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: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Fabrice Gasnier 2019-04-13 11:32:55 +01:00 committed by Greg Kroah-Hartman
parent 4f4cb173d8
commit ded1b7fc2c
3 changed files with 90 additions and 0 deletions

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@ -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

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@ -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

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@ -0,0 +1,78 @@
// 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");