Date:	Wed, 14 Nov 2012 08:03:07 -0600
From:	Rob Herring <rob.herring@...xeda.com>
To:	Mark Langsdorf <mark.langsdorf@...xeda.com>
CC:	linux-kernel@...r.kernel.org, cpufreq@...r.kernel.org,
	linux-pm@...r.kernel.org
Subject: Re: [PATCH 4/6 v4] arm highbank: add support for pl320 IPC

On 11/07/2012 12:32 PM, Mark Langsdorf wrote:
> From: Rob Herring <rob.herring@...xeda.com>
> 
> 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@...xeda.com>
> Signed-off-by: Rob Herring <rob.herring@...xeda.com>
> ---
> 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);
> 
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists