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path: root/kernel/drivers/hwspinlock/sirf_hwspinlock.c
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Diffstat (limited to 'kernel/drivers/hwspinlock/sirf_hwspinlock.c')
-rw-r--r--kernel/drivers/hwspinlock/sirf_hwspinlock.c136
1 files changed, 136 insertions, 0 deletions
diff --git a/kernel/drivers/hwspinlock/sirf_hwspinlock.c b/kernel/drivers/hwspinlock/sirf_hwspinlock.c
new file mode 100644
index 000000000..16018544d
--- /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>");