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mailbox.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;

00046 struct omap_mbox2_fifo {
      unsigned long msg;
      unsigned long fifo_stat;
      unsigned long msg_stat;
};

00052 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, resource_size(res));
      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");

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