@@ -254,4 +254,16 @@ config QCOM_IPCC
acts as an interrupt controller for receiving interrupts from clients.
Say Y here if you want to build this driver.
+config BRCMSTB_MBOX
+ tristate "Broadcom STB Mailbox"
+ depends on ARM64 || ARM
+ depends on ARM_SCMI_PROTOCOL && ARCH_BRCMSTB
+ default ARM_SCMI_PROTOCOL && ARCH_BRCMSTB
+ help
+ Mailbox implementation of the Broadcom STB for the sole purposes
+ of SCMI communication. This is used by the SCMI drivers to
+ communicate with FW that runs in EL3. This mailbox only implements
+ the agent-to-platform channgel of SCMI but may be augmented in
+ the future to add the platform-to-agent channel.
+
endif
@@ -54,3 +54,5 @@ obj-$(CONFIG_SUN6I_MSGBOX) += sun6i-msgbox.o
obj-$(CONFIG_SPRD_MBOX) += sprd-mailbox.o
obj-$(CONFIG_QCOM_IPCC) += qcom-ipcc.o
+
+obj-$(CONFIG_BRCMSTB_MBOX) += brcmstb-mailbox.o
new file mode 100644
@@ -0,0 +1,167 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2017-2020, Broadcom */
+
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/mailbox_controller.h>
+#include <linux/mailbox_client.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/arm-smccc.h>
+
+#define BRCM_SCMI_SMC_OEM_FUNC 0x400
+#define BRCM_SCMI_MBOX_NUM 0
+#define BRCM_FID(ch) ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \
+ IS_ENABLED(CONFIG_ARM64), \
+ ARM_SMCCC_OWNER_OEM, \
+ BRCM_SCMI_SMC_OEM_FUNC + (ch))
+enum {
+ A2P_CHAN = 0,
+ NUM_CHAN
+};
+
+struct chan_priv {
+ unsigned int mbox_num;
+ unsigned int ch;
+};
+
+struct brcm_mbox {
+ struct mbox_controller controller;
+ int irqs[NUM_CHAN];
+};
+
+static struct mbox_chan *brcm_mbox_of_xlate(struct mbox_controller *controller,
+ const struct of_phandle_args *sp)
+{
+ unsigned int ch = sp->args[0];
+ struct brcm_mbox *mbox
+ = container_of(controller, struct brcm_mbox, controller);
+
+ if (!mbox || ch >= NUM_CHAN)
+ return ERR_PTR(-ENOENT);
+
+ return &mbox->controller.chans[ch];
+}
+
+static int announce_msg(unsigned int mbox_num, unsigned int ch)
+{
+ struct arm_smccc_res res;
+
+ if (ch >= NUM_CHAN)
+ return -EIO;
+ arm_smccc_smc(BRCM_FID(ch), mbox_num, 0, 0, 0, 0, 0, 0, &res);
+ if (res.a0)
+ return -EIO;
+ return 0;
+}
+
+static int brcm_mbox_send_data(struct mbox_chan *chan, void *data)
+{
+ struct chan_priv *priv = chan->con_priv;
+
+ return announce_msg(priv->mbox_num, priv->ch);
+}
+
+static int brcm_mbox_startup(struct mbox_chan *chan)
+{
+ return 0;
+}
+
+static const struct mbox_chan_ops brcm_mbox_ops = {
+ .send_data = brcm_mbox_send_data,
+ .startup = brcm_mbox_startup,
+};
+
+static irqreturn_t brcm_a2p_isr(int irq, void *data)
+{
+ struct mbox_chan *chan = data;
+
+ mbox_chan_received_data(chan, NULL);
+ return IRQ_HANDLED;
+}
+
+static int brcm_mbox_probe(struct platform_device *pdev)
+{
+ struct brcm_mbox *mbox;
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ struct chan_priv *chan_priv;
+ int ret;
+
+ if (!np)
+ return -EINVAL;
+
+ mbox = devm_kzalloc(&pdev->dev, sizeof(*mbox), GFP_KERNEL);
+ if (!mbox)
+ return -ENOMEM;
+
+ /* Allocate channels */
+ mbox->controller.chans = devm_kzalloc(
+ &pdev->dev, NUM_CHAN * sizeof(struct mbox_chan), GFP_KERNEL);
+ if (!mbox->controller.chans)
+ return -ENOMEM;
+ chan_priv = devm_kzalloc(
+ &pdev->dev, NUM_CHAN * sizeof(struct chan_priv), GFP_KERNEL);
+ if (!chan_priv)
+ return -ENOMEM;
+
+ mbox->irqs[A2P_CHAN] = platform_get_irq(pdev, 0);
+ ret = devm_request_irq(&pdev->dev, mbox->irqs[A2P_CHAN], brcm_a2p_isr,
+ IRQF_NO_SUSPEND, "brcm: SCMI a2p intr",
+ &mbox->controller.chans[A2P_CHAN]);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to setup SCMI a2p isr\n");
+ return ret;
+ }
+ chan_priv[A2P_CHAN].mbox_num = BRCM_SCMI_MBOX_NUM;
+ chan_priv[A2P_CHAN].ch = A2P_CHAN;
+ mbox->controller.chans[A2P_CHAN].con_priv = &chan_priv[A2P_CHAN];
+ mbox->controller.num_chans++;
+ mbox->controller.dev = &pdev->dev;
+ mbox->controller.ops = &brcm_mbox_ops;
+ mbox->controller.of_xlate = brcm_mbox_of_xlate;
+ ret = mbox_controller_register(&mbox->controller);
+ if (ret) {
+ dev_err(dev, "failed to register BrcmSTB mbox\n");
+ return ret;
+ }
+
+ platform_set_drvdata(pdev, mbox);
+ return 0;
+}
+
+static int brcm_mbox_remove(struct platform_device *pdev)
+{
+ struct brcm_mbox *mbox = platform_get_drvdata(pdev);
+
+ mbox_controller_unregister(&mbox->controller);
+
+ return 0;
+}
+
+static const struct of_device_id brcm_mbox_of_match[] = {
+ { .compatible = "brcm,brcmstb-mbox", },
+ {}
+};
+MODULE_DEVICE_TABLE(of, brcm_mbox_of_match);
+
+static struct platform_driver brcm_mbox_driver = {
+ .probe = brcm_mbox_probe,
+ .remove = brcm_mbox_remove,
+ .driver = {
+ .name = "brcm_mbox",
+ .of_match_table = brcm_mbox_of_match,
+ },
+};
+
+module_platform_driver(brcm_mbox_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Broadcom STB SCMI Mailbox driver");
+MODULE_AUTHOR("Broadcom");