summaryrefslogtreecommitdiffstats
path: root/drivers/mailbox/mailbox-mpfs.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/mailbox/mailbox-mpfs.c')
-rw-r--r--drivers/mailbox/mailbox-mpfs.c287
1 files changed, 287 insertions, 0 deletions
diff --git a/drivers/mailbox/mailbox-mpfs.c b/drivers/mailbox/mailbox-mpfs.c
new file mode 100644
index 0000000000..20ee283a04
--- /dev/null
+++ b/drivers/mailbox/mailbox-mpfs.c
@@ -0,0 +1,287 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Microchip PolarFire SoC (MPFS) system controller/mailbox controller driver
+ *
+ * Copyright (c) 2020-2022 Microchip Corporation. All rights reserved.
+ *
+ * Author: Conor Dooley <conor.dooley@microchip.com>
+ *
+ */
+
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/mod_devicetable.h>
+#include <linux/platform_device.h>
+#include <linux/mailbox_controller.h>
+#include <soc/microchip/mpfs.h>
+
+#define SERVICES_CR_OFFSET 0x50u
+#define SERVICES_SR_OFFSET 0x54u
+#define MAILBOX_REG_OFFSET 0x800u
+#define MSS_SYS_MAILBOX_DATA_OFFSET 0u
+#define SCB_MASK_WIDTH 16u
+
+/* SCBCTRL service control register */
+
+#define SCB_CTRL_REQ (0)
+#define SCB_CTRL_REQ_MASK BIT(SCB_CTRL_REQ)
+
+#define SCB_CTRL_BUSY (1)
+#define SCB_CTRL_BUSY_MASK BIT(SCB_CTRL_BUSY)
+
+#define SCB_CTRL_ABORT (2)
+#define SCB_CTRL_ABORT_MASK BIT(SCB_CTRL_ABORT)
+
+#define SCB_CTRL_NOTIFY (3)
+#define SCB_CTRL_NOTIFY_MASK BIT(SCB_CTRL_NOTIFY)
+
+#define SCB_CTRL_POS (16)
+#define SCB_CTRL_MASK GENMASK(SCB_CTRL_POS + SCB_MASK_WIDTH - 1, SCB_CTRL_POS)
+
+/* SCBCTRL service status register */
+
+#define SCB_STATUS_REQ (0)
+#define SCB_STATUS_REQ_MASK BIT(SCB_STATUS_REQ)
+
+#define SCB_STATUS_BUSY (1)
+#define SCB_STATUS_BUSY_MASK BIT(SCB_STATUS_BUSY)
+
+#define SCB_STATUS_ABORT (2)
+#define SCB_STATUS_ABORT_MASK BIT(SCB_STATUS_ABORT)
+
+#define SCB_STATUS_NOTIFY (3)
+#define SCB_STATUS_NOTIFY_MASK BIT(SCB_STATUS_NOTIFY)
+
+#define SCB_STATUS_POS (16)
+#define SCB_STATUS_MASK GENMASK(SCB_STATUS_POS + SCB_MASK_WIDTH - 1, SCB_STATUS_POS)
+
+struct mpfs_mbox {
+ struct mbox_controller controller;
+ struct device *dev;
+ int irq;
+ void __iomem *ctrl_base;
+ void __iomem *mbox_base;
+ void __iomem *int_reg;
+ struct mbox_chan chans[1];
+ struct mpfs_mss_response *response;
+ u16 resp_offset;
+};
+
+static bool mpfs_mbox_busy(struct mpfs_mbox *mbox)
+{
+ u32 status;
+
+ status = readl_relaxed(mbox->ctrl_base + SERVICES_SR_OFFSET);
+
+ return status & SCB_STATUS_BUSY_MASK;
+}
+
+static bool mpfs_mbox_last_tx_done(struct mbox_chan *chan)
+{
+ struct mpfs_mbox *mbox = (struct mpfs_mbox *)chan->con_priv;
+ struct mpfs_mss_response *response = mbox->response;
+ u32 val;
+
+ if (mpfs_mbox_busy(mbox))
+ return false;
+
+ /*
+ * The service status is stored in bits 31:16 of the SERVICES_SR
+ * register & is only valid when the system controller is not busy.
+ * Failed services are intended to generated interrupts, but in reality
+ * this does not happen, so the status must be checked here.
+ */
+ val = readl_relaxed(mbox->ctrl_base + SERVICES_SR_OFFSET);
+ response->resp_status = (val & SCB_STATUS_MASK) >> SCB_STATUS_POS;
+
+ return true;
+}
+
+static int mpfs_mbox_send_data(struct mbox_chan *chan, void *data)
+{
+ struct mpfs_mbox *mbox = (struct mpfs_mbox *)chan->con_priv;
+ struct mpfs_mss_msg *msg = data;
+ u32 tx_trigger;
+ u16 opt_sel;
+ u32 val = 0u;
+
+ mbox->response = msg->response;
+ mbox->resp_offset = msg->resp_offset;
+
+ if (mpfs_mbox_busy(mbox))
+ return -EBUSY;
+
+ if (msg->cmd_data_size) {
+ u32 index;
+ u8 extra_bits = msg->cmd_data_size & 3;
+ u32 *word_buf = (u32 *)msg->cmd_data;
+
+ for (index = 0; index < (msg->cmd_data_size / 4); index++)
+ writel_relaxed(word_buf[index],
+ mbox->mbox_base + msg->mbox_offset + index * 0x4);
+ if (extra_bits) {
+ u8 i;
+ u8 byte_off = ALIGN_DOWN(msg->cmd_data_size, 4);
+ u8 *byte_buf = msg->cmd_data + byte_off;
+
+ val = readl_relaxed(mbox->mbox_base + msg->mbox_offset + index * 0x4);
+
+ for (i = 0u; i < extra_bits; i++) {
+ val &= ~(0xffu << (i * 8u));
+ val |= (byte_buf[i] << (i * 8u));
+ }
+
+ writel_relaxed(val, mbox->mbox_base + msg->mbox_offset + index * 0x4);
+ }
+ }
+
+ opt_sel = ((msg->mbox_offset << 7u) | (msg->cmd_opcode & 0x7fu));
+
+ tx_trigger = (opt_sel << SCB_CTRL_POS) & SCB_CTRL_MASK;
+ tx_trigger |= SCB_CTRL_REQ_MASK | SCB_STATUS_NOTIFY_MASK;
+ writel_relaxed(tx_trigger, mbox->ctrl_base + SERVICES_CR_OFFSET);
+
+ return 0;
+}
+
+static void mpfs_mbox_rx_data(struct mbox_chan *chan)
+{
+ struct mpfs_mbox *mbox = (struct mpfs_mbox *)chan->con_priv;
+ struct mpfs_mss_response *response = mbox->response;
+ u16 num_words = ALIGN((response->resp_size), (4)) / 4U;
+ u32 i;
+
+ if (!response->resp_msg) {
+ dev_err(mbox->dev, "failed to assign memory for response %d\n", -ENOMEM);
+ return;
+ }
+
+ /*
+ * We should *never* get an interrupt while the controller is
+ * still in the busy state. If we do, something has gone badly
+ * wrong & the content of the mailbox would not be valid.
+ */
+ if (mpfs_mbox_busy(mbox)) {
+ dev_err(mbox->dev, "got an interrupt but system controller is busy\n");
+ response->resp_status = 0xDEAD;
+ return;
+ }
+
+ for (i = 0; i < num_words; i++) {
+ response->resp_msg[i] =
+ readl_relaxed(mbox->mbox_base
+ + mbox->resp_offset + i * 0x4);
+ }
+
+ mbox_chan_received_data(chan, response);
+}
+
+static irqreturn_t mpfs_mbox_inbox_isr(int irq, void *data)
+{
+ struct mbox_chan *chan = data;
+ struct mpfs_mbox *mbox = (struct mpfs_mbox *)chan->con_priv;
+
+ writel_relaxed(0, mbox->int_reg);
+
+ mpfs_mbox_rx_data(chan);
+
+ return IRQ_HANDLED;
+}
+
+static int mpfs_mbox_startup(struct mbox_chan *chan)
+{
+ struct mpfs_mbox *mbox = (struct mpfs_mbox *)chan->con_priv;
+ int ret = 0;
+
+ if (!mbox)
+ return -EINVAL;
+
+ ret = devm_request_irq(mbox->dev, mbox->irq, mpfs_mbox_inbox_isr, 0, "mpfs-mailbox", chan);
+ if (ret)
+ dev_err(mbox->dev, "failed to register mailbox interrupt:%d\n", ret);
+
+ return ret;
+}
+
+static void mpfs_mbox_shutdown(struct mbox_chan *chan)
+{
+ struct mpfs_mbox *mbox = (struct mpfs_mbox *)chan->con_priv;
+
+ devm_free_irq(mbox->dev, mbox->irq, chan);
+}
+
+static const struct mbox_chan_ops mpfs_mbox_ops = {
+ .send_data = mpfs_mbox_send_data,
+ .startup = mpfs_mbox_startup,
+ .shutdown = mpfs_mbox_shutdown,
+ .last_tx_done = mpfs_mbox_last_tx_done,
+};
+
+static int mpfs_mbox_probe(struct platform_device *pdev)
+{
+ struct mpfs_mbox *mbox;
+ struct resource *regs;
+ int ret;
+
+ mbox = devm_kzalloc(&pdev->dev, sizeof(*mbox), GFP_KERNEL);
+ if (!mbox)
+ return -ENOMEM;
+
+ mbox->ctrl_base = devm_platform_get_and_ioremap_resource(pdev, 0, &regs);
+ if (IS_ERR(mbox->ctrl_base))
+ return PTR_ERR(mbox->ctrl_base);
+
+ mbox->int_reg = devm_platform_get_and_ioremap_resource(pdev, 1, &regs);
+ if (IS_ERR(mbox->int_reg))
+ return PTR_ERR(mbox->int_reg);
+
+ mbox->mbox_base = devm_platform_get_and_ioremap_resource(pdev, 2, &regs);
+ if (IS_ERR(mbox->mbox_base)) // account for the old dt-binding w/ 2 regs
+ mbox->mbox_base = mbox->ctrl_base + MAILBOX_REG_OFFSET;
+
+ mbox->irq = platform_get_irq(pdev, 0);
+ if (mbox->irq < 0)
+ return mbox->irq;
+
+ mbox->dev = &pdev->dev;
+
+ mbox->chans[0].con_priv = mbox;
+ mbox->controller.dev = mbox->dev;
+ mbox->controller.num_chans = 1;
+ mbox->controller.chans = mbox->chans;
+ mbox->controller.ops = &mpfs_mbox_ops;
+ mbox->controller.txdone_poll = true;
+ mbox->controller.txpoll_period = 10u;
+
+ ret = devm_mbox_controller_register(&pdev->dev, &mbox->controller);
+ if (ret) {
+ dev_err(&pdev->dev, "Registering MPFS mailbox controller failed\n");
+ return ret;
+ }
+ dev_info(&pdev->dev, "Registered MPFS mailbox controller driver\n");
+
+ return 0;
+}
+
+static const struct of_device_id mpfs_mbox_of_match[] = {
+ {.compatible = "microchip,mpfs-mailbox", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, mpfs_mbox_of_match);
+
+static struct platform_driver mpfs_mbox_driver = {
+ .driver = {
+ .name = "mpfs-mailbox",
+ .of_match_table = mpfs_mbox_of_match,
+ },
+ .probe = mpfs_mbox_probe,
+};
+module_platform_driver(mpfs_mbox_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Conor Dooley <conor.dooley@microchip.com>");
+MODULE_DESCRIPTION("MPFS mailbox controller driver");