/* * Copyright (c) 2013, The Linux Foundation. All rights reserved. * Copyright (c) 2015, 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/mfd/syscon.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/regmap.h> #include "hwspinlock_internal.h" #define QCOM_MUTEX_APPS_PROC_ID 1 #define QCOM_MUTEX_NUM_LOCKS 32 static int qcom_hwspinlock_trylock(struct hwspinlock *lock) { struct regmap_field *field = lock->priv; u32 lock_owner; int ret; ret = regmap_field_write(field, QCOM_MUTEX_APPS_PROC_ID); if (ret) return ret; ret = regmap_field_read(field, &lock_owner); if (ret) return ret; return lock_owner == QCOM_MUTEX_APPS_PROC_ID; } static void qcom_hwspinlock_unlock(struct hwspinlock *lock) { struct regmap_field *field = lock->priv; u32 lock_owner; int ret; ret = regmap_field_read(field, &lock_owner); if (ret) { pr_err("%s: unable to query spinlock owner\n", __func__); return; } if (lock_owner != QCOM_MUTEX_APPS_PROC_ID) { pr_err("%s: spinlock not owned by us (actual owner is %d)\n", __func__, lock_owner); } ret = regmap_field_write(field, 0); if (ret) pr_err("%s: failed to unlock spinlock\n", __func__); } 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 hwspinlock_device *bank; struct device_node *syscon; struct reg_field field; struct regmap *regmap; size_t array_size; u32 stride; u32 base; int ret; int i; syscon = of_parse_phandle(pdev->dev.of_node, "syscon", 0); if (!syscon) { dev_err(&pdev->dev, "no syscon property\n"); return -ENODEV; } regmap = syscon_node_to_regmap(syscon); of_node_put(syscon); if (IS_ERR(regmap)) return PTR_ERR(regmap); ret = of_property_read_u32_index(pdev->dev.of_node, "syscon", 1, &base); if (ret < 0) { dev_err(&pdev->dev, "no offset in syscon\n"); return -EINVAL; } ret = of_property_read_u32_index(pdev->dev.of_node, "syscon", 2, &stride); if (ret < 0) { dev_err(&pdev->dev, "no stride syscon\n"); return -EINVAL; } array_size = QCOM_MUTEX_NUM_LOCKS * sizeof(struct hwspinlock); bank = devm_kzalloc(&pdev->dev, sizeof(*bank) + array_size, GFP_KERNEL); if (!bank) return -ENOMEM; platform_set_drvdata(pdev, bank); for (i = 0; i < QCOM_MUTEX_NUM_LOCKS; i++) { field.reg = base + i * stride; field.lsb = 0; field.msb = 31; bank->lock[i].priv = devm_regmap_field_alloc(&pdev->dev, regmap, field); } pm_runtime_enable(&pdev->dev); ret = hwspin_lock_register(bank, &pdev->dev, &qcom_hwspinlock_ops, 0, QCOM_MUTEX_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");