[PATCH v5 1/3] mailbox: Add support for APM X-Gene platform mailbox driver

Duc Dang
2016-02-08T22:04:07Z

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 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 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 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