summaryrefslogtreecommitdiff
path: root/drivers/firmware/arm_scmi/smc.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/firmware/arm_scmi/smc.c')
-rw-r--r--drivers/firmware/arm_scmi/smc.c270
1 files changed, 0 insertions, 270 deletions
diff --git a/drivers/firmware/arm_scmi/smc.c b/drivers/firmware/arm_scmi/smc.c
deleted file mode 100644
index 621c37efe3ec..000000000000
--- a/drivers/firmware/arm_scmi/smc.c
+++ /dev/null
@@ -1,270 +0,0 @@
-// 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/atomic.h>
-#include <linux/device.h>
-#include <linux/err.h>
-#include <linux/interrupt.h>
-#include <linux/mutex.h>
-#include <linux/of.h>
-#include <linux/of_address.h>
-#include <linux/of_irq.h>
-#include <linux/processor.h>
-#include <linux/slab.h>
-
-#include "common.h"
-
-/*
- * The shmem address is split into 4K page and offset.
- * This is to make sure the parameters fit in 32bit arguments of the
- * smc/hvc call to keep it uniform across smc32/smc64 conventions.
- * This however limits the shmem address to 44 bit.
- *
- * These optional parameters can be used to distinguish among multiple
- * scmi instances that are using the same smc-id.
- * The page parameter is passed in r1/x1/w1 register and the offset parameter
- * is passed in r2/x2/w2 register.
- */
-
-#define SHMEM_SIZE (SZ_4K)
-#define SHMEM_SHIFT 12
-#define SHMEM_PAGE(x) (_UL((x) >> SHMEM_SHIFT))
-#define SHMEM_OFFSET(x) ((x) & (SHMEM_SIZE - 1))
-
-/**
- * struct scmi_smc - Structure representing a SCMI smc transport
- *
- * @cinfo: SCMI channel info
- * @shmem: Transmit/Receive shared memory area
- * @shmem_lock: Lock to protect access to Tx/Rx shared memory area.
- * Used when NOT operating in atomic mode.
- * @inflight: Atomic flag to protect access to Tx/Rx shared memory area.
- * Used when operating in atomic mode.
- * @func_id: smc/hvc call function id
- * @param_page: 4K page number of the shmem channel
- * @param_offset: Offset within the 4K page of the shmem channel
- */
-
-struct scmi_smc {
- struct scmi_chan_info *cinfo;
- struct scmi_shared_mem __iomem *shmem;
- /* Protect access to shmem area */
- struct mutex shmem_lock;
-#define INFLIGHT_NONE MSG_TOKEN_MAX
- atomic_t inflight;
- u32 func_id;
- u32 param_page;
- u32 param_offset;
-};
-
-static irqreturn_t smc_msg_done_isr(int irq, void *data)
-{
- struct scmi_smc *scmi_info = data;
-
- scmi_rx_callback(scmi_info->cinfo,
- shmem_read_header(scmi_info->shmem), NULL);
-
- return IRQ_HANDLED;
-}
-
-static bool smc_chan_available(struct device_node *of_node, int idx)
-{
- struct device_node *np = of_parse_phandle(of_node, "shmem", 0);
- if (!np)
- return false;
-
- of_node_put(np);
- return true;
-}
-
-static inline void smc_channel_lock_init(struct scmi_smc *scmi_info)
-{
- if (IS_ENABLED(CONFIG_ARM_SCMI_TRANSPORT_SMC_ATOMIC_ENABLE))
- atomic_set(&scmi_info->inflight, INFLIGHT_NONE);
- else
- mutex_init(&scmi_info->shmem_lock);
-}
-
-static bool smc_xfer_inflight(struct scmi_xfer *xfer, atomic_t *inflight)
-{
- int ret;
-
- ret = atomic_cmpxchg(inflight, INFLIGHT_NONE, xfer->hdr.seq);
-
- return ret == INFLIGHT_NONE;
-}
-
-static inline void
-smc_channel_lock_acquire(struct scmi_smc *scmi_info,
- struct scmi_xfer *xfer __maybe_unused)
-{
- if (IS_ENABLED(CONFIG_ARM_SCMI_TRANSPORT_SMC_ATOMIC_ENABLE))
- spin_until_cond(smc_xfer_inflight(xfer, &scmi_info->inflight));
- else
- mutex_lock(&scmi_info->shmem_lock);
-}
-
-static inline void smc_channel_lock_release(struct scmi_smc *scmi_info)
-{
- if (IS_ENABLED(CONFIG_ARM_SCMI_TRANSPORT_SMC_ATOMIC_ENABLE))
- atomic_set(&scmi_info->inflight, INFLIGHT_NONE);
- else
- mutex_unlock(&scmi_info->shmem_lock);
-}
-
-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, irq;
-
- 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 (!of_device_is_compatible(np, "arm,scmi-shmem"))
- return -ENXIO;
-
- 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;
-
- if (of_device_is_compatible(dev->of_node, "arm,scmi-smc-param")) {
- scmi_info->param_page = SHMEM_PAGE(res.start);
- scmi_info->param_offset = SHMEM_OFFSET(res.start);
- }
- /*
- * If there is an interrupt named "a2p", then the service and
- * completion of a message is signaled by an interrupt rather than by
- * the return of the SMC call.
- */
- irq = of_irq_get_byname(cdev->of_node, "a2p");
- if (irq > 0) {
- ret = devm_request_irq(dev, irq, smc_msg_done_isr,
- IRQF_NO_SUSPEND,
- dev_name(dev), scmi_info);
- if (ret) {
- dev_err(dev, "failed to setup SCMI smc irq\n");
- return ret;
- }
- } else {
- cinfo->no_completion_irq = true;
- }
-
- scmi_info->func_id = func_id;
- scmi_info->cinfo = cinfo;
- smc_channel_lock_init(scmi_info);
- 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;
-
- 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;
- unsigned long page = scmi_info->param_page;
- unsigned long offset = scmi_info->param_offset;
-
- /*
- * Channel will be released only once response has been
- * surely fully retrieved, so after .mark_txdone()
- */
- smc_channel_lock_acquire(scmi_info, xfer);
-
- shmem_tx_prepare(scmi_info->shmem, xfer, cinfo);
-
- arm_smccc_1_1_invoke(scmi_info->func_id, page, offset, 0, 0, 0, 0, 0,
- &res);
-
- /* Only SMCCC_RET_NOT_SUPPORTED is valid error code */
- if (res.a0) {
- smc_channel_lock_release(scmi_info);
- return -EOPNOTSUPP;
- }
-
- return 0;
-}
-
-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 void smc_mark_txdone(struct scmi_chan_info *cinfo, int ret,
- struct scmi_xfer *__unused)
-{
- struct scmi_smc *scmi_info = cinfo->transport_info;
-
- smc_channel_lock_release(scmi_info);
-}
-
-static const 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,
-};
-
-const struct scmi_desc scmi_smc_desc = {
- .ops = &scmi_smc_ops,
- .max_rx_timeout_ms = 30,
- .max_msg = 20,
- .max_msg_size = 128,
- /*
- * Setting .sync_cmds_atomic_replies to true for SMC assumes that,
- * once the SMC instruction has completed successfully, the issued
- * SCMI command would have been already fully processed by the SCMI
- * platform firmware and so any possible response value expected
- * for the issued command will be immmediately ready to be fetched
- * from the shared memory area.
- */
- .sync_cmds_completed_on_ret = true,
- .atomic_enabled = IS_ENABLED(CONFIG_ARM_SCMI_TRANSPORT_SMC_ATOMIC_ENABLE),
-};