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-rw-r--r--drivers/mailbox/Makefile2
-rw-r--r--drivers/mailbox/arm_mhu_db.c354
2 files changed, 355 insertions, 1 deletions
diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
index 60d224b723a1..2e06e02b2e03 100644
--- a/drivers/mailbox/Makefile
+++ b/drivers/mailbox/Makefile
@@ -5,7 +5,7 @@ obj-$(CONFIG_MAILBOX) += mailbox.o
obj-$(CONFIG_MAILBOX_TEST) += mailbox-test.o
-obj-$(CONFIG_ARM_MHU) += arm_mhu.o
+obj-$(CONFIG_ARM_MHU) += arm_mhu.o arm_mhu_db.o
obj-$(CONFIG_IMX_MBOX) += imx-mailbox.o
diff --git a/drivers/mailbox/arm_mhu_db.c b/drivers/mailbox/arm_mhu_db.c
new file mode 100644
index 000000000000..275efe4cca0c
--- /dev/null
+++ b/drivers/mailbox/arm_mhu_db.c
@@ -0,0 +1,354 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2013-2015 Fujitsu Semiconductor Ltd.
+ * Copyright (C) 2015 Linaro Ltd.
+ * Based on ARM MHU driver by Jassi Brar <jaswinder.singh@linaro.org>
+ * Copyright (C) 2020 ARM Ltd.
+ */
+
+#include <linux/amba/bus.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mailbox_controller.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+
+#define INTR_STAT_OFS 0x0
+#define INTR_SET_OFS 0x8
+#define INTR_CLR_OFS 0x10
+
+#define MHU_LP_OFFSET 0x0
+#define MHU_HP_OFFSET 0x20
+#define MHU_SEC_OFFSET 0x200
+#define TX_REG_OFFSET 0x100
+
+#define MHU_CHANS 3 /* Secure, Non-Secure High and Low Priority */
+#define MHU_CHAN_MAX 20 /* Max channels to save on unused RAM */
+#define MHU_NUM_DOORBELLS 32
+
+struct mhu_db_link {
+ unsigned int irq;
+ void __iomem *tx_reg;
+ void __iomem *rx_reg;
+};
+
+struct arm_mhu {
+ void __iomem *base;
+ struct mhu_db_link mlink[MHU_CHANS];
+ struct mbox_controller mbox;
+ struct device *dev;
+};
+
+/**
+ * ARM MHU Mailbox allocated channel information
+ *
+ * @mhu: Pointer to parent mailbox device
+ * @pchan: Physical channel within which this doorbell resides in
+ * @doorbell: doorbell number pertaining to this channel
+ */
+struct mhu_db_channel {
+ struct arm_mhu *mhu;
+ unsigned int pchan;
+ unsigned int doorbell;
+};
+
+static inline struct mbox_chan *
+mhu_db_mbox_to_channel(struct mbox_controller *mbox, unsigned int pchan,
+ unsigned int doorbell)
+{
+ int i;
+ struct mhu_db_channel *chan_info;
+
+ for (i = 0; i < mbox->num_chans; i++) {
+ chan_info = mbox->chans[i].con_priv;
+ if (chan_info && chan_info->pchan == pchan &&
+ chan_info->doorbell == doorbell)
+ return &mbox->chans[i];
+ }
+
+ return NULL;
+}
+
+static void mhu_db_mbox_clear_irq(struct mbox_chan *chan)
+{
+ struct mhu_db_channel *chan_info = chan->con_priv;
+ void __iomem *base = chan_info->mhu->mlink[chan_info->pchan].rx_reg;
+
+ writel_relaxed(BIT(chan_info->doorbell), base + INTR_CLR_OFS);
+}
+
+static unsigned int mhu_db_mbox_irq_to_pchan_num(struct arm_mhu *mhu, int irq)
+{
+ unsigned int pchan;
+
+ for (pchan = 0; pchan < MHU_CHANS; pchan++)
+ if (mhu->mlink[pchan].irq == irq)
+ break;
+ return pchan;
+}
+
+static struct mbox_chan *
+mhu_db_mbox_irq_to_channel(struct arm_mhu *mhu, unsigned int pchan)
+{
+ unsigned long bits;
+ unsigned int doorbell;
+ struct mbox_chan *chan = NULL;
+ struct mbox_controller *mbox = &mhu->mbox;
+ void __iomem *base = mhu->mlink[pchan].rx_reg;
+
+ bits = readl_relaxed(base + INTR_STAT_OFS);
+ if (!bits)
+ /* No IRQs fired in specified physical channel */
+ return NULL;
+
+ /* An IRQ has fired, find the associated channel */
+ for (doorbell = 0; bits; doorbell++) {
+ if (!test_and_clear_bit(doorbell, &bits))
+ continue;
+
+ chan = mhu_db_mbox_to_channel(mbox, pchan, doorbell);
+ if (chan)
+ break;
+ dev_err(mbox->dev,
+ "Channel not registered: pchan: %d doorbell: %d\n",
+ pchan, doorbell);
+ }
+
+ return chan;
+}
+
+static irqreturn_t mhu_db_mbox_rx_handler(int irq, void *data)
+{
+ struct mbox_chan *chan;
+ struct arm_mhu *mhu = data;
+ unsigned int pchan = mhu_db_mbox_irq_to_pchan_num(mhu, irq);
+
+ while (NULL != (chan = mhu_db_mbox_irq_to_channel(mhu, pchan))) {
+ mbox_chan_received_data(chan, NULL);
+ mhu_db_mbox_clear_irq(chan);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static bool mhu_db_last_tx_done(struct mbox_chan *chan)
+{
+ struct mhu_db_channel *chan_info = chan->con_priv;
+ void __iomem *base = chan_info->mhu->mlink[chan_info->pchan].tx_reg;
+
+ if (readl_relaxed(base + INTR_STAT_OFS) & BIT(chan_info->doorbell))
+ return false;
+
+ return true;
+}
+
+static int mhu_db_send_data(struct mbox_chan *chan, void *data)
+{
+ struct mhu_db_channel *chan_info = chan->con_priv;
+ void __iomem *base = chan_info->mhu->mlink[chan_info->pchan].tx_reg;
+
+ /* Send event to co-processor */
+ writel_relaxed(BIT(chan_info->doorbell), base + INTR_SET_OFS);
+
+ return 0;
+}
+
+static int mhu_db_startup(struct mbox_chan *chan)
+{
+ mhu_db_mbox_clear_irq(chan);
+ return 0;
+}
+
+static void mhu_db_shutdown(struct mbox_chan *chan)
+{
+ struct mhu_db_channel *chan_info = chan->con_priv;
+ struct mbox_controller *mbox = &chan_info->mhu->mbox;
+ int i;
+
+ for (i = 0; i < mbox->num_chans; i++)
+ if (chan == &mbox->chans[i])
+ break;
+
+ if (mbox->num_chans == i) {
+ dev_warn(mbox->dev, "Request to free non-existent channel\n");
+ return;
+ }
+
+ /* Reset channel */
+ mhu_db_mbox_clear_irq(chan);
+ kfree(chan->con_priv);
+ chan->con_priv = NULL;
+}
+
+static struct mbox_chan *mhu_db_mbox_xlate(struct mbox_controller *mbox,
+ const struct of_phandle_args *spec)
+{
+ struct arm_mhu *mhu = dev_get_drvdata(mbox->dev);
+ struct mhu_db_channel *chan_info;
+ struct mbox_chan *chan;
+ unsigned int pchan = spec->args[0];
+ unsigned int doorbell = spec->args[1];
+ int i;
+
+ /* Bounds checking */
+ if (pchan >= MHU_CHANS || doorbell >= MHU_NUM_DOORBELLS) {
+ dev_err(mbox->dev,
+ "Invalid channel requested pchan: %d doorbell: %d\n",
+ pchan, doorbell);
+ return ERR_PTR(-EINVAL);
+ }
+
+ /* Is requested channel free? */
+ chan = mhu_db_mbox_to_channel(mbox, pchan, doorbell);
+ if (chan) {
+ dev_err(mbox->dev, "Channel in use: pchan: %d doorbell: %d\n",
+ pchan, doorbell);
+ return ERR_PTR(-EBUSY);
+ }
+
+ /* Find the first free slot */
+ for (i = 0; i < mbox->num_chans; i++)
+ if (!mbox->chans[i].con_priv)
+ break;
+
+ if (mbox->num_chans == i) {
+ dev_err(mbox->dev, "No free channels left\n");
+ return ERR_PTR(-EBUSY);
+ }
+
+ chan = &mbox->chans[i];
+
+ chan_info = devm_kzalloc(mbox->dev, sizeof(*chan_info), GFP_KERNEL);
+ if (!chan_info)
+ return ERR_PTR(-ENOMEM);
+
+ chan_info->mhu = mhu;
+ chan_info->pchan = pchan;
+ chan_info->doorbell = doorbell;
+
+ chan->con_priv = chan_info;
+
+ dev_dbg(mbox->dev, "mbox: created channel phys: %d doorbell: %d\n",
+ pchan, doorbell);
+
+ return chan;
+}
+
+static const struct mbox_chan_ops mhu_db_ops = {
+ .send_data = mhu_db_send_data,
+ .startup = mhu_db_startup,
+ .shutdown = mhu_db_shutdown,
+ .last_tx_done = mhu_db_last_tx_done,
+};
+
+static int mhu_db_probe(struct amba_device *adev, const struct amba_id *id)
+{
+ u32 cell_count;
+ int i, err, max_chans;
+ struct arm_mhu *mhu;
+ struct mbox_chan *chans;
+ struct device *dev = &adev->dev;
+ struct device_node *np = dev->of_node;
+ int mhu_reg[MHU_CHANS] = {
+ MHU_LP_OFFSET, MHU_HP_OFFSET, MHU_SEC_OFFSET,
+ };
+
+ if (!of_device_is_compatible(np, "arm,mhu-doorbell"))
+ return -ENODEV;
+
+ err = of_property_read_u32(np, "#mbox-cells", &cell_count);
+ if (err) {
+ dev_err(dev, "failed to read #mbox-cells in '%pOF'\n", np);
+ return err;
+ }
+
+ if (cell_count == 2) {
+ max_chans = MHU_CHAN_MAX;
+ } else {
+ dev_err(dev, "incorrect value of #mbox-cells in '%pOF'\n", np);
+ return -EINVAL;
+ }
+
+ mhu = devm_kzalloc(dev, sizeof(*mhu), GFP_KERNEL);
+ if (!mhu)
+ return -ENOMEM;
+
+ mhu->base = devm_ioremap_resource(dev, &adev->res);
+ if (IS_ERR(mhu->base)) {
+ dev_err(dev, "ioremap failed\n");
+ return PTR_ERR(mhu->base);
+ }
+
+ chans = devm_kcalloc(dev, max_chans, sizeof(*chans), GFP_KERNEL);
+ if (!chans)
+ return -ENOMEM;
+
+ mhu->dev = dev;
+ mhu->mbox.dev = dev;
+ mhu->mbox.chans = chans;
+ mhu->mbox.num_chans = max_chans;
+ mhu->mbox.txdone_irq = false;
+ mhu->mbox.txdone_poll = true;
+ mhu->mbox.txpoll_period = 1;
+
+ mhu->mbox.of_xlate = mhu_db_mbox_xlate;
+ amba_set_drvdata(adev, mhu);
+
+ mhu->mbox.ops = &mhu_db_ops;
+
+ err = devm_mbox_controller_register(dev, &mhu->mbox);
+ if (err) {
+ dev_err(dev, "Failed to register mailboxes %d\n", err);
+ return err;
+ }
+
+ for (i = 0; i < MHU_CHANS; i++) {
+ int irq = mhu->mlink[i].irq = adev->irq[i];
+
+ if (irq <= 0) {
+ dev_dbg(dev, "No IRQ found for Channel %d\n", i);
+ continue;
+ }
+
+ mhu->mlink[i].rx_reg = mhu->base + mhu_reg[i];
+ mhu->mlink[i].tx_reg = mhu->mlink[i].rx_reg + TX_REG_OFFSET;
+
+ err = devm_request_threaded_irq(dev, irq, NULL,
+ mhu_db_mbox_rx_handler,
+ IRQF_ONESHOT, "mhu_db_link", mhu);
+ if (err) {
+ dev_err(dev, "Can't claim IRQ %d\n", irq);
+ mbox_controller_unregister(&mhu->mbox);
+ return err;
+ }
+ }
+
+ dev_info(dev, "ARM MHU Doorbell mailbox registered\n");
+ return 0;
+}
+
+static struct amba_id mhu_ids[] = {
+ {
+ .id = 0x1bb098,
+ .mask = 0xffffff,
+ },
+ { 0, 0 },
+};
+MODULE_DEVICE_TABLE(amba, mhu_ids);
+
+static struct amba_driver arm_mhu_db_driver = {
+ .drv = {
+ .name = "mhu-doorbell",
+ },
+ .id_table = mhu_ids,
+ .probe = mhu_db_probe,
+};
+module_amba_driver(arm_mhu_db_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("ARM MHU Doorbell Driver");
+MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-04 14:43:09 +0000