568 lines
15 KiB
C
568 lines
15 KiB
C
/*
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* Copyright (C) ST-Ericsson SA 2010
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* Author: Stefan Nilsson <stefan.xk.nilsson@stericsson.com> for ST-Ericsson.
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* Author: Martin Persson <martin.persson@stericsson.com> for ST-Ericsson.
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* License terms: GNU General Public License (GPL), version 2.
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*/
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/*
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* Mailbox nomenclature:
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*
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* APE MODEM
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* mbox pairX
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* ..........................
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* . .
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* . peer .
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* . send ---- .
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* . --> | | .
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* . | | .
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* . ---- .
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* . .
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* . local .
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* . rec ---- .
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* . | | <-- .
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* . | | .
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* . ---- .
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* .........................
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*/
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/device.h>
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#include <linux/interrupt.h>
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#include <linux/spinlock.h>
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#include <linux/errno.h>
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#include <linux/io.h>
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#include <linux/irq.h>
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#include <linux/platform_device.h>
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#include <linux/debugfs.h>
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#include <linux/seq_file.h>
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#include <linux/completion.h>
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#include <mach/mbox-db5500.h>
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#define MBOX_NAME "mbox"
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#define MBOX_FIFO_DATA 0x000
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#define MBOX_FIFO_ADD 0x004
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#define MBOX_FIFO_REMOVE 0x008
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#define MBOX_FIFO_THRES_FREE 0x00C
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#define MBOX_FIFO_THRES_OCCUP 0x010
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#define MBOX_FIFO_STATUS 0x014
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#define MBOX_DISABLE_IRQ 0x4
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#define MBOX_ENABLE_IRQ 0x0
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#define MBOX_LATCH 1
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/* Global list of all mailboxes */
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static struct list_head mboxs = LIST_HEAD_INIT(mboxs);
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static struct mbox *get_mbox_with_id(u8 id)
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{
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u8 i;
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struct list_head *pos = &mboxs;
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for (i = 0; i <= id; i++)
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pos = pos->next;
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return (struct mbox *) list_entry(pos, struct mbox, list);
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}
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int mbox_send(struct mbox *mbox, u32 mbox_msg, bool block)
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{
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int res = 0;
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spin_lock(&mbox->lock);
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dev_dbg(&(mbox->pdev->dev),
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"About to buffer 0x%X to mailbox 0x%X."
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" ri = %d, wi = %d\n",
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mbox_msg, (u32)mbox, mbox->read_index,
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mbox->write_index);
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/* Check if write buffer is full */
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while (((mbox->write_index + 1) % MBOX_BUF_SIZE) == mbox->read_index) {
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if (!block) {
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dev_dbg(&(mbox->pdev->dev),
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"Buffer full in non-blocking call! "
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"Returning -ENOMEM!\n");
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res = -ENOMEM;
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goto exit;
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}
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spin_unlock(&mbox->lock);
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dev_dbg(&(mbox->pdev->dev),
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"Buffer full in blocking call! Sleeping...\n");
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mbox->client_blocked = 1;
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wait_for_completion(&mbox->buffer_available);
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dev_dbg(&(mbox->pdev->dev),
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"Blocking send was woken up! Trying again...\n");
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spin_lock(&mbox->lock);
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}
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mbox->buffer[mbox->write_index] = mbox_msg;
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mbox->write_index = (mbox->write_index + 1) % MBOX_BUF_SIZE;
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/*
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* Indicate that we want an IRQ as soon as there is a slot
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* in the FIFO
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*/
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writel(MBOX_ENABLE_IRQ, mbox->virtbase_peer + MBOX_FIFO_THRES_FREE);
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exit:
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spin_unlock(&mbox->lock);
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return res;
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}
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EXPORT_SYMBOL(mbox_send);
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#if defined(CONFIG_DEBUG_FS)
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/*
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* Expected input: <value> <nbr sends>
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* Example: "echo 0xdeadbeef 4 > mbox-node" sends 0xdeadbeef 4 times
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*/
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static ssize_t mbox_write_fifo(struct device *dev,
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struct device_attribute *attr,
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const char *buf,
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size_t count)
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{
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unsigned long mbox_mess;
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unsigned long nbr_sends;
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unsigned long i;
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char int_buf[16];
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char *token;
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char *val;
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struct mbox *mbox = (struct mbox *) dev->platform_data;
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strncpy((char *) &int_buf, buf, sizeof(int_buf));
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token = (char *) &int_buf;
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/* Parse message */
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val = strsep(&token, " ");
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if ((val == NULL) || (strict_strtoul(val, 16, &mbox_mess) != 0))
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mbox_mess = 0xDEADBEEF;
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val = strsep(&token, " ");
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if ((val == NULL) || (strict_strtoul(val, 10, &nbr_sends) != 0))
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nbr_sends = 1;
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dev_dbg(dev, "Will write 0x%lX %ld times using data struct at 0x%X\n",
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mbox_mess, nbr_sends, (u32) mbox);
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for (i = 0; i < nbr_sends; i++)
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mbox_send(mbox, mbox_mess, true);
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return count;
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}
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static ssize_t mbox_read_fifo(struct device *dev,
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struct device_attribute *attr,
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char *buf)
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{
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int mbox_value;
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struct mbox *mbox = (struct mbox *) dev->platform_data;
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if ((readl(mbox->virtbase_local + MBOX_FIFO_STATUS) & 0x7) <= 0)
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return sprintf(buf, "Mailbox is empty\n");
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mbox_value = readl(mbox->virtbase_local + MBOX_FIFO_DATA);
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writel(MBOX_LATCH, (mbox->virtbase_local + MBOX_FIFO_REMOVE));
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return sprintf(buf, "0x%X\n", mbox_value);
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}
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static DEVICE_ATTR(fifo, S_IWUGO | S_IRUGO, mbox_read_fifo, mbox_write_fifo);
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static int mbox_show(struct seq_file *s, void *data)
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{
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struct list_head *pos;
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u8 mbox_index = 0;
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list_for_each(pos, &mboxs) {
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struct mbox *m =
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(struct mbox *) list_entry(pos, struct mbox, list);
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if (m == NULL) {
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seq_printf(s,
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"Unable to retrieve mailbox %d\n",
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mbox_index);
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continue;
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}
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spin_lock(&m->lock);
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if ((m->virtbase_peer == NULL) || (m->virtbase_local == NULL)) {
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seq_printf(s, "MAILBOX %d not setup or corrupt\n",
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mbox_index);
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spin_unlock(&m->lock);
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continue;
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}
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seq_printf(s,
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"===========================\n"
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" MAILBOX %d\n"
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" PEER MAILBOX DUMP\n"
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"---------------------------\n"
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"FIFO: 0x%X (%d)\n"
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"Free Threshold: 0x%.2X (%d)\n"
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"Occupied Threshold: 0x%.2X (%d)\n"
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"Status: 0x%.2X (%d)\n"
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" Free spaces (ot): %d (%d)\n"
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" Occup spaces (ot): %d (%d)\n"
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"===========================\n"
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" LOCAL MAILBOX DUMP\n"
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"---------------------------\n"
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"FIFO: 0x%.X (%d)\n"
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"Free Threshold: 0x%.2X (%d)\n"
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"Occupied Threshold: 0x%.2X (%d)\n"
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"Status: 0x%.2X (%d)\n"
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" Free spaces (ot): %d (%d)\n"
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" Occup spaces (ot): %d (%d)\n"
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"===========================\n"
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"write_index: %d\n"
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"read_index : %d\n"
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"===========================\n"
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"\n",
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mbox_index,
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readl(m->virtbase_peer + MBOX_FIFO_DATA),
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readl(m->virtbase_peer + MBOX_FIFO_DATA),
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readl(m->virtbase_peer + MBOX_FIFO_THRES_FREE),
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readl(m->virtbase_peer + MBOX_FIFO_THRES_FREE),
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readl(m->virtbase_peer + MBOX_FIFO_THRES_OCCUP),
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readl(m->virtbase_peer + MBOX_FIFO_THRES_OCCUP),
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readl(m->virtbase_peer + MBOX_FIFO_STATUS),
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readl(m->virtbase_peer + MBOX_FIFO_STATUS),
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(readl(m->virtbase_peer + MBOX_FIFO_STATUS) >> 4) & 0x7,
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(readl(m->virtbase_peer + MBOX_FIFO_STATUS) >> 7) & 0x1,
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(readl(m->virtbase_peer + MBOX_FIFO_STATUS) >> 0) & 0x7,
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(readl(m->virtbase_peer + MBOX_FIFO_STATUS) >> 3) & 0x1,
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readl(m->virtbase_local + MBOX_FIFO_DATA),
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readl(m->virtbase_local + MBOX_FIFO_DATA),
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readl(m->virtbase_local + MBOX_FIFO_THRES_FREE),
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readl(m->virtbase_local + MBOX_FIFO_THRES_FREE),
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readl(m->virtbase_local + MBOX_FIFO_THRES_OCCUP),
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readl(m->virtbase_local + MBOX_FIFO_THRES_OCCUP),
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readl(m->virtbase_local + MBOX_FIFO_STATUS),
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readl(m->virtbase_local + MBOX_FIFO_STATUS),
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(readl(m->virtbase_local + MBOX_FIFO_STATUS) >> 4) & 0x7,
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(readl(m->virtbase_local + MBOX_FIFO_STATUS) >> 7) & 0x1,
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(readl(m->virtbase_local + MBOX_FIFO_STATUS) >> 0) & 0x7,
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(readl(m->virtbase_local + MBOX_FIFO_STATUS) >> 3) & 0x1,
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m->write_index, m->read_index);
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mbox_index++;
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spin_unlock(&m->lock);
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}
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return 0;
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}
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static int mbox_open(struct inode *inode, struct file *file)
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{
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return single_open(file, mbox_show, NULL);
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}
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static const struct file_operations mbox_operations = {
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.owner = THIS_MODULE,
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.open = mbox_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = single_release,
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};
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#endif
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static irqreturn_t mbox_irq(int irq, void *arg)
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{
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u32 mbox_value;
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int nbr_occup;
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int nbr_free;
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struct mbox *mbox = (struct mbox *) arg;
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spin_lock(&mbox->lock);
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dev_dbg(&(mbox->pdev->dev),
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"mbox IRQ [%d] received. ri = %d, wi = %d\n",
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irq, mbox->read_index, mbox->write_index);
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/*
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* Check if we have any outgoing messages, and if there is space for
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* them in the FIFO.
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*/
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if (mbox->read_index != mbox->write_index) {
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/*
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* Check by reading FREE for LOCAL since that indicates
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* OCCUP for PEER
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*/
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nbr_free = (readl(mbox->virtbase_local + MBOX_FIFO_STATUS)
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>> 4) & 0x7;
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dev_dbg(&(mbox->pdev->dev),
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"Status indicates %d empty spaces in the FIFO!\n",
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nbr_free);
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while ((nbr_free > 0) &&
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(mbox->read_index != mbox->write_index)) {
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/* Write the message and latch it into the FIFO */
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writel(mbox->buffer[mbox->read_index],
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(mbox->virtbase_peer + MBOX_FIFO_DATA));
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writel(MBOX_LATCH,
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(mbox->virtbase_peer + MBOX_FIFO_ADD));
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dev_dbg(&(mbox->pdev->dev),
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"Wrote message 0x%X to addr 0x%X\n",
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mbox->buffer[mbox->read_index],
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(u32) (mbox->virtbase_peer + MBOX_FIFO_DATA));
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nbr_free--;
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mbox->read_index =
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(mbox->read_index + 1) % MBOX_BUF_SIZE;
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}
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/*
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* Check if we still want IRQ:s when there is free
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* space to send
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*/
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if (mbox->read_index != mbox->write_index) {
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dev_dbg(&(mbox->pdev->dev),
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"Still have messages to send, but FIFO full. "
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"Request IRQ again!\n");
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writel(MBOX_ENABLE_IRQ,
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mbox->virtbase_peer + MBOX_FIFO_THRES_FREE);
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} else {
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dev_dbg(&(mbox->pdev->dev),
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"No more messages to send. "
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"Do not request IRQ again!\n");
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writel(MBOX_DISABLE_IRQ,
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mbox->virtbase_peer + MBOX_FIFO_THRES_FREE);
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}
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/*
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* Check if we can signal any blocked clients that it is OK to
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* start buffering again
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*/
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if (mbox->client_blocked &&
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(((mbox->write_index + 1) % MBOX_BUF_SIZE)
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!= mbox->read_index)) {
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dev_dbg(&(mbox->pdev->dev),
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"Waking up blocked client\n");
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complete(&mbox->buffer_available);
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mbox->client_blocked = 0;
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}
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}
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/* Check if we have any incoming messages */
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nbr_occup = readl(mbox->virtbase_local + MBOX_FIFO_STATUS) & 0x7;
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if (nbr_occup == 0)
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goto exit;
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if (mbox->cb == NULL) {
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dev_dbg(&(mbox->pdev->dev), "No receive callback registered, "
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"leaving %d incoming messages in fifo!\n", nbr_occup);
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goto exit;
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}
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/* Read and acknowledge the message */
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mbox_value = readl(mbox->virtbase_local + MBOX_FIFO_DATA);
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writel(MBOX_LATCH, (mbox->virtbase_local + MBOX_FIFO_REMOVE));
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/* Notify consumer of new mailbox message */
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dev_dbg(&(mbox->pdev->dev), "Calling callback for message 0x%X!\n",
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mbox_value);
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mbox->cb(mbox_value, mbox->client_data);
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exit:
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dev_dbg(&(mbox->pdev->dev), "Exit mbox IRQ. ri = %d, wi = %d\n",
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mbox->read_index, mbox->write_index);
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spin_unlock(&mbox->lock);
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return IRQ_HANDLED;
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}
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/* Setup is executed once for each mbox pair */
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struct mbox *mbox_setup(u8 mbox_id, mbox_recv_cb_t *mbox_cb, void *priv)
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{
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struct resource *resource;
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int irq;
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int res;
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struct mbox *mbox;
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mbox = get_mbox_with_id(mbox_id);
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if (mbox == NULL) {
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dev_err(&(mbox->pdev->dev), "Incorrect mailbox id: %d!\n",
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mbox_id);
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goto exit;
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}
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/*
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* Check if mailbox has been allocated to someone else,
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* otherwise allocate it
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*/
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if (mbox->allocated) {
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dev_err(&(mbox->pdev->dev), "Mailbox number %d is busy!\n",
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mbox_id);
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mbox = NULL;
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goto exit;
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}
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mbox->allocated = true;
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dev_dbg(&(mbox->pdev->dev), "Initiating mailbox number %d: 0x%X...\n",
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mbox_id, (u32)mbox);
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mbox->client_data = priv;
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mbox->cb = mbox_cb;
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/* Get addr for peer mailbox and ioremap it */
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resource = platform_get_resource_byname(mbox->pdev,
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IORESOURCE_MEM,
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"mbox_peer");
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if (resource == NULL) {
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dev_err(&(mbox->pdev->dev),
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"Unable to retrieve mbox peer resource\n");
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mbox = NULL;
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goto exit;
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}
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dev_dbg(&(mbox->pdev->dev),
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"Resource name: %s start: 0x%X, end: 0x%X\n",
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resource->name, resource->start, resource->end);
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mbox->virtbase_peer =
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ioremap(resource->start, resource->end - resource->start);
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if (!mbox->virtbase_peer) {
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dev_err(&(mbox->pdev->dev), "Unable to ioremap peer mbox\n");
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mbox = NULL;
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goto exit;
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}
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dev_dbg(&(mbox->pdev->dev),
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"ioremapped peer physical: (0x%X-0x%X) to virtual: 0x%X\n",
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resource->start, resource->end, (u32) mbox->virtbase_peer);
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/* Get addr for local mailbox and ioremap it */
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resource = platform_get_resource_byname(mbox->pdev,
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IORESOURCE_MEM,
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"mbox_local");
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if (resource == NULL) {
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dev_err(&(mbox->pdev->dev),
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"Unable to retrieve mbox local resource\n");
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mbox = NULL;
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goto exit;
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}
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dev_dbg(&(mbox->pdev->dev),
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"Resource name: %s start: 0x%X, end: 0x%X\n",
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resource->name, resource->start, resource->end);
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mbox->virtbase_local =
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ioremap(resource->start, resource->end - resource->start);
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if (!mbox->virtbase_local) {
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dev_err(&(mbox->pdev->dev), "Unable to ioremap local mbox\n");
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mbox = NULL;
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goto exit;
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}
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dev_dbg(&(mbox->pdev->dev),
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"ioremapped local physical: (0x%X-0x%X) to virtual: 0x%X\n",
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resource->start, resource->end, (u32) mbox->virtbase_peer);
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init_completion(&mbox->buffer_available);
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mbox->client_blocked = 0;
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/* Get IRQ for mailbox and allocate it */
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irq = platform_get_irq_byname(mbox->pdev, "mbox_irq");
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if (irq < 0) {
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dev_err(&(mbox->pdev->dev),
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"Unable to retrieve mbox irq resource\n");
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mbox = NULL;
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goto exit;
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}
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dev_dbg(&(mbox->pdev->dev), "Allocating irq %d...\n", irq);
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res = request_irq(irq, mbox_irq, 0, mbox->name, (void *) mbox);
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if (res < 0) {
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dev_err(&(mbox->pdev->dev),
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"Unable to allocate mbox irq %d\n", irq);
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mbox = NULL;
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goto exit;
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}
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/* Set up mailbox to not launch IRQ on free space in mailbox */
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writel(MBOX_DISABLE_IRQ, mbox->virtbase_peer + MBOX_FIFO_THRES_FREE);
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/*
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* Set up mailbox to launch IRQ on new message if we have
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* a callback set. If not, do not raise IRQ, but keep message
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* in FIFO for manual retrieval
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*/
|
|
if (mbox_cb != NULL)
|
|
writel(MBOX_ENABLE_IRQ,
|
|
mbox->virtbase_local + MBOX_FIFO_THRES_OCCUP);
|
|
else
|
|
writel(MBOX_DISABLE_IRQ,
|
|
mbox->virtbase_local + MBOX_FIFO_THRES_OCCUP);
|
|
|
|
#if defined(CONFIG_DEBUG_FS)
|
|
res = device_create_file(&(mbox->pdev->dev), &dev_attr_fifo);
|
|
if (res != 0)
|
|
dev_warn(&(mbox->pdev->dev),
|
|
"Unable to create mbox sysfs entry");
|
|
|
|
(void) debugfs_create_file("mbox", S_IFREG | S_IRUGO, NULL,
|
|
NULL, &mbox_operations);
|
|
#endif
|
|
|
|
dev_info(&(mbox->pdev->dev),
|
|
"Mailbox driver with index %d initated!\n", mbox_id);
|
|
|
|
exit:
|
|
return mbox;
|
|
}
|
|
EXPORT_SYMBOL(mbox_setup);
|
|
|
|
|
|
int __init mbox_probe(struct platform_device *pdev)
|
|
{
|
|
struct mbox local_mbox;
|
|
struct mbox *mbox;
|
|
int res = 0;
|
|
dev_dbg(&(pdev->dev), "Probing mailbox (pdev = 0x%X)...\n", (u32) pdev);
|
|
|
|
memset(&local_mbox, 0x0, sizeof(struct mbox));
|
|
|
|
/* Associate our mbox data with the platform device */
|
|
res = platform_device_add_data(pdev,
|
|
(void *) &local_mbox,
|
|
sizeof(struct mbox));
|
|
if (res != 0) {
|
|
dev_err(&(pdev->dev),
|
|
"Unable to allocate driver platform data!\n");
|
|
goto exit;
|
|
}
|
|
|
|
mbox = (struct mbox *) pdev->dev.platform_data;
|
|
mbox->pdev = pdev;
|
|
mbox->write_index = 0;
|
|
mbox->read_index = 0;
|
|
|
|
INIT_LIST_HEAD(&(mbox->list));
|
|
list_add_tail(&(mbox->list), &mboxs);
|
|
|
|
sprintf(mbox->name, "%s", MBOX_NAME);
|
|
spin_lock_init(&mbox->lock);
|
|
|
|
dev_info(&(pdev->dev), "Mailbox driver loaded\n");
|
|
|
|
exit:
|
|
return res;
|
|
}
|
|
|
|
static struct platform_driver mbox_driver = {
|
|
.driver = {
|
|
.name = MBOX_NAME,
|
|
.owner = THIS_MODULE,
|
|
},
|
|
};
|
|
|
|
static int __init mbox_init(void)
|
|
{
|
|
return platform_driver_probe(&mbox_driver, mbox_probe);
|
|
}
|
|
|
|
module_init(mbox_init);
|
|
|
|
void __exit mbox_exit(void)
|
|
{
|
|
platform_driver_unregister(&mbox_driver);
|
|
}
|
|
|
|
module_exit(mbox_exit);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_DESCRIPTION("MBOX driver");
|