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99 lines
2.2 KiB
99 lines
2.2 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* sfr.c - driver for special function registers |
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* |
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* Copyright (C) 2019 Bootlin. |
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* |
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*/ |
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#include <linux/mfd/syscon.h> |
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#include <linux/module.h> |
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#include <linux/nvmem-provider.h> |
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#include <linux/random.h> |
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#include <linux/of.h> |
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#include <linux/of_device.h> |
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#include <linux/platform_device.h> |
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#include <linux/regmap.h> |
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#define SFR_SN0 0x4c |
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#define SFR_SN_SIZE 8 |
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struct atmel_sfr_priv { |
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struct regmap *regmap; |
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}; |
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static int atmel_sfr_read(void *context, unsigned int offset, |
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void *buf, size_t bytes) |
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{ |
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struct atmel_sfr_priv *priv = context; |
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return regmap_bulk_read(priv->regmap, SFR_SN0 + offset, |
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buf, bytes / 4); |
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} |
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static struct nvmem_config atmel_sfr_nvmem_config = { |
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.name = "atmel-sfr", |
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.read_only = true, |
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.word_size = 4, |
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.stride = 4, |
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.size = SFR_SN_SIZE, |
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.reg_read = atmel_sfr_read, |
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}; |
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static int atmel_sfr_probe(struct platform_device *pdev) |
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{ |
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struct device *dev = &pdev->dev; |
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struct device_node *np = dev->of_node; |
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struct nvmem_device *nvmem; |
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struct atmel_sfr_priv *priv; |
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u8 sn[SFR_SN_SIZE]; |
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int ret; |
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priv = devm_kmalloc(dev, sizeof(*priv), GFP_KERNEL); |
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if (!priv) |
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return -ENOMEM; |
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priv->regmap = syscon_node_to_regmap(np); |
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if (IS_ERR(priv->regmap)) { |
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dev_err(dev, "cannot get parent's regmap\n"); |
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return PTR_ERR(priv->regmap); |
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} |
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atmel_sfr_nvmem_config.dev = dev; |
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atmel_sfr_nvmem_config.priv = priv; |
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nvmem = devm_nvmem_register(dev, &atmel_sfr_nvmem_config); |
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if (IS_ERR(nvmem)) { |
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dev_err(dev, "error registering nvmem config\n"); |
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return PTR_ERR(nvmem); |
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} |
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ret = atmel_sfr_read(priv, 0, sn, SFR_SN_SIZE); |
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if (ret == 0) |
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add_device_randomness(sn, SFR_SN_SIZE); |
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return ret; |
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} |
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static const struct of_device_id atmel_sfr_dt_ids[] = { |
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{ |
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.compatible = "atmel,sama5d2-sfr", |
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}, { |
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.compatible = "atmel,sama5d4-sfr", |
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}, { |
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/* sentinel */ |
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}, |
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}; |
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MODULE_DEVICE_TABLE(of, atmel_sfr_dt_ids); |
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static struct platform_driver atmel_sfr_driver = { |
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.probe = atmel_sfr_probe, |
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.driver = { |
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.name = "atmel-sfr", |
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.of_match_table = atmel_sfr_dt_ids, |
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}, |
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}; |
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module_platform_driver(atmel_sfr_driver); |
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MODULE_AUTHOR("Kamel Bouhara <[email protected]>"); |
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MODULE_DESCRIPTION("Atmel SFR SN driver for SAMA5D2/4 SoC family"); |
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MODULE_LICENSE("GPL v2");
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