[PATCH v2] hwspinlock/msm: Add support for Qualcomm MSM HW Mutex block

From: Bjorn Andersson
Date: Fri Aug 29 2014 - 19:14:37 EST


From: Kumar Gala <galak@xxxxxxxxxxxxxx>

Add driver for Qualcomm MSM Hardware Mutex block that exists on
newer Qualcomm SoCs.

Cc: Jeffrey Hugo <jhugo@xxxxxxxxxxxxxx>
Cc: Eric Holmberg <eholmber@xxxxxxxxxxxxxx>
Cc: Courtney Cavin <courtney.cavin@xxxxxxxxxxxxxx>
Signed-off-by: Kumar Gala <galak@xxxxxxxxxxxxxx>
[bjorn: added pm_runtime calls, from Courtney,
added sfpb-mutex compatible,
updated DT binding documentation formatting]
Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxxxxxx>
---

We need this driver to add support for the shared memory manager, so I'm
reviving Kumars patch from a year ago, with some additional sprinkles on top.

Changes since v1:
- Added the pm_runtime calls needed to be able to boot a kernel with
pm_runtime and this driver, patch from Courtney.
- Added sfpb-mutex compatible, for re-use of the driver in family A platforms.
- Updated formatting of DT binding documentation, while adding the extra
compatible.
- Dropped Stephen Boyds Reviewed-by due to these changes.

.../devicetree/bindings/hwlock/msm-hwspinlock.txt | 35 +++++
drivers/hwspinlock/Kconfig | 11 ++
drivers/hwspinlock/Makefile | 1 +
drivers/hwspinlock/msm_hwspinlock.c | 155 +++++++++++++++++++++
4 files changed, 202 insertions(+)
create mode 100644 Documentation/devicetree/bindings/hwlock/msm-hwspinlock.txt
create mode 100644 drivers/hwspinlock/msm_hwspinlock.c

diff --git a/Documentation/devicetree/bindings/hwlock/msm-hwspinlock.txt b/Documentation/devicetree/bindings/hwlock/msm-hwspinlock.txt
new file mode 100644
index 0000000..65d9ab0
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwlock/msm-hwspinlock.txt
@@ -0,0 +1,35 @@
+Qualcomm MSM Hardware Mutex Block:
+
+The hardware block provides mutexes utilized between different processors
+on the SoC as part of the communication protocol used by these processors.
+
+- compatible:
+ Usage: required
+ Value type: <string>
+ Definition: must be one of:
+ "qcom,sfpb-mutex",
+ "qcom,tcsr-mutex"
+
+- reg:
+ Usage: required
+ Value type: <prop-encoded-array>
+ Definition: base address and size of the mutex registers
+
+- reg-names:
+ Usage: required
+ Value type: <string>
+ Definition: must be "mutex-base"
+
+- qcom,num-locks:
+ Usage: required
+ Value type: <u32>
+ Definition: the number of locks/mutex available in this block
+
+Example:
+
+ hwlock@fd484000 {
+ compatible = "qcom,tcsr-mutex";
+ reg = <0xfd484000 0x1000>;
+ reg-names = "mutex-base";
+ qcom,num-locks = <32>;
+ };
diff --git a/drivers/hwspinlock/Kconfig b/drivers/hwspinlock/Kconfig
index 3612cb5..2cd39e2 100644
--- a/drivers/hwspinlock/Kconfig
+++ b/drivers/hwspinlock/Kconfig
@@ -8,6 +8,17 @@ config HWSPINLOCK

menu "Hardware Spinlock drivers"

+config HWSPINLOCK_MSM
+ tristate "MSM Hardware Spinlock device"
+ depends on ARCH_QCOM
+ select HWSPINLOCK
+ help
+ Say y here to support the MSM Hardware Mutex functionality, which
+ provides a synchronisation mechanism for the various processors on
+ the SoC.
+
+ If unsure, say N.
+
config HWSPINLOCK_OMAP
tristate "OMAP Hardware Spinlock device"
depends on ARCH_OMAP4 || SOC_OMAP5 || SOC_DRA7XX || SOC_AM33XX || SOC_AM43XX
diff --git a/drivers/hwspinlock/Makefile b/drivers/hwspinlock/Makefile
index 93eb64b..4074c56 100644
--- a/drivers/hwspinlock/Makefile
+++ b/drivers/hwspinlock/Makefile
@@ -3,5 +3,6 @@
#

obj-$(CONFIG_HWSPINLOCK) += hwspinlock_core.o
+obj-$(CONFIG_HWSPINLOCK_MSM) += msm_hwspinlock.o
obj-$(CONFIG_HWSPINLOCK_OMAP) += omap_hwspinlock.o
obj-$(CONFIG_HSEM_U8500) += u8500_hsem.o
diff --git a/drivers/hwspinlock/msm_hwspinlock.c b/drivers/hwspinlock/msm_hwspinlock.c
new file mode 100644
index 0000000..9ddd020
--- /dev/null
+++ b/drivers/hwspinlock/msm_hwspinlock.c
@@ -0,0 +1,155 @@
+/*
+ * Copyright (c) 2013, The Linux Foundation. All rights reserved.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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/err.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/hwspinlock.h>
+#include <linux/io.h>
+
+#include "hwspinlock_internal.h"
+
+#define SPINLOCK_ID_APPS_PROC 1
+#define BASE_ID 0
+
+static int msm_hwspinlock_trylock(struct hwspinlock *lock)
+{
+ void __iomem *lock_addr = lock->priv;
+
+ writel_relaxed(SPINLOCK_ID_APPS_PROC, lock_addr);
+
+ return readl_relaxed(lock_addr) == SPINLOCK_ID_APPS_PROC;
+}
+
+static void msm_hwspinlock_unlock(struct hwspinlock *lock)
+{
+ u32 lock_owner;
+ void __iomem *lock_addr = lock->priv;
+
+ lock_owner = readl_relaxed(lock_addr);
+ if (lock_owner != SPINLOCK_ID_APPS_PROC) {
+ pr_err("%s: spinlock not owned by us (actual owner is %d)\n",
+ __func__, lock_owner);
+ }
+
+ writel_relaxed(0, lock_addr);
+}
+
+static const struct hwspinlock_ops msm_hwspinlock_ops = {
+ .trylock = msm_hwspinlock_trylock,
+ .unlock = msm_hwspinlock_unlock,
+};
+
+static const struct of_device_id msm_hwspinlock_of_match[] = {
+ { .compatible = "qcom,sfpb-mutex", .data = (void *)0x4 },
+ { .compatible = "qcom,tcsr-mutex", .data = (void *)0x80 },
+ { },
+};
+
+static int msm_hwspinlock_probe(struct platform_device *pdev)
+{
+ int ret, i, stride;
+ size_t array_size;
+ u32 num_locks;
+ struct hwspinlock_device *bank;
+ struct hwspinlock *hwlock;
+ struct resource *res;
+ void __iomem *iobase;
+ struct device_node *node = pdev->dev.of_node;
+ const struct of_device_id *match;
+
+ match = of_match_device(msm_hwspinlock_of_match, &pdev->dev);
+ if (!match)
+ return -EINVAL;
+
+ ret = of_property_read_u32(node, "qcom,num-locks", &num_locks);
+ if (ret || num_locks == 0)
+ return -ENODEV;
+
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mutex-base");
+ iobase = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(iobase))
+ return PTR_ERR(iobase);
+
+ array_size = num_locks * sizeof(*hwlock);
+ bank = devm_kzalloc(&pdev->dev, sizeof(*bank) + array_size, GFP_KERNEL);
+ if (!bank)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, bank);
+
+ stride = (int)match->data;
+ for (i = 0, hwlock = &bank->lock[0]; i < num_locks; i++, hwlock++)
+ hwlock->priv = iobase + i * stride;
+
+ pm_runtime_enable(&pdev->dev);
+
+ ret = hwspin_lock_register(bank, &pdev->dev, &msm_hwspinlock_ops,
+ BASE_ID, num_locks);
+ if (ret)
+ pm_runtime_disable(&pdev->dev);
+
+ return ret;
+}
+
+static int msm_hwspinlock_remove(struct platform_device *pdev)
+{
+ struct hwspinlock_device *bank = platform_get_drvdata(pdev);
+ int ret;
+
+ ret = hwspin_lock_unregister(bank);
+ if (ret) {
+ dev_err(&pdev->dev, "%s failed: %d\n", __func__, ret);
+ return ret;
+ }
+
+ pm_runtime_disable(&pdev->dev);
+
+ return 0;
+}
+
+static struct platform_driver msm_hwspinlock_driver = {
+ .probe = msm_hwspinlock_probe,
+ .remove = msm_hwspinlock_remove,
+ .driver = {
+ .name = "msm_hwspinlock",
+ .owner = THIS_MODULE,
+ .of_match_table = msm_hwspinlock_of_match,
+ },
+};
+
+static int __init msm_hwspinlock_init(void)
+{
+ return platform_driver_register(&msm_hwspinlock_driver);
+}
+/* board init code might need to reserve hwspinlocks for predefined purposes */
+postcore_initcall(msm_hwspinlock_init);
+
+static void __exit msm_hwspinlock_exit(void)
+{
+ platform_driver_unregister(&msm_hwspinlock_driver);
+}
+module_exit(msm_hwspinlock_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Hardware spinlock driver for MSM");
+MODULE_AUTHOR("Kumar Gala <galak@xxxxxxxxxxxxxx>");
+MODULE_AUTHOR("Jeffrey Hugo <jhugo@xxxxxxxxxxxxxx>");
+MODULE_AUTHOR("Eric Holmberg <eholmber@xxxxxxxxxxxxxx>");
--
1.8.2.2

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