hwspinlock: sprd: Add hardware spinlock driver

The Spreadtrum hardware spinlock device can provide hardware assistance
for synchronization between the multiple subsystems.

Signed-off-by: Baolin Wang <baolin.wang@spreadtrum.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

diff --git a/drivers/hwspinlock/Kconfig b/drivers/hwspinlock/Kconfig
index cc26b042d366b1a01ba1d7d06b010274ba54cfa0..6e0a5539a9eac625995d06d343d34f675d558db4 100644 (file)
--- a/drivers/hwspinlock/Kconfig
+++ b/drivers/hwspinlock/Kconfig
@@ -39,6 +39,15 @@ config HWSPINLOCK_SIRF
          It's safe to say n here if you're not interested in SIRF hardware
          spinlock or just want a bare minimum kernel.
 
+config HWSPINLOCK_SPRD
+       tristate "SPRD Hardware Spinlock device"
+       depends on ARCH_SPRD
+       depends on HWSPINLOCK
+       help
+         Say y here to support the SPRD Hardware Spinlock device.
+
+         If unsure, say N.
+
 config HSEM_U8500
        tristate "STE Hardware Semaphore functionality"
        depends on HWSPINLOCK

diff --git a/drivers/hwspinlock/Makefile b/drivers/hwspinlock/Makefile
index 6b59cb5a4f3a857cf26d4dc7eebfd014f338414f..14928aa7cc5a190a6cd16eaec77ddfee8d34fb80 100644 (file)
--- a/drivers/hwspinlock/Makefile
+++ b/drivers/hwspinlock/Makefile
@@ -6,4 +6,5 @@ obj-$(CONFIG_HWSPINLOCK)                += hwspinlock_core.o
 obj-$(CONFIG_HWSPINLOCK_OMAP)          += omap_hwspinlock.o
 obj-$(CONFIG_HWSPINLOCK_QCOM)          += qcom_hwspinlock.o
 obj-$(CONFIG_HWSPINLOCK_SIRF)          += sirf_hwspinlock.o
+obj-$(CONFIG_HWSPINLOCK_SPRD)          += sprd_hwspinlock.o
 obj-$(CONFIG_HSEM_U8500)               += u8500_hsem.o

diff --git a/drivers/hwspinlock/sprd_hwspinlock.c b/drivers/hwspinlock/sprd_hwspinlock.c
new file mode 100644 (file)
index 0000000..638e64a
--- /dev/null
+++ b/drivers/hwspinlock/sprd_hwspinlock.c
@@ -0,0 +1,183 @@
+/*
+ * Spreadtrum hardware spinlock driver
+ * Copyright (C) 2017 Spreadtrum  - http://www.spreadtrum.com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ */
+
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/hwspinlock.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/slab.h>
+
+#include "hwspinlock_internal.h"
+
+/* hwspinlock registers definition */
+#define HWSPINLOCK_RECCTRL             0x4
+#define HWSPINLOCK_MASTERID(_X_)       (0x80 + 0x4 * (_X_))
+#define HWSPINLOCK_TOKEN(_X_)          (0x800 + 0x4 * (_X_))
+
+/* unlocked value */
+#define HWSPINLOCK_NOTTAKEN            0x55aa10c5
+/* bits definition of RECCTRL reg */
+#define HWSPINLOCK_USER_BITS           0x1
+
+/* hwspinlock number */
+#define SPRD_HWLOCKS_NUM               32
+
+struct sprd_hwspinlock_dev {
+       void __iomem *base;
+       struct clk *clk;
+       struct hwspinlock_device bank;
+};
+
+/* try to lock the hardware spinlock */
+static int sprd_hwspinlock_trylock(struct hwspinlock *lock)
+{
+       struct sprd_hwspinlock_dev *sprd_hwlock =
+               dev_get_drvdata(lock->bank->dev);
+       void __iomem *addr = lock->priv;
+       int user_id, lock_id;
+
+       if (!readl(addr))
+               return 1;
+
+       lock_id = hwlock_to_id(lock);
+       /* get the hardware spinlock master/user id */
+       user_id = readl(sprd_hwlock->base + HWSPINLOCK_MASTERID(lock_id));
+       dev_warn(sprd_hwlock->bank.dev,
+                "hwspinlock [%d] lock failed and master/user id = %d!\n",
+                lock_id, user_id);
+       return 0;
+}
+
+/* unlock the hardware spinlock */
+static void sprd_hwspinlock_unlock(struct hwspinlock *lock)
+{
+       void __iomem *lock_addr = lock->priv;
+
+       writel(HWSPINLOCK_NOTTAKEN, lock_addr);
+}
+
+/* The specs recommended below number as the retry delay time */
+static void sprd_hwspinlock_relax(struct hwspinlock *lock)
+{
+       ndelay(10);
+}
+
+static const struct hwspinlock_ops sprd_hwspinlock_ops = {
+       .trylock = sprd_hwspinlock_trylock,
+       .unlock = sprd_hwspinlock_unlock,
+       .relax = sprd_hwspinlock_relax,
+};
+
+static int sprd_hwspinlock_probe(struct platform_device *pdev)
+{
+       struct sprd_hwspinlock_dev *sprd_hwlock;
+       struct hwspinlock *lock;
+       struct resource *res;
+       int i, ret;
+
+       if (!pdev->dev.of_node)
+               return -ENODEV;
+
+       sprd_hwlock = devm_kzalloc(&pdev->dev,
+                                  sizeof(struct sprd_hwspinlock_dev) +
+                                  SPRD_HWLOCKS_NUM * sizeof(*lock),
+                                  GFP_KERNEL);
+       if (!sprd_hwlock)
+               return -ENOMEM;
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       sprd_hwlock->base = devm_ioremap_resource(&pdev->dev, res);
+       if (IS_ERR(sprd_hwlock->base))
+               return PTR_ERR(sprd_hwlock->base);
+
+       sprd_hwlock->clk = devm_clk_get(&pdev->dev, "enable");
+       if (IS_ERR(sprd_hwlock->clk)) {
+               dev_err(&pdev->dev, "get hwspinlock clock failed!\n");
+               return PTR_ERR(sprd_hwlock->clk);
+       }
+
+       clk_prepare_enable(sprd_hwlock->clk);
+
+       /* set the hwspinlock to record user id to identify subsystems */
+       writel(HWSPINLOCK_USER_BITS, sprd_hwlock->base + HWSPINLOCK_RECCTRL);
+
+       for (i = 0; i < SPRD_HWLOCKS_NUM; i++) {
+               lock = &sprd_hwlock->bank.lock[i];
+               lock->priv = sprd_hwlock->base + HWSPINLOCK_TOKEN(i);
+       }
+
+       platform_set_drvdata(pdev, sprd_hwlock);
+       pm_runtime_enable(&pdev->dev);
+
+       ret = hwspin_lock_register(&sprd_hwlock->bank, &pdev->dev,
+                                  &sprd_hwspinlock_ops, 0, SPRD_HWLOCKS_NUM);
+       if (ret) {
+               pm_runtime_disable(&pdev->dev);
+               clk_disable_unprepare(sprd_hwlock->clk);
+               return ret;
+       }
+
+       return 0;
+}
+
+static int sprd_hwspinlock_remove(struct platform_device *pdev)
+{
+       struct sprd_hwspinlock_dev *sprd_hwlock = platform_get_drvdata(pdev);
+
+       hwspin_lock_unregister(&sprd_hwlock->bank);
+       pm_runtime_disable(&pdev->dev);
+       clk_disable_unprepare(sprd_hwlock->clk);
+       return 0;
+}
+
+static const struct of_device_id sprd_hwspinlock_of_match[] = {
+       { .compatible = "sprd,hwspinlock-r3p0", },
+       { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, sprd_hwspinlock_of_match);
+
+static struct platform_driver sprd_hwspinlock_driver = {
+       .probe = sprd_hwspinlock_probe,
+       .remove = sprd_hwspinlock_remove,
+       .driver = {
+               .name = "sprd_hwspinlock",
+               .of_match_table = of_match_ptr(sprd_hwspinlock_of_match),
+       },
+};
+
+static int __init sprd_hwspinlock_init(void)
+{
+       return platform_driver_register(&sprd_hwspinlock_driver);
+}
+postcore_initcall(sprd_hwspinlock_init);
+
+static void __exit sprd_hwspinlock_exit(void)
+{
+       platform_driver_unregister(&sprd_hwspinlock_driver);
+}
+module_exit(sprd_hwspinlock_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Hardware spinlock driver for Spreadtrum");
+MODULE_AUTHOR("Baolin Wang <baolin.wang@spreadtrum.com>");
+MODULE_AUTHOR("Lanqing Liu <lanqing.liu@spreadtrum.com>");
+MODULE_AUTHOR("Long Cheng <aiden.cheng@spreadtrum.com>");