Add JZ4780 SoC and X1000 SoC random number generator driver,
based on PrasannaKumar Muralidharan's JZ4780 RNG driver.
Tested-by: 周正 (Zhou Zheng) <sernia.zhou@xxxxxxxxxxx>
Tested-by: Mathieu Malaterre <malat@xxxxxxxxxx>
Suggested-by: Jeffrey Walton <noloader@xxxxxxxxx>
Signed-off-by: PrasannaKumar Muralidharan <prasannatsmkumar@xxxxxxxxx>
Signed-off-by: 周琰杰 (Zhou Yanjie) <zhouyanjie@xxxxxxxxxxxxxx>
---
drivers/char/hw_random/Kconfig | 15 ++++
drivers/char/hw_random/Makefile | 1 +
drivers/char/hw_random/ingenic-rng.c | 154 +++++++++++++++++++++++++++++++++++
3 files changed, 170 insertions(+)
create mode 100644 drivers/char/hw_random/ingenic-rng.c
diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
index 0ad17efc96df..fcb06027cd88 100644
--- a/drivers/char/hw_random/Kconfig
+++ b/drivers/char/hw_random/Kconfig
@@ -257,6 +257,21 @@ config HW_RANDOM_IMX_RNGC
If unsure, say Y.
+config HW_RANDOM_INGENIC_RNG
+ tristate "Ingenic Random Number Generator support"
+ depends on HW_RANDOM
+ depends on MACH_JZ4780 || MACH_X1000
+ default HW_RANDOM
+ ---help---
+ This driver provides kernel-side support for the Random Number Generator
+ hardware found in ingenic JZ4780 and X1000 SoC. MIPS Creator CI20 uses
+ JZ4780 SoC, YSH & ATIL CU1000-Neo uses X1000 SoC.
+
+ To compile this driver as a module, choose M here: the
+ module will be called ingenic-rng.
+
+ 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 2c6724735345..acb1a1978d23 100644
--- a/drivers/char/hw_random/Makefile
+++ b/drivers/char/hw_random/Makefile
@@ -22,6 +22,7 @@ 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_IMX_RNGC) += imx-rngc.o
+obj-$(CONFIG_HW_RANDOM_INGENIC_RNG) += ingenic-rng.o
obj-$(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-rng.c b/drivers/char/hw_random/ingenic-rng.c
new file mode 100644
index 000000000000..d704cef64b64
--- /dev/null
+++ b/drivers/char/hw_random/ingenic-rng.c
@@ -0,0 +1,154 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Ingenic Random Number Generator driver
+ * Copyright (c) 2017 PrasannaKumar Muralidharan <prasannatsmkumar@xxxxxxxxx>
+ * Copyright (c) 2020 周琰杰 (Zhou Yanjie) <zhouyanjie@xxxxxxxxxxxxxx>
+ */
+
+#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>
+
+/* RNG register offsets */
+#define RNG_REG_ERNG_OFFSET 0x0
+#define RNG_REG_RNG_OFFSET 0x4
+
+/* bits within the ERND register */
+#define ERNG_READY BIT(31)
+#define ERNG_ENABLE BIT(0)
+
+enum ingenic_rng_version {
+ ID_JZ4780,
+ ID_X1000,
+};
+
+/* Device associated memory */
+struct ingenic_rng {
+ enum ingenic_rng_version version;
+
+ void __iomem *base;
+ struct hwrng rng;
+};
+
+static int ingenic_rng_init(struct hwrng *rng)
+{
+ struct ingenic_rng *priv = container_of(rng, struct ingenic_rng, rng);
+
+ writel(ERNG_ENABLE, priv->base + RNG_REG_ERNG_OFFSET);
+
+ return 0;
+}
+
+static void ingenic_rng_cleanup(struct hwrng *rng)
+{
+ struct ingenic_rng *priv = container_of(rng, struct ingenic_rng, rng);
+
+ writel(0, priv->base + RNG_REG_ERNG_OFFSET);
+}
+
+static int ingenic_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
+{
+ struct ingenic_rng *priv = container_of(rng, struct ingenic_rng, rng);
+ u32 *data = buf;
+ u32 status;
+ int ret;
+
+ if (priv->version >= ID_X1000) {
+ ret = readl_poll_timeout(priv->base + RNG_REG_ERNG_OFFSET, status,
+ status & ERNG_READY, 10, 1000);
+ if (ret == -ETIMEDOUT) {
+ pr_err("%s: Wait for RNG data ready timeout\n", __func__);
+ return ret;
+ }
+ } else {
+ /*
+ * A delay is required so that the current RNG data is not bit shifted
+ * version of previous RNG data which could happen if random data is
+ * read continuously from this device.
+ */
+ udelay(20);
+ }
+
+ *data = readl(priv->base + RNG_REG_RNG_OFFSET);
+
+ return 4;
+}
+
+static int ingenic_rng_probe(struct platform_device *pdev)
+{
+ struct ingenic_rng *priv;
+ int ret;
+
+ priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(priv->base)) {
+ pr_err("%s: Failed to map RNG registers\n", __func__);
+ ret = PTR_ERR(priv->base);
+ goto err_free_rng;
+ }
+
+ priv->version = (enum ingenic_rng_version)of_device_get_match_data(&pdev->dev);
+
+ priv->rng.name = pdev->name;
+ priv->rng.init = ingenic_rng_init;
+ priv->rng.cleanup = ingenic_rng_cleanup;
+ priv->rng.read = ingenic_rng_read;
+
+ ret = hwrng_register(&priv->rng);
+ if (ret) {
+ dev_err(&pdev->dev, "Failed to register hwrng\n");
+ goto err_free_rng;
+ }
+
+ platform_set_drvdata(pdev, priv);
+
+ dev_info(&pdev->dev, "Ingenic RNG driver registered\n");
+ return 0;
+
+err_free_rng:
+ kfree(priv);
+ return ret;
+}
+
+static int ingenic_rng_remove(struct platform_device *pdev)
+{
+ struct ingenic_rng *priv = platform_get_drvdata(pdev);
+
+ hwrng_unregister(&priv->rng);
+
+ writel(0, priv->base + RNG_REG_ERNG_OFFSET);
+
+ return 0;
+}
+
+static const struct of_device_id ingenic_rng_of_match[] = {
+ { .compatible = "ingenic,jz4780-rng", .data = (void *) ID_JZ4780 },
+ { .compatible = "ingenic,x1000-rng", .data = (void *) ID_X1000 },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, ingenic_rng_of_match);
+
+static struct platform_driver ingenic_rng_driver = {
+ .probe = ingenic_rng_probe,
+ .remove = ingenic_rng_remove,
+ .driver = {
+ .name = "ingenic-rng",
+ .of_match_table = ingenic_rng_of_match,
+ },
+};
+
+module_platform_driver(ingenic_rng_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("PrasannaKumar Muralidharan <prasannatsmkumar@xxxxxxxxx>");
+MODULE_AUTHOR("周琰杰 (Zhou Yanjie) <zhouyanjie@xxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Ingenic Random Number Generator driver");
--
2.11.0
