diff options
Diffstat (limited to 'drivers/hwspinlock/qcom_hwspinlock.c')
| -rw-r--r-- | drivers/hwspinlock/qcom_hwspinlock.c | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/drivers/hwspinlock/qcom_hwspinlock.c b/drivers/hwspinlock/qcom_hwspinlock.c new file mode 100644 index 000000000000..c752447fbac7 --- /dev/null +++ b/drivers/hwspinlock/qcom_hwspinlock.c @@ -0,0 +1,181 @@ +/* + * 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); + 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"); |