1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (c) 2013, The Linux Foundation. All rights reserved. 4 * Copyright (c) 2015, Sony Mobile Communications AB 5 */ 6 7 #include <linux/hwspinlock.h> 8 #include <linux/io.h> 9 #include <linux/kernel.h> 10 #include <linux/mfd/syscon.h> 11 #include <linux/module.h> 12 #include <linux/of.h> 13 #include <linux/of_device.h> 14 #include <linux/platform_device.h> 15 #include <linux/pm_runtime.h> 16 #include <linux/regmap.h> 17 18 #include "hwspinlock_internal.h" 19 20 #define QCOM_MUTEX_APPS_PROC_ID 1 21 #define QCOM_MUTEX_NUM_LOCKS 32 22 23 static int qcom_hwspinlock_trylock(struct hwspinlock *lock) 24 { 25 struct regmap_field *field = lock->priv; 26 u32 lock_owner; 27 int ret; 28 29 ret = regmap_field_write(field, QCOM_MUTEX_APPS_PROC_ID); 30 if (ret) 31 return ret; 32 33 ret = regmap_field_read(field, &lock_owner); 34 if (ret) 35 return ret; 36 37 return lock_owner == QCOM_MUTEX_APPS_PROC_ID; 38 } 39 40 static void qcom_hwspinlock_unlock(struct hwspinlock *lock) 41 { 42 struct regmap_field *field = lock->priv; 43 u32 lock_owner; 44 int ret; 45 46 ret = regmap_field_read(field, &lock_owner); 47 if (ret) { 48 pr_err("%s: unable to query spinlock owner\n", __func__); 49 return; 50 } 51 52 if (lock_owner != QCOM_MUTEX_APPS_PROC_ID) { 53 pr_err("%s: spinlock not owned by us (actual owner is %d)\n", 54 __func__, lock_owner); 55 } 56 57 ret = regmap_field_write(field, 0); 58 if (ret) 59 pr_err("%s: failed to unlock spinlock\n", __func__); 60 } 61 62 static const struct hwspinlock_ops qcom_hwspinlock_ops = { 63 .trylock = qcom_hwspinlock_trylock, 64 .unlock = qcom_hwspinlock_unlock, 65 }; 66 67 static const struct of_device_id qcom_hwspinlock_of_match[] = { 68 { .compatible = "qcom,sfpb-mutex" }, 69 { .compatible = "qcom,tcsr-mutex" }, 70 { } 71 }; 72 MODULE_DEVICE_TABLE(of, qcom_hwspinlock_of_match); 73 74 static int qcom_hwspinlock_probe(struct platform_device *pdev) 75 { 76 struct hwspinlock_device *bank; 77 struct device_node *syscon; 78 struct reg_field field; 79 struct regmap *regmap; 80 size_t array_size; 81 u32 stride; 82 u32 base; 83 int ret; 84 int i; 85 86 syscon = of_parse_phandle(pdev->dev.of_node, "syscon", 0); 87 if (!syscon) { 88 dev_err(&pdev->dev, "no syscon property\n"); 89 return -ENODEV; 90 } 91 92 regmap = syscon_node_to_regmap(syscon); 93 of_node_put(syscon); 94 if (IS_ERR(regmap)) 95 return PTR_ERR(regmap); 96 97 ret = of_property_read_u32_index(pdev->dev.of_node, "syscon", 1, &base); 98 if (ret < 0) { 99 dev_err(&pdev->dev, "no offset in syscon\n"); 100 return -EINVAL; 101 } 102 103 ret = of_property_read_u32_index(pdev->dev.of_node, "syscon", 2, &stride); 104 if (ret < 0) { 105 dev_err(&pdev->dev, "no stride syscon\n"); 106 return -EINVAL; 107 } 108 109 array_size = QCOM_MUTEX_NUM_LOCKS * sizeof(struct hwspinlock); 110 bank = devm_kzalloc(&pdev->dev, sizeof(*bank) + array_size, GFP_KERNEL); 111 if (!bank) 112 return -ENOMEM; 113 114 platform_set_drvdata(pdev, bank); 115 116 for (i = 0; i < QCOM_MUTEX_NUM_LOCKS; i++) { 117 field.reg = base + i * stride; 118 field.lsb = 0; 119 field.msb = 31; 120 121 bank->lock[i].priv = devm_regmap_field_alloc(&pdev->dev, 122 regmap, field); 123 } 124 125 pm_runtime_enable(&pdev->dev); 126 127 ret = hwspin_lock_register(bank, &pdev->dev, &qcom_hwspinlock_ops, 128 0, QCOM_MUTEX_NUM_LOCKS); 129 if (ret) 130 pm_runtime_disable(&pdev->dev); 131 132 return ret; 133 } 134 135 static int qcom_hwspinlock_remove(struct platform_device *pdev) 136 { 137 struct hwspinlock_device *bank = platform_get_drvdata(pdev); 138 int ret; 139 140 ret = hwspin_lock_unregister(bank); 141 if (ret) { 142 dev_err(&pdev->dev, "%s failed: %d\n", __func__, ret); 143 return ret; 144 } 145 146 pm_runtime_disable(&pdev->dev); 147 148 return 0; 149 } 150 151 static struct platform_driver qcom_hwspinlock_driver = { 152 .probe = qcom_hwspinlock_probe, 153 .remove = qcom_hwspinlock_remove, 154 .driver = { 155 .name = "qcom_hwspinlock", 156 .of_match_table = qcom_hwspinlock_of_match, 157 }, 158 }; 159 160 static int __init qcom_hwspinlock_init(void) 161 { 162 return platform_driver_register(&qcom_hwspinlock_driver); 163 } 164 /* board init code might need to reserve hwspinlocks for predefined purposes */ 165 postcore_initcall(qcom_hwspinlock_init); 166 167 static void __exit qcom_hwspinlock_exit(void) 168 { 169 platform_driver_unregister(&qcom_hwspinlock_driver); 170 } 171 module_exit(qcom_hwspinlock_exit); 172 173 MODULE_LICENSE("GPL v2"); 174 MODULE_DESCRIPTION("Hardware spinlock driver for Qualcomm SoCs"); 175