linux-stable/drivers/nvmem/meson-efuse.c
Carlo Caione 8cde3c2153 firmware: meson_sm: Rework driver as a proper platform driver
The secure monitor driver is currently a frankenstein driver which is
registered as a platform driver but its functionality goes through a
global struct accessed by the consumer drivers using exported helper
functions.

Try to tidy up the driver moving the firmware struct into the driver
data and make the consumer drivers referencing the secure-monitor using
a new property in the DT.

Currently only the nvmem driver is using this API so we can fix it in
the same commit.

Reviewed-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Carlo Caione <ccaione@baylibre.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>
2019-10-03 08:43:33 -07:00

120 lines
2.8 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;
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->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");