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