linux/drivers/soc/ti/ti_sci_pm_domains.c
Lokesh Vutla de8a618f30 soc: ti: ti_sci_pm_domains: Add support for exclusive and shared access
TISCI protocol supports for enabling the device either with exclusive
permissions for the requesting host or with sharing across the hosts.
There are certain devices which are exclusive to Linux context and
there are certain devices that are shared across different host contexts.
So add support for getting this information from DT by increasing
the power-domain cells to 2.

For keeping the DT backward compatibility intact, defaulting the
device permissions to set the exclusive flag set. In this case the
power-domain-cells is 1.

Reviewed-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-09-04 20:44:35 +02:00

216 lines
5.9 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* TI SCI Generic Power Domain Driver
*
* Copyright (C) 2015-2017 Texas Instruments Incorporated - http://www.ti.com/
* J Keerthy <j-keerthy@ti.com>
* Dave Gerlach <d-gerlach@ti.com>
*/
#include <linux/err.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm_domain.h>
#include <linux/slab.h>
#include <linux/soc/ti/ti_sci_protocol.h>
#include <dt-bindings/soc/ti,sci_pm_domain.h>
/**
* struct ti_sci_genpd_dev_data: holds data needed for every device attached
* to this genpd
* @idx: index of the device that identifies it with the system
* control processor.
* @exclusive: Permissions for exclusive request or shared request of the
* device.
*/
struct ti_sci_genpd_dev_data {
int idx;
u8 exclusive;
};
/**
* struct ti_sci_pm_domain: TI specific data needed for power domain
* @ti_sci: handle to TI SCI protocol driver that provides ops to
* communicate with system control processor.
* @dev: pointer to dev for the driver for devm allocs
* @pd: generic_pm_domain for use with the genpd framework
*/
struct ti_sci_pm_domain {
const struct ti_sci_handle *ti_sci;
struct device *dev;
struct generic_pm_domain pd;
};
#define genpd_to_ti_sci_pd(gpd) container_of(gpd, struct ti_sci_pm_domain, pd)
/**
* ti_sci_dev_id(): get prepopulated ti_sci id from struct dev
* @dev: pointer to device associated with this genpd
*
* Returns device_id stored from ti,sci_id property
*/
static int ti_sci_dev_id(struct device *dev)
{
struct generic_pm_domain_data *genpd_data = dev_gpd_data(dev);
struct ti_sci_genpd_dev_data *sci_dev_data = genpd_data->data;
return sci_dev_data->idx;
}
static u8 is_ti_sci_dev_exclusive(struct device *dev)
{
struct generic_pm_domain_data *genpd_data = dev_gpd_data(dev);
struct ti_sci_genpd_dev_data *sci_dev_data = genpd_data->data;
return sci_dev_data->exclusive;
}
/**
* ti_sci_dev_to_sci_handle(): get pointer to ti_sci_handle
* @dev: pointer to device associated with this genpd
*
* Returns ti_sci_handle to be used to communicate with system
* control processor.
*/
static const struct ti_sci_handle *ti_sci_dev_to_sci_handle(struct device *dev)
{
struct generic_pm_domain *pd = pd_to_genpd(dev->pm_domain);
struct ti_sci_pm_domain *ti_sci_genpd = genpd_to_ti_sci_pd(pd);
return ti_sci_genpd->ti_sci;
}
/**
* ti_sci_dev_start(): genpd device start hook called to turn device on
* @dev: pointer to device associated with this genpd to be powered on
*/
static int ti_sci_dev_start(struct device *dev)
{
const struct ti_sci_handle *ti_sci = ti_sci_dev_to_sci_handle(dev);
int idx = ti_sci_dev_id(dev);
if (is_ti_sci_dev_exclusive(dev))
return ti_sci->ops.dev_ops.get_device_exclusive(ti_sci, idx);
else
return ti_sci->ops.dev_ops.get_device(ti_sci, idx);
}
/**
* ti_sci_dev_stop(): genpd device stop hook called to turn device off
* @dev: pointer to device associated with this genpd to be powered off
*/
static int ti_sci_dev_stop(struct device *dev)
{
const struct ti_sci_handle *ti_sci = ti_sci_dev_to_sci_handle(dev);
int idx = ti_sci_dev_id(dev);
return ti_sci->ops.dev_ops.put_device(ti_sci, idx);
}
static int ti_sci_pd_attach_dev(struct generic_pm_domain *domain,
struct device *dev)
{
struct device_node *np = dev->of_node;
struct of_phandle_args pd_args;
struct ti_sci_pm_domain *ti_sci_genpd = genpd_to_ti_sci_pd(domain);
const struct ti_sci_handle *ti_sci = ti_sci_genpd->ti_sci;
struct ti_sci_genpd_dev_data *sci_dev_data;
struct generic_pm_domain_data *genpd_data;
int idx, ret = 0;
ret = of_parse_phandle_with_args(np, "power-domains",
"#power-domain-cells", 0, &pd_args);
if (ret < 0)
return ret;
if (pd_args.args_count != 1 && pd_args.args_count != 2)
return -EINVAL;
idx = pd_args.args[0];
/*
* Check the validity of the requested idx, if the index is not valid
* the PMMC will return a NAK here and we will not allocate it.
*/
ret = ti_sci->ops.dev_ops.is_valid(ti_sci, idx);
if (ret)
return -EINVAL;
sci_dev_data = kzalloc(sizeof(*sci_dev_data), GFP_KERNEL);
if (!sci_dev_data)
return -ENOMEM;
sci_dev_data->idx = idx;
/* Enable the exclusive permissions by default */
sci_dev_data->exclusive = TI_SCI_PD_EXCLUSIVE;
if (pd_args.args_count == 2)
sci_dev_data->exclusive = pd_args.args[1] & 0x1;
genpd_data = dev_gpd_data(dev);
genpd_data->data = sci_dev_data;
return 0;
}
static void ti_sci_pd_detach_dev(struct generic_pm_domain *domain,
struct device *dev)
{
struct generic_pm_domain_data *genpd_data = dev_gpd_data(dev);
struct ti_sci_genpd_dev_data *sci_dev_data = genpd_data->data;
kfree(sci_dev_data);
genpd_data->data = NULL;
}
static const struct of_device_id ti_sci_pm_domain_matches[] = {
{ .compatible = "ti,sci-pm-domain", },
{ },
};
MODULE_DEVICE_TABLE(of, ti_sci_pm_domain_matches);
static int ti_sci_pm_domain_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
struct ti_sci_pm_domain *ti_sci_pd;
int ret;
ti_sci_pd = devm_kzalloc(dev, sizeof(*ti_sci_pd), GFP_KERNEL);
if (!ti_sci_pd)
return -ENOMEM;
ti_sci_pd->ti_sci = devm_ti_sci_get_handle(dev);
if (IS_ERR(ti_sci_pd->ti_sci))
return PTR_ERR(ti_sci_pd->ti_sci);
ti_sci_pd->dev = dev;
ti_sci_pd->pd.name = "ti_sci_pd";
ti_sci_pd->pd.attach_dev = ti_sci_pd_attach_dev;
ti_sci_pd->pd.detach_dev = ti_sci_pd_detach_dev;
ti_sci_pd->pd.dev_ops.start = ti_sci_dev_start;
ti_sci_pd->pd.dev_ops.stop = ti_sci_dev_stop;
pm_genpd_init(&ti_sci_pd->pd, NULL, true);
ret = of_genpd_add_provider_simple(np, &ti_sci_pd->pd);
return ret;
}
static struct platform_driver ti_sci_pm_domains_driver = {
.probe = ti_sci_pm_domain_probe,
.driver = {
.name = "ti_sci_pm_domains",
.of_match_table = ti_sci_pm_domain_matches,
},
};
module_platform_driver(ti_sci_pm_domains_driver);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("TI System Control Interface (SCI) Power Domain driver");
MODULE_AUTHOR("Dave Gerlach");