--- /dev/null
+/*
+ * Hisilicon's Hi6220 mailbox driver
+ *
+ * Copyright (c) 2015 Hisilicon Limited.
+ * Copyright (c) 2015 Linaro Limited.
+ *
+ * Author: Leo Yan <leo.yan@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/device.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kfifo.h>
+#include <linux/mailbox_controller.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#define MBOX_CHAN_MAX 32
+
+#define MBOX_TX 0x1
+
+/* Mailbox message length: 8 words */
+#define MBOX_MSG_LEN 8
+
+/* Mailbox Registers */
+#define MBOX_OFF(m) (0x40 * (m))
+#define MBOX_MODE_REG(m) (MBOX_OFF(m) + 0x0)
+#define MBOX_DATA_REG(m) (MBOX_OFF(m) + 0x4)
+
+#define MBOX_STATE_MASK (0xF << 4)
+#define MBOX_STATE_IDLE (0x1 << 4)
+#define MBOX_STATE_TX (0x2 << 4)
+#define MBOX_STATE_RX (0x4 << 4)
+#define MBOX_STATE_ACK (0x8 << 4)
+#define MBOX_ACK_CONFIG_MASK (0x1 << 0)
+#define MBOX_ACK_AUTOMATIC (0x1 << 0)
+#define MBOX_ACK_IRQ (0x0 << 0)
+
+/* IPC registers */
+#define ACK_INT_RAW_REG(i) ((i) + 0x400)
+#define ACK_INT_MSK_REG(i) ((i) + 0x404)
+#define ACK_INT_STAT_REG(i) ((i) + 0x408)
+#define ACK_INT_CLR_REG(i) ((i) + 0x40c)
+#define ACK_INT_ENA_REG(i) ((i) + 0x500)
+#define ACK_INT_DIS_REG(i) ((i) + 0x504)
+#define DST_INT_RAW_REG(i) ((i) + 0x420)
+
+
+struct hi6220_mbox_chan {
+
+ /*
+ * Description for channel's hardware info:
+ * - direction: tx or rx
+ * - dst irq: peer core's irq number
+ * - ack irq: local irq number
+ * - slot number
+ */
+ unsigned int dir, dst_irq, ack_irq;
+ unsigned int slot;
+
+ struct hi6220_mbox *parent;
+};
+
+struct hi6220_mbox {
+ struct device *dev;
+
+ int irq;
+
+ /* flag of enabling tx's irq mode */
+ bool tx_irq_mode;
+
+ /* region for ipc event */
+ void __iomem *ipc;
+
+ /* region for mailbox */
+ void __iomem *base;
+
+ unsigned int chan_num;
+ struct hi6220_mbox_chan *mchan;
+
+ void *irq_map_chan[MBOX_CHAN_MAX];
+ struct mbox_chan *chan;
+ struct mbox_controller controller;
+};
+
+static void mbox_set_state(struct hi6220_mbox *mbox,
+ unsigned int slot, u32 val)
+{
+ u32 status;
+
+ status = readl(mbox->base + MBOX_MODE_REG(slot));
+ status = (status & ~MBOX_STATE_MASK) | val;
+ writel(status, mbox->base + MBOX_MODE_REG(slot));
+}
+
+static void mbox_set_mode(struct hi6220_mbox *mbox,
+ unsigned int slot, u32 val)
+{
+ u32 mode;
+
+ mode = readl(mbox->base + MBOX_MODE_REG(slot));
+ mode = (mode & ~MBOX_ACK_CONFIG_MASK) | val;
+ writel(mode, mbox->base + MBOX_MODE_REG(slot));
+}
+
+static bool hi6220_mbox_last_tx_done(struct mbox_chan *chan)
+{
+ struct hi6220_mbox_chan *mchan = chan->con_priv;
+ struct hi6220_mbox *mbox = mchan->parent;
+ u32 state;
+
+ /* Only set idle state for polling mode */
+ BUG_ON(mbox->tx_irq_mode);
+
+ state = readl(mbox->base + MBOX_MODE_REG(mchan->slot));
+ return ((state & MBOX_STATE_MASK) == MBOX_STATE_IDLE);
+}
+
+static int hi6220_mbox_send_data(struct mbox_chan *chan, void *msg)
+{
+ struct hi6220_mbox_chan *mchan = chan->con_priv;
+ struct hi6220_mbox *mbox = mchan->parent;
+ unsigned int slot = mchan->slot;
+ u32 *buf = msg;
+ int i;
+
+ /* indicate as a TX channel */
+ mchan->dir = MBOX_TX;
+
+ mbox_set_state(mbox, slot, MBOX_STATE_TX);
+
+ if (mbox->tx_irq_mode)
+ mbox_set_mode(mbox, slot, MBOX_ACK_IRQ);
+ else
+ mbox_set_mode(mbox, slot, MBOX_ACK_AUTOMATIC);
+
+ for (i = 0; i < MBOX_MSG_LEN; i++)
+ writel(buf[i], mbox->base + MBOX_DATA_REG(slot) + i * 4);
+
+ /* trigger remote request */
+ writel(BIT(mchan->dst_irq), DST_INT_RAW_REG(mbox->ipc));
+ return 0;
+}
+
+static irqreturn_t hi6220_mbox_interrupt(int irq, void *p)
+{
+ struct hi6220_mbox *mbox = p;
+ struct hi6220_mbox_chan *mchan;
+ struct mbox_chan *chan;
+ unsigned int state, intr_bit, i;
+ u32 msg[MBOX_MSG_LEN];
+
+ state = readl(ACK_INT_STAT_REG(mbox->ipc));
+ if (!state) {
+ dev_warn(mbox->dev, "%s: spurious interrupt\n",
+ __func__);
+ return IRQ_HANDLED;
+ }
+
+ while (state) {
+ intr_bit = __ffs(state);
+ state &= (state - 1);
+
+ chan = mbox->irq_map_chan[intr_bit];
+ if (!chan) {
+ dev_warn(mbox->dev, "%s: unexpected irq vector %d\n",
+ __func__, intr_bit);
+ continue;
+ }
+
+ mchan = chan->con_priv;
+ if (mchan->dir == MBOX_TX)
+ mbox_chan_txdone(chan, 0);
+ else {
+ for (i = 0; i < MBOX_MSG_LEN; i++)
+ msg[i] = readl(mbox->base +
+ MBOX_DATA_REG(mchan->slot) + i * 4);
+
+ mbox_chan_received_data(chan, (void *)msg);
+ }
+
+ /* clear IRQ source */
+ writel(BIT(mchan->ack_irq), ACK_INT_CLR_REG(mbox->ipc));
+ mbox_set_state(mbox, mchan->slot, MBOX_STATE_IDLE);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static int hi6220_mbox_startup(struct mbox_chan *chan)
+{
+ struct hi6220_mbox_chan *mchan = chan->con_priv;
+ struct hi6220_mbox *mbox = mchan->parent;
+
+ mchan->dir = 0;
+
+ /* enable interrupt */
+ writel(BIT(mchan->ack_irq), ACK_INT_ENA_REG(mbox->ipc));
+ return 0;
+}
+
+static void hi6220_mbox_shutdown(struct mbox_chan *chan)
+{
+ struct hi6220_mbox_chan *mchan = chan->con_priv;
+ struct hi6220_mbox *mbox = mchan->parent;
+
+ /* disable interrupt */
+ writel(BIT(mchan->ack_irq), ACK_INT_DIS_REG(mbox->ipc));
+ mbox->irq_map_chan[mchan->ack_irq] = NULL;
+}
+
+static struct mbox_chan_ops hi6220_mbox_ops = {
+ .send_data = hi6220_mbox_send_data,
+ .startup = hi6220_mbox_startup,
+ .shutdown = hi6220_mbox_shutdown,
+ .last_tx_done = hi6220_mbox_last_tx_done,
+};
+
+static struct mbox_chan *hi6220_mbox_xlate(struct mbox_controller *controller,
+ const struct of_phandle_args *spec)
+{
+ struct hi6220_mbox *mbox = dev_get_drvdata(controller->dev);
+ struct hi6220_mbox_chan *mchan;
+ struct mbox_chan *chan;
+ unsigned int i = spec->args[0];
+ unsigned int dst_irq = spec->args[1];
+ unsigned int ack_irq = spec->args[2];
+
+ /* Bounds checking */
+ if (i >= mbox->chan_num || dst_irq >= mbox->chan_num ||
+ ack_irq >= mbox->chan_num) {
+ dev_err(mbox->dev,
+ "Invalid channel idx %d dst_irq %d ack_irq %d\n",
+ i, dst_irq, ack_irq);
+ return ERR_PTR(-EINVAL);
+ }
+
+ /* Is requested channel free? */
+ chan = &mbox->chan[i];
+ if (mbox->irq_map_chan[ack_irq] == (void *)chan) {
+ dev_err(mbox->dev, "Channel in use\n");
+ return ERR_PTR(-EBUSY);
+ }
+
+ mchan = chan->con_priv;
+ mchan->dst_irq = dst_irq;
+ mchan->ack_irq = ack_irq;
+
+ mbox->irq_map_chan[ack_irq] = (void *)chan;
+ return chan;
+}
+
+static const struct of_device_id hi6220_mbox_of_match[] = {
+ { .compatible = "hisilicon,hi6220-mbox", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, hi6220_mbox_of_match);
+
+static int hi6220_mbox_probe(struct platform_device *pdev)
+{
+ struct device_node *node = pdev->dev.of_node;
+ struct device *dev = &pdev->dev;
+ struct hi6220_mbox *mbox;
+ struct resource *res;
+ int i, err;
+
+ mbox = devm_kzalloc(dev, sizeof(*mbox), GFP_KERNEL);
+ if (!mbox)
+ return -ENOMEM;
+
+ mbox->dev = dev;
+ mbox->chan_num = MBOX_CHAN_MAX;
+ mbox->mchan = devm_kzalloc(dev,
+ mbox->chan_num * sizeof(*mbox->mchan), GFP_KERNEL);
+ if (!mbox->mchan)
+ return -ENOMEM;
+
+ mbox->chan = devm_kzalloc(dev,
+ mbox->chan_num * sizeof(*mbox->chan), GFP_KERNEL);
+ if (!mbox->chan)
+ return -ENOMEM;
+
+ mbox->irq = platform_get_irq(pdev, 0);
+ if (mbox->irq < 0)
+ return mbox->irq;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ mbox->ipc = devm_ioremap_resource(dev, res);
+ if (IS_ERR(mbox->ipc)) {
+ dev_err(dev, "ioremap ipc failed\n");
+ return PTR_ERR(mbox->ipc);
+ }
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+ mbox->base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(mbox->base)) {
+ dev_err(dev, "ioremap buffer failed\n");
+ return PTR_ERR(mbox->base);
+ }
+
+ err = devm_request_irq(dev, mbox->irq, hi6220_mbox_interrupt, 0,
+ dev_name(dev), mbox);
+ if (err) {
+ dev_err(dev, "Failed to register a mailbox IRQ handler: %d\n",
+ err);
+ return -ENODEV;
+ }
+
+ mbox->controller.dev = dev;
+ mbox->controller.chans = &mbox->chan[0];
+ mbox->controller.num_chans = mbox->chan_num;
+ mbox->controller.ops = &hi6220_mbox_ops;
+ mbox->controller.of_xlate = hi6220_mbox_xlate;
+
+ for (i = 0; i < mbox->chan_num; i++) {
+ mbox->chan[i].con_priv = &mbox->mchan[i];
+ mbox->irq_map_chan[i] = NULL;
+
+ mbox->mchan[i].parent = mbox;
+ mbox->mchan[i].slot = i;
+ }
+
+ /* mask and clear all interrupt vectors */
+ writel(0x0, ACK_INT_MSK_REG(mbox->ipc));
+ writel(~0x0, ACK_INT_CLR_REG(mbox->ipc));
+
+ /* use interrupt for tx's ack */
+ if (of_find_property(node, "hi6220,mbox-tx-noirq", NULL))
+ mbox->tx_irq_mode = false;
+ else
+ mbox->tx_irq_mode = true;
+
+ if (mbox->tx_irq_mode)
+ mbox->controller.txdone_irq = true;
+ else {
+ mbox->controller.txdone_poll = true;
+ mbox->controller.txpoll_period = 5;
+ }
+
+ err = mbox_controller_register(&mbox->controller);
+ if (err) {
+ dev_err(dev, "Failed to register mailbox %d\n", err);
+ return err;
+ }
+
+ platform_set_drvdata(pdev, mbox);
+ dev_info(dev, "Mailbox enabled\n");
+ return 0;
+}
+
+static int hi6220_mbox_remove(struct platform_device *pdev)
+{
+ struct hi6220_mbox *mbox = platform_get_drvdata(pdev);
+
+ mbox_controller_unregister(&mbox->controller);
+ return 0;
+}
+
+static struct platform_driver hi6220_mbox_driver = {
+ .driver = {
+ .name = "hi6220-mbox",
+ .owner = THIS_MODULE,
+ .of_match_table = hi6220_mbox_of_match,
+ },
+ .probe = hi6220_mbox_probe,
+ .remove = hi6220_mbox_remove,
+};
+
+static int __init hi6220_mbox_init(void)
+{
+ return platform_driver_register(&hi6220_mbox_driver);
+}
+core_initcall(hi6220_mbox_init);
+
+static void __exit hi6220_mbox_exit(void)
+{
+ platform_driver_unregister(&hi6220_mbox_driver);
+}
+module_exit(hi6220_mbox_exit);
+
+MODULE_AUTHOR("Leo Yan <leo.yan@linaro.org>");
+MODULE_DESCRIPTION("Hi6220 mailbox driver");
+MODULE_LICENSE("GPL v2");
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