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