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1 /*
2 * This program is free software; you can redistribute it and/or
3 * modify it under the terms of the GNU General Public License
4 * as published by the Free Software Foundation; either version 2
5 * of the License, or (at your option) any later version.
6 *
7 * This program is distributed in the hope that it will be useful,
8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10 * GNU General Public License for more details.
11 *
12 * You should have received a copy of the GNU General Public License
13 * along with this program; if not, see <http://www.gnu.org/licenses/>.
14 */
15
16 /**
17 * Both AR2315 and AR2316 chips have PCI interface unit, which supports DMA
18 * and interrupt. PCI interface supports MMIO access method, but does not
19 * seem to support I/O ports.
20 *
21 * Read/write operation in the region 0x80000000-0xBFFFFFFF causes
22 * a memory read/write command on the PCI bus. 30 LSBs of address on
23 * the bus are taken from memory read/write request and 2 MSBs are
24 * determined by PCI unit configuration.
25 *
26 * To work with the configuration space instead of memory is necessary set
27 * the CFG_SEL bit in the PCI_MISC_CONFIG register.
28 *
29 * Devices on the bus can perform DMA requests via chip BAR1. PCI host
30 * controller BARs are programmend as if an external device is programmed.
31 * Which means that during configuration, IDSEL pin of the chip should be
32 * asserted.
33 *
34 * We know (and support) only one board that uses the PCI interface -
35 * Fonera 2.0g (FON2202). It has a USB EHCI controller connected to the
36 * AR2315 PCI bus. IDSEL pin of USB controller is connected to AD[13] line
37 * and IDSEL pin of AR2315 is connected to AD[16] line.
38 */
39
40 #include <linux/types.h>
41 #include <linux/pci.h>
42 #include <linux/platform_device.h>
43 #include <linux/kernel.h>
44 #include <linux/init.h>
45 #include <linux/mm.h>
46 #include <linux/delay.h>
47 #include <linux/bitops.h>
48 #include <linux/irq.h>
49 #include <linux/irqdomain.h>
50 #include <linux/io.h>
51 #include <asm/paccess.h>
52
53 /*
54 * PCI Bus Interface Registers
55 */
56 #define AR2315_PCI_1MS_REG 0x0008
57
58 #define AR2315_PCI_1MS_MASK 0x3FFFF /* # of AHB clk cycles in 1ms */
59
60 #define AR2315_PCI_MISC_CONFIG 0x000c
61
62 #define AR2315_PCIMISC_TXD_EN 0x00000001 /* Enable TXD for fragments */
63 #define AR2315_PCIMISC_CFG_SEL 0x00000002 /* Mem or Config cycles */
64 #define AR2315_PCIMISC_GIG_MASK 0x0000000C /* bits 31-30 for pci req */
65 #define AR2315_PCIMISC_RST_MODE 0x00000030
66 #define AR2315_PCIRST_INPUT 0x00000000 /* 4:5=0 rst is input */
67 #define AR2315_PCIRST_LOW 0x00000010 /* 4:5=1 rst to GND */
68 #define AR2315_PCIRST_HIGH 0x00000020 /* 4:5=2 rst to VDD */
69 #define AR2315_PCIGRANT_EN 0x00000000 /* 6:7=0 early grant en */
70 #define AR2315_PCIGRANT_FRAME 0x00000040 /* 6:7=1 grant waits 4 frame */
71 #define AR2315_PCIGRANT_IDLE 0x00000080 /* 6:7=2 grant waits 4 idle */
72 #define AR2315_PCIGRANT_GAP 0x00000000 /* 6:7=2 grant waits 4 idle */
73 #define AR2315_PCICACHE_DIS 0x00001000 /* PCI external access cache
74 * disable */
75
76 #define AR2315_PCI_OUT_TSTAMP 0x0010
77
78 #define AR2315_PCI_UNCACHE_CFG 0x0014
79
80 #define AR2315_PCI_IN_EN 0x0100
81
82 #define AR2315_PCI_IN_EN0 0x01 /* Enable chain 0 */
83 #define AR2315_PCI_IN_EN1 0x02 /* Enable chain 1 */
84 #define AR2315_PCI_IN_EN2 0x04 /* Enable chain 2 */
85 #define AR2315_PCI_IN_EN3 0x08 /* Enable chain 3 */
86
87 #define AR2315_PCI_IN_DIS 0x0104
88
89 #define AR2315_PCI_IN_DIS0 0x01 /* Disable chain 0 */
90 #define AR2315_PCI_IN_DIS1 0x02 /* Disable chain 1 */
91 #define AR2315_PCI_IN_DIS2 0x04 /* Disable chain 2 */
92 #define AR2315_PCI_IN_DIS3 0x08 /* Disable chain 3 */
93
94 #define AR2315_PCI_IN_PTR 0x0200
95
96 #define AR2315_PCI_OUT_EN 0x0400
97
98 #define AR2315_PCI_OUT_EN0 0x01 /* Enable chain 0 */
99
100 #define AR2315_PCI_OUT_DIS 0x0404
101
102 #define AR2315_PCI_OUT_DIS0 0x01 /* Disable chain 0 */
103
104 #define AR2315_PCI_OUT_PTR 0x0408
105
106 /* PCI interrupt status (write one to clear) */
107 #define AR2315_PCI_ISR 0x0500
108
109 #define AR2315_PCI_INT_TX 0x00000001 /* Desc In Completed */
110 #define AR2315_PCI_INT_TXOK 0x00000002 /* Desc In OK */
111 #define AR2315_PCI_INT_TXERR 0x00000004 /* Desc In ERR */
112 #define AR2315_PCI_INT_TXEOL 0x00000008 /* Desc In End-of-List */
113 #define AR2315_PCI_INT_RX 0x00000010 /* Desc Out Completed */
114 #define AR2315_PCI_INT_RXOK 0x00000020 /* Desc Out OK */
115 #define AR2315_PCI_INT_RXERR 0x00000040 /* Desc Out ERR */
116 #define AR2315_PCI_INT_RXEOL 0x00000080 /* Desc Out EOL */
117 #define AR2315_PCI_INT_TXOOD 0x00000200 /* Desc In Out-of-Desc */
118 #define AR2315_PCI_INT_DESCMASK 0x0000FFFF /* Desc Mask */
119 #define AR2315_PCI_INT_EXT 0x02000000 /* Extern PCI INTA */
120 #define AR2315_PCI_INT_ABORT 0x04000000 /* PCI bus abort event */
121
122 /* PCI interrupt mask */
123 #define AR2315_PCI_IMR 0x0504
124
125 /* Global PCI interrupt enable */
126 #define AR2315_PCI_IER 0x0508
127
128 #define AR2315_PCI_IER_DISABLE 0x00 /* disable pci interrupts */
129 #define AR2315_PCI_IER_ENABLE 0x01 /* enable pci interrupts */
130
131 #define AR2315_PCI_HOST_IN_EN 0x0800
132 #define AR2315_PCI_HOST_IN_DIS 0x0804
133 #define AR2315_PCI_HOST_IN_PTR 0x0810
134 #define AR2315_PCI_HOST_OUT_EN 0x0900
135 #define AR2315_PCI_HOST_OUT_DIS 0x0904
136 #define AR2315_PCI_HOST_OUT_PTR 0x0908
137
138 /*
139 * PCI interrupts, which share IP5
140 * Keep ordered according to AR2315_PCI_INT_XXX bits
141 */
142 #define AR2315_PCI_IRQ_EXT 25
143 #define AR2315_PCI_IRQ_ABORT 26
144 #define AR2315_PCI_IRQ_COUNT 27
145
146 /* Arbitrary size of memory region to access the configuration space */
147 #define AR2315_PCI_CFG_SIZE 0x00100000
148
149 #define AR2315_PCI_HOST_SLOT 3
150 #define AR2315_PCI_HOST_DEVID ((0xff18 << 16) | PCI_VENDOR_ID_ATHEROS)
151
152 /*
153 * We need some arbitrary non-zero value to be programmed to the BAR1 register
154 * of PCI host controller to enable DMA. The same value should be used as the
155 * offset to calculate the physical address of DMA buffer for PCI devices.
156 */
157 #define AR2315_PCI_HOST_SDRAM_BASEADDR 0x20000000
158
159 /* ??? access BAR */
160 #define AR2315_PCI_HOST_MBAR0 0x10000000
161 /* RAM access BAR */
162 #define AR2315_PCI_HOST_MBAR1 AR2315_PCI_HOST_SDRAM_BASEADDR
163 /* ??? access BAR */
164 #define AR2315_PCI_HOST_MBAR2 0x30000000
165
166 struct ar2315_pci_ctrl {
167 void __iomem *cfg_mem;
168 void __iomem *mmr_mem;
169 unsigned irq;
170 unsigned irq_ext;
171 struct irq_domain *domain;
172 struct pci_controller pci_ctrl;
173 struct resource mem_res;
174 struct resource io_res;
175 };
176
177 static inline dma_addr_t ar2315_dev_offset(struct device *dev)
178 {
179 if (dev && dev_is_pci(dev))
180 return AR2315_PCI_HOST_SDRAM_BASEADDR;
181 return 0;
182 }
183
184 dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
185 {
186 return paddr + ar2315_dev_offset(dev);
187 }
188
189 phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dma_addr)
190 {
191 return dma_addr - ar2315_dev_offset(dev);
192 }
193
194 static inline struct ar2315_pci_ctrl *ar2315_pci_bus_to_apc(struct pci_bus *bus)
195 {
196 struct pci_controller *hose = bus->sysdata;
197
198 return container_of(hose, struct ar2315_pci_ctrl, pci_ctrl);
199 }
200
201 static inline u32 ar2315_pci_reg_read(struct ar2315_pci_ctrl *apc, u32 reg)
202 {
203 return __raw_readl(apc->mmr_mem + reg);
204 }
205
206 static inline void ar2315_pci_reg_write(struct ar2315_pci_ctrl *apc, u32 reg,
207 u32 val)
208 {
209 __raw_writel(val, apc->mmr_mem + reg);
210 }
211
212 static inline void ar2315_pci_reg_mask(struct ar2315_pci_ctrl *apc, u32 reg,
213 u32 mask, u32 val)
214 {
215 u32 ret = ar2315_pci_reg_read(apc, reg);
216
217 ret &= ~mask;
218 ret |= val;
219 ar2315_pci_reg_write(apc, reg, ret);
220 }
221
222 static int ar2315_pci_cfg_access(struct ar2315_pci_ctrl *apc, unsigned devfn,
223 int where, int size, u32 *ptr, bool write)
224 {
225 int func = PCI_FUNC(devfn);
226 int dev = PCI_SLOT(devfn);
227 u32 addr = (1 << (13 + dev)) | (func << 8) | (where & ~3);
228 u32 mask = 0xffffffff >> 8 * (4 - size);
229 u32 sh = (where & 3) * 8;
230 u32 value, isr;
231
232 /* Prevent access past the remapped area */
233 if (addr >= AR2315_PCI_CFG_SIZE || dev > 18)
234 return PCIBIOS_DEVICE_NOT_FOUND;
235
236 /* Clear pending errors */
237 ar2315_pci_reg_write(apc, AR2315_PCI_ISR, AR2315_PCI_INT_ABORT);
238 /* Select Configuration access */
239 ar2315_pci_reg_mask(apc, AR2315_PCI_MISC_CONFIG, 0,
240 AR2315_PCIMISC_CFG_SEL);
241
242 mb(); /* PCI must see space change before we begin */
243
244 value = __raw_readl(apc->cfg_mem + addr);
245
246 isr = ar2315_pci_reg_read(apc, AR2315_PCI_ISR);
247
248 if (isr & AR2315_PCI_INT_ABORT)
249 goto exit_err;
250
251 if (write) {
252 value = (value & ~(mask << sh)) | *ptr << sh;
253 __raw_writel(value, apc->cfg_mem + addr);
254 isr = ar2315_pci_reg_read(apc, AR2315_PCI_ISR);
255 if (isr & AR2315_PCI_INT_ABORT)
256 goto exit_err;
257 } else {
258 *ptr = (value >> sh) & mask;
259 }
260
261 goto exit;
262
263 exit_err:
264 ar2315_pci_reg_write(apc, AR2315_PCI_ISR, AR2315_PCI_INT_ABORT);
265 if (!write)
266 *ptr = 0xffffffff;
267
268 exit:
269 /* Select Memory access */
270 ar2315_pci_reg_mask(apc, AR2315_PCI_MISC_CONFIG, AR2315_PCIMISC_CFG_SEL,
271 0);
272
273 return isr & AR2315_PCI_INT_ABORT ? PCIBIOS_DEVICE_NOT_FOUND :
274 PCIBIOS_SUCCESSFUL;
275 }
276
277 static inline int ar2315_pci_local_cfg_rd(struct ar2315_pci_ctrl *apc,
278 unsigned devfn, int where, u32 *val)
279 {
280 return ar2315_pci_cfg_access(apc, devfn, where, sizeof(u32), val,
281 false);
282 }
283
284 static inline int ar2315_pci_local_cfg_wr(struct ar2315_pci_ctrl *apc,
285 unsigned devfn, int where, u32 val)
286 {
287 return ar2315_pci_cfg_access(apc, devfn, where, sizeof(u32), &val,
288 true);
289 }
290
291 static int ar2315_pci_cfg_read(struct pci_bus *bus, unsigned devfn, int where,
292 int size, u32 *value)
293 {
294 struct ar2315_pci_ctrl *apc = ar2315_pci_bus_to_apc(bus);
295
296 if (PCI_SLOT(devfn) == AR2315_PCI_HOST_SLOT)
297 return PCIBIOS_DEVICE_NOT_FOUND;
298
299 return ar2315_pci_cfg_access(apc, devfn, where, size, value, false);
300 }
301
302 static int ar2315_pci_cfg_write(struct pci_bus *bus, unsigned devfn, int where,
303 int size, u32 value)
304 {
305 struct ar2315_pci_ctrl *apc = ar2315_pci_bus_to_apc(bus);
306
307 if (PCI_SLOT(devfn) == AR2315_PCI_HOST_SLOT)
308 return PCIBIOS_DEVICE_NOT_FOUND;
309
310 return ar2315_pci_cfg_access(apc, devfn, where, size, &value, true);
311 }
312
313 static struct pci_ops ar2315_pci_ops = {
314 .read = ar2315_pci_cfg_read,
315 .write = ar2315_pci_cfg_write,
316 };
317
318 static int ar2315_pci_host_setup(struct ar2315_pci_ctrl *apc)
319 {
320 unsigned devfn = PCI_DEVFN(AR2315_PCI_HOST_SLOT, 0);
321 int res;
322 u32 id;
323
324 res = ar2315_pci_local_cfg_rd(apc, devfn, PCI_VENDOR_ID, &id);
325 if (res != PCIBIOS_SUCCESSFUL || id != AR2315_PCI_HOST_DEVID)
326 return -ENODEV;
327
328 /* Program MBARs */
329 ar2315_pci_local_cfg_wr(apc, devfn, PCI_BASE_ADDRESS_0,
330 AR2315_PCI_HOST_MBAR0);
331 ar2315_pci_local_cfg_wr(apc, devfn, PCI_BASE_ADDRESS_1,
332 AR2315_PCI_HOST_MBAR1);
333 ar2315_pci_local_cfg_wr(apc, devfn, PCI_BASE_ADDRESS_2,
334 AR2315_PCI_HOST_MBAR2);
335
336 /* Run */
337 ar2315_pci_local_cfg_wr(apc, devfn, PCI_COMMAND, PCI_COMMAND_MEMORY |
338 PCI_COMMAND_MASTER | PCI_COMMAND_SPECIAL |
339 PCI_COMMAND_INVALIDATE | PCI_COMMAND_PARITY |
340 PCI_COMMAND_SERR | PCI_COMMAND_FAST_BACK);
341
342 return 0;
343 }
344
345 static void ar2315_pci_irq_handler(struct irq_desc *desc)
346 {
347 struct ar2315_pci_ctrl *apc = irq_desc_get_handler_data(desc);
348 u32 pending = ar2315_pci_reg_read(apc, AR2315_PCI_ISR) &
349 ar2315_pci_reg_read(apc, AR2315_PCI_IMR);
350 unsigned pci_irq = 0;
351
352 if (pending)
353 pci_irq = irq_find_mapping(apc->domain, __ffs(pending));
354
355 if (pci_irq)
356 generic_handle_irq(pci_irq);
357 else
358 spurious_interrupt();
359 }
360
361 static void ar2315_pci_irq_mask(struct irq_data *d)
362 {
363 struct ar2315_pci_ctrl *apc = irq_data_get_irq_chip_data(d);
364
365 ar2315_pci_reg_mask(apc, AR2315_PCI_IMR, BIT(d->hwirq), 0);
366 }
367
368 static void ar2315_pci_irq_mask_ack(struct irq_data *d)
369 {
370 struct ar2315_pci_ctrl *apc = irq_data_get_irq_chip_data(d);
371 u32 m = BIT(d->hwirq);
372
373 ar2315_pci_reg_mask(apc, AR2315_PCI_IMR, m, 0);
374 ar2315_pci_reg_write(apc, AR2315_PCI_ISR, m);
375 }
376
377 static void ar2315_pci_irq_unmask(struct irq_data *d)
378 {
379 struct ar2315_pci_ctrl *apc = irq_data_get_irq_chip_data(d);
380
381 ar2315_pci_reg_mask(apc, AR2315_PCI_IMR, 0, BIT(d->hwirq));
382 }
383
384 static struct irq_chip ar2315_pci_irq_chip = {
385 .name = "AR2315-PCI",
386 .irq_mask = ar2315_pci_irq_mask,
387 .irq_mask_ack = ar2315_pci_irq_mask_ack,
388 .irq_unmask = ar2315_pci_irq_unmask,
389 };
390
391 static int ar2315_pci_irq_map(struct irq_domain *d, unsigned irq,
392 irq_hw_number_t hw)
393 {
394 irq_set_chip_and_handler(irq, &ar2315_pci_irq_chip, handle_level_irq);
395 irq_set_chip_data(irq, d->host_data);
396 return 0;
397 }
398
399 static struct irq_domain_ops ar2315_pci_irq_domain_ops = {
400 .map = ar2315_pci_irq_map,
401 };
402
403 static void ar2315_pci_irq_init(struct ar2315_pci_ctrl *apc)
404 {
405 ar2315_pci_reg_mask(apc, AR2315_PCI_IER, AR2315_PCI_IER_ENABLE, 0);
406 ar2315_pci_reg_mask(apc, AR2315_PCI_IMR, (AR2315_PCI_INT_ABORT |
407 AR2315_PCI_INT_EXT), 0);
408
409 apc->irq_ext = irq_create_mapping(apc->domain, AR2315_PCI_IRQ_EXT);
410
411 irq_set_chained_handler_and_data(apc->irq, ar2315_pci_irq_handler,
412 apc);
413
414 /* Clear any pending Abort or external Interrupts
415 * and enable interrupt processing */
416 ar2315_pci_reg_write(apc, AR2315_PCI_ISR, AR2315_PCI_INT_ABORT |
417 AR2315_PCI_INT_EXT);
418 ar2315_pci_reg_mask(apc, AR2315_PCI_IER, 0, AR2315_PCI_IER_ENABLE);
419 }
420
421 static int ar2315_pci_probe(struct platform_device *pdev)
422 {
423 struct ar2315_pci_ctrl *apc;
424 struct device *dev = &pdev->dev;
425 struct resource *res;
426 int irq, err;
427
428 apc = devm_kzalloc(dev, sizeof(*apc), GFP_KERNEL);
429 if (!apc)
430 return -ENOMEM;
431
432 irq = platform_get_irq(pdev, 0);
433 if (irq < 0)
434 return -EINVAL;
435 apc->irq = irq;
436
437 res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
438 "ar2315-pci-ctrl");
439 apc->mmr_mem = devm_ioremap_resource(dev, res);
440 if (IS_ERR(apc->mmr_mem))
441 return PTR_ERR(apc->mmr_mem);
442
443 res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
444 "ar2315-pci-ext");
445 if (!res)
446 return -EINVAL;
447
448 apc->mem_res.name = "AR2315 PCI mem space";
449 apc->mem_res.parent = res;
450 apc->mem_res.start = res->start;
451 apc->mem_res.end = res->end;
452 apc->mem_res.flags = IORESOURCE_MEM;
453
454 /* Remap PCI config space */
455 apc->cfg_mem = devm_ioremap_nocache(dev, res->start,
456 AR2315_PCI_CFG_SIZE);
457 if (!apc->cfg_mem) {
458 dev_err(dev, "failed to remap PCI config space\n");
459 return -ENOMEM;
460 }
461
462 /* Reset the PCI bus by setting bits 5-4 in PCI_MCFG */
463 ar2315_pci_reg_mask(apc, AR2315_PCI_MISC_CONFIG,
464 AR2315_PCIMISC_RST_MODE,
465 AR2315_PCIRST_LOW);
466 msleep(100);
467
468 /* Bring the PCI out of reset */
469 ar2315_pci_reg_mask(apc, AR2315_PCI_MISC_CONFIG,
470 AR2315_PCIMISC_RST_MODE,
471 AR2315_PCIRST_HIGH | AR2315_PCICACHE_DIS | 0x8);
472
473 ar2315_pci_reg_write(apc, AR2315_PCI_UNCACHE_CFG,
474 0x1E | /* 1GB uncached */
475 (1 << 5) | /* Enable uncached */
476 (0x2 << 30) /* Base: 0x80000000 */);
477 ar2315_pci_reg_read(apc, AR2315_PCI_UNCACHE_CFG);
478
479 msleep(500);
480
481 err = ar2315_pci_host_setup(apc);
482 if (err)
483 return err;
484
485 apc->domain = irq_domain_add_linear(NULL, AR2315_PCI_IRQ_COUNT,
486 &ar2315_pci_irq_domain_ops, apc);
487 if (!apc->domain) {
488 dev_err(dev, "failed to add IRQ domain\n");
489 return -ENOMEM;
490 }
491
492 ar2315_pci_irq_init(apc);
493
494 /* PCI controller does not support I/O ports */
495 apc->io_res.name = "AR2315 IO space";
496 apc->io_res.start = 0;
497 apc->io_res.end = 0;
498 apc->io_res.flags = IORESOURCE_IO,
499
500 apc->pci_ctrl.pci_ops = &ar2315_pci_ops;
501 apc->pci_ctrl.mem_resource = &apc->mem_res,
502 apc->pci_ctrl.io_resource = &apc->io_res,
503
504 register_pci_controller(&apc->pci_ctrl);
505
506 dev_info(dev, "register PCI controller\n");
507
508 return 0;
509 }
510
511 static struct platform_driver ar2315_pci_driver = {
512 .probe = ar2315_pci_probe,
513 .driver = {
514 .name = "ar2315-pci",
515 },
516 };
517
518 static int __init ar2315_pci_init(void)
519 {
520 return platform_driver_register(&ar2315_pci_driver);
521 }
522 arch_initcall(ar2315_pci_init);
523
524 int pcibios_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
525 {
526 struct ar2315_pci_ctrl *apc = ar2315_pci_bus_to_apc(dev->bus);
527
528 return slot ? 0 : apc->irq_ext;
529 }
530
531 int pcibios_plat_dev_init(struct pci_dev *dev)
532 {
533 return 0;
534 }