Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 258 insertions, 0 deletions

diff --git a/drivers/nvmem/sunxi_sid.c b/drivers/nvmem/sunxi_sid.c
new file mode 100644
index 000000000..69f8e972e
--- /dev/null
+++ b/drivers/nvmem/sunxi_sid.c
@@ -0,0 +1,258 @@
+/*
+ * Allwinner sunXi SoCs Security ID support.
+ *
+ * Copyright (c) 2013 Oliver Schinagl <oliver@schinagl.nl>
+ * Copyright (C) 2014 Maxime Ripard <maxime.ripard@free-electrons.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/nvmem-provider.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/random.h>
+
+/* Registers and special values for doing register-based SID readout on H3 */
+#define SUN8I_SID_PRCTL		0x40
+#define SUN8I_SID_RDKEY		0x60
+
+#define SUN8I_SID_OFFSET_MASK	0x1FF
+#define SUN8I_SID_OFFSET_SHIFT	16
+#define SUN8I_SID_OP_LOCK	(0xAC << 8)
+#define SUN8I_SID_READ		BIT(1)
+
+static struct nvmem_config econfig = {
+	.name = "sunxi-sid",
+	.read_only = true,
+	.stride = 4,
+	.word_size = 1,
+};
+
+struct sunxi_sid_cfg {
+	u32	value_offset;
+	u32	size;
+	bool	need_register_readout;
+};
+
+struct sunxi_sid {
+	void __iomem		*base;
+	u32			value_offset;
+};
+
+/* We read the entire key, due to a 32 bit read alignment requirement. Since we
+ * want to return the requested byte, this results in somewhat slower code and
+ * uses 4 times more reads as needed but keeps code simpler. Since the SID is
+ * only very rarely probed, this is not really an issue.
+ */
+static u8 sunxi_sid_read_byte(const struct sunxi_sid *sid,
+			      const unsigned int offset)
+{
+	u32 sid_key;
+
+	sid_key = ioread32be(sid->base + round_down(offset, 4));
+	sid_key >>= (offset % 4) * 8;
+
+	return sid_key; /* Only return the last byte */
+}
+
+static int sunxi_sid_read(void *context, unsigned int offset,
+			  void *val, size_t bytes)
+{
+	struct sunxi_sid *sid = context;
+	u8 *buf = val;
+
+	/* Offset the read operation to the real position of SID */
+	offset += sid->value_offset;
+
+	while (bytes--)
+		*buf++ = sunxi_sid_read_byte(sid, offset++);
+
+	return 0;
+}
+
+static int sun8i_sid_register_readout(const struct sunxi_sid *sid,
+				      const unsigned int offset,
+				      u32 *out)
+{
+	u32 reg_val;
+	int ret;
+
+	/* Set word, lock access, and set read command */
+	reg_val = (offset & SUN8I_SID_OFFSET_MASK)
+		  << SUN8I_SID_OFFSET_SHIFT;
+	reg_val |= SUN8I_SID_OP_LOCK | SUN8I_SID_READ;
+	writel(reg_val, sid->base + SUN8I_SID_PRCTL);
+
+	ret = readl_poll_timeout(sid->base + SUN8I_SID_PRCTL, reg_val,
+				 !(reg_val & SUN8I_SID_READ), 100, 250000);
+	if (ret)
+		return ret;
+
+	if (out)
+		*out = readl(sid->base + SUN8I_SID_RDKEY);
+
+	writel(0, sid->base + SUN8I_SID_PRCTL);
+
+	return 0;
+}
+
+/*
+ * On Allwinner H3, the value on the 0x200 offset of the SID controller seems
+ * to be not reliable at all.
+ * Read by the registers instead.
+ */
+static int sun8i_sid_read_byte_by_reg(const struct sunxi_sid *sid,
+				      const unsigned int offset,
+				      u8 *out)
+{
+	u32 word;
+	int ret;
+
+	ret = sun8i_sid_register_readout(sid, offset & ~0x03, &word);
+
+	if (ret)
+		return ret;
+
+	*out = (word >> ((offset & 0x3) * 8)) & 0xff;
+
+	return 0;
+}
+
+static int sun8i_sid_read_by_reg(void *context, unsigned int offset,
+				 void *val, size_t bytes)
+{
+	struct sunxi_sid *sid = context;
+	u8 *buf = val;
+	int ret;
+
+	while (bytes--) {
+		ret = sun8i_sid_read_byte_by_reg(sid, offset++, buf++);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int sunxi_sid_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct resource *res;
+	struct nvmem_device *nvmem;
+	struct sunxi_sid *sid;
+	int ret, i, size;
+	char *randomness;
+	const struct sunxi_sid_cfg *cfg;
+
+	sid = devm_kzalloc(dev, sizeof(*sid), GFP_KERNEL);
+	if (!sid)
+		return -ENOMEM;
+
+	cfg = of_device_get_match_data(dev);
+	if (!cfg)
+		return -EINVAL;
+	sid->value_offset = cfg->value_offset;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	sid->base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(sid->base))
+		return PTR_ERR(sid->base);
+
+	size = cfg->size;
+
+	econfig.size = size;
+	econfig.dev = dev;
+	if (cfg->need_register_readout)
+		econfig.reg_read = sun8i_sid_read_by_reg;
+	else
+		econfig.reg_read = sunxi_sid_read;
+	econfig.priv = sid;
+	nvmem = nvmem_register(&econfig);
+	if (IS_ERR(nvmem))
+		return PTR_ERR(nvmem);
+
+	randomness = kzalloc(size, GFP_KERNEL);
+	if (!randomness) {
+		ret = -EINVAL;
+		goto err_unreg_nvmem;
+	}
+
+	for (i = 0; i < size; i++)
+		econfig.reg_read(sid, i, &randomness[i], 1);
+
+	add_device_randomness(randomness, size);
+	kfree(randomness);
+
+	platform_set_drvdata(pdev, nvmem);
+
+	return 0;
+
+err_unreg_nvmem:
+	nvmem_unregister(nvmem);
+	return ret;
+}
+
+static int sunxi_sid_remove(struct platform_device *pdev)
+{
+	struct nvmem_device *nvmem = platform_get_drvdata(pdev);
+
+	return nvmem_unregister(nvmem);
+}
+
+static const struct sunxi_sid_cfg sun4i_a10_cfg = {
+	.size = 0x10,
+};
+
+static const struct sunxi_sid_cfg sun7i_a20_cfg = {
+	.size = 0x200,
+};
+
+static const struct sunxi_sid_cfg sun8i_h3_cfg = {
+	.value_offset = 0x200,
+	.size = 0x100,
+	.need_register_readout = true,
+};
+
+static const struct sunxi_sid_cfg sun50i_a64_cfg = {
+	.value_offset = 0x200,
+	.size = 0x100,
+};
+
+static const struct of_device_id sunxi_sid_of_match[] = {
+	{ .compatible = "allwinner,sun4i-a10-sid", .data = &sun4i_a10_cfg },
+	{ .compatible = "allwinner,sun7i-a20-sid", .data = &sun7i_a20_cfg },
+	{ .compatible = "allwinner,sun8i-a83t-sid", .data = &sun50i_a64_cfg },
+	{ .compatible = "allwinner,sun8i-h3-sid", .data = &sun8i_h3_cfg },
+	{ .compatible = "allwinner,sun50i-a64-sid", .data = &sun50i_a64_cfg },
+	{ .compatible = "allwinner,sun50i-h5-sid", .data = &sun50i_a64_cfg },
+	{/* sentinel */},
+};
+MODULE_DEVICE_TABLE(of, sunxi_sid_of_match);
+
+static struct platform_driver sunxi_sid_driver = {
+	.probe = sunxi_sid_probe,
+	.remove = sunxi_sid_remove,
+	.driver = {
+		.name = "eeprom-sunxi-sid",
+		.of_match_table = sunxi_sid_of_match,
+	},
+};
+module_platform_driver(sunxi_sid_driver);
+
+MODULE_AUTHOR("Oliver Schinagl <oliver@schinagl.nl>");
+MODULE_DESCRIPTION("Allwinner sunxi security id driver");
+MODULE_LICENSE("GPL");