such useful debug counters. This can be helpful for debugging and
SCMI monitoring.
-config ARM_SCMI_HAVE_TRANSPORT
- bool
- help
- This declares whether at least one SCMI transport has been configured.
- Used to trigger a build bug when trying to build SCMI without any
- configured transport.
-
-config ARM_SCMI_HAVE_SHMEM
- bool
- help
- This declares whether a shared memory based transport for SCMI is
- available.
-
-config ARM_SCMI_HAVE_MSG
- bool
- help
- This declares whether a message passing based transport for SCMI is
- available.
-
-config ARM_SCMI_TRANSPORT_MAILBOX
- bool "SCMI transport based on Mailbox"
- depends on MAILBOX
- select ARM_SCMI_HAVE_TRANSPORT
- select ARM_SCMI_HAVE_SHMEM
- default y
- help
- Enable mailbox based transport for SCMI.
-
- If you want the ARM SCMI PROTOCOL stack to include support for a
- transport based on mailboxes, answer Y.
+source "drivers/firmware/arm_scmi/transports/Kconfig"
config ARM_SCMI_TRANSPORT_OPTEE
bool "SCMI transport based on OP-TEE service"
scmi-driver-y = driver.o notify.o
scmi-driver-$(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT) += raw_mode.o
scmi-transport-$(CONFIG_ARM_SCMI_HAVE_SHMEM) = shmem.o
-scmi-transport-$(CONFIG_ARM_SCMI_TRANSPORT_MAILBOX) += mailbox.o
scmi-transport-$(CONFIG_ARM_SCMI_TRANSPORT_SMC) += smc.o
scmi-transport-$(CONFIG_ARM_SCMI_HAVE_MSG) += msg.o
scmi-transport-$(CONFIG_ARM_SCMI_TRANSPORT_VIRTIO) += virtio.o
scmi-protocols-y += pinctrl.o
scmi-module-objs := $(scmi-driver-y) $(scmi-protocols-y) $(scmi-transport-y)
+obj-$(CONFIG_ARM_SCMI_PROTOCOL) += transports/
+
obj-$(CONFIG_ARM_SCMI_PROTOCOL) += scmi-core.o
obj-$(CONFIG_ARM_SCMI_PROTOCOL) += scmi-module.o
int scmi_xfer_raw_wait_for_message_response(struct scmi_chan_info *cinfo,
struct scmi_xfer *xfer,
unsigned int timeout_ms);
-#ifdef CONFIG_ARM_SCMI_TRANSPORT_MAILBOX
-extern const struct scmi_desc scmi_mailbox_desc;
-#endif
#ifdef CONFIG_ARM_SCMI_TRANSPORT_SMC
extern const struct scmi_desc scmi_smc_desc;
#endif
/* Each compatible listed below must have descriptor associated with it */
static const struct of_device_id scmi_of_match[] = {
-#ifdef CONFIG_ARM_SCMI_TRANSPORT_MAILBOX
- { .compatible = "arm,scmi", .data = &scmi_mailbox_desc },
-#endif
#ifdef CONFIG_ARM_SCMI_TRANSPORT_OPTEE
{ .compatible = "linaro,scmi-optee", .data = &scmi_optee_desc },
#endif
+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0
-/*
- * System Control and Management Interface (SCMI) Message Mailbox Transport
- * driver.
- *
- * Copyright (C) 2019 ARM Ltd.
- */
-
-#include <linux/err.h>
-#include <linux/device.h>
-#include <linux/mailbox_client.h>
-#include <linux/of.h>
-#include <linux/of_address.h>
-#include <linux/slab.h>
-
-#include "common.h"
-
-/**
- * struct scmi_mailbox - Structure representing a SCMI mailbox transport
- *
- * @cl: Mailbox Client
- * @chan: Transmit/Receive mailbox uni/bi-directional channel
- * @chan_receiver: Optional Receiver mailbox unidirectional channel
- * @chan_platform_receiver: Optional Platform Receiver mailbox unidirectional channel
- * @cinfo: SCMI channel info
- * @shmem: Transmit/Receive shared memory area
- */
-struct scmi_mailbox {
- struct mbox_client cl;
- struct mbox_chan *chan;
- struct mbox_chan *chan_receiver;
- struct mbox_chan *chan_platform_receiver;
- struct scmi_chan_info *cinfo;
- struct scmi_shared_mem __iomem *shmem;
-};
-
-#define client_to_scmi_mailbox(c) container_of(c, struct scmi_mailbox, cl)
-
-static void tx_prepare(struct mbox_client *cl, void *m)
-{
- struct scmi_mailbox *smbox = client_to_scmi_mailbox(cl);
-
- scmi_shmem_ops.tx_prepare(smbox->shmem, m, smbox->cinfo);
-}
-
-static void rx_callback(struct mbox_client *cl, void *m)
-{
- struct scmi_mailbox *smbox = client_to_scmi_mailbox(cl);
-
- /*
- * An A2P IRQ is NOT valid when received while the platform still has
- * the ownership of the channel, because the platform at first releases
- * the SMT channel and then sends the completion interrupt.
- *
- * This addresses a possible race condition in which a spurious IRQ from
- * a previous timed-out reply which arrived late could be wrongly
- * associated with the next pending transaction.
- */
- if (cl->knows_txdone && !scmi_shmem_ops.channel_free(smbox->shmem)) {
- dev_warn(smbox->cinfo->dev, "Ignoring spurious A2P IRQ !\n");
- scmi_bad_message_trace(smbox->cinfo,
- scmi_shmem_ops.read_header(smbox->shmem),
- MSG_MBOX_SPURIOUS);
- return;
- }
-
- scmi_rx_callback(smbox->cinfo, scmi_shmem_ops.read_header(smbox->shmem), NULL);
-}
-
-static bool mailbox_chan_available(struct device_node *of_node, int idx)
-{
- int num_mb;
-
- /*
- * Just check if bidirrectional channels are involved, and check the
- * index accordingly; proper full validation will be made later
- * in mailbox_chan_setup().
- */
- num_mb = of_count_phandle_with_args(of_node, "mboxes", "#mbox-cells");
- if (num_mb == 3 && idx == 1)
- idx = 2;
-
- return !of_parse_phandle_with_args(of_node, "mboxes",
- "#mbox-cells", idx, NULL);
-}
-
-/**
- * mailbox_chan_validate - Validate transport configuration and map channels
- *
- * @cdev: Reference to the underlying transport device carrying the
- * of_node descriptor to analyze.
- * @a2p_rx_chan: A reference to an optional unidirectional channel to use
- * for replies on the a2p channel. Set as zero if not present.
- * @p2a_chan: A reference to the optional p2a channel.
- * Set as zero if not present.
- * @p2a_rx_chan: A reference to the optional p2a completion channel.
- * Set as zero if not present.
- *
- * At first, validate the transport configuration as described in terms of
- * 'mboxes' and 'shmem', then determin which mailbox channel indexes are
- * appropriate to be use in the current configuration.
- *
- * Return: 0 on Success or error
- */
-static int mailbox_chan_validate(struct device *cdev, int *a2p_rx_chan,
- int *p2a_chan, int *p2a_rx_chan)
-{
- int num_mb, num_sh, ret = 0;
- struct device_node *np = cdev->of_node;
-
- num_mb = of_count_phandle_with_args(np, "mboxes", "#mbox-cells");
- num_sh = of_count_phandle_with_args(np, "shmem", NULL);
- dev_dbg(cdev, "Found %d mboxes and %d shmems !\n", num_mb, num_sh);
-
- /* Bail out if mboxes and shmem descriptors are inconsistent */
- if (num_mb <= 0 || num_sh <= 0 || num_sh > 2 || num_mb > 4 ||
- (num_mb == 1 && num_sh != 1) || (num_mb == 3 && num_sh != 2) ||
- (num_mb == 4 && num_sh != 2)) {
- dev_warn(cdev,
- "Invalid channel descriptor for '%s' - mbs:%d shm:%d\n",
- of_node_full_name(np), num_mb, num_sh);
- return -EINVAL;
- }
-
- /* Bail out if provided shmem descriptors do not refer distinct areas */
- if (num_sh > 1) {
- struct device_node *np_tx, *np_rx;
-
- np_tx = of_parse_phandle(np, "shmem", 0);
- np_rx = of_parse_phandle(np, "shmem", 1);
- if (!np_tx || !np_rx || np_tx == np_rx) {
- dev_warn(cdev, "Invalid shmem descriptor for '%s'\n",
- of_node_full_name(np));
- ret = -EINVAL;
- }
-
- of_node_put(np_tx);
- of_node_put(np_rx);
- }
-
- /* Calculate channels IDs to use depending on mboxes/shmem layout */
- if (!ret) {
- switch (num_mb) {
- case 1:
- *a2p_rx_chan = 0;
- *p2a_chan = 0;
- *p2a_rx_chan = 0;
- break;
- case 2:
- if (num_sh == 2) {
- *a2p_rx_chan = 0;
- *p2a_chan = 1;
- } else {
- *a2p_rx_chan = 1;
- *p2a_chan = 0;
- }
- *p2a_rx_chan = 0;
- break;
- case 3:
- *a2p_rx_chan = 1;
- *p2a_chan = 2;
- *p2a_rx_chan = 0;
- break;
- case 4:
- *a2p_rx_chan = 1;
- *p2a_chan = 2;
- *p2a_rx_chan = 3;
- break;
- }
- }
-
- return ret;
-}
-
-static int mailbox_chan_setup(struct scmi_chan_info *cinfo, struct device *dev,
- bool tx)
-{
- const char *desc = tx ? "Tx" : "Rx";
- struct device *cdev = cinfo->dev;
- struct scmi_mailbox *smbox;
- int ret, a2p_rx_chan, p2a_chan, p2a_rx_chan;
- struct mbox_client *cl;
-
- ret = mailbox_chan_validate(cdev, &a2p_rx_chan, &p2a_chan, &p2a_rx_chan);
- if (ret)
- return ret;
-
- if (!tx && !p2a_chan)
- return -ENODEV;
-
- smbox = devm_kzalloc(dev, sizeof(*smbox), GFP_KERNEL);
- if (!smbox)
- return -ENOMEM;
-
- smbox->shmem = scmi_shmem_ops.setup_iomap(cinfo, dev, tx, NULL);
- if (IS_ERR(smbox->shmem))
- return PTR_ERR(smbox->shmem);
-
- cl = &smbox->cl;
- cl->dev = cdev;
- cl->tx_prepare = tx ? tx_prepare : NULL;
- cl->rx_callback = rx_callback;
- cl->tx_block = false;
- cl->knows_txdone = tx;
-
- smbox->chan = mbox_request_channel(cl, tx ? 0 : p2a_chan);
- if (IS_ERR(smbox->chan)) {
- ret = PTR_ERR(smbox->chan);
- if (ret != -EPROBE_DEFER)
- dev_err(cdev,
- "failed to request SCMI %s mailbox\n", desc);
- return ret;
- }
-
- /* Additional unidirectional channel for TX if needed */
- if (tx && a2p_rx_chan) {
- smbox->chan_receiver = mbox_request_channel(cl, a2p_rx_chan);
- if (IS_ERR(smbox->chan_receiver)) {
- ret = PTR_ERR(smbox->chan_receiver);
- if (ret != -EPROBE_DEFER)
- dev_err(cdev, "failed to request SCMI Tx Receiver mailbox\n");
- return ret;
- }
- }
-
- if (!tx && p2a_rx_chan) {
- smbox->chan_platform_receiver = mbox_request_channel(cl, p2a_rx_chan);
- if (IS_ERR(smbox->chan_platform_receiver)) {
- ret = PTR_ERR(smbox->chan_platform_receiver);
- if (ret != -EPROBE_DEFER)
- dev_err(cdev, "failed to request SCMI P2A Receiver mailbox\n");
- return ret;
- }
- }
-
-
- cinfo->transport_info = smbox;
- smbox->cinfo = cinfo;
-
- return 0;
-}
-
-static int mailbox_chan_free(int id, void *p, void *data)
-{
- struct scmi_chan_info *cinfo = p;
- struct scmi_mailbox *smbox = cinfo->transport_info;
-
- if (smbox && !IS_ERR(smbox->chan)) {
- mbox_free_channel(smbox->chan);
- mbox_free_channel(smbox->chan_receiver);
- mbox_free_channel(smbox->chan_platform_receiver);
- cinfo->transport_info = NULL;
- smbox->chan = NULL;
- smbox->chan_receiver = NULL;
- smbox->chan_platform_receiver = NULL;
- smbox->cinfo = NULL;
- }
-
- return 0;
-}
-
-static int mailbox_send_message(struct scmi_chan_info *cinfo,
- struct scmi_xfer *xfer)
-{
- struct scmi_mailbox *smbox = cinfo->transport_info;
- int ret;
-
- ret = mbox_send_message(smbox->chan, xfer);
-
- /* mbox_send_message returns non-negative value on success, so reset */
- if (ret > 0)
- ret = 0;
-
- return ret;
-}
-
-static void mailbox_mark_txdone(struct scmi_chan_info *cinfo, int ret,
- struct scmi_xfer *__unused)
-{
- struct scmi_mailbox *smbox = cinfo->transport_info;
-
- /*
- * NOTE: we might prefer not to need the mailbox ticker to manage the
- * transfer queueing since the protocol layer queues things by itself.
- * Unfortunately, we have to kick the mailbox framework after we have
- * received our message.
- */
- mbox_client_txdone(smbox->chan, ret);
-}
-
-static void mailbox_fetch_response(struct scmi_chan_info *cinfo,
- struct scmi_xfer *xfer)
-{
- struct scmi_mailbox *smbox = cinfo->transport_info;
-
- scmi_shmem_ops.fetch_response(smbox->shmem, xfer);
-}
-
-static void mailbox_fetch_notification(struct scmi_chan_info *cinfo,
- size_t max_len, struct scmi_xfer *xfer)
-{
- struct scmi_mailbox *smbox = cinfo->transport_info;
-
- scmi_shmem_ops.fetch_notification(smbox->shmem, max_len, xfer);
-}
-
-static void mailbox_clear_channel(struct scmi_chan_info *cinfo)
-{
- struct scmi_mailbox *smbox = cinfo->transport_info;
- struct mbox_chan *intr_chan;
- int ret;
-
- scmi_shmem_ops.clear_channel(smbox->shmem);
-
- if (!scmi_shmem_ops.channel_intr_enabled(smbox->shmem))
- return;
-
- if (smbox->chan_platform_receiver)
- intr_chan = smbox->chan_platform_receiver;
- else if (smbox->chan)
- intr_chan = smbox->chan;
- else
- return;
-
- ret = mbox_send_message(intr_chan, NULL);
- /* mbox_send_message returns non-negative value on success, so reset */
- if (ret > 0)
- ret = 0;
-
- mbox_client_txdone(intr_chan, ret);
-}
-
-static bool
-mailbox_poll_done(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer)
-{
- struct scmi_mailbox *smbox = cinfo->transport_info;
-
- return scmi_shmem_ops.poll_done(smbox->shmem, xfer);
-}
-
-static const struct scmi_transport_ops scmi_mailbox_ops = {
- .chan_available = mailbox_chan_available,
- .chan_setup = mailbox_chan_setup,
- .chan_free = mailbox_chan_free,
- .send_message = mailbox_send_message,
- .mark_txdone = mailbox_mark_txdone,
- .fetch_response = mailbox_fetch_response,
- .fetch_notification = mailbox_fetch_notification,
- .clear_channel = mailbox_clear_channel,
- .poll_done = mailbox_poll_done,
-};
-
-const struct scmi_desc scmi_mailbox_desc = {
- .ops = &scmi_mailbox_ops,
- .max_rx_timeout_ms = 30, /* We may increase this if required */
- .max_msg = 20, /* Limited by MBOX_TX_QUEUE_LEN */
- .max_msg_size = 128,
-};
--- /dev/null
+# SPDX-License-Identifier: GPL-2.0-only
+menu "SCMI Transport Drivers"
+
+config ARM_SCMI_HAVE_TRANSPORT
+ bool
+ help
+ This declares whether at least one SCMI transport has been configured.
+ Used to trigger a build bug when trying to build SCMI without any
+ configured transport.
+
+config ARM_SCMI_HAVE_SHMEM
+ bool
+ help
+ This declares whether a shared memory based transport for SCMI is
+ available.
+
+config ARM_SCMI_HAVE_MSG
+ bool
+ help
+ This declares whether a message passing based transport for SCMI is
+ available.
+
+config ARM_SCMI_TRANSPORT_MAILBOX
+ tristate "SCMI transport based on Mailbox"
+ depends on MAILBOX
+ select ARM_SCMI_HAVE_TRANSPORT
+ select ARM_SCMI_HAVE_SHMEM
+ default y
+ help
+ Enable mailbox based transport for SCMI.
+
+ If you want the ARM SCMI PROTOCOL stack to include support for a
+ transport based on mailboxes, answer Y.
+ This driver can also be built as a module. If so, the module
+ will be called scmi_transport_mailbox.
+
+endmenu
--- /dev/null
+# SPDX-License-Identifier: GPL-2.0-only
+scmi_transport_mailbox-objs := mailbox.o
+obj-$(CONFIG_ARM_SCMI_TRANSPORT_MAILBOX) += scmi_transport_mailbox.o
+
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * System Control and Management Interface (SCMI) Message Mailbox Transport
+ * driver.
+ *
+ * Copyright (C) 2019-2024 ARM Ltd.
+ */
+
+#include <linux/err.h>
+#include <linux/device.h>
+#include <linux/mailbox_client.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include "../common.h"
+
+/**
+ * struct scmi_mailbox - Structure representing a SCMI mailbox transport
+ *
+ * @cl: Mailbox Client
+ * @chan: Transmit/Receive mailbox uni/bi-directional channel
+ * @chan_receiver: Optional Receiver mailbox unidirectional channel
+ * @chan_platform_receiver: Optional Platform Receiver mailbox unidirectional channel
+ * @cinfo: SCMI channel info
+ * @shmem: Transmit/Receive shared memory area
+ */
+struct scmi_mailbox {
+ struct mbox_client cl;
+ struct mbox_chan *chan;
+ struct mbox_chan *chan_receiver;
+ struct mbox_chan *chan_platform_receiver;
+ struct scmi_chan_info *cinfo;
+ struct scmi_shared_mem __iomem *shmem;
+};
+
+#define client_to_scmi_mailbox(c) container_of(c, struct scmi_mailbox, cl)
+
+static struct scmi_transport_core_operations *core;
+
+static void tx_prepare(struct mbox_client *cl, void *m)
+{
+ struct scmi_mailbox *smbox = client_to_scmi_mailbox(cl);
+
+ core->shmem->tx_prepare(smbox->shmem, m, smbox->cinfo);
+}
+
+static void rx_callback(struct mbox_client *cl, void *m)
+{
+ struct scmi_mailbox *smbox = client_to_scmi_mailbox(cl);
+
+ /*
+ * An A2P IRQ is NOT valid when received while the platform still has
+ * the ownership of the channel, because the platform at first releases
+ * the SMT channel and then sends the completion interrupt.
+ *
+ * This addresses a possible race condition in which a spurious IRQ from
+ * a previous timed-out reply which arrived late could be wrongly
+ * associated with the next pending transaction.
+ */
+ if (cl->knows_txdone &&
+ !core->shmem->channel_free(smbox->shmem)) {
+ dev_warn(smbox->cinfo->dev, "Ignoring spurious A2P IRQ !\n");
+ core->bad_message_trace(smbox->cinfo,
+ core->shmem->read_header(smbox->shmem),
+ MSG_MBOX_SPURIOUS);
+ return;
+ }
+
+ core->rx_callback(smbox->cinfo,
+ core->shmem->read_header(smbox->shmem), NULL);
+}
+
+static bool mailbox_chan_available(struct device_node *of_node, int idx)
+{
+ int num_mb;
+
+ /*
+ * Just check if bidirrectional channels are involved, and check the
+ * index accordingly; proper full validation will be made later
+ * in mailbox_chan_setup().
+ */
+ num_mb = of_count_phandle_with_args(of_node, "mboxes", "#mbox-cells");
+ if (num_mb == 3 && idx == 1)
+ idx = 2;
+
+ return !of_parse_phandle_with_args(of_node, "mboxes",
+ "#mbox-cells", idx, NULL);
+}
+
+/**
+ * mailbox_chan_validate - Validate transport configuration and map channels
+ *
+ * @cdev: Reference to the underlying transport device carrying the
+ * of_node descriptor to analyze.
+ * @a2p_rx_chan: A reference to an optional unidirectional channel to use
+ * for replies on the a2p channel. Set as zero if not present.
+ * @p2a_chan: A reference to the optional p2a channel.
+ * Set as zero if not present.
+ * @p2a_rx_chan: A reference to the optional p2a completion channel.
+ * Set as zero if not present.
+ *
+ * At first, validate the transport configuration as described in terms of
+ * 'mboxes' and 'shmem', then determin which mailbox channel indexes are
+ * appropriate to be use in the current configuration.
+ *
+ * Return: 0 on Success or error
+ */
+static int mailbox_chan_validate(struct device *cdev, int *a2p_rx_chan,
+ int *p2a_chan, int *p2a_rx_chan)
+{
+ int num_mb, num_sh, ret = 0;
+ struct device_node *np = cdev->of_node;
+
+ num_mb = of_count_phandle_with_args(np, "mboxes", "#mbox-cells");
+ num_sh = of_count_phandle_with_args(np, "shmem", NULL);
+ dev_dbg(cdev, "Found %d mboxes and %d shmems !\n", num_mb, num_sh);
+
+ /* Bail out if mboxes and shmem descriptors are inconsistent */
+ if (num_mb <= 0 || num_sh <= 0 || num_sh > 2 || num_mb > 4 ||
+ (num_mb == 1 && num_sh != 1) || (num_mb == 3 && num_sh != 2) ||
+ (num_mb == 4 && num_sh != 2)) {
+ dev_warn(cdev,
+ "Invalid channel descriptor for '%s' - mbs:%d shm:%d\n",
+ of_node_full_name(np), num_mb, num_sh);
+ return -EINVAL;
+ }
+
+ /* Bail out if provided shmem descriptors do not refer distinct areas */
+ if (num_sh > 1) {
+ struct device_node *np_tx, *np_rx;
+
+ np_tx = of_parse_phandle(np, "shmem", 0);
+ np_rx = of_parse_phandle(np, "shmem", 1);
+ if (!np_tx || !np_rx || np_tx == np_rx) {
+ dev_warn(cdev, "Invalid shmem descriptor for '%s'\n",
+ of_node_full_name(np));
+ ret = -EINVAL;
+ }
+
+ of_node_put(np_tx);
+ of_node_put(np_rx);
+ }
+
+ /* Calculate channels IDs to use depending on mboxes/shmem layout */
+ if (!ret) {
+ switch (num_mb) {
+ case 1:
+ *a2p_rx_chan = 0;
+ *p2a_chan = 0;
+ *p2a_rx_chan = 0;
+ break;
+ case 2:
+ if (num_sh == 2) {
+ *a2p_rx_chan = 0;
+ *p2a_chan = 1;
+ } else {
+ *a2p_rx_chan = 1;
+ *p2a_chan = 0;
+ }
+ *p2a_rx_chan = 0;
+ break;
+ case 3:
+ *a2p_rx_chan = 1;
+ *p2a_chan = 2;
+ *p2a_rx_chan = 0;
+ break;
+ case 4:
+ *a2p_rx_chan = 1;
+ *p2a_chan = 2;
+ *p2a_rx_chan = 3;
+ break;
+ }
+ }
+
+ return ret;
+}
+
+static int mailbox_chan_setup(struct scmi_chan_info *cinfo, struct device *dev,
+ bool tx)
+{
+ const char *desc = tx ? "Tx" : "Rx";
+ struct device *cdev = cinfo->dev;
+ struct scmi_mailbox *smbox;
+ int ret, a2p_rx_chan, p2a_chan, p2a_rx_chan;
+ struct mbox_client *cl;
+
+ ret = mailbox_chan_validate(cdev, &a2p_rx_chan, &p2a_chan, &p2a_rx_chan);
+ if (ret)
+ return ret;
+
+ if (!tx && !p2a_chan)
+ return -ENODEV;
+
+ smbox = devm_kzalloc(dev, sizeof(*smbox), GFP_KERNEL);
+ if (!smbox)
+ return -ENOMEM;
+
+ smbox->shmem = core->shmem->setup_iomap(cinfo, dev, tx, NULL);
+ if (IS_ERR(smbox->shmem))
+ return PTR_ERR(smbox->shmem);
+
+ cl = &smbox->cl;
+ cl->dev = cdev;
+ cl->tx_prepare = tx ? tx_prepare : NULL;
+ cl->rx_callback = rx_callback;
+ cl->tx_block = false;
+ cl->knows_txdone = tx;
+
+ smbox->chan = mbox_request_channel(cl, tx ? 0 : p2a_chan);
+ if (IS_ERR(smbox->chan)) {
+ ret = PTR_ERR(smbox->chan);
+ if (ret != -EPROBE_DEFER)
+ dev_err(cdev,
+ "failed to request SCMI %s mailbox\n", desc);
+ return ret;
+ }
+
+ /* Additional unidirectional channel for TX if needed */
+ if (tx && a2p_rx_chan) {
+ smbox->chan_receiver = mbox_request_channel(cl, a2p_rx_chan);
+ if (IS_ERR(smbox->chan_receiver)) {
+ ret = PTR_ERR(smbox->chan_receiver);
+ if (ret != -EPROBE_DEFER)
+ dev_err(cdev, "failed to request SCMI Tx Receiver mailbox\n");
+ return ret;
+ }
+ }
+
+ if (!tx && p2a_rx_chan) {
+ smbox->chan_platform_receiver = mbox_request_channel(cl, p2a_rx_chan);
+ if (IS_ERR(smbox->chan_platform_receiver)) {
+ ret = PTR_ERR(smbox->chan_platform_receiver);
+ if (ret != -EPROBE_DEFER)
+ dev_err(cdev, "failed to request SCMI P2A Receiver mailbox\n");
+ return ret;
+ }
+ }
+
+
+ cinfo->transport_info = smbox;
+ smbox->cinfo = cinfo;
+
+ return 0;
+}
+
+static int mailbox_chan_free(int id, void *p, void *data)
+{
+ struct scmi_chan_info *cinfo = p;
+ struct scmi_mailbox *smbox = cinfo->transport_info;
+
+ if (smbox && !IS_ERR(smbox->chan)) {
+ mbox_free_channel(smbox->chan);
+ mbox_free_channel(smbox->chan_receiver);
+ mbox_free_channel(smbox->chan_platform_receiver);
+ cinfo->transport_info = NULL;
+ smbox->chan = NULL;
+ smbox->chan_receiver = NULL;
+ smbox->chan_platform_receiver = NULL;
+ smbox->cinfo = NULL;
+ }
+
+ return 0;
+}
+
+static int mailbox_send_message(struct scmi_chan_info *cinfo,
+ struct scmi_xfer *xfer)
+{
+ struct scmi_mailbox *smbox = cinfo->transport_info;
+ int ret;
+
+ ret = mbox_send_message(smbox->chan, xfer);
+
+ /* mbox_send_message returns non-negative value on success, so reset */
+ if (ret > 0)
+ ret = 0;
+
+ return ret;
+}
+
+static void mailbox_mark_txdone(struct scmi_chan_info *cinfo, int ret,
+ struct scmi_xfer *__unused)
+{
+ struct scmi_mailbox *smbox = cinfo->transport_info;
+
+ /*
+ * NOTE: we might prefer not to need the mailbox ticker to manage the
+ * transfer queueing since the protocol layer queues things by itself.
+ * Unfortunately, we have to kick the mailbox framework after we have
+ * received our message.
+ */
+ mbox_client_txdone(smbox->chan, ret);
+}
+
+static void mailbox_fetch_response(struct scmi_chan_info *cinfo,
+ struct scmi_xfer *xfer)
+{
+ struct scmi_mailbox *smbox = cinfo->transport_info;
+
+ core->shmem->fetch_response(smbox->shmem, xfer);
+}
+
+static void mailbox_fetch_notification(struct scmi_chan_info *cinfo,
+ size_t max_len, struct scmi_xfer *xfer)
+{
+ struct scmi_mailbox *smbox = cinfo->transport_info;
+
+ core->shmem->fetch_notification(smbox->shmem, max_len, xfer);
+}
+
+static void mailbox_clear_channel(struct scmi_chan_info *cinfo)
+{
+ struct scmi_mailbox *smbox = cinfo->transport_info;
+ struct mbox_chan *intr_chan;
+ int ret;
+
+ core->shmem->clear_channel(smbox->shmem);
+
+ if (!core->shmem->channel_intr_enabled(smbox->shmem))
+ return;
+
+ if (smbox->chan_platform_receiver)
+ intr_chan = smbox->chan_platform_receiver;
+ else if (smbox->chan)
+ intr_chan = smbox->chan;
+ else
+ return;
+
+ ret = mbox_send_message(intr_chan, NULL);
+ /* mbox_send_message returns non-negative value on success, so reset */
+ if (ret > 0)
+ ret = 0;
+
+ mbox_client_txdone(intr_chan, ret);
+}
+
+static bool
+mailbox_poll_done(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer)
+{
+ struct scmi_mailbox *smbox = cinfo->transport_info;
+
+ return core->shmem->poll_done(smbox->shmem, xfer);
+}
+
+static const struct scmi_transport_ops scmi_mailbox_ops = {
+ .chan_available = mailbox_chan_available,
+ .chan_setup = mailbox_chan_setup,
+ .chan_free = mailbox_chan_free,
+ .send_message = mailbox_send_message,
+ .mark_txdone = mailbox_mark_txdone,
+ .fetch_response = mailbox_fetch_response,
+ .fetch_notification = mailbox_fetch_notification,
+ .clear_channel = mailbox_clear_channel,
+ .poll_done = mailbox_poll_done,
+};
+
+static const struct scmi_desc scmi_mailbox_desc = {
+ .ops = &scmi_mailbox_ops,
+ .max_rx_timeout_ms = 30, /* We may increase this if required */
+ .max_msg = 20, /* Limited by MBOX_TX_QUEUE_LEN */
+ .max_msg_size = 128,
+};
+
+static const struct of_device_id scmi_of_match[] = {
+ { .compatible = "arm,scmi" },
+ { /* Sentinel */ },
+};
+
+DEFINE_SCMI_TRANSPORT_DRIVER(scmi_mailbox, scmi_mailbox_driver,
+ scmi_mailbox_desc, scmi_of_match, core);
+module_platform_driver(scmi_mailbox_driver);
+
+MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
+MODULE_DESCRIPTION("SCMI Mailbox Transport driver");
+MODULE_LICENSE("GPL");
projects / linux-block.git / commitdiff