/* * 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");