drivers/hwspinlock/qcom_hwspinlock.c

   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 struct qcom_hwspinlock_of_data {
  23         u32 offset;
  24         u32 stride;
  25         const struct regmap_config *regmap_config;
  26 };
  27
  28 static int qcom_hwspinlock_trylock(struct hwspinlock *lock)
  29 {
  30         struct regmap_field *field = lock->priv;
  31         u32 lock_owner;
  32         int ret;
  33
  34         ret = regmap_field_write(field, QCOM_MUTEX_APPS_PROC_ID);
  35         if (ret)
  36                 return ret;
  37
  38         ret = regmap_field_read(field, &lock_owner);
  39         if (ret)
  40                 return ret;
  41
  42         return lock_owner == QCOM_MUTEX_APPS_PROC_ID;
  43 }
  44
  45 static void qcom_hwspinlock_unlock(struct hwspinlock *lock)
  46 {
  47         struct regmap_field *field = lock->priv;
  48         u32 lock_owner;
  49         int ret;
  50
  51         ret = regmap_field_read(field, &lock_owner);
  52         if (ret) {
  53                 pr_err("%s: unable to query spinlock owner\n", __func__);
  54                 return;
  55         }
  56
  57         if (lock_owner != QCOM_MUTEX_APPS_PROC_ID) {
  58                 pr_err("%s: spinlock not owned by us (actual owner is %d)\n",
  59                                 __func__, lock_owner);
  60         }
  61
  62         ret = regmap_field_write(field, 0);
  63         if (ret)
  64                 pr_err("%s: failed to unlock spinlock\n", __func__);
  65 }
  66
  67 static int qcom_hwspinlock_bust(struct hwspinlock *lock, unsigned int id)
  68 {
  69         struct regmap_field *field = lock->priv;
  70         u32 owner;
  71         int ret;
  72
  73         ret = regmap_field_read(field, &owner);
  74         if (ret) {
  75                 dev_err(lock->bank->dev, "unable to query spinlock owner\n");
  76                 return ret;
  77         }
  78
  79         if (owner != id)
  80                 return 0;
  81
  82         ret = regmap_field_write(field, 0);
  83         if (ret) {
  84                 dev_err(lock->bank->dev, "failed to bust spinlock\n");
  85                 return ret;
  86         }
  87
  88         return 0;
  89 }
  90
  91 static const struct hwspinlock_ops qcom_hwspinlock_ops = {
  92         .trylock        = qcom_hwspinlock_trylock,
  93         .unlock         = qcom_hwspinlock_unlock,
  94         .bust           = qcom_hwspinlock_bust,
  95 };
  96
  97 static const struct regmap_config sfpb_mutex_config = {
  98         .reg_bits               = 32,
  99         .reg_stride             = 4,
 100         .val_bits               = 32,
 101         .max_register           = 0x100,
 102         .fast_io                = true,
 103 };
 104
 105 static const struct qcom_hwspinlock_of_data of_sfpb_mutex = {
 106         .offset = 0x4,
 107         .stride = 0x4,
 108         .regmap_config = &sfpb_mutex_config,
 109 };
 110
 111 static const struct regmap_config tcsr_msm8226_mutex_config = {
 112         .reg_bits               = 32,
 113         .reg_stride             = 4,
 114         .val_bits               = 32,
 115         .max_register           = 0x1000,
 116         .fast_io                = true,
 117 };
 118
 119 static const struct qcom_hwspinlock_of_data of_msm8226_tcsr_mutex = {
 120         .offset = 0,
 121         .stride = 0x80,
 122         .regmap_config = &tcsr_msm8226_mutex_config,
 123 };
 124
 125 static const struct regmap_config tcsr_mutex_config = {
 126         .reg_bits               = 32,
 127         .reg_stride             = 4,
 128         .val_bits               = 32,
 129         .max_register           = 0x20000,
 130         .fast_io                = true,
 131 };
 132
 133 static const struct qcom_hwspinlock_of_data of_tcsr_mutex = {
 134         .offset = 0,
 135         .stride = 0x1000,
 136         .regmap_config = &tcsr_mutex_config,
 137 };
 138
 139 static const struct of_device_id qcom_hwspinlock_of_match[] = {
 140         { .compatible = "qcom,sfpb-mutex", .data = &of_sfpb_mutex },
 141         { .compatible = "qcom,tcsr-mutex", .data = &of_tcsr_mutex },
 142         { .compatible = "qcom,apq8084-tcsr-mutex", .data = &of_msm8226_tcsr_mutex },
 143         { .compatible = "qcom,msm8226-tcsr-mutex", .data = &of_msm8226_tcsr_mutex },
 144         { .compatible = "qcom,msm8974-tcsr-mutex", .data = &of_msm8226_tcsr_mutex },
 145         { .compatible = "qcom,msm8994-tcsr-mutex", .data = &of_msm8226_tcsr_mutex },
 146         { }
 147 };
 148 MODULE_DEVICE_TABLE(of, qcom_hwspinlock_of_match);
 149
 150 static struct regmap *qcom_hwspinlock_probe_syscon(struct platform_device *pdev,
 151                                                    u32 *base, u32 *stride)
 152 {
 153         struct device_node *syscon;
 154         struct regmap *regmap;
 155         int ret;
 156
 157         syscon = of_parse_phandle(pdev->dev.of_node, "syscon", 0);
 158         if (!syscon)
 159                 return ERR_PTR(-ENODEV);
 160
 161         regmap = syscon_node_to_regmap(syscon);
 162         of_node_put(syscon);
 163         if (IS_ERR(regmap))
 164                 return regmap;
 165
 166         ret = of_property_read_u32_index(pdev->dev.of_node, "syscon", 1, base);
 167         if (ret < 0) {
 168                 dev_err(&pdev->dev, "no offset in syscon\n");
 169                 return ERR_PTR(-EINVAL);
 170         }
 171
 172         ret = of_property_read_u32_index(pdev->dev.of_node, "syscon", 2, stride);
 173         if (ret < 0) {
 174                 dev_err(&pdev->dev, "no stride syscon\n");
 175                 return ERR_PTR(-EINVAL);
 176         }
 177
 178         return regmap;
 179 }
 180
 181 static struct regmap *qcom_hwspinlock_probe_mmio(struct platform_device *pdev,
 182                                                  u32 *offset, u32 *stride)
 183 {
 184         const struct qcom_hwspinlock_of_data *data;
 185         struct device *dev = &pdev->dev;
 186         void __iomem *base;
 187
 188         data = of_device_get_match_data(dev);
 189         if (!data->regmap_config)
 190                 return ERR_PTR(-EINVAL);
 191
 192         *offset = data->offset;
 193         *stride = data->stride;
 194
 195         base = devm_platform_ioremap_resource(pdev, 0);
 196         if (IS_ERR(base))
 197                 return ERR_CAST(base);
 198
 199         return devm_regmap_init_mmio(dev, base, data->regmap_config);
 200 }
 201
 202 static int qcom_hwspinlock_probe(struct platform_device *pdev)
 203 {
 204         struct hwspinlock_device *bank;
 205         struct reg_field field;
 206         struct regmap *regmap;
 207         size_t array_size;
 208         u32 stride;
 209         u32 base;
 210         int i;
 211
 212         regmap = qcom_hwspinlock_probe_syscon(pdev, &base, &stride);
 213         if (IS_ERR(regmap) && PTR_ERR(regmap) == -ENODEV)
 214                 regmap = qcom_hwspinlock_probe_mmio(pdev, &base, &stride);
 215
 216         if (IS_ERR(regmap))
 217                 return PTR_ERR(regmap);
 218
 219         array_size = QCOM_MUTEX_NUM_LOCKS * sizeof(struct hwspinlock);
 220         bank = devm_kzalloc(&pdev->dev, sizeof(*bank) + array_size, GFP_KERNEL);
 221         if (!bank)
 222                 return -ENOMEM;
 223
 224         platform_set_drvdata(pdev, bank);
 225
 226         for (i = 0; i < QCOM_MUTEX_NUM_LOCKS; i++) {
 227                 field.reg = base + i * stride;
 228                 field.lsb = 0;
 229                 field.msb = 31;
 230
 231                 bank->lock[i].priv = devm_regmap_field_alloc(&pdev->dev,
 232                                                              regmap, field);
 233                 if (IS_ERR(bank->lock[i].priv))
 234                         return PTR_ERR(bank->lock[i].priv);
 235         }
 236
 237         return devm_hwspin_lock_register(&pdev->dev, bank, &qcom_hwspinlock_ops,
 238                                          0, QCOM_MUTEX_NUM_LOCKS);
 239 }
 240
 241 static struct platform_driver qcom_hwspinlock_driver = {
 242         .probe          = qcom_hwspinlock_probe,
 243         .driver         = {
 244                 .name   = "qcom_hwspinlock",
 245                 .of_match_table = qcom_hwspinlock_of_match,
 246         },
 247 };
 248
 249 static int __init qcom_hwspinlock_init(void)
 250 {
 251         return platform_driver_register(&qcom_hwspinlock_driver);
 252 }
 253 /* board init code might need to reserve hwspinlocks for predefined purposes */
 254 postcore_initcall(qcom_hwspinlock_init);
 255
 256 static void __exit qcom_hwspinlock_exit(void)
 257 {
 258         platform_driver_unregister(&qcom_hwspinlock_driver);
 259 }
 260 module_exit(qcom_hwspinlock_exit);
 261
 262 MODULE_LICENSE("GPL v2");
 263 MODULE_DESCRIPTION("Hardware spinlock driver for Qualcomm SoCs");