xref: /openbmc/linux/drivers/misc/cb710/core.c (revision 8fdff1dc)
1 /*
2  *  cb710/core.c
3  *
4  *  Copyright by Michał Mirosław, 2008-2009
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/pci.h>
13 #include <linux/spinlock.h>
14 #include <linux/idr.h>
15 #include <linux/cb710.h>
16 #include <linux/gfp.h>
17 
18 static DEFINE_IDA(cb710_ida);
19 static DEFINE_SPINLOCK(cb710_ida_lock);
20 
21 void cb710_pci_update_config_reg(struct pci_dev *pdev,
22 	int reg, uint32_t mask, uint32_t xor)
23 {
24 	u32 rval;
25 
26 	pci_read_config_dword(pdev, reg, &rval);
27 	rval = (rval & mask) ^ xor;
28 	pci_write_config_dword(pdev, reg, rval);
29 }
30 EXPORT_SYMBOL_GPL(cb710_pci_update_config_reg);
31 
32 /* Some magic writes based on Windows driver init code */
33 static int cb710_pci_configure(struct pci_dev *pdev)
34 {
35 	unsigned int devfn = PCI_DEVFN(PCI_SLOT(pdev->devfn), 0);
36 	struct pci_dev *pdev0;
37 	u32 val;
38 
39 	cb710_pci_update_config_reg(pdev, 0x48,
40 		~0x000000FF, 0x0000003F);
41 
42 	pci_read_config_dword(pdev, 0x48, &val);
43 	if (val & 0x80000000)
44 		return 0;
45 
46 	pdev0 = pci_get_slot(pdev->bus, devfn);
47 	if (!pdev0)
48 		return -ENODEV;
49 
50 	if (pdev0->vendor == PCI_VENDOR_ID_ENE
51 	    && pdev0->device == PCI_DEVICE_ID_ENE_720) {
52 		cb710_pci_update_config_reg(pdev0, 0x8C,
53 			~0x00F00000, 0x00100000);
54 		cb710_pci_update_config_reg(pdev0, 0xB0,
55 			~0x08000000, 0x08000000);
56 	}
57 
58 	cb710_pci_update_config_reg(pdev0, 0x8C,
59 		~0x00000F00, 0x00000200);
60 	cb710_pci_update_config_reg(pdev0, 0x90,
61 		~0x00060000, 0x00040000);
62 
63 	pci_dev_put(pdev0);
64 
65 	return 0;
66 }
67 
68 static irqreturn_t cb710_irq_handler(int irq, void *data)
69 {
70 	struct cb710_chip *chip = data;
71 	struct cb710_slot *slot = &chip->slot[0];
72 	irqreturn_t handled = IRQ_NONE;
73 	unsigned nr;
74 
75 	spin_lock(&chip->irq_lock); /* incl. smp_rmb() */
76 
77 	for (nr = chip->slots; nr; ++slot, --nr) {
78 		cb710_irq_handler_t handler_func = slot->irq_handler;
79 		if (handler_func && handler_func(slot))
80 			handled = IRQ_HANDLED;
81 	}
82 
83 	spin_unlock(&chip->irq_lock);
84 
85 	return handled;
86 }
87 
88 static void cb710_release_slot(struct device *dev)
89 {
90 #ifdef CONFIG_CB710_DEBUG_ASSUMPTIONS
91 	struct cb710_slot *slot = cb710_pdev_to_slot(to_platform_device(dev));
92 	struct cb710_chip *chip = cb710_slot_to_chip(slot);
93 
94 	/* slot struct can be freed now */
95 	atomic_dec(&chip->slot_refs_count);
96 #endif
97 }
98 
99 static int cb710_register_slot(struct cb710_chip *chip,
100 	unsigned slot_mask, unsigned io_offset, const char *name)
101 {
102 	int nr = chip->slots;
103 	struct cb710_slot *slot = &chip->slot[nr];
104 	int err;
105 
106 	dev_dbg(cb710_chip_dev(chip),
107 		"register: %s.%d; slot %d; mask %d; IO offset: 0x%02X\n",
108 		name, chip->platform_id, nr, slot_mask, io_offset);
109 
110 	/* slot->irq_handler == NULL here; this needs to be
111 	 * seen before platform_device_register() */
112 	++chip->slots;
113 	smp_wmb();
114 
115 	slot->iobase = chip->iobase + io_offset;
116 	slot->pdev.name = name;
117 	slot->pdev.id = chip->platform_id;
118 	slot->pdev.dev.parent = &chip->pdev->dev;
119 	slot->pdev.dev.release = cb710_release_slot;
120 
121 	err = platform_device_register(&slot->pdev);
122 
123 #ifdef CONFIG_CB710_DEBUG_ASSUMPTIONS
124 	atomic_inc(&chip->slot_refs_count);
125 #endif
126 
127 	if (err) {
128 		/* device_initialize() called from platform_device_register()
129 		 * wants this on error path */
130 		platform_device_put(&slot->pdev);
131 
132 		/* slot->irq_handler == NULL here anyway, so no lock needed */
133 		--chip->slots;
134 		return err;
135 	}
136 
137 	chip->slot_mask |= slot_mask;
138 
139 	return 0;
140 }
141 
142 static void cb710_unregister_slot(struct cb710_chip *chip,
143 	unsigned slot_mask)
144 {
145 	int nr = chip->slots - 1;
146 
147 	if (!(chip->slot_mask & slot_mask))
148 		return;
149 
150 	platform_device_unregister(&chip->slot[nr].pdev);
151 
152 	/* complementary to spin_unlock() in cb710_set_irq_handler() */
153 	smp_rmb();
154 	BUG_ON(chip->slot[nr].irq_handler != NULL);
155 
156 	/* slot->irq_handler == NULL here, so no lock needed */
157 	--chip->slots;
158 	chip->slot_mask &= ~slot_mask;
159 }
160 
161 void cb710_set_irq_handler(struct cb710_slot *slot,
162 	cb710_irq_handler_t handler)
163 {
164 	struct cb710_chip *chip = cb710_slot_to_chip(slot);
165 	unsigned long flags;
166 
167 	spin_lock_irqsave(&chip->irq_lock, flags);
168 	slot->irq_handler = handler;
169 	spin_unlock_irqrestore(&chip->irq_lock, flags);
170 }
171 EXPORT_SYMBOL_GPL(cb710_set_irq_handler);
172 
173 #ifdef CONFIG_PM
174 
175 static int cb710_suspend(struct pci_dev *pdev, pm_message_t state)
176 {
177 	struct cb710_chip *chip = pci_get_drvdata(pdev);
178 
179 	free_irq(pdev->irq, chip);
180 	pci_save_state(pdev);
181 	pci_disable_device(pdev);
182 	if (state.event & PM_EVENT_SLEEP)
183 		pci_set_power_state(pdev, PCI_D3hot);
184 	return 0;
185 }
186 
187 static int cb710_resume(struct pci_dev *pdev)
188 {
189 	struct cb710_chip *chip = pci_get_drvdata(pdev);
190 	int err;
191 
192 	pci_set_power_state(pdev, PCI_D0);
193 	pci_restore_state(pdev);
194 	err = pcim_enable_device(pdev);
195 	if (err)
196 		return err;
197 
198 	return devm_request_irq(&pdev->dev, pdev->irq,
199 		cb710_irq_handler, IRQF_SHARED, KBUILD_MODNAME, chip);
200 }
201 
202 #endif /* CONFIG_PM */
203 
204 static int cb710_probe(struct pci_dev *pdev,
205 	const struct pci_device_id *ent)
206 {
207 	struct cb710_chip *chip;
208 	unsigned long flags;
209 	u32 val;
210 	int err;
211 	int n = 0;
212 
213 	err = cb710_pci_configure(pdev);
214 	if (err)
215 		return err;
216 
217 	/* this is actually magic... */
218 	pci_read_config_dword(pdev, 0x48, &val);
219 	if (!(val & 0x80000000)) {
220 		pci_write_config_dword(pdev, 0x48, val|0x71000000);
221 		pci_read_config_dword(pdev, 0x48, &val);
222 	}
223 
224 	dev_dbg(&pdev->dev, "PCI config[0x48] = 0x%08X\n", val);
225 	if (!(val & 0x70000000))
226 		return -ENODEV;
227 	val = (val >> 28) & 7;
228 	if (val & CB710_SLOT_MMC)
229 		++n;
230 	if (val & CB710_SLOT_MS)
231 		++n;
232 	if (val & CB710_SLOT_SM)
233 		++n;
234 
235 	chip = devm_kzalloc(&pdev->dev,
236 		sizeof(*chip) + n * sizeof(*chip->slot), GFP_KERNEL);
237 	if (!chip)
238 		return -ENOMEM;
239 
240 	err = pcim_enable_device(pdev);
241 	if (err)
242 		return err;
243 
244 	err = pcim_iomap_regions(pdev, 0x0001, KBUILD_MODNAME);
245 	if (err)
246 		return err;
247 
248 	spin_lock_init(&chip->irq_lock);
249 	chip->pdev = pdev;
250 	chip->iobase = pcim_iomap_table(pdev)[0];
251 
252 	pci_set_drvdata(pdev, chip);
253 
254 	err = devm_request_irq(&pdev->dev, pdev->irq,
255 		cb710_irq_handler, IRQF_SHARED, KBUILD_MODNAME, chip);
256 	if (err)
257 		return err;
258 
259 	do {
260 		if (!ida_pre_get(&cb710_ida, GFP_KERNEL))
261 			return -ENOMEM;
262 
263 		spin_lock_irqsave(&cb710_ida_lock, flags);
264 		err = ida_get_new(&cb710_ida, &chip->platform_id);
265 		spin_unlock_irqrestore(&cb710_ida_lock, flags);
266 
267 		if (err && err != -EAGAIN)
268 			return err;
269 	} while (err);
270 
271 
272 	dev_info(&pdev->dev, "id %d, IO 0x%p, IRQ %d\n",
273 		chip->platform_id, chip->iobase, pdev->irq);
274 
275 	if (val & CB710_SLOT_MMC) {	/* MMC/SD slot */
276 		err = cb710_register_slot(chip,
277 			CB710_SLOT_MMC, 0x00, "cb710-mmc");
278 		if (err)
279 			return err;
280 	}
281 
282 	if (val & CB710_SLOT_MS) {	/* MemoryStick slot */
283 		err = cb710_register_slot(chip,
284 			CB710_SLOT_MS, 0x40, "cb710-ms");
285 		if (err)
286 			goto unreg_mmc;
287 	}
288 
289 	if (val & CB710_SLOT_SM) {	/* SmartMedia slot */
290 		err = cb710_register_slot(chip,
291 			CB710_SLOT_SM, 0x60, "cb710-sm");
292 		if (err)
293 			goto unreg_ms;
294 	}
295 
296 	return 0;
297 unreg_ms:
298 	cb710_unregister_slot(chip, CB710_SLOT_MS);
299 unreg_mmc:
300 	cb710_unregister_slot(chip, CB710_SLOT_MMC);
301 
302 #ifdef CONFIG_CB710_DEBUG_ASSUMPTIONS
303 	BUG_ON(atomic_read(&chip->slot_refs_count) != 0);
304 #endif
305 	return err;
306 }
307 
308 static void cb710_remove_one(struct pci_dev *pdev)
309 {
310 	struct cb710_chip *chip = pci_get_drvdata(pdev);
311 	unsigned long flags;
312 
313 	cb710_unregister_slot(chip, CB710_SLOT_SM);
314 	cb710_unregister_slot(chip, CB710_SLOT_MS);
315 	cb710_unregister_slot(chip, CB710_SLOT_MMC);
316 #ifdef CONFIG_CB710_DEBUG_ASSUMPTIONS
317 	BUG_ON(atomic_read(&chip->slot_refs_count) != 0);
318 #endif
319 
320 	spin_lock_irqsave(&cb710_ida_lock, flags);
321 	ida_remove(&cb710_ida, chip->platform_id);
322 	spin_unlock_irqrestore(&cb710_ida_lock, flags);
323 }
324 
325 static const struct pci_device_id cb710_pci_tbl[] = {
326 	{ PCI_VENDOR_ID_ENE, PCI_DEVICE_ID_ENE_CB710_FLASH,
327 		PCI_ANY_ID, PCI_ANY_ID, },
328 	{ 0, }
329 };
330 
331 static struct pci_driver cb710_driver = {
332 	.name = KBUILD_MODNAME,
333 	.id_table = cb710_pci_tbl,
334 	.probe = cb710_probe,
335 	.remove = cb710_remove_one,
336 #ifdef CONFIG_PM
337 	.suspend = cb710_suspend,
338 	.resume = cb710_resume,
339 #endif
340 };
341 
342 static int __init cb710_init_module(void)
343 {
344 	return pci_register_driver(&cb710_driver);
345 }
346 
347 static void __exit cb710_cleanup_module(void)
348 {
349 	pci_unregister_driver(&cb710_driver);
350 	ida_destroy(&cb710_ida);
351 }
352 
353 module_init(cb710_init_module);
354 module_exit(cb710_cleanup_module);
355 
356 MODULE_AUTHOR("Michał Mirosław <mirq-linux@rere.qmqm.pl>");
357 MODULE_DESCRIPTION("ENE CB710 memory card reader driver");
358 MODULE_LICENSE("GPL");
359 MODULE_DEVICE_TABLE(pci, cb710_pci_tbl);
360