drivers/hwspinlock/qcom_hwspinlock.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * Copyright (c) 2013, The Linux Foundation. All rights reserved.
0004  * Copyright (c) 2015, Sony Mobile Communications AB
0005  */
0006
0007 #include <linux/hwspinlock.h>
0008 #include <linux/io.h>
0009 #include <linux/kernel.h>
0010 #include <linux/mfd/syscon.h>
0011 #include <linux/module.h>
0012 #include <linux/of.h>
0013 #include <linux/of_device.h>
0014 #include <linux/platform_device.h>
0015 #include <linux/regmap.h>
0016
0017 #include "hwspinlock_internal.h"
0018
0019 #define QCOM_MUTEX_APPS_PROC_ID 1
0020 #define QCOM_MUTEX_NUM_LOCKS    32
0021
0022 struct qcom_hwspinlock_of_data {
0023     u32 offset;
0024     u32 stride;
0025 };
0026
0027 static int qcom_hwspinlock_trylock(struct hwspinlock *lock)
0028 {
0029     struct regmap_field *field = lock->priv;
0030     u32 lock_owner;
0031     int ret;
0032
0033     ret = regmap_field_write(field, QCOM_MUTEX_APPS_PROC_ID);
0034     if (ret)
0035         return ret;
0036
0037     ret = regmap_field_read(field, &lock_owner);
0038     if (ret)
0039         return ret;
0040
0041     return lock_owner == QCOM_MUTEX_APPS_PROC_ID;
0042 }
0043
0044 static void qcom_hwspinlock_unlock(struct hwspinlock *lock)
0045 {
0046     struct regmap_field *field = lock->priv;
0047     u32 lock_owner;
0048     int ret;
0049
0050     ret = regmap_field_read(field, &lock_owner);
0051     if (ret) {
0052         pr_err("%s: unable to query spinlock owner\n", __func__);
0053         return;
0054     }
0055
0056     if (lock_owner != QCOM_MUTEX_APPS_PROC_ID) {
0057         pr_err("%s: spinlock not owned by us (actual owner is %d)\n",
0058                 __func__, lock_owner);
0059     }
0060
0061     ret = regmap_field_write(field, 0);
0062     if (ret)
0063         pr_err("%s: failed to unlock spinlock\n", __func__);
0064 }
0065
0066 static const struct hwspinlock_ops qcom_hwspinlock_ops = {
0067     .trylock    = qcom_hwspinlock_trylock,
0068     .unlock     = qcom_hwspinlock_unlock,
0069 };
0070
0071 static const struct qcom_hwspinlock_of_data of_sfpb_mutex = {
0072     .offset = 0x4,
0073     .stride = 0x4,
0074 };
0075
0076 /* All modern platform has offset 0 and stride of 4k */
0077 static const struct qcom_hwspinlock_of_data of_tcsr_mutex = {
0078     .offset = 0,
0079     .stride = 0x1000,
0080 };
0081
0082 static const struct of_device_id qcom_hwspinlock_of_match[] = {
0083     { .compatible = "qcom,sfpb-mutex", .data = &of_sfpb_mutex },
0084     { .compatible = "qcom,tcsr-mutex", .data = &of_tcsr_mutex },
0085     { }
0086 };
0087 MODULE_DEVICE_TABLE(of, qcom_hwspinlock_of_match);
0088
0089 static struct regmap *qcom_hwspinlock_probe_syscon(struct platform_device *pdev,
0090                            u32 *base, u32 *stride)
0091 {
0092     struct device_node *syscon;
0093     struct regmap *regmap;
0094     int ret;
0095
0096     syscon = of_parse_phandle(pdev->dev.of_node, "syscon", 0);
0097     if (!syscon)
0098         return ERR_PTR(-ENODEV);
0099
0100     regmap = syscon_node_to_regmap(syscon);
0101     of_node_put(syscon);
0102     if (IS_ERR(regmap))
0103         return regmap;
0104
0105     ret = of_property_read_u32_index(pdev->dev.of_node, "syscon", 1, base);
0106     if (ret < 0) {
0107         dev_err(&pdev->dev, "no offset in syscon\n");
0108         return ERR_PTR(-EINVAL);
0109     }
0110
0111     ret = of_property_read_u32_index(pdev->dev.of_node, "syscon", 2, stride);
0112     if (ret < 0) {
0113         dev_err(&pdev->dev, "no stride syscon\n");
0114         return ERR_PTR(-EINVAL);
0115     }
0116
0117     return regmap;
0118 }
0119
0120 static const struct regmap_config tcsr_mutex_config = {
0121     .reg_bits       = 32,
0122     .reg_stride     = 4,
0123     .val_bits       = 32,
0124     .max_register       = 0x40000,
0125     .fast_io        = true,
0126 };
0127
0128 static struct regmap *qcom_hwspinlock_probe_mmio(struct platform_device *pdev,
0129                          u32 *offset, u32 *stride)
0130 {
0131     const struct qcom_hwspinlock_of_data *data;
0132     struct device *dev = &pdev->dev;
0133     void __iomem *base;
0134
0135     data = of_device_get_match_data(dev);
0136
0137     *offset = data->offset;
0138     *stride = data->stride;
0139
0140     base = devm_platform_ioremap_resource(pdev, 0);
0141     if (IS_ERR(base))
0142         return ERR_CAST(base);
0143
0144     return devm_regmap_init_mmio(dev, base, &tcsr_mutex_config);
0145 }
0146
0147 static int qcom_hwspinlock_probe(struct platform_device *pdev)
0148 {
0149     struct hwspinlock_device *bank;
0150     struct reg_field field;
0151     struct regmap *regmap;
0152     size_t array_size;
0153     u32 stride;
0154     u32 base;
0155     int i;
0156
0157     regmap = qcom_hwspinlock_probe_syscon(pdev, &base, &stride);
0158     if (IS_ERR(regmap) && PTR_ERR(regmap) == -ENODEV)
0159         regmap = qcom_hwspinlock_probe_mmio(pdev, &base, &stride);
0160
0161     if (IS_ERR(regmap))
0162         return PTR_ERR(regmap);
0163
0164     array_size = QCOM_MUTEX_NUM_LOCKS * sizeof(struct hwspinlock);
0165     bank = devm_kzalloc(&pdev->dev, sizeof(*bank) + array_size, GFP_KERNEL);
0166     if (!bank)
0167         return -ENOMEM;
0168
0169     platform_set_drvdata(pdev, bank);
0170
0171     for (i = 0; i < QCOM_MUTEX_NUM_LOCKS; i++) {
0172         field.reg = base + i * stride;
0173         field.lsb = 0;
0174         field.msb = 31;
0175
0176         bank->lock[i].priv = devm_regmap_field_alloc(&pdev->dev,
0177                                  regmap, field);
0178     }
0179
0180     return devm_hwspin_lock_register(&pdev->dev, bank, &qcom_hwspinlock_ops,
0181                      0, QCOM_MUTEX_NUM_LOCKS);
0182 }
0183
0184 static struct platform_driver qcom_hwspinlock_driver = {
0185     .probe      = qcom_hwspinlock_probe,
0186     .driver     = {
0187         .name   = "qcom_hwspinlock",
0188         .of_match_table = qcom_hwspinlock_of_match,
0189     },
0190 };
0191
0192 static int __init qcom_hwspinlock_init(void)
0193 {
0194     return platform_driver_register(&qcom_hwspinlock_driver);
0195 }
0196 /* board init code might need to reserve hwspinlocks for predefined purposes */
0197 postcore_initcall(qcom_hwspinlock_init);
0198
0199 static void __exit qcom_hwspinlock_exit(void)
0200 {
0201     platform_driver_unregister(&qcom_hwspinlock_driver);
0202 }
0203 module_exit(qcom_hwspinlock_exit);
0204
0205 MODULE_LICENSE("GPL v2");
0206 MODULE_DESCRIPTION("Hardware spinlock driver for Qualcomm SoCs");