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Commit ded1b7fc authored by Fabrice Gasnier's avatar Fabrice Gasnier Committed by Greg Kroah-Hartman
Browse files

nvmem: Add driver for STM32 factory-programmed read only mem 



Add a read only nvmem driver for STM32 factory-programmed memory area
(on-chip non-volatile storage).

Signed-off-by: default avatarFabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: default avatarSrinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 4f4cb173

drivers/nvmem/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -113,6 +113,16 @@ config NVMEM_BCM_OCOTP 
	  This driver can also be built as a module. If so, the module

	  will be called nvmem-bcm-ocotp.



config NVMEM_STM32_ROMEM

	tristate "STMicroelectronics STM32 factory-programmed memory support"

	depends on ARCH_STM32 || COMPILE_TEST

	help

	  Say y here to enable read-only access for STMicroelectronics STM32

	  factory-programmed memory area.



	  This driver can also be built as a module. If so, the module

	  will be called nvmem-stm32-romem.



config NVMEM_SUNXI_SID

	tristate "Allwinner SoCs SID support"

	depends on ARCH_SUNXI

drivers/nvmem/Makefile

+2 −0
Original line number Diff line number Diff line
@@ -26,6 +26,8 @@ nvmem_qfprom-y := qfprom.o 
obj-$(CONFIG_ROCKCHIP_EFUSE)	+= nvmem_rockchip_efuse.o

nvmem_rockchip_efuse-y		:= rockchip-efuse.o

obj-$(CONFIG_NVMEM_SUNXI_SID)	+= nvmem_sunxi_sid.o

nvmem_stm32_romem-y 		:= stm32-romem.o

obj-$(CONFIG_NVMEM_STM32_ROMEM) += nvmem_stm32_romem.o

nvmem_sunxi_sid-y		:= sunxi_sid.o

obj-$(CONFIG_UNIPHIER_EFUSE)	+= nvmem-uniphier-efuse.o

nvmem-uniphier-efuse-y		:= uniphier-efuse.o

drivers/nvmem/stm32-romem.c

0 → 100644
+78 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/*

 * STM32 Factory-programmed memory read access driver

 *

 * Copyright (C) 2017, STMicroelectronics - All Rights Reserved

 * Author: Fabrice Gasnier <fabrice.gasnier@st.com> for STMicroelectronics.

 */



#include <linux/io.h>

#include <linux/module.h>

#include <linux/nvmem-provider.h>

#include <linux/of_device.h>



struct stm32_romem_priv {

	void __iomem *base;

	struct nvmem_config cfg;

};



static int stm32_romem_read(void *context, unsigned int offset, void *buf,

			    size_t bytes)

{

	struct stm32_romem_priv *priv = context;

	u8 *buf8 = buf;

	int i;



	for (i = offset; i < offset + bytes; i++)

		*buf8++ = readb_relaxed(priv->base + i);



	return 0;

}



static int stm32_romem_probe(struct platform_device *pdev)

{

	struct device *dev = &pdev->dev;

	struct stm32_romem_priv *priv;

	struct resource *res;



	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);



	priv->cfg.name = "stm32-romem";

	priv->cfg.read_only = true;

	priv->cfg.word_size = 1;

	priv->cfg.stride = 1;

	priv->cfg.size = resource_size(res);

	priv->cfg.reg_read = stm32_romem_read;

	priv->cfg.dev = dev;

	priv->cfg.priv = priv;

	priv->cfg.owner = THIS_MODULE;



	return PTR_ERR_OR_ZERO(devm_nvmem_register(dev, &priv->cfg));

}



static const struct of_device_id stm32_romem_of_match[] = {

	{ .compatible = "st,stm32f4-otp", },

	{},

};

MODULE_DEVICE_TABLE(of, stm32_romem_of_match);



static struct platform_driver stm32_romem_driver = {

	.probe = stm32_romem_probe,

	.driver = {

		.name = "stm32-romem",

		.of_match_table = of_match_ptr(stm32_romem_of_match),

	},

};

module_platform_driver(stm32_romem_driver);



MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>");

MODULE_DESCRIPTION("STMicroelectronics STM32 RO-MEM");

MODULE_ALIAS("platform:nvmem-stm32-romem");

MODULE_LICENSE("GPL v2");