1 /* 2 * Copyright (c) 2013, The Linux Foundation. All rights reserved. 3 * Copyright (c) 2015, Sony Mobile Communications AB 4 * 5 * This software is licensed under the terms of the GNU General Public 6 * License version 2, as published by the Free Software Foundation, and 7 * may be copied, distributed, and modified under those terms. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 */ 14 15 #include <linux/hwspinlock.h> 16 #include <linux/io.h> 17 #include <linux/kernel.h> 18 #include <linux/mfd/syscon.h> 19 #include <linux/module.h> 20 #include <linux/of.h> 21 #include <linux/of_device.h> 22 #include <linux/platform_device.h> 23 #include <linux/pm_runtime.h> 24 #include <linux/regmap.h> 25 26 #include "hwspinlock_internal.h" 27 28 #define QCOM_MUTEX_APPS_PROC_ID 1 29 #define QCOM_MUTEX_NUM_LOCKS 32 30 31 static int qcom_hwspinlock_trylock(struct hwspinlock *lock) 32 { 33 struct regmap_field *field = lock->priv; 34 u32 lock_owner; 35 int ret; 36 37 ret = regmap_field_write(field, QCOM_MUTEX_APPS_PROC_ID); 38 if (ret) 39 return ret; 40 41 ret = regmap_field_read(field, &lock_owner); 42 if (ret) 43 return ret; 44 45 return lock_owner == QCOM_MUTEX_APPS_PROC_ID; 46 } 47 48 static void qcom_hwspinlock_unlock(struct hwspinlock *lock) 49 { 50 struct regmap_field *field = lock->priv; 51 u32 lock_owner; 52 int ret; 53 54 ret = regmap_field_read(field, &lock_owner); 55 if (ret) { 56 pr_err("%s: unable to query spinlock owner\n", __func__); 57 return; 58 } 59 60 if (lock_owner != QCOM_MUTEX_APPS_PROC_ID) { 61 pr_err("%s: spinlock not owned by us (actual owner is %d)\n", 62 __func__, lock_owner); 63 } 64 65 ret = regmap_field_write(field, 0); 66 if (ret) 67 pr_err("%s: failed to unlock spinlock\n", __func__); 68 } 69 70 static const struct hwspinlock_ops qcom_hwspinlock_ops = { 71 .trylock = qcom_hwspinlock_trylock, 72 .unlock = qcom_hwspinlock_unlock, 73 }; 74 75 static const struct of_device_id qcom_hwspinlock_of_match[] = { 76 { .compatible = "qcom,sfpb-mutex" }, 77 { .compatible = "qcom,tcsr-mutex" }, 78 { } 79 }; 80 MODULE_DEVICE_TABLE(of, qcom_hwspinlock_of_match); 81 82 static int qcom_hwspinlock_probe(struct platform_device *pdev) 83 { 84 struct hwspinlock_device *bank; 85 struct device_node *syscon; 86 struct reg_field field; 87 struct regmap *regmap; 88 size_t array_size; 89 u32 stride; 90 u32 base; 91 int ret; 92 int i; 93 94 syscon = of_parse_phandle(pdev->dev.of_node, "syscon", 0); 95 if (!syscon) { 96 dev_err(&pdev->dev, "no syscon property\n"); 97 return -ENODEV; 98 } 99 100 regmap = syscon_node_to_regmap(syscon); 101 if (IS_ERR(regmap)) 102 return PTR_ERR(regmap); 103 104 ret = of_property_read_u32_index(pdev->dev.of_node, "syscon", 1, &base); 105 if (ret < 0) { 106 dev_err(&pdev->dev, "no offset in syscon\n"); 107 return -EINVAL; 108 } 109 110 ret = of_property_read_u32_index(pdev->dev.of_node, "syscon", 2, &stride); 111 if (ret < 0) { 112 dev_err(&pdev->dev, "no stride syscon\n"); 113 return -EINVAL; 114 } 115 116 array_size = QCOM_MUTEX_NUM_LOCKS * sizeof(struct hwspinlock); 117 bank = devm_kzalloc(&pdev->dev, sizeof(*bank) + array_size, GFP_KERNEL); 118 if (!bank) 119 return -ENOMEM; 120 121 platform_set_drvdata(pdev, bank); 122 123 for (i = 0; i < QCOM_MUTEX_NUM_LOCKS; i++) { 124 field.reg = base + i * stride; 125 field.lsb = 0; 126 field.msb = 31; 127 128 bank->lock[i].priv = devm_regmap_field_alloc(&pdev->dev, 129 regmap, field); 130 } 131 132 pm_runtime_enable(&pdev->dev); 133 134 ret = hwspin_lock_register(bank, &pdev->dev, &qcom_hwspinlock_ops, 135 0, QCOM_MUTEX_NUM_LOCKS); 136 if (ret) 137 pm_runtime_disable(&pdev->dev); 138 139 return ret; 140 } 141 142 static int qcom_hwspinlock_remove(struct platform_device *pdev) 143 { 144 struct hwspinlock_device *bank = platform_get_drvdata(pdev); 145 int ret; 146 147 ret = hwspin_lock_unregister(bank); 148 if (ret) { 149 dev_err(&pdev->dev, "%s failed: %d\n", __func__, ret); 150 return ret; 151 } 152 153 pm_runtime_disable(&pdev->dev); 154 155 return 0; 156 } 157 158 static struct platform_driver qcom_hwspinlock_driver = { 159 .probe = qcom_hwspinlock_probe, 160 .remove = qcom_hwspinlock_remove, 161 .driver = { 162 .name = "qcom_hwspinlock", 163 .of_match_table = qcom_hwspinlock_of_match, 164 }, 165 }; 166 167 static int __init qcom_hwspinlock_init(void) 168 { 169 return platform_driver_register(&qcom_hwspinlock_driver); 170 } 171 /* board init code might need to reserve hwspinlocks for predefined purposes */ 172 postcore_initcall(qcom_hwspinlock_init); 173 174 static void __exit qcom_hwspinlock_exit(void) 175 { 176 platform_driver_unregister(&qcom_hwspinlock_driver); 177 } 178 module_exit(qcom_hwspinlock_exit); 179 180 MODULE_LICENSE("GPL v2"); 181 MODULE_DESCRIPTION("Hardware spinlock driver for Qualcomm SoCs"); 182