Commit 1dc65580 authored by Peng Fan's avatar Peng Fan Committed by Sudeep Holla
Browse files

firmware: arm_scmi: Add smc/hvc transport 

Use the value of "arm,smc-id" property from the device tree as the first
argument for SMCCC call leaving all the other arguments as zero for now.

There is no Rx, only Tx because of smc/hvc not support Rx.

Link: https://lore.kernel.org/r/1583673879-20714-3-git-send-email-peng.fan@nxp.com


Signed-off-by: default avatarPeng Fan <peng.fan@nxp.com>
[sudeep.holla: reworded commit log/subject and fixed !HAVE_ARM_SMCCC build]
Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
parent b953dcea

drivers/firmware/arm_scmi/Makefile

+3 −1
Original line number Diff line number Diff line
@@ -2,6 +2,8 @@ 
obj-y	= scmi-bus.o scmi-driver.o scmi-protocols.o scmi-transport.o

scmi-bus-y = bus.o

scmi-driver-y = driver.o

scmi-transport-y = mailbox.o shmem.o

scmi-transport-y = shmem.o

scmi-transport-$(CONFIG_MAILBOX) += mailbox.o

scmi-transport-$(CONFIG_HAVE_ARM_SMCCC) += smc.o

scmi-protocols-y = base.o clock.o perf.o power.o reset.o sensors.o

obj-$(CONFIG_ARM_SCMI_POWER_DOMAIN) += scmi_pm_domain.o

drivers/firmware/arm_scmi/common.h

+3 −0
Original line number Diff line number Diff line
@@ -210,6 +210,9 @@ struct scmi_desc { 
};



extern const struct scmi_desc scmi_mailbox_desc;

#ifdef CONFIG_HAVE_ARM_SMCCC

extern const struct scmi_desc scmi_smc_desc;

#endif



void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr);

void scmi_free_channel(struct scmi_chan_info *cinfo, struct idr *idr, int id);

drivers/firmware/arm_scmi/driver.c

+3 −0
Original line number Diff line number Diff line
@@ -827,6 +827,9 @@ ATTRIBUTE_GROUPS(versions); 
/* Each compatible listed below must have descriptor associated with it */

static const struct of_device_id scmi_of_match[] = {

	{ .compatible = "arm,scmi", .data = &scmi_mailbox_desc },

#ifdef CONFIG_HAVE_ARM_SMCCC

	{ .compatible = "arm,scmi-smc", .data = &scmi_smc_desc},

#endif

	{ /* Sentinel */ },

};

drivers/firmware/arm_scmi/smc.c

0 → 100644
+152 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/*

 * System Control and Management Interface (SCMI) Message SMC/HVC

 * Transport driver

 *

 * Copyright 2020 NXP

 */



#include <linux/arm-smccc.h>

#include <linux/device.h>

#include <linux/err.h>

#include <linux/mutex.h>

#include <linux/of.h>

#include <linux/of_address.h>

#include <linux/slab.h>



#include "common.h"



/**

 * struct scmi_smc - Structure representing a SCMI smc transport

 *

 * @cinfo: SCMI channel info

 * @shmem: Transmit/Receive shared memory area

 * @func_id: smc/hvc call function id

 */



struct scmi_smc {

	struct scmi_chan_info *cinfo;

	struct scmi_shared_mem __iomem *shmem;

	u32 func_id;

};



static DEFINE_MUTEX(smc_mutex);



static bool smc_chan_available(struct device *dev, int idx)

{

	return true;

}



static int smc_chan_setup(struct scmi_chan_info *cinfo, struct device *dev,

			  bool tx)

{

	struct device *cdev = cinfo->dev;

	struct scmi_smc *scmi_info;

	resource_size_t size;

	struct resource res;

	struct device_node *np;

	u32 func_id;

	int ret;



	if (!tx)

		return -ENODEV;



	scmi_info = devm_kzalloc(dev, sizeof(*scmi_info), GFP_KERNEL);

	if (!scmi_info)

		return -ENOMEM;



	np = of_parse_phandle(cdev->of_node, "shmem", 0);

	if (!np)

		np = of_parse_phandle(dev->of_node, "shmem", 0);

	ret = of_address_to_resource(np, 0, &res);

	of_node_put(np);

	if (ret) {

		dev_err(cdev, "failed to get SCMI Tx shared memory\n");

		return ret;

	}



	size = resource_size(&res);

	scmi_info->shmem = devm_ioremap(dev, res.start, size);

	if (!scmi_info->shmem) {

		dev_err(dev, "failed to ioremap SCMI Tx shared memory\n");

		return -EADDRNOTAVAIL;

	}



	ret = of_property_read_u32(dev->of_node, "arm,smc-id", &func_id);

	if (ret < 0)

		return ret;



	scmi_info->func_id = func_id;

	scmi_info->cinfo = cinfo;

	cinfo->transport_info = scmi_info;



	return 0;

}



static int smc_chan_free(int id, void *p, void *data)

{

	struct scmi_chan_info *cinfo = p;

	struct scmi_smc *scmi_info = cinfo->transport_info;



	cinfo->transport_info = NULL;

	scmi_info->cinfo = NULL;



	scmi_free_channel(cinfo, data, id);



	return 0;

}



static int smc_send_message(struct scmi_chan_info *cinfo,

			    struct scmi_xfer *xfer)

{

	struct scmi_smc *scmi_info = cinfo->transport_info;

	struct arm_smccc_res res;



	mutex_lock(&smc_mutex);



	shmem_tx_prepare(scmi_info->shmem, xfer);



	arm_smccc_1_1_invoke(scmi_info->func_id, 0, 0, 0, 0, 0, 0, 0, &res);

	scmi_rx_callback(scmi_info->cinfo, shmem_read_header(scmi_info->shmem));



	mutex_unlock(&smc_mutex);



	return res.a0;

}



static void smc_mark_txdone(struct scmi_chan_info *cinfo, int ret)

{

}



static void smc_fetch_response(struct scmi_chan_info *cinfo,

			       struct scmi_xfer *xfer)

{

	struct scmi_smc *scmi_info = cinfo->transport_info;



	shmem_fetch_response(scmi_info->shmem, xfer);

}



static bool

smc_poll_done(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer)

{

	struct scmi_smc *scmi_info = cinfo->transport_info;



	return shmem_poll_done(scmi_info->shmem, xfer);

}



static struct scmi_transport_ops scmi_smc_ops = {

	.chan_available = smc_chan_available,

	.chan_setup = smc_chan_setup,

	.chan_free = smc_chan_free,

	.send_message = smc_send_message,

	.mark_txdone = smc_mark_txdone,

	.fetch_response = smc_fetch_response,

	.poll_done = smc_poll_done,

};



const struct scmi_desc scmi_smc_desc = {

	.ops = &scmi_smc_ops,

	.max_rx_timeout_ms = 30,

	.max_msg = 1,

	.max_msg_size = 128,

};

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