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

Signed-off-by: Feng Kan <f...@apm.com>
Signed-off-by: Duc Dang <dhd...@apm.com>
---
Changes since v4:
        - Rebase over v4.5-rc1
        - Fix section mistmatch warning by removing
        __init in slimpro_mbox_probe declaration
        - Correctly print channel number when
        there is no IRQ for that channel

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 | 264 ++++++++++++++++++++++++++++++++
 3 files changed, 275 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..0ea1eb8
--- /dev/null
+++ b/drivers/mailbox/mailbox-xgene-slimpro.c
@@ -0,0 +1,264 @@
+/*
+ * APM X-Gene SLIMpro MailBox Driver
+ *
+ * Copyright (c) 2015, Applied Micro Circuits Corporation
+ * Author: Feng Kan f...@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 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 for channel %d\n", i);
+                       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

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