ENGR00308060-3 mcc: add sema4 driver required by mcc

- add linux sema4 driver, that mandatory required by mcc.
  - use volatile types in sema4 structure
  - align the port definiton a9 is 1, m4 is 2.

Signed-off-by: Richard Zhu <r65037@freescale.com>

6 files changed, 504 insertions, 0 deletions

diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index 09b813479de5..39b6a58e8237 100644
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -627,5 +627,7 @@ config MXS_VIIM
           Support for access to MXS Virtual IIM device, most people should say N here.
 
 source "drivers/char/xillybus/Kconfig"
+
+source "drivers/char/imx_mcc/Kconfig"
 endmenu
 
diff --git a/drivers/char/Makefile b/drivers/char/Makefile
index e27e9fb1bfd7..5a4efdacc5e2 100644
--- a/drivers/char/Makefile
+++ b/drivers/char/Makefile
@@ -65,3 +65,4 @@ js-rtc-y = rtc.o
 
 obj-$(CONFIG_TILE_SROM)         += tile-srom.o
 obj-$(CONFIG_XILLYBUS)          += xillybus/
+obj-$(CONFIG_HAVE_IMX_MCC)      += imx_mcc/
diff --git a/drivers/char/imx_mcc/Kconfig b/drivers/char/imx_mcc/Kconfig
new file mode 100644
index 000000000000..1f892f8daccb
--- /dev/null
+++ b/drivers/char/imx_mcc/Kconfig
@@ -0,0 +1,9 @@
+#
+# imx mcc
+#
+
+config IMX_SEMA4
+        bool "IMX SEMA4 driver"
+        depends on SOC_IMX6SX
+        help
+          Support for IMX SEMA4 driver, most people should say N here.
diff --git a/drivers/char/imx_mcc/Makefile b/drivers/char/imx_mcc/Makefile
new file mode 100644
index 000000000000..4e7a91691b39
--- /dev/null
+++ b/drivers/char/imx_mcc/Makefile
@@ -0,0 +1,5 @@
+#
+# Makefile for imx mcc
+#
+#
+obj-$(CONFIG_IMX_SEMA4)         += imx_sema4.o
diff --git a/drivers/char/imx_mcc/imx_sema4.c b/drivers/char/imx_mcc/imx_sema4.c
new file mode 100644
index 000000000000..12d68a86dfe3
--- /dev/null
+++ b/drivers/char/imx_mcc/imx_sema4.c
@@ -0,0 +1,416 @@
+/*
+ * Copyright (C) 2014 Freescale Semiconductor, Inc.
+ */
+
+/*
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/wait.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/imx_sema4.h>
+
+static struct imx_sema4_mutex_device *imx6_sema4;
+
+/*!
+ * \brief mutex create function.
+ *
+ * This function allocates imx_sema4_mutex structure and returns a handle
+ * to it. The mutex to be created is identified by SEMA4 device number and mutex
+ * (gate) number. The handle is used to reference the created mutex in calls to
+ * other imx_sema4_mutex API functions. This function is to be called only
+ * once for each mutex.
+ *
+ * \param[in] dev_num     SEMA4 device (module) number.
+ * \param[in] mutex_num   Mutex (gate) number.
+ *
+ * \return NULL (Failure.)
+ * \return imx_sema4_mutex (Success.)
+ */
+struct imx_sema4_mutex *
+imx_sema4_mutex_create(u32 dev_num, u32 mutex_num)
+{
+        struct imx_sema4_mutex *mutex_ptr = NULL;
+
+        if ((mutex_num > SEMA4_NUM_GATES) || dev_num >= SEMA4_NUM_DEVICES)
+                goto out;
+
+        if (imx6_sema4->cpine_val & (1 < mutex_num)) {
+                pr_err("Error: requiring a allocated sema4.\n");
+                pr_err("mutex_num %d cpine_val 0x%08x.\n",
+                                mutex_num, imx6_sema4->cpine_val);
+        }
+        mutex_ptr = kzalloc(sizeof(*mutex_ptr), GFP_KERNEL);
+        if (!mutex_ptr)
+                goto out;
+        imx6_sema4->mutex_ptr[mutex_num] = mutex_ptr;
+        imx6_sema4->alloced |= 1 < mutex_num;
+        imx6_sema4->cpine_val |= idx_sema4[mutex_num];
+        writew(imx6_sema4->cpine_val, imx6_sema4->ioaddr + SEMA4_CP0INE);
+
+        mutex_ptr->valid = CORE_MUTEX_VALID;
+        mutex_ptr->gate_num = mutex_num;
+        init_waitqueue_head(&mutex_ptr->wait_q);
+
+out:
+        return mutex_ptr;
+}
+EXPORT_SYMBOL(imx_sema4_mutex_create);
+
+/*!
+ * \brief mutex destroy function.
+ *
+ * This function destroys a mutex.
+ *
+ * \param[in] mutex_ptr   Pointer to mutex structure.
+ *
+ * \return MQX_COMPONENT_DOES_NOT_EXIST (mutex component not installed.)
+ * \return MQX_INVALID_PARAMETER (Wrong input parameter.)
+ * \return COREMUTEX_OK (Success.)
+ *
+ */
+int imx_sema4_mutex_destroy(struct imx_sema4_mutex *mutex_ptr)
+{
+        u32 mutex_num;
+
+        if ((mutex_ptr == NULL) || (mutex_ptr->valid != CORE_MUTEX_VALID))
+                return -EINVAL;
+
+        mutex_num = mutex_ptr->gate_num;
+        if ((imx6_sema4->cpine_val & idx_sema4[mutex_num]) == 0) {
+                pr_err("Error: trying to destory a un-allocated sema4.\n");
+                pr_err("mutex_num %d cpine_val 0x%08x.\n",
+                                mutex_num, imx6_sema4->cpine_val);
+        }
+        imx6_sema4->mutex_ptr[mutex_num] = NULL;
+        imx6_sema4->alloced &= ~(1 << mutex_num);
+        imx6_sema4->cpine_val &= ~(idx_sema4[mutex_num]);
+        writew(imx6_sema4->cpine_val, imx6_sema4->ioaddr + SEMA4_CP0INE);
+
+        kfree(mutex_ptr);
+
+        return 0;
+}
+EXPORT_SYMBOL(imx_sema4_mutex_destroy);
+
+/*!
+ * \brief Lock the mutex, shouldn't be interruted by INT.
+ *
+ * This function attempts to lock a mutex. If the mutex is already locked
+ * by another task the function return -EBUSY, and tell invoker wait until
+ * it is possible to lock the mutex.
+ *
+ * \param[in] mutex_ptr   Pointer to mutex structure.
+ *
+ * \return MQX_INVALID_POINTER (Wrong pointer to the mutex structure provided.)
+ * \return COREMUTEX_OK (mutex successfully locked.)
+ *
+ * \see imx_sema4_mutex_unlock
+ */
+int _imx_sema4_mutex_lock(struct imx_sema4_mutex *mutex_ptr)
+{
+        int ret = 0, i = mutex_ptr->gate_num;
+
+        if ((mutex_ptr == NULL) || (mutex_ptr->valid != CORE_MUTEX_VALID))
+                return -EINVAL;
+
+        mutex_ptr->gate_val = readb(imx6_sema4->ioaddr + i);
+        mutex_ptr->gate_val &= SEMA4_GATE_MASK;
+        /* Check to see if this core already own it */
+        if (mutex_ptr->gate_val == SEMA4_A9_LOCK) {
+                /* return -EBUSY, invoker should be in sleep, and re-lock ag */
+                pr_err("%s -> %s %d already locked, wait! num %d val %d.\n",
+                                __FILE__, __func__, __LINE__,
+                                i, mutex_ptr->gate_val);
+                ret = -EBUSY;
+                goto out;
+        } else {
+                /* try to lock the mutex */
+                mutex_ptr->gate_val = readb(imx6_sema4->ioaddr + i);
+                mutex_ptr->gate_val &= (~SEMA4_GATE_MASK);
+                mutex_ptr->gate_val |= SEMA4_A9_LOCK;
+                writeb(mutex_ptr->gate_val, imx6_sema4->ioaddr + i);
+                mutex_ptr->gate_val = readb(imx6_sema4->ioaddr + i);
+                mutex_ptr->gate_val &= SEMA4_GATE_MASK;
+                /* double check the mutex is locked, otherwise, return -EBUSY */
+                if (mutex_ptr->gate_val != SEMA4_A9_LOCK) {
+                        pr_debug("wait-locked num %d val %d.\n",
+                                        i, mutex_ptr->gate_val);
+                        ret = -EBUSY;
+                }
+        }
+out:
+        return ret;
+}
+
+/* !
+ * \brief Try to lock the core mutex.
+ *
+ * This function attempts to lock a mutex. If the mutex is successfully locked
+ * for the calling task, SEMA4_A9_LOCK is returned. If the mutex is already
+ * locked by another task, the function does not block but rather returns
+ * negative immediately.
+ *
+ * \param[in] mutex_ptr  Pointer to core_mutex structure.
+ *
+ * \return SEMA4_A9_LOCK (mutex successfully locked.)
+ * \return negative (mutex not locked.)
+ *
+ */
+int imx_sema4_mutex_trylock(struct imx_sema4_mutex *mutex_ptr)
+{
+        int ret = 0;
+
+        ret = _imx_sema4_mutex_lock(mutex_ptr);
+        if (ret == 0)
+                return SEMA4_A9_LOCK;
+        else
+                return ret;
+}
+EXPORT_SYMBOL(imx_sema4_mutex_trylock);
+
+/*!
+ * \brief Invoke _imx_sema4_mutex_lock to lock the mutex.
+ *
+ * This function attempts to lock a mutex. If the mutex is already locked
+ * by another task the function, sleep itself and schedule out.
+ * Wait until it is possible to lock the mutex.
+ *
+ * Invoker should add its own wait queue into the wait queue header of the
+ * required semaphore, set TASK_INTERRUPTIBLE and sleep on itself by
+ * schedule() when the lock is failed. Re-try to lock the semaphore when
+ * it is woke up by the sema4 isr.
+ *
+ * \param[in] mutex_ptr  Pointer to mutex structure.
+ *
+ * \return SEMA4_A9_LOCK (mutex successfully locked.)
+ *
+ * \see imx_sema4_mutex_unlock
+ */
+int imx_sema4_mutex_lock(struct imx_sema4_mutex *mutex_ptr)
+{
+        int ret = 0;
+        unsigned long flags;
+        unsigned long timeout_j; /* jiffies */
+
+        spin_lock_irqsave(&imx6_sema4->lock, flags);
+        ret = _imx_sema4_mutex_lock(mutex_ptr);
+        spin_unlock_irqrestore(&imx6_sema4->lock, flags);
+        while (-EBUSY == ret) {
+                if (MCC_SHMEM_SEMAPHORE_NUMBER == mutex_ptr->gate_num) {
+                        timeout_j = msecs_to_jiffies(1000);
+                        wait_event_timeout(mutex_ptr->wait_q,
+                                        mutex_ptr->gate_val == 0, timeout_j);
+                        pr_debug("wake up val %d.\n", mutex_ptr->gate_val);
+                }
+                spin_lock_irqsave(&imx6_sema4->lock, flags);
+                ret = _imx_sema4_mutex_lock(mutex_ptr);
+                spin_unlock_irqrestore(&imx6_sema4->lock, flags);
+                if (ret == 0)
+                        break;
+        }
+
+        return ret;
+}
+EXPORT_SYMBOL(imx_sema4_mutex_lock);
+
+/*!
+ * \brief Unlock the mutex.
+ *
+ * This function unlocks the specified mutex.
+ *
+ * \param[in] mutex_ptr   Pointer to mutex structure.
+ *
+ * \return -EINVAL (Wrong pointer to the mutex structure provided.)
+ * \return -EINVAL (This mutex has not been locked by this core.)
+ * \return 0 (mutex successfully unlocked.)
+ *
+ * \see imx_sema4_mutex_lock
+ */
+int imx_sema4_mutex_unlock(struct imx_sema4_mutex *mutex_ptr)
+{
+        int ret = 0, i = mutex_ptr->gate_num;
+
+        if ((mutex_ptr == NULL) || (mutex_ptr->valid != CORE_MUTEX_VALID))
+                return -EINVAL;
+
+        mutex_ptr->gate_val = readb(imx6_sema4->ioaddr + i);
+        mutex_ptr->gate_val &= SEMA4_GATE_MASK;
+        /* make sure it is locked by this core */
+        if (mutex_ptr->gate_val != SEMA4_A9_LOCK) {
+                pr_err("%d Trying to unlock an unlock mutex.\n", __LINE__);
+                ret = -EINVAL;
+                goto out;
+        }
+        /* unlock it */
+        mutex_ptr->gate_val = readb(imx6_sema4->ioaddr + i);
+        mutex_ptr->gate_val &= (~SEMA4_GATE_MASK);
+        writeb(mutex_ptr->gate_val | SEMA4_UNLOCK, imx6_sema4->ioaddr + i);
+        mutex_ptr->gate_val = readb(imx6_sema4->ioaddr + i);
+        mutex_ptr->gate_val &= SEMA4_GATE_MASK;
+        /* make sure it is locked by this core */
+        if (mutex_ptr->gate_val != SEMA4_UNLOCK)
+                pr_err("%d ERROR, failed to unlock the mutex.\n", __LINE__);
+
+out:
+        return ret;
+}
+EXPORT_SYMBOL(imx_sema4_mutex_unlock);
+
+/*
+ * isr used by SEMA4, wake up the sleep tasks if there are the tasks waiting
+ * for locking semaphore.
+ * FIXME the bits order of the gatn, cpnie, cpnntf are not exact identified yet!
+ */
+static irqreturn_t imx_sema4_isr(int irq, void *dev_id)
+{
+        int i;
+        struct imx_sema4_mutex *mutex_ptr;
+        u32 mask;
+        struct imx_sema4_mutex_device *imx6_sema4 = dev_id;
+
+        imx6_sema4->cpntf_val = readw(imx6_sema4->ioaddr + SEMA4_CP0NTF);
+        for (i = 0; i < SEMA4_NUM_GATES; i++) {
+                mask = idx_sema4[i];
+                if ((imx6_sema4->cpntf_val) & mask) {
+                        mutex_ptr = imx6_sema4->mutex_ptr[i];
+                        /*
+                         * An interrupt is pending on this mutex, the only way
+                         * to clear it is to lock it (either by this core or
+                         * another).
+                         */
+                        mutex_ptr->gate_val = readb(imx6_sema4->ioaddr + i);
+                        mutex_ptr->gate_val &= (~SEMA4_GATE_MASK);
+                        mutex_ptr->gate_val |= SEMA4_A9_LOCK;
+                        writeb(mutex_ptr->gate_val, imx6_sema4->ioaddr + i);
+                        mutex_ptr->gate_val = readb(imx6_sema4->ioaddr + i);
+                        mutex_ptr->gate_val &= SEMA4_GATE_MASK;
+                        if (mutex_ptr->gate_val == SEMA4_A9_LOCK) {
+                                /*
+                                 * wake up the wait queue, whatever there
+                                 * are wait task or not.
+                                 * NOTE: check gate is locted or not in
+                                 * sema4_lock func by wait task.
+                                 */
+                                mutex_ptr->gate_val =
+                                        readb(imx6_sema4->ioaddr + i);
+                                mutex_ptr->gate_val &= (~SEMA4_GATE_MASK);
+                                mutex_ptr->gate_val |= SEMA4_UNLOCK;
+
+                                writeb(mutex_ptr->gate_val,
+                                                imx6_sema4->ioaddr + i);
+                                wake_up(&mutex_ptr->wait_q);
+                        } else {
+                                pr_err("can't lock gate%d re-do it! %s->%s\n",
+                                                i, __FILE__, __func__);
+                        }
+                }
+        }
+
+        return IRQ_HANDLED;
+}
+
+static const struct of_device_id imx_sema4_dt_ids[] = {
+        { .compatible = "fsl,imx6sx-sema4", },
+        { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, imx_sema4_dt_ids);
+
+static int imx_sema4_probe(struct platform_device *pdev)
+{
+        struct resource *res;
+        int ret;
+
+        imx6_sema4 = devm_kzalloc(&pdev->dev, sizeof(*imx6_sema4), GFP_KERNEL);
+        if (!imx6_sema4)
+                return -ENOMEM;
+
+        imx6_sema4->dev = &pdev->dev;
+        imx6_sema4->cpine_val = 0;
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        if (IS_ERR(res)) {
+                dev_err(&pdev->dev, "unable to get imx sema4 resource 0\n");
+                ret = -ENODEV;
+                goto err;
+        }
+
+        imx6_sema4->ioaddr = devm_ioremap_resource(&pdev->dev, res);
+        if (IS_ERR(imx6_sema4->ioaddr)) {
+                ret = PTR_ERR(imx6_sema4->ioaddr);
+                goto err;
+        }
+
+        imx6_sema4->irq = platform_get_irq(pdev, 0);
+        if (!imx6_sema4->irq) {
+                dev_err(&pdev->dev, "failed to get irq\n");
+                ret = -ENODEV;
+                goto err;
+        }
+
+        ret = devm_request_irq(&pdev->dev, imx6_sema4->irq, imx_sema4_isr,
+                                IRQF_SHARED, "imx6sx-sema4", imx6_sema4);
+        if (ret) {
+                dev_err(&pdev->dev, "failed to request imx sema4 irq\n");
+                ret = -ENODEV;
+                goto err;
+        }
+
+        platform_set_drvdata(pdev, imx6_sema4);
+
+err:
+        return ret;
+}
+
+static int imx_sema4_remove(struct platform_device *pdev)
+{
+        return 0;
+}
+
+static struct platform_driver imx_sema4_driver = {
+        .driver = {
+                   .owner = THIS_MODULE,
+                   .name = "imx-sema4",
+                   .of_match_table = imx_sema4_dt_ids,
+                   },
+        .probe = imx_sema4_probe,
+        .remove = imx_sema4_remove,
+};
+
+static int __init imx_sema4_init(void)
+{
+        int ret;
+
+        ret = platform_driver_register(&imx_sema4_driver);
+        if (ret)
+                pr_err("Unable to initialize sema4 driver\n");
+        else
+                pr_info("imx sema4 driver is registered.\n");
+
+        return ret;
+}
+
+static void __exit imx_sema4_exit(void)
+{
+        pr_info("imx sema4 driver is unregistered.\n");
+        platform_driver_unregister(&imx_sema4_driver);
+}
+
+module_exit(imx_sema4_exit);
+module_init(imx_sema4_init);
+
+MODULE_AUTHOR("Freescale Semiconductor, Inc.");
+MODULE_DESCRIPTION("IMX SEMA4 driver");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/imx_sema4.h b/include/linux/imx_sema4.h
new file mode 100644
index 000000000000..51a25e1b51bc
--- /dev/null
+++ b/include/linux/imx_sema4.h
@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) 2014 Freescale Semiconductor, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __LINUX_IMX_SEMA4_H__
+#define __LINUX_IMX_SEMA4_H__
+
+/* semaphore number */
+#define MCC_SHMEM_SEMAPHORE_NUMBER      (1)
+#define MCC_PRINTF_SEMAPHORE_NUMBER     (2)
+#define MCC_I2C_SEMAPHORE_NUMBER        (3)
+#define MCC_RESERVED1_SEMAPHORE_NUMBER  (4)
+#define MCC_RESERVED2_SEMAPHORE_NUMBER  (5)
+
+#define SEMA4_NUM_DEVICES       1
+#define SEMA4_NUM_GATES         16
+
+#define SEMA4_UNLOCK    0x00
+#define SEMA4_A9_LOCK   0x01
+#define SEMA4_GATE_MASK 0x03
+
+#define CORE_MUTEX_VALID        (('c'<<24)|('m'<<24)|('t'<<24)|'x')
+
+/*
+ * The enumerates
+ */
+enum {
+        /* sema4 registers offset */
+        SEMA4_CP0INE    = 0x40,
+        SEMA4_CP1INE    = 0x48,
+        SEMA4_CP0NTF    = 0x80,
+        SEMA4_CP1NTF    = 0x88,
+};
+
+static const unsigned int idx_sema4[16] = {
+        1 << 7, 1 << 6, 1 << 5, 1 << 4,
+        1 << 3, 1 << 2, 1 << 1, 1 << 0,
+        1 << 15, 1 << 14, 1 << 13, 1 << 12,
+        1 << 11, 1 << 10, 1 << 9, 1 << 8,
+};
+
+struct imx_sema4_mutex {
+        u32                     valid;
+        u32                     gate_num;
+        unsigned char           gate_val;
+        wait_queue_head_t       wait_q;
+};
+
+struct imx_sema4_mutex_device {
+        struct device           *dev;
+        u16                     cpntf_val;
+        u16                     cpine_val;
+        void __iomem            *ioaddr;        /* Mapped address */
+        spinlock_t              lock;           /* Mutex */
+        int                     irq;
+
+        u16                     alloced;
+        struct imx_sema4_mutex  *mutex_ptr[16];
+};
+
+struct imx_sema4_mutex *
+        imx_sema4_mutex_create(u32 dev_num, u32 mutex_num);
+int imx_sema4_mutex_destroy(struct imx_sema4_mutex *mutex_ptr);
+int imx_sema4_mutex_trylock(struct imx_sema4_mutex *mutex_ptr);
+int imx_sema4_mutex_lock(struct imx_sema4_mutex *mutex_ptr);
+int imx_sema4_mutex_unlock(struct imx_sema4_mutex *mutex_ptr);
+#endif /* __LINUX_IMX_SEMA4_H__ */