linux/drivers/mfd/bcm2835-pm.c
Eric Anholt 670c672608 soc: bcm: bcm2835-pm: Add support for power domains under a new binding.
This provides a free software alternative to raspberrypi-power.c's
firmware calls to manage power domains.  It also exposes a reset line,
where previously the vc4 driver had to try to force power off the
domain in order to trigger a reset.

Signed-off-by: Eric Anholt <eric@anholt.net>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
2019-01-09 16:55:09 +01:00

93 lines
2.2 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* PM MFD driver for Broadcom BCM2835
*
* This driver binds to the PM block and creates the MFD device for
* the WDT and power drivers.
*/
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/mfd/bcm2835-pm.h>
#include <linux/mfd/core.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/types.h>
#include <linux/watchdog.h>
static const struct mfd_cell bcm2835_pm_devs[] = {
{ .name = "bcm2835-wdt" },
};
static const struct mfd_cell bcm2835_power_devs[] = {
{ .name = "bcm2835-power" },
};
static int bcm2835_pm_probe(struct platform_device *pdev)
{
struct resource *res;
struct device *dev = &pdev->dev;
struct bcm2835_pm *pm;
int ret;
pm = devm_kzalloc(dev, sizeof(*pm), GFP_KERNEL);
if (!pm)
return -ENOMEM;
platform_set_drvdata(pdev, pm);
pm->dev = dev;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
pm->base = devm_ioremap_resource(dev, res);
if (IS_ERR(pm->base))
return PTR_ERR(pm->base);
ret = devm_mfd_add_devices(dev, -1,
bcm2835_pm_devs, ARRAY_SIZE(bcm2835_pm_devs),
NULL, 0, NULL);
if (ret)
return ret;
/* We'll use the presence of the AXI ASB regs in the
* bcm2835-pm binding as the key for whether we can reference
* the full PM register range and support power domains.
*/
res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
if (res) {
pm->asb = devm_ioremap_resource(dev, res);
if (IS_ERR(pm->asb))
return PTR_ERR(pm->asb);
ret = devm_mfd_add_devices(dev, -1,
bcm2835_power_devs,
ARRAY_SIZE(bcm2835_power_devs),
NULL, 0, NULL);
if (ret)
return ret;
}
return 0;
}
static const struct of_device_id bcm2835_pm_of_match[] = {
{ .compatible = "brcm,bcm2835-pm-wdt", },
{ .compatible = "brcm,bcm2835-pm", },
{},
};
MODULE_DEVICE_TABLE(of, bcm2835_pm_of_match);
static struct platform_driver bcm2835_pm_driver = {
.probe = bcm2835_pm_probe,
.driver = {
.name = "bcm2835-pm",
.of_match_table = bcm2835_pm_of_match,
},
};
module_platform_driver(bcm2835_pm_driver);
MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
MODULE_DESCRIPTION("Driver for Broadcom BCM2835 PM MFD");
MODULE_LICENSE("GPL");