1 files changed, 306 insertions, 0 deletions
diff --git a/drivers/char/vf610_sema4.c b/drivers/char/vf610_sema4.c
new file mode 100644
index 000000000000..dff78bd3e22b
--- /dev/null
+++ b/drivers/char/vf610_sema4.c
@@ -0,0 +1,306 @@
+/*
+ * Copyright (C) 2014 Freescale Semiconductor, Inc.
+ * Copyright (C) 2016 Toradex AG.
+ *
+ * Taken from the 4.1.15 kernel release for i.MX7 by Freescale.
+ *
+ * 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/vf610_sema4.h>
+
+static struct vf610_sema4_mutex_device *vf610_sema4;
+
+struct vf610_sema4_mutex *
+vf610_sema4_mutex_create(u32 dev_num, u32 mutex_num)
+{
+	struct vf610_sema4_mutex *mutex_ptr = NULL;
+
+	if (!vf610_sema4)
+		return ERR_PTR(-ENODEV);
+
+	if (mutex_num >= SEMA4_NUM_GATES || dev_num >= SEMA4_NUM_DEVICES)
+		return ERR_PTR(-EINVAL);
+
+	if (vf610_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, vf610_sema4->cpine_val);
+	}
+
+	mutex_ptr = kzalloc(sizeof(*mutex_ptr), GFP_KERNEL);
+	if (!mutex_ptr)
+		return ERR_PTR(-ENOMEM);
+
+	vf610_sema4->mutex_ptr[mutex_num] = mutex_ptr;
+	vf610_sema4->alloced |= 1 < mutex_num;
+	vf610_sema4->cpine_val |= idx_sema4[mutex_num];
+	writew(vf610_sema4->cpine_val, vf610_sema4->ioaddr + SEMA4_CP0INE);
+
+	mutex_ptr->valid = CORE_MUTEX_VALID;
+	mutex_ptr->gate_num = mutex_num;
+	init_waitqueue_head(&mutex_ptr->wait_q);
+
+	return mutex_ptr;
+}
+EXPORT_SYMBOL(vf610_sema4_mutex_create);
+
+int vf610_sema4_mutex_destroy(struct vf610_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 ((vf610_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, vf610_sema4->cpine_val);
+	}
+	vf610_sema4->mutex_ptr[mutex_num] = NULL;
+	vf610_sema4->alloced &= ~(1 << mutex_num);
+	vf610_sema4->cpine_val &= ~(idx_sema4[mutex_num]);
+	writew(vf610_sema4->cpine_val, vf610_sema4->ioaddr + SEMA4_CP0INE);
+
+	kfree(mutex_ptr);
+
+	return 0;
+}
+EXPORT_SYMBOL(vf610_sema4_mutex_destroy);
+
+int _vf610_sema4_mutex_lock(struct vf610_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(vf610_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_A5_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(vf610_sema4->ioaddr + i);
+		mutex_ptr->gate_val &= (~SEMA4_GATE_MASK);
+		mutex_ptr->gate_val |= SEMA4_A5_LOCK;
+		writeb(mutex_ptr->gate_val, vf610_sema4->ioaddr + i);
+		mutex_ptr->gate_val = readb(vf610_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_A5_LOCK) {
+			pr_debug("wait-locked num %d val %d.\n",
+					i, mutex_ptr->gate_val);
+			ret = -EBUSY;
+		}
+	}
+out:
+	return ret;
+}
+
+int vf610_sema4_mutex_trylock(struct vf610_sema4_mutex *mutex_ptr)
+{
+	int ret = 0;
+
+	ret = _vf610_sema4_mutex_lock(mutex_ptr);
+	if (ret == 0)
+		return SEMA4_A5_LOCK;
+	else
+		return ret;
+}
+EXPORT_SYMBOL(vf610_sema4_mutex_trylock);
+
+int vf610_sema4_mutex_lock(struct vf610_sema4_mutex *mutex_ptr)
+{
+	int ret = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&vf610_sema4->lock, flags);
+	ret = _vf610_sema4_mutex_lock(mutex_ptr);
+	spin_unlock_irqrestore(&vf610_sema4->lock, flags);
+	while (-EBUSY == ret) {
+		spin_lock_irqsave(&vf610_sema4->lock, flags);
+		ret = _vf610_sema4_mutex_lock(mutex_ptr);
+		spin_unlock_irqrestore(&vf610_sema4->lock, flags);
+		if (ret == 0)
+			break;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(vf610_sema4_mutex_lock);
+
+int vf610_sema4_mutex_unlock(struct vf610_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(vf610_sema4->ioaddr + i);
+	mutex_ptr->gate_val &= SEMA4_GATE_MASK;
+	/* make sure it is locked by this core */
+	if (mutex_ptr->gate_val != SEMA4_A5_LOCK) {
+		pr_err("%d Trying to unlock an unlock mutex.\n", __LINE__);
+		ret = -EINVAL;
+		goto out;
+	}
+	/* unlock it */
+	mutex_ptr->gate_val = readb(vf610_sema4->ioaddr + i);
+	mutex_ptr->gate_val &= (~SEMA4_GATE_MASK);
+	writeb(mutex_ptr->gate_val | SEMA4_UNLOCK, vf610_sema4->ioaddr + i);
+	mutex_ptr->gate_val = readb(vf610_sema4->ioaddr + i);
+	mutex_ptr->gate_val &= SEMA4_GATE_MASK;
+	/* make sure it is locked by this core */
+	if (mutex_ptr->gate_val == SEMA4_A5_LOCK)
+		pr_err("%d ERROR, failed to unlock the mutex.\n", __LINE__);
+
+out:
+	return ret;
+}
+EXPORT_SYMBOL(vf610_sema4_mutex_unlock);
+
+static irqreturn_t vf610_sema4_isr(int irq, void *dev_id)
+{
+	int i;
+	struct vf610_sema4_mutex *mutex_ptr;
+	unsigned int mask;
+	struct vf610_sema4_mutex_device *vf610_sema4 = dev_id;
+
+	vf610_sema4->cpntf_val = readw(vf610_sema4->ioaddr + SEMA4_CP0NTF);
+	for (i = 0; i < SEMA4_NUM_GATES; i++) {
+		mask = idx_sema4[i];
+		if ((vf610_sema4->cpntf_val) & mask) {
+			mutex_ptr = vf610_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(vf610_sema4->ioaddr + i);
+			mutex_ptr->gate_val &= (~SEMA4_GATE_MASK);
+			mutex_ptr->gate_val |= SEMA4_A5_LOCK;
+			writeb(mutex_ptr->gate_val, vf610_sema4->ioaddr + i);
+			mutex_ptr->gate_val = readb(vf610_sema4->ioaddr + i);
+			mutex_ptr->gate_val &= SEMA4_GATE_MASK;
+			if (mutex_ptr->gate_val == SEMA4_A5_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(vf610_sema4->ioaddr + i);
+				mutex_ptr->gate_val &= (~SEMA4_GATE_MASK);
+				mutex_ptr->gate_val |= SEMA4_UNLOCK;
+
+				writeb(mutex_ptr->gate_val,
+						vf610_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 vf610_sema4_dt_ids[] = {
+	{ .compatible = "fsl,vf610-sema4", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, vf610_sema4_dt_ids);
+
+static int vf610_sema4_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	int ret;
+
+	vf610_sema4 = devm_kzalloc(&pdev->dev, sizeof(*vf610_sema4), GFP_KERNEL);
+	if (!vf610_sema4)
+		return -ENOMEM;
+
+	vf610_sema4->dev = &pdev->dev;
+	vf610_sema4->cpine_val = 0;
+	spin_lock_init(&vf610_sema4->lock);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (IS_ERR(res)) {
+		dev_err(&pdev->dev, "unable to get vf610 sema4 resource 0\n");
+		ret = -ENODEV;
+		goto err;
+	}
+
+	vf610_sema4->ioaddr = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(vf610_sema4->ioaddr)) {
+		ret = PTR_ERR(vf610_sema4->ioaddr);
+		goto err;
+	}
+
+	vf610_sema4->irq = platform_get_irq(pdev, 0);
+	if (!vf610_sema4->irq) {
+		dev_err(&pdev->dev, "failed to get irq\n");
+		ret = -ENODEV;
+		goto err;
+	}
+
+	ret = devm_request_irq(&pdev->dev, vf610_sema4->irq, vf610_sema4_isr,
+				IRQF_SHARED, "vf610-sema4", vf610_sema4);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to request vf610 sema4 irq\n");
+		ret = -ENODEV;
+		goto err;
+	}
+
+	platform_set_drvdata(pdev, vf610_sema4);
+
+err:
+	return ret;
+}
+
+static int vf610_sema4_remove(struct platform_device *pdev)
+{
+	return 0;
+}
+
+static struct platform_driver vf610_sema4_driver = {
+	.driver = {
+		   .owner = THIS_MODULE,
+		   .name = "vf610-sema4",
+		   .of_match_table = vf610_sema4_dt_ids,
+		   },
+	.probe = vf610_sema4_probe,
+	.remove = vf610_sema4_remove,
+};
+
+module_platform_driver(vf610_sema4_driver);
+
+MODULE_DESCRIPTION("VF610 SEMA4 driver");
+MODULE_LICENSE("GPL");