These changes are the raw update to linux-4.4.6-rt14. Kernel sources

[kvmfornfv.git] / kernel / drivers / hwspinlock / sirf_hwspinlock.c

diff --git a/kernel/drivers/hwspinlock/sirf_hwspinlock.c b/kernel/drivers/hwspinlock/sirf_hwspinlock.c
new file mode 100644 (file)
index 0000000..1601854
--- /dev/null
+++ b/kernel/drivers/hwspinlock/sirf_hwspinlock.c
@@ -0,0 +1,136 @@
+/*
+ * SIRF hardware spinlock driver
+ *
+ * Copyright (c) 2015 Cambridge Silicon Radio Limited, a CSR plc group company.
+ *
+ * Licensed under GPLv2.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/pm_runtime.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/hwspinlock.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+
+#include "hwspinlock_internal.h"
+
+struct sirf_hwspinlock {
+       void __iomem *io_base;
+       struct hwspinlock_device bank;
+};
+
+/* Number of Hardware Spinlocks*/
+#define        HW_SPINLOCK_NUMBER      30
+
+/* Hardware spinlock register offsets */
+#define HW_SPINLOCK_BASE       0x404
+#define HW_SPINLOCK_OFFSET(x)  (HW_SPINLOCK_BASE + 0x4 * (x))
+
+static int sirf_hwspinlock_trylock(struct hwspinlock *lock)
+{
+       void __iomem *lock_addr = lock->priv;
+
+       /* attempt to acquire the lock by reading value == 1 from it */
+       return !!readl(lock_addr);
+}
+
+static void sirf_hwspinlock_unlock(struct hwspinlock *lock)
+{
+       void __iomem *lock_addr = lock->priv;
+
+       /* release the lock by writing 0 to it */
+       writel(0, lock_addr);
+}
+
+static const struct hwspinlock_ops sirf_hwspinlock_ops = {
+       .trylock = sirf_hwspinlock_trylock,
+       .unlock = sirf_hwspinlock_unlock,
+};
+
+static int sirf_hwspinlock_probe(struct platform_device *pdev)
+{
+       struct sirf_hwspinlock *hwspin;
+       struct hwspinlock *hwlock;
+       int idx, ret;
+
+       if (!pdev->dev.of_node)
+               return -ENODEV;
+
+       hwspin = devm_kzalloc(&pdev->dev, sizeof(*hwspin) +
+                       sizeof(*hwlock) * HW_SPINLOCK_NUMBER, GFP_KERNEL);
+       if (!hwspin)
+               return -ENOMEM;
+
+       /* retrieve io base */
+       hwspin->io_base = of_iomap(pdev->dev.of_node, 0);
+       if (!hwspin->io_base)
+               return -ENOMEM;
+
+       for (idx = 0; idx < HW_SPINLOCK_NUMBER; idx++) {
+               hwlock = &hwspin->bank.lock[idx];
+               hwlock->priv = hwspin->io_base + HW_SPINLOCK_OFFSET(idx);
+       }
+
+       platform_set_drvdata(pdev, hwspin);
+
+       pm_runtime_enable(&pdev->dev);
+
+       ret = hwspin_lock_register(&hwspin->bank, &pdev->dev,
+                                  &sirf_hwspinlock_ops, 0,
+                                  HW_SPINLOCK_NUMBER);
+       if (ret)
+               goto reg_failed;
+
+       return 0;
+
+reg_failed:
+       pm_runtime_disable(&pdev->dev);
+       iounmap(hwspin->io_base);
+
+       return ret;
+}
+
+static int sirf_hwspinlock_remove(struct platform_device *pdev)
+{
+       struct sirf_hwspinlock *hwspin = platform_get_drvdata(pdev);
+       int ret;
+
+       ret = hwspin_lock_unregister(&hwspin->bank);
+       if (ret) {
+               dev_err(&pdev->dev, "%s failed: %d\n", __func__, ret);
+               return ret;
+       }
+
+       pm_runtime_disable(&pdev->dev);
+
+       iounmap(hwspin->io_base);
+
+       return 0;
+}
+
+static const struct of_device_id sirf_hwpinlock_ids[] = {
+       { .compatible = "sirf,hwspinlock", },
+       {},
+};
+MODULE_DEVICE_TABLE(of, sirf_hwpinlock_ids);
+
+static struct platform_driver sirf_hwspinlock_driver = {
+       .probe = sirf_hwspinlock_probe,
+       .remove = sirf_hwspinlock_remove,
+       .driver = {
+               .name = "atlas7_hwspinlock",
+               .of_match_table = of_match_ptr(sirf_hwpinlock_ids),
+       },
+};
+
+module_platform_driver(sirf_hwspinlock_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("SIRF Hardware spinlock driver");
+MODULE_AUTHOR("Wei Chen <wei.chen@csr.com>");