Add X1830 SoC digital true random number generator driver.
Tested-by: 周正 (Zhou Zheng) <sernia.zhou@xxxxxxxxxxx>
Co-developed-by: 漆鹏振 (Qi Pengzhen) <aric.pzqi@xxxxxxxxxxx>
Signed-off-by: 漆鹏振 (Qi Pengzhen) <aric.pzqi@xxxxxxxxxxx>
Signed-off-by: 周琰杰 (Zhou Yanjie) <zhouyanjie@xxxxxxxxxxxxxx>
---
drivers/char/hw_random/Kconfig | 14 +++
drivers/char/hw_random/Makefile | 1 +
drivers/char/hw_random/ingenic-trng.c | 161 ++++++++++++++++++++++++++++++++++
3 files changed, 176 insertions(+)
create mode 100644 drivers/char/hw_random/ingenic-trng.c
diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
index f976a49e1fb5..1232ca9a455c 100644
--- a/drivers/char/hw_random/Kconfig
+++ b/drivers/char/hw_random/Kconfig
@@ -282,6 +282,20 @@ config HW_RANDOM_INGENIC_RNG
If unsure, say Y.
+config HW_RANDOM_INGENIC_TRNG
+ tristate "Ingenic True Random Number Generator support"
+ depends on HW_RANDOM
+ depends on MACH_X1830
+ default HW_RANDOM
+ help
+ This driver provides kernel-side support for the True Random Number Generator
+ hardware found in ingenic X1830 SoC. YSH & ATIL CU1830-Neo uses X1830 SoC.
+
+ To compile this driver as a module, choose M here: the
+ module will be called ingenic-trng.
+
+ If unsure, say Y.
+
config HW_RANDOM_NOMADIK
tristate "ST-Ericsson Nomadik Random Number Generator support"
depends on ARCH_NOMADIK
diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile
index 26ae06844f09..8821d1c6f415 100644
--- a/drivers/char/hw_random/Makefile
+++ b/drivers/char/hw_random/Makefile
@@ -24,6 +24,7 @@ obj-$(CONFIG_HW_RANDOM_TX4939) += tx4939-rng.o
obj-$(CONFIG_HW_RANDOM_MXC_RNGA) += mxc-rnga.o
obj-$(CONFIG_HW_RANDOM_IMX_RNGC) += imx-rngc.o
obj-$(CONFIG_HW_RANDOM_INGENIC_RNG) += ingenic-rng.o
+obj-$(CONFIG_HW_RANDOM_INGENIC_TRNG) += ingenic-trng.o
obj-$(CONFIG_HW_RANDOM_OCTEON) += octeon-rng.o
obj-$(CONFIG_HW_RANDOM_NOMADIK) += nomadik-rng.o
obj-$(CONFIG_HW_RANDOM_PSERIES) += pseries-rng.o
diff --git a/drivers/char/hw_random/ingenic-trng.c b/drivers/char/hw_random/ingenic-trng.c
new file mode 100644
index 000000000000..954a8411d67d
--- /dev/null
+++ b/drivers/char/hw_random/ingenic-trng.c
@@ -0,0 +1,161 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Ingenic True Random Number Generator driver
+ * Copyright (c) 2019 漆鹏振 (Qi Pengzhen) <aric.pzqi@xxxxxxxxxxx>
+ * Copyright (c) 2020 周琰杰 (Zhou Yanjie) <zhouyanjie@xxxxxxxxxxxxxx>
+ */
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/hw_random.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+/* DTRNG register offsets */
+#define TRNG_REG_CFG_OFFSET 0x00
+#define TRNG_REG_RANDOMNUM_OFFSET 0x04
+#define TRNG_REG_STATUS_OFFSET 0x08
+
+/* bits within the CFG register */
+#define CFG_RDY_CLR BIT(12)
+#define CFG_INT_MASK BIT(11)
+#define CFG_GEN_EN BIT(0)
+
+/* bits within the STATUS register */
+#define STATUS_RANDOM_RDY BIT(0)
+
+struct ingenic_trng {
+ void __iomem *base;
+ struct clk *clk;
+ struct hwrng rng;
+};
+
+static int ingenic_trng_init(struct hwrng *rng)
+{
+ struct ingenic_trng *trng = container_of(rng, struct ingenic_trng, rng);
+ unsigned int ctrl;
+
+ ctrl = readl(trng->base + TRNG_REG_CFG_OFFSET);
+ ctrl |= CFG_GEN_EN;
+ writel(ctrl, trng->base + TRNG_REG_CFG_OFFSET);
+
+ return 0;
+}
+
+static void ingenic_trng_cleanup(struct hwrng *rng)
+{
+ struct ingenic_trng *trng = container_of(rng, struct ingenic_trng, rng);
+ unsigned int ctrl;
+
+ ctrl = readl(trng->base + TRNG_REG_CFG_OFFSET);
+ ctrl &= ~CFG_GEN_EN;
+ writel(ctrl, trng->base + TRNG_REG_CFG_OFFSET);
+}
+
+static int ingenic_trng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
+{
+ struct ingenic_trng *trng = container_of(rng, struct ingenic_trng, rng);
+ u32 *data = buf;
+ u32 status;
+ int ret;
+
+ ret = readl_poll_timeout(trng->base + TRNG_REG_STATUS_OFFSET, status,
+ status & STATUS_RANDOM_RDY, 10, 1000);
+ if (ret == -ETIMEDOUT) {
+ pr_err("%s: Wait for DTRNG data ready timeout\n", __func__);
+ return ret;
+ }
+
+ *data = readl(trng->base + TRNG_REG_RANDOMNUM_OFFSET);
+
+ return 4;
+}
+
+static int ingenic_trng_probe(struct platform_device *pdev)
+{
+ struct ingenic_trng *trng;
+ int ret;
+
+ trng = devm_kzalloc(&pdev->dev, sizeof(*trng), GFP_KERNEL);
+ if (!trng)
+ return -ENOMEM;
+
+ trng->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(trng->base)) {
+ pr_err("%s: Failed to map DTRNG registers\n", __func__);
+ ret = PTR_ERR(trng->base);
+ return PTR_ERR(trng->base);
+ }
+
+ trng->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(trng->clk)) {
+ ret = PTR_ERR(trng->clk);
+ pr_crit("%s: Cannot get DTRNG clock\n", __func__);
+ return PTR_ERR(trng->clk);
+ }
+
+ ret = clk_prepare_enable(trng->clk);
+ if (ret) {
+ pr_crit("%s: Unable to enable DTRNG clock\n", __func__);
+ return ret;
+ }
+
+ trng->rng.name = pdev->name;
+ trng->rng.init = ingenic_trng_init;
+ trng->rng.cleanup = ingenic_trng_cleanup;
+ trng->rng.read = ingenic_trng_read;
+
+ ret = hwrng_register(&trng->rng);
+ if (ret) {
+ dev_err(&pdev->dev, "Failed to register hwrng\n");
+ return ret;
+ }
+
+ platform_set_drvdata(pdev, trng);
+
+ dev_info(&pdev->dev, "Ingenic DTRNG driver registered\n");
+ return 0;
+}
+
+static int ingenic_trng_remove(struct platform_device *pdev)
+{
+ struct ingenic_trng *trng = platform_get_drvdata(pdev);
+ unsigned int ctrl;
+
+ hwrng_unregister(&trng->rng);
+
+ ctrl = readl(trng->base + TRNG_REG_CFG_OFFSET);
+ ctrl &= ~CFG_GEN_EN;
+ writel(ctrl, trng->base + TRNG_REG_CFG_OFFSET);
+
+ clk_disable_unprepare(trng->clk);
+
+ return 0;
+}
+
+static const struct of_device_id ingenic_trng_of_match[] = {
+ { .compatible = "ingenic,x1830-dtrng" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, ingenic_trng_of_match);
+
+static struct platform_driver ingenic_trng_driver = {
+ .probe = ingenic_trng_probe,
+ .remove = ingenic_trng_remove,
+ .driver = {
+ .name = "ingenic-trng",
+ .of_match_table = ingenic_trng_of_match,
+ },
+};
+
+module_platform_driver(ingenic_trng_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("漆鹏振 (Qi Pengzhen) <aric.pzqi@xxxxxxxxxxx>");
+MODULE_AUTHOR("周琰杰 (Zhou Yanjie) <zhouyanjie@xxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Ingenic True Random Number Generator driver");
--
2.11.0
