MLK-11488-1 driver: char: sema4: add sema4 support

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

Signed-off-by: Anson Huang <b20788@freescale.com>
Signed-off-by: Richard Zhu <r65037@freescale.com>

5 files changed, 427 insertions, 0 deletions

diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index 8453a49471d7..013620af9d02 100644
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -593,5 +593,6 @@ config TILE_SROM
 
 source "drivers/char/xillybus/Kconfig"
 
+source "drivers/char/imx_amp/Kconfig"
 endmenu
 
diff --git a/drivers/char/Makefile b/drivers/char/Makefile
index 6e6c244a66a0..68755dc7b9eb 100644
--- a/drivers/char/Makefile
+++ b/drivers/char/Makefile
@@ -60,3 +60,4 @@ js-rtc-y = rtc.o
 obj-$(CONFIG_TILE_SROM)		+= tile-srom.o
 obj-$(CONFIG_XILLYBUS)		+= xillybus/
 obj-$(CONFIG_POWERNV_OP_PANEL)	+= powernv-op-panel.o
+obj-$(CONFIG_HAVE_IMX_AMP)      += imx_amp/
diff --git a/drivers/char/imx_amp/Kconfig b/drivers/char/imx_amp/Kconfig
new file mode 100644
index 000000000000..1f892f8daccb
--- /dev/null
+++ b/drivers/char/imx_amp/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_amp/Makefile b/drivers/char/imx_amp/Makefile
new file mode 100644
index 000000000000..4e7a91691b39
--- /dev/null
+++ b/drivers/char/imx_amp/Makefile
@@ -0,0 +1,5 @@
+#
+# Makefile for imx mcc
+#
+#
+obj-$(CONFIG_IMX_SEMA4)		+= imx_sema4.o
diff --git a/drivers/char/imx_amp/imx_sema4.c b/drivers/char/imx_amp/imx_sema4.c
new file mode 100644
index 000000000000..4ce652c03a3f
--- /dev/null
+++ b/drivers/char/imx_amp/imx_sema4.c
@@ -0,0 +1,411 @@
+/*
+ * 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 = 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;
+
+	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 = 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_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;
+	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_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");