diff mbox

[v4,1/3] mailbox: Add support for APM X-Gene platform mailbox driver

Message ID abff73c051fd06a9dd3b04a1e7957ad5a9b69a18.1452912126.git.dhdang@apm.com (mailing list archive)
State New, archived
Headers show

Commit Message

Duc Dang Jan. 16, 2016, 2:57 a.m. UTC 
X-Gene mailbox controller provides 8 mailbox channels, with
each channel has a dedicated interrupt line.

Signed-off-by: Feng Kan <fkan@apm.com>
Signed-off-by: Duc Dang <dhdang@apm.com>
---
Changes since v3:
        - Rebase over v4.4
        - Remove 'id' in slimpro_mbox_chan structure
        - Remove small functions that are only called once
        and fold them into the other callers
        - Remove void* pointer type cast
        - Relax the number of mailbox IRQs condition
	- Use subsys_initcall to guarantee mailbox driver 
	will be registered before any other dependent driver
	is loaded.

 drivers/mailbox/Kconfig                 |   9 ++
 drivers/mailbox/Makefile                |   2 +
 drivers/mailbox/mailbox-xgene-slimpro.c | 265 ++++++++++++++++++++++++++++++++
 3 files changed, 276 insertions(+)
 create mode 100644 drivers/mailbox/mailbox-xgene-slimpro.c

Comments

kernel test robot Jan. 16, 2016, 12:31 p.m. UTC | #1 
Hi Duc,

[auto build test WARNING on robh/for-next]
[also build test WARNING on v4.4 next-20160115]
[if your patch is applied to the wrong git tree, please drop us a note to help improving the system]

url:    https://github.com/0day-ci/linux/commits/Duc-Dang/mailbox-Add-support-for-APM-X-Gene-platform-mailbox-driver/20160116-110535
base:   https://git.kernel.org/pub/scm/linux/kernel/git/robh/linux for-next
config: arm64-allyesconfig (attached as .config)
reproduce:
        wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        make.cross ARCH=arm64 

All warnings (new ones prefixed by >>):

>> WARNING: vmlinux.o(.data+0xfd6260): Section mismatch in reference from the variable slimpro_mbox_driver to the variable .init.text:$x
   The variable slimpro_mbox_driver references
   the variable __init $x
   If the reference is valid then annotate the
   variable with or __refdata (see linux/init.h) or name the variable:
   

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
Duc Dang Jan. 22, 2016, 11:05 p.m. UTC | #2 
On Sat, Jan 16, 2016 at 4:31 AM, kbuild test robot <lkp@intel.com> wrote:
> Hi Duc,
>
> [auto build test WARNING on robh/for-next]
> [also build test WARNING on v4.4 next-20160115]
> [if your patch is applied to the wrong git tree, please drop us a note to help improving the system]
>
> url:    https://github.com/0day-ci/linux/commits/Duc-Dang/mailbox-Add-support-for-APM-X-Gene-platform-mailbox-driver/20160116-110535
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/robh/linux for-next
> config: arm64-allyesconfig (attached as .config)
> reproduce:
>         wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         # save the attached .config to linux build tree
>         make.cross ARCH=arm64
>
> All warnings (new ones prefixed by >>):
>
>>> WARNING: vmlinux.o(.data+0xfd6260): Section mismatch in reference from the variable slimpro_mbox_driver to the variable .init.text:$x
>    The variable slimpro_mbox_driver references
>    the variable __init $x
>    If the reference is valid then annotate the
>    variable with or __refdata (see linux/init.h) or name the variable:

I fixed the build warning, will post and updated after further comment
from Jassi.

I did not catch it before posting my patch because I did not compile
with  CONFIG_DEBUG_SECTION_MISMATCH=y. I will make sure I have this
option enabled for my build process going forward.

Regards,
Duc Dang.
>
>
> ---
> 0-DAY kernel test infrastructure                Open Source Technology Center
> https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
Duc Dang Feb. 1, 2016, 7:38 p.m. UTC | #3 
Hi Jassi,

On Fri, Jan 15, 2016 at 6:57 PM, Duc Dang <dhdang@apm.com> wrote:
> X-Gene mailbox controller provides 8 mailbox channels, with
> each channel has a dedicated interrupt line.

Did you have a chance to look into this version 4 of my mail-box patch?

Regards,
Duc Dang.
>
> Signed-off-by: Feng Kan <fkan@apm.com>
> Signed-off-by: Duc Dang <dhdang@apm.com>
> ---
> Changes since v3:
>         - Rebase over v4.4
>         - Remove 'id' in slimpro_mbox_chan structure
>         - Remove small functions that are only called once
>         and fold them into the other callers
>         - Remove void* pointer type cast
>         - Relax the number of mailbox IRQs condition
>         - Use subsys_initcall to guarantee mailbox driver
>         will be registered before any other dependent driver
>         is loaded.
>
>  drivers/mailbox/Kconfig                 |   9 ++
>  drivers/mailbox/Makefile                |   2 +
>  drivers/mailbox/mailbox-xgene-slimpro.c | 265 ++++++++++++++++++++++++++++++++
>  3 files changed, 276 insertions(+)
>  create mode 100644 drivers/mailbox/mailbox-xgene-slimpro.c
>
> diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
> index 546d05f..678e434 100644
> --- a/drivers/mailbox/Kconfig
> +++ b/drivers/mailbox/Kconfig
> @@ -85,4 +85,13 @@ config MAILBOX_TEST
>           Test client to help with testing new Controller driver
>           implementations.
>
> +config XGENE_SLIMPRO_MBOX
> +       tristate "APM SoC X-Gene SLIMpro Mailbox Controller"
> +       depends on ARCH_XGENE
> +       help
> +         An implementation of the APM X-Gene Interprocessor Communication
> +         Mailbox (IPCM) between the ARM 64-bit cores and SLIMpro controller.
> +         It is used to send short messages between ARM64-bit cores and
> +         the SLIMpro Management Engine, primarily for PM. Say Y here if you
> +         want to use the APM X-Gene SLIMpro IPCM support.
>  endif
> diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
> index 92435ef..b602ef8 100644
> --- a/drivers/mailbox/Makefile
> +++ b/drivers/mailbox/Makefile
> @@ -17,3 +17,5 @@ obj-$(CONFIG_ALTERA_MBOX)     += mailbox-altera.o
>  obj-$(CONFIG_BCM2835_MBOX)     += bcm2835-mailbox.o
>
>  obj-$(CONFIG_STI_MBOX)         += mailbox-sti.o
> +
> +obj-$(CONFIG_XGENE_SLIMPRO_MBOX) += mailbox-xgene-slimpro.o
> diff --git a/drivers/mailbox/mailbox-xgene-slimpro.c b/drivers/mailbox/mailbox-xgene-slimpro.c
> new file mode 100644
> index 0000000..a7b0c9e
> --- /dev/null
> +++ b/drivers/mailbox/mailbox-xgene-slimpro.c
> @@ -0,0 +1,265 @@
> +/*
> + * APM X-Gene SLIMpro MailBox Driver
> + *
> + * Copyright (c) 2015, Applied Micro Circuits Corporation
> + * Author: Feng Kan fkan@apm.com
> + *
> + * 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; either version 2 of
> + * the License, or (at your option) any later version.
> + *
> + * 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, see <http://www.gnu.org/licenses/>.
> + *
> + */
> +#include <linux/acpi.h>
> +#include <linux/delay.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/mailbox_controller.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/spinlock.h>
> +
> +#define MBOX_CON_NAME                  "slimpro-mbox"
> +#define MBOX_REG_SET_OFFSET            0x1000
> +#define MBOX_CNT                       8
> +#define MBOX_STATUS_AVAIL_MASK         BIT(16)
> +#define MBOX_STATUS_ACK_MASK           BIT(0)
> +
> +/* Configuration and Status Registers */
> +#define REG_DB_IN              0x00
> +#define REG_DB_DIN0            0x04
> +#define REG_DB_DIN1            0x08
> +#define REG_DB_OUT             0x10
> +#define REG_DB_DOUT0           0x14
> +#define REG_DB_DOUT1           0x18
> +#define REG_DB_STAT            0x20
> +#define REG_DB_STATMASK                0x24
> +
> +struct slimpro_mbox_chan {
> +       struct device *dev;
> +       struct mbox_chan *chan;
> +       void __iomem *reg;
> +       int irq;
> +       u32 rx_msg[3];
> +};
> +
> +struct slimpro_mbox {
> +       struct mbox_controller mb_ctrl;
> +       struct slimpro_mbox_chan mc[MBOX_CNT];
> +       struct mbox_chan chans[MBOX_CNT];
> +};
> +
> +static void mb_chan_send_msg(struct slimpro_mbox_chan *mb_chan, u32 *msg)
> +{
> +       writel(msg[1], mb_chan->reg + REG_DB_DOUT0);
> +       writel(msg[2], mb_chan->reg + REG_DB_DOUT1);
> +       writel(msg[0], mb_chan->reg + REG_DB_OUT);
> +}
> +
> +static void mb_chan_recv_msg(struct slimpro_mbox_chan *mb_chan)
> +{
> +       mb_chan->rx_msg[1] = readl(mb_chan->reg + REG_DB_DIN0);
> +       mb_chan->rx_msg[2] = readl(mb_chan->reg + REG_DB_DIN1);
> +       mb_chan->rx_msg[0] = readl(mb_chan->reg + REG_DB_IN);
> +}
> +
> +static int mb_chan_status_ack(struct slimpro_mbox_chan *mb_chan)
> +{
> +       u32 val = readl(mb_chan->reg + REG_DB_STAT);
> +
> +       if (val & MBOX_STATUS_ACK_MASK) {
> +               writel(MBOX_STATUS_ACK_MASK, mb_chan->reg + REG_DB_STAT);
> +               return 1;
> +       }
> +       return 0;
> +}
> +
> +static int mb_chan_status_avail(struct slimpro_mbox_chan *mb_chan)
> +{
> +       u32 val = readl(mb_chan->reg + REG_DB_STAT);
> +
> +       if (val & MBOX_STATUS_AVAIL_MASK) {
> +               mb_chan_recv_msg(mb_chan);
> +               writel(MBOX_STATUS_AVAIL_MASK, mb_chan->reg + REG_DB_STAT);
> +               return 1;
> +       }
> +       return 0;
> +}
> +
> +static irqreturn_t slimpro_mbox_irq(int irq, void *id)
> +{
> +       struct slimpro_mbox_chan *mb_chan = id;
> +
> +       if (mb_chan_status_ack(mb_chan))
> +               mbox_chan_txdone(mb_chan->chan, 0);
> +
> +       if (mb_chan_status_avail(mb_chan))
> +               mbox_chan_received_data(mb_chan->chan, mb_chan->rx_msg);
> +
> +       return IRQ_HANDLED;
> +}
> +
> +static int slimpro_mbox_send_data(struct mbox_chan *chan, void *msg)
> +{
> +       struct slimpro_mbox_chan *mb_chan = chan->con_priv;
> +
> +       mb_chan_send_msg(mb_chan, msg);
> +       return 0;
> +}
> +
> +static int slimpro_mbox_startup(struct mbox_chan *chan)
> +{
> +       struct slimpro_mbox_chan *mb_chan = chan->con_priv;
> +       int rc;
> +       u32 val;
> +
> +       rc = devm_request_irq(mb_chan->dev, mb_chan->irq, slimpro_mbox_irq, 0,
> +                             MBOX_CON_NAME, mb_chan);
> +       if (unlikely(rc)) {
> +               dev_err(mb_chan->dev, "failed to register mailbox interrupt %d\n",
> +                       mb_chan->irq);
> +               return rc;
> +       }
> +
> +       /* Enable HW interrupt */
> +       writel(MBOX_STATUS_ACK_MASK | MBOX_STATUS_AVAIL_MASK,
> +              mb_chan->reg + REG_DB_STAT);
> +       /* Unmask doorbell status interrupt */
> +       val = readl(mb_chan->reg + REG_DB_STATMASK);
> +       val &= ~(MBOX_STATUS_ACK_MASK | MBOX_STATUS_AVAIL_MASK);
> +       writel(val, mb_chan->reg + REG_DB_STATMASK);
> +
> +       return 0;
> +}
> +
> +static void slimpro_mbox_shutdown(struct mbox_chan *chan)
> +{
> +       struct slimpro_mbox_chan *mb_chan = chan->con_priv;
> +       u32 val;
> +
> +       /* Mask doorbell status interrupt */
> +       val = readl(mb_chan->reg + REG_DB_STATMASK);
> +       val |= (MBOX_STATUS_ACK_MASK | MBOX_STATUS_AVAIL_MASK);
> +       writel(val, mb_chan->reg + REG_DB_STATMASK);
> +
> +       devm_free_irq(mb_chan->dev, mb_chan->irq, mb_chan);
> +}
> +
> +static struct mbox_chan_ops slimpro_mbox_ops = {
> +       .send_data = slimpro_mbox_send_data,
> +       .startup = slimpro_mbox_startup,
> +       .shutdown = slimpro_mbox_shutdown,
> +};
> +
> +static int __init slimpro_mbox_probe(struct platform_device *pdev)
> +{
> +       struct slimpro_mbox *ctx;
> +       struct resource *regs;
> +       void __iomem *mb_base;
> +       int rc;
> +       int i;
> +
> +       ctx = devm_kzalloc(&pdev->dev, sizeof(struct slimpro_mbox), GFP_KERNEL);
> +       if (IS_ERR(ctx))
> +               return PTR_ERR(ctx);
> +
> +       platform_set_drvdata(pdev, ctx);
> +
> +       regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +       mb_base = devm_ioremap(&pdev->dev, regs->start, resource_size(regs));
> +       if (IS_ERR(mb_base))
> +               return PTR_ERR(mb_base);
> +
> +       /* Setup mailbox links */
> +       for (i = 0; i < MBOX_CNT; i++) {
> +               ctx->mc[i].irq = platform_get_irq(pdev, i);
> +               if (ctx->mc[i].irq < 0) {
> +                       if (i == 0) {
> +                               dev_err(&pdev->dev, "no available IRQ\n");
> +                               return -EINVAL;
> +                       }
> +                       dev_info(&pdev->dev, "no IRQ at index %d\n",
> +                               ctx->mc[i].irq);
> +                       break;
> +               }
> +
> +               ctx->mc[i].dev = &pdev->dev;
> +               ctx->mc[i].reg = mb_base + i * MBOX_REG_SET_OFFSET;
> +               ctx->mc[i].chan = &ctx->chans[i];
> +               ctx->chans[i].con_priv = &ctx->mc[i];
> +       }
> +
> +       /* Setup mailbox controller */
> +       ctx->mb_ctrl.dev = &pdev->dev;
> +       ctx->mb_ctrl.chans = ctx->chans;
> +       ctx->mb_ctrl.txdone_irq = true;
> +       ctx->mb_ctrl.ops = &slimpro_mbox_ops;
> +       ctx->mb_ctrl.num_chans = i;
> +
> +       rc = mbox_controller_register(&ctx->mb_ctrl);
> +       if (rc) {
> +               dev_err(&pdev->dev,
> +                       "APM X-Gene SLIMpro MailBox register failed:%d\n", rc);
> +               return rc;
> +       }
> +
> +       dev_info(&pdev->dev, "APM X-Gene SLIMpro MailBox registered\n");
> +       return 0;
> +}
> +
> +static int slimpro_mbox_remove(struct platform_device *pdev)
> +{
> +       struct slimpro_mbox *smb = platform_get_drvdata(pdev);
> +
> +       mbox_controller_unregister(&smb->mb_ctrl);
> +       return 0;
> +}
> +
> +static const struct of_device_id slimpro_of_match[] = {
> +       {.compatible = "apm,xgene-slimpro-mbox" },
> +       { },
> +};
> +MODULE_DEVICE_TABLE(of, slimpro_of_match);
> +
> +#ifdef CONFIG_ACPI
> +static const struct acpi_device_id slimpro_acpi_ids[] = {
> +       {"APMC0D01", 0},
> +       {}
> +};
> +MODULE_DEVICE_TABLE(acpi, slimpro_acpi_ids);
> +#endif
> +
> +static struct platform_driver slimpro_mbox_driver = {
> +       .probe  = slimpro_mbox_probe,
> +       .remove = slimpro_mbox_remove,
> +       .driver = {
> +               .name = "xgene-slimpro-mbox",
> +               .of_match_table = of_match_ptr(slimpro_of_match),
> +               .acpi_match_table = ACPI_PTR(slimpro_acpi_ids)
> +       },
> +};
> +
> +static int __init slimpro_mbox_init(void)
> +{
> +       return platform_driver_register(&slimpro_mbox_driver);
> +}
> +
> +static void __exit slimpro_mbox_exit(void)
> +{
> +       platform_driver_unregister(&slimpro_mbox_driver);
> +}
> +
> +subsys_initcall(slimpro_mbox_init);
> +module_exit(slimpro_mbox_exit);
> +
> +MODULE_DESCRIPTION("APM X-Gene SLIMpro Mailbox Driver");
> +MODULE_LICENSE("GPL");
> --
> 1.9.1
>
Jassi Brar Feb. 2, 2016, 5:14 a.m. UTC | #4 
On Tue, Feb 2, 2016 at 1:08 AM, Duc Dang <dhdang@apm.com> wrote:
> Hi Jassi,
>
> On Fri, Jan 15, 2016 at 6:57 PM, Duc Dang <dhdang@apm.com> wrote:
>> X-Gene mailbox controller provides 8 mailbox channels, with
>> each channel has a dedicated interrupt line.
>
> Did you have a chance to look into this version 4 of my mail-box patch?
>
Seems ok, please just fix the "section mismatch" warnings reported by
the build-bot.

Thanks
Duc Dang Feb. 8, 2016, 10:04 p.m. UTC | #5 
APM X-Gene SoC has a mailbox controller that provides
communication mechanism for X-Gene Arm64 cores to communicate
with X-Gene SoC's Cortex M3 (SLIMpro) processor.

X-Gene mailbox controller provides 8 mailbox channels, with
each channel has a dedicated interrupt line.

Changes since v4:
        - Rebase over v4.5-rc1
        - Fix section mismatch warning during compiling
	- Correctly print channel number when there is
	no IRQ for that channel
        - Change node name to mailbox@10540000
        - Correct the number of IRQs in documentation

Changes since v3:
        - Rebase over v4.4
        - Remove 'id' in slimpro_mbox_chan structure
        - Remove functions that are only called once
        and fold them into the other callers
        - Remove void* pointer type cast
        - Relax the number of mailbox IRQs condition
        - Fix error and address comment in documentation
        (xgene-slimpro-mailbox.txt)

Changes since v2:
        - Rebase Feng's patch set over v4.3-rc5
        - Remove uneccessary 'inline' in function definition
        - Use module_platform_driver instead of subsys_initcall
        - Minor coding stype clean up

Changes since v1:
        - Add ACPI support
        - Use defines for reg offset

Duc Dang (3):
  mailbox: Add support for APM X-Gene platform mailbox driver
  Documentation: mailbox: Add APM X-Gene SLIMpro mailbox dts
    documentation
  arm64: dts: mailbox device tree node for APM X-Gene platform.

 .../bindings/mailbox/xgene-slimpro-mailbox.txt     |  35 +++
 arch/arm64/boot/dts/apm/apm-storm.dtsi             |  14 ++
 drivers/mailbox/Kconfig                            |   9 +
 drivers/mailbox/Makefile                           |   2 +
 drivers/mailbox/mailbox-xgene-slimpro.c            | 264 +++++++++++++++++++++
 5 files changed, 324 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mailbox/xgene-slimpro-mailbox.txt
 create mode 100644 drivers/mailbox/mailbox-xgene-slimpro.c
diff mbox

Patch

diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
index 546d05f..678e434 100644
--- a/drivers/mailbox/Kconfig
+++ b/drivers/mailbox/Kconfig
@@ -85,4 +85,13 @@  config MAILBOX_TEST
 	  Test client to help with testing new Controller driver
 	  implementations.
 
+config XGENE_SLIMPRO_MBOX
+	tristate "APM SoC X-Gene SLIMpro Mailbox Controller"
+	depends on ARCH_XGENE
+	help
+	  An implementation of the APM X-Gene Interprocessor Communication
+	  Mailbox (IPCM) between the ARM 64-bit cores and SLIMpro controller.
+	  It is used to send short messages between ARM64-bit cores and
+	  the SLIMpro Management Engine, primarily for PM. Say Y here if you
+	  want to use the APM X-Gene SLIMpro IPCM support.
 endif
diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
index 92435ef..b602ef8 100644
--- a/drivers/mailbox/Makefile
+++ b/drivers/mailbox/Makefile
@@ -17,3 +17,5 @@  obj-$(CONFIG_ALTERA_MBOX)	+= mailbox-altera.o
 obj-$(CONFIG_BCM2835_MBOX)	+= bcm2835-mailbox.o
 
 obj-$(CONFIG_STI_MBOX)		+= mailbox-sti.o
+
+obj-$(CONFIG_XGENE_SLIMPRO_MBOX) += mailbox-xgene-slimpro.o
diff --git a/drivers/mailbox/mailbox-xgene-slimpro.c b/drivers/mailbox/mailbox-xgene-slimpro.c
new file mode 100644
index 0000000..a7b0c9e
--- /dev/null
+++ b/drivers/mailbox/mailbox-xgene-slimpro.c
@@ -0,0 +1,265 @@ 
+/*
+ * APM X-Gene SLIMpro MailBox Driver
+ *
+ * Copyright (c) 2015, Applied Micro Circuits Corporation
+ * Author: Feng Kan fkan@apm.com
+ *
+ * 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; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ *
+ */
+#include <linux/acpi.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/mailbox_controller.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+
+#define MBOX_CON_NAME			"slimpro-mbox"
+#define MBOX_REG_SET_OFFSET		0x1000
+#define MBOX_CNT			8
+#define MBOX_STATUS_AVAIL_MASK		BIT(16)
+#define MBOX_STATUS_ACK_MASK		BIT(0)
+
+/* Configuration and Status Registers */
+#define REG_DB_IN		0x00
+#define REG_DB_DIN0		0x04
+#define REG_DB_DIN1		0x08
+#define REG_DB_OUT		0x10
+#define REG_DB_DOUT0		0x14
+#define REG_DB_DOUT1		0x18
+#define REG_DB_STAT		0x20
+#define REG_DB_STATMASK		0x24
+
+struct slimpro_mbox_chan {
+	struct device *dev;
+	struct mbox_chan *chan;
+	void __iomem *reg;
+	int irq;
+	u32 rx_msg[3];
+};
+
+struct slimpro_mbox {
+	struct mbox_controller mb_ctrl;
+	struct slimpro_mbox_chan mc[MBOX_CNT];
+	struct mbox_chan chans[MBOX_CNT];
+};
+
+static void mb_chan_send_msg(struct slimpro_mbox_chan *mb_chan, u32 *msg)
+{
+	writel(msg[1], mb_chan->reg + REG_DB_DOUT0);
+	writel(msg[2], mb_chan->reg + REG_DB_DOUT1);
+	writel(msg[0], mb_chan->reg + REG_DB_OUT);
+}
+
+static void mb_chan_recv_msg(struct slimpro_mbox_chan *mb_chan)
+{
+	mb_chan->rx_msg[1] = readl(mb_chan->reg + REG_DB_DIN0);
+	mb_chan->rx_msg[2] = readl(mb_chan->reg + REG_DB_DIN1);
+	mb_chan->rx_msg[0] = readl(mb_chan->reg + REG_DB_IN);
+}
+
+static int mb_chan_status_ack(struct slimpro_mbox_chan *mb_chan)
+{
+	u32 val = readl(mb_chan->reg + REG_DB_STAT);
+
+	if (val & MBOX_STATUS_ACK_MASK) {
+		writel(MBOX_STATUS_ACK_MASK, mb_chan->reg + REG_DB_STAT);
+		return 1;
+	}
+	return 0;
+}
+
+static int mb_chan_status_avail(struct slimpro_mbox_chan *mb_chan)
+{
+	u32 val = readl(mb_chan->reg + REG_DB_STAT);
+
+	if (val & MBOX_STATUS_AVAIL_MASK) {
+		mb_chan_recv_msg(mb_chan);
+		writel(MBOX_STATUS_AVAIL_MASK, mb_chan->reg + REG_DB_STAT);
+		return 1;
+	}
+	return 0;
+}
+
+static irqreturn_t slimpro_mbox_irq(int irq, void *id)
+{
+	struct slimpro_mbox_chan *mb_chan = id;
+
+	if (mb_chan_status_ack(mb_chan))
+		mbox_chan_txdone(mb_chan->chan, 0);
+
+	if (mb_chan_status_avail(mb_chan))
+		mbox_chan_received_data(mb_chan->chan, mb_chan->rx_msg);
+
+	return IRQ_HANDLED;
+}
+
+static int slimpro_mbox_send_data(struct mbox_chan *chan, void *msg)
+{
+	struct slimpro_mbox_chan *mb_chan = chan->con_priv;
+
+	mb_chan_send_msg(mb_chan, msg);
+	return 0;
+}
+
+static int slimpro_mbox_startup(struct mbox_chan *chan)
+{
+	struct slimpro_mbox_chan *mb_chan = chan->con_priv;
+	int rc;
+	u32 val;
+
+	rc = devm_request_irq(mb_chan->dev, mb_chan->irq, slimpro_mbox_irq, 0,
+			      MBOX_CON_NAME, mb_chan);
+	if (unlikely(rc)) {
+		dev_err(mb_chan->dev, "failed to register mailbox interrupt %d\n",
+			mb_chan->irq);
+		return rc;
+	}
+
+	/* Enable HW interrupt */
+	writel(MBOX_STATUS_ACK_MASK | MBOX_STATUS_AVAIL_MASK,
+	       mb_chan->reg + REG_DB_STAT);
+	/* Unmask doorbell status interrupt */
+	val = readl(mb_chan->reg + REG_DB_STATMASK);
+	val &= ~(MBOX_STATUS_ACK_MASK | MBOX_STATUS_AVAIL_MASK);
+	writel(val, mb_chan->reg + REG_DB_STATMASK);
+
+	return 0;
+}
+
+static void slimpro_mbox_shutdown(struct mbox_chan *chan)
+{
+	struct slimpro_mbox_chan *mb_chan = chan->con_priv;
+	u32 val;
+
+	/* Mask doorbell status interrupt */
+	val = readl(mb_chan->reg + REG_DB_STATMASK);
+	val |= (MBOX_STATUS_ACK_MASK | MBOX_STATUS_AVAIL_MASK);
+	writel(val, mb_chan->reg + REG_DB_STATMASK);
+
+	devm_free_irq(mb_chan->dev, mb_chan->irq, mb_chan);
+}
+
+static struct mbox_chan_ops slimpro_mbox_ops = {
+	.send_data = slimpro_mbox_send_data,
+	.startup = slimpro_mbox_startup,
+	.shutdown = slimpro_mbox_shutdown,
+};
+
+static int __init slimpro_mbox_probe(struct platform_device *pdev)
+{
+	struct slimpro_mbox *ctx;
+	struct resource *regs;
+	void __iomem *mb_base;
+	int rc;
+	int i;
+
+	ctx = devm_kzalloc(&pdev->dev, sizeof(struct slimpro_mbox), GFP_KERNEL);
+	if (IS_ERR(ctx))
+		return PTR_ERR(ctx);
+
+	platform_set_drvdata(pdev, ctx);
+
+	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	mb_base = devm_ioremap(&pdev->dev, regs->start, resource_size(regs));
+	if (IS_ERR(mb_base))
+		return PTR_ERR(mb_base);
+
+	/* Setup mailbox links */
+	for (i = 0; i < MBOX_CNT; i++) {
+		ctx->mc[i].irq = platform_get_irq(pdev, i);
+		if (ctx->mc[i].irq < 0) {
+			if (i == 0) {
+				dev_err(&pdev->dev, "no available IRQ\n");
+				return -EINVAL;
+			}
+			dev_info(&pdev->dev, "no IRQ at index %d\n",
+				ctx->mc[i].irq);
+			break;
+		}
+
+		ctx->mc[i].dev = &pdev->dev;
+		ctx->mc[i].reg = mb_base + i * MBOX_REG_SET_OFFSET;
+		ctx->mc[i].chan = &ctx->chans[i];
+		ctx->chans[i].con_priv = &ctx->mc[i];
+	}
+
+	/* Setup mailbox controller */
+	ctx->mb_ctrl.dev = &pdev->dev;
+	ctx->mb_ctrl.chans = ctx->chans;
+	ctx->mb_ctrl.txdone_irq = true;
+	ctx->mb_ctrl.ops = &slimpro_mbox_ops;
+	ctx->mb_ctrl.num_chans = i;
+
+	rc = mbox_controller_register(&ctx->mb_ctrl);
+	if (rc) {
+		dev_err(&pdev->dev,
+			"APM X-Gene SLIMpro MailBox register failed:%d\n", rc);
+		return rc;
+	}
+
+	dev_info(&pdev->dev, "APM X-Gene SLIMpro MailBox registered\n");
+	return 0;
+}
+
+static int slimpro_mbox_remove(struct platform_device *pdev)
+{
+	struct slimpro_mbox *smb = platform_get_drvdata(pdev);
+
+	mbox_controller_unregister(&smb->mb_ctrl);
+	return 0;
+}
+
+static const struct of_device_id slimpro_of_match[] = {
+	{.compatible = "apm,xgene-slimpro-mbox" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, slimpro_of_match);
+
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id slimpro_acpi_ids[] = {
+	{"APMC0D01", 0},
+	{}
+};
+MODULE_DEVICE_TABLE(acpi, slimpro_acpi_ids);
+#endif
+
+static struct platform_driver slimpro_mbox_driver = {
+	.probe	= slimpro_mbox_probe,
+	.remove = slimpro_mbox_remove,
+	.driver	= {
+		.name = "xgene-slimpro-mbox",
+		.of_match_table = of_match_ptr(slimpro_of_match),
+		.acpi_match_table = ACPI_PTR(slimpro_acpi_ids)
+	},
+};
+
+static int __init slimpro_mbox_init(void)
+{
+	return platform_driver_register(&slimpro_mbox_driver);
+}
+
+static void __exit slimpro_mbox_exit(void)
+{
+	platform_driver_unregister(&slimpro_mbox_driver);
+}
+
+subsys_initcall(slimpro_mbox_init);
+module_exit(slimpro_mbox_exit);
+
+MODULE_DESCRIPTION("APM X-Gene SLIMpro Mailbox Driver");
+MODULE_LICENSE("GPL");