android_kernel_motorola_sm6225/arch/arm/mach-omap2/mailbox.c
Hiroshi DOYU 8828880d09 omap: mailbox: Flush posted write when acking mailbox irq
The only way to flush posted write to L4 bus is to do a read back
of the same register right after the write.

This seems to be mostly needed in interrupt handlers to avoid
causing spurious interrupts.

The earlier fix has been to mark the L4 bus as strongly ordered
memory, which solves the problem, but causes performance penalties.

Similar to the fix, 03803a71041e3bc3c077f4e7b92f6ceaa9426df3

Signed-off-by: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2009-09-24 16:23:10 -07:00

377 lines
9 KiB
C

/*
* Mailbox reservation modules for OMAP2/3
*
* Copyright (C) 2006-2009 Nokia Corporation
* Written by: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
* and Paul Mundt
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/kernel.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <mach/mailbox.h>
#include <mach/irqs.h>
#define MAILBOX_REVISION 0x000
#define MAILBOX_SYSCONFIG 0x010
#define MAILBOX_SYSSTATUS 0x014
#define MAILBOX_MESSAGE(m) (0x040 + 4 * (m))
#define MAILBOX_FIFOSTATUS(m) (0x080 + 4 * (m))
#define MAILBOX_MSGSTATUS(m) (0x0c0 + 4 * (m))
#define MAILBOX_IRQSTATUS(u) (0x100 + 8 * (u))
#define MAILBOX_IRQENABLE(u) (0x104 + 8 * (u))
#define MAILBOX_IRQ_NEWMSG(u) (1 << (2 * (u)))
#define MAILBOX_IRQ_NOTFULL(u) (1 << (2 * (u) + 1))
/* SYSCONFIG: register bit definition */
#define AUTOIDLE (1 << 0)
#define SOFTRESET (1 << 1)
#define SMARTIDLE (2 << 3)
/* SYSSTATUS: register bit definition */
#define RESETDONE (1 << 0)
#define MBOX_REG_SIZE 0x120
#define MBOX_NR_REGS (MBOX_REG_SIZE / sizeof(u32))
static void __iomem *mbox_base;
struct omap_mbox2_fifo {
unsigned long msg;
unsigned long fifo_stat;
unsigned long msg_stat;
};
struct omap_mbox2_priv {
struct omap_mbox2_fifo tx_fifo;
struct omap_mbox2_fifo rx_fifo;
unsigned long irqenable;
unsigned long irqstatus;
u32 newmsg_bit;
u32 notfull_bit;
u32 ctx[MBOX_NR_REGS];
};
static struct clk *mbox_ick_handle;
static void omap2_mbox_enable_irq(struct omap_mbox *mbox,
omap_mbox_type_t irq);
static inline unsigned int mbox_read_reg(size_t ofs)
{
return __raw_readl(mbox_base + ofs);
}
static inline void mbox_write_reg(u32 val, size_t ofs)
{
__raw_writel(val, mbox_base + ofs);
}
/* Mailbox H/W preparations */
static int omap2_mbox_startup(struct omap_mbox *mbox)
{
u32 l;
unsigned long timeout;
mbox_ick_handle = clk_get(NULL, "mailboxes_ick");
if (IS_ERR(mbox_ick_handle)) {
pr_err("Can't get mailboxes_ick\n");
return -ENODEV;
}
clk_enable(mbox_ick_handle);
mbox_write_reg(SOFTRESET, MAILBOX_SYSCONFIG);
timeout = jiffies + msecs_to_jiffies(20);
do {
l = mbox_read_reg(MAILBOX_SYSSTATUS);
if (l & RESETDONE)
break;
} while (time_after(jiffies, timeout));
if (!(l & RESETDONE)) {
pr_err("Can't take mmu out of reset\n");
return -ENODEV;
}
l = mbox_read_reg(MAILBOX_REVISION);
pr_info("omap mailbox rev %d.%d\n", (l & 0xf0) >> 4, (l & 0x0f));
l = SMARTIDLE | AUTOIDLE;
mbox_write_reg(l, MAILBOX_SYSCONFIG);
omap2_mbox_enable_irq(mbox, IRQ_RX);
return 0;
}
static void omap2_mbox_shutdown(struct omap_mbox *mbox)
{
clk_disable(mbox_ick_handle);
clk_put(mbox_ick_handle);
}
/* Mailbox FIFO handle functions */
static mbox_msg_t omap2_mbox_fifo_read(struct omap_mbox *mbox)
{
struct omap_mbox2_fifo *fifo =
&((struct omap_mbox2_priv *)mbox->priv)->rx_fifo;
return (mbox_msg_t) mbox_read_reg(fifo->msg);
}
static void omap2_mbox_fifo_write(struct omap_mbox *mbox, mbox_msg_t msg)
{
struct omap_mbox2_fifo *fifo =
&((struct omap_mbox2_priv *)mbox->priv)->tx_fifo;
mbox_write_reg(msg, fifo->msg);
}
static int omap2_mbox_fifo_empty(struct omap_mbox *mbox)
{
struct omap_mbox2_fifo *fifo =
&((struct omap_mbox2_priv *)mbox->priv)->rx_fifo;
return (mbox_read_reg(fifo->msg_stat) == 0);
}
static int omap2_mbox_fifo_full(struct omap_mbox *mbox)
{
struct omap_mbox2_fifo *fifo =
&((struct omap_mbox2_priv *)mbox->priv)->tx_fifo;
return (mbox_read_reg(fifo->fifo_stat));
}
/* Mailbox IRQ handle functions */
static void omap2_mbox_enable_irq(struct omap_mbox *mbox,
omap_mbox_type_t irq)
{
struct omap_mbox2_priv *p = (struct omap_mbox2_priv *)mbox->priv;
u32 l, bit = (irq == IRQ_TX) ? p->notfull_bit : p->newmsg_bit;
l = mbox_read_reg(p->irqenable);
l |= bit;
mbox_write_reg(l, p->irqenable);
}
static void omap2_mbox_disable_irq(struct omap_mbox *mbox,
omap_mbox_type_t irq)
{
struct omap_mbox2_priv *p = (struct omap_mbox2_priv *)mbox->priv;
u32 l, bit = (irq == IRQ_TX) ? p->notfull_bit : p->newmsg_bit;
l = mbox_read_reg(p->irqenable);
l &= ~bit;
mbox_write_reg(l, p->irqenable);
}
static void omap2_mbox_ack_irq(struct omap_mbox *mbox,
omap_mbox_type_t irq)
{
struct omap_mbox2_priv *p = (struct omap_mbox2_priv *)mbox->priv;
u32 bit = (irq == IRQ_TX) ? p->notfull_bit : p->newmsg_bit;
mbox_write_reg(bit, p->irqstatus);
/* Flush posted write for irq status to avoid spurious interrupts */
mbox_read_reg(p->irqstatus);
}
static int omap2_mbox_is_irq(struct omap_mbox *mbox,
omap_mbox_type_t irq)
{
struct omap_mbox2_priv *p = (struct omap_mbox2_priv *)mbox->priv;
u32 bit = (irq == IRQ_TX) ? p->notfull_bit : p->newmsg_bit;
u32 enable = mbox_read_reg(p->irqenable);
u32 status = mbox_read_reg(p->irqstatus);
return (enable & status & bit);
}
static void omap2_mbox_save_ctx(struct omap_mbox *mbox)
{
int i;
struct omap_mbox2_priv *p = mbox->priv;
for (i = 0; i < MBOX_NR_REGS; i++) {
p->ctx[i] = mbox_read_reg(i * sizeof(u32));
dev_dbg(mbox->dev, "%s: [%02x] %08x\n", __func__,
i, p->ctx[i]);
}
}
static void omap2_mbox_restore_ctx(struct omap_mbox *mbox)
{
int i;
struct omap_mbox2_priv *p = mbox->priv;
for (i = 0; i < MBOX_NR_REGS; i++) {
mbox_write_reg(p->ctx[i], i * sizeof(u32));
dev_dbg(mbox->dev, "%s: [%02x] %08x\n", __func__,
i, p->ctx[i]);
}
}
static struct omap_mbox_ops omap2_mbox_ops = {
.type = OMAP_MBOX_TYPE2,
.startup = omap2_mbox_startup,
.shutdown = omap2_mbox_shutdown,
.fifo_read = omap2_mbox_fifo_read,
.fifo_write = omap2_mbox_fifo_write,
.fifo_empty = omap2_mbox_fifo_empty,
.fifo_full = omap2_mbox_fifo_full,
.enable_irq = omap2_mbox_enable_irq,
.disable_irq = omap2_mbox_disable_irq,
.ack_irq = omap2_mbox_ack_irq,
.is_irq = omap2_mbox_is_irq,
.save_ctx = omap2_mbox_save_ctx,
.restore_ctx = omap2_mbox_restore_ctx,
};
/*
* MAILBOX 0: ARM -> DSP,
* MAILBOX 1: ARM <- DSP.
* MAILBOX 2: ARM -> IVA,
* MAILBOX 3: ARM <- IVA.
*/
/* FIXME: the following structs should be filled automatically by the user id */
/* DSP */
static struct omap_mbox2_priv omap2_mbox_dsp_priv = {
.tx_fifo = {
.msg = MAILBOX_MESSAGE(0),
.fifo_stat = MAILBOX_FIFOSTATUS(0),
},
.rx_fifo = {
.msg = MAILBOX_MESSAGE(1),
.msg_stat = MAILBOX_MSGSTATUS(1),
},
.irqenable = MAILBOX_IRQENABLE(0),
.irqstatus = MAILBOX_IRQSTATUS(0),
.notfull_bit = MAILBOX_IRQ_NOTFULL(0),
.newmsg_bit = MAILBOX_IRQ_NEWMSG(1),
};
struct omap_mbox mbox_dsp_info = {
.name = "dsp",
.ops = &omap2_mbox_ops,
.priv = &omap2_mbox_dsp_priv,
};
EXPORT_SYMBOL(mbox_dsp_info);
#if defined(CONFIG_ARCH_OMAP2420) /* IVA */
static struct omap_mbox2_priv omap2_mbox_iva_priv = {
.tx_fifo = {
.msg = MAILBOX_MESSAGE(2),
.fifo_stat = MAILBOX_FIFOSTATUS(2),
},
.rx_fifo = {
.msg = MAILBOX_MESSAGE(3),
.msg_stat = MAILBOX_MSGSTATUS(3),
},
.irqenable = MAILBOX_IRQENABLE(3),
.irqstatus = MAILBOX_IRQSTATUS(3),
.notfull_bit = MAILBOX_IRQ_NOTFULL(2),
.newmsg_bit = MAILBOX_IRQ_NEWMSG(3),
};
static struct omap_mbox mbox_iva_info = {
.name = "iva",
.ops = &omap2_mbox_ops,
.priv = &omap2_mbox_iva_priv,
};
#endif
static int __devinit omap2_mbox_probe(struct platform_device *pdev)
{
struct resource *res;
int ret;
/* MBOX base */
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (unlikely(!res)) {
dev_err(&pdev->dev, "invalid mem resource\n");
return -ENODEV;
}
mbox_base = ioremap(res->start, res->end - res->start);
if (!mbox_base)
return -ENOMEM;
/* DSP or IVA2 IRQ */
ret = platform_get_irq(pdev, 0);
if (ret < 0) {
dev_err(&pdev->dev, "invalid irq resource\n");
goto err_dsp;
}
mbox_dsp_info.irq = ret;
ret = omap_mbox_register(&pdev->dev, &mbox_dsp_info);
if (ret)
goto err_dsp;
#if defined(CONFIG_ARCH_OMAP2420) /* IVA */
if (cpu_is_omap2420()) {
/* IVA IRQ */
res = platform_get_resource(pdev, IORESOURCE_IRQ, 1);
if (unlikely(!res)) {
dev_err(&pdev->dev, "invalid irq resource\n");
ret = -ENODEV;
goto err_iva1;
}
mbox_iva_info.irq = res->start;
ret = omap_mbox_register(&pdev->dev, &mbox_iva_info);
if (ret)
goto err_iva1;
}
#endif
return 0;
err_iva1:
omap_mbox_unregister(&mbox_dsp_info);
err_dsp:
iounmap(mbox_base);
return ret;
}
static int __devexit omap2_mbox_remove(struct platform_device *pdev)
{
#if defined(CONFIG_ARCH_OMAP2420)
omap_mbox_unregister(&mbox_iva_info);
#endif
omap_mbox_unregister(&mbox_dsp_info);
iounmap(mbox_base);
return 0;
}
static struct platform_driver omap2_mbox_driver = {
.probe = omap2_mbox_probe,
.remove = __devexit_p(omap2_mbox_remove),
.driver = {
.name = "omap2-mailbox",
},
};
static int __init omap2_mbox_init(void)
{
return platform_driver_register(&omap2_mbox_driver);
}
static void __exit omap2_mbox_exit(void)
{
platform_driver_unregister(&omap2_mbox_driver);
}
module_init(omap2_mbox_init);
module_exit(omap2_mbox_exit);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("omap mailbox: omap2/3 architecture specific functions");
MODULE_AUTHOR("Hiroshi DOYU <Hiroshi.DOYU@nokia.com>, Paul Mundt");
MODULE_ALIAS("platform:omap2-mailbox");