linux/drivers/nvmem/layerscape-sfp.c
Sean Anderson 943eadbdb1 nvmem: sfp: Use regmap
This converts the SFP driver to use regmap. This will allow easily
supporting devices with different endians. We disallow byte-level
access, as regmap_bulk_read doesn't support it (and it's unclear what
the correct result would be when we have an endianness difference).

Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20220429162701.2222-16-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-09 15:46:29 +02:00

104 lines
2.5 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Layerscape SFP driver
*
* Copyright (c) 2022 Michael Walle <michael@walle.cc>
*
*/
#include <linux/device.h>
#include <linux/io.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/nvmem-provider.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include <linux/regmap.h>
#define LAYERSCAPE_SFP_OTP_OFFSET 0x0200
struct layerscape_sfp_priv {
struct regmap *regmap;
};
struct layerscape_sfp_data {
int size;
enum regmap_endian endian;
};
static int layerscape_sfp_read(void *context, unsigned int offset, void *val,
size_t bytes)
{
struct layerscape_sfp_priv *priv = context;
return regmap_bulk_read(priv->regmap,
LAYERSCAPE_SFP_OTP_OFFSET + offset, val,
bytes / 4);
}
static struct nvmem_config layerscape_sfp_nvmem_config = {
.name = "fsl-sfp",
.reg_read = layerscape_sfp_read,
.word_size = 4,
.stride = 4,
};
static int layerscape_sfp_probe(struct platform_device *pdev)
{
const struct layerscape_sfp_data *data;
struct layerscape_sfp_priv *priv;
struct nvmem_device *nvmem;
struct regmap_config config = { 0 };
void __iomem *base;
priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(base))
return PTR_ERR(base);
data = device_get_match_data(&pdev->dev);
config.reg_bits = 32;
config.reg_stride = 4;
config.val_bits = 32;
config.val_format_endian = data->endian;
config.max_register = LAYERSCAPE_SFP_OTP_OFFSET + data->size - 4;
priv->regmap = devm_regmap_init_mmio(&pdev->dev, base, &config);
if (IS_ERR(priv->regmap))
return PTR_ERR(priv->regmap);
layerscape_sfp_nvmem_config.size = data->size;
layerscape_sfp_nvmem_config.dev = &pdev->dev;
layerscape_sfp_nvmem_config.priv = priv;
nvmem = devm_nvmem_register(&pdev->dev, &layerscape_sfp_nvmem_config);
return PTR_ERR_OR_ZERO(nvmem);
}
static const struct layerscape_sfp_data ls1028a_data = {
.size = 0x88,
.endian = REGMAP_ENDIAN_LITTLE,
};
static const struct of_device_id layerscape_sfp_dt_ids[] = {
{ .compatible = "fsl,ls1028a-sfp", .data = &ls1028a_data },
{},
};
MODULE_DEVICE_TABLE(of, layerscape_sfp_dt_ids);
static struct platform_driver layerscape_sfp_driver = {
.probe = layerscape_sfp_probe,
.driver = {
.name = "layerscape_sfp",
.of_match_table = layerscape_sfp_dt_ids,
},
};
module_platform_driver(layerscape_sfp_driver);
MODULE_AUTHOR("Michael Walle <michael@walle.cc>");
MODULE_DESCRIPTION("Layerscape Security Fuse Processor driver");
MODULE_LICENSE("GPL");