diff options
Diffstat (limited to 'drivers/char/imx_amp/imx_sema4.c')
| -rw-r--r-- | drivers/char/imx_amp/imx_sema4.c | 413 |
1 files changed, 413 insertions, 0 deletions
diff --git a/drivers/char/imx_amp/imx_sema4.c b/drivers/char/imx_amp/imx_sema4.c new file mode 100644 index 000000000000..412202f11cbb --- /dev/null +++ b/drivers/char/imx_amp/imx_sema4.c @@ -0,0 +1,413 @@ +/* + * 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 destroy 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 = 0; + + if ((mutex_ptr == NULL) || (mutex_ptr->valid != CORE_MUTEX_VALID)) + return -EINVAL; + + i = mutex_ptr->gate_num; + 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; + + spin_lock_irqsave(&imx6_sema4->lock, flags); + ret = _imx_sema4_mutex_lock(mutex_ptr); + spin_unlock_irqrestore(&imx6_sema4->lock, flags); + while (-EBUSY == ret) { + 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 = 0; + + if ((mutex_ptr == NULL) || (mutex_ptr->valid != CORE_MUTEX_VALID)) + return -EINVAL; + + i = mutex_ptr->gate_num; + 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_A9_LOCK) + 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; + unsigned int 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_debug("can't lock gate%d %s retry!\n", i, + mutex_ptr->gate_val ? + "locked by m4" : ""); + } + } + } + + 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; + spin_lock_init(&imx6_sema4->lock); + + 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"); |