1 files changed, 567 insertions, 0 deletions

diff --git a/arch/arm/mach-ux500/mbox.c b/arch/arm/mach-ux500/mbox.c
new file mode 100644
index 000000000000..63435389c544
--- /dev/null
+++ b/arch/arm/mach-ux500/mbox.c
@@ -0,0 +1,567 @@
+/*
+ * 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");