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