3 files changed, 136 insertions, 0 deletions

diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
index ba140eaee5c8..605524c93e45 100644
--- a/drivers/nvmem/Kconfig
+++ b/drivers/nvmem/Kconfig
@@ -35,6 +35,16 @@ config NVMEM_LPC18XX_EEPROM
           To compile this driver as a module, choose M here: the module
           will be called nvmem_lpc18xx_eeprom.
 
+config NVMEM_LPC18XX_OTP
+        tristate "NXP LPC18XX OTP Memory Support"
+        depends on ARCH_LPC18XX || COMPILE_TEST
+        depends on HAS_IOMEM
+        help
+          Say Y here to include support for NXP LPC18xx OTP memory found on
+          all LPC18xx and LPC43xx devices.
+          To compile this driver as a module, choose M here: the module
+          will be called nvmem_lpc18xx_otp.
+
 config NVMEM_MXS_OCOTP
         tristate "Freescale MXS On-Chip OTP Memory Support"
         depends on ARCH_MXS || COMPILE_TEST
diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile
index 8f942a0cdaec..b2d31950ce58 100644
--- a/drivers/nvmem/Makefile
+++ b/drivers/nvmem/Makefile
@@ -10,6 +10,8 @@ obj-$(CONFIG_NVMEM_IMX_OCOTP)	+= nvmem-imx-ocotp.o
 nvmem-imx-ocotp-y               := imx-ocotp.o
 obj-$(CONFIG_NVMEM_LPC18XX_EEPROM)      += nvmem_lpc18xx_eeprom.o
 nvmem_lpc18xx_eeprom-y  := lpc18xx_eeprom.o
+obj-$(CONFIG_NVMEM_LPC18XX_OTP) += nvmem_lpc18xx_otp.o
+nvmem_lpc18xx_otp-y             := lpc18xx_otp.o
 obj-$(CONFIG_NVMEM_MXS_OCOTP)   += nvmem-mxs-ocotp.o
 nvmem-mxs-ocotp-y               := mxs-ocotp.o
 obj-$(CONFIG_MTK_EFUSE)         += nvmem_mtk-efuse.o
diff --git a/drivers/nvmem/lpc18xx_otp.c b/drivers/nvmem/lpc18xx_otp.c
new file mode 100644
index 000000000000..be8d07403ffc
--- /dev/null
+++ b/drivers/nvmem/lpc18xx_otp.c
@@ -0,0 +1,124 @@
+/*
+ * NXP LPC18xx/43xx OTP memory NVMEM driver
+ *
+ * Copyright (c) 2016 Joachim Eastwood <manabian@gmail.com>
+ *
+ * Based on the imx ocotp driver,
+ * Copyright (c) 2015 Pengutronix, Philipp Zabel <p.zabel@pengutronix.de>
+ *
+ * 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.
+ *
+ * TODO: add support for writing OTP register via API in boot ROM.
+ */
+
+#include <linux/io.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>
+
+/*
+ * LPC18xx OTP memory contains 4 banks with 4 32-bit words. Bank 0 starts
+ * at offset 0 from the base.
+ *
+ * Bank 0 contains the part ID for Flashless devices and is reseverd for
+ * devices with Flash.
+ * Bank 1/2 is generale purpose or AES key storage for secure devices.
+ * Bank 3 contains control data, USB ID and generale purpose words.
+ */
+#define LPC18XX_OTP_NUM_BANKS           4
+#define LPC18XX_OTP_WORDS_PER_BANK      4
+#define LPC18XX_OTP_WORD_SIZE           sizeof(u32)
+#define LPC18XX_OTP_SIZE                (LPC18XX_OTP_NUM_BANKS * \
+                                         LPC18XX_OTP_WORDS_PER_BANK * \
+                                         LPC18XX_OTP_WORD_SIZE)
+
+struct lpc18xx_otp {
+        void __iomem *base;
+};
+
+static int lpc18xx_otp_read(void *context, unsigned int offset,
+                            void *val, size_t bytes)
+{
+        struct lpc18xx_otp *otp = context;
+        unsigned int count = bytes >> 2;
+        u32 index = offset >> 2;
+        u32 *buf = val;
+        int i;
+
+        if (count > (LPC18XX_OTP_SIZE - index))
+                count = LPC18XX_OTP_SIZE - index;
+
+        for (i = index; i < (index + count); i++)
+                *buf++ = readl(otp->base + i * LPC18XX_OTP_WORD_SIZE);
+
+        return 0;
+}
+
+static struct nvmem_config lpc18xx_otp_nvmem_config = {
+        .name = "lpc18xx-otp",
+        .read_only = true,
+        .word_size = LPC18XX_OTP_WORD_SIZE,
+        .stride = LPC18XX_OTP_WORD_SIZE,
+        .owner = THIS_MODULE,
+        .reg_read = lpc18xx_otp_read,
+};
+
+static int lpc18xx_otp_probe(struct platform_device *pdev)
+{
+        struct nvmem_device *nvmem;
+        struct lpc18xx_otp *otp;
+        struct resource *res;
+
+        otp = devm_kzalloc(&pdev->dev, sizeof(*otp), GFP_KERNEL);
+        if (!otp)
+                return -ENOMEM;
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        otp->base = devm_ioremap_resource(&pdev->dev, res);
+        if (IS_ERR(otp->base))
+                return PTR_ERR(otp->base);
+
+        lpc18xx_otp_nvmem_config.size = LPC18XX_OTP_SIZE;
+        lpc18xx_otp_nvmem_config.dev = &pdev->dev;
+        lpc18xx_otp_nvmem_config.priv = otp;
+
+        nvmem = nvmem_register(&lpc18xx_otp_nvmem_config);
+        if (IS_ERR(nvmem))
+                return PTR_ERR(nvmem);
+
+        platform_set_drvdata(pdev, nvmem);
+
+        return 0;
+}
+
+static int lpc18xx_otp_remove(struct platform_device *pdev)
+{
+        struct nvmem_device *nvmem = platform_get_drvdata(pdev);
+
+        return nvmem_unregister(nvmem);
+}
+
+static const struct of_device_id lpc18xx_otp_dt_ids[] = {
+        { .compatible = "nxp,lpc1850-otp" },
+        { },
+};
+MODULE_DEVICE_TABLE(of, lpc18xx_otp_dt_ids);
+
+static struct platform_driver lpc18xx_otp_driver = {
+        .probe  = lpc18xx_otp_probe,
+        .remove = lpc18xx_otp_remove,
+        .driver = {
+                .name   = "lpc18xx_otp",
+                .of_match_table = lpc18xx_otp_dt_ids,
+        },
+};
+module_platform_driver(lpc18xx_otp_driver);
+
+MODULE_AUTHOR("Joachim Eastwoood <manabian@gmail.com>");
+MODULE_DESCRIPTION("NXP LPC18xx OTP NVMEM driver");
+MODULE_LICENSE("GPL v2");