[RFC,v2,1/9] mailbox: Add Amlogic Meson Message-Handling-Unit
diff mbox

Message ID 1466503374-28841-2-git-send-email-narmstrong@baylibre.com
State RFC
Headers show

Commit Message

Neil Armstrong June 21, 2016, 10:02 a.m. UTC
Add Amlogic Meson SoCs Message-Handling-Unit as mailbox controller
with 2 independent channels/links to communicate with a remote processor.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
---
 drivers/mailbox/Makefile    |   2 +
 drivers/mailbox/meson_mhu.c | 199 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 201 insertions(+)
 create mode 100644 drivers/mailbox/meson_mhu.c

Comments

Jassi Brar June 22, 2016, 4:31 a.m. UTC | #1
On Tue, Jun 21, 2016 at 3:32 PM, Neil Armstrong <narmstrong@baylibre.com> wrote:
> Add Amlogic Meson SoCs Message-Handling-Unit as mailbox controller
> with 2 independent channels/links to communicate with a remote processor.
>
> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>

.....

> +++ b/drivers/mailbox/meson_mhu.c
> @@ -0,0 +1,199 @@
> +/*
> + * Copyright (C) 2016 BayLibre SAS.
> + * Author: Neil Armstrong <narmstrong@baylibre.com>
> + * Heavily based on meson_mhu.c from :
> + * Copyright (C) 2013-2015 Fujitsu Semiconductor Ltd.
> + * Copyright (C) 2015 Linaro Ltd.
> + * Author: Jassi Brar <jaswinder.singh@linaro.org>

.........
> +
> +#define INTR_SET_OFS   0x0
> +#define INTR_STAT_OFS  0x4
> +#define INTR_CLR_OFS   0x8
> +
> +#define MHU_LP_OFFSET  0x10
> +#define MHU_HP_OFFSET  0x1c
> +
> +#define TX_REG_OFFSET  0x24
> +
It seems only some register offsets have changed from arm_mhu. So
maybe just adapt the arm_mhu driver to look for IP variant and assign
corresponding offsets to set,stat,clr registers.

Cheers.
Neil Armstrong June 23, 2016, 12:50 p.m. UTC | #2
On 06/22/2016 06:31 AM, Jassi Brar wrote:
> On Tue, Jun 21, 2016 at 3:32 PM, Neil Armstrong <narmstrong@baylibre.com> wrote:
>> Add Amlogic Meson SoCs Message-Handling-Unit as mailbox controller
>> with 2 independent channels/links to communicate with a remote processor.
>>
>> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
> 
> .....
> 
>> +++ b/drivers/mailbox/meson_mhu.c
>> @@ -0,0 +1,199 @@
>> +/*
>> + * Copyright (C) 2016 BayLibre SAS.
>> + * Author: Neil Armstrong <narmstrong@baylibre.com>
>> + * Heavily based on meson_mhu.c from :
>> + * Copyright (C) 2013-2015 Fujitsu Semiconductor Ltd.
>> + * Copyright (C) 2015 Linaro Ltd.
>> + * Author: Jassi Brar <jaswinder.singh@linaro.org>
> 
> .........
>> +
>> +#define INTR_SET_OFS   0x0
>> +#define INTR_STAT_OFS  0x4
>> +#define INTR_CLR_OFS   0x8
>> +
>> +#define MHU_LP_OFFSET  0x10
>> +#define MHU_HP_OFFSET  0x1c
>> +
>> +#define TX_REG_OFFSET  0x24
>> +
> It seems only some register offsets have changed from arm_mhu. So
> maybe just adapt the arm_mhu driver to look for IP variant and assign
> corresponding offsets to set,stat,clr registers.

Hi Jassi,

It's a good idea, but adding the platform_driver support along the amba_bus probe will add a lot a code.
The meson_mhu is a very simple and short driver, I think it'll be simpler to maintain beeing separated.
And I'm not certain on how it's close of ARM's real IP.

Neil

> Cheers.
>
Jassi Brar July 4, 2016, 3:38 p.m. UTC | #3
On Tue, Jun 21, 2016 at 3:32 PM, Neil Armstrong <narmstrong@baylibre.com> wrote:
> Add Amlogic Meson SoCs Message-Handling-Unit as mailbox controller
> with 2 independent channels/links to communicate with a remote processor.
>
> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
> ---
>  drivers/mailbox/Makefile    |   2 +
>  drivers/mailbox/meson_mhu.c | 199 ++++++++++++++++++++++++++++++++++++++++++++
>
Can we call it pdev_mhu.c or similar so that some other platform using
the MHU as a platform_device wouldn't have to embarrassingly call it
'Meson's MHU'?  And also the replace meson with that prefix in the
code.

>  2 files changed, 201 insertions(+)
>  create mode 100644 drivers/mailbox/meson_mhu.c
>
> diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
> index 0be3e74..6aa9dbe 100644
> --- a/drivers/mailbox/Makefile
> +++ b/drivers/mailbox/Makefile
> @@ -25,3 +25,5 @@ obj-$(CONFIG_TI_MESSAGE_MANAGER) += ti-msgmgr.o
>  obj-$(CONFIG_XGENE_SLIMPRO_MBOX) += mailbox-xgene-slimpro.o
>
>  obj-$(CONFIG_HI6220_MBOX)      += hi6220-mailbox.o
> +
> +obj-$(CONFIG_ARCH_MESON)       += meson_mhu.o
> diff --git a/drivers/mailbox/meson_mhu.c b/drivers/mailbox/meson_mhu.c
> new file mode 100644
> index 0000000..0576b92
> --- /dev/null
> +++ b/drivers/mailbox/meson_mhu.c
> @@ -0,0 +1,199 @@
> +/*
> + * Copyright (C) 2016 BayLibre SAS.
> + * Author: Neil Armstrong <narmstrong@baylibre.com>
> + * Heavily based on meson_mhu.c from :
> + * 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/platform_device.h>
> +#include <linux/mailbox_controller.h>
> +
> +#define INTR_SET_OFS   0x0
> +#define INTR_STAT_OFS  0x4
> +#define INTR_CLR_OFS   0x8
> +
> +#define MHU_LP_OFFSET  0x10
> +#define MHU_HP_OFFSET  0x1c
> +
> +#define TX_REG_OFFSET  0x24
> +
> +#define MHU_CHANS      2
> +
> +struct meson_mhu_link {
> +       unsigned int irq;
> +       void __iomem *tx_reg;
> +       void __iomem *rx_reg;
> +};
> +
> +struct meson_mhu {
> +       void __iomem *base;
> +       struct meson_mhu_link mlink[MHU_CHANS];
> +       struct mbox_chan chan[MHU_CHANS];
> +       struct mbox_controller mbox;
> +};
> +
> +static irqreturn_t meson_mhu_rx_interrupt(int irq, void *p)
> +{
> +       struct mbox_chan *chan = p;
> +       struct meson_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(~0, mlink->rx_reg + INTR_CLR_OFS);
> +
How about sync with arm_mhu.c by doing writel_relaxed(val,
mlink->rx_reg + INTR_CLR_OFS) ?


> +       return IRQ_HANDLED;
> +}
> +
> +static bool meson_mhu_last_tx_done(struct mbox_chan *chan)
> +{
> +       struct meson_mhu_link *mlink = chan->con_priv;
> +       u32 val = readl_relaxed(mlink->tx_reg + INTR_STAT_OFS);
> +
> +       return (val == 0);
> +}
> +
> +static int meson_mhu_send_data(struct mbox_chan *chan, void *data)
> +{
> +       struct meson_mhu_link *mlink = chan->con_priv;
> +       u32 *arg = data;
> +
> +       writel_relaxed(*arg, mlink->tx_reg + INTR_SET_OFS);
> +
> +       return 0;
> +}
> +
> +static int meson_mhu_startup(struct mbox_chan *chan)
> +{
> +       struct meson_mhu_link *mlink = chan->con_priv;
> +       int ret;
> +
arm_mhu.c clears any pending TX before taking over by doing ...
       val = readl_relaxed(mlink->tx_reg + INTR_STAT_OFS);
       writel_relaxed(val, mlink->tx_reg + INTR_CLR_OFS);

> +       ret = request_irq(mlink->irq, meson_mhu_rx_interrupt,
> +                         IRQF_ONESHOT, "meson_mhu_link", chan);
> +       if (ret) {
> +               dev_err(chan->mbox->dev,
> +                       "Unable to acquire IRQ %d\n", mlink->irq);
> +               return ret;
> +       }
> +
> +       return 0;
> +}
> +
> +static void meson_mhu_shutdown(struct mbox_chan *chan)
> +{
> +       struct meson_mhu_link *mlink = chan->con_priv;
> +
> +       free_irq(mlink->irq, chan);
> +}
> +
> +static const struct mbox_chan_ops meson_mhu_ops = {
> +       .send_data = meson_mhu_send_data,
> +       .startup = meson_mhu_startup,
> +       .shutdown = meson_mhu_shutdown,
> +       .last_tx_done = meson_mhu_last_tx_done,
> +};
>
My two comments above may not be necessary for your platform, but I
would suggest we keep the core (from the declaration of struct
meson_mhu_link to this point) in sync with arm_mhu.c

> +static int meson_mhu_probe(struct platform_device *pdev)
> +{
> +       int i, err;
> +       struct meson_mhu *mhu;
> +       struct device *dev = &pdev->dev;
> +       struct resource *res;
> +       int meson_mhu_reg[MHU_CHANS] = {MHU_LP_OFFSET, MHU_HP_OFFSET};
> +
> +       /* Allocate memory for device */
> +       mhu = devm_kzalloc(dev, sizeof(*mhu), GFP_KERNEL);
> +       if (!mhu)
> +               return -ENOMEM;
> +
> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +       mhu->base = devm_ioremap_resource(dev, 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 = platform_get_irq(pdev, i);
> +               if (mhu->mlink[i].irq < 0) {
> +                       dev_err(dev, "failed to get irq%d\n", i);
> +                       return mhu->mlink[i].irq;
> +               }
> +               mhu->mlink[i].rx_reg = mhu->base + meson_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 = &meson_mhu_ops;
> +       mhu->mbox.txdone_irq = false;
> +       mhu->mbox.txdone_poll = true;
> +       mhu->mbox.txpoll_period = 1;
> +
> +       platform_set_drvdata(pdev, mhu);
> +
> +       err = mbox_controller_register(&mhu->mbox);
> +       if (err) {
> +               dev_err(dev, "Failed to register mailboxes %d\n", err);
> +               return err;
> +       }
> +
> +       dev_info(dev, "Meson MHU Mailbox registered\n");
> +       return 0;
> +}
> +
> +static int meson_mhu_remove(struct platform_device *pdev)
> +{
> +       struct meson_mhu *mhu = platform_get_drvdata(pdev);
> +
> +       mbox_controller_unregister(&mhu->mbox);
> +
> +       return 0;
> +}
> +
> +static const struct of_device_id meson_mhu_dt_ids[] = {
> +       { .compatible = "amlogic,meson-gxbb-mhu", },
> +       { /* sentinel */ },
> +};
> +MODULE_DEVICE_TABLE(of, meson_mhu_ids);
> +
> +static struct platform_driver meson_wdt_driver = {
> +       .probe  = meson_mhu_probe,
> +       .remove = meson_mhu_remove,
> +       .driver = {
> +               .name = "meson-mhu",
> +               .of_match_table = meson_mhu_dt_ids,
> +       },
> +};
> +
> +module_platform_driver(meson_wdt_driver);
> +
wdt as in watchdog-timer from drivers/watchdog/meson_wdt.c ? :)

Thanks.
Neil Armstrong July 6, 2016, 1:17 p.m. UTC | #4
2016-07-04 17:38 GMT+02:00 Jassi Brar <jassisinghbrar@gmail.com>:
> On Tue, Jun 21, 2016 at 3:32 PM, Neil Armstrong <narmstrong@baylibre.com> wrote:
>> Add Amlogic Meson SoCs Message-Handling-Unit as mailbox controller
>> with 2 independent channels/links to communicate with a remote processor.
>>
>> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
>> ---
>>  drivers/mailbox/Makefile    |   2 +
>>  drivers/mailbox/meson_mhu.c | 199 ++++++++++++++++++++++++++++++++++++++++++++
>>
> Can we call it pdev_mhu.c or similar so that some other platform using
> the MHU as a platform_device wouldn't have to embarrassingly call it
> 'Meson's MHU'?  And also the replace meson with that prefix in the
> code.

Yes, it may deserve a more generic naming, but pdev_mhu is not good
looking at all !
What about platform_mhu ?

>
>>  2 files changed, 201 insertions(+)
>>  create mode 100644 drivers/mailbox/meson_mhu.c
>>
>> diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
>> index 0be3e74..6aa9dbe 100644
>> --- a/drivers/mailbox/Makefile
>> +++ b/drivers/mailbox/Makefile
>> @@ -25,3 +25,5 @@ obj-$(CONFIG_TI_MESSAGE_MANAGER) += ti-msgmgr.o
>>  obj-$(CONFIG_XGENE_SLIMPRO_MBOX) += mailbox-xgene-slimpro.o
>>
>>  obj-$(CONFIG_HI6220_MBOX)      += hi6220-mailbox.o
>> +
>> +obj-$(CONFIG_ARCH_MESON)       += meson_mhu.o
>> diff --git a/drivers/mailbox/meson_mhu.c b/drivers/mailbox/meson_mhu.c
>> new file mode 100644
>> index 0000000..0576b92
>> --- /dev/null
>> +++ b/drivers/mailbox/meson_mhu.c
>> @@ -0,0 +1,199 @@
>> +/*
>> + * Copyright (C) 2016 BayLibre SAS.
>> + * Author: Neil Armstrong <narmstrong@baylibre.com>
>> + * Heavily based on meson_mhu.c from :
>> + * 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/platform_device.h>
>> +#include <linux/mailbox_controller.h>
>> +
>> +#define INTR_SET_OFS   0x0
>> +#define INTR_STAT_OFS  0x4
>> +#define INTR_CLR_OFS   0x8
>> +
>> +#define MHU_LP_OFFSET  0x10
>> +#define MHU_HP_OFFSET  0x1c
>> +
>> +#define TX_REG_OFFSET  0x24
>> +
>> +#define MHU_CHANS      2
>> +
>> +struct meson_mhu_link {
>> +       unsigned int irq;
>> +       void __iomem *tx_reg;
>> +       void __iomem *rx_reg;
>> +};
>> +
>> +struct meson_mhu {
>> +       void __iomem *base;
>> +       struct meson_mhu_link mlink[MHU_CHANS];
>> +       struct mbox_chan chan[MHU_CHANS];
>> +       struct mbox_controller mbox;
>> +};
>> +
>> +static irqreturn_t meson_mhu_rx_interrupt(int irq, void *p)
>> +{
>> +       struct mbox_chan *chan = p;
>> +       struct meson_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(~0, mlink->rx_reg + INTR_CLR_OFS);
>> +
> How about sync with arm_mhu.c by doing writel_relaxed(val,
> mlink->rx_reg + INTR_CLR_OFS) ?

The ~0 was taken from the vendor driver, but writing val should work,
I must test this change.

>
>> +       return IRQ_HANDLED;
>> +}
>> +
>> +static bool meson_mhu_last_tx_done(struct mbox_chan *chan)
>> +{
>> +       struct meson_mhu_link *mlink = chan->con_priv;
>> +       u32 val = readl_relaxed(mlink->tx_reg + INTR_STAT_OFS);
>> +
>> +       return (val == 0);
>> +}
>> +
>> +static int meson_mhu_send_data(struct mbox_chan *chan, void *data)
>> +{
>> +       struct meson_mhu_link *mlink = chan->con_priv;
>> +       u32 *arg = data;
>> +
>> +       writel_relaxed(*arg, mlink->tx_reg + INTR_SET_OFS);
>> +
>> +       return 0;
>> +}
>> +
>> +static int meson_mhu_startup(struct mbox_chan *chan)
>> +{
>> +       struct meson_mhu_link *mlink = chan->con_priv;
>> +       int ret;
>> +
> arm_mhu.c clears any pending TX before taking over by doing ...
>        val = readl_relaxed(mlink->tx_reg + INTR_STAT_OFS);
>        writel_relaxed(val, mlink->tx_reg + INTR_CLR_OFS);

I dropped it not knowing it it was necessary because not pressent in
the vendor code, but yes it would clearly be good to get it back.

>> +       ret = request_irq(mlink->irq, meson_mhu_rx_interrupt,
>> +                         IRQF_ONESHOT, "meson_mhu_link", chan);
>> +       if (ret) {
>> +               dev_err(chan->mbox->dev,
>> +                       "Unable to acquire IRQ %d\n", mlink->irq);
>> +               return ret;
>> +       }
>> +
>> +       return 0;
>> +}
>> +
>> +static void meson_mhu_shutdown(struct mbox_chan *chan)
>> +{
>> +       struct meson_mhu_link *mlink = chan->con_priv;
>> +
>> +       free_irq(mlink->irq, chan);
>> +}
>> +
>> +static const struct mbox_chan_ops meson_mhu_ops = {
>> +       .send_data = meson_mhu_send_data,
>> +       .startup = meson_mhu_startup,
>> +       .shutdown = meson_mhu_shutdown,
>> +       .last_tx_done = meson_mhu_last_tx_done,
>> +};
>>
> My two comments above may not be necessary for your platform, but I
> would suggest we keep the core (from the declaration of struct
> meson_mhu_link to this point) in sync with arm_mhu.c

Yes, I'll keep them as synced as possible.

>> +static int meson_mhu_probe(struct platform_device *pdev)
>> +{
>> +       int i, err;
>> +       struct meson_mhu *mhu;
>> +       struct device *dev = &pdev->dev;
>> +       struct resource *res;
>> +       int meson_mhu_reg[MHU_CHANS] = {MHU_LP_OFFSET, MHU_HP_OFFSET};
>> +
>> +       /* Allocate memory for device */
>> +       mhu = devm_kzalloc(dev, sizeof(*mhu), GFP_KERNEL);
>> +       if (!mhu)
>> +               return -ENOMEM;
>> +
>> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +       mhu->base = devm_ioremap_resource(dev, 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 = platform_get_irq(pdev, i);
>> +               if (mhu->mlink[i].irq < 0) {
>> +                       dev_err(dev, "failed to get irq%d\n", i);
>> +                       return mhu->mlink[i].irq;
>> +               }
>> +               mhu->mlink[i].rx_reg = mhu->base + meson_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 = &meson_mhu_ops;
>> +       mhu->mbox.txdone_irq = false;
>> +       mhu->mbox.txdone_poll = true;
>> +       mhu->mbox.txpoll_period = 1;
>> +
>> +       platform_set_drvdata(pdev, mhu);
>> +
>> +       err = mbox_controller_register(&mhu->mbox);
>> +       if (err) {
>> +               dev_err(dev, "Failed to register mailboxes %d\n", err);
>> +               return err;
>> +       }
>> +
>> +       dev_info(dev, "Meson MHU Mailbox registered\n");
>> +       return 0;
>> +}
>> +
>> +static int meson_mhu_remove(struct platform_device *pdev)
>> +{
>> +       struct meson_mhu *mhu = platform_get_drvdata(pdev);
>> +
>> +       mbox_controller_unregister(&mhu->mbox);
>> +
>> +       return 0;
>> +}
>> +
>> +static const struct of_device_id meson_mhu_dt_ids[] = {
>> +       { .compatible = "amlogic,meson-gxbb-mhu", },
>> +       { /* sentinel */ },
>> +};
>> +MODULE_DEVICE_TABLE(of, meson_mhu_ids);
>> +
>> +static struct platform_driver meson_wdt_driver = {
>> +       .probe  = meson_mhu_probe,
>> +       .remove = meson_mhu_remove,
>> +       .driver = {
>> +               .name = "meson-mhu",
>> +               .of_match_table = meson_mhu_dt_ids,
>> +       },
>> +};
>> +
>> +module_platform_driver(meson_wdt_driver);
>> +
> wdt as in watchdog-timer from drivers/watchdog/meson_wdt.c ? :)

Sorry, it was a leftover from another pdev driver, but the freshly
pushed meson_gxbb_wdt !

> Thanks.

Thanks for the feedback,
Neil
Jassi Brar July 7, 2016, 4:27 a.m. UTC | #5
On Wed, Jul 6, 2016 at 6:47 PM, Neil Armstrong <narmstrong@baylibre.com> wrote:
> 2016-07-04 17:38 GMT+02:00 Jassi Brar <jassisinghbrar@gmail.com>:
>> On Tue, Jun 21, 2016 at 3:32 PM, Neil Armstrong <narmstrong@baylibre.com> wrote:
>>> Add Amlogic Meson SoCs Message-Handling-Unit as mailbox controller
>>> with 2 independent channels/links to communicate with a remote processor.
>>>
>>> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
>>> ---
>>>  drivers/mailbox/Makefile    |   2 +
>>>  drivers/mailbox/meson_mhu.c | 199 ++++++++++++++++++++++++++++++++++++++++++++
>>>
>> Can we call it pdev_mhu.c or similar so that some other platform using
>> the MHU as a platform_device wouldn't have to embarrassingly call it
>> 'Meson's MHU'?  And also the replace meson with that prefix in the
>> code.
>
> Yes, it may deserve a more generic naming, but pdev_mhu is not good
> looking at all !
> What about platform_mhu ?
>
OK

Patch
diff mbox

diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
index 0be3e74..6aa9dbe 100644
--- a/drivers/mailbox/Makefile
+++ b/drivers/mailbox/Makefile
@@ -25,3 +25,5 @@  obj-$(CONFIG_TI_MESSAGE_MANAGER) += ti-msgmgr.o
 obj-$(CONFIG_XGENE_SLIMPRO_MBOX) += mailbox-xgene-slimpro.o
 
 obj-$(CONFIG_HI6220_MBOX)	+= hi6220-mailbox.o
+
+obj-$(CONFIG_ARCH_MESON)	+= meson_mhu.o
diff --git a/drivers/mailbox/meson_mhu.c b/drivers/mailbox/meson_mhu.c
new file mode 100644
index 0000000..0576b92
--- /dev/null
+++ b/drivers/mailbox/meson_mhu.c
@@ -0,0 +1,199 @@ 
+/*
+ * Copyright (C) 2016 BayLibre SAS.
+ * Author: Neil Armstrong <narmstrong@baylibre.com>
+ * Heavily based on meson_mhu.c from :
+ * 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/platform_device.h>
+#include <linux/mailbox_controller.h>
+
+#define INTR_SET_OFS	0x0
+#define INTR_STAT_OFS	0x4
+#define INTR_CLR_OFS	0x8
+
+#define MHU_LP_OFFSET	0x10
+#define MHU_HP_OFFSET	0x1c
+
+#define TX_REG_OFFSET	0x24
+
+#define MHU_CHANS	2
+
+struct meson_mhu_link {
+	unsigned int irq;
+	void __iomem *tx_reg;
+	void __iomem *rx_reg;
+};
+
+struct meson_mhu {
+	void __iomem *base;
+	struct meson_mhu_link mlink[MHU_CHANS];
+	struct mbox_chan chan[MHU_CHANS];
+	struct mbox_controller mbox;
+};
+
+static irqreturn_t meson_mhu_rx_interrupt(int irq, void *p)
+{
+	struct mbox_chan *chan = p;
+	struct meson_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(~0, mlink->rx_reg + INTR_CLR_OFS);
+
+	return IRQ_HANDLED;
+}
+
+static bool meson_mhu_last_tx_done(struct mbox_chan *chan)
+{
+	struct meson_mhu_link *mlink = chan->con_priv;
+	u32 val = readl_relaxed(mlink->tx_reg + INTR_STAT_OFS);
+
+	return (val == 0);
+}
+
+static int meson_mhu_send_data(struct mbox_chan *chan, void *data)
+{
+	struct meson_mhu_link *mlink = chan->con_priv;
+	u32 *arg = data;
+
+	writel_relaxed(*arg, mlink->tx_reg + INTR_SET_OFS);
+
+	return 0;
+}
+
+static int meson_mhu_startup(struct mbox_chan *chan)
+{
+	struct meson_mhu_link *mlink = chan->con_priv;
+	int ret;
+
+	ret = request_irq(mlink->irq, meson_mhu_rx_interrupt,
+			  IRQF_ONESHOT, "meson_mhu_link", chan);
+	if (ret) {
+		dev_err(chan->mbox->dev,
+			"Unable to acquire IRQ %d\n", mlink->irq);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void meson_mhu_shutdown(struct mbox_chan *chan)
+{
+	struct meson_mhu_link *mlink = chan->con_priv;
+
+	free_irq(mlink->irq, chan);
+}
+
+static const struct mbox_chan_ops meson_mhu_ops = {
+	.send_data = meson_mhu_send_data,
+	.startup = meson_mhu_startup,
+	.shutdown = meson_mhu_shutdown,
+	.last_tx_done = meson_mhu_last_tx_done,
+};
+
+static int meson_mhu_probe(struct platform_device *pdev)
+{
+	int i, err;
+	struct meson_mhu *mhu;
+	struct device *dev = &pdev->dev;
+	struct resource *res;
+	int meson_mhu_reg[MHU_CHANS] = {MHU_LP_OFFSET, MHU_HP_OFFSET};
+
+	/* Allocate memory for device */
+	mhu = devm_kzalloc(dev, sizeof(*mhu), GFP_KERNEL);
+	if (!mhu)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	mhu->base = devm_ioremap_resource(dev, 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 = platform_get_irq(pdev, i);
+		if (mhu->mlink[i].irq < 0) {
+			dev_err(dev, "failed to get irq%d\n", i);
+			return mhu->mlink[i].irq;
+		}
+		mhu->mlink[i].rx_reg = mhu->base + meson_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 = &meson_mhu_ops;
+	mhu->mbox.txdone_irq = false;
+	mhu->mbox.txdone_poll = true;
+	mhu->mbox.txpoll_period = 1;
+
+	platform_set_drvdata(pdev, mhu);
+
+	err = mbox_controller_register(&mhu->mbox);
+	if (err) {
+		dev_err(dev, "Failed to register mailboxes %d\n", err);
+		return err;
+	}
+
+	dev_info(dev, "Meson MHU Mailbox registered\n");
+	return 0;
+}
+
+static int meson_mhu_remove(struct platform_device *pdev)
+{
+	struct meson_mhu *mhu = platform_get_drvdata(pdev);
+
+	mbox_controller_unregister(&mhu->mbox);
+
+	return 0;
+}
+
+static const struct of_device_id meson_mhu_dt_ids[] = {
+	{ .compatible = "amlogic,meson-gxbb-mhu", },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, meson_mhu_ids);
+
+static struct platform_driver meson_wdt_driver = {
+	.probe	= meson_mhu_probe,
+	.remove	= meson_mhu_remove,
+	.driver = {
+		.name = "meson-mhu",
+		.of_match_table	= meson_mhu_dt_ids,
+	},
+};
+
+module_platform_driver(meson_wdt_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:meson-mhu");
+MODULE_DESCRIPTION("Amlogic Meson MHU Driver");
+MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");