154 lines
3.4 KiB
C
154 lines
3.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* System Control and Management Interface (SCMI) Message SMC/HVC
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* Transport driver
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*
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* Copyright 2020 NXP
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*/
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#include <linux/arm-smccc.h>
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#include <linux/device.h>
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#include <linux/err.h>
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#include <linux/mutex.h>
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#include <linux/of.h>
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#include <linux/of_address.h>
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#include <linux/slab.h>
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#include "common.h"
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/**
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* struct scmi_smc - Structure representing a SCMI smc transport
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*
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* @cinfo: SCMI channel info
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* @shmem: Transmit/Receive shared memory area
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* @func_id: smc/hvc call function id
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*/
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struct scmi_smc {
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struct scmi_chan_info *cinfo;
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struct scmi_shared_mem __iomem *shmem;
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struct mutex shmem_lock;
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u32 func_id;
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};
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static bool smc_chan_available(struct device *dev, int idx)
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{
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struct device_node *np = of_parse_phandle(dev->of_node, "shmem", 0);
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if (!np)
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return false;
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of_node_put(np);
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return true;
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}
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static int smc_chan_setup(struct scmi_chan_info *cinfo, struct device *dev,
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bool tx)
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{
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struct device *cdev = cinfo->dev;
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struct scmi_smc *scmi_info;
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resource_size_t size;
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struct resource res;
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struct device_node *np;
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u32 func_id;
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int ret;
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if (!tx)
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return -ENODEV;
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scmi_info = devm_kzalloc(dev, sizeof(*scmi_info), GFP_KERNEL);
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if (!scmi_info)
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return -ENOMEM;
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np = of_parse_phandle(cdev->of_node, "shmem", 0);
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ret = of_address_to_resource(np, 0, &res);
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of_node_put(np);
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if (ret) {
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dev_err(cdev, "failed to get SCMI Tx shared memory\n");
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return ret;
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}
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size = resource_size(&res);
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scmi_info->shmem = devm_ioremap(dev, res.start, size);
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if (!scmi_info->shmem) {
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dev_err(dev, "failed to ioremap SCMI Tx shared memory\n");
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return -EADDRNOTAVAIL;
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}
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ret = of_property_read_u32(dev->of_node, "arm,smc-id", &func_id);
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if (ret < 0)
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return ret;
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scmi_info->func_id = func_id;
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scmi_info->cinfo = cinfo;
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mutex_init(&scmi_info->shmem_lock);
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cinfo->transport_info = scmi_info;
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return 0;
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}
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static int smc_chan_free(int id, void *p, void *data)
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{
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struct scmi_chan_info *cinfo = p;
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struct scmi_smc *scmi_info = cinfo->transport_info;
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cinfo->transport_info = NULL;
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scmi_info->cinfo = NULL;
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scmi_free_channel(cinfo, data, id);
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return 0;
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}
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static int smc_send_message(struct scmi_chan_info *cinfo,
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struct scmi_xfer *xfer)
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{
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struct scmi_smc *scmi_info = cinfo->transport_info;
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struct arm_smccc_res res;
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mutex_lock(&scmi_info->shmem_lock);
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shmem_tx_prepare(scmi_info->shmem, xfer);
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arm_smccc_1_1_invoke(scmi_info->func_id, 0, 0, 0, 0, 0, 0, 0, &res);
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scmi_rx_callback(scmi_info->cinfo, shmem_read_header(scmi_info->shmem));
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mutex_unlock(&scmi_info->shmem_lock);
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/* Only SMCCC_RET_NOT_SUPPORTED is valid error code */
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if (res.a0)
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return -EOPNOTSUPP;
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return 0;
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}
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static void smc_fetch_response(struct scmi_chan_info *cinfo,
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struct scmi_xfer *xfer)
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{
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struct scmi_smc *scmi_info = cinfo->transport_info;
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shmem_fetch_response(scmi_info->shmem, xfer);
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}
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static bool
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smc_poll_done(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer)
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{
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struct scmi_smc *scmi_info = cinfo->transport_info;
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return shmem_poll_done(scmi_info->shmem, xfer);
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}
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static struct scmi_transport_ops scmi_smc_ops = {
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.chan_available = smc_chan_available,
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.chan_setup = smc_chan_setup,
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.chan_free = smc_chan_free,
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.send_message = smc_send_message,
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.fetch_response = smc_fetch_response,
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.poll_done = smc_poll_done,
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};
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const struct scmi_desc scmi_smc_desc = {
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.ops = &scmi_smc_ops,
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.max_rx_timeout_ms = 30,
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.max_msg = 1,
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.max_msg_size = 128,
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};
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