ARM / highbank: add support for pl320 IPC
authorRob Herring <rob.herring@calxeda.com>
Mon, 28 Jan 2013 16:13:14 +0000 (16:13 +0000)
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>
Fri, 1 Feb 2013 23:01:15 +0000 (00:01 +0100)
The pl320 IPC allows for interprocessor communication between the
highbank A9 and the EnergyCore Management Engine. The pl320 implements
a straightforward mailbox protocol.

Signed-off-by: Mark Langsdorf <mark.langsdorf@calxeda.com>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
arch/arm/mach-highbank/Kconfig
drivers/Kconfig
drivers/Makefile
drivers/mailbox/Kconfig [new file with mode: 0644]
drivers/mailbox/Makefile [new file with mode: 0644]
drivers/mailbox/pl320-ipc.c [new file with mode: 0644]
include/linux/mailbox.h [new file with mode: 0644]

index 551c97e87a78bedf6bae2e2c4d7e5f93496088c8..2388085beaa28597bc64520b0b598928b89ff999 100644 (file)
@@ -11,5 +11,7 @@ config ARCH_HIGHBANK
        select GENERIC_CLOCKEVENTS
        select HAVE_ARM_SCU
        select HAVE_SMP
+       select MAILBOX
+       select PL320_MBOX
        select SPARSE_IRQ
        select USE_OF
index f5fb0722a63a14c9155b58a86f69c82e6efa8d92..2b4e89ba15adafe1f6105c2dd06d5cfe0beaa8d1 100644 (file)
@@ -134,6 +134,8 @@ source "drivers/hwspinlock/Kconfig"
 
 source "drivers/clocksource/Kconfig"
 
+source "drivers/mailbox/Kconfig"
+
 source "drivers/iommu/Kconfig"
 
 source "drivers/remoteproc/Kconfig"
index 7863b9fee50bbc33793a2acb2f104c34c22b2bd0..a8d32f1094b4dca4204918c053e1aaa87a6babb9 100644 (file)
@@ -130,6 +130,7 @@ obj-y                               += platform/
 #common clk code
 obj-y                          += clk/
 
+obj-$(CONFIG_MAILBOX)          += mailbox/
 obj-$(CONFIG_HWSPINLOCK)       += hwspinlock/
 obj-$(CONFIG_NFC)              += nfc/
 obj-$(CONFIG_IOMMU_SUPPORT)    += iommu/
diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
new file mode 100644 (file)
index 0000000..9545c9f
--- /dev/null
@@ -0,0 +1,19 @@
+menuconfig MAILBOX
+       bool "Mailbox Hardware Support"
+       help
+         Mailbox is a framework to control hardware communication between
+         on-chip processors through queued messages and interrupt driven
+         signals. Say Y if your platform supports hardware mailboxes.
+
+if MAILBOX
+config PL320_MBOX
+       bool "ARM PL320 Mailbox"
+       depends on ARM_AMBA
+       help
+         An implementation of the ARM PL320 Interprocessor Communication
+         Mailbox (IPCM), tailored for the Calxeda Highbank. It is used to
+         send short messages between Highbank's A9 cores and the EnergyCore
+         Management Engine, primarily for cpufreq. Say Y here if you want
+         to use the PL320 IPCM support.
+
+endif
diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
new file mode 100644 (file)
index 0000000..543ad6a
--- /dev/null
@@ -0,0 +1 @@
+obj-$(CONFIG_PL320_MBOX)       += pl320-ipc.o
diff --git a/drivers/mailbox/pl320-ipc.c b/drivers/mailbox/pl320-ipc.c
new file mode 100644 (file)
index 0000000..c45b3ae
--- /dev/null
@@ -0,0 +1,199 @@
+/*
+ * Copyright 2012 Calxeda, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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/types.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <linux/export.h>
+#include <linux/io.h>
+#include <linux/interrupt.h>
+#include <linux/completion.h>
+#include <linux/mutex.h>
+#include <linux/notifier.h>
+#include <linux/spinlock.h>
+#include <linux/device.h>
+#include <linux/amba/bus.h>
+
+#include <linux/mailbox.h>
+
+#define IPCMxSOURCE(m)         ((m) * 0x40)
+#define IPCMxDSET(m)           (((m) * 0x40) + 0x004)
+#define IPCMxDCLEAR(m)         (((m) * 0x40) + 0x008)
+#define IPCMxDSTATUS(m)                (((m) * 0x40) + 0x00C)
+#define IPCMxMODE(m)           (((m) * 0x40) + 0x010)
+#define IPCMxMSET(m)           (((m) * 0x40) + 0x014)
+#define IPCMxMCLEAR(m)         (((m) * 0x40) + 0x018)
+#define IPCMxMSTATUS(m)                (((m) * 0x40) + 0x01C)
+#define IPCMxSEND(m)           (((m) * 0x40) + 0x020)
+#define IPCMxDR(m, dr)         (((m) * 0x40) + ((dr) * 4) + 0x024)
+
+#define IPCMMIS(irq)           (((irq) * 8) + 0x800)
+#define IPCMRIS(irq)           (((irq) * 8) + 0x804)
+
+#define MBOX_MASK(n)           (1 << (n))
+#define IPC_TX_MBOX            1
+#define IPC_RX_MBOX            2
+
+#define CHAN_MASK(n)           (1 << (n))
+#define A9_SOURCE              1
+#define M3_SOURCE              0
+
+static void __iomem *ipc_base;
+static int ipc_irq;
+static DEFINE_MUTEX(ipc_m1_lock);
+static DECLARE_COMPLETION(ipc_completion);
+static ATOMIC_NOTIFIER_HEAD(ipc_notifier);
+
+static inline void set_destination(int source, int mbox)
+{
+       __raw_writel(CHAN_MASK(source), ipc_base + IPCMxDSET(mbox));
+       __raw_writel(CHAN_MASK(source), ipc_base + IPCMxMSET(mbox));
+}
+
+static inline void clear_destination(int source, int mbox)
+{
+       __raw_writel(CHAN_MASK(source), ipc_base + IPCMxDCLEAR(mbox));
+       __raw_writel(CHAN_MASK(source), ipc_base + IPCMxMCLEAR(mbox));
+}
+
+static void __ipc_send(int mbox, u32 *data)
+{
+       int i;
+       for (i = 0; i < 7; i++)
+               __raw_writel(data[i], ipc_base + IPCMxDR(mbox, i));
+       __raw_writel(0x1, ipc_base + IPCMxSEND(mbox));
+}
+
+static u32 __ipc_rcv(int mbox, u32 *data)
+{
+       int i;
+       for (i = 0; i < 7; i++)
+               data[i] = __raw_readl(ipc_base + IPCMxDR(mbox, i));
+       return data[1];
+}
+
+/* blocking implmentation from the A9 side, not usuable in interrupts! */
+int pl320_ipc_transmit(u32 *data)
+{
+       int ret;
+
+       mutex_lock(&ipc_m1_lock);
+
+       init_completion(&ipc_completion);
+       __ipc_send(IPC_TX_MBOX, data);
+       ret = wait_for_completion_timeout(&ipc_completion,
+                                         msecs_to_jiffies(1000));
+       if (ret == 0) {
+               ret = -ETIMEDOUT;
+               goto out;
+       }
+
+       ret = __ipc_rcv(IPC_TX_MBOX, data);
+out:
+       mutex_unlock(&ipc_m1_lock);
+       return ret;
+}
+EXPORT_SYMBOL_GPL(pl320_ipc_transmit);
+
+static irqreturn_t ipc_handler(int irq, void *dev)
+{
+       u32 irq_stat;
+       u32 data[7];
+
+       irq_stat = __raw_readl(ipc_base + IPCMMIS(1));
+       if (irq_stat & MBOX_MASK(IPC_TX_MBOX)) {
+               __raw_writel(0, ipc_base + IPCMxSEND(IPC_TX_MBOX));
+               complete(&ipc_completion);
+       }
+       if (irq_stat & MBOX_MASK(IPC_RX_MBOX)) {
+               __ipc_rcv(IPC_RX_MBOX, data);
+               atomic_notifier_call_chain(&ipc_notifier, data[0], data + 1);
+               __raw_writel(2, ipc_base + IPCMxSEND(IPC_RX_MBOX));
+       }
+
+       return IRQ_HANDLED;
+}
+
+int pl320_ipc_register_notifier(struct notifier_block *nb)
+{
+       return atomic_notifier_chain_register(&ipc_notifier, nb);
+}
+EXPORT_SYMBOL_GPL(pl320_ipc_register_notifier);
+
+int pl320_ipc_unregister_notifier(struct notifier_block *nb)
+{
+       return atomic_notifier_chain_unregister(&ipc_notifier, nb);
+}
+EXPORT_SYMBOL_GPL(pl320_ipc_unregister_notifier);
+
+static int __init pl320_probe(struct amba_device *adev,
+                               const struct amba_id *id)
+{
+       int ret;
+
+       ipc_base = ioremap(adev->res.start, resource_size(&adev->res));
+       if (ipc_base == NULL)
+               return -ENOMEM;
+
+       __raw_writel(0, ipc_base + IPCMxSEND(IPC_TX_MBOX));
+
+       ipc_irq = adev->irq[0];
+       ret = request_irq(ipc_irq, ipc_handler, 0, dev_name(&adev->dev), NULL);
+       if (ret < 0)
+               goto err;
+
+       /* Init slow mailbox */
+       __raw_writel(CHAN_MASK(A9_SOURCE),
+                       ipc_base + IPCMxSOURCE(IPC_TX_MBOX));
+       __raw_writel(CHAN_MASK(M3_SOURCE),
+                       ipc_base + IPCMxDSET(IPC_TX_MBOX));
+       __raw_writel(CHAN_MASK(M3_SOURCE) | CHAN_MASK(A9_SOURCE),
+                    ipc_base + IPCMxMSET(IPC_TX_MBOX));
+
+       /* Init receive mailbox */
+       __raw_writel(CHAN_MASK(M3_SOURCE),
+                       ipc_base + IPCMxSOURCE(IPC_RX_MBOX));
+       __raw_writel(CHAN_MASK(A9_SOURCE),
+                       ipc_base + IPCMxDSET(IPC_RX_MBOX));
+       __raw_writel(CHAN_MASK(M3_SOURCE) | CHAN_MASK(A9_SOURCE),
+                    ipc_base + IPCMxMSET(IPC_RX_MBOX));
+
+       return 0;
+err:
+       iounmap(ipc_base);
+       return ret;
+}
+
+static struct amba_id pl320_ids[] = {
+       {
+               .id     = 0x00041320,
+               .mask   = 0x000fffff,
+       },
+       { 0, 0 },
+};
+
+static struct amba_driver pl320_driver = {
+       .drv = {
+               .name   = "pl320",
+       },
+       .id_table       = pl320_ids,
+       .probe          = pl320_probe,
+};
+
+static int __init ipc_init(void)
+{
+       return amba_driver_register(&pl320_driver);
+}
+module_init(ipc_init);
diff --git a/include/linux/mailbox.h b/include/linux/mailbox.h
new file mode 100644 (file)
index 0000000..5161f63
--- /dev/null
@@ -0,0 +1,17 @@
+/*
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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/>.
+ */
+
+int pl320_ipc_transmit(u32 *data);
+int pl320_ipc_register_notifier(struct notifier_block *nb);
+int pl320_ipc_unregister_notifier(struct notifier_block *nb);