linuxdebug/drivers/memory/pl353-smc.c

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2024-07-16 15:50:57 +02:00
// SPDX-License-Identifier: GPL-2.0
/*
* ARM PL353 SMC driver
*
* Copyright (C) 2012 - 2018 Xilinx, Inc
* Author: Punnaiah Choudary Kalluri <punnaiah@xilinx.com>
* Author: Naga Sureshkumar Relli <nagasure@xilinx.com>
*/
#include <linux/clk.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/amba/bus.h>
/**
* struct pl353_smc_data - Private smc driver structure
* @memclk: Pointer to the peripheral clock
* @aclk: Pointer to the AXI peripheral clock
*/
struct pl353_smc_data {
struct clk *memclk;
struct clk *aclk;
};
static int __maybe_unused pl353_smc_suspend(struct device *dev)
{
struct pl353_smc_data *pl353_smc = dev_get_drvdata(dev);
clk_disable(pl353_smc->memclk);
clk_disable(pl353_smc->aclk);
return 0;
}
static int __maybe_unused pl353_smc_resume(struct device *dev)
{
struct pl353_smc_data *pl353_smc = dev_get_drvdata(dev);
int ret;
ret = clk_enable(pl353_smc->aclk);
if (ret) {
dev_err(dev, "Cannot enable axi domain clock.\n");
return ret;
}
ret = clk_enable(pl353_smc->memclk);
if (ret) {
dev_err(dev, "Cannot enable memory clock.\n");
clk_disable(pl353_smc->aclk);
return ret;
}
return ret;
}
static SIMPLE_DEV_PM_OPS(pl353_smc_dev_pm_ops, pl353_smc_suspend,
pl353_smc_resume);
static const struct of_device_id pl353_smc_supported_children[] = {
{
.compatible = "cfi-flash"
},
{
.compatible = "arm,pl353-nand-r2p1",
},
{}
};
static int pl353_smc_probe(struct amba_device *adev, const struct amba_id *id)
{
struct device_node *of_node = adev->dev.of_node;
const struct of_device_id *match = NULL;
struct pl353_smc_data *pl353_smc;
struct device_node *child;
int err;
pl353_smc = devm_kzalloc(&adev->dev, sizeof(*pl353_smc), GFP_KERNEL);
if (!pl353_smc)
return -ENOMEM;
pl353_smc->aclk = devm_clk_get(&adev->dev, "apb_pclk");
if (IS_ERR(pl353_smc->aclk)) {
dev_err(&adev->dev, "aclk clock not found.\n");
return PTR_ERR(pl353_smc->aclk);
}
pl353_smc->memclk = devm_clk_get(&adev->dev, "memclk");
if (IS_ERR(pl353_smc->memclk)) {
dev_err(&adev->dev, "memclk clock not found.\n");
return PTR_ERR(pl353_smc->memclk);
}
err = clk_prepare_enable(pl353_smc->aclk);
if (err) {
dev_err(&adev->dev, "Unable to enable AXI clock.\n");
return err;
}
err = clk_prepare_enable(pl353_smc->memclk);
if (err) {
dev_err(&adev->dev, "Unable to enable memory clock.\n");
goto disable_axi_clk;
}
amba_set_drvdata(adev, pl353_smc);
/* Find compatible children. Only a single child is supported */
for_each_available_child_of_node(of_node, child) {
match = of_match_node(pl353_smc_supported_children, child);
if (!match) {
dev_warn(&adev->dev, "unsupported child node\n");
continue;
}
break;
}
if (!match) {
err = -ENODEV;
dev_err(&adev->dev, "no matching children\n");
goto disable_mem_clk;
}
of_platform_device_create(child, NULL, &adev->dev);
of_node_put(child);
return 0;
disable_mem_clk:
clk_disable_unprepare(pl353_smc->memclk);
disable_axi_clk:
clk_disable_unprepare(pl353_smc->aclk);
return err;
}
static void pl353_smc_remove(struct amba_device *adev)
{
struct pl353_smc_data *pl353_smc = amba_get_drvdata(adev);
clk_disable_unprepare(pl353_smc->memclk);
clk_disable_unprepare(pl353_smc->aclk);
}
static const struct amba_id pl353_ids[] = {
{
.id = 0x00041353,
.mask = 0x000fffff,
},
{ 0, 0 },
};
MODULE_DEVICE_TABLE(amba, pl353_ids);
static struct amba_driver pl353_smc_driver = {
.drv = {
.owner = THIS_MODULE,
.name = "pl353-smc",
.pm = &pl353_smc_dev_pm_ops,
},
.id_table = pl353_ids,
.probe = pl353_smc_probe,
.remove = pl353_smc_remove,
};
module_amba_driver(pl353_smc_driver);
MODULE_AUTHOR("Xilinx, Inc.");
MODULE_DESCRIPTION("ARM PL353 SMC Driver");
MODULE_LICENSE("GPL");