[PATCH 1/3] mailbox: Add Platform Message-Handling-Unit variant driver

Neil Armstrong
2016-08-09T08:52:15Z

Add Message-Handling-Unit driver for platform variants as mailbox controller.
Actually, only the Amlogic Meson GXBB SoC MHU is supported.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
---
drivers/mailbox/Kconfig | 10 ++
drivers/mailbox/Makefile | 2 +
drivers/mailbox/platform_mhu.c | 203 +++++++++++++++++++++++++++++++++++++++++
3 files changed, 215 insertions(+)
create mode 100644 drivers/mailbox/platform_mhu.c

diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
index 97c3729..4cc93c6 100644
--- a/drivers/mailbox/Kconfig
+++ b/drivers/mailbox/Kconfig
@@ -15,6 +15,16 @@ config ARM_MHU
The controller has 3 mailbox channels, the last of which can be
used in Secure mode only.

+config PLATFORM_MHU
+ tristate "Platform MHU Mailbox"
+ depends on OF
+ depends on HAS_IOMEM
+ help
+ Say Y here if you want to build a platform specific variant MHU
+ controller driver.
+ The controller has a maximum of 3 mailbox channels, the last of
+ which can be used in Secure mode only.
+
config PL320_MBOX
bool "ARM PL320 Mailbox"
depends on ARM_AMBA
diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
index 66c38e3..ace6fed 100644
--- a/drivers/mailbox/Makefile
+++ b/drivers/mailbox/Makefile
@@ -6,6 +6,8 @@ obj-$(CONFIG_MAILBOX_TEST) += mailbox-test.o

obj-$(CONFIG_ARM_MHU) += arm_mhu.o

+obj-$(CONFIG_PLATFORM_MHU) += platform_mhu.o
+
obj-$(CONFIG_PL320_MBOX) += pl320-ipc.o

obj-$(CONFIG_OMAP2PLUS_MBOX) += omap-mailbox.o
diff --git a/drivers/mailbox/platform_mhu.c b/drivers/mailbox/platform_mhu.c
new file mode 100644
index 0000000..d657a50
--- /dev/null
+++ b/drivers/mailbox/platform_mhu.c
@@ -0,0 +1,203 @@
+/*
+ * Copyright (C) 2016 BayLibre SAS.
+ * Author: Neil Armstrong <narmstrong@baylibre.com>
+ * Heavily based on arm_mhu.c from :
+ * Copyright (C) 2013-2015 Fujitsu Semiconductor Ltd.
+ * Copyright (C) 2015 Linaro Ltd.
+ * Author: Jassi Brar <jaswinder.singh@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/platform_device.h>
+#include <linux/mailbox_controller.h>
+
+#define INTR_SET_OFS 0x0
+#define INTR_STAT_OFS 0x4
+#define INTR_CLR_OFS 0x8
+
+#define MHU_LP_OFFSET 0x10
+#define MHU_HP_OFFSET 0x1c
+
+#define TX_REG_OFFSET 0x24
+
+#define MHU_CHANS 2
+
+struct platform_mhu_link {
+ unsigned int irq;
+ void __iomem *tx_reg;
+ void __iomem *rx_reg;
+};
+
+struct platform_mhu {
+ void __iomem *base;
+ struct platform_mhu_link mlink[MHU_CHANS];
+ struct mbox_chan chan[MHU_CHANS];
+ struct mbox_controller mbox;
+};
+
+static irqreturn_t platform_mhu_rx_interrupt(int irq, void *p)
+{
+ struct mbox_chan *chan = p;
+ struct platform_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 platform_mhu_last_tx_done(struct mbox_chan *chan)
+{
+ struct platform_mhu_link *mlink = chan->con_priv;
+ u32 val = readl_relaxed(mlink->tx_reg + INTR_STAT_OFS);
+
+ return (val == 0);
+}
+
+static int platform_mhu_send_data(struct mbox_chan *chan, void *data)
+{
+ struct platform_mhu_link *mlink = chan->con_priv;
+ u32 *arg = data;
+
+ writel_relaxed(*arg, mlink->tx_reg + INTR_SET_OFS);
+
+ return 0;
+}
+
+static int platform_mhu_startup(struct mbox_chan *chan)
+{
+ struct platform_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, platform_mhu_rx_interrupt,
+ IRQF_SHARED, "platform_mhu_link", chan);
+ if (ret) {
+ dev_err(chan->mbox->dev,
+ "Unable to acquire IRQ %d\n", mlink->irq);
+ return ret;
+ }
+
+ return 0;
+}
+
+static void platform_mhu_shutdown(struct mbox_chan *chan)
+{
+ struct platform_mhu_link *mlink = chan->con_priv;
+
+ free_irq(mlink->irq, chan);
+}
+
+static const struct mbox_chan_ops platform_mhu_ops = {
+ .send_data = platform_mhu_send_data,
+ .startup = platform_mhu_startup,
+ .shutdown = platform_mhu_shutdown,
+ .last_tx_done = platform_mhu_last_tx_done,
+};
+
+static int platform_mhu_probe(struct platform_device *pdev)
+{
+ int i, err;
+ struct platform_mhu *mhu;
+ struct device *dev = &pdev->dev;
+ struct resource *res;
+ int platform_mhu_reg[MHU_CHANS] = {MHU_LP_OFFSET, MHU_HP_OFFSET};
+
+ /* Allocate memory for device */
+ mhu = devm_kzalloc(dev, sizeof(*mhu), GFP_KERNEL);
+ if (!mhu)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ mhu->base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(mhu->base)) {
+ dev_err(dev, "ioremap failed\n");
+ return PTR_ERR(mhu->base);
+ }
+
+ for (i = 0; i < MHU_CHANS; i++) {
+ mhu->chan[i].con_priv = &mhu->mlink[i];
+ mhu->mlink[i].irq = platform_get_irq(pdev, i);
+ if (mhu->mlink[i].irq < 0) {
+ dev_err(dev, "failed to get irq%d\n", i);
+ return mhu->mlink[i].irq;
+ }
+ mhu->mlink[i].rx_reg = mhu->base + platform_mhu_reg[i];
+ mhu->mlink[i].tx_reg = mhu->mlink[i].rx_reg + TX_REG_OFFSET;
+ }
+
+ mhu->mbox.dev = dev;
+ mhu->mbox.chans = &mhu->chan[0];
+ mhu->mbox.num_chans = MHU_CHANS;
+ mhu->mbox.ops = &platform_mhu_ops;
+ mhu->mbox.txdone_irq = false;
+ mhu->mbox.txdone_poll = true;
+ mhu->mbox.txpoll_period = 1;
+
+ platform_set_drvdata(pdev, mhu);
+
+ err = mbox_controller_register(&mhu->mbox);
+ if (err) {
+ dev_err(dev, "Failed to register mailboxes %d\n", err);
+ return err;
+ }
+
+ dev_info(dev, "Platform MHU Mailbox registered\n");
+ return 0;
+}
+
+static int platform_mhu_remove(struct platform_device *pdev)
+{
+ struct platform_mhu *mhu = platform_get_drvdata(pdev);
+
+ mbox_controller_unregister(&mhu->mbox);
+
+ return 0;
+}
+
+static const struct of_device_id platform_mhu_dt_ids[] = {
+ { .compatible = "amlogic,meson-gxbb-mhu", },
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, platform_mhu_dt_ids);
+
+static struct platform_driver platform_mhu_driver = {
+ .probe = platform_mhu_probe,
+ .remove = platform_mhu_remove,
+ .driver = {
+ .name = "platform-mhu",
+ .of_match_table = platform_mhu_dt_ids,
+ },
+};
+
+module_platform_driver(platform_mhu_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:platform-mhu");
+MODULE_DESCRIPTION("Platform MHU Driver");
+MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
--
2.7.0