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

diff --git a/drivers/firmware/arm_scmi/Makefile b/drivers/firmware/arm_scmi/Makefile
index 6694d0d..11b238f 100644 (file)
--- a/drivers/firmware/arm_scmi/Makefile
+++ b/drivers/firmware/arm_scmi/Makefile
@@ -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

diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h
index 5ac0646..34bfadc 100644 (file)
--- a/drivers/firmware/arm_scmi/common.h
+++ b/drivers/firmware/arm_scmi/common.h
@@ -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);

diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index dbec767..6ef61e5 100644 (file)
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -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 */ },
 };
 

diff --git a/drivers/firmware/arm_scmi/smc.c b/drivers/firmware/arm_scmi/smc.c
new file mode 100644 (file)
index 0000000..336168e
--- /dev/null
+++ b/drivers/firmware/arm_scmi/smc.c
@@ -0,0 +1,152 @@
+// 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,
+};