diff mbox

[PATCHv1,2/2] mailbox: Adding driver for Xilinx LogiCORE IP mailbox.

Message ID 1432317791-26851-3-git-send-email-moritz.fischer@ettus.com (mailing list archive)
State New, archived
Headers show

Commit Message

Moritz Fischer May 22, 2015, 6:03 p.m. UTC
The Xilinx LogiCORE IP mailbox is a FPGA core that allows for
interprocessor communication via AXI4 memory mapped / AXI4 stream
interfaces.

It is single channel per core and allows for transmit and receive.

Signed-off-by: Moritz Fischer <moritz.fischer@ettus.com>
---
 MAINTAINERS                      |   7 +
 drivers/mailbox/Kconfig          |   8 +
 drivers/mailbox/Makefile         |   2 +
 drivers/mailbox/mailbox-xilinx.c | 332 ++++++++++++++++++++++++++++++++++
 4 files changed, 349 insertions(+)

Comments

Moritz Fischer May 23, 2015, 12:08 a.m. UTC | #1
I apologize upfront for the double post, but I discovered and issue
with the v1 version I sent.

On Fri, May 22, 2015 at 11:03 AM, Moritz Fischer
<moritz.fischer@ettus.com> wrote:
> The Xilinx LogiCORE IP mailbox is a FPGA core that allows for
> interprocessor communication via AXI4 memory mapped / AXI4 stream
> interfaces.
>
> It is single channel per core and allows for transmit and receive.
>
> Signed-off-by: Moritz Fischer <moritz.fischer@ettus.com>
> ---
>  MAINTAINERS                      |   7 +
>  drivers/mailbox/Kconfig          |   8 +
>  drivers/mailbox/Makefile         |   2 +
>  drivers/mailbox/mailbox-xilinx.c | 332 ++++++++++++++++++++++++++++++++++
>  4 files changed, 349 insertions(+)
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index f8e0afb..f1f0d10 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -10986,6 +10986,13 @@ M:     John Linn <John.Linn@xilinx.com>
>  S:     Maintained
>  F:     drivers/net/ethernet/xilinx/xilinx_axienet*
>
> +XILINX MAILBOX DRIVER
> +M:     Moritz Fischer <moritz.fischer@ettus.com>
> +L:     linux-kernel@vger.kernel.org
> +S:     Maintained
> +F:     drivers/mailbox/mailbox-xilinx.c
> +F:     Documentation/devicetree/bindings/mailbox/xilinx-mailbox.txt
> +
>  XILINX UARTLITE SERIAL DRIVER
>  M:     Peter Korsgaard <jacmet@sunsite.dk>
>  L:     linux-serial@vger.kernel.org
> diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
> index 84b0a2d..e11e4b2 100644
> --- a/drivers/mailbox/Kconfig
> +++ b/drivers/mailbox/Kconfig
> @@ -60,4 +60,12 @@ config ALTERA_MBOX
>           An implementation of the Altera Mailbox soft core. It is used
>           to send message between processors. Say Y here if you want to use the
>           Altera mailbox support.
> +
> +config XILINX_MBOX
> +       tristate "Xilinx Mailbox"
> +       help
> +         An implementation of the Xilinx Mailbox soft core. It is used
> +         to send message between processors. Say Y here if you want to use the
> +         Xilinx mailbox support.
> +
>  endif
> diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
> index b18201e..d28a028 100644
> --- a/drivers/mailbox/Makefile
> +++ b/drivers/mailbox/Makefile
> @@ -11,3 +11,5 @@ obj-$(CONFIG_OMAP2PLUS_MBOX)  += omap-mailbox.o
>  obj-$(CONFIG_PCC)              += pcc.o
>
>  obj-$(CONFIG_ALTERA_MBOX)      += mailbox-altera.o
> +
> +obj-$(CONFIG_XILINX_MBOX)      += mailbox-xilinx.o
> diff --git a/drivers/mailbox/mailbox-xilinx.c b/drivers/mailbox/mailbox-xilinx.c
> new file mode 100644
> index 0000000..3c45854
> --- /dev/null
> +++ b/drivers/mailbox/mailbox-xilinx.c
> @@ -0,0 +1,332 @@
> +/*
> + * Copyright (c) 2015, National Instruments Corp. All rights reserved.
> + *
> + * Driver for the Xilinx LogiCORE mailbox IP block
> + *
> + * 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/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/kernel.h>
> +#include <linux/mailbox_controller.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +
> +#define DRIVER_NAME "xilinx-mailbox"
> +
> +/* register offsets */
> +#define MAILBOX_REG_WRDATA     0x00
> +#define MAILBOX_REG_RDDATA     0x08
> +#define MAILBOX_REG_STATUS     0x10
> +#define MAILBOX_REG_ERROR      0x14
> +#define MAILBOX_REG_SIT        0x18
> +#define MAILBOX_REG_RIT        0x1c
> +#define MAILBOX_REG_IS 0x20
> +#define MAILBOX_REG_IE 0x24
> +#define MAILBOX_REG_IP 0x28
> +
> +/* status register */
> +#define STS_RTA        BIT(3)
> +#define STS_STA        BIT(2)
> +#define STS_FULL       BIT(1)
> +#define STS_EMPTY      BIT(0)
> +
> +/* error register */
> +#define ERR_FULL       BIT(1)
> +#define ERR_EMPTY      BIT(0)
> +
> +/* mailbox interrupt status register */
> +#define INT_STATUS_ERR BIT(2)
> +#define INT_STATUS_RTI BIT(1)
> +#define INT_STATUS_STI BIT(0)
> +
> +/* mailbox interrupt enable register */
> +#define INT_ENABLE_ERR BIT(2)
> +#define INT_ENABLE_RTI BIT(1)
> +#define INT_ENABLE_STI BIT(0)
> +
> +#define MBOX_POLLING_MS                5       /* polling interval 5ms */
> +
> +struct xilinx_mbox {
> +       int irq;
> +       void __iomem *mbox_base;
> +       struct device *dev;
> +       struct mbox_controller controller;
> +
> +       /* if the controller supports only RX polling mode */
> +       struct timer_list rxpoll_timer;
> +};
> +
> +static struct xilinx_mbox *mbox_chan_to_xilinx_mbox(struct mbox_chan *chan)
> +{
> +       if (!chan || !chan->con_priv)
> +               return NULL;
> +
> +       return (struct xilinx_mbox *)chan->con_priv;
> +}
> +
> +static inline bool xilinx_mbox_full(struct xilinx_mbox *mbox)
> +{
> +       u32 status;
> +
> +       status = readl_relaxed(mbox->mbox_base + MAILBOX_REG_STATUS);
> +
> +       return status & STS_FULL;
> +}
> +
> +static inline bool xilinx_mbox_pending(struct xilinx_mbox *mbox)
> +{
> +       u32 status;
> +
> +       status = readl_relaxed(mbox->mbox_base + MAILBOX_REG_STATUS);
> +
> +       return !(status & STS_EMPTY);
> +}
> +
> +static void xilinx_mbox_intmask(struct xilinx_mbox *mbox, u32 mask, bool enable)
> +{
> +       u32 mask_reg;
> +
> +       mask_reg = readl_relaxed(mbox->mbox_base + MAILBOX_REG_IE);
> +       if (enable)
> +               mask_reg |= mask;
> +       else
> +               mask_reg &= ~mask;
> +       writel_relaxed(mask_reg, mbox->mbox_base + MAILBOX_REG_IE);
> +}
> +
> +
> +static inline void xilinx_mbox_rx_intmask(struct xilinx_mbox *mbox, bool enable)
> +{
> +       xilinx_mbox_intmask(mbox, INT_ENABLE_RTI, enable);
> +}
> +
> +static inline void xilinx_mbox_tx_intmask(struct xilinx_mbox *mbox, bool enable)
> +{
> +       xilinx_mbox_intmask(mbox, INT_ENABLE_STI, enable);
> +}
> +
> +static void xilinx_mbox_rx_data(struct mbox_chan *chan)
> +{
> +       struct xilinx_mbox *mbox = mbox_chan_to_xilinx_mbox(chan);
> +       u32 data;
> +
> +       if (xilinx_mbox_pending(mbox)) {
> +               data = readl_relaxed(mbox->mbox_base + MAILBOX_REG_RDDATA);
> +               mbox_chan_received_data(chan, (void *)data);
> +       }
> +}
> +
> +static void xilinx_mbox_poll_rx(unsigned long data)
> +{
> +       struct mbox_chan *chan = (struct mbox_chan *)data;
> +       struct xilinx_mbox *mbox = mbox_chan_to_xilinx_mbox(chan);
> +
> +       xilinx_mbox_rx_data(chan);
> +
> +       mod_timer(&mbox->rxpoll_timer,
> +                 jiffies + msecs_to_jiffies(MBOX_POLLING_MS));
> +}
> +
> +static irqreturn_t xilinx_mbox_interrupt(int irq, void *p)
> +{
> +       u32 mask;
> +       struct mbox_chan *chan = (struct mbox_chan *)p;
> +       struct xilinx_mbox *mbox = mbox_chan_to_xilinx_mbox(chan);
> +
> +       mask = readl_relaxed(mbox->mbox_base + MAILBOX_REG_IS);
> +       if (mask & INT_STATUS_RTI)
> +               xilinx_mbox_rx_data(chan);
> +
> +       /* mask irqs *before* notifying done, require tx_block=true */
> +       if (mask & INT_STATUS_STI) {
> +               xilinx_mbox_tx_intmask(mbox, false);
> +               mbox_chan_txdone(chan, 0);
> +       }
> +
> +       writel_relaxed(mask, mbox->mbox_base + MAILBOX_REG_IS);
> +       return IRQ_HANDLED;
> +}
> +
> +static int xilinx_mbox_startup(struct mbox_chan *chan)
> +{
> +       int ret;
> +       struct xilinx_mbox *mbox = mbox_chan_to_xilinx_mbox(chan);
> +
> +       if (mbox->irq >= 0) {
> +               ret = request_irq(mbox->irq, xilinx_mbox_interrupt, 0,
> +                                 dev_name(mbox->dev), chan);
> +               if (unlikely(ret)) {
> +                       dev_err(mbox->dev,
> +                               "failed to register mailbox interrupt:%d\n",
> +                               ret);
> +                       goto polling; /* use polling if failed */
> +               }
> +

For the case that IRQs were missed before I should proabably add a:
while(xilinx_mbox_pending(mbox))
               xilinx_mbox_rx_data(chan);

Opinions?
> +               xilinx_mbox_rx_intmask(mbox, true);
> +               return 0;
> +       }
> +
> +polling:
> +       /* setup polling timer */
> +       setup_timer(&mbox->rxpoll_timer, xilinx_mbox_poll_rx,
> +                   (unsigned long)chan);
> +       mod_timer(&mbox->rxpoll_timer,
> +                 jiffies + msecs_to_jiffies(MBOX_POLLING_MS));
> +
> +       return 0;
> +}
> +
> +static int xilinx_mbox_send_data(struct mbox_chan *chan, void *data)
> +{
> +       struct xilinx_mbox *mbox = mbox_chan_to_xilinx_mbox(chan);
> +       u32 *udata = (u32 *)data;
> +
> +       if (!mbox || !data)
> +               return -EINVAL;
> +
> +       if (xilinx_mbox_full(mbox))
> +               return -EBUSY;
> +
> +       /* enable interrupt before send */
> +       if (mbox->irq >= 0)
> +               xilinx_mbox_tx_intmask(mbox, true);
> +
> +       writel_relaxed(*udata, mbox->mbox_base + MAILBOX_REG_WRDATA);
> +
> +       return 0;
> +}
> +
> +static bool xilinx_mbox_last_tx_done(struct mbox_chan *chan)
> +{
> +       struct xilinx_mbox *mbox = mbox_chan_to_xilinx_mbox(chan);
> +
> +       /* return false if mailbox is full */
> +       return !xilinx_mbox_full(mbox);
> +}
> +
> +static bool xilinx_mbox_peek_data(struct mbox_chan *chan)
> +{
> +       struct xilinx_mbox *mbox = mbox_chan_to_xilinx_mbox(chan);
> +
> +       return xilinx_mbox_pending(mbox);
> +}
> +
> +static void xilinx_mbox_shutdown(struct mbox_chan *chan)
> +{
> +       struct xilinx_mbox *mbox = mbox_chan_to_xilinx_mbox(chan);
> +
> +       if (mbox->irq >= 0) {
> +               /* mask all interrupts */
> +               writel_relaxed(0, mbox->mbox_base + MAILBOX_REG_IE);
> +               free_irq(mbox->irq, chan);
> +       } else {
> +               del_timer_sync(&mbox->rxpoll_timer);
> +       }
> +}
> +
> +static struct mbox_chan_ops xilinx_mbox_ops = {
> +       .send_data = xilinx_mbox_send_data,
> +       .startup = xilinx_mbox_startup,
> +       .shutdown = xilinx_mbox_shutdown,
> +       .last_tx_done = xilinx_mbox_last_tx_done,
> +       .peek_data = xilinx_mbox_peek_data,
> +};
> +
> +static int xilinx_mbox_probe(struct platform_device *pdev)
> +{
> +       struct xilinx_mbox *mbox;
> +       struct resource *regs;
> +       struct mbox_chan *chans;
> +       int ret;
> +
> +       mbox = devm_kzalloc(&pdev->dev, sizeof(*mbox), GFP_KERNEL);
> +       if (!mbox)
> +               return -ENOMEM;
> +
> +       /* allocated one channel */
> +       chans = devm_kzalloc(&pdev->dev, sizeof(*chans), GFP_KERNEL);
> +       if (!chans)
> +               return -ENOMEM;
> +
> +       regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +
> +       mbox->mbox_base = devm_ioremap_resource(&pdev->dev, regs);
> +       if (IS_ERR(mbox->mbox_base))
> +               return PTR_ERR(mbox->mbox_base);
> +
> +       mbox->irq = platform_get_irq(pdev, 0);
> +       /* if irq is present, we can use it, otherwise, poll */
> +       if (mbox->irq >= 0)
> +               mbox->controller.txdone_irq = true;
> +       else {
> +               dev_info(&pdev->dev, "IRQ not found, fallback to polling.\n");
> +               mbox->controller.txdone_poll = true;
> +               mbox->controller.txpoll_period = MBOX_POLLING_MS;
> +       }
> +
> +       mbox->dev = &pdev->dev;
> +
> +       /* hardware supports only one channel. */
> +       chans[0].con_priv = mbox;
> +       mbox->controller.dev = mbox->dev;
> +       mbox->controller.num_chans = 1;
> +       mbox->controller.chans = chans;
> +       mbox->controller.ops = &xilinx_mbox_ops;
> +
> +       ret = mbox_controller_register(&mbox->controller);
> +       if (ret) {
> +               dev_err(&pdev->dev, "Register mailbox failed\n");
> +               return ret;
> +       }
> +
> +       platform_set_drvdata(pdev, mbox);
> +
> +       return 0;
> +}
> +
> +
> +static int xilinx_mbox_remove(struct platform_device *pdev)
> +{
> +       struct xilinx_mbox *mbox = platform_get_drvdata(pdev);
> +
> +       if (!mbox)
> +               return -EINVAL;
> +
> +       mbox_controller_unregister(&mbox->controller);
> +
> +       return 0;
> +}
> +
> +static const struct of_device_id xilinx_mbox_match[] = {
> +       { .compatible = "xlnx,mailbox-2.1" },
> +       { /* sentinel */ }
> +};
> +
> +MODULE_DEVICE_TABLE(of, xilinx_mbox_match);
> +
> +static struct platform_driver xilinx_mbox_driver = {
> +       .probe  = xilinx_mbox_probe,
> +       .remove = xilinx_mbox_remove,
> +       .driver = {
> +               .name   = DRIVER_NAME,
> +               .of_match_table = xilinx_mbox_match,
> +       },
> +};
> +
> +module_platform_driver(xilinx_mbox_driver);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("Xilinx mailbox specific functions");
> +MODULE_AUTHOR("Moritz Fischer <moritz.fischer@ettus.com>");
> +MODULE_ALIAS("platform:xilinx-mailbox");
> --
> 2.4.1
>
diff mbox

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index f8e0afb..f1f0d10 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10986,6 +10986,13 @@  M:	John Linn <John.Linn@xilinx.com>
 S:	Maintained
 F:	drivers/net/ethernet/xilinx/xilinx_axienet*
 
+XILINX MAILBOX DRIVER
+M:	Moritz Fischer <moritz.fischer@ettus.com>
+L:	linux-kernel@vger.kernel.org
+S:	Maintained
+F:	drivers/mailbox/mailbox-xilinx.c
+F:	Documentation/devicetree/bindings/mailbox/xilinx-mailbox.txt
+
 XILINX UARTLITE SERIAL DRIVER
 M:	Peter Korsgaard <jacmet@sunsite.dk>
 L:	linux-serial@vger.kernel.org
diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
index 84b0a2d..e11e4b2 100644
--- a/drivers/mailbox/Kconfig
+++ b/drivers/mailbox/Kconfig
@@ -60,4 +60,12 @@  config ALTERA_MBOX
 	  An implementation of the Altera Mailbox soft core. It is used
 	  to send message between processors. Say Y here if you want to use the
 	  Altera mailbox support.
+
+config XILINX_MBOX
+	tristate "Xilinx Mailbox"
+	help
+	  An implementation of the Xilinx Mailbox soft core. It is used
+	  to send message between processors. Say Y here if you want to use the
+	  Xilinx mailbox support.
+
 endif
diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
index b18201e..d28a028 100644
--- a/drivers/mailbox/Makefile
+++ b/drivers/mailbox/Makefile
@@ -11,3 +11,5 @@  obj-$(CONFIG_OMAP2PLUS_MBOX)	+= omap-mailbox.o
 obj-$(CONFIG_PCC)		+= pcc.o
 
 obj-$(CONFIG_ALTERA_MBOX)	+= mailbox-altera.o
+
+obj-$(CONFIG_XILINX_MBOX)	+= mailbox-xilinx.o
diff --git a/drivers/mailbox/mailbox-xilinx.c b/drivers/mailbox/mailbox-xilinx.c
new file mode 100644
index 0000000..3c45854
--- /dev/null
+++ b/drivers/mailbox/mailbox-xilinx.c
@@ -0,0 +1,332 @@ 
+/*
+ * Copyright (c) 2015, National Instruments Corp. All rights reserved.
+ *
+ * Driver for the Xilinx LogiCORE mailbox IP block
+ *
+ * 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/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mailbox_controller.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+
+#define DRIVER_NAME "xilinx-mailbox"
+
+/* register offsets */
+#define MAILBOX_REG_WRDATA	0x00
+#define MAILBOX_REG_RDDATA	0x08
+#define MAILBOX_REG_STATUS	0x10
+#define MAILBOX_REG_ERROR	0x14
+#define MAILBOX_REG_SIT	0x18
+#define MAILBOX_REG_RIT	0x1c
+#define MAILBOX_REG_IS	0x20
+#define MAILBOX_REG_IE	0x24
+#define MAILBOX_REG_IP	0x28
+
+/* status register */
+#define STS_RTA	BIT(3)
+#define STS_STA	BIT(2)
+#define STS_FULL	BIT(1)
+#define STS_EMPTY	BIT(0)
+
+/* error register */
+#define ERR_FULL	BIT(1)
+#define ERR_EMPTY	BIT(0)
+
+/* mailbox interrupt status register */
+#define INT_STATUS_ERR	BIT(2)
+#define INT_STATUS_RTI	BIT(1)
+#define INT_STATUS_STI	BIT(0)
+
+/* mailbox interrupt enable register */
+#define INT_ENABLE_ERR	BIT(2)
+#define INT_ENABLE_RTI	BIT(1)
+#define INT_ENABLE_STI	BIT(0)
+
+#define MBOX_POLLING_MS		5	/* polling interval 5ms */
+
+struct xilinx_mbox {
+	int irq;
+	void __iomem *mbox_base;
+	struct device *dev;
+	struct mbox_controller controller;
+
+	/* if the controller supports only RX polling mode */
+	struct timer_list rxpoll_timer;
+};
+
+static struct xilinx_mbox *mbox_chan_to_xilinx_mbox(struct mbox_chan *chan)
+{
+	if (!chan || !chan->con_priv)
+		return NULL;
+
+	return (struct xilinx_mbox *)chan->con_priv;
+}
+
+static inline bool xilinx_mbox_full(struct xilinx_mbox *mbox)
+{
+	u32 status;
+
+	status = readl_relaxed(mbox->mbox_base + MAILBOX_REG_STATUS);
+
+	return status & STS_FULL;
+}
+
+static inline bool xilinx_mbox_pending(struct xilinx_mbox *mbox)
+{
+	u32 status;
+
+	status = readl_relaxed(mbox->mbox_base + MAILBOX_REG_STATUS);
+
+	return !(status & STS_EMPTY);
+}
+
+static void xilinx_mbox_intmask(struct xilinx_mbox *mbox, u32 mask, bool enable)
+{
+	u32 mask_reg;
+
+	mask_reg = readl_relaxed(mbox->mbox_base + MAILBOX_REG_IE);
+	if (enable)
+		mask_reg |= mask;
+	else
+		mask_reg &= ~mask;
+	writel_relaxed(mask_reg, mbox->mbox_base + MAILBOX_REG_IE);
+}
+
+
+static inline void xilinx_mbox_rx_intmask(struct xilinx_mbox *mbox, bool enable)
+{
+	xilinx_mbox_intmask(mbox, INT_ENABLE_RTI, enable);
+}
+
+static inline void xilinx_mbox_tx_intmask(struct xilinx_mbox *mbox, bool enable)
+{
+	xilinx_mbox_intmask(mbox, INT_ENABLE_STI, enable);
+}
+
+static void xilinx_mbox_rx_data(struct mbox_chan *chan)
+{
+	struct xilinx_mbox *mbox = mbox_chan_to_xilinx_mbox(chan);
+	u32 data;
+
+	if (xilinx_mbox_pending(mbox)) {
+		data = readl_relaxed(mbox->mbox_base + MAILBOX_REG_RDDATA);
+		mbox_chan_received_data(chan, (void *)data);
+	}
+}
+
+static void xilinx_mbox_poll_rx(unsigned long data)
+{
+	struct mbox_chan *chan = (struct mbox_chan *)data;
+	struct xilinx_mbox *mbox = mbox_chan_to_xilinx_mbox(chan);
+
+	xilinx_mbox_rx_data(chan);
+
+	mod_timer(&mbox->rxpoll_timer,
+		  jiffies + msecs_to_jiffies(MBOX_POLLING_MS));
+}
+
+static irqreturn_t xilinx_mbox_interrupt(int irq, void *p)
+{
+	u32 mask;
+	struct mbox_chan *chan = (struct mbox_chan *)p;
+	struct xilinx_mbox *mbox = mbox_chan_to_xilinx_mbox(chan);
+
+	mask = readl_relaxed(mbox->mbox_base + MAILBOX_REG_IS);
+	if (mask & INT_STATUS_RTI)
+		xilinx_mbox_rx_data(chan);
+
+	/* mask irqs *before* notifying done, require tx_block=true */
+	if (mask & INT_STATUS_STI) {
+		xilinx_mbox_tx_intmask(mbox, false);
+		mbox_chan_txdone(chan, 0);
+	}
+
+	writel_relaxed(mask, mbox->mbox_base + MAILBOX_REG_IS);
+	return IRQ_HANDLED;
+}
+
+static int xilinx_mbox_startup(struct mbox_chan *chan)
+{
+	int ret;
+	struct xilinx_mbox *mbox = mbox_chan_to_xilinx_mbox(chan);
+
+	if (mbox->irq >= 0) {
+		ret = request_irq(mbox->irq, xilinx_mbox_interrupt, 0,
+				  dev_name(mbox->dev), chan);
+		if (unlikely(ret)) {
+			dev_err(mbox->dev,
+				"failed to register mailbox interrupt:%d\n",
+				ret);
+			goto polling; /* use polling if failed */
+		}
+
+		xilinx_mbox_rx_intmask(mbox, true);
+		return 0;
+	}
+
+polling:
+	/* setup polling timer */
+	setup_timer(&mbox->rxpoll_timer, xilinx_mbox_poll_rx,
+		    (unsigned long)chan);
+	mod_timer(&mbox->rxpoll_timer,
+		  jiffies + msecs_to_jiffies(MBOX_POLLING_MS));
+
+	return 0;
+}
+
+static int xilinx_mbox_send_data(struct mbox_chan *chan, void *data)
+{
+	struct xilinx_mbox *mbox = mbox_chan_to_xilinx_mbox(chan);
+	u32 *udata = (u32 *)data;
+
+	if (!mbox || !data)
+		return -EINVAL;
+
+	if (xilinx_mbox_full(mbox))
+		return -EBUSY;
+
+	/* enable interrupt before send */
+	if (mbox->irq >= 0)
+		xilinx_mbox_tx_intmask(mbox, true);
+
+	writel_relaxed(*udata, mbox->mbox_base + MAILBOX_REG_WRDATA);
+
+	return 0;
+}
+
+static bool xilinx_mbox_last_tx_done(struct mbox_chan *chan)
+{
+	struct xilinx_mbox *mbox = mbox_chan_to_xilinx_mbox(chan);
+
+	/* return false if mailbox is full */
+	return !xilinx_mbox_full(mbox);
+}
+
+static bool xilinx_mbox_peek_data(struct mbox_chan *chan)
+{
+	struct xilinx_mbox *mbox = mbox_chan_to_xilinx_mbox(chan);
+
+	return xilinx_mbox_pending(mbox);
+}
+
+static void xilinx_mbox_shutdown(struct mbox_chan *chan)
+{
+	struct xilinx_mbox *mbox = mbox_chan_to_xilinx_mbox(chan);
+
+	if (mbox->irq >= 0) {
+		/* mask all interrupts */
+		writel_relaxed(0, mbox->mbox_base + MAILBOX_REG_IE);
+		free_irq(mbox->irq, chan);
+	} else {
+		del_timer_sync(&mbox->rxpoll_timer);
+	}
+}
+
+static struct mbox_chan_ops xilinx_mbox_ops = {
+	.send_data = xilinx_mbox_send_data,
+	.startup = xilinx_mbox_startup,
+	.shutdown = xilinx_mbox_shutdown,
+	.last_tx_done = xilinx_mbox_last_tx_done,
+	.peek_data = xilinx_mbox_peek_data,
+};
+
+static int xilinx_mbox_probe(struct platform_device *pdev)
+{
+	struct xilinx_mbox *mbox;
+	struct resource	*regs;
+	struct mbox_chan *chans;
+	int ret;
+
+	mbox = devm_kzalloc(&pdev->dev, sizeof(*mbox), GFP_KERNEL);
+	if (!mbox)
+		return -ENOMEM;
+
+	/* allocated one channel */
+	chans = devm_kzalloc(&pdev->dev, sizeof(*chans), GFP_KERNEL);
+	if (!chans)
+		return -ENOMEM;
+
+	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+	mbox->mbox_base = devm_ioremap_resource(&pdev->dev, regs);
+	if (IS_ERR(mbox->mbox_base))
+		return PTR_ERR(mbox->mbox_base);
+
+	mbox->irq = platform_get_irq(pdev, 0);
+	/* if irq is present, we can use it, otherwise, poll */
+	if (mbox->irq >= 0)
+		mbox->controller.txdone_irq = true;
+	else {
+		dev_info(&pdev->dev, "IRQ not found, fallback to polling.\n");
+		mbox->controller.txdone_poll = true;
+		mbox->controller.txpoll_period = MBOX_POLLING_MS;
+	}
+
+	mbox->dev = &pdev->dev;
+
+	/* hardware supports only one channel. */
+	chans[0].con_priv = mbox;
+	mbox->controller.dev = mbox->dev;
+	mbox->controller.num_chans = 1;
+	mbox->controller.chans = chans;
+	mbox->controller.ops = &xilinx_mbox_ops;
+
+	ret = mbox_controller_register(&mbox->controller);
+	if (ret) {
+		dev_err(&pdev->dev, "Register mailbox failed\n");
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, mbox);
+
+	return 0;
+}
+
+
+static int xilinx_mbox_remove(struct platform_device *pdev)
+{
+	struct xilinx_mbox *mbox = platform_get_drvdata(pdev);
+
+	if (!mbox)
+		return -EINVAL;
+
+	mbox_controller_unregister(&mbox->controller);
+
+	return 0;
+}
+
+static const struct of_device_id xilinx_mbox_match[] = {
+	{ .compatible = "xlnx,mailbox-2.1" },
+	{ /* sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(of, xilinx_mbox_match);
+
+static struct platform_driver xilinx_mbox_driver = {
+	.probe	= xilinx_mbox_probe,
+	.remove	= xilinx_mbox_remove,
+	.driver	= {
+		.name	= DRIVER_NAME,
+		.of_match_table	= xilinx_mbox_match,
+	},
+};
+
+module_platform_driver(xilinx_mbox_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Xilinx mailbox specific functions");
+MODULE_AUTHOR("Moritz Fischer <moritz.fischer@ettus.com>");
+MODULE_ALIAS("platform:xilinx-mailbox");