linux/drivers/nvmem/meson-efuse.c
Joy Chakraborty dfa728e059 nvmem: meson-efuse: Fix return value of nvmem callbacks
commit 7a0a6d0a7c upstream.

Read/write callbacks registered with nvmem core expect 0 to be returned
on success and a negative value to be returned on failure.

meson_efuse_read() and meson_efuse_write() call into
meson_sm_call_read() and meson_sm_call_write() respectively which return
the number of bytes read or written on success as per their api
description.

Fix to return error if meson_sm_call_read()/meson_sm_call_write()
returns an error else return 0.

Fixes: a29a63bdaf ("nvmem: meson-efuse: simplify read callback")
Cc: stable@vger.kernel.org
Signed-off-by: Joy Chakraborty <joychakr@google.com>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20240628113704.13742-3-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-18 13:18:40 +02:00

108 lines
2.5 KiB
C

// 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;
int ret;
ret = meson_sm_call_read(fw, (u8 *)val, bytes, SM_EFUSE_READ, offset,
bytes, 0, 0, 0);
return ret < 0 ? ret : 0;
}
static int meson_efuse_write(void *context, unsigned int offset,
void *val, size_t bytes)
{
struct meson_sm_firmware *fw = context;
int ret;
ret = meson_sm_call_write(fw, (u8 *)val, bytes, SM_EFUSE_WRITE, offset,
bytes, 0, 0, 0);
return ret < 0 ? ret : 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;
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_enabled(dev, NULL);
if (IS_ERR(clk))
return dev_err_probe(dev, PTR_ERR(clk), "failed to get efuse gate");
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->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");