--- /dev/null
+/*
+ * 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>");
projects / cascardo / linux.git / commitdiff