79 lines
1.9 KiB
C
79 lines
1.9 KiB
C
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// SPDX-License-Identifier: GPL-2.0
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/*
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* STM32 Factory-programmed memory read access driver
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*
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* Copyright (C) 2017, STMicroelectronics - All Rights Reserved
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* Author: Fabrice Gasnier <fabrice.gasnier@st.com> for STMicroelectronics.
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*/
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#include <linux/io.h>
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#include <linux/module.h>
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#include <linux/nvmem-provider.h>
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#include <linux/of_device.h>
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struct stm32_romem_priv {
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void __iomem *base;
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struct nvmem_config cfg;
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};
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static int stm32_romem_read(void *context, unsigned int offset, void *buf,
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size_t bytes)
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{
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struct stm32_romem_priv *priv = context;
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u8 *buf8 = buf;
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int i;
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for (i = offset; i < offset + bytes; i++)
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*buf8++ = readb_relaxed(priv->base + i);
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return 0;
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}
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static int stm32_romem_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct stm32_romem_priv *priv;
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struct resource *res;
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priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
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if (!priv)
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return -ENOMEM;
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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priv->base = devm_ioremap_resource(dev, res);
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if (IS_ERR(priv->base))
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return PTR_ERR(priv->base);
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priv->cfg.name = "stm32-romem";
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priv->cfg.read_only = true;
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priv->cfg.word_size = 1;
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priv->cfg.stride = 1;
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priv->cfg.size = resource_size(res);
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priv->cfg.reg_read = stm32_romem_read;
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priv->cfg.dev = dev;
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priv->cfg.priv = priv;
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priv->cfg.owner = THIS_MODULE;
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return PTR_ERR_OR_ZERO(devm_nvmem_register(dev, &priv->cfg));
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}
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static const struct of_device_id stm32_romem_of_match[] = {
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{ .compatible = "st,stm32f4-otp", },
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{},
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};
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MODULE_DEVICE_TABLE(of, stm32_romem_of_match);
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static struct platform_driver stm32_romem_driver = {
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.probe = stm32_romem_probe,
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.driver = {
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.name = "stm32-romem",
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.of_match_table = of_match_ptr(stm32_romem_of_match),
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},
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};
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module_platform_driver(stm32_romem_driver);
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MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>");
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MODULE_DESCRIPTION("STMicroelectronics STM32 RO-MEM");
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MODULE_ALIAS("platform:nvmem-stm32-romem");
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MODULE_LICENSE("GPL v2");
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