From: Linus Walleij Date: Mon, 27 Sep 2010 21:11:57 +0000 (+0100) Subject: ARM: 6415/1: ux500: DB5500 mailbox driver X-Git-Tag: v2.6.37-rc1~184^2~7^8~4 X-Git-Url: http://bbs.cooldavid.org/git/?a=commitdiff_plain;h=38cdfe06630a109a7a38b70c3cd208defd9f5711;p=net-next-2.6.git ARM: 6415/1: ux500: DB5500 mailbox driver This is a driver for the mailboxes used to communicate with the DB5500 modem portions. Signed-off-by: Stefan Nilsson XK Signed-off-by: Linus Walleij Signed-off-by: Russell King --- diff --git a/arch/arm/mach-ux500/include/mach/mbox.h b/arch/arm/mach-ux500/include/mach/mbox.h new file mode 100644 index 00000000000..7f9da4d2fbd --- /dev/null +++ b/arch/arm/mach-ux500/include/mach/mbox.h @@ -0,0 +1,88 @@ +/* + * Copyright (C) ST-Ericsson SA 2010 + * Author: Stefan Nilsson for ST-Ericsson. + * Author: Martin Persson for ST-Ericsson. + * License terms: GNU General Public License (GPL), version 2. + */ + +#ifndef __INC_STE_MBOX_H +#define __INC_STE_MBOX_H + +#define MBOX_BUF_SIZE 16 +#define MBOX_NAME_SIZE 8 + +/** + * mbox_recv_cb_t - Definition of the mailbox callback. + * @mbox_msg: The mailbox message. + * @priv: The clients private data as specified in the call to mbox_setup. + * + * This function will be called upon reception of new mailbox messages. + */ +typedef void mbox_recv_cb_t (u32 mbox_msg, void *priv); + +/** + * struct mbox - Mailbox instance struct + * @list: Linked list head. + * @pdev: Pointer to device struct. + * @cb: Callback function. Will be called + * when new data is received. + * @client_data: Clients private data. Will be sent back + * in the callback function. + * @virtbase_peer: Virtual address for outgoing mailbox. + * @virtbase_local: Virtual address for incoming mailbox. + * @buffer: Then internal queue for outgoing messages. + * @name: Name of this mailbox. + * @buffer_available: Completion variable to achieve "blocking send". + * This variable will be signaled when there is + * internal buffer space available. + * @client_blocked: To keep track if any client is currently + * blocked. + * @lock: Spinlock to protect this mailbox instance. + * @write_index: Index in internal buffer to write to. + * @read_index: Index in internal buffer to read from. + * @allocated: Indicates whether this particular mailbox + * id has been allocated by someone. + */ +struct mbox { + struct list_head list; + struct platform_device *pdev; + mbox_recv_cb_t *cb; + void *client_data; + void __iomem *virtbase_peer; + void __iomem *virtbase_local; + u32 buffer[MBOX_BUF_SIZE]; + char name[MBOX_NAME_SIZE]; + struct completion buffer_available; + u8 client_blocked; + spinlock_t lock; + u8 write_index; + u8 read_index; + bool allocated; +}; + +/** + * mbox_setup - Set up a mailbox and return its instance. + * @mbox_id: The ID number of the mailbox. 0 or 1 for modem CPU, + * 2 for modem DSP. + * @mbox_cb: Pointer to the callback function to be called when a new message + * is received. + * @priv: Client user data which will be returned in the callback. + * + * Returns a mailbox instance to be specified in subsequent calls to mbox_send. + */ +struct mbox *mbox_setup(u8 mbox_id, mbox_recv_cb_t *mbox_cb, void *priv); + +/** + * mbox_send - Send a mailbox message. + * @mbox: Mailbox instance (returned by mbox_setup) + * @mbox_msg: The mailbox message to send. + * @block: Specifies whether this call will block until send is possible, + * or return an error if the mailbox buffer is full. + * + * Returns 0 on success or a negative error code on error. -ENOMEM indicates + * that the internal buffer is full and you have to try again later (or + * specify "block" in order to block until send is possible). + */ +int mbox_send(struct mbox *mbox, u32 mbox_msg, bool block); + +#endif /*INC_STE_MBOX_H*/ diff --git a/arch/arm/mach-ux500/mbox.c b/arch/arm/mach-ux500/mbox.c new file mode 100644 index 00000000000..63435389c54 --- /dev/null +++ b/arch/arm/mach-ux500/mbox.c @@ -0,0 +1,567 @@ +/* + * Copyright (C) ST-Ericsson SA 2010 + * Author: Stefan Nilsson for ST-Ericsson. + * Author: Martin Persson for ST-Ericsson. + * License terms: GNU General Public License (GPL), version 2. + */ + +/* + * Mailbox nomenclature: + * + * APE MODEM + * mbox pairX + * .......................... + * . . + * . peer . + * . send ---- . + * . --> | | . + * . | | . + * . ---- . + * . . + * . local . + * . rec ---- . + * . | | <-- . + * . | | . + * . ---- . + * ......................... + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#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: + * 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");