Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <930ffb16-f212-0bcb-4713-2acc138c4035@ti.com>
Date:   Thu, 3 Aug 2023 10:14:03 -0500
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.13.0
Subject: Re: [PATCH V6 1/4] firmware: ti_sci: Introduce Power Management Ops
To:     Dhruva Gole <d-gole@ti.com>, Nishanth Menon <nm@ti.com>,
        Tero Kristo <kristo@kernel.org>,
        Santosh Shilimkar <ssantosh@kernel.org>
CC:     <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>, <linux-pm@vger.kernel.org>,
        Viresh Kumar <viresh.kumar@linaro.org>,
        "Praneeth Bajjuri" <praneeth@ti.com>,
        Tony Lindgren <tony@atomide.com>,
        Dave Gerlach <d-gerlach@ti.com>,
        Vibhore Vardhan <vibhore@ti.com>,
        Georgi Vlaev <g-vlaev@ti.com>,
        Roger Quadros <rogerq@kernel.org>
References: <20230803064247.503036-1-d-gole@ti.com>
 <20230803064247.503036-2-d-gole@ti.com>
Content-Language: en-US
From:   Andrew Davis <afd@ti.com>
In-Reply-To: <20230803064247.503036-2-d-gole@ti.com>
Content-Type: text/plain; charset="UTF-8"; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 8/3/23 1:42 AM, Dhruva Gole wrote:
> From: Dave Gerlach <d-gerlach@ti.com>
> 
> Introduce power management ops supported by the TISCI
> Low Power Mode API [1]. These messages are currently
> supported only on AM62x platforms.
> 
> 1) TISCI_MSG_PREPARE_SLEEP
> Prepare the SOC for entering into a low power mode and
> provide details to firmware about the state being entered.
> 
> 2) TISCI_MSG_LPM_WAKE_REASON
> Get which wake up source woke the SoC from Low Power Mode.
> The wake up source IDs will be common for all K3 platforms.
> 
> 3) TISCI_MSG_SET_IO_ISOLATION
> Control the IO isolation for Low Power Mode.
> 
> [1] https://software-dl.ti.com/tisci/esd/latest/2_tisci_msgs/pm/lpm.html
> 
> Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
> Signed-off-by: Vibhore Vardhan <vibhore@ti.com>
> [g-vlaev@ti.com: LPM_WAKE_REASON and IO_ISOLATION support]
> Signed-off-by: Georgi Vlaev <g-vlaev@ti.com>
> Tested-by: Roger Quadros <rogerq@kernel.org>
> ---
>   drivers/firmware/ti_sci.c              | 175 +++++++++++++++++++++++++
>   drivers/firmware/ti_sci.h              |  64 ++++++++-
>   include/linux/soc/ti/ti_sci_protocol.h |  44 +++++++
>   3 files changed, 282 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/firmware/ti_sci.c b/drivers/firmware/ti_sci.c
> index 26a37f47f4ca..31a71613ca54 100644
> --- a/drivers/firmware/ti_sci.c
> +++ b/drivers/firmware/ti_sci.c
> @@ -1664,6 +1664,176 @@ static int ti_sci_cmd_clk_get_freq(const struct ti_sci_handle *handle,
>   	return ret;
>   }
>   
> +/**
> + * ti_sci_cmd_prepare_sleep() - Prepare system for system suspend
> + * @handle:		pointer to TI SCI handle
> + * @mode:		Device identifier
> + * @ctx_lo:		Low part of address for context save
> + * @ctx_hi:		High part of address for context save
> + * @debug_flags:	Debug flags to pass to firmware
> + *
> + * Return: 0 if all went well, else returns appropriate error value.
> + */
> +static int ti_sci_cmd_prepare_sleep(const struct ti_sci_handle *handle, u8 mode,
> +				    u32 ctx_lo, u32 ctx_hi, u32 debug_flags)
> +{
> +	struct ti_sci_info *info;
> +	struct ti_sci_msg_req_prepare_sleep *req;
> +	struct ti_sci_msg_hdr *resp;
> +	struct ti_sci_xfer *xfer;
> +	struct device *dev;
> +	int ret = 0;
> +
> +	if (IS_ERR(handle))
> +		return PTR_ERR(handle);
> +	if (!handle)
> +		return -EINVAL;
> +
> +	info = handle_to_ti_sci_info(handle);
> +	dev = info->dev;
> +
> +	xfer = ti_sci_get_one_xfer(info, TI_SCI_MSG_PREPARE_SLEEP,
> +				   TI_SCI_FLAG_REQ_ACK_ON_PROCESSED,
> +				   sizeof(*req), sizeof(*resp));
> +	if (IS_ERR(xfer)) {
> +		ret = PTR_ERR(xfer);
> +		dev_err(dev, "Message alloc failed(%d)\n", ret);
> +		return ret;
> +	}
> +
> +	req = (struct ti_sci_msg_req_prepare_sleep *)xfer->xfer_buf;
> +	req->mode = mode;
> +	req->ctx_lo = ctx_lo;
> +	req->ctx_hi = ctx_hi;
> +	req->debug_flags = debug_flags;
> +
> +	ret = ti_sci_do_xfer(info, xfer);
> +	if (ret) {
> +		dev_err(dev, "Mbox send fail %d\n", ret);
> +		goto fail;
> +	}
> +
> +	resp = (struct ti_sci_msg_hdr *)xfer->xfer_buf;
> +
> +	ret = ti_sci_is_response_ack(resp) ? 0 : -ENODEV;
> +
> +fail:
> +	ti_sci_put_one_xfer(&info->minfo, xfer);
> +
> +	return ret;
> +}
> +
> +/**
> + * ti_sci_msg_cmd_lpm_wake_reason() - Get the wakeup source from LPM
> + * @handle:		Pointer to TI SCI handle
> + * @source:		The wakeup source that woke the SoC from LPM
> + * @timestamp:		Timestamp of the wakeup event
> + *
> + * Return: 0 if all went well, else returns appropriate error value.
> + */
> +static int ti_sci_msg_cmd_lpm_wake_reason(const struct ti_sci_handle *handle,
> +					  u32 *source, u64 *timestamp)
> +{
> +	struct ti_sci_info *info;
> +	struct ti_sci_xfer *xfer;
> +	struct ti_sci_msg_resp_lpm_wake_reason *resp;
> +	struct device *dev;
> +	int ret = 0;
> +
> +	if (IS_ERR(handle))
> +		return PTR_ERR(handle);
> +	if (!handle)
> +		return -EINVAL;
> +
> +	info = handle_to_ti_sci_info(handle);
> +	dev = info->dev;
> +
> +	xfer = ti_sci_get_one_xfer(info, TI_SCI_MSG_LPM_WAKE_REASON,
> +				   TI_SCI_FLAG_REQ_ACK_ON_PROCESSED,
> +				   sizeof(struct ti_sci_msg_hdr),
> +				   sizeof(*resp));
> +	if (IS_ERR(xfer)) {
> +		ret = PTR_ERR(xfer);
> +		dev_err(dev, "Message alloc failed(%d)\n", ret);
> +		return ret;
> +	}
> +
> +	ret = ti_sci_do_xfer(info, xfer);
> +	if (ret) {
> +		dev_err(dev, "Mbox send fail %d\n", ret);
> +		goto fail;
> +	}
> +
> +	resp = (struct ti_sci_msg_resp_lpm_wake_reason *)xfer->xfer_buf;
> +
> +	if (!ti_sci_is_response_ack(resp)) {
> +		ret = -ENODEV;
> +		goto fail;
> +	}
> +
> +	if (source)
> +		*source = resp->wake_source;
> +	if (timestamp)
> +		*timestamp = resp->wake_timestamp;
> +
> +fail:
> +	ti_sci_put_one_xfer(&info->minfo, xfer);
> +
> +	return ret;
> +}
> +
> +/**
> + * ti_sci_cmd_set_io_isolation() - Enable IO isolation in LPM
> + * @handle:		Pointer to TI SCI handle
> + * @state:		The desired state of the IO isolation
> + *
> + * Return: 0 if all went well, else returns appropriate error value.
> + */
> +static int ti_sci_cmd_set_io_isolation(const struct ti_sci_handle *handle,
> +				       u8 state)
> +{
> +	struct ti_sci_info *info;
> +	struct ti_sci_msg_req_set_io_isolation *req;
> +	struct ti_sci_msg_hdr *resp;
> +	struct ti_sci_xfer *xfer;
> +	struct device *dev;
> +	int ret = 0;
> +
> +	if (IS_ERR(handle))
> +		return PTR_ERR(handle);
> +	if (!handle)
> +		return -EINVAL;
> +
> +	info = handle_to_ti_sci_info(handle);
> +	dev = info->dev;
> +
> +	xfer = ti_sci_get_one_xfer(info, TI_SCI_MSG_SET_IO_ISOLATION,
> +				   TI_SCI_FLAG_REQ_ACK_ON_PROCESSED,
> +				   sizeof(*req), sizeof(*resp));
> +	if (IS_ERR(xfer)) {
> +		ret = PTR_ERR(xfer);
> +		dev_err(dev, "Message alloc failed(%d)\n", ret);
> +		return ret;
> +	}
> +	req = (struct ti_sci_msg_req_set_io_isolation *)xfer->xfer_buf;
> +	req->state = state;
> +
> +	ret = ti_sci_do_xfer(info, xfer);
> +	if (ret) {
> +		dev_err(dev, "Mbox send fail %d\n", ret);
> +		goto fail;
> +	}
> +
> +	resp = (struct ti_sci_msg_hdr *)xfer->xfer_buf;
> +
> +	ret = ti_sci_is_response_ack(resp) ? 0 : -ENODEV;
> +
> +fail:
> +	ti_sci_put_one_xfer(&info->minfo, xfer);
> +
> +	return ret;
> +}
> +
>   static int ti_sci_cmd_core_reboot(const struct ti_sci_handle *handle)
>   {
>   	struct ti_sci_info *info;
> @@ -2806,6 +2976,7 @@ static void ti_sci_setup_ops(struct ti_sci_info *info)
>   	struct ti_sci_core_ops *core_ops = &ops->core_ops;
>   	struct ti_sci_dev_ops *dops = &ops->dev_ops;
>   	struct ti_sci_clk_ops *cops = &ops->clk_ops;
> +	struct ti_sci_pm_ops *pmops = &ops->pm_ops;
>   	struct ti_sci_rm_core_ops *rm_core_ops = &ops->rm_core_ops;
>   	struct ti_sci_rm_irq_ops *iops = &ops->rm_irq_ops;
>   	struct ti_sci_rm_ringacc_ops *rops = &ops->rm_ring_ops;
> @@ -2845,6 +3016,10 @@ static void ti_sci_setup_ops(struct ti_sci_info *info)
>   	cops->set_freq = ti_sci_cmd_clk_set_freq;
>   	cops->get_freq = ti_sci_cmd_clk_get_freq;
>   
> +	pmops->prepare_sleep = ti_sci_cmd_prepare_sleep;
> +	pmops->lpm_wake_reason = ti_sci_msg_cmd_lpm_wake_reason;
> +	pmops->set_io_isolation = ti_sci_cmd_set_io_isolation;
> +
>   	rm_core_ops->get_range = ti_sci_cmd_get_resource_range;
>   	rm_core_ops->get_range_from_shost =
>   				ti_sci_cmd_get_resource_range_from_shost;
> diff --git a/drivers/firmware/ti_sci.h b/drivers/firmware/ti_sci.h
> index ef3a8214d002..e4bfe146c43d 100644
> --- a/drivers/firmware/ti_sci.h
> +++ b/drivers/firmware/ti_sci.h
> @@ -6,7 +6,7 @@
>    * The system works in a message response protocol
>    * See: http://processors.wiki.ti.com/index.php/TISCI for details
>    *
> - * Copyright (C)  2015-2016 Texas Instruments Incorporated - https://www.ti.com/
> + * Copyright (C)  2015-2022 Texas Instruments Incorporated - https://www.ti.com/
>    */
>   
>   #ifndef __TI_SCI_H
> @@ -35,6 +35,11 @@
>   #define TI_SCI_MSG_QUERY_CLOCK_FREQ	0x010d
>   #define TI_SCI_MSG_GET_CLOCK_FREQ	0x010e
>   
> +/* Low Power Mode Requests */
> +#define TI_SCI_MSG_PREPARE_SLEEP       0x0300
> +#define TI_SCI_MSG_LPM_WAKE_REASON	0x0306
> +#define TI_SCI_MSG_SET_IO_ISOLATION	0x0307
> +
>   /* Resource Management Requests */
>   #define TI_SCI_MSG_GET_RESOURCE_RANGE	0x1500
>   
> @@ -545,6 +550,63 @@ struct ti_sci_msg_resp_get_clock_freq {
>   	u64 freq_hz;
>   } __packed;
>   
> +#define TISCI_MSG_VALUE_SLEEP_MODE_DEEP_SLEEP				0x0
> +#define TISCI_MSG_VALUE_SLEEP_MODE_MCU_ONLY				0x1
> +#define TISCI_MSG_VALUE_SLEEP_MODE_STANDBY				0x2

Feels like excessive alignment tabs..

> +
> +/**
> + * struct tisci_msg_prepare_sleep_req - Request for TISCI_MSG_PREPARE_SLEEP.
> + *
> + * @hdr				TISCI header to provide ACK/NAK flags to the host.
> + * @mode			Low power mode to enter.
> + * @ctx_lo			Low 32-bits of physical pointer to address to use for context save.
> + * @ctx_hi			High 32-bits of physical pointer to address to use for context save.
> + * @debug_flags			Flags that can be set to halt the sequence during suspend or
> + *				resume to allow JTAG connection and debug.
> + *
> + * This message is used as the first step of entering a low power mode. It
> + * allows configurable information, including which state to enter to be
> + * easily shared from the application, as this is a non-secure message and
> + * therefore can be sent by anyone.
> + */
> +struct ti_sci_msg_req_prepare_sleep {
> +	struct ti_sci_msg_hdr	hdr;
> +	u8			mode;
> +	u32			ctx_lo;
> +	u32			ctx_hi;
> +	u32			debug_flags;
> +} __packed;
> +
> +/**
> + * struct ti_sci_msg_resp_lpm_wake_reason - Response for TI_SCI_MSG_LPM_WAKE_REASON.
> + *
> + * @hdr:		Generic header.
> + * @wake_source:	The wake up source that woke soc from LPM.
> + * @wake_timestamp:	Timestamp at which soc woke.
> + *
> + * Response to a generic message with message type TI_SCI_MSG_LPM_WAKE_REASON,
> + * used to query the wake up source from low power mode.
> + */
> +struct ti_sci_msg_resp_lpm_wake_reason {
> +	struct ti_sci_msg_hdr hdr;
> +	u32 wake_source;
> +	u64 wake_timestamp;
> +} __packed;
> +
> +/**
> + * struct tisci_msg_set_io_isolation_req - Request for TI_SCI_MSG_SET_IO_ISOLATION.
> + *
> + * @hdr:	Generic header
> + * @state:	The deseared state of the IO isolation.
> + *
> + * This message is used to enable/disable IO isolation for low power modes.
> + * Response is generic ACK / NACK message.
> + */
> +struct ti_sci_msg_req_set_io_isolation {
> +	struct ti_sci_msg_hdr hdr;
> +	u8 state;
> +} __packed;
> +
>   #define TI_SCI_IRQ_SECONDARY_HOST_INVALID	0xff
>   
>   /**
> diff --git a/include/linux/soc/ti/ti_sci_protocol.h b/include/linux/soc/ti/ti_sci_protocol.h
> index bd0d11af76c5..f2d1d74ab8fc 100644
> --- a/include/linux/soc/ti/ti_sci_protocol.h
> +++ b/include/linux/soc/ti/ti_sci_protocol.h
> @@ -195,6 +195,49 @@ struct ti_sci_clk_ops {
>   			u64 *current_freq);
>   };
>   
> +/* TISCI LPM wake up sources */
> +#define TISCI_MSG_VALUE_LPM_WAKE_SOURCE_WKUP_I2C0	0x00
> +#define TISCI_MSG_VALUE_LPM_WAKE_SOURCE_WKUP_UART0	0x10
> +#define TISCI_MSG_VALUE_LPM_WAKE_SOURCE_MCU_GPIO0	0x20
> +#define TISCI_MSG_VALUE_LPM_WAKE_SOURCE_WKUP_ICEMELTER0	0x30
> +#define TISCI_MSG_VALUE_LPM_WAKE_SOURCE_WKUP_TIMER0	0x40
> +#define TISCI_MSG_VALUE_LPM_WAKE_SOURCE_WKUP_TIMER1	0x41
> +#define TISCI_MSG_VALUE_LPM_WAKE_SOURCE_WKUP_RTC0	0x50
> +#define TISCI_MSG_VALUE_LPM_WAKE_SOURCE_RESET		0x60
> +#define TISCI_MSG_VALUE_LPM_WAKE_SOURCE_USB0		0x70
> +#define TISCI_MSG_VALUE_LPM_WAKE_SOURCE_USB1		0x71
> +#define TISCI_MSG_VALUE_LPM_WAKE_SOURCE_MAIN_IO		0x80
> +#define TISCI_MSG_VALUE_LPM_WAKE_SOURCE_MCU_IO		0x81
> +#define TISCI_MSG_VALUE_LPM_WAKE_SOURCE_CAN_IO		0x82
> +#define TISCI_MSG_VALUE_LPM_WAKE_SOURCE_INVALID		0xFF

I don't see these used in this series, do you need them? lpm_wake_reason()
doesn't seem used either and I'm not sure how you plan to use it, could
you detail that?

Andrew

> +
> +/* TISCI LPM IO isolation control values */
> +#define TISCI_MSG_VALUE_IO_ENABLE			1
> +#define TISCI_MSG_VALUE_IO_DISABLE			0
> +
> +/**
> + * struct ti_sci_pm_ops - Low Power Mode (LPM) control operations
> + * @prepare_sleep: Prepare to enter low power mode
> + *		- mode: Low power mode to enter.
> + *		- ctx_lo: Low 32-bits of physical address for context save.
> + *		- ctx_hi: High 32-bits of physical address for context save.
> + *		- ctx_lo: 'true' if frequency change is desired.
> + *		- debug_flags: JTAG control flags for debug.
> + * @lpm_wake_reason: Get the wake up source that woke the SoC from LPM
> + *		- source: The wake up source that woke soc from LPM.
> + *		- timestamp: Timestamp at which soc woke.
> + * @set_io_isolation: Enable or disable IO isolation
> + *		- state: The desired state of the IO isolation.
> + */
> +struct ti_sci_pm_ops {
> +	int (*prepare_sleep)(const struct ti_sci_handle *handle, u8 mode,
> +			     u32 ctx_lo, u32 ctx_hi, u32 flags);
> +	int (*lpm_wake_reason)(const struct ti_sci_handle *handle,
> +			       u32 *source, u64 *timestamp);
> +	int (*set_io_isolation)(const struct ti_sci_handle *handle,
> +				u8 state);
> +};
> +
>   /**
>    * struct ti_sci_resource_desc - Description of TI SCI resource instance range.
>    * @start:	Start index of the first resource range.
> @@ -539,6 +582,7 @@ struct ti_sci_ops {
>   	struct ti_sci_core_ops core_ops;
>   	struct ti_sci_dev_ops dev_ops;
>   	struct ti_sci_clk_ops clk_ops;
> +	struct ti_sci_pm_ops pm_ops;
>   	struct ti_sci_rm_core_ops rm_core_ops;
>   	struct ti_sci_rm_irq_ops rm_irq_ops;
>   	struct ti_sci_rm_ringacc_ops rm_ring_ops;