[PATCH v3 2/3] mailbox: Add support for Hi3660 mailbox
Leo Yan
leo.yan at linaro.org
Mon Dec 4 21:13:40 PST 2017
On Tue, Dec 05, 2017 at 08:58:05AM +0530, Jassi Brar wrote:
> On Fri, Nov 17, 2017 at 2:54 PM, Xu YiPing <xuyiping at hisilicon.com> wrote:
> > From: Kaihua Zhong <zhongkaihua at huawei.com>
> >
> > Hi3660 mailbox controller is used to send message within multiple
> > processors, MCU, HIFI, etc. It supports 32 mailbox channels and every
> > channel can only be used for single transferring direction. Once the
> > channel is enabled, it needs to specify the destination interrupt and
> > acknowledge interrupt, these two interrupt vectors are used to create
> > the connection between the mailbox and interrupt controllers.
> >
> > The data transferring supports two modes, one is named as "automatic
> > acknowledge" mode so after send message the kernel doesn't need to wait
> > for acknowledge from remote and directly return; there have another mode
> > is to rely on handling interrupt for acknowledge.
> >
> > This commit is for initial version driver, which only supports
> > "automatic acknowledge" mode to support CPU clock, which is the only
> > one consumer to use mailbox and has been verified. Later may enhance
> > this driver for interrupt mode (e.g. for supporting HIFI).
> >
> > Signed-off-by: Leo Yan <leo.yan at linaro.org>
> > Signed-off-by: Ruyi Wang <wangruyi at huawei.com>
> > Signed-off-by: Kaihua Zhong <zhongkaihua at huawei.com>
> > ---
> > drivers/mailbox/Kconfig | 8 +
> > drivers/mailbox/Makefile | 2 +
> > drivers/mailbox/hi3660-mailbox.c | 322 +++++++++++++++++++++++++++++++++++++++
> > 3 files changed, 332 insertions(+)
> > create mode 100644 drivers/mailbox/hi3660-mailbox.c
> >
> > diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
> > index c5731e5..4b5d6e9 100644
> > --- a/drivers/mailbox/Kconfig
> > +++ b/drivers/mailbox/Kconfig
> > @@ -108,6 +108,14 @@ config TI_MESSAGE_MANAGER
> > multiple processors within the SoC. Select this driver if your
> > platform has support for the hardware block.
> >
> > +config HI3660_MBOX
> > + tristate "Hi3660 Mailbox"
> > + depends on ARCH_HISI && OF
> > + help
> > + An implementation of the hi3660 mailbox. It is used to send message
> > + between application processors and other processors/MCU/DSP. Select
> > + Y here if you want to use Hi3660 mailbox controller.
> > +
> > config HI6220_MBOX
> > tristate "Hi6220 Mailbox"
> > depends on ARCH_HISI
> > diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
> > index d54e412..7d1bd51 100644
> > --- a/drivers/mailbox/Makefile
> > +++ b/drivers/mailbox/Makefile
> > @@ -26,6 +26,8 @@ obj-$(CONFIG_TI_MESSAGE_MANAGER) += ti-msgmgr.o
> >
> > obj-$(CONFIG_XGENE_SLIMPRO_MBOX) += mailbox-xgene-slimpro.o
> >
> > +obj-$(CONFIG_HI3660_MBOX) += hi3660-mailbox.o
> > +
> > obj-$(CONFIG_HI6220_MBOX) += hi6220-mailbox.o
> >
> > obj-$(CONFIG_BCM_PDC_MBOX) += bcm-pdc-mailbox.o
> > diff --git a/drivers/mailbox/hi3660-mailbox.c b/drivers/mailbox/hi3660-mailbox.c
> > new file mode 100644
> > index 0000000..ba80834
> > --- /dev/null
> > +++ b/drivers/mailbox/hi3660-mailbox.c
> > @@ -0,0 +1,322 @@
> > +/*
> > + * Hisilicon's Hi3660 mailbox controller driver
> > + *
> > + * Copyright (c) 2017 Hisilicon Limited.
> > + * Copyright (c) 2017 Linaro Limited.
> > + *
> > + * Author: Leo Yan <leo.yan at 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.
> > + *
> >
> We now use SPDX licence
Thanks for quick response, Jassi.
Will change to SPDX licence fashion.
> > + */
> > +
> > +#include <linux/bitops.h>
> > +#include <linux/delay.h>
> > +#include <linux/device.h>
> > +#include <linux/err.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/io.h>
> > +#include <linux/iopoll.h>
> > +#include <linux/mailbox_controller.h>
> > +#include <linux/module.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/slab.h>
> > +
> > +#include "mailbox.h"
> > +
> > +#define MBOX_CHAN_MAX 32
> > +
> > +#define MBOX_RX (0x0)
> > +#define MBOX_TX (0x1)
> > +
> > +#define MBOX_BASE(mbox, ch) ((mbox)->base + ((ch) * 0x40))
> > +#define MBOX_SRC_REG (0x00)
> > +#define MBOX_DST_REG (0x04)
> > +#define MBOX_DCLR_REG (0x08)
> > +#define MBOX_DSTAT_REG (0x0c)
> > +#define MBOX_MODE_REG (0x10)
> > +#define MBOX_IMASK_REG (0x14)
> > +#define MBOX_ICLR_REG (0x18)
> > +#define MBOX_SEND_REG (0x1c)
> > +#define MBOX_DATA_REG (0x20)
> > +
> > +#define MBOX_IPC_LOCK_REG (0xa00)
> > +#define MBOX_IPC_UNLOCK (0x1acce551)
> > +
> > +#define MBOX_AUTOMATIC_ACK (1)
> > +
> Please, no brackets around numbers.
Sure, will remove brackets.
> > +#define MBOX_STATE_IDLE BIT(4)
> > +#define MBOX_STATE_ACK BIT(7)
> > +
> > +#define MBOX_MSG_LEN 8
> > +
> > +/**
> > + * Hi3660 mailbox channel device data
> > + *
> > + * A channel can be used for TX or RX, it can trigger remote
> > + * processor interrupt to notify remote processor and can receive
> > + * interrupt if has incoming message.
> > + *
> > + * @dst_irq: Interrupt vector for remote processor
> > + * @ack_irq: Interrupt vector for local processor
> > + */
> > +struct hi3660_mbox_dev {
> >
> Better than dev, maybe hi3660_chan_info ?
>
> > + unsigned int dst_irq;
> > + unsigned int ack_irq;
> > +};
> > +
> > +/**
> > + * Hi3660 mailbox controller data
> > + *
> > + * Mailbox controller includes 32 channels and can allocate
> > + * channel for message transferring.
> > + *
> > + * @dev: Device to which it is attached
> > + * @base: Base address of the register mapping region
> > + * @chan: Representation of channels in mailbox controller
> > + * @mdev: Representation of channel device data
> > + * @controller: Representation of a communication channel controller
> > + */
> > +struct hi3660_mbox {
> > + struct device *dev;
> > + void __iomem *base;
> > + struct mbox_chan chan[MBOX_CHAN_MAX];
> > + struct hi3660_mbox_dev mdev[MBOX_CHAN_MAX];
> >
> Maybe mchan, instead of mdev.
Will refactor structure name.
> > + struct mbox_controller controller;
> > +};
> > +
> > +static inline struct hi3660_mbox *to_hi3660_mbox(struct mbox_controller *mbox)
> > +{
> > + return container_of(mbox, struct hi3660_mbox, controller);
> > +}
> > +
> > +static int hi3660_mbox_check_state(struct mbox_chan *chan)
> > +{
> > + unsigned long ch = (unsigned long)chan->con_priv;
> > + struct hi3660_mbox *mbox = to_hi3660_mbox(chan->mbox);
> > + struct hi3660_mbox_dev *mdev = &mbox->mdev[ch];
> > + void __iomem *base = MBOX_BASE(mbox, ch);
> > + unsigned long val;
> > + unsigned int state, ret;
> > +
> > + /* Mailbox is idle so directly bail out */
> > + state = readl_relaxed(base + MBOX_MODE_REG);
> > + if (state & MBOX_STATE_IDLE)
> > + return 0;
> > +
> > + /* Wait for acknowledge from remote */
> > + ret = readx_poll_timeout_atomic(readl_relaxed, base + MBOX_MODE_REG,
> > + val, (val & MBOX_STATE_ACK), 1000, 300000);
> > + if (ret) {
> > + dev_err(mbox->dev, "%s: timeout for receiving ack\n", __func__);
> > + return ret;
> > + }
> > +
> > + /* Ensure channel is released */
> > + writel_relaxed(0xffffffff, base + MBOX_IMASK_REG);
> > + writel_relaxed(BIT(mdev->ack_irq), base + MBOX_SRC_REG);
> > +
> > + return 0;
> > +}
> > +
> > +static int hi3660_mbox_unlock(struct mbox_chan *chan)
> > +{
> > + struct hi3660_mbox *mbox = to_hi3660_mbox(chan->mbox);
> > + unsigned int val, retry = 3;
> > +
> > + do {
> > + writel_relaxed(MBOX_IPC_UNLOCK, mbox->base + MBOX_IPC_LOCK_REG);
> > +
> > + val = readl_relaxed(mbox->base + MBOX_IPC_LOCK_REG);
> > + if (!val)
> > + break;
> > +
> > + udelay(10);
> > + } while (retry--);
> > +
> > + return (!val) ? 0 : -ETIMEDOUT;
> > +}
> > +
> > +static int hi3660_mbox_acquire_channel(struct mbox_chan *chan)
> > +{
> > + unsigned long ch = (unsigned long)chan->con_priv;
> > + struct hi3660_mbox *mbox = to_hi3660_mbox(chan->mbox);
> > + struct hi3660_mbox_dev *mdev = &mbox->mdev[ch];
> > + void __iomem *base = MBOX_BASE(mbox, ch);
> > + unsigned int val, retry;
> > +
> > + for (retry = 10; retry; retry--) {
> > + /* Check if channel has been acquired */
> > + if (readl_relaxed(base + MBOX_MODE_REG) & MBOX_STATE_IDLE) {
> > + writel_relaxed(BIT(mdev->ack_irq), base + MBOX_SRC_REG);
> > + val = readl_relaxed(base + MBOX_SRC_REG);
> > + if (val & BIT(mdev->ack_irq))
> > + break;
> > + }
> > + }
> > +
> > + return retry ? 0 : -ETIMEDOUT;
> > +}
> > +
> > +static int hi3660_mbox_send(struct mbox_chan *chan, u32 *msg)
> > +{
> > + unsigned long ch = (unsigned long)chan->con_priv;
> > + struct hi3660_mbox *mbox = to_hi3660_mbox(chan->mbox);
> > + struct hi3660_mbox_dev *mdev = &mbox->mdev[ch];
> > + void __iomem *base = MBOX_BASE(mbox, ch);
> > + unsigned int i;
> > +
> > + /* Clear mask for destination interrupt */
> > + writel_relaxed(~BIT(mdev->dst_irq), base + MBOX_IMASK_REG);
> > +
> > + /* Config destination for interrupt vector */
> > + writel_relaxed(BIT(mdev->dst_irq), base + MBOX_DST_REG);
> > +
> > + /* Automatic acknowledge mode */
> > + writel_relaxed(MBOX_AUTOMATIC_ACK, base + MBOX_MODE_REG);
> > +
> > + /* Fill message data */
> > + for (i = 0; i < MBOX_MSG_LEN; i++)
> > + writel_relaxed(msg[i], base + MBOX_DATA_REG + i * 4);
> > +
> > + /* Trigger data transferring */
> > + writel_relaxed(BIT(mdev->ack_irq), base + MBOX_SEND_REG);
> > + return 0;
> > +}
> > +
> > +static int hi3660_mbox_send_data(struct mbox_chan *chan, void *msg)
> > +{
> > + struct hi3660_mbox *mbox = to_hi3660_mbox(chan->mbox);
> > + int err;
> > +
> > + err = hi3660_mbox_check_state(chan);
> > + if (err) {
> > + dev_err(mbox->dev, "checking state failed\n");
> > + return err;
> > + }
> > +
> > + err = hi3660_mbox_unlock(chan);
> > + if (err) {
> > + dev_err(mbox->dev, "unlocking mailbox failed\n");
> > + return err;
> > + }
> > +
> > + err = hi3660_mbox_acquire_channel(chan);
> > + if (err) {
> > + dev_err(mbox->dev, "acquiring channel failed\n");
> > + return err;
> > + }
> > +
> Please remember .send_data() is called with irqs disabled spinlock
> All these polling functions hurt. Please move the above three checks
> in last_tx_done()
I have tried to move these three checks in last_tx_done(), since these
three functions tightly couple with mailbox state machine, so I failed
to move them to last_tx_done().
Anyway, I will try to move them to last_tx_done() for next version
patch.
Thanks,
Leo Yan
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