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/* (C) 2015 Pengutronix, Alexander Aring <aar@pengutronix.de>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Authors:
* Alexander Aring <aar@pengutronix.de>
* Eric Anholt <eric@anholt.net>
*/
#include <linux/module.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/pm_domain.h>
#include <dt-bindings/power/raspberrypi-power.h>
#include <soc/bcm2835/raspberrypi-firmware.h>
/*
* Firmware indices for the old power domains interface. Only a few
* of them were actually implemented.
*/
#define RPI_OLD_POWER_DOMAIN_USB 3
#define RPI_OLD_POWER_DOMAIN_V3D 10
struct rpi_power_domain {
u32 domain;
bool enabled;
bool old_interface;
struct generic_pm_domain base;
struct rpi_firmware *fw;
};
struct rpi_power_domains {
bool has_new_interface;
struct genpd_onecell_data xlate;
struct rpi_firmware *fw;
struct rpi_power_domain domains[RPI_POWER_DOMAIN_COUNT];
};
/*
* Packet definition used by RPI_FIRMWARE_SET_POWER_STATE and
* RPI_FIRMWARE_SET_DOMAIN_STATE
*/
struct rpi_power_domain_packet {
u32 domain;
u32 on;
};
/*
* Asks the firmware to enable or disable power on a specific power
* domain.
*/
static int rpi_firmware_set_power(struct rpi_power_domain *rpi_domain, bool on)
{
struct rpi_power_domain_packet packet;
packet.domain = rpi_domain->domain;
packet.on = on;
return rpi_firmware_property(rpi_domain->fw,
rpi_domain->old_interface ?
RPI_FIRMWARE_SET_POWER_STATE :
RPI_FIRMWARE_SET_DOMAIN_STATE,
&packet, sizeof(packet));
}
static int rpi_domain_off(struct generic_pm_domain *domain)
{
struct rpi_power_domain *rpi_domain =
container_of(domain, struct rpi_power_domain, base);
return rpi_firmware_set_power(rpi_domain, false);
}
static int rpi_domain_on(struct generic_pm_domain *domain)
{
struct rpi_power_domain *rpi_domain =
container_of(domain, struct rpi_power_domain, base);
return rpi_firmware_set_power(rpi_domain, true);
}
static void rpi_common_init_power_domain(struct rpi_power_domains *rpi_domains,
int xlate_index, const char *name)
{
struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index];
dom->fw = rpi_domains->fw;
dom->base.name = name;
dom->base.power_on = rpi_domain_on;
dom->base.power_off = rpi_domain_off;
/*
* Treat all power domains as off at boot.
*
* The firmware itself may be keeping some domains on, but
* from Linux's perspective all we control is the refcounts
* that we give to the firmware, and we can't ask the firmware
* to turn off something that we haven't ourselves turned on.
*/
pm_genpd_init(&dom->base, NULL, true);
rpi_domains->xlate.domains[xlate_index] = &dom->base;
}
static void rpi_init_power_domain(struct rpi_power_domains *rpi_domains,
int xlate_index, const char *name)
{
struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index];
if (!rpi_domains->has_new_interface)
return;
/* The DT binding index is the firmware's domain index minus one. */
dom->domain = xlate_index + 1;
rpi_common_init_power_domain(rpi_domains, xlate_index, name);
}
static void rpi_init_old_power_domain(struct rpi_power_domains *rpi_domains,
int xlate_index, int domain,
const char *name)
{
struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index];
dom->old_interface = true;
dom->domain = domain;
rpi_common_init_power_domain(rpi_domains, xlate_index, name);
}
/*
* Detects whether the firmware supports the new power domains interface.
*
* The firmware doesn't actually return an error on an unknown tag,
* and just skips over it, so we do the detection by putting an
* unexpected value in the return field and checking if it was
* unchanged.
*/
static bool
rpi_has_new_domain_support(struct rpi_power_domains *rpi_domains)
{
struct rpi_power_domain_packet packet;
int ret;
packet.domain = RPI_POWER_DOMAIN_ARM;
packet.on = ~0;
ret = rpi_firmware_property(rpi_domains->fw,
RPI_FIRMWARE_GET_DOMAIN_STATE,
&packet, sizeof(packet));
return ret == 0 && packet.on != ~0;
}
static int rpi_power_probe(struct platform_device *pdev)
{
struct device_node *fw_np;
struct device *dev = &pdev->dev;
struct rpi_power_domains *rpi_domains;
rpi_domains = devm_kzalloc(dev, sizeof(*rpi_domains), GFP_KERNEL);
if (!rpi_domains)
return -ENOMEM;
rpi_domains->xlate.domains =
devm_kcalloc(dev,
RPI_POWER_DOMAIN_COUNT,
sizeof(*rpi_domains->xlate.domains),
GFP_KERNEL);
if (!rpi_domains->xlate.domains)
return -ENOMEM;
rpi_domains->xlate.num_domains = RPI_POWER_DOMAIN_COUNT;
fw_np = of_parse_phandle(pdev->dev.of_node, "firmware", 0);
if (!fw_np) {
dev_err(&pdev->dev, "no firmware node\n");
return -ENODEV;
}
rpi_domains->fw = rpi_firmware_get(fw_np);
of_node_put(fw_np);
if (!rpi_domains->fw)
return -EPROBE_DEFER;
rpi_domains->has_new_interface =
rpi_has_new_domain_support(rpi_domains);
rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C0, "I2C0");
rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C1, "I2C1");
rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C2, "I2C2");
rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VIDEO_SCALER,
"VIDEO_SCALER");
rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VPU1, "VPU1");
rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_HDMI, "HDMI");
/*
* Use the old firmware interface for USB power, so that we
* can turn it on even if the firmware hasn't been updated.
*/
rpi_init_old_power_domain(rpi_domains, RPI_POWER_DOMAIN_USB,
RPI_OLD_POWER_DOMAIN_USB, "USB");
rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VEC, "VEC");
rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_JPEG, "JPEG");
rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_H264, "H264");
rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_V3D, "V3D");
rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_ISP, "ISP");
rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_UNICAM0, "UNICAM0");
rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_UNICAM1, "UNICAM1");
rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CCP2RX, "CCP2RX");
rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CSI2, "CSI2");
rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CPI, "CPI");
rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_DSI0, "DSI0");
rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_DSI1, "DSI1");
rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_TRANSPOSER,
"TRANSPOSER");
rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CCP2TX, "CCP2TX");
rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CDP, "CDP");
rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_ARM, "ARM");
of_genpd_add_provider_onecell(dev->of_node, &rpi_domains->xlate);
platform_set_drvdata(pdev, rpi_domains);
return 0;
}
static const struct of_device_id rpi_power_of_match[] = {
{ .compatible = "raspberrypi,bcm2835-power", },
{},
};
MODULE_DEVICE_TABLE(of, rpi_power_of_match);
static struct platform_driver rpi_power_driver = {
.driver = {
.name = "raspberrypi-power",
.of_match_table = rpi_power_of_match,
},
.probe = rpi_power_probe,
};
builtin_platform_driver(rpi_power_driver);
MODULE_AUTHOR("Alexander Aring <aar@pengutronix.de>");
MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
MODULE_DESCRIPTION("Raspberry Pi power domain driver");
MODULE_LICENSE("GPL v2");
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