WSL2-Linux-Kernel/drivers/soc/fsl/rcpm.c

152 строки
3.4 KiB
C

// SPDX-License-Identifier: GPL-2.0
//
// rcpm.c - Freescale QorIQ RCPM driver
//
// Copyright 2019 NXP
//
// Author: Ran Wang <ran.wang_1@nxp.com>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/of_address.h>
#include <linux/slab.h>
#include <linux/suspend.h>
#include <linux/kernel.h>
#define RCPM_WAKEUP_CELL_MAX_SIZE 7
struct rcpm {
unsigned int wakeup_cells;
void __iomem *ippdexpcr_base;
bool little_endian;
};
/**
* rcpm_pm_prepare - performs device-level tasks associated with power
* management, such as programming related to the wakeup source control.
* @dev: Device to handle.
*
*/
static int rcpm_pm_prepare(struct device *dev)
{
int i, ret, idx;
void __iomem *base;
struct wakeup_source *ws;
struct rcpm *rcpm;
struct device_node *np = dev->of_node;
u32 value[RCPM_WAKEUP_CELL_MAX_SIZE + 1];
u32 setting[RCPM_WAKEUP_CELL_MAX_SIZE] = {0};
rcpm = dev_get_drvdata(dev);
if (!rcpm)
return -EINVAL;
base = rcpm->ippdexpcr_base;
idx = wakeup_sources_read_lock();
/* Begin with first registered wakeup source */
for_each_wakeup_source(ws) {
/* skip object which is not attached to device */
if (!ws->dev || !ws->dev->parent)
continue;
ret = device_property_read_u32_array(ws->dev->parent,
"fsl,rcpm-wakeup", value,
rcpm->wakeup_cells + 1);
/* Wakeup source should refer to current rcpm device */
if (ret || (np->phandle != value[0]))
continue;
/* Property "#fsl,rcpm-wakeup-cells" of rcpm node defines the
* number of IPPDEXPCR register cells, and "fsl,rcpm-wakeup"
* of wakeup source IP contains an integer array: <phandle to
* RCPM node, IPPDEXPCR0 setting, IPPDEXPCR1 setting,
* IPPDEXPCR2 setting, etc>.
*
* So we will go thought them to collect setting data.
*/
for (i = 0; i < rcpm->wakeup_cells; i++)
setting[i] |= value[i + 1];
}
wakeup_sources_read_unlock(idx);
/* Program all IPPDEXPCRn once */
for (i = 0; i < rcpm->wakeup_cells; i++) {
u32 tmp = setting[i];
void __iomem *address = base + i * 4;
if (!tmp)
continue;
/* We can only OR related bits */
if (rcpm->little_endian) {
tmp |= ioread32(address);
iowrite32(tmp, address);
} else {
tmp |= ioread32be(address);
iowrite32be(tmp, address);
}
}
return 0;
}
static const struct dev_pm_ops rcpm_pm_ops = {
.prepare = rcpm_pm_prepare,
};
static int rcpm_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct resource *r;
struct rcpm *rcpm;
int ret;
rcpm = devm_kzalloc(dev, sizeof(*rcpm), GFP_KERNEL);
if (!rcpm)
return -ENOMEM;
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!r)
return -ENODEV;
rcpm->ippdexpcr_base = devm_ioremap_resource(&pdev->dev, r);
if (IS_ERR(rcpm->ippdexpcr_base)) {
ret = PTR_ERR(rcpm->ippdexpcr_base);
return ret;
}
rcpm->little_endian = device_property_read_bool(
&pdev->dev, "little-endian");
ret = device_property_read_u32(&pdev->dev,
"#fsl,rcpm-wakeup-cells", &rcpm->wakeup_cells);
if (ret)
return ret;
dev_set_drvdata(&pdev->dev, rcpm);
return 0;
}
static const struct of_device_id rcpm_of_match[] = {
{ .compatible = "fsl,qoriq-rcpm-2.1+", },
{}
};
MODULE_DEVICE_TABLE(of, rcpm_of_match);
static struct platform_driver rcpm_driver = {
.driver = {
.name = "rcpm",
.of_match_table = rcpm_of_match,
.pm = &rcpm_pm_ops,
},
.probe = rcpm_probe,
};
module_platform_driver(rcpm_driver);