xref: /openbmc/linux/drivers/misc/cb710/core.c (revision 1edd0337)
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 
15 static DEFINE_IDA(cb710_ida);
16 
17 void 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 }
26 EXPORT_SYMBOL_GPL(cb710_pci_update_config_reg);
27 
28 /* Some magic writes based on Windows driver init code */
29 static 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 
64 static 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 
84 static 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 
95 static 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 
138 static 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 
157 void 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 }
167 EXPORT_SYMBOL_GPL(cb710_set_irq_handler);
168 
169 static 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 
178 static 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 
187 static 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;
271 unreg_ms:
272 	cb710_unregister_slot(chip, CB710_SLOT_MS);
273 unreg_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 
282 static 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 
296 static 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 
302 static SIMPLE_DEV_PM_OPS(cb710_pm_ops, cb710_suspend, cb710_resume);
303 
304 static 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 
312 static int __init cb710_init_module(void)
313 {
314 	return pci_register_driver(&cb710_driver);
315 }
316 
317 static void __exit cb710_cleanup_module(void)
318 {
319 	pci_unregister_driver(&cb710_driver);
320 	ida_destroy(&cb710_ida);
321 }
322 
323 module_init(cb710_init_module);
324 module_exit(cb710_cleanup_module);
325 
326 MODULE_AUTHOR("Michał Mirosław <mirq-linux@rere.qmqm.pl>");
327 MODULE_DESCRIPTION("ENE CB710 memory card reader driver");
328 MODULE_LICENSE("GPL");
329 MODULE_DEVICE_TABLE(pci, cb710_pci_tbl);
330