On 9/29/2014 10:35 PM, Bjorn Andersson wrote:
From: Kumar Gala <ga...@codeaurora.org>

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

Cc: Jeffrey Hugo <jh...@codeaurora.org>
Cc: Eric Holmberg <eholm...@codeaurora.org>
Cc: Courtney Cavin <courtney.ca...@sonymobile.com>
Signed-off-by: Kumar Gala <ga...@codeaurora.org>
[bjorn: added pm_runtime calls, from Courtney,
        added sfpb-mutex compatible,
        updated DT binding documentation formatting,
        replaced msm prefix with qcom,
        cleaned up includes]
Signed-off-by: Bjorn Andersson <bjorn.anders...@sonymobile.com>
---

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 v3:
  - Reverted back to getting stride from of_match, per Kumars request

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

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               |  151 ++++++++++++++++++++
  4 files changed, 198 insertions(+)
  create mode 100644 
Documentation/devicetree/bindings/hwlock/qcom-hwspinlock.txt
  create mode 100644 drivers/hwspinlock/qcom_hwspinlock.c


<snip>

+static int qcom_hwspinlock_probe(struct platform_device *pdev)
+{
+       struct device_node *node = pdev->dev.of_node;
+       const struct of_device_id *match;
+       struct hwspinlock_device *bank;
+       struct hwspinlock *hwlock;
+       struct resource *res;
+       void __iomem *iobase;
+       unsigned stride, i;
+       size_t array_size;
+       u32 num_locks;
+       int ret;
+
+       match = of_match_device(qcom_hwspinlock_of_match, &pdev->dev);
Didn't this have error handling in v2?
+
+       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 = (unsigned)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, &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 <ga...@codeaurora.org>");
+MODULE_AUTHOR("Jeffrey Hugo <jh...@codeaurora.org>");
+MODULE_AUTHOR("Eric Holmberg <eholm...@codeaurora.org>");



Jeffrey Hugo
--
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