[PATCH v4 3/5] rng: Add StarFive JH7110 RNG driver
Chanho Park
chanho61.park at samsung.com
Wed Nov 1 13:16:50 CET 2023
Adds to support JH7110 TRNG driver which is based on linux kernel's
jh7110-trng.c. This can support to generate 256-bit random numbers and
128-bit but this makes 256-bit default for convenience.
Signed-off-by: Chanho Park <chanho61.park at samsung.com>
---
drivers/rng/Kconfig | 6 +
drivers/rng/Makefile | 1 +
drivers/rng/jh7110_rng.c | 274 +++++++++++++++++++++++++++++++++++++++
3 files changed, 281 insertions(+)
create mode 100644 drivers/rng/jh7110_rng.c
diff --git a/drivers/rng/Kconfig b/drivers/rng/Kconfig
index 994cc35b2744..0dba1e06b429 100644
--- a/drivers/rng/Kconfig
+++ b/drivers/rng/Kconfig
@@ -91,4 +91,10 @@ config TPM_RNG
functionality. Enable random number generator on TPM
devices.
+config RNG_JH7110
+ bool "StarFive JH7110 Random Number Generator support"
+ depends on DM_RNG && STARFIVE_JH7110
+ help
+ Enable True Random Number Generator in StarFive JH7110 SoCs.
+
endif
diff --git a/drivers/rng/Makefile b/drivers/rng/Makefile
index 47b323e61ee3..9de762c8a1c3 100644
--- a/drivers/rng/Makefile
+++ b/drivers/rng/Makefile
@@ -15,3 +15,4 @@ obj-$(CONFIG_RNG_IPROC200) += iproc_rng200.o
obj-$(CONFIG_RNG_SMCCC_TRNG) += smccc_trng.o
obj-$(CONFIG_RNG_ARM_RNDR) += arm_rndr.o
obj-$(CONFIG_TPM_RNG) += tpm_rng.o
+obj-$(CONFIG_RNG_JH7110) += jh7110_rng.o
diff --git a/drivers/rng/jh7110_rng.c b/drivers/rng/jh7110_rng.c
new file mode 100644
index 000000000000..eb21afe4e7cb
--- /dev/null
+++ b/drivers/rng/jh7110_rng.c
@@ -0,0 +1,274 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * TRNG driver for the StarFive JH7110 SoC
+ *
+ */
+
+#include <clk.h>
+#include <dm.h>
+#include <reset.h>
+#include <rng.h>
+#include <asm/io.h>
+#include <linux/iopoll.h>
+
+/* trng register offset */
+#define STARFIVE_CTRL 0x00
+#define STARFIVE_STAT 0x04
+#define STARFIVE_MODE 0x08
+#define STARFIVE_SMODE 0x0C
+#define STARFIVE_IE 0x10
+#define STARFIVE_ISTAT 0x14
+#define STARFIVE_RAND0 0x20
+#define STARFIVE_RAND1 0x24
+#define STARFIVE_RAND2 0x28
+#define STARFIVE_RAND3 0x2C
+#define STARFIVE_RAND4 0x30
+#define STARFIVE_RAND5 0x34
+#define STARFIVE_RAND6 0x38
+#define STARFIVE_RAND7 0x3C
+#define STARFIVE_AUTO_RQSTS 0x60
+#define STARFIVE_AUTO_AGE 0x64
+
+/* CTRL CMD */
+#define STARFIVE_CTRL_EXEC_NOP 0x0
+#define STARFIVE_CTRL_GENE_RANDNUM 0x1
+#define STARFIVE_CTRL_EXEC_RANDRESEED 0x2
+
+/* STAT */
+#define STARFIVE_STAT_NONCE_MODE BIT(2)
+#define STARFIVE_STAT_R256 BIT(3)
+#define STARFIVE_STAT_MISSION_MODE BIT(8)
+#define STARFIVE_STAT_SEEDED BIT(9)
+#define STARFIVE_STAT_LAST_RESEED(x) ((x) << 16)
+#define STARFIVE_STAT_SRVC_RQST BIT(27)
+#define STARFIVE_STAT_RAND_GENERATING BIT(30)
+#define STARFIVE_STAT_RAND_SEEDING BIT(31)
+#define STARFIVE_STAT_RUNNING (STARFIVE_STAT_RAND_GENERATING | \
+ STARFIVE_STAT_RAND_SEEDING)
+
+/* MODE */
+#define STARFIVE_MODE_R256 BIT(3)
+
+/* SMODE */
+#define STARFIVE_SMODE_NONCE_MODE BIT(2)
+#define STARFIVE_SMODE_MISSION_MODE BIT(8)
+#define STARFIVE_SMODE_MAX_REJECTS(x) ((x) << 16)
+
+/* IE */
+#define STARFIVE_IE_RAND_RDY_EN BIT(0)
+#define STARFIVE_IE_SEED_DONE_EN BIT(1)
+#define STARFIVE_IE_LFSR_LOCKUP_EN BIT(4)
+#define STARFIVE_IE_GLBL_EN BIT(31)
+
+#define STARFIVE_IE_ALL (STARFIVE_IE_GLBL_EN | \
+ STARFIVE_IE_RAND_RDY_EN | \
+ STARFIVE_IE_SEED_DONE_EN | \
+ STARFIVE_IE_LFSR_LOCKUP_EN)
+
+/* ISTAT */
+#define STARFIVE_ISTAT_RAND_RDY BIT(0)
+#define STARFIVE_ISTAT_SEED_DONE BIT(1)
+#define STARFIVE_ISTAT_LFSR_LOCKUP BIT(4)
+
+#define STARFIVE_RAND_LEN sizeof(u32)
+
+enum mode {
+ PRNG_128BIT,
+ PRNG_256BIT,
+};
+
+struct starfive_trng_plat {
+ void *base;
+ struct clk *hclk;
+ struct clk *ahb;
+ struct reset_ctl *rst;
+ u32 mode;
+};
+
+static inline int starfive_trng_wait_idle(struct starfive_trng_plat *trng)
+{
+ u32 stat;
+
+ return readl_relaxed_poll_timeout(trng->base + STARFIVE_STAT, stat,
+ !(stat & STARFIVE_STAT_RUNNING),
+ 100000);
+}
+
+static inline void starfive_trng_irq_mask_clear(struct starfive_trng_plat *trng)
+{
+ /* clear register: ISTAT */
+ u32 data = readl(trng->base + STARFIVE_ISTAT);
+
+ writel(data, trng->base + STARFIVE_ISTAT);
+}
+
+static int starfive_trng_cmd(struct starfive_trng_plat *trng, u32 cmd)
+{
+ u32 stat, flg;
+ int ret;
+
+ switch (cmd) {
+ case STARFIVE_CTRL_GENE_RANDNUM:
+ writel(cmd, trng->base + STARFIVE_CTRL);
+ flg = STARFIVE_ISTAT_RAND_RDY;
+ break;
+ case STARFIVE_CTRL_EXEC_RANDRESEED:
+ writel(cmd, trng->base + STARFIVE_CTRL);
+ flg = STARFIVE_ISTAT_SEED_DONE;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ ret = readl_relaxed_poll_timeout(trng->base + STARFIVE_ISTAT, stat,
+ (stat & flg), 1000);
+ writel(flg, trng->base + STARFIVE_ISTAT);
+
+ return ret;
+}
+
+static int starfive_trng_read(struct udevice *dev, void *data, size_t len)
+{
+ struct starfive_trng_plat *trng = dev_get_plat(dev);
+ u8 *buffer = data;
+ int iter_mask;
+
+ if (trng->mode == PRNG_256BIT)
+ iter_mask = 7;
+ else
+ iter_mask = 3;
+
+ for (int i = 0; len; ++i, i &= iter_mask) {
+ u32 val;
+ size_t step;
+ int ret;
+
+ if (!i) {
+ ret = starfive_trng_cmd(trng,
+ STARFIVE_CTRL_GENE_RANDNUM);
+ if (ret)
+ return ret;
+ }
+
+ val = readl(trng->base + STARFIVE_RAND0 +
+ (i * STARFIVE_RAND_LEN));
+ step = min_t(size_t, len, STARFIVE_RAND_LEN);
+ memcpy(buffer, &val, step);
+ buffer += step;
+ len -= step;
+ }
+
+ return 0;
+}
+
+static int starfive_trng_init(struct starfive_trng_plat *trng)
+{
+ u32 mode, intr = 0;
+
+ /* setup Auto Request/Age register */
+ writel(0, trng->base + STARFIVE_AUTO_AGE);
+ writel(0, trng->base + STARFIVE_AUTO_RQSTS);
+
+ /* clear register: ISTAT */
+ starfive_trng_irq_mask_clear(trng);
+
+ intr |= STARFIVE_IE_ALL;
+ writel(intr, trng->base + STARFIVE_IE);
+
+ mode = readl(trng->base + STARFIVE_MODE);
+
+ switch (trng->mode) {
+ case PRNG_128BIT:
+ mode &= ~STARFIVE_MODE_R256;
+ break;
+ case PRNG_256BIT:
+ mode |= STARFIVE_MODE_R256;
+ break;
+ default:
+ mode |= STARFIVE_MODE_R256;
+ break;
+ }
+
+ writel(mode, trng->base + STARFIVE_MODE);
+
+ return starfive_trng_cmd(trng, STARFIVE_CTRL_EXEC_RANDRESEED);
+}
+
+static int starfive_trng_probe(struct udevice *dev)
+{
+ struct starfive_trng_plat *pdata = dev_get_plat(dev);
+ int err;
+
+ err = clk_enable(pdata->hclk);
+ if (err)
+ return err;
+
+ err = clk_enable(pdata->ahb);
+ if (err)
+ goto err_ahb;
+
+ err = reset_deassert(pdata->rst);
+ if (err)
+ goto err_reset;
+
+ pdata->mode = PRNG_256BIT;
+
+ err = starfive_trng_init(pdata);
+ if (err)
+ goto err_trng_init;
+
+ return 0;
+
+err_trng_init:
+ reset_assert(pdata->rst);
+err_reset:
+ clk_disable(pdata->ahb);
+err_ahb:
+ clk_disable(pdata->hclk);
+
+ return err;
+}
+
+static int starfive_trng_of_to_plat(struct udevice *dev)
+{
+ struct starfive_trng_plat *pdata = dev_get_plat(dev);
+
+ pdata->base = (void *)dev_read_addr(dev);
+ if (!pdata->base)
+ return -ENODEV;
+
+ pdata->hclk = devm_clk_get(dev, "hclk");
+ if (IS_ERR(pdata->hclk))
+ return -ENODEV;
+
+ pdata->ahb = devm_clk_get(dev, "ahb");
+ if (IS_ERR(pdata->ahb))
+ return -ENODEV;
+
+ pdata->rst = devm_reset_control_get(dev, NULL);
+ if (IS_ERR(pdata->rst))
+ return -ENODEV;
+
+ return 0;
+}
+
+static const struct dm_rng_ops starfive_trng_ops = {
+ .read = starfive_trng_read,
+};
+
+static const struct udevice_id starfive_trng_match[] = {
+ {
+ .compatible = "starfive,jh7110-trng",
+ },
+ {},
+};
+
+U_BOOT_DRIVER(starfive_trng) = {
+ .name = "jh7110-trng",
+ .id = UCLASS_RNG,
+ .of_match = starfive_trng_match,
+ .probe = starfive_trng_probe,
+ .ops = &starfive_trng_ops,
+ .plat_auto = sizeof(struct starfive_trng_plat),
+ .of_to_plat = starfive_trng_of_to_plat,
+};
--
2.39.2
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