From ded1b7fc2cf5a4ae3b902b0e46f592ab724b7828 Mon Sep 17 00:00:00 2001 From: Fabrice Gasnier Date: Sat, 13 Apr 2019 11:32:55 +0100 Subject: [PATCH] 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 Signed-off-by: Srinivas Kandagatla Signed-off-by: Greg Kroah-Hartman --- drivers/nvmem/Kconfig | 10 +++++ drivers/nvmem/Makefile | 2 + drivers/nvmem/stm32-romem.c | 78 +++++++++++++++++++++++++++++++++++++ 3 files changed, 90 insertions(+) create mode 100644 drivers/nvmem/stm32-romem.c diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig index 9e1d83643e9c..a90e9a1ebe55 100644 --- a/drivers/nvmem/Kconfig +++ b/drivers/nvmem/Kconfig @@ -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 diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile index 2ece8ffffdda..4c7ba12a7005 100644 --- a/drivers/nvmem/Makefile +++ b/drivers/nvmem/Makefile @@ -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 diff --git a/drivers/nvmem/stm32-romem.c b/drivers/nvmem/stm32-romem.c new file mode 100644 index 000000000000..07e98b53b391 --- /dev/null +++ b/drivers/nvmem/stm32-romem.c @@ -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 for STMicroelectronics. + */ + +#include +#include +#include +#include + +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 "); +MODULE_DESCRIPTION("STMicroelectronics STM32 RO-MEM"); +MODULE_ALIAS("platform:nvmem-stm32-romem"); +MODULE_LICENSE("GPL v2"); -- 2.30.2