Re: [PATCH v2 3/3] power: domain: Add Apple pmgr driver

Simon Glass
2021-12-28T08:39:38Z

Hi Mark,

On Thu, 23 Dec 2021 at 14:35, Mark Kettenis <kettenis@openbsd.org> wrote:
>
> This driver supports power domains for the power management
> controller found on Apple SoCs.
>
> Signed-off-by: Mark Kettenis <kettenis@openbsd.org>
> ---
> arch/arm/Kconfig | 3 +
> drivers/power/domain/Kconfig | 8 +++
> drivers/power/domain/Makefile | 1 +
> drivers/power/domain/apple-pmgr.c | 113 ++++++++++++++++++++++++++++++
> 4 files changed, 125 insertions(+)
> create mode 100644 drivers/power/domain/apple-pmgr.c

Reviewed-by: Simon Glass <sjg@chromium.org>

nits below

>
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index 59e031de04..40d3f66acb 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -938,6 +938,9 @@ config ARCH_APPLE
> select OF_BOARD
> 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 99b3f9ae71..6ef7a3b3a7 100644
> --- a/drivers/power/domain/Kconfig
> +++ b/drivers/power/domain/Kconfig
> @@ -9,6 +9,14 @@ 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 the Apple M1 power domains via
> + MMIO mapped registers.

Needs more detail here, perhaps a pointer to docs, or something about
what the driver supports.

> +
> 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 3d1e5f073c..530ae35671 100644
> --- 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
> index 0000000000..08a30c8ebf
> --- /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 100

TIMEOUT_MS ?
_US ?

> +
> +struct apple_pmgr_priv {
> + struct regmap *regmap;
> + u32 offset;

Needs comment for struct

> +};
> +
> +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);
> +}
> +
> +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) {

s/ != 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),
> +};
> --
> 2.34.1
>

Regards,
Simon