1 files changed, 205 insertions, 0 deletions

diff --git a/drivers/mailbox/platform_mhu.c b/drivers/mailbox/platform_mhu.c
new file mode 100644
index 000000000000..e13201a5cec6
--- /dev/null
+++ b/drivers/mailbox/platform_mhu.c
@@ -0,0 +1,205 @@
+/*
+ * Copyright (C) 2016 BayLibre SAS.
+ * Author: Neil Armstrong <narmstrong@baylibre.com>
+ * Synchronised with 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_SEC_OFFSET  0x0
+#define MHU_LP_OFFSET   0xc
+#define MHU_HP_OFFSET   0x18
+#define TX_REG_OFFSET   0x24
+
+#define MHU_CHANS       3
+
+struct platform_mhu_link {
+        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_SEC_OFFSET, 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>");