdata = dev_get_priv(dev);
+
+       memset(pdata, 0x00, sizeof(*pdata));
+
+       pdata->base = (fdt_addr_t)dev_read_addr_ptr(dev);
+       if (!pdata->base)
+               return -ENOMEM;
+
+       return 0;
+}
+
+static int rockchip_rng_probe(struct udevice *dev)
+{
+       struct rk_rng_platdata *pdata = dev_get_priv(dev);
+
+       pdata->soc_data = (struct rk_rng_soc_data *)dev_get_driver_data(dev);
+
+       return 0;
+}
+
+static const struct rk_rng_soc_data rk_rng_v1_soc_data = {
+       .rk_rng_read = rk_v1_rng_read,
+};
+
+static const struct rk_rng_soc_data rk_rng_v2_soc_data = {
+       .rk_rng_read = rk_v2_rng_read,
+};
+
+static const struct dm_rng_ops rockchip_rng_ops = {
+       .read = rockchip_rng_read,
+};
+
+static const struct udevice_id rockchip_rng_match[] = {
+       {
+               .compatible = "rockchip,cryptov1-rng",
+               .data = (ulong)&rk_rng_v1_soc_data,
+       },
+       {
+               .compatible = "rockchip,cryptov2-rng",
+               .data = (ulong)&rk_rng_v2_soc_data,
+       },
+       {},
+};
+
+U_BOOT_DRIVER(rockchip_rng) = {
+       .name = "rockchip-rng",
+       .id = UCLASS_RNG,
+       .of_match = rockchip_rng_match,
+       .ops = &rockchip_rng_ops,
+       .probe = rockchip_rng_probe,
+       .ofdata_to_platdata = rockchip_rng_ofdata_to_platdata,
+       .priv_auto_alloc_size = sizeof(struct rk_rng_platdata),
+};