linux-stable/drivers/nvmem/qfprom.c
Srinivas Kandagatla 992ba3f7b8 nvmem: qfprom: remove incorrect write support
commit 8d9eb0d6d5 upstream.

qfprom has different address spaces for read and write. Reads are
always done from corrected address space, where as writes are done
on raw address space.
Writing to corrected address space is invalid and ignored, so it
does not make sense to have this support in the driver which only
supports corrected address space regions at the moment.

Fixes: 4ab11996b4 ("nvmem: qfprom: Add Qualcomm QFPROM support.")
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200522113341.7728-1-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-11 09:23:01 +02:00

90 lines
2.2 KiB
C

/*
* Copyright (C) 2015 Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/device.h>
#include <linux/module.h>
#include <linux/io.h>
#include <linux/nvmem-provider.h>
#include <linux/platform_device.h>
static int qfprom_reg_read(void *context,
unsigned int reg, void *_val, size_t bytes)
{
void __iomem *base = context;
u8 *val = _val;
int i = 0, words = bytes;
while (words--)
*val++ = readb(base + reg + i++);
return 0;
}
static int qfprom_remove(struct platform_device *pdev)
{
struct nvmem_device *nvmem = platform_get_drvdata(pdev);
return nvmem_unregister(nvmem);
}
static struct nvmem_config econfig = {
.name = "qfprom",
.owner = THIS_MODULE,
.stride = 1,
.word_size = 1,
.reg_read = qfprom_reg_read,
};
static int qfprom_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct resource *res;
struct nvmem_device *nvmem;
void __iomem *base;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
base = devm_ioremap_resource(dev, res);
if (IS_ERR(base))
return PTR_ERR(base);
econfig.size = resource_size(res);
econfig.dev = dev;
econfig.priv = base;
nvmem = nvmem_register(&econfig);
if (IS_ERR(nvmem))
return PTR_ERR(nvmem);
platform_set_drvdata(pdev, nvmem);
return 0;
}
static const struct of_device_id qfprom_of_match[] = {
{ .compatible = "qcom,qfprom",},
{/* sentinel */},
};
MODULE_DEVICE_TABLE(of, qfprom_of_match);
static struct platform_driver qfprom_driver = {
.probe = qfprom_probe,
.remove = qfprom_remove,
.driver = {
.name = "qcom,qfprom",
.of_match_table = qfprom_of_match,
},
};
module_platform_driver(qfprom_driver);
MODULE_AUTHOR("Srinivas Kandagatla <srinivas.kandagatla@linaro.org>");
MODULE_DESCRIPTION("Qualcomm QFPROM driver");
MODULE_LICENSE("GPL v2");