Adding upstream version 4.19.249.upstream/4.19.249upstream

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

1 files changed, 253 insertions, 0 deletions

diff --git a/drivers/nvmem/meson-mx-efuse.c b/drivers/nvmem/meson-mx-efuse.c
new file mode 100644
index 000000000..a085563e3
--- /dev/null
+++ b/drivers/nvmem/meson-mx-efuse.c
@@ -0,0 +1,253 @@
+/*
+ * Amlogic Meson6, Meson8 and Meson8b eFuse Driver
+ *
+ * Copyright (c) 2017 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * 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/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/delay.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/sizes.h>
+#include <linux/slab.h>
+
+#define MESON_MX_EFUSE_CNTL1					0x04
+#define MESON_MX_EFUSE_CNTL1_PD_ENABLE				BIT(27)
+#define MESON_MX_EFUSE_CNTL1_AUTO_RD_BUSY			BIT(26)
+#define MESON_MX_EFUSE_CNTL1_AUTO_RD_START			BIT(25)
+#define MESON_MX_EFUSE_CNTL1_AUTO_RD_ENABLE			BIT(24)
+#define MESON_MX_EFUSE_CNTL1_BYTE_WR_DATA			GENMASK(23, 16)
+#define MESON_MX_EFUSE_CNTL1_AUTO_WR_BUSY			BIT(14)
+#define MESON_MX_EFUSE_CNTL1_AUTO_WR_START			BIT(13)
+#define MESON_MX_EFUSE_CNTL1_AUTO_WR_ENABLE			BIT(12)
+#define MESON_MX_EFUSE_CNTL1_BYTE_ADDR_SET			BIT(11)
+#define MESON_MX_EFUSE_CNTL1_BYTE_ADDR_MASK			GENMASK(10, 0)
+
+#define MESON_MX_EFUSE_CNTL2					0x08
+
+#define MESON_MX_EFUSE_CNTL4					0x10
+#define MESON_MX_EFUSE_CNTL4_ENCRYPT_ENABLE			BIT(10)
+
+struct meson_mx_efuse_platform_data {
+	const char *name;
+	unsigned int word_size;
+};
+
+struct meson_mx_efuse {
+	void __iomem *base;
+	struct clk *core_clk;
+	struct nvmem_device *nvmem;
+	struct nvmem_config config;
+};
+
+static void meson_mx_efuse_mask_bits(struct meson_mx_efuse *efuse, u32 reg,
+				     u32 mask, u32 set)
+{
+	u32 data;
+
+	data = readl(efuse->base + reg);
+	data &= ~mask;
+	data |= (set & mask);
+
+	writel(data, efuse->base + reg);
+}
+
+static int meson_mx_efuse_hw_enable(struct meson_mx_efuse *efuse)
+{
+	int err;
+
+	err = clk_prepare_enable(efuse->core_clk);
+	if (err)
+		return err;
+
+	/* power up the efuse */
+	meson_mx_efuse_mask_bits(efuse, MESON_MX_EFUSE_CNTL1,
+				 MESON_MX_EFUSE_CNTL1_PD_ENABLE, 0);
+
+	meson_mx_efuse_mask_bits(efuse, MESON_MX_EFUSE_CNTL4,
+				 MESON_MX_EFUSE_CNTL4_ENCRYPT_ENABLE, 0);
+
+	return 0;
+}
+
+static void meson_mx_efuse_hw_disable(struct meson_mx_efuse *efuse)
+{
+	meson_mx_efuse_mask_bits(efuse, MESON_MX_EFUSE_CNTL1,
+				 MESON_MX_EFUSE_CNTL1_PD_ENABLE,
+				 MESON_MX_EFUSE_CNTL1_PD_ENABLE);
+
+	clk_disable_unprepare(efuse->core_clk);
+}
+
+static int meson_mx_efuse_read_addr(struct meson_mx_efuse *efuse,
+				    unsigned int addr, u32 *value)
+{
+	int err;
+	u32 regval;
+
+	/* write the address to read */
+	regval = FIELD_PREP(MESON_MX_EFUSE_CNTL1_BYTE_ADDR_MASK, addr);
+	meson_mx_efuse_mask_bits(efuse, MESON_MX_EFUSE_CNTL1,
+				 MESON_MX_EFUSE_CNTL1_BYTE_ADDR_MASK, regval);
+
+	/* inform the hardware that we changed the address */
+	meson_mx_efuse_mask_bits(efuse, MESON_MX_EFUSE_CNTL1,
+				 MESON_MX_EFUSE_CNTL1_BYTE_ADDR_SET,
+				 MESON_MX_EFUSE_CNTL1_BYTE_ADDR_SET);
+	meson_mx_efuse_mask_bits(efuse, MESON_MX_EFUSE_CNTL1,
+				 MESON_MX_EFUSE_CNTL1_BYTE_ADDR_SET, 0);
+
+	/* start the read process */
+	meson_mx_efuse_mask_bits(efuse, MESON_MX_EFUSE_CNTL1,
+				 MESON_MX_EFUSE_CNTL1_AUTO_RD_START,
+				 MESON_MX_EFUSE_CNTL1_AUTO_RD_START);
+	meson_mx_efuse_mask_bits(efuse, MESON_MX_EFUSE_CNTL1,
+				 MESON_MX_EFUSE_CNTL1_AUTO_RD_START, 0);
+
+	/*
+	 * perform a dummy read to ensure that the HW has the RD_BUSY bit set
+	 * when polling for the status below.
+	 */
+	readl(efuse->base + MESON_MX_EFUSE_CNTL1);
+
+	err = readl_poll_timeout_atomic(efuse->base + MESON_MX_EFUSE_CNTL1,
+			regval,
+			(!(regval & MESON_MX_EFUSE_CNTL1_AUTO_RD_BUSY)),
+			1, 1000);
+	if (err) {
+		dev_err(efuse->config.dev,
+			"Timeout while reading efuse address %u\n", addr);
+		return err;
+	}
+
+	*value = readl(efuse->base + MESON_MX_EFUSE_CNTL2);
+
+	return 0;
+}
+
+static int meson_mx_efuse_read(void *context, unsigned int offset,
+			       void *buf, size_t bytes)
+{
+	struct meson_mx_efuse *efuse = context;
+	u32 tmp;
+	int err, i, addr;
+
+	err = meson_mx_efuse_hw_enable(efuse);
+	if (err)
+		return err;
+
+	meson_mx_efuse_mask_bits(efuse, MESON_MX_EFUSE_CNTL1,
+				 MESON_MX_EFUSE_CNTL1_AUTO_RD_ENABLE,
+				 MESON_MX_EFUSE_CNTL1_AUTO_RD_ENABLE);
+
+	for (i = 0; i < bytes; i += efuse->config.word_size) {
+		addr = (offset + i) / efuse->config.word_size;
+
+		err = meson_mx_efuse_read_addr(efuse, addr, &tmp);
+		if (err)
+			break;
+
+		memcpy(buf + i, &tmp, efuse->config.word_size);
+	}
+
+	meson_mx_efuse_mask_bits(efuse, MESON_MX_EFUSE_CNTL1,
+				 MESON_MX_EFUSE_CNTL1_AUTO_RD_ENABLE, 0);
+
+	meson_mx_efuse_hw_disable(efuse);
+
+	return err;
+}
+
+static const struct meson_mx_efuse_platform_data meson6_efuse_data = {
+	.name = "meson6-efuse",
+	.word_size = 1,
+};
+
+static const struct meson_mx_efuse_platform_data meson8_efuse_data = {
+	.name = "meson8-efuse",
+	.word_size = 4,
+};
+
+static const struct meson_mx_efuse_platform_data meson8b_efuse_data = {
+	.name = "meson8b-efuse",
+	.word_size = 4,
+};
+
+static const struct of_device_id meson_mx_efuse_match[] = {
+	{ .compatible = "amlogic,meson6-efuse", .data = &meson6_efuse_data },
+	{ .compatible = "amlogic,meson8-efuse", .data = &meson8_efuse_data },
+	{ .compatible = "amlogic,meson8b-efuse", .data = &meson8b_efuse_data },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, meson_mx_efuse_match);
+
+static int meson_mx_efuse_probe(struct platform_device *pdev)
+{
+	const struct meson_mx_efuse_platform_data *drvdata;
+	struct meson_mx_efuse *efuse;
+	struct resource *res;
+
+	drvdata = of_device_get_match_data(&pdev->dev);
+	if (!drvdata)
+		return -EINVAL;
+
+	efuse = devm_kzalloc(&pdev->dev, sizeof(*efuse), GFP_KERNEL);
+	if (!efuse)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	efuse->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(efuse->base))
+		return PTR_ERR(efuse->base);
+
+	efuse->config.name = devm_kstrdup(&pdev->dev, drvdata->name,
+					  GFP_KERNEL);
+	efuse->config.owner = THIS_MODULE;
+	efuse->config.dev = &pdev->dev;
+	efuse->config.priv = efuse;
+	efuse->config.stride = drvdata->word_size;
+	efuse->config.word_size = drvdata->word_size;
+	efuse->config.size = SZ_512;
+	efuse->config.read_only = true;
+	efuse->config.reg_read = meson_mx_efuse_read;
+
+	efuse->core_clk = devm_clk_get(&pdev->dev, "core");
+	if (IS_ERR(efuse->core_clk)) {
+		dev_err(&pdev->dev, "Failed to get core clock\n");
+		return PTR_ERR(efuse->core_clk);
+	}
+
+	efuse->nvmem = devm_nvmem_register(&pdev->dev, &efuse->config);
+
+	return PTR_ERR_OR_ZERO(efuse->nvmem);
+}
+
+static struct platform_driver meson_mx_efuse_driver = {
+	.probe = meson_mx_efuse_probe,
+	.driver = {
+		.name = "meson-mx-efuse",
+		.of_match_table = meson_mx_efuse_match,
+	},
+};
+
+module_platform_driver(meson_mx_efuse_driver);
+
+MODULE_AUTHOR("Martin Blumenstingl <martin.blumenstingl@googlemail.com>");
+MODULE_DESCRIPTION("Amlogic Meson MX eFuse NVMEM driver");
+MODULE_LICENSE("GPL v2");