/* * 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/amba/bus.h> #include <linux/mailbox_controller.h> #define INTR_STAT_OFS 0x0 #define INTR_SET_OFS 0x8 #define INTR_CLR_OFS 0x10 #define MHU_LP_OFFSET 0x0 #define MHU_HP_OFFSET 0x20 #define MHU_SEC_OFFSET 0x200 #define TX_REG_OFFSET 0x100 #define MHU_CHANS 3 struct mhu_link { unsigned irq; void __iomem *tx_reg; void __iomem *rx_reg; }; struct arm_mhu { void __iomem *base; struct mhu_link mlink[MHU_CHANS]; struct mbox_chan chan[MHU_CHANS]; struct mbox_controller mbox; }; static irqreturn_t mhu_rx_interrupt(int irq, void *p) { struct mbox_chan *chan = p; struct 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 mhu_last_tx_done(struct mbox_chan *chan) { struct mhu_link *mlink = chan->con_priv; u32 val = readl_relaxed(mlink->tx_reg + INTR_STAT_OFS); return (val == 0); } static int mhu_send_data(struct mbox_chan *chan, void *data) { struct mhu_link *mlink = chan->con_priv; u32 *arg = data; writel_relaxed(*arg, mlink->tx_reg + INTR_SET_OFS); return 0; } static int mhu_startup(struct mbox_chan *chan) { struct 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, mhu_rx_interrupt, IRQF_SHARED, "mhu_link", chan); if (ret) { dev_err(chan->mbox->dev, "Unable to acquire IRQ %d\n", mlink->irq); return ret; } return 0; } static void mhu_shutdown(struct mbox_chan *chan) { struct mhu_link *mlink = chan->con_priv; free_irq(mlink->irq, chan); } static const struct mbox_chan_ops mhu_ops = { .send_data = mhu_send_data, .startup = mhu_startup, .shutdown = mhu_shutdown, .last_tx_done = mhu_last_tx_done, }; static int mhu_probe(struct amba_device *adev, const struct amba_id *id) { int i, err; struct arm_mhu *mhu; struct device *dev = &adev->dev; int mhu_reg[MHU_CHANS] = {MHU_LP_OFFSET, MHU_HP_OFFSET, MHU_SEC_OFFSET}; /* Allocate memory for device */ mhu = devm_kzalloc(dev, sizeof(*mhu), GFP_KERNEL); if (!mhu) return -ENOMEM; mhu->base = devm_ioremap_resource(dev, &adev->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 = adev->irq[i]; mhu->mlink[i].rx_reg = mhu->base + 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 = &mhu_ops; mhu->mbox.txdone_irq = false; mhu->mbox.txdone_poll = true; mhu->mbox.txpoll_period = 1; amba_set_drvdata(adev, mhu); err = mbox_controller_register(&mhu->mbox); if (err) { dev_err(dev, "Failed to register mailboxes %d\n", err); return err; } dev_info(dev, "ARM MHU Mailbox registered\n"); return 0; } static int mhu_remove(struct amba_device *adev) { struct arm_mhu *mhu = amba_get_drvdata(adev); mbox_controller_unregister(&mhu->mbox); return 0; } static struct amba_id mhu_ids[] = { { .id = 0x1bb098, .mask = 0xffffff, }, { 0, 0 }, }; MODULE_DEVICE_TABLE(amba, mhu_ids); static struct amba_driver arm_mhu_driver = { .drv = { .name = "mhu", }, .id_table = mhu_ids, .probe = mhu_probe, .remove = mhu_remove, }; module_amba_driver(arm_mhu_driver); MODULE_LICENSE("GPL v2"); MODULE_DESCRIPTION("ARM MHU Driver"); MODULE_AUTHOR("Jassi Brar <jassisinghbrar@gmail.com>");