[PATCH 0/3] nvmem: add lpc18xx OTP memory driver

[PATCH 0/3] nvmem: add lpc18xx OTP memory driver

[Joachim Eastwood]

This patch set adds a simple read-only nvmem driver for the
internal OTP (One Time Programmable) memory found on all
LPC18xx/43xx devices. Write support is coming later when
the required firmware driver for the boot ROM goes upstream.

Note that dtsi patch is only included for reference. I intend
to take it myself through the lpc18xx tree once the bindings
are accepted and the driver goes upstream.


Joachim Eastwood (3):
  nvmem: add NXP LPC18xx OTP driver
  nvmem: dt: document lpc1850 OTP binding
  ARM: dts: lpc18xx: add otp node

 .../devicetree/bindings/nvmem/lpc1850-otp.txt      |  20 ++++
 arch/arm/boot/dts/lpc18xx.dtsi                     |  12 ++
 drivers/nvmem/Kconfig                              |  10 ++
 drivers/nvmem/Makefile                             |   2 +
 drivers/nvmem/lpc18xx_otp.c                        | 123 +++++++++++++++++++++
 5 files changed, 167 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/nvmem/lpc1850-otp.txt
 create mode 100644 drivers/nvmem/lpc18xx_otp.c

-- 
2.9.3

[PATCH 1/3] nvmem: add NXP LPC18xx OTP driver

[Joachim Eastwood]

Add simple read only driver for the internal OTP (One Time Programmable)
memory found on all NXP LPC18xx and LPC43xx devices.

The OTP memory is split into 4 banks each with 4 32-bits word. Some of
the banks contain predefined data while others are for general purpose
and user programmable via the OTP API in ROM. Note that writing to the
OTP memory is not yet supported.

Signed-off-by: Joachim Eastwood <manabian@gmail.com>
---
 drivers/nvmem/Kconfig       |  10 ++++
 drivers/nvmem/Makefile      |   2 +
 drivers/nvmem/lpc18xx_otp.c | 123 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 135 insertions(+)
 create mode 100644 drivers/nvmem/lpc18xx_otp.c

diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
index f550c45..282037b 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 45ab1ae..df485a9 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 0000000..b78ed0b
--- /dev/null
+++ b/drivers/nvmem/lpc18xx_otp.c
@@ -0,0 +1,123 @@
+/*
+ * 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");
-- 
2.9.3

[PATCH 1/3] nvmem: add NXP LPC18xx OTP driver

[Srinivas Kandagatla]

On 13/09/16 17:12, Joachim Eastwood wrote:
> Add simple read only driver for the internal OTP (One Time Programmable)
> memory found on all NXP LPC18xx and LPC43xx devices.
>
> The OTP memory is split into 4 banks each with 4 32-bits word. Some of
> the banks contain predefined data while others are for general purpose
> and user programmable via the OTP API in ROM. Note that writing to the
> OTP memory is not yet supported.
>
> Signed-off-by: Joachim Eastwood <manabian@gmail.com>
> ---
>  drivers/nvmem/Kconfig       |  10 ++++
>  drivers/nvmem/Makefile      |   2 +
>  drivers/nvmem/lpc18xx_otp.c | 123 ++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 135 insertions(+)
>  create mode 100644 drivers/nvmem/lpc18xx_otp.c
>

Patch looks good to me.

I will pick this patch + bindings patch once rc1 lands in.

Thanks,
srini

[PATCH 1/3] nvmem: add NXP LPC18xx OTP driver

[Vladimir Zapolskiy]

Hi Joachim, Srinivas,

On 13.09.2016 19:12, Joachim Eastwood wrote:
> Add simple read only driver for the internal OTP (One Time Programmable)
> memory found on all NXP LPC18xx and LPC43xx devices.
> 
> The OTP memory is split into 4 banks each with 4 32-bits word. Some of
> the banks contain predefined data while others are for general purpose
> and user programmable via the OTP API in ROM. Note that writing to the
> OTP memory is not yet supported.
> 
> Signed-off-by: Joachim Eastwood <manabian@gmail.com>
> ---

please feel free to add my

  Tested-by: Vladimir Zapolskiy <vz@mleia.com>

--
With best wishes,
Vladimir

[PATCH 1/3] nvmem: add NXP LPC18xx OTP driver

[Joachim Eastwood]

Hi Vladimir,

On 7 October 2016 at 03:44, Vladimir Zapolskiy <vz@mleia.com> wrote:
> Hi Joachim, Srinivas,
>
> On 13.09.2016 19:12, Joachim Eastwood wrote:
>> Add simple read only driver for the internal OTP (One Time Programmable)
>> memory found on all NXP LPC18xx and LPC43xx devices.
>>
>> The OTP memory is split into 4 banks each with 4 32-bits word. Some of
>> the banks contain predefined data while others are for general purpose
>> and user programmable via the OTP API in ROM. Note that writing to the
>> OTP memory is not yet supported.
>>
>> Signed-off-by: Joachim Eastwood <manabian@gmail.com>
>> ---
>
> please feel free to add my
>
>   Tested-by: Vladimir Zapolskiy <vz@mleia.com>

Thanks for testing!


regards,
Joachim Eastwood

[PATCH 2/3] nvmem: dt: document lpc1850 OTP binding

[Joachim Eastwood]

Documenation for the LPC18xx/43xx OTP memory bindings.

Signed-off-by: Joachim Eastwood <manabian@gmail.com>
---
 .../devicetree/bindings/nvmem/lpc1850-otp.txt        | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/nvmem/lpc1850-otp.txt

diff --git a/Documentation/devicetree/bindings/nvmem/lpc1850-otp.txt b/Documentation/devicetree/bindings/nvmem/lpc1850-otp.txt
new file mode 100644
index 0000000..853b6a7
--- /dev/null
+++ b/Documentation/devicetree/bindings/nvmem/lpc1850-otp.txt
@@ -0,0 +1,20 @@
+* NXP LPC18xx OTP memory
+
+Internal OTP (One Time Programmable) memory for NXP LPC18xx/43xx devices.
+
+Required properties:
+  - compatible: Should be "nxp,lpc1850-otp"
+  - reg: Must contain an entry with the physical base address and length
+    for each entry in reg-names.
+  - address-cells: must be set to 1.
+  - size-cells: must be set to 1.
+
+See nvmem.txt for more information.
+
+Example:
+  otp: otp at 40045000 {
+    compatible = "nxp,lpc1850-otp";
+    reg = <0x40045000 0x1000>;
+    #address-cells = <1>;
+    #size-cells = <1>;
+  };
-- 
2.9.3

[PATCH 2/3] nvmem: dt: document lpc1850 OTP binding

[Rob Herring]

On Tue, Sep 13, 2016 at 06:12:40PM +0200, Joachim Eastwood wrote:
> Documenation for the LPC18xx/43xx OTP memory bindings.
> 
> Signed-off-by: Joachim Eastwood <manabian@gmail.com>
> ---
>  .../devicetree/bindings/nvmem/lpc1850-otp.txt        | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/nvmem/lpc1850-otp.txt
> 
> diff --git a/Documentation/devicetree/bindings/nvmem/lpc1850-otp.txt b/Documentation/devicetree/bindings/nvmem/lpc1850-otp.txt
> new file mode 100644
> index 0000000..853b6a7
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/nvmem/lpc1850-otp.txt
> @@ -0,0 +1,20 @@
> +* NXP LPC18xx OTP memory
> +
> +Internal OTP (One Time Programmable) memory for NXP LPC18xx/43xx devices.
> +
> +Required properties:
> +  - compatible: Should be "nxp,lpc1850-otp"
> +  - reg: Must contain an entry with the physical base address and length
> +    for each entry in reg-names.

> +  - address-cells: must be set to 1.
> +  - size-cells: must be set to 1.

Not needed unless you have child nodes.

> +
> +See nvmem.txt for more information.
> +
> +Example:
> +  otp: otp at 40045000 {
> +    compatible = "nxp,lpc1850-otp";
> +    reg = <0x40045000 0x1000>;
> +    #address-cells = <1>;
> +    #size-cells = <1>;
> +  };
> -- 
> 2.9.3
> 

[PATCH 2/3] nvmem: dt: document lpc1850 OTP binding

[Joachim Eastwood]

On 23 September 2016 at 15:35, Rob Herring <robh@kernel.org> wrote:
> On Tue, Sep 13, 2016 at 06:12:40PM +0200, Joachim Eastwood wrote:
>> Documenation for the LPC18xx/43xx OTP memory bindings.
>>
>> Signed-off-by: Joachim Eastwood <manabian@gmail.com>
>> ---
>>  .../devicetree/bindings/nvmem/lpc1850-otp.txt        | 20 ++++++++++++++++++++
>>  1 file changed, 20 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/nvmem/lpc1850-otp.txt
>>
>> diff --git a/Documentation/devicetree/bindings/nvmem/lpc1850-otp.txt b/Documentation/devicetree/bindings/nvmem/lpc1850-otp.txt
>> new file mode 100644
>> index 0000000..853b6a7
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/nvmem/lpc1850-otp.txt
>> @@ -0,0 +1,20 @@
>> +* NXP LPC18xx OTP memory
>> +
>> +Internal OTP (One Time Programmable) memory for NXP LPC18xx/43xx devices.
>> +
>> +Required properties:
>> +  - compatible: Should be "nxp,lpc1850-otp"
>> +  - reg: Must contain an entry with the physical base address and length
>> +    for each entry in reg-names.
>
>> +  - address-cells: must be set to 1.
>> +  - size-cells: must be set to 1.
>
> Not needed unless you have child nodes.

They will have "nvmem" cell children. See patch 3/3

+                       /* Flashless devices has part ID in OTP bank 0 */
+                       part_id: identification at 0 {
+                               reg = <0x0 0x10>;
+                       };

These cells are documented in nvmem.txt.


regards,
Joachim Eastwood

[PATCH 3/3] ARM: dts: lpc18xx: add otp node

[Joachim Eastwood]

Add node for the internal OTP (One Time Programmable) memory found
on all LPC18xx/43xx SoCs.

Signed-off-by: Joachim Eastwood <manabian@gmail.com>
---
 arch/arm/boot/dts/lpc18xx.dtsi | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/arch/arm/boot/dts/lpc18xx.dtsi b/arch/arm/boot/dts/lpc18xx.dtsi
index c6508ed..7ef0bc8 100644
--- a/arch/arm/boot/dts/lpc18xx.dtsi
+++ b/arch/arm/boot/dts/lpc18xx.dtsi
@@ -250,6 +250,18 @@
 			};
 		};
 
+		otp at 40045000 {
+			compatible = "nxp,lpc1850-otp";
+			reg = <0x40045000 0x1000>;
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			/* Flashless devices has part ID in OTP bank 0 */
+			part_id: identification at 0 {
+				reg = <0x0 0x10>;
+			};
+		};
+
 		rtc: rtc at 40046000 {
 			compatible = "nxp,lpc1850-rtc", "nxp,lpc1788-rtc";
 			reg = <0x40046000 0x1000>;
-- 
2.9.3