Adding upstream version 6.6.15.upstream/6.6.15

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

1 files changed, 197 insertions, 0 deletions

diff --git a/drivers/nvmem/mxs-ocotp.c b/drivers/nvmem/mxs-ocotp.c
new file mode 100644
index 000000000..588ab56d7
--- /dev/null
+++ b/drivers/nvmem/mxs-ocotp.c
@@ -0,0 +1,197 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Freescale MXS On-Chip OTP driver
+ *
+ * Copyright (C) 2015 Stefan Wahren <stefan.wahren@i2se.com>
+ *
+ * Based on the driver from Huang Shijie and Christoph G. Baumann
+ */
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/nvmem-provider.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/stmp_device.h>
+
+/* OCOTP registers and bits */
+
+#define BM_OCOTP_CTRL_RD_BANK_OPEN	BIT(12)
+#define BM_OCOTP_CTRL_ERROR		BIT(9)
+#define BM_OCOTP_CTRL_BUSY		BIT(8)
+
+#define OCOTP_TIMEOUT		10000
+#define OCOTP_DATA_OFFSET	0x20
+
+struct mxs_ocotp {
+	struct clk *clk;
+	void __iomem *base;
+	struct nvmem_device *nvmem;
+};
+
+static int mxs_ocotp_wait(struct mxs_ocotp *otp)
+{
+	int timeout = OCOTP_TIMEOUT;
+	unsigned int status = 0;
+
+	while (timeout--) {
+		status = readl(otp->base);
+
+		if (!(status & (BM_OCOTP_CTRL_BUSY | BM_OCOTP_CTRL_ERROR)))
+			break;
+
+		cpu_relax();
+	}
+
+	if (status & BM_OCOTP_CTRL_BUSY)
+		return -EBUSY;
+	else if (status & BM_OCOTP_CTRL_ERROR)
+		return -EIO;
+
+	return 0;
+}
+
+static int mxs_ocotp_read(void *context, unsigned int offset,
+			  void *val, size_t bytes)
+{
+	struct mxs_ocotp *otp = context;
+	u32 *buf = val;
+	int ret;
+
+	ret = clk_enable(otp->clk);
+	if (ret)
+		return ret;
+
+	writel(BM_OCOTP_CTRL_ERROR, otp->base + STMP_OFFSET_REG_CLR);
+
+	ret = mxs_ocotp_wait(otp);
+	if (ret)
+		goto disable_clk;
+
+	/* open OCOTP banks for read */
+	writel(BM_OCOTP_CTRL_RD_BANK_OPEN, otp->base + STMP_OFFSET_REG_SET);
+
+	/* approximately wait 33 hclk cycles */
+	udelay(1);
+
+	ret = mxs_ocotp_wait(otp);
+	if (ret)
+		goto close_banks;
+
+	while (bytes) {
+		if ((offset < OCOTP_DATA_OFFSET) || (offset % 16)) {
+			/* fill up non-data register */
+			*buf++ = 0;
+		} else {
+			*buf++ = readl(otp->base + offset);
+		}
+
+		bytes -= 4;
+		offset += 4;
+	}
+
+close_banks:
+	/* close banks for power saving */
+	writel(BM_OCOTP_CTRL_RD_BANK_OPEN, otp->base + STMP_OFFSET_REG_CLR);
+
+disable_clk:
+	clk_disable(otp->clk);
+
+	return ret;
+}
+
+static struct nvmem_config ocotp_config = {
+	.name = "mxs-ocotp",
+	.stride = 16,
+	.word_size = 4,
+	.reg_read = mxs_ocotp_read,
+};
+
+struct mxs_data {
+	int size;
+};
+
+static const struct mxs_data imx23_data = {
+	.size = 0x220,
+};
+
+static const struct mxs_data imx28_data = {
+	.size = 0x2a0,
+};
+
+static const struct of_device_id mxs_ocotp_match[] = {
+	{ .compatible = "fsl,imx23-ocotp", .data = &imx23_data },
+	{ .compatible = "fsl,imx28-ocotp", .data = &imx28_data },
+	{ /* sentinel */},
+};
+MODULE_DEVICE_TABLE(of, mxs_ocotp_match);
+
+static void mxs_ocotp_action(void *data)
+{
+	clk_unprepare(data);
+}
+
+static int mxs_ocotp_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	const struct mxs_data *data;
+	struct mxs_ocotp *otp;
+	const struct of_device_id *match;
+	int ret;
+
+	match = of_match_device(dev->driver->of_match_table, dev);
+	if (!match || !match->data)
+		return -EINVAL;
+
+	otp = devm_kzalloc(dev, sizeof(*otp), GFP_KERNEL);
+	if (!otp)
+		return -ENOMEM;
+
+	otp->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(otp->base))
+		return PTR_ERR(otp->base);
+
+	otp->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(otp->clk))
+		return PTR_ERR(otp->clk);
+
+	ret = clk_prepare(otp->clk);
+	if (ret < 0) {
+		dev_err(dev, "failed to prepare clk: %d\n", ret);
+		return ret;
+	}
+
+	ret = devm_add_action_or_reset(&pdev->dev, mxs_ocotp_action, otp->clk);
+	if (ret)
+		return ret;
+
+	data = match->data;
+
+	ocotp_config.size = data->size;
+	ocotp_config.priv = otp;
+	ocotp_config.dev = dev;
+	otp->nvmem = devm_nvmem_register(dev, &ocotp_config);
+	if (IS_ERR(otp->nvmem))
+		return PTR_ERR(otp->nvmem);
+
+	platform_set_drvdata(pdev, otp);
+
+	return 0;
+}
+
+static struct platform_driver mxs_ocotp_driver = {
+	.probe = mxs_ocotp_probe,
+	.driver = {
+		.name = "mxs-ocotp",
+		.of_match_table = mxs_ocotp_match,
+	},
+};
+
+module_platform_driver(mxs_ocotp_driver);
+MODULE_AUTHOR("Stefan Wahren <wahrenst@gmx.net");
+MODULE_DESCRIPTION("driver for OCOTP in i.MX23/i.MX28");
+MODULE_LICENSE("GPL v2");