Re: [PATCH 4/6 v4] arm highbank: add support for pl320 IPC

From: Rob Herring
Date: Wed Nov 14 2012 - 09:03:00 EST

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On 11/07/2012 12:32 PM, Mark Langsdorf wrote:
> From: Rob Herring <rob.herring@xxxxxxxxxxx>
>
> 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@xxxxxxxxxxx>
> Signed-off-by: Rob Herring <rob.herring@xxxxxxxxxxx>
> ---
> Changes from v3, v2
> None
> Changes from v1
> Removed erroneous changes for cpufreq Kconfig
>
> arch/arm/include/asm/pl320-ipc.h | 20 ++

asm/hardware/ is probably more appropriate.

> arch/arm/mach-highbank/Makefile | 2 +
> arch/arm/mach-highbank/include/mach/pl320-ipc.h | 20 ++

Need to delete this file.

> arch/arm/mach-highbank/pl320-ipc.c | 232 ++++++++++++++++++++++++
> 4 files changed, 274 insertions(+)
> create mode 100644 arch/arm/include/asm/pl320-ipc.h
> create mode 100644 arch/arm/mach-highbank/include/mach/pl320-ipc.h
> create mode 100644 arch/arm/mach-highbank/pl320-ipc.c
>
> diff --git a/arch/arm/include/asm/pl320-ipc.h b/arch/arm/include/asm/pl320-ipc.h
> new file mode 100644
> index 0000000..a0e58ee
> --- /dev/null
> +++ b/arch/arm/include/asm/pl320-ipc.h
> @@ -0,0 +1,20 @@
> +/*
> + * Copyright 2010 Calxeda, Inc.

Update copyright.

> + *
> + * 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 ipc_call_fast(u32 *data);

We should get rid of fast and slow channels and just have a single tx
channel as it is all the same and we don't use the fast channel.

> +int ipc_call_slow(u32 *data);
> +
> +extern int pl320_ipc_register_notifier(struct notifier_block *nb);
> +extern int pl320_ipc_unregister_notifier(struct notifier_block *nb);
> diff --git a/arch/arm/mach-highbank/Makefile b/arch/arm/mach-highbank/Makefile
> index 3ec8bdd..b894708 100644
> --- a/arch/arm/mach-highbank/Makefile
> +++ b/arch/arm/mach-highbank/Makefile
> @@ -7,3 +7,5 @@ obj-$(CONFIG_DEBUG_HIGHBANK_UART) += lluart.o
> obj-$(CONFIG_SMP) += platsmp.o
> obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o
> obj-$(CONFIG_PM_SLEEP) += pm.o
> +
> +obj-y += pl320-ipc.o
> diff --git a/arch/arm/mach-highbank/include/mach/pl320-ipc.h b/arch/arm/mach-highbank/include/mach/pl320-ipc.h
> new file mode 100644
> index 0000000..a0e58ee
> --- /dev/null
> +++ b/arch/arm/mach-highbank/include/mach/pl320-ipc.h
> @@ -0,0 +1,20 @@
> +/*
> + * Copyright 2010 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/>.
> + */
> +int ipc_call_fast(u32 *data);
> +int ipc_call_slow(u32 *data);
> +
> +extern int pl320_ipc_register_notifier(struct notifier_block *nb);
> +extern int pl320_ipc_unregister_notifier(struct notifier_block *nb);
> diff --git a/arch/arm/mach-highbank/pl320-ipc.c b/arch/arm/mach-highbank/pl320-ipc.c
> new file mode 100644
> index 0000000..0eb92e4
> --- /dev/null
> +++ b/arch/arm/mach-highbank/pl320-ipc.c
> @@ -0,0 +1,232 @@
> +/*
> + * 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 <asm/pl320-ipc.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_FAST_MBOX 0
> +#define IPC_SLOW_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_SPINLOCK(ipc_m0_lock);
> +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];
> +}
> +
> +/* non-blocking implementation from the A9 side, interrupt safe in theory */
> +int ipc_call_fast(u32 *data)
> +{
> + int timeout, ret;
> +
> + spin_lock(&ipc_m0_lock);
> +
> + __ipc_send(IPC_FAST_MBOX, data);
> +
> + for (timeout = 500; timeout > 0; timeout--) {
> + if (__raw_readl(ipc_base + IPCMxSEND(IPC_FAST_MBOX)) == 0x2)
> + break;
> + udelay(100);
> + }
> + if (timeout == 0) {
> + ret = -ETIMEDOUT;
> + goto out;
> + }
> +
> + ret = __ipc_rcv(IPC_FAST_MBOX, data);
> +out:
> + __raw_writel(0, ipc_base + IPCMxSEND(IPC_FAST_MBOX));
> + spin_unlock(&ipc_m0_lock);
> + return ret;
> +}
> +EXPORT_SYMBOL(ipc_call_fast);
> +
> +/* blocking implmentation from the A9 side, not usuable in interrupts! */
> +int ipc_call_slow(u32 *data)
> +{
> + int ret;
> +
> + mutex_lock(&ipc_m1_lock);
> +
> + init_completion(&ipc_completion);
> + __ipc_send(IPC_SLOW_MBOX, data);
> + ret = wait_for_completion_timeout(&ipc_completion,
> + msecs_to_jiffies(1000));
> + if (ret == 0) {
> + ret = -ETIMEDOUT;
> + goto out;
> + }
> +
> + ret = __ipc_rcv(IPC_SLOW_MBOX, data);
> +out:
> + mutex_unlock(&ipc_m1_lock);
> + return ret;
> +}
> +EXPORT_SYMBOL(ipc_call_slow);
> +
> +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_SLOW_MBOX)) {
> + __raw_writel(0, ipc_base + IPCMxSEND(IPC_SLOW_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);
> +}
> +
> +int pl320_ipc_unregister_notifier(struct notifier_block *nb)
> +{
> + return atomic_notifier_chain_unregister(&ipc_notifier, nb);
> +}
> +
> +static int __devinit 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_FAST_MBOX));
> + __raw_writel(0, ipc_base + IPCMxSEND(IPC_SLOW_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 fast mailbox */
> + __raw_writel(CHAN_MASK(A9_SOURCE),
> + ipc_base + IPCMxSOURCE(IPC_FAST_MBOX));
> + set_destination(M3_SOURCE, IPC_FAST_MBOX);
> +
> + /* Init slow mailbox */
> + __raw_writel(CHAN_MASK(A9_SOURCE),
> + ipc_base + IPCMxSOURCE(IPC_SLOW_MBOX));
> + __raw_writel(CHAN_MASK(M3_SOURCE),
> + ipc_base + IPCMxDSET(IPC_SLOW_MBOX));
> + __raw_writel(CHAN_MASK(M3_SOURCE) | CHAN_MASK(A9_SOURCE),
> + ipc_base + IPCMxMSET(IPC_SLOW_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);
>
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