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>

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 78c6b2e..4495497 100644 (file)
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -942,6 +942,9 @@ config ARCH_APPLE
        select OF_CONTROL
        select PINCTRL
        select POSITION_INDEPENDENT
+       select POWER_DOMAIN
+       select REGMAP
+       select SYSCON
        select SYSRESET
        select SYSRESET_WATCHDOG
        select SYSRESET_WATCHDOG_AUTO

diff --git a/drivers/power/domain/Kconfig b/drivers/power/domain/Kconfig
index 99b3f9a..9aea5fc 100644 (file)
--- a/drivers/power/domain/Kconfig
+++ b/drivers/power/domain/Kconfig
@@ -9,6 +9,15 @@ config POWER_DOMAIN
          domains). This may be used to save power. This API provides the
          means to control such power management hardware.
 
+config APPLE_PMGR_POWER_DOMAIN
+       bool "Enable the Apple PMGR power domain driver"
+       depends on POWER_DOMAIN
+       default y if ARCH_APPLE
+       help
+         Enable support for manipulating power domains on Apple SoCs.
+         This driver is needed to power on parts of the SoC that have
+         not been powered on by previous boot stages.
+
 config BCM6328_POWER_DOMAIN
        bool "Enable the BCM6328 power domain driver"
        depends on POWER_DOMAIN && ARCH_BMIPS

diff --git a/drivers/power/domain/Makefile b/drivers/power/domain/Makefile
index 3d1e5f0..530ae35 100644 (file)
--- a/drivers/power/domain/Makefile
+++ b/drivers/power/domain/Makefile
@@ -4,6 +4,7 @@
 #
 
 obj-$(CONFIG_$(SPL_)POWER_DOMAIN) += power-domain-uclass.o
+obj-$(CONFIG_APPLE_PMGR_POWER_DOMAIN) += apple-pmgr.o
 obj-$(CONFIG_BCM6328_POWER_DOMAIN) += bcm6328-power-domain.o
 obj-$(CONFIG_IMX8_POWER_DOMAIN) += imx8-power-domain-legacy.o imx8-power-domain.o
 obj-$(CONFIG_IMX8M_POWER_DOMAIN) += imx8m-power-domain.o

diff --git a/drivers/power/domain/apple-pmgr.c b/drivers/power/domain/apple-pmgr.c
new file mode 100644 (file)
index 0000000..d25f136
--- /dev/null
+++ b/drivers/power/domain/apple-pmgr.c
@@ -0,0 +1,113 @@
+// 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),
+};