[PATCH v6 2/7] mailbox: arm_mhu: add driver for ARM MHU controller
Vincent Yang
vincent.yang.fujitsu at gmail.com
Thu Feb 5 18:08:48 PST 2015
From: Jassi Brar <jaswinder.singh at linaro.org>
Add driver for the ARM Primecell Message-Handling-Unit(MHU) controller.
Signed-off-by: Jassi Brar <jaswinder.singh at linaro.org>
Signed-off-by: Andy Green <andy.green at linaro.org>
Signed-off-by: Vincent Yang <Vincent.Yang at tw.fujitsu.com>
Signed-off-by: Tetsuya Nuriya <nuriya.tetsuya at jp.fujitsu.com>
---
.../devicetree/bindings/mailbox/arm-mhu.txt | 35 ++++
drivers/mailbox/Kconfig | 7 +
drivers/mailbox/Makefile | 2 +
drivers/mailbox/arm_mhu.c | 196 +++++++++++++++++++++
4 files changed, 240 insertions(+)
create mode 100644 Documentation/devicetree/bindings/mailbox/arm-mhu.txt
create mode 100644 drivers/mailbox/arm_mhu.c
diff --git a/Documentation/devicetree/bindings/mailbox/arm-mhu.txt b/Documentation/devicetree/bindings/mailbox/arm-mhu.txt
new file mode 100644
index 0000000..986a205
--- /dev/null
+++ b/Documentation/devicetree/bindings/mailbox/arm-mhu.txt
@@ -0,0 +1,35 @@
+ARM MHU Mailbox Driver
+======================
+
+The ARM's Message-Handling-Unit (MHU) is a mailbox controller that has
+3 independent channels/links to communicate with remote processor(s).
+ MHU links are hardwired on a platform. A link raises interrupt for any
+received data. However, there is no specified way of knowing if the sent
+data has been read by the remote. This driver assumes the sender polls
+STAT register and the remote clears it after having read the data.
+
+Mailbox Device Node:
+====================
+
+Required properties:
+--------------------
+- compatible: Shall be "arm,mhu" & "arm,primecell"
+- reg: Contains the mailbox register address range (base
+ address and length)
+- #mbox-cells Shall be 1
+- interrupts: Contains the interrupt information corresponding to
+ each of the 3 links of MHU.
+
+Example:
+--------
+
+ mhu: mailbox at 2b1f0000 {
+ #mbox-cells = <1>;
+ compatible = "arm,mhu", "arm,primecell";
+ reg = <0 0x2b1f0000 0x1000>;
+ interrupts = <0 36 4>,
+ <0 35 4>,
+ <0 37 4>;
+ clocks = <&clock 0 2 1>;
+ clock-names = "apb_pclk";
+ };
diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
index c04fed9..9238440 100644
--- a/drivers/mailbox/Kconfig
+++ b/drivers/mailbox/Kconfig
@@ -6,6 +6,13 @@ menuconfig MAILBOX
signals. Say Y if your platform supports hardware mailboxes.
if MAILBOX
+
+config ARM_MHU
+ tristate "ARM MHU Mailbox"
+ depends on ARM
+ help
+ Say Y here if you want to build the ARM MHU controller driver
+
config PL320_MBOX
bool "ARM PL320 Mailbox"
depends on ARM_AMBA
diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
index dd412c2..c83791d 100644
--- a/drivers/mailbox/Makefile
+++ b/drivers/mailbox/Makefile
@@ -2,6 +2,8 @@
obj-$(CONFIG_MAILBOX) += mailbox.o
+obj-$(CONFIG_ARM_MHU) += arm_mhu.o
+
obj-$(CONFIG_PL320_MBOX) += pl320-ipc.o
obj-$(CONFIG_OMAP2PLUS_MBOX) += omap-mailbox.o
diff --git a/drivers/mailbox/arm_mhu.c b/drivers/mailbox/arm_mhu.c
new file mode 100644
index 0000000..d6fd1cd
--- /dev/null
+++ b/drivers/mailbox/arm_mhu.c
@@ -0,0 +1,196 @@
+/*
+ * Copyright (C) 2013-2015 Fujitsu Semiconductor Ltd.
+ * Copyright (C) 2015 Linaro Ltd.
+ * Author: Jassi Brar <jaswinder.singh at linaro.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/mutex.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/amba/bus.h>
+#include <linux/mailbox_controller.h>
+
+#define INTR_STAT_OFS 0x0
+#define INTR_SET_OFS 0x8
+#define INTR_CLR_OFS 0x10
+
+struct mhu_link {
+ unsigned irq;
+ void __iomem *tx_reg;
+ void __iomem *rx_reg;
+};
+
+struct arm_mhu {
+ void __iomem *base;
+ struct mhu_link mlink[3];
+ struct mbox_chan chan[3];
+ struct mbox_controller mbox;
+};
+
+static irqreturn_t mhu_rx_interrupt(int irq, void *p)
+{
+ struct mbox_chan *chan = p;
+ struct mhu_link *mlink = chan->con_priv;
+ u32 val;
+
+ val = readl_relaxed(mlink->rx_reg + INTR_STAT_OFS);
+ if (!val)
+ return IRQ_NONE;
+
+ mbox_chan_received_data(chan, (void *)&val);
+
+ writel_relaxed(val, mlink->rx_reg + INTR_CLR_OFS);
+
+ return IRQ_HANDLED;
+}
+
+static bool mhu_last_tx_done(struct mbox_chan *chan)
+{
+ struct mhu_link *mlink = chan->con_priv;
+ u32 val = readl_relaxed(mlink->tx_reg + INTR_STAT_OFS);
+
+ return (val == 0);
+}
+
+static int mhu_send_data(struct mbox_chan *chan, void *data)
+{
+ struct mhu_link *mlink = chan->con_priv;
+ u32 *arg = data;
+
+ if (!mhu_last_tx_done(chan)) {
+ dev_err(chan->mbox->dev, "Last TX(%d) pending!\n", mlink->irq);
+ return -EBUSY;
+ }
+
+ writel_relaxed(*arg, mlink->tx_reg + INTR_SET_OFS);
+
+ return 0;
+}
+
+static int mhu_startup(struct mbox_chan *chan)
+{
+ struct mhu_link *mlink = chan->con_priv;
+ u32 val;
+ int ret;
+
+ val = readl_relaxed(mlink->tx_reg + INTR_STAT_OFS);
+ writel_relaxed(val, mlink->tx_reg + INTR_CLR_OFS);
+
+ ret = request_irq(mlink->irq, mhu_rx_interrupt, 0, "mhu_link", chan);
+ if (ret) {
+ dev_err(chan->mbox->dev,
+ "Unable to aquire IRQ %d\n", mlink->irq);
+ return ret;
+ }
+
+ return 0;
+}
+
+static void mhu_shutdown(struct mbox_chan *chan)
+{
+ struct mhu_link *mlink = chan->con_priv;
+
+ free_irq(mlink->irq, chan);
+}
+
+static struct mbox_chan_ops mhu_ops = {
+ .send_data = mhu_send_data,
+ .startup = mhu_startup,
+ .shutdown = mhu_shutdown,
+ .last_tx_done = mhu_last_tx_done,
+};
+
+static int mhu_probe(struct amba_device *adev, const struct amba_id *id)
+{
+ int i, err;
+ struct arm_mhu *mhu;
+ struct device *dev = &adev->dev;
+ int mhu_reg[3] = {0x0, 0x20, 0x200};
+
+ err = amba_request_regions(adev, NULL);
+ if (err)
+ return err;
+
+ /* Allocate memory for device */
+ 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);
+ }
+
+ for (i = 0; i < 3; i++) {
+ mhu->chan[i].con_priv = &mhu->mlink[i];
+ mhu->mlink[i].irq = adev->irq[i];
+ mhu->mlink[i].rx_reg = mhu->base + mhu_reg[i];
+ mhu->mlink[i].tx_reg = mhu->mlink[i].rx_reg + 0x100;
+ }
+
+ mhu->mbox.dev = dev;
+ mhu->mbox.chans = &mhu->chan[0];
+ mhu->mbox.num_chans = 3;
+ mhu->mbox.ops = &mhu_ops;
+ mhu->mbox.txdone_irq = false;
+ mhu->mbox.txdone_poll = true;
+ mhu->mbox.txpoll_period = 10;
+
+ amba_set_drvdata(adev, mhu);
+
+ err = mbox_controller_register(&mhu->mbox);
+ if (err) {
+ dev_err(dev, "Failed to register mailboxes %d\n", err);
+ return err;
+ }
+
+ dev_info(dev, "ARM MHU Mailbox registered\n");
+ return 0;
+}
+
+static int mhu_remove(struct amba_device *adev)
+{
+ struct arm_mhu *mhu = amba_get_drvdata(adev);
+
+ mbox_controller_unregister(&mhu->mbox);
+
+ 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_driver = {
+ .drv = {
+ .name = "mhu",
+ },
+ .id_table = mhu_ids,
+ .probe = mhu_probe,
+ .remove = mhu_remove,
+};
+module_amba_driver(arm_mhu_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("ARM MHU Driver");
+MODULE_AUTHOR("Jassi Brar <jassisinghbrar at gmail.com>");
--
1.9.0
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