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8ee9d857 OJ |
1 | /* |
2 | * Copyright (C) 2006-2007 PA Semi, Inc | |
3 | * | |
4 | * Common functions for DMA access on PA Semi PWRficient | |
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 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program; if not, write to the Free Software | |
17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
18 | */ | |
19 | ||
20 | #include <linux/init.h> | |
21 | #include <linux/module.h> | |
22 | #include <linux/pci.h> | |
23 | #include <linux/of.h> | |
24 | ||
25 | #include <asm/pasemi_dma.h> | |
26 | ||
27 | #define MAX_TXCH 64 | |
28 | #define MAX_RXCH 64 | |
29 | ||
30 | static struct pasdma_status *dma_status; | |
31 | ||
32 | static void __iomem *iob_regs; | |
33 | static void __iomem *mac_regs[6]; | |
34 | static void __iomem *dma_regs; | |
35 | ||
36 | static int base_hw_irq; | |
37 | ||
38 | static int num_txch, num_rxch; | |
39 | ||
40 | static struct pci_dev *dma_pdev; | |
41 | ||
42 | /* Bitmaps to handle allocation of channels */ | |
43 | ||
44 | static DECLARE_BITMAP(txch_free, MAX_TXCH); | |
45 | static DECLARE_BITMAP(rxch_free, MAX_RXCH); | |
46 | ||
47 | /* pasemi_read_iob_reg - read IOB register | |
48 | * @reg: Register to read (offset into PCI CFG space) | |
49 | */ | |
50 | unsigned int pasemi_read_iob_reg(unsigned int reg) | |
51 | { | |
52 | return in_le32(iob_regs+reg); | |
53 | } | |
54 | EXPORT_SYMBOL(pasemi_read_iob_reg); | |
55 | ||
56 | /* pasemi_write_iob_reg - write IOB register | |
57 | * @reg: Register to write to (offset into PCI CFG space) | |
58 | * @val: Value to write | |
59 | */ | |
60 | void pasemi_write_iob_reg(unsigned int reg, unsigned int val) | |
61 | { | |
62 | out_le32(iob_regs+reg, val); | |
63 | } | |
64 | EXPORT_SYMBOL(pasemi_write_iob_reg); | |
65 | ||
66 | /* pasemi_read_mac_reg - read MAC register | |
67 | * @intf: MAC interface | |
68 | * @reg: Register to read (offset into PCI CFG space) | |
69 | */ | |
70 | unsigned int pasemi_read_mac_reg(int intf, unsigned int reg) | |
71 | { | |
72 | return in_le32(mac_regs[intf]+reg); | |
73 | } | |
74 | EXPORT_SYMBOL(pasemi_read_mac_reg); | |
75 | ||
76 | /* pasemi_write_mac_reg - write MAC register | |
77 | * @intf: MAC interface | |
78 | * @reg: Register to write to (offset into PCI CFG space) | |
79 | * @val: Value to write | |
80 | */ | |
81 | void pasemi_write_mac_reg(int intf, unsigned int reg, unsigned int val) | |
82 | { | |
83 | out_le32(mac_regs[intf]+reg, val); | |
84 | } | |
85 | EXPORT_SYMBOL(pasemi_write_mac_reg); | |
86 | ||
87 | /* pasemi_read_dma_reg - read DMA register | |
88 | * @reg: Register to read (offset into PCI CFG space) | |
89 | */ | |
90 | unsigned int pasemi_read_dma_reg(unsigned int reg) | |
91 | { | |
92 | return in_le32(dma_regs+reg); | |
93 | } | |
94 | EXPORT_SYMBOL(pasemi_read_dma_reg); | |
95 | ||
96 | /* pasemi_write_dma_reg - write DMA register | |
97 | * @reg: Register to write to (offset into PCI CFG space) | |
98 | * @val: Value to write | |
99 | */ | |
100 | void pasemi_write_dma_reg(unsigned int reg, unsigned int val) | |
101 | { | |
102 | out_le32(dma_regs+reg, val); | |
103 | } | |
104 | EXPORT_SYMBOL(pasemi_write_dma_reg); | |
105 | ||
106 | static int pasemi_alloc_tx_chan(enum pasemi_dmachan_type type) | |
107 | { | |
108 | int bit; | |
109 | int start, limit; | |
110 | ||
111 | switch (type & (TXCHAN_EVT0|TXCHAN_EVT1)) { | |
112 | case TXCHAN_EVT0: | |
113 | start = 0; | |
114 | limit = 10; | |
115 | break; | |
116 | case TXCHAN_EVT1: | |
117 | start = 10; | |
118 | limit = MAX_TXCH; | |
119 | break; | |
120 | default: | |
121 | start = 0; | |
122 | limit = MAX_TXCH; | |
123 | break; | |
124 | } | |
125 | retry: | |
126 | bit = find_next_bit(txch_free, MAX_TXCH, start); | |
127 | if (bit >= limit) | |
128 | return -ENOSPC; | |
129 | if (!test_and_clear_bit(bit, txch_free)) | |
130 | goto retry; | |
131 | ||
132 | return bit; | |
133 | } | |
134 | ||
135 | static void pasemi_free_tx_chan(int chan) | |
136 | { | |
137 | BUG_ON(test_bit(chan, txch_free)); | |
138 | set_bit(chan, txch_free); | |
139 | } | |
140 | ||
141 | static int pasemi_alloc_rx_chan(void) | |
142 | { | |
143 | int bit; | |
144 | retry: | |
145 | bit = find_first_bit(rxch_free, MAX_RXCH); | |
146 | if (bit >= MAX_TXCH) | |
147 | return -ENOSPC; | |
148 | if (!test_and_clear_bit(bit, rxch_free)) | |
149 | goto retry; | |
150 | ||
151 | return bit; | |
152 | } | |
153 | ||
154 | static void pasemi_free_rx_chan(int chan) | |
155 | { | |
156 | BUG_ON(test_bit(chan, rxch_free)); | |
157 | set_bit(chan, rxch_free); | |
158 | } | |
159 | ||
160 | /* pasemi_dma_alloc_chan - Allocate a DMA channel | |
161 | * @type: Type of channel to allocate | |
162 | * @total_size: Total size of structure to allocate (to allow for more | |
163 | * room behind the structure to be used by the client) | |
164 | * @offset: Offset in bytes from start of the total structure to the beginning | |
165 | * of struct pasemi_dmachan. Needed when struct pasemi_dmachan is | |
166 | * not the first member of the client structure. | |
167 | * | |
168 | * pasemi_dma_alloc_chan allocates a DMA channel for use by a client. The | |
169 | * type argument specifies whether it's a RX or TX channel, and in the case | |
170 | * of TX channels which group it needs to belong to (if any). | |
171 | * | |
172 | * Returns a pointer to the total structure allocated on success, NULL | |
173 | * on failure. | |
174 | */ | |
175 | void *pasemi_dma_alloc_chan(enum pasemi_dmachan_type type, | |
176 | int total_size, int offset) | |
177 | { | |
178 | void *buf; | |
179 | struct pasemi_dmachan *chan; | |
180 | int chno; | |
181 | ||
182 | BUG_ON(total_size < sizeof(struct pasemi_dmachan)); | |
183 | ||
184 | buf = kzalloc(total_size, GFP_KERNEL); | |
185 | ||
186 | if (!buf) | |
187 | return NULL; | |
188 | chan = buf + offset; | |
189 | ||
190 | chan->priv = buf; | |
191 | ||
192 | switch (type & (TXCHAN|RXCHAN)) { | |
193 | case RXCHAN: | |
194 | chno = pasemi_alloc_rx_chan(); | |
195 | chan->chno = chno; | |
196 | chan->irq = irq_create_mapping(NULL, | |
197 | base_hw_irq + num_txch + chno); | |
198 | chan->status = &dma_status->rx_sta[chno]; | |
199 | break; | |
200 | case TXCHAN: | |
201 | chno = pasemi_alloc_tx_chan(type); | |
202 | chan->chno = chno; | |
203 | chan->irq = irq_create_mapping(NULL, base_hw_irq + chno); | |
204 | chan->status = &dma_status->tx_sta[chno]; | |
205 | break; | |
206 | } | |
207 | ||
208 | chan->chan_type = type; | |
209 | ||
210 | return chan; | |
211 | } | |
212 | EXPORT_SYMBOL(pasemi_dma_alloc_chan); | |
213 | ||
214 | /* pasemi_dma_free_chan - Free a previously allocated channel | |
215 | * @chan: Channel to free | |
216 | * | |
217 | * Frees a previously allocated channel. It will also deallocate any | |
218 | * descriptor ring associated with the channel, if allocated. | |
219 | */ | |
220 | void pasemi_dma_free_chan(struct pasemi_dmachan *chan) | |
221 | { | |
222 | if (chan->ring_virt) | |
223 | pasemi_dma_free_ring(chan); | |
224 | ||
225 | switch (chan->chan_type & (RXCHAN|TXCHAN)) { | |
226 | case RXCHAN: | |
227 | pasemi_free_rx_chan(chan->chno); | |
228 | break; | |
229 | case TXCHAN: | |
230 | pasemi_free_tx_chan(chan->chno); | |
231 | break; | |
232 | } | |
233 | ||
234 | kfree(chan->priv); | |
235 | } | |
236 | EXPORT_SYMBOL(pasemi_dma_free_chan); | |
237 | ||
238 | /* pasemi_dma_alloc_ring - Allocate descriptor ring for a channel | |
239 | * @chan: Channel for which to allocate | |
240 | * @ring_size: Ring size in 64-bit (8-byte) words | |
241 | * | |
242 | * Allocate a descriptor ring for a channel. Returns 0 on success, errno | |
243 | * on failure. The passed in struct pasemi_dmachan is updated with the | |
244 | * virtual and DMA addresses of the ring. | |
245 | */ | |
246 | int pasemi_dma_alloc_ring(struct pasemi_dmachan *chan, int ring_size) | |
247 | { | |
248 | BUG_ON(chan->ring_virt); | |
249 | ||
250 | chan->ring_size = ring_size; | |
251 | ||
252 | chan->ring_virt = dma_alloc_coherent(&dma_pdev->dev, | |
253 | ring_size * sizeof(u64), | |
254 | &chan->ring_dma, GFP_KERNEL); | |
255 | ||
256 | if (!chan->ring_virt) | |
257 | return -ENOMEM; | |
258 | ||
259 | memset(chan->ring_virt, 0, ring_size * sizeof(u64)); | |
260 | ||
261 | return 0; | |
262 | } | |
263 | EXPORT_SYMBOL(pasemi_dma_alloc_ring); | |
264 | ||
265 | /* pasemi_dma_free_ring - Free an allocated descriptor ring for a channel | |
266 | * @chan: Channel for which to free the descriptor ring | |
267 | * | |
268 | * Frees a previously allocated descriptor ring for a channel. | |
269 | */ | |
270 | void pasemi_dma_free_ring(struct pasemi_dmachan *chan) | |
271 | { | |
272 | BUG_ON(!chan->ring_virt); | |
273 | ||
274 | dma_free_coherent(&dma_pdev->dev, chan->ring_size * sizeof(u64), | |
275 | chan->ring_virt, chan->ring_dma); | |
276 | chan->ring_virt = NULL; | |
277 | chan->ring_size = 0; | |
278 | chan->ring_dma = 0; | |
279 | } | |
280 | EXPORT_SYMBOL(pasemi_dma_free_ring); | |
281 | ||
282 | /* pasemi_dma_start_chan - Start a DMA channel | |
283 | * @chan: Channel to start | |
284 | * @cmdsta: Additional CCMDSTA/TCMDSTA bits to write | |
285 | * | |
286 | * Enables (starts) a DMA channel with optional additional arguments. | |
287 | */ | |
288 | void pasemi_dma_start_chan(const struct pasemi_dmachan *chan, const u32 cmdsta) | |
289 | { | |
290 | if (chan->chan_type == RXCHAN) | |
291 | pasemi_write_dma_reg(PAS_DMA_RXCHAN_CCMDSTA(chan->chno), | |
292 | cmdsta | PAS_DMA_RXCHAN_CCMDSTA_EN); | |
293 | else | |
294 | pasemi_write_dma_reg(PAS_DMA_TXCHAN_TCMDSTA(chan->chno), | |
295 | cmdsta | PAS_DMA_TXCHAN_TCMDSTA_EN); | |
296 | } | |
297 | EXPORT_SYMBOL(pasemi_dma_start_chan); | |
298 | ||
299 | /* pasemi_dma_stop_chan - Stop a DMA channel | |
300 | * @chan: Channel to stop | |
301 | * | |
302 | * Stops (disables) a DMA channel. This is done by setting the ST bit in the | |
303 | * CMDSTA register and waiting on the ACT (active) bit to clear, then | |
304 | * finally disabling the whole channel. | |
305 | * | |
306 | * This function will only try for a short while for the channel to stop, if | |
307 | * it doesn't it will return failure. | |
308 | * | |
309 | * Returns 1 on success, 0 on failure. | |
310 | */ | |
311 | #define MAX_RETRIES 5000 | |
312 | int pasemi_dma_stop_chan(const struct pasemi_dmachan *chan) | |
313 | { | |
314 | int reg, retries; | |
315 | u32 sta; | |
316 | ||
317 | if (chan->chan_type == RXCHAN) { | |
318 | reg = PAS_DMA_RXCHAN_CCMDSTA(chan->chno); | |
319 | pasemi_write_dma_reg(reg, PAS_DMA_RXCHAN_CCMDSTA_ST); | |
320 | for (retries = 0; retries < MAX_RETRIES; retries++) { | |
321 | sta = pasemi_read_dma_reg(reg); | |
322 | if (!(sta & PAS_DMA_RXCHAN_CCMDSTA_ACT)) { | |
323 | pasemi_write_dma_reg(reg, 0); | |
324 | return 1; | |
325 | } | |
326 | cond_resched(); | |
327 | } | |
328 | } else { | |
329 | reg = PAS_DMA_TXCHAN_TCMDSTA(chan->chno); | |
330 | pasemi_write_dma_reg(reg, PAS_DMA_TXCHAN_TCMDSTA_ST); | |
331 | for (retries = 0; retries < MAX_RETRIES; retries++) { | |
332 | sta = pasemi_read_dma_reg(reg); | |
333 | if (!(sta & PAS_DMA_TXCHAN_TCMDSTA_ACT)) { | |
334 | pasemi_write_dma_reg(reg, 0); | |
335 | return 1; | |
336 | } | |
337 | cond_resched(); | |
338 | } | |
339 | } | |
340 | ||
341 | return 0; | |
342 | } | |
343 | EXPORT_SYMBOL(pasemi_dma_stop_chan); | |
344 | ||
345 | /* pasemi_dma_alloc_buf - Allocate a buffer to use for DMA | |
346 | * @chan: Channel to allocate for | |
347 | * @size: Size of buffer in bytes | |
348 | * @handle: DMA handle | |
349 | * | |
350 | * Allocate a buffer to be used by the DMA engine for read/write, | |
351 | * similar to dma_alloc_coherent(). | |
352 | * | |
353 | * Returns the virtual address of the buffer, or NULL in case of failure. | |
354 | */ | |
355 | void *pasemi_dma_alloc_buf(struct pasemi_dmachan *chan, int size, | |
356 | dma_addr_t *handle) | |
357 | { | |
358 | return dma_alloc_coherent(&dma_pdev->dev, size, handle, GFP_KERNEL); | |
359 | } | |
360 | EXPORT_SYMBOL(pasemi_dma_alloc_buf); | |
361 | ||
362 | /* pasemi_dma_free_buf - Free a buffer used for DMA | |
363 | * @chan: Channel the buffer was allocated for | |
364 | * @size: Size of buffer in bytes | |
365 | * @handle: DMA handle | |
366 | * | |
367 | * Frees a previously allocated buffer. | |
368 | */ | |
369 | void pasemi_dma_free_buf(struct pasemi_dmachan *chan, int size, | |
370 | dma_addr_t *handle) | |
371 | { | |
372 | dma_free_coherent(&dma_pdev->dev, size, handle, GFP_KERNEL); | |
373 | } | |
374 | EXPORT_SYMBOL(pasemi_dma_free_buf); | |
375 | ||
376 | static void *map_onedev(struct pci_dev *p, int index) | |
377 | { | |
378 | struct device_node *dn; | |
379 | void __iomem *ret; | |
380 | ||
381 | dn = pci_device_to_OF_node(p); | |
382 | if (!dn) | |
383 | goto fallback; | |
384 | ||
385 | ret = of_iomap(dn, index); | |
386 | if (!ret) | |
387 | goto fallback; | |
388 | ||
389 | return ret; | |
390 | fallback: | |
391 | /* This is hardcoded and ugly, but we have some firmware versions | |
392 | * that don't provide the register space in the device tree. Luckily | |
393 | * they are at well-known locations so we can just do the math here. | |
394 | */ | |
395 | return ioremap(0xe0000000 + (p->devfn << 12), 0x2000); | |
396 | } | |
397 | ||
398 | /* pasemi_dma_init - Initialize the PA Semi DMA library | |
399 | * | |
400 | * This function initializes the DMA library. It must be called before | |
401 | * any other function in the library. | |
402 | * | |
403 | * Returns 0 on success, errno on failure. | |
404 | */ | |
405 | int pasemi_dma_init(void) | |
406 | { | |
407 | static spinlock_t init_lock = SPIN_LOCK_UNLOCKED; | |
408 | struct pci_dev *iob_pdev; | |
409 | struct pci_dev *pdev; | |
410 | struct resource res; | |
411 | struct device_node *dn; | |
412 | int i, intf, err = 0; | |
413 | u32 tmp; | |
414 | ||
415 | if (!machine_is(pasemi)) | |
416 | return -ENODEV; | |
417 | ||
418 | spin_lock(&init_lock); | |
419 | ||
420 | /* Make sure we haven't already initialized */ | |
421 | if (dma_pdev) | |
422 | goto out; | |
423 | ||
424 | iob_pdev = pci_get_device(PCI_VENDOR_ID_PASEMI, 0xa001, NULL); | |
425 | if (!iob_pdev) { | |
426 | BUG(); | |
427 | printk(KERN_WARNING "Can't find I/O Bridge\n"); | |
428 | err = -ENODEV; | |
429 | goto out; | |
430 | } | |
431 | iob_regs = map_onedev(iob_pdev, 0); | |
432 | ||
433 | dma_pdev = pci_get_device(PCI_VENDOR_ID_PASEMI, 0xa007, NULL); | |
434 | if (!dma_pdev) { | |
435 | BUG(); | |
436 | printk(KERN_WARNING "Can't find DMA controller\n"); | |
437 | err = -ENODEV; | |
438 | goto out; | |
439 | } | |
440 | dma_regs = map_onedev(dma_pdev, 0); | |
441 | base_hw_irq = virq_to_hw(dma_pdev->irq); | |
442 | ||
443 | pci_read_config_dword(dma_pdev, PAS_DMA_CAP_TXCH, &tmp); | |
444 | num_txch = (tmp & PAS_DMA_CAP_TXCH_TCHN_M) >> PAS_DMA_CAP_TXCH_TCHN_S; | |
445 | ||
446 | pci_read_config_dword(dma_pdev, PAS_DMA_CAP_RXCH, &tmp); | |
447 | num_rxch = (tmp & PAS_DMA_CAP_RXCH_RCHN_M) >> PAS_DMA_CAP_RXCH_RCHN_S; | |
448 | ||
449 | intf = 0; | |
450 | for (pdev = pci_get_device(PCI_VENDOR_ID_PASEMI, 0xa006, NULL); | |
451 | pdev; | |
452 | pdev = pci_get_device(PCI_VENDOR_ID_PASEMI, 0xa006, pdev)) | |
453 | mac_regs[intf++] = map_onedev(pdev, 0); | |
454 | ||
455 | pci_dev_put(pdev); | |
456 | ||
457 | for (pdev = pci_get_device(PCI_VENDOR_ID_PASEMI, 0xa005, NULL); | |
458 | pdev; | |
459 | pdev = pci_get_device(PCI_VENDOR_ID_PASEMI, 0xa005, pdev)) | |
460 | mac_regs[intf++] = map_onedev(pdev, 0); | |
461 | ||
462 | pci_dev_put(pdev); | |
463 | ||
464 | dn = pci_device_to_OF_node(iob_pdev); | |
465 | if (dn) | |
466 | err = of_address_to_resource(dn, 1, &res); | |
467 | if (!dn || err) { | |
468 | /* Fallback for old firmware */ | |
469 | res.start = 0xfd800000; | |
470 | res.end = res.start + 0x1000; | |
471 | } | |
472 | dma_status = __ioremap(res.start, res.end-res.start, 0); | |
473 | pci_dev_put(iob_pdev); | |
474 | ||
475 | for (i = 0; i < MAX_TXCH; i++) | |
476 | __set_bit(i, txch_free); | |
477 | ||
478 | for (i = 0; i < MAX_RXCH; i++) | |
479 | __set_bit(i, rxch_free); | |
480 | ||
481 | printk(KERN_INFO "PA Semi PWRficient DMA library initialized " | |
482 | "(%d tx, %d rx channels)\n", num_txch, num_rxch); | |
483 | ||
484 | out: | |
485 | spin_unlock(&init_lock); | |
486 | return err; | |
487 | } |