u-boot/drivers/power/domain/apple-pmgr.c
Mark Kettenis 97187d5e37 power: domain: Add Apple pmgr driver
This driver supports power domains for the power management
controller found on Apple SoCs.

Signed-off-by: Mark Kettenis <kettenis@openbsd.org>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2022-01-17 06:56:01 +09:00

113 lines
2.5 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2021 Mark Kettenis <kettenis@openbsd.org>
*/
#include <common.h>
#include <asm/io.h>
#include <dm.h>
#include <linux/err.h>
#include <linux/bitfield.h>
#include <power-domain-uclass.h>
#include <regmap.h>
#include <syscon.h>
#define APPLE_PMGR_PS_TARGET GENMASK(3, 0)
#define APPLE_PMGR_PS_ACTUAL GENMASK(7, 4)
#define APPLE_PMGR_PS_ACTIVE 0xf
#define APPLE_PMGR_PS_PWRGATE 0x0
#define APPLE_PMGR_PS_SET_TIMEOUT_US 100
struct apple_pmgr_priv {
struct regmap *regmap;
u32 offset; /* offset within regmap for this domain */
};
static int apple_pmgr_request(struct power_domain *power_domain)
{
return 0;
}
static int apple_pmgr_rfree(struct power_domain *power_domain)
{
return 0;
}
static int apple_pmgr_ps_set(struct power_domain *power_domain, u32 pstate)
{
struct apple_pmgr_priv *priv = dev_get_priv(power_domain->dev);
uint reg;
regmap_update_bits(priv->regmap, priv->offset, APPLE_PMGR_PS_TARGET,
FIELD_PREP(APPLE_PMGR_PS_TARGET, pstate));
return regmap_read_poll_timeout(
priv->regmap, priv->offset, reg,
(FIELD_GET(APPLE_PMGR_PS_ACTUAL, reg) == pstate), 1,
APPLE_PMGR_PS_SET_TIMEOUT_US);
}
static int apple_pmgr_on(struct power_domain *power_domain)
{
return apple_pmgr_ps_set(power_domain, APPLE_PMGR_PS_ACTIVE);
}
static int apple_pmgr_off(struct power_domain *power_domain)
{
return 0;
}
static int apple_pmgr_of_xlate(struct power_domain *power_domain,
struct ofnode_phandle_args *args)
{
if (args->args_count != 0) {
debug("Invalid args_count: %d\n", args->args_count);
return -EINVAL;
}
return 0;
}
static const struct udevice_id apple_pmgr_ids[] = {
{ .compatible = "apple,pmgr-pwrstate" },
{ /* sentinel */ }
};
static int apple_pmgr_probe(struct udevice *dev)
{
struct apple_pmgr_priv *priv = dev_get_priv(dev);
int ret;
ret = dev_power_domain_on(dev);
if (ret)
return ret;
priv->regmap = syscon_get_regmap(dev->parent);
if (IS_ERR(priv->regmap))
return PTR_ERR(priv->regmap);
ret = dev_read_u32(dev, "reg", &priv->offset);
if (ret < 0)
return ret;
return 0;
}
struct power_domain_ops apple_pmgr_ops = {
.request = apple_pmgr_request,
.rfree = apple_pmgr_rfree,
.on = apple_pmgr_on,
.off = apple_pmgr_off,
.of_xlate = apple_pmgr_of_xlate,
};
U_BOOT_DRIVER(apple_pmgr) = {
.name = "apple_pmgr",
.id = UCLASS_POWER_DOMAIN,
.of_match = apple_pmgr_ids,
.ops = &apple_pmgr_ops,
.probe = apple_pmgr_probe,
.priv_auto = sizeof(struct apple_pmgr_priv),
};