--- /dev/null
+/*
+ * 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.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 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");
git://bbs.cooldavid.org / net-next-2.6.git / commitdiff