[PATCH 3/6] mailbox: add PolarFire SoC mailbox driver
Jamie Gibbons
jamie.gibbons at microchip.com
Fri Aug 1 14:36:23 CEST 2025
This driver adds support for the single mailbox channel of the MSS
system controller on the Microchip PolarFire SoC.
Signed-off-by: Jamie Gibbons <jamie.gibbons at microchip.com>
---
drivers/mailbox/Kconfig | 7 ++
drivers/mailbox/Makefile | 1 +
drivers/mailbox/mpfs-mbox.c | 177 ++++++++++++++++++++++++++++++++++++
include/mpfs-mailbox.h | 67 ++++++++++++++
4 files changed, 252 insertions(+)
create mode 100644 drivers/mailbox/mpfs-mbox.c
create mode 100644 include/mpfs-mailbox.h
diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
index 4d9f004ebad..5a31ac707dc 100644
--- a/drivers/mailbox/Kconfig
+++ b/drivers/mailbox/Kconfig
@@ -28,6 +28,13 @@ config IMX_MU_MBOX
Enable support for i.MX Messaging Unit for communication with other
processors on the SoC using mailbox interface
+config MPFS_MBOX
+ bool "Enable MPFS system controler support"
+ depends on DM_MAILBOX && ARCH_RV64I
+ help
+ Enable support for the mailboxes that provide a comminucation
+ channel with the system controller integrated on PolarFire SoC.
+
config SANDBOX_MBOX
bool "Enable the sandbox mailbox test driver"
depends on DM_MAILBOX && SANDBOX
diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
index e8c745f7d79..b54fbdfff15 100644
--- a/drivers/mailbox/Makefile
+++ b/drivers/mailbox/Makefile
@@ -6,6 +6,7 @@
obj-$(CONFIG_$(PHASE_)DM_MAILBOX) += mailbox-uclass.o
obj-$(CONFIG_APPLE_MBOX) += apple-mbox.o
obj-$(CONFIG_IMX_MU_MBOX) += imx-mailbox.o
+obj-$(CONFIG_MPFS_MBOX) += mpfs-mbox.o
obj-$(CONFIG_SANDBOX_MBOX) += sandbox-mbox.o
obj-$(CONFIG_SANDBOX_MBOX) += sandbox-mbox-test.o
obj-$(CONFIG_STM32_IPCC) += stm32-ipcc.o
diff --git a/drivers/mailbox/mpfs-mbox.c b/drivers/mailbox/mpfs-mbox.c
new file mode 100644
index 00000000000..55238847ecd
--- /dev/null
+++ b/drivers/mailbox/mpfs-mbox.c
@@ -0,0 +1,177 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Microchip's PolarFire SoC (MPFS) Mailbox Driver
+ *
+ * Copyright (C) 2024 Microchip Technology Inc. All rights reserved.
+ *
+ * Author: Jamie Gibbons <jamie.gibbons at microchip.com>
+ *
+ */
+
+#include <asm/io.h>
+#include <dm.h>
+#include <dm/device-internal.h>
+#include <dm/device.h>
+#include <dm/device_compat.h>
+#include <dm/devres.h>
+#include <dm/ofnode.h>
+#include <linux/bitops.h>
+#include <linux/compat.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <log.h>
+#include <mailbox-uclass.h>
+#include <malloc.h>
+#include <mpfs-mailbox.h>
+
+#define SERVICES_CR_OFFSET 0x50u
+#define SERVICES_SR_OFFSET 0x54u
+
+#define SERVICE_CR_REQ_MASK 0x1u
+#define SERVICE_SR_BUSY_MASK 0x2u
+#define SERVICE_SR_STATUS_SHIFT 16
+#define SERVICE_CR_COMMAND_SHIFT 16
+#define MASK_8BIT 0xFF
+
+struct mpfs_mbox {
+ struct udevice *dev;
+ void __iomem *ctrl_base;
+ void __iomem *mbox_base;
+ struct mbox_chan *chan;
+};
+
+static bool mpfs_mbox_busy(struct mbox_chan *chan)
+{
+ struct mpfs_mbox *mbox = dev_get_priv(chan->dev);
+ uint16_t status;
+
+ status = readl(mbox->ctrl_base + SERVICES_SR_OFFSET);
+
+ return status & SERVICE_SR_BUSY_MASK;
+}
+
+static int mpfs_mbox_send(struct mbox_chan *chan, const void *data)
+{
+ struct mpfs_mbox *mbox = dev_get_priv(chan->dev);
+ struct mpfs_mss_msg *msg = (struct mpfs_mss_msg *)data;
+ u32 mailbox_val, cmd_shifted, value;
+ u8 *byte_buf;
+ u8 idx, byte_idx, byte_offset;
+
+ u32 *word_buf = (u32 *)msg->cmd_data;
+
+ if (mpfs_mbox_busy(chan))
+ return -EBUSY;
+
+ for (idx = 0; idx < (msg->cmd_data_size / BYTES_4); idx++)
+ writel(word_buf[idx], mbox->mbox_base + msg->mbox_offset + idx * BYTES_4);
+
+ if ((msg->cmd_data_size % BYTES_4) > 0) {
+ byte_offset = (msg->cmd_data_size / BYTES_4) * BYTES_4;
+ byte_buf = (u8 *)(msg->cmd_data + byte_offset);
+ mailbox_val = readl(mbox->mbox_base + msg->mbox_offset + idx * BYTES_4);
+
+ for (byte_idx = 0; byte_idx < (msg->cmd_data_size % BYTES_4); byte_idx++) {
+ mailbox_val &= ~(MASK_8BIT << (byte_idx * 0x8u));
+ mailbox_val |= (u32)byte_buf[byte_idx] << (byte_idx * 0x8u);
+ }
+ writel(mailbox_val, mbox->mbox_base + msg->mbox_offset + idx * BYTES_4);
+ }
+
+ cmd_shifted = msg->cmd_opcode << SERVICE_CR_COMMAND_SHIFT;
+ cmd_shifted |= SERVICE_CR_REQ_MASK;
+ writel(cmd_shifted, mbox->ctrl_base + SERVICES_CR_OFFSET);
+
+ do {
+ value = readl(mbox->ctrl_base + SERVICES_CR_OFFSET);
+ } while (SERVICE_CR_REQ_MASK == (value & SERVICE_CR_REQ_MASK));
+
+ do {
+ value = readl(mbox->ctrl_base + SERVICES_SR_OFFSET);
+ } while (SERVICE_SR_BUSY_MASK == (value & SERVICE_SR_BUSY_MASK));
+
+ msg->response->resp_status = (value >> SERVICE_SR_STATUS_SHIFT);
+ if (msg->response->resp_status)
+ return -EBADMSG;
+
+ return 0;
+}
+
+static int mpfs_mbox_recv(struct mbox_chan *chan, void *data)
+{
+ struct mpfs_mbox *mbox = dev_get_priv(chan->dev);
+ struct mpfs_mss_msg *msg = data;
+ struct mpfs_mss_response *response = msg->response;
+ u8 idx;
+
+ if (!response->resp_msg) {
+ dev_err(chan->dev, "failed to assign memory for response %d\n", -ENOMEM);
+ return -EINVAL;
+ }
+
+ if (mpfs_mbox_busy(chan)) {
+ dev_err(chan->dev, "mailbox is busy\n");
+ response->resp_status = 0xDEAD;
+ return -EINVAL;
+ }
+
+ for (idx = 0; idx < response->resp_size; idx++)
+ *((u8 *)(response->resp_msg) + idx) = readb(mbox->mbox_base + msg->resp_offset + idx);
+
+ return 0;
+}
+
+static const struct mbox_ops mpfs_mbox_ops = {
+ .send = mpfs_mbox_send,
+ .recv = mpfs_mbox_recv,
+};
+
+static int mpfs_mbox_probe(struct udevice *dev)
+{
+ struct mpfs_mbox *mbox;
+ struct resource regs;
+ ofnode node;
+ int ret;
+
+ node = dev_ofnode(dev);
+
+ mbox = devm_kzalloc(dev, sizeof(*mbox), GFP_KERNEL);
+ if (!mbox)
+ return -ENOMEM;
+
+ ret = ofnode_read_resource(node, 0, ®s);
+ if (ret) {
+ dev_err(dev, "No reg property for controller base\n");
+ return ret;
+ };
+
+ mbox->ctrl_base = devm_ioremap(dev, regs.start, regs.start - regs.end);
+
+ ret = ofnode_read_resource(node, 2, ®s);
+ if (ret) {
+ dev_err(dev, "No reg property for mailbox base\n");
+ return ret;
+ };
+
+ mbox->mbox_base = devm_ioremap(dev, regs.start, regs.start - regs.end);
+
+ mbox->dev = dev;
+ dev_set_priv(dev, mbox);
+ mbox->chan->con_priv = mbox;
+
+ return 0;
+}
+
+static const struct udevice_id mpfs_mbox_ids[] = {
+ {.compatible = "microchip,mpfs-mailbox"},
+ { }
+};
+
+U_BOOT_DRIVER(mpfs_mbox) = {
+ .name = "mpfs-mbox",
+ .id = UCLASS_MAILBOX,
+ .of_match = mpfs_mbox_ids,
+ .probe = mpfs_mbox_probe,
+ .priv_auto = sizeof(struct mpfs_mbox),
+ .ops = &mpfs_mbox_ops,
+};
diff --git a/include/mpfs-mailbox.h b/include/mpfs-mailbox.h
new file mode 100644
index 00000000000..fe83364ed4c
--- /dev/null
+++ b/include/mpfs-mailbox.h
@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ *
+ * Microchip PolarFire SoC (MPFS)
+ *
+ * Copyright (c) 2020 Microchip Corporation. All rights reserved.
+ *
+ *
+ */
+
+#ifndef _MPFS_MAILBOX_H__
+#define _MPFS_MAILBOX_H__
+
+#include <linux/types.h>
+
+#define BYTES_4 4
+
+struct udevice;
+
+/**
+ * struct mpfs_mss_msg - PolarFire SoC message structure
+ * @cmd_opcode: Command opcode
+ * @cmd_data_size: Size of the command data.
+ * @response: Pointer to the response data.
+ * @cmd_data: Pointer to the command data.
+ * @mbox_offset: Mailbox offset
+ * @resp_offset: Response offset
+ *
+ */
+struct mpfs_mss_msg
+{
+ u8 cmd_opcode;
+ u16 cmd_data_size;
+ struct mpfs_mss_response *response;
+ u8 *cmd_data;
+ u16 mbox_offset;
+ u16 resp_offset;
+};
+
+/**
+ * struct mpfs_mss_response - PolarFire SoC response structure
+ * @resp_status: Reponse status
+ * @resp_msg: Pointer to response message.
+ * @resp_size: Size of the response message.
+ *
+ */
+struct mpfs_mss_response
+{
+ u32 resp_status;
+ u32 *resp_msg;
+ u16 resp_size;
+};
+
+struct mpfs_syscontroller_priv;
+
+struct mpfs_sys_serv {
+ struct udevice *dev;
+ struct mpfs_syscontroller_priv *sys_controller;
+ struct mpfs_mss_msg *msg;
+};
+
+int mpfs_syscontroller_run_service(struct mpfs_syscontroller_priv *sys_controller, struct mpfs_mss_msg *msg);
+int mpfs_syscontroller_read_sernum(struct mpfs_sys_serv *sys_serv_priv, u8 *device_serial_number);
+void mpfs_syscontroller_process_dtbo(struct mpfs_sys_serv *sys_serv_priv);
+struct mpfs_syscontroller_priv *mpfs_syscontroller_get(struct udevice *dev);
+
+#endif /* __MPFS_MAILBOX_H__ */
\ No newline at end of file
--
2.43.0
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