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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2015-2019, Arm Limited and Contributors. All rights reserved.
* Copyright (C) 2019-2020 Linaro Limited.
*/
#include <common.h>
#include <cpu_func.h>
#include <dm.h>
#include <dm/device_compat.h>
#include <errno.h>
#include <scmi_agent.h>
#include <asm/cache.h>
#include <asm/system.h>
#include <dm/ofnode.h>
#include <linux/compat.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include "smt.h"
/**
* Get shared memory configuration defined by the referred DT phandle
* Return with a errno compliant value.
*/
int scmi_dt_get_smt_buffer(struct udevice *dev, struct scmi_smt *smt)
{
int ret;
struct ofnode_phandle_args args;
struct resource resource;
fdt32_t faddr;
phys_addr_t paddr;
ret = dev_read_phandle_with_args(dev, "shmem", NULL, 0, 0, &args);
if (ret)
return ret;
ret = ofnode_read_resource(args.node, 0, &resource);
if (ret)
return ret;
faddr = cpu_to_fdt32(resource.start);
paddr = ofnode_translate_address(args.node, &faddr);
smt->size = resource_size(&resource);
if (smt->size < sizeof(struct scmi_smt_header)) {
dev_err(dev, "Shared memory buffer too small\n");
return -EINVAL;
}
smt->buf = devm_ioremap(dev, paddr, smt->size);
if (!smt->buf)
return -ENOMEM;
#ifdef CONFIG_ARM
if (dcache_status())
mmu_set_region_dcache_behaviour((uintptr_t)smt->buf,
smt->size, DCACHE_OFF);
#endif
return 0;
}
/**
* Write SCMI message @msg into a SMT shared buffer @smt.
* Return 0 on success and with a negative errno in case of error.
*/
int scmi_write_msg_to_smt(struct udevice *dev, struct scmi_smt *smt,
struct scmi_msg *msg)
{
struct scmi_smt_header *hdr = (void *)smt->buf;
if ((!msg->in_msg && msg->in_msg_sz) ||
(!msg->out_msg && msg->out_msg_sz))
return -EINVAL;
if (!(hdr->channel_status & SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE)) {
dev_dbg(dev, "Channel busy\n");
return -EBUSY;
}
if (smt->size < (sizeof(*hdr) + msg->in_msg_sz) ||
smt->size < (sizeof(*hdr) + msg->out_msg_sz)) {
dev_dbg(dev, "Buffer too small\n");
return -ETOOSMALL;
}
/* Load message in shared memory */
hdr->channel_status &= ~SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE;
hdr->length = msg->in_msg_sz + sizeof(hdr->msg_header);
hdr->msg_header = SMT_HEADER_TOKEN(0) |
SMT_HEADER_MESSAGE_TYPE(0) |
SMT_HEADER_PROTOCOL_ID(msg->protocol_id) |
SMT_HEADER_MESSAGE_ID(msg->message_id);
memcpy_toio(hdr->msg_payload, msg->in_msg, msg->in_msg_sz);
return 0;
}
/**
* Read SCMI message from a SMT shared buffer @smt and copy it into @msg.
* Return 0 on success and with a negative errno in case of error.
*/
int scmi_read_resp_from_smt(struct udevice *dev, struct scmi_smt *smt,
struct scmi_msg *msg)
{
struct scmi_smt_header *hdr = (void *)smt->buf;
if (!(hdr->channel_status & SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE)) {
dev_err(dev, "Channel unexpectedly busy\n");
return -EBUSY;
}
if (hdr->channel_status & SCMI_SHMEM_CHAN_STAT_CHANNEL_ERROR) {
dev_err(dev, "Channel error reported, reset channel\n");
return -ECOMM;
}
if (hdr->length > msg->out_msg_sz + sizeof(hdr->msg_header)) {
dev_err(dev, "Buffer to small\n");
return -ETOOSMALL;
}
/* Get the data */
msg->out_msg_sz = hdr->length - sizeof(hdr->msg_header);
memcpy_fromio(msg->out_msg, hdr->msg_payload, msg->out_msg_sz);
return 0;
}
/**
* Clear SMT flags in shared buffer to allow further message exchange
*/
void scmi_clear_smt_channel(struct scmi_smt *smt)
{
struct scmi_smt_header *hdr = (void *)smt->buf;
hdr->channel_status &= ~SCMI_SHMEM_CHAN_STAT_CHANNEL_ERROR;
}
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