linux/drivers/misc/cb710/core.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 *  cb710/core.c
   4 *
   5 *  Copyright by Michał Mirosław, 2008-2009
   6 */
   7#include <linux/kernel.h>
   8#include <linux/module.h>
   9#include <linux/pci.h>
  10#include <linux/spinlock.h>
  11#include <linux/idr.h>
  12#include <linux/cb710.h>
  13#include <linux/gfp.h>
  14
  15static DEFINE_IDA(cb710_ida);
  16
  17void cb710_pci_update_config_reg(struct pci_dev *pdev,
  18        int reg, uint32_t mask, uint32_t xor)
  19{
  20        u32 rval;
  21
  22        pci_read_config_dword(pdev, reg, &rval);
  23        rval = (rval & mask) ^ xor;
  24        pci_write_config_dword(pdev, reg, rval);
  25}
  26EXPORT_SYMBOL_GPL(cb710_pci_update_config_reg);
  27
  28/* Some magic writes based on Windows driver init code */
  29static int cb710_pci_configure(struct pci_dev *pdev)
  30{
  31        unsigned int devfn = PCI_DEVFN(PCI_SLOT(pdev->devfn), 0);
  32        struct pci_dev *pdev0;
  33        u32 val;
  34
  35        cb710_pci_update_config_reg(pdev, 0x48,
  36                ~0x000000FF, 0x0000003F);
  37
  38        pci_read_config_dword(pdev, 0x48, &val);
  39        if (val & 0x80000000)
  40                return 0;
  41
  42        pdev0 = pci_get_slot(pdev->bus, devfn);
  43        if (!pdev0)
  44                return -ENODEV;
  45
  46        if (pdev0->vendor == PCI_VENDOR_ID_ENE
  47            && pdev0->device == PCI_DEVICE_ID_ENE_720) {
  48                cb710_pci_update_config_reg(pdev0, 0x8C,
  49                        ~0x00F00000, 0x00100000);
  50                cb710_pci_update_config_reg(pdev0, 0xB0,
  51                        ~0x08000000, 0x08000000);
  52        }
  53
  54        cb710_pci_update_config_reg(pdev0, 0x8C,
  55                ~0x00000F00, 0x00000200);
  56        cb710_pci_update_config_reg(pdev0, 0x90,
  57                ~0x00060000, 0x00040000);
  58
  59        pci_dev_put(pdev0);
  60
  61        return 0;
  62}
  63
  64static irqreturn_t cb710_irq_handler(int irq, void *data)
  65{
  66        struct cb710_chip *chip = data;
  67        struct cb710_slot *slot = &chip->slot[0];
  68        irqreturn_t handled = IRQ_NONE;
  69        unsigned nr;
  70
  71        spin_lock(&chip->irq_lock); /* incl. smp_rmb() */
  72
  73        for (nr = chip->slots; nr; ++slot, --nr) {
  74                cb710_irq_handler_t handler_func = slot->irq_handler;
  75                if (handler_func && handler_func(slot))
  76                        handled = IRQ_HANDLED;
  77        }
  78
  79        spin_unlock(&chip->irq_lock);
  80
  81        return handled;
  82}
  83
  84static void cb710_release_slot(struct device *dev)
  85{
  86#ifdef CONFIG_CB710_DEBUG_ASSUMPTIONS
  87        struct cb710_slot *slot = cb710_pdev_to_slot(to_platform_device(dev));
  88        struct cb710_chip *chip = cb710_slot_to_chip(slot);
  89
  90        /* slot struct can be freed now */
  91        atomic_dec(&chip->slot_refs_count);
  92#endif
  93}
  94
  95static int cb710_register_slot(struct cb710_chip *chip,
  96        unsigned slot_mask, unsigned io_offset, const char *name)
  97{
  98        int nr = chip->slots;
  99        struct cb710_slot *slot = &chip->slot[nr];
 100        int err;
 101
 102        dev_dbg(cb710_chip_dev(chip),
 103                "register: %s.%d; slot %d; mask %d; IO offset: 0x%02X\n",
 104                name, chip->platform_id, nr, slot_mask, io_offset);
 105
 106        /* slot->irq_handler == NULL here; this needs to be
 107         * seen before platform_device_register() */
 108        ++chip->slots;
 109        smp_wmb();
 110
 111        slot->iobase = chip->iobase + io_offset;
 112        slot->pdev.name = name;
 113        slot->pdev.id = chip->platform_id;
 114        slot->pdev.dev.parent = &chip->pdev->dev;
 115        slot->pdev.dev.release = cb710_release_slot;
 116
 117        err = platform_device_register(&slot->pdev);
 118
 119#ifdef CONFIG_CB710_DEBUG_ASSUMPTIONS
 120        atomic_inc(&chip->slot_refs_count);
 121#endif
 122
 123        if (err) {
 124                /* device_initialize() called from platform_device_register()
 125                 * wants this on error path */
 126                platform_device_put(&slot->pdev);
 127
 128                /* slot->irq_handler == NULL here anyway, so no lock needed */
 129                --chip->slots;
 130                return err;
 131        }
 132
 133        chip->slot_mask |= slot_mask;
 134
 135        return 0;
 136}
 137
 138static void cb710_unregister_slot(struct cb710_chip *chip,
 139        unsigned slot_mask)
 140{
 141        int nr = chip->slots - 1;
 142
 143        if (!(chip->slot_mask & slot_mask))
 144                return;
 145
 146        platform_device_unregister(&chip->slot[nr].pdev);
 147
 148        /* complementary to spin_unlock() in cb710_set_irq_handler() */
 149        smp_rmb();
 150        BUG_ON(chip->slot[nr].irq_handler != NULL);
 151
 152        /* slot->irq_handler == NULL here, so no lock needed */
 153        --chip->slots;
 154        chip->slot_mask &= ~slot_mask;
 155}
 156
 157void cb710_set_irq_handler(struct cb710_slot *slot,
 158        cb710_irq_handler_t handler)
 159{
 160        struct cb710_chip *chip = cb710_slot_to_chip(slot);
 161        unsigned long flags;
 162
 163        spin_lock_irqsave(&chip->irq_lock, flags);
 164        slot->irq_handler = handler;
 165        spin_unlock_irqrestore(&chip->irq_lock, flags);
 166}
 167EXPORT_SYMBOL_GPL(cb710_set_irq_handler);
 168
 169static int __maybe_unused cb710_suspend(struct device *dev_d)
 170{
 171        struct pci_dev *pdev = to_pci_dev(dev_d);
 172        struct cb710_chip *chip = pci_get_drvdata(pdev);
 173
 174        devm_free_irq(&pdev->dev, pdev->irq, chip);
 175        return 0;
 176}
 177
 178static int __maybe_unused cb710_resume(struct device *dev_d)
 179{
 180        struct pci_dev *pdev = to_pci_dev(dev_d);
 181        struct cb710_chip *chip = pci_get_drvdata(pdev);
 182
 183        return devm_request_irq(&pdev->dev, pdev->irq,
 184                cb710_irq_handler, IRQF_SHARED, KBUILD_MODNAME, chip);
 185}
 186
 187static int cb710_probe(struct pci_dev *pdev,
 188        const struct pci_device_id *ent)
 189{
 190        struct cb710_chip *chip;
 191        u32 val;
 192        int err;
 193        int n = 0;
 194
 195        err = cb710_pci_configure(pdev);
 196        if (err)
 197                return err;
 198
 199        /* this is actually magic... */
 200        pci_read_config_dword(pdev, 0x48, &val);
 201        if (!(val & 0x80000000)) {
 202                pci_write_config_dword(pdev, 0x48, val|0x71000000);
 203                pci_read_config_dword(pdev, 0x48, &val);
 204        }
 205
 206        dev_dbg(&pdev->dev, "PCI config[0x48] = 0x%08X\n", val);
 207        if (!(val & 0x70000000))
 208                return -ENODEV;
 209        val = (val >> 28) & 7;
 210        if (val & CB710_SLOT_MMC)
 211                ++n;
 212        if (val & CB710_SLOT_MS)
 213                ++n;
 214        if (val & CB710_SLOT_SM)
 215                ++n;
 216
 217        chip = devm_kzalloc(&pdev->dev, struct_size(chip, slot, n),
 218                            GFP_KERNEL);
 219        if (!chip)
 220                return -ENOMEM;
 221
 222        err = pcim_enable_device(pdev);
 223        if (err)
 224                return err;
 225
 226        err = pcim_iomap_regions(pdev, 0x0001, KBUILD_MODNAME);
 227        if (err)
 228                return err;
 229
 230        spin_lock_init(&chip->irq_lock);
 231        chip->pdev = pdev;
 232        chip->iobase = pcim_iomap_table(pdev)[0];
 233
 234        pci_set_drvdata(pdev, chip);
 235
 236        err = devm_request_irq(&pdev->dev, pdev->irq,
 237                cb710_irq_handler, IRQF_SHARED, KBUILD_MODNAME, chip);
 238        if (err)
 239                return err;
 240
 241        err = ida_alloc(&cb710_ida, GFP_KERNEL);
 242        if (err < 0)
 243                return err;
 244        chip->platform_id = err;
 245
 246        dev_info(&pdev->dev, "id %d, IO 0x%p, IRQ %d\n",
 247                chip->platform_id, chip->iobase, pdev->irq);
 248
 249        if (val & CB710_SLOT_MMC) {     /* MMC/SD slot */
 250                err = cb710_register_slot(chip,
 251                        CB710_SLOT_MMC, 0x00, "cb710-mmc");
 252                if (err)
 253                        return err;
 254        }
 255
 256        if (val & CB710_SLOT_MS) {      /* MemoryStick slot */
 257                err = cb710_register_slot(chip,
 258                        CB710_SLOT_MS, 0x40, "cb710-ms");
 259                if (err)
 260                        goto unreg_mmc;
 261        }
 262
 263        if (val & CB710_SLOT_SM) {      /* SmartMedia slot */
 264                err = cb710_register_slot(chip,
 265                        CB710_SLOT_SM, 0x60, "cb710-sm");
 266                if (err)
 267                        goto unreg_ms;
 268        }
 269
 270        return 0;
 271unreg_ms:
 272        cb710_unregister_slot(chip, CB710_SLOT_MS);
 273unreg_mmc:
 274        cb710_unregister_slot(chip, CB710_SLOT_MMC);
 275
 276#ifdef CONFIG_CB710_DEBUG_ASSUMPTIONS
 277        BUG_ON(atomic_read(&chip->slot_refs_count) != 0);
 278#endif
 279        return err;
 280}
 281
 282static void cb710_remove_one(struct pci_dev *pdev)
 283{
 284        struct cb710_chip *chip = pci_get_drvdata(pdev);
 285
 286        cb710_unregister_slot(chip, CB710_SLOT_SM);
 287        cb710_unregister_slot(chip, CB710_SLOT_MS);
 288        cb710_unregister_slot(chip, CB710_SLOT_MMC);
 289#ifdef CONFIG_CB710_DEBUG_ASSUMPTIONS
 290        BUG_ON(atomic_read(&chip->slot_refs_count) != 0);
 291#endif
 292
 293        ida_free(&cb710_ida, chip->platform_id);
 294}
 295
 296static const struct pci_device_id cb710_pci_tbl[] = {
 297        { PCI_VENDOR_ID_ENE, PCI_DEVICE_ID_ENE_CB710_FLASH,
 298                PCI_ANY_ID, PCI_ANY_ID, },
 299        { 0, }
 300};
 301
 302static SIMPLE_DEV_PM_OPS(cb710_pm_ops, cb710_suspend, cb710_resume);
 303
 304static struct pci_driver cb710_driver = {
 305        .name = KBUILD_MODNAME,
 306        .id_table = cb710_pci_tbl,
 307        .probe = cb710_probe,
 308        .remove = cb710_remove_one,
 309        .driver.pm = &cb710_pm_ops,
 310};
 311
 312static int __init cb710_init_module(void)
 313{
 314        return pci_register_driver(&cb710_driver);
 315}
 316
 317static void __exit cb710_cleanup_module(void)
 318{
 319        pci_unregister_driver(&cb710_driver);
 320        ida_destroy(&cb710_ida);
 321}
 322
 323module_init(cb710_init_module);
 324module_exit(cb710_cleanup_module);
 325
 326MODULE_AUTHOR("Michał Mirosław <mirq-linux@rere.qmqm.pl>");
 327MODULE_DESCRIPTION("ENE CB710 memory card reader driver");
 328MODULE_LICENSE("GPL");
 329MODULE_DEVICE_TABLE(pci, cb710_pci_tbl);
 330