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// SPDX-License-Identifier: GPL-2.0-only
/*
* Amlogic Meson GX eFuse Driver
*
* Copyright (c) 2016 Endless Computers, Inc.
* Author: Carlo Caione <carlo@endlessm.com>
*/
#include <linux/clk.h>
#include <linux/module.h>
#include <linux/nvmem-provider.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/firmware/meson/meson_sm.h>
static int meson_efuse_read(void *context, unsigned int offset,
void *val, size_t bytes)
{
struct meson_sm_firmware *fw = context;
return meson_sm_call_read(fw, (u8 *)val, bytes, SM_EFUSE_READ, offset,
bytes, 0, 0, 0);
}
static int meson_efuse_write(void *context, unsigned int offset,
void *val, size_t bytes)
{
struct meson_sm_firmware *fw = context;
return meson_sm_call_write(fw, (u8 *)val, bytes, SM_EFUSE_WRITE, offset,
bytes, 0, 0, 0);
}
static const struct of_device_id meson_efuse_match[] = {
{ .compatible = "amlogic,meson-gxbb-efuse", },
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, meson_efuse_match);
static int meson_efuse_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct meson_sm_firmware *fw;
struct device_node *sm_np;
struct nvmem_device *nvmem;
struct nvmem_config *econfig;
struct clk *clk;
unsigned int size;
int ret;
sm_np = of_parse_phandle(pdev->dev.of_node, "secure-monitor", 0);
if (!sm_np) {
dev_err(&pdev->dev, "no secure-monitor node\n");
return -ENODEV;
}
fw = meson_sm_get(sm_np);
of_node_put(sm_np);
if (!fw)
return -EPROBE_DEFER;
clk = devm_clk_get(dev, NULL);
if (IS_ERR(clk)) {
ret = PTR_ERR(clk);
if (ret != -EPROBE_DEFER)
dev_err(dev, "failed to get efuse gate");
return ret;
}
ret = clk_prepare_enable(clk);
if (ret) {
dev_err(dev, "failed to enable gate");
return ret;
}
ret = devm_add_action_or_reset(dev,
(void(*)(void *))clk_disable_unprepare,
clk);
if (ret) {
dev_err(dev, "failed to add disable callback");
return ret;
}
if (meson_sm_call(fw, SM_EFUSE_USER_MAX, &size, 0, 0, 0, 0, 0) < 0) {
dev_err(dev, "failed to get max user");
return -EINVAL;
}
econfig = devm_kzalloc(dev, sizeof(*econfig), GFP_KERNEL);
if (!econfig)
return -ENOMEM;
econfig->dev = dev;
econfig->name = dev_name(dev);
econfig->add_legacy_fixed_of_cells = true;
econfig->stride = 1;
econfig->word_size = 1;
econfig->reg_read = meson_efuse_read;
econfig->reg_write = meson_efuse_write;
econfig->size = size;
econfig->priv = fw;
nvmem = devm_nvmem_register(&pdev->dev, econfig);
return PTR_ERR_OR_ZERO(nvmem);
}
static struct platform_driver meson_efuse_driver = {
.probe = meson_efuse_probe,
.driver = {
.name = "meson-efuse",
.of_match_table = meson_efuse_match,
},
};
module_platform_driver(meson_efuse_driver);
MODULE_AUTHOR("Carlo Caione <carlo@endlessm.com>");
MODULE_DESCRIPTION("Amlogic Meson GX NVMEM driver");
MODULE_LICENSE("GPL v2");
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