From 3edba6b47e4265948db3a77a0137157c033d69e2 Mon Sep 17 00:00:00 2001
From: Philipp Zabel
Date: Wed, 30 Sep 2015 13:55:47 +0100
Subject: [PATCH] nvmem: imx-ocotp: Add i.MX6 OCOTP driver
This driver handles the i.MX On-Chip OTP Controller found in
i.MX6Q/D, i.MX6S/DL, i.MX6SL, and i.MX6SX SoCs. Currently it
just returns the values stored in the shadow registers.
Signed-off-by: Philipp Zabel
Acked-by: Srinivas Kandagatla
Signed-off-by: Srinivas Kandagatla
Signed-off-by: Greg Kroah-Hartman
---
drivers/nvmem/Kconfig | 11 ++++
drivers/nvmem/Makefile | 2 +
drivers/nvmem/imx-ocotp.c | 154 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 167 insertions(+)
create mode 100644 drivers/nvmem/imx-ocotp.c
diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
index 1d4f2b4..208a1cb 100644
--- a/drivers/nvmem/Kconfig
+++ b/drivers/nvmem/Kconfig
@@ -14,6 +14,17 @@ menuconfig NVMEM
if NVMEM
+config NVMEM_IMX_OCOTP
+ tristate "i.MX6 On-Chip OTP Controller support"
+ depends on SOC_IMX6
+ help
+ This is a driver for the On-Chip OTP Controller (OCOTP) available on
+ i.MX6 SoCs, providing access to 4 Kbits of one-time programmable
+ eFuses.
+
+ This driver can also be built as a module. If so, the module
+ will be called nvmem-imx-ocotp.
+
config QCOM_QFPROM
tristate "QCOM QFPROM Support"
depends on ARCH_QCOM || COMPILE_TEST
diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile
index 3bdcfd4..2ddf0e8 100644
--- a/drivers/nvmem/Makefile
+++ b/drivers/nvmem/Makefile
@@ -6,6 +6,8 @@ obj-$(CONFIG_NVMEM) += nvmem_core.o
nvmem_core-y := core.o
# Devices
+obj-$(CONFIG_NVMEM_IMX_OCOTP) += nvmem-imx-ocotp.o
+nvmem-imx-ocotp-y := imx-ocotp.o
obj-$(CONFIG_QCOM_QFPROM) += nvmem_qfprom.o
nvmem_qfprom-y := qfprom.o
obj-$(CONFIG_NVMEM_SUNXI_SID) += nvmem_sunxi_sid.o
diff --git a/drivers/nvmem/imx-ocotp.c b/drivers/nvmem/imx-ocotp.c
new file mode 100644
index 0000000..b7971d4
--- /dev/null
+++ b/drivers/nvmem/imx-ocotp.c
@@ -0,0 +1,154 @@
+/*
+ * i.MX6 OCOTP fusebox driver
+ *
+ * Copyright (c) 2015 Pengutronix, Philipp Zabel
+ *
+ * Based on the barebox ocotp driver,
+ * Copyright (c) 2010 Baruch Siach ,
+ * Orex Computed Radiography
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+
+struct ocotp_priv {
+ struct device *dev;
+ void __iomem *base;
+ unsigned int nregs;
+};
+
+static int imx_ocotp_read(void *context, const void *reg, size_t reg_size,
+ void *val, size_t val_size)
+{
+ struct ocotp_priv *priv = context;
+ unsigned int offset = *(u32 *)reg;
+ unsigned int count;
+ int i;
+ u32 index;
+
+ index = offset >> 2;
+ count = val_size >> 2;
+
+ if (count > (priv->nregs - index))
+ count = priv->nregs - index;
+
+ for (i = index; i < (index + count); i++) {
+ *(u32 *)val = readl(priv->base + 0x400 + i * 0x10);
+ val += 4;
+ }
+
+ return (i - index) * 4;
+}
+
+static int imx_ocotp_write(void *context, const void *data, size_t count)
+{
+ /* Not implemented */
+ return 0;
+}
+
+static struct regmap_bus imx_ocotp_bus = {
+ .read = imx_ocotp_read,
+ .write = imx_ocotp_write,
+ .reg_format_endian_default = REGMAP_ENDIAN_NATIVE,
+ .val_format_endian_default = REGMAP_ENDIAN_NATIVE,
+};
+
+static bool imx_ocotp_writeable_reg(struct device *dev, unsigned int reg)
+{
+ return false;
+}
+
+static struct regmap_config imx_ocotp_regmap_config = {
+ .reg_bits = 32,
+ .val_bits = 32,
+ .reg_stride = 4,
+ .writeable_reg = imx_ocotp_writeable_reg,
+ .name = "imx-ocotp",
+};
+
+static struct nvmem_config imx_ocotp_nvmem_config = {
+ .name = "imx-ocotp",
+ .read_only = true,
+ .owner = THIS_MODULE,
+};
+
+static const struct of_device_id imx_ocotp_dt_ids[] = {
+ { .compatible = "fsl,imx6q-ocotp", (void *)128 },
+ { .compatible = "fsl,imx6sl-ocotp", (void *)32 },
+ { .compatible = "fsl,imx6sx-ocotp", (void *)128 },
+ { },
+};
+MODULE_DEVICE_TABLE(of, imx_ocotp_dt_ids);
+
+static int imx_ocotp_probe(struct platform_device *pdev)
+{
+ const struct of_device_id *of_id;
+ struct device *dev = &pdev->dev;
+ struct resource *res;
+ struct regmap *regmap;
+ struct ocotp_priv *priv;
+ struct nvmem_device *nvmem;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ priv->base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(priv->base))
+ return PTR_ERR(priv->base);
+
+ of_id = of_match_device(imx_ocotp_dt_ids, dev);
+ priv->nregs = (unsigned int)of_id->data;
+ imx_ocotp_regmap_config.max_register = 4 * priv->nregs - 4;
+
+ regmap = devm_regmap_init(dev, &imx_ocotp_bus, priv,
+ &imx_ocotp_regmap_config);
+ if (IS_ERR(regmap)) {
+ dev_err(dev, "regmap init failed\n");
+ return PTR_ERR(regmap);
+ }
+ imx_ocotp_nvmem_config.dev = dev;
+ nvmem = nvmem_register(&imx_ocotp_nvmem_config);
+ if (IS_ERR(nvmem))
+ return PTR_ERR(nvmem);
+
+ platform_set_drvdata(pdev, nvmem);
+
+ return 0;
+}
+
+static int imx_ocotp_remove(struct platform_device *pdev)
+{
+ struct nvmem_device *nvmem = platform_get_drvdata(pdev);
+
+ return nvmem_unregister(nvmem);
+}
+
+static struct platform_driver imx_ocotp_driver = {
+ .probe = imx_ocotp_probe,
+ .remove = imx_ocotp_remove,
+ .driver = {
+ .name = "imx_ocotp",
+ .of_match_table = imx_ocotp_dt_ids,
+ },
+};
+module_platform_driver(imx_ocotp_driver);
+
+MODULE_AUTHOR("Philipp Zabel ");
+MODULE_DESCRIPTION("i.MX6 OCOTP fuse box driver");
+MODULE_LICENSE("GPL v2");
--
2.7.4