The power management controller found on Apple SoCs als provides
a way to reset all devices within a power domain. This is needed
to cleanly shutdown the NVMe controller before we hand over
control to the OS.
Signed-off-by: Mark Kettenis <kette...@openbsd.org>
---
arch/arm/Kconfig | 1 +
drivers/power/domain/apple-pmgr.c | 73 ++++++++++++++++++++++++++++++-
2 files changed, 73 insertions(+), 1 deletion(-)
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 79eec3aa06..04b4a20211 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -935,6 +935,7 @@ config ARCH_APPLE
select DM_GPIO
select DM_KEYBOARD
select DM_MAILBOX
+ select DM_RESET
select DM_SERIAL
select DM_USB
select DM_VIDEO
diff --git a/drivers/power/domain/apple-pmgr.c
b/drivers/power/domain/apple-pmgr.c
index d25f136b9d..4d06e76ff5 100644
--- a/drivers/power/domain/apple-pmgr.c
+++ b/drivers/power/domain/apple-pmgr.c
@@ -6,14 +6,22 @@
#include <common.h>
#include <asm/io.h>
#include <dm.h>
+#include <dm/device-internal.h>
#include <linux/err.h>
#include <linux/bitfield.h>
#include <power-domain-uclass.h>
+#include <reset-uclass.h>
#include <regmap.h>
#include <syscon.h>
-#define APPLE_PMGR_PS_TARGET GENMASK(3, 0)
+#define APPLE_PMGR_RESET BIT(31)
+#define APPLE_PMGR_DEV_DISABLE BIT(10)
+#define APPLE_PMGR_WAS_CLKGATED BIT(9)
+#define APPLE_PMGR_WAS_PWRGATED BIT(8)
#define APPLE_PMGR_PS_ACTUAL GENMASK(7, 4)
+#define APPLE_PMGR_PS_TARGET GENMASK(3, 0)
+
+#define APPLE_PMGR_FLAGS (APPLE_PMGR_WAS_CLKGATED |
APPLE_PMGR_WAS_PWRGATED)
#define APPLE_PMGR_PS_ACTIVE 0xf
#define APPLE_PMGR_PS_PWRGATE 0x0
@@ -25,6 +33,65 @@ struct apple_pmgr_priv {
u32 offset; /* offset within regmap for this domain */
};
+static int apple_reset_of_xlate(struct reset_ctl *reset_ctl,
+ struct ofnode_phandle_args *args)
+{
+ if (args->args_count != 0)
+ return -EINVAL;
+
+ return 0;
+}
+
+static int apple_reset_request(struct reset_ctl *reset_ctl)
+{
+ return 0;
+}
+
+static int apple_reset_free(struct reset_ctl *reset_ctl)
+{
+ return 0;
+}
+
+static int apple_reset_assert(struct reset_ctl *reset_ctl)
+{
+ struct apple_pmgr_priv *priv = dev_get_priv(reset_ctl->dev->parent);
+
+ regmap_update_bits(priv->regmap, priv->offset,
+ APPLE_PMGR_FLAGS | APPLE_PMGR_DEV_DISABLE,
+ APPLE_PMGR_DEV_DISABLE);
+ regmap_update_bits(priv->regmap, priv->offset,
+ APPLE_PMGR_FLAGS | APPLE_PMGR_RESET,
+ APPLE_PMGR_RESET);
+
+ return 0;
+}
+
+static int apple_reset_deassert(struct reset_ctl *reset_ctl)
+{
+ struct apple_pmgr_priv *priv = dev_get_priv(reset_ctl->dev->parent);
+
+ regmap_update_bits(priv->regmap, priv->offset,
+ APPLE_PMGR_FLAGS | APPLE_PMGR_RESET, 0);
+ regmap_update_bits(priv->regmap, priv->offset,
+ APPLE_PMGR_FLAGS | APPLE_PMGR_DEV_DISABLE, 0);
+
+ return 0;
+}
+
+struct reset_ops apple_reset_ops = {
+ .of_xlate = apple_reset_of_xlate,
+ .request = apple_reset_request,
+ .rfree = apple_reset_free,
+ .rst_assert = apple_reset_assert,
+ .rst_deassert = apple_reset_deassert,
+};
+
+static struct driver apple_reset_driver = {
+ .name = "apple_reset",
+ .id = UCLASS_RESET,
+ .ops = &apple_reset_ops,
+};
+
static int apple_pmgr_request(struct power_domain *power_domain)
{
return 0;
@@ -78,6 +145,7 @@ static const struct udevice_id apple_pmgr_ids[] = {
static int apple_pmgr_probe(struct udevice *dev)
{
struct apple_pmgr_priv *priv = dev_get_priv(dev);
+ struct udevice *child;
int ret;
ret = dev_power_domain_on(dev);
@@ -92,6 +160,9 @@ static int apple_pmgr_probe(struct udevice *dev)
if (ret < 0)
return ret;
+ device_bind(dev, &apple_reset_driver, "apple_reset", NULL,
+ dev_ofnode(dev), &child);
+
return 0;
}
--
2.34.1
