diff options
Diffstat (limited to 'mailbox/arm_mhu.c')
| -rw-r--r-- | mailbox/arm_mhu.c | 263 |
1 files changed, 263 insertions, 0 deletions
diff --git a/mailbox/arm_mhu.c b/mailbox/arm_mhu.c new file mode 100644 index 0000000..42a8833 --- /dev/null +++ b/mailbox/arm_mhu.c @@ -0,0 +1,263 @@ +/* + * Copyright (C) 2013-2015 Fujitsu Semiconductor Ltd. + * Copyright (C) 2015 Linaro Ltd. + * Copyright (C) 2020 Arm Ltd. + * Author: Jassi Brar <jaswinder.singh@linaro.org> + * + * This program is free software and is provided to you under the terms of the + * GNU General Public License version 2 as published by the Free Software + * Foundation, and any use by you of this program is subject to the terms + * of such GNU licence. + * + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, you can access it online at + * http://www.gnu.org/licenses/gpl-2.0.html. + * + * SPDX-License-Identifier: GPL-2.0-only + */ + +#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> + +struct mhu_register_offsets { + uint8_t intr_stat_ofs; + uint8_t intr_set_ofs; + uint8_t intr_clr_ofs; +}; + +#define MHU_MAX_CHANS 3 +struct mhu_cfg { + uint32_t id; + uint8_t channels; + struct mhu_register_offsets offsets; + uint16_t tx_offset; + uint16_t rx_offset; + uint32_t channel_offsets[MHU_MAX_CHANS]; +}; + +struct mhu_link { + unsigned irq; + void __iomem *tx_reg; + void __iomem *rx_reg; + struct mhu_register_offsets *offsets; +}; + +#define MHU_LP_OFFSET 0x0 +#define MHU_HP_OFFSET 0x20 +#define MHU_SEC_OFFSET 0x200 +static struct mhu_cfg mhu_cfgs[] = { + { + /* MHUv1 */ + .id = 0x1bb098, + .channels = 3, + .offsets = { + .intr_stat_ofs = 0x0, + .intr_set_ofs = 0x8, + .intr_clr_ofs = 0x10, + }, + .tx_offset = 0x100, + .rx_offset = 0x0, + .channel_offsets = {MHU_LP_OFFSET, MHU_HP_OFFSET, MHU_SEC_OFFSET} + }, + { + /* MHU found on CoreLink SSE200 */ + .id = 0x0bb856, + .channels = 1, + .offsets = { + .intr_stat_ofs = 0x0, + .intr_set_ofs = 0x4, + .intr_clr_ofs = 0x8, + }, + .tx_offset = 0x0, + .rx_offset = 0x10, + .channel_offsets = {0} + } +}; + +struct arm_mhu { + void __iomem *base; + struct mhu_link mlink[MHU_MAX_CHANS]; + struct mbox_chan chan[MHU_MAX_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 + mlink->offsets->intr_stat_ofs); + if (!val) + return IRQ_NONE; + + mbox_chan_received_data(chan, (void *)&val); + + writel_relaxed(val, mlink->rx_reg + mlink->offsets->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 + mlink->offsets->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 + mlink->offsets->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 + mlink->offsets->intr_stat_ofs); + writel_relaxed(val, mlink->tx_reg + mlink->offsets->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; + struct mhu_cfg *cfg = NULL; + + /* 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 < ARRAY_SIZE(mhu_cfgs); i++) { + if ((mhu_cfgs[i].id & id->mask) == id->id) { + cfg = &mhu_cfgs[i]; + break; + } + } + + if (!cfg) { + dev_err(dev, "Failed to match id %x to configuration\n", id->id); + return -EINVAL; + } + + for (i = 0; i < cfg->channels; i++) { + mhu->chan[i].con_priv = &mhu->mlink[i]; + mhu->mlink[i].irq = adev->irq[i]; + mhu->mlink[i].rx_reg = mhu->base + cfg->channel_offsets[i] + + cfg->rx_offset; + mhu->mlink[i].tx_reg = mhu->base + cfg->channel_offsets[i] + + cfg->tx_offset; + mhu->mlink[i].offsets = &cfg->offsets; + } + + mhu->mbox.dev = dev; + mhu->mbox.chans = &mhu->chan[0]; + mhu->mbox.num_chans = cfg->channels; + 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, + }, + { + .id = 0x0bb856, + .mask = 0xffffff, + }, + { 0, 0 }, +}; +MODULE_DEVICE_TABLE(amba, mhu_ids); + +static struct amba_driver arm_mhu_driver = { + .drv = { + /* Change name from "mhu" to "mhu_v1" to avoid conflict with + * upstream version of kernel module. + */ + .name = "mhu_v1", + }, + .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>"); |