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 const struct hwspinlock_ops qcom_hwspinlock_ops = {
  68         .trylock        = qcom_hwspinlock_trylock,
  69         .unlock         = qcom_hwspinlock_unlock,
  70 };
  71
  72 static const struct regmap_config sfpb_mutex_config = {
  73         .reg_bits               = 32,
  74         .reg_stride             = 4,
  75         .val_bits               = 32,
  76         .max_register           = 0x100,
  77         .fast_io                = true,
  78 };
  79
  80 static const struct qcom_hwspinlock_of_data of_sfpb_mutex = {
  81         .offset = 0x4,
  82         .stride = 0x4,
  83         .regmap_config = &sfpb_mutex_config,
  84 };
  85
  86 static const struct regmap_config tcsr_msm8226_mutex_config = {
  87         .reg_bits               = 32,
  88         .reg_stride             = 4,
  89         .val_bits               = 32,
  90         .max_register           = 0x1000,
  91         .fast_io                = true,
  92 };
  93
  94 static const struct qcom_hwspinlock_of_data of_msm8226_tcsr_mutex = {
  95         .offset = 0,
  96         .stride = 0x80,
  97         .regmap_config = &tcsr_msm8226_mutex_config,
  98 };
  99
 100 static const struct regmap_config tcsr_mutex_config = {
 101         .reg_bits               = 32,
 102         .reg_stride             = 4,
 103         .val_bits               = 32,
 104         .max_register           = 0x20000,
 105         .fast_io                = true,
 106 };
 107
 108 static const struct qcom_hwspinlock_of_data of_tcsr_mutex = {
 109         .offset = 0,
 110         .stride = 0x1000,
 111         .regmap_config = &tcsr_mutex_config,
 112 };
 113
 114 static const struct of_device_id qcom_hwspinlock_of_match[] = {
 115         { .compatible = "qcom,sfpb-mutex", .data = &of_sfpb_mutex },
 116         { .compatible = "qcom,tcsr-mutex", .data = &of_tcsr_mutex },
 117         { .compatible = "qcom,apq8084-tcsr-mutex", .data = &of_msm8226_tcsr_mutex },
 118         { .compatible = "qcom,msm8226-tcsr-mutex", .data = &of_msm8226_tcsr_mutex },
 119         { .compatible = "qcom,msm8974-tcsr-mutex", .data = &of_msm8226_tcsr_mutex },
 120         { .compatible = "qcom,msm8994-tcsr-mutex", .data = &of_msm8226_tcsr_mutex },
 121         { }
 122 };
 123 MODULE_DEVICE_TABLE(of, qcom_hwspinlock_of_match);
 124
 125 static struct regmap *qcom_hwspinlock_probe_syscon(struct platform_device *pdev,
 126                                                    u32 *base, u32 *stride)
 127 {
 128         struct device_node *syscon;
 129         struct regmap *regmap;
 130         int ret;
 131
 132         syscon = of_parse_phandle(pdev->dev.of_node, "syscon", 0);
 133         if (!syscon)
 134                 return ERR_PTR(-ENODEV);
 135
 136         regmap = syscon_node_to_regmap(syscon);
 137         of_node_put(syscon);
 138         if (IS_ERR(regmap))
 139                 return regmap;
 140
 141         ret = of_property_read_u32_index(pdev->dev.of_node, "syscon", 1, base);
 142         if (ret < 0) {
 143                 dev_err(&pdev->dev, "no offset in syscon\n");
 144                 return ERR_PTR(-EINVAL);
 145         }
 146
 147         ret = of_property_read_u32_index(pdev->dev.of_node, "syscon", 2, stride);
 148         if (ret < 0) {
 149                 dev_err(&pdev->dev, "no stride syscon\n");
 150                 return ERR_PTR(-EINVAL);
 151         }
 152
 153         return regmap;
 154 }
 155
 156 static struct regmap *qcom_hwspinlock_probe_mmio(struct platform_device *pdev,
 157                                                  u32 *offset, u32 *stride)
 158 {
 159         const struct qcom_hwspinlock_of_data *data;
 160         struct device *dev = &pdev->dev;
 161         void __iomem *base;
 162
 163         data = of_device_get_match_data(dev);
 164         if (!data->regmap_config)
 165                 return ERR_PTR(-EINVAL);
 166
 167         *offset = data->offset;
 168         *stride = data->stride;
 169
 170         base = devm_platform_ioremap_resource(pdev, 0);
 171         if (IS_ERR(base))
 172                 return ERR_CAST(base);
 173
 174         return devm_regmap_init_mmio(dev, base, data->regmap_config);
 175 }
 176
 177 static int qcom_hwspinlock_probe(struct platform_device *pdev)
 178 {
 179         struct hwspinlock_device *bank;
 180         struct reg_field field;
 181         struct regmap *regmap;
 182         size_t array_size;
 183         u32 stride;
 184         u32 base;
 185         int i;
 186
 187         regmap = qcom_hwspinlock_probe_syscon(pdev, &base, &stride);
 188         if (IS_ERR(regmap) && PTR_ERR(regmap) == -ENODEV)
 189                 regmap = qcom_hwspinlock_probe_mmio(pdev, &base, &stride);
 190
 191         if (IS_ERR(regmap))
 192                 return PTR_ERR(regmap);
 193
 194         array_size = QCOM_MUTEX_NUM_LOCKS * sizeof(struct hwspinlock);
 195         bank = devm_kzalloc(&pdev->dev, sizeof(*bank) + array_size, GFP_KERNEL);
 196         if (!bank)
 197                 return -ENOMEM;
 198
 199         platform_set_drvdata(pdev, bank);
 200
 201         for (i = 0; i < QCOM_MUTEX_NUM_LOCKS; i++) {
 202                 field.reg = base + i * stride;
 203                 field.lsb = 0;
 204                 field.msb = 31;
 205
 206                 bank->lock[i].priv = devm_regmap_field_alloc(&pdev->dev,
 207                                                              regmap, field);
 208                 if (IS_ERR(bank->lock[i].priv))
 209                         return PTR_ERR(bank->lock[i].priv);
 210         }
 211
 212         return devm_hwspin_lock_register(&pdev->dev, bank, &qcom_hwspinlock_ops,
 213                                          0, QCOM_MUTEX_NUM_LOCKS);
 214 }
 215
 216 static struct platform_driver qcom_hwspinlock_driver = {
 217         .probe          = qcom_hwspinlock_probe,
 218         .driver         = {
 219                 .name   = "qcom_hwspinlock",
 220                 .of_match_table = qcom_hwspinlock_of_match,
 221         },
 222 };
 223
 224 static int __init qcom_hwspinlock_init(void)
 225 {
 226         return platform_driver_register(&qcom_hwspinlock_driver);
 227 }
 228 /* board init code might need to reserve hwspinlocks for predefined purposes */
 229 postcore_initcall(qcom_hwspinlock_init);
 230
 231 static void __exit qcom_hwspinlock_exit(void)
 232 {
 233         platform_driver_unregister(&qcom_hwspinlock_driver);
 234 }
 235 module_exit(qcom_hwspinlock_exit);
 236
 237 MODULE_LICENSE("GPL v2");
 238 MODULE_DESCRIPTION("Hardware spinlock driver for Qualcomm SoCs");