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Date: Fri, 6 Mar 2015 16:30:13 +0800
From: Barry Song <21cnbao@...il.com>
To: ohad@...ery.com, linux-kernel@...r.kernel.org
Cc: workgroup.linux@....com, Wei Chen <wei.chen@....com>,
Barry Song <Baohua.Song@....com>
Subject: [PATCH] drivers: hwspinlock: add CSR atlas7 implementation
From: Wei Chen <wei.chen@....com>
Add hwspinlock support for the CSR atlas7 SoC.
The Hardware Spinlock device on atlas7 provides hardware assistance
for synchronization between the multiple processors in the system
(dual Cortex-A7, CAN bus Cortex-M3 and audio DSP).
Signed-off-by: Wei Chen <wei.chen@....com>
Signed-off-by: Barry Song <Baohua.Song@....com>
---
.../bindings/hwspinlock/sirf,hwspinlock.txt | 18 +++
drivers/hwspinlock/Kconfig | 12 ++
drivers/hwspinlock/Makefile | 1 +
drivers/hwspinlock/sirf_hwspinlock.c | 151 +++++++++++++++++++++
4 files changed, 182 insertions(+)
create mode 100644 Documentation/devicetree/bindings/hwspinlock/sirf,hwspinlock.txt
create mode 100644 drivers/hwspinlock/sirf_hwspinlock.c
diff --git a/Documentation/devicetree/bindings/hwspinlock/sirf,hwspinlock.txt b/Documentation/devicetree/bindings/hwspinlock/sirf,hwspinlock.txt
new file mode 100644
index 0000000..b22c492
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwspinlock/sirf,hwspinlock.txt
@@ -0,0 +1,18 @@
+SIRF Hardware spinlock device Binding
+-----------------------------------------------
+
+Required properties :
+- compatible : shall contain only one of the following:
+ "sirf,hwspinlock"
+
+- reg : the register address of hwspinlock
+
+- num-spinlocks : how many spinlocks this device provides
+
+Example:
+ hwspinlock {
+ compatible = "sirf,hwspinlock";
+ reg = <0x13240000 0x00010000>;
+
+ num-spinlocks = <30>;
+ };
diff --git a/drivers/hwspinlock/Kconfig b/drivers/hwspinlock/Kconfig
index 3612cb5..fc400e4 100644
--- a/drivers/hwspinlock/Kconfig
+++ b/drivers/hwspinlock/Kconfig
@@ -29,4 +29,16 @@ config HSEM_U8500
If unsure, say N.
+config HWSPINLOCK_SIRF
+ tristate "SIRF Hardware Spinlock device"
+ depends on ARCH_SIRF
+ select HWSPINLOCK
+ help
+ Say y here to support the SIRF Hardware Spinlock device, which
+ provides a synchronisation mechanism for the various processor
+ on the SoC.
+
+ It's safe to say n here if you're not interested in SIRF hardware
+ spinlock or just want a bare minimum kernel.
+
endmenu
diff --git a/drivers/hwspinlock/Makefile b/drivers/hwspinlock/Makefile
index 93eb64b..472b82d 100644
--- a/drivers/hwspinlock/Makefile
+++ b/drivers/hwspinlock/Makefile
@@ -5,3 +5,4 @@
obj-$(CONFIG_HWSPINLOCK) += hwspinlock_core.o
obj-$(CONFIG_HWSPINLOCK_OMAP) += omap_hwspinlock.o
obj-$(CONFIG_HSEM_U8500) += u8500_hsem.o
+obj-$(CONFIG_HWSPINLOCK_SIRF) += sirf_hwspinlock.o
diff --git a/drivers/hwspinlock/sirf_hwspinlock.c b/drivers/hwspinlock/sirf_hwspinlock.c
new file mode 100644
index 0000000..b7ef2b2
--- /dev/null
+++ b/drivers/hwspinlock/sirf_hwspinlock.c
@@ -0,0 +1,151 @@
+/*
+ * SIRF hardware spinlock driver
+ *
+ * Copyright (c) 2014 Cambridge Silicon Radio Limited, a CSR plc group company.
+ *
+ * Licensed under GPLv2 or later.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/bitops.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;
+};
+
+/* Hardware spinlock register offsets */
+#define HW_SPINLOCK_RD_DEBUG 0x400
+#define HW_SPINLOCK_BASE 0x404
+#define HW_SPINLOCK_OFFSET(x) (HW_SPINLOCK_BASE + 0x4 * (x))
+
+/* Possible values of HW_SPINLOCK_REG */
+#define HW_SPINLOCK_LOCKED 0
+#define HW_SPINLOCK_FREE 1
+
+static int sirf_hwspinlock_trylock(struct hwspinlock *lock)
+{
+ void __iomem *lock_addr = lock->priv;
+
+ /* attempt to acquire the lock by reading its value */
+ return (HW_SPINLOCK_FREE == 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(HW_SPINLOCK_LOCKED, lock_addr);
+}
+
+static void sirf_hwspinlock_relax(struct hwspinlock *lock)
+{
+ ndelay(50);
+}
+
+static const struct hwspinlock_ops sirf_hwspinlock_ops = {
+ .trylock = sirf_hwspinlock_trylock,
+ .unlock = sirf_hwspinlock_unlock,
+ .relax = sirf_hwspinlock_relax,
+};
+
+static int sirf_hwspinlock_probe(struct platform_device *pdev)
+{
+ struct sirf_hwspinlock *hwspin;
+ struct hwspinlock *hwlock;
+ u32 num_of_locks;
+ int idx, ret;
+
+ ret = of_property_read_u32(pdev->dev.of_node,
+ "num-spinlocks", &num_of_locks);
+ if (ret) {
+ dev_err(&pdev->dev,
+ "Unable to find hwspinlock number. ret=%d\n", ret);
+ return -ENODEV;
+ }
+
+ hwspin = devm_kzalloc(&pdev->dev, sizeof(*hwspin) +
+ sizeof(*hwlock) * num_of_locks, GFP_KERNEL);
+ if (!hwspin)
+ return -ENOMEM;
+
+ /* retrieve io base */
+ hwspin->io_base = of_iomap(pdev->dev.of_node, 0);
+ if (!hwspin->io_base)
+ ret = -ENOMEM;
+
+ for (idx = 0; idx < num_of_locks; 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, num_of_locks);
+ 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@....com>");
--
2.3.0
--
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