On Sep 2, 2014, at 3:04 PM, Bjorn Andersson <Bjorn.Andersson@xxxxxxxxxxxxxx> wrote:
> From: Kumar Gala <galak@xxxxxxxxxxxxxx>
>
> Add driver for Qualcomm 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,
> based stride on resource size instead of hardcoded values,
> replaced msm prefix with qcom,
> cleaned up includes]
> 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 v2:
> - MODULE_DEVICE_TABLE
> - Changed prefix to qcom
> - Cleaned up includes
> - Rely on reg and num-locks to figure out stride, instead of of_match data
I know Jeff prefers this method of computing stride, but I’m not a fan as there isn’t a reason one could adjust qcom,num-locks in the dt for some reason and leave regs alone.
>
> 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/qcom-hwspinlock.txt | 35 +++++
> drivers/hwspinlock/Kconfig | 11 ++
> drivers/hwspinlock/Makefile | 1 +
> drivers/hwspinlock/qcom_hwspinlock.c | 147 ++++++++++++++++++++
> 4 files changed, 194 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/hwlock/qcom-hwspinlock.txt
> create mode 100644 drivers/hwspinlock/qcom_hwspinlock.c
>
> diff --git a/Documentation/devicetree/bindings/hwlock/qcom-hwspinlock.txt b/Documentation/devicetree/bindings/hwlock/qcom-hwspinlock.txt
> new file mode 100644
> index 0000000..27c7c80
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/hwlock/qcom-hwspinlock.txt
> @@ -0,0 +1,35 @@
> +Qualcomm 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”
I dont get the purpose of having different compatible strings if there is no difference in the code between them.
> +
> +- 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..af4c7e6 100644
> --- a/drivers/hwspinlock/Kconfig
> +++ b/drivers/hwspinlock/Kconfig
> @@ -8,6 +8,17 @@ config HWSPINLOCK
>
> menu "Hardware Spinlock drivers"
>
> +config HWSPINLOCK_QCOM
> + tristate "Qualcomm Hardware Spinlock device"
> + depends on ARCH_QCOM
> + select HWSPINLOCK
> + help
> + Say y here to support the Qualcomm 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..f3bff48 100644
> --- a/drivers/hwspinlock/Makefile
> +++ b/drivers/hwspinlock/Makefile
> @@ -3,5 +3,6 @@
> #
>
> obj-$(CONFIG_HWSPINLOCK) += hwspinlock_core.o
> +obj-$(CONFIG_HWSPINLOCK_QCOM) += qcom_hwspinlock.o
> obj-$(CONFIG_HWSPINLOCK_OMAP) += omap_hwspinlock.o
> obj-$(CONFIG_HSEM_U8500) += u8500_hsem.o
> diff --git a/drivers/hwspinlock/qcom_hwspinlock.c b/drivers/hwspinlock/qcom_hwspinlock.c
> new file mode 100644
> index 0000000..a9e5fa4
> --- /dev/null
> +++ b/drivers/hwspinlock/qcom_hwspinlock.c
> @@ -0,0 +1,147 @@
> +/*
> + * Copyright (c) 2013, The Linux Foundation. All rights reserved.
> + * Copyright (c) 2014, Sony Mobile Communications AB
> + *
> + * 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/hwspinlock.h>
> +#include <linux/io.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +
> +#include "hwspinlock_internal.h"
> +
> +#define SPINLOCK_ID_APPS_PROC 1
> +#define BASE_ID 0
> +
> +static int qcom_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 qcom_hwspinlock_unlock(struct hwspinlock *lock)
> +{
> + void __iomem *lock_addr = lock->priv;
> + u32 lock_owner;
> +
> + 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 qcom_hwspinlock_ops = {
> + .trylock = qcom_hwspinlock_trylock,
> + .unlock = qcom_hwspinlock_unlock,
> +};
> +
> +static const struct of_device_id qcom_hwspinlock_of_match[] = {
> + { .compatible = "qcom,sfpb-mutex" },
> + { .compatible = "qcom,tcsr-mutex" },
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, qcom_hwspinlock_of_match);
> +
> +static int qcom_hwspinlock_probe(struct platform_device *pdev)
> +{
> + struct device_node *node = pdev->dev.of_node;
> + struct hwspinlock_device *bank;
> + struct hwspinlock *hwlock;
> + struct resource *res;
> + void __iomem *iobase;
> + size_t array_size;
> + long stride, i;
> + u32 num_locks;
> + int ret;
> +
> + 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 = (long)resource_size(res) / num_locks;
> + 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, &qcom_hwspinlock_ops,
> + BASE_ID, num_locks);
> + if (ret)
> + pm_runtime_disable(&pdev->dev);
> +
> + return ret;
> +}
> +
> +static int qcom_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 qcom_hwspinlock_driver = {
> + .probe = qcom_hwspinlock_probe,
> + .remove = qcom_hwspinlock_remove,
> + .driver = {
> + .name = "qcom_hwspinlock",
> + .of_match_table = qcom_hwspinlock_of_match,
> + },
> +};
> +
> +static int __init qcom_hwspinlock_init(void)
> +{
> + return platform_driver_register(&qcom_hwspinlock_driver);
> +}
> +/* board init code might need to reserve hwspinlocks for predefined purposes */
> +postcore_initcall(qcom_hwspinlock_init);
> +
> +static void __exit qcom_hwspinlock_exit(void)
> +{
> + platform_driver_unregister(&qcom_hwspinlock_driver);
> +}
> +module_exit(qcom_hwspinlock_exit);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("Hardware spinlock driver for Qualcomm SoCs");
> +MODULE_AUTHOR("Kumar Gala <galak@xxxxxxxxxxxxxx>");
> +MODULE_AUTHOR("Jeffrey Hugo <jhugo@xxxxxxxxxxxxxx>");
> +MODULE_AUTHOR("Eric Holmberg <eholmber@xxxxxxxxxxxxxx>");
> --
> 1.7.9.5
>
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