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1 /*
2  * arch/arm/mach-ixp4xx/common-pci.c
3  *
4  * IXP4XX PCI routines for all platforms
5  *
6  * Maintainer: Deepak Saxena <dsaxena@plexity.net>
7  *
8  * Copyright (C) 2002 Intel Corporation.
9  * Copyright (C) 2003 Greg Ungerer <gerg@snapgear.com>
10  * Copyright (C) 2003-2004 MontaVista Software, Inc.
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License version 2 as
14  * published by the Free Software Foundation.
15  *
16  */
17 
18 #include <linux/sched.h>
19 #include <linux/kernel.h>
20 #include <linux/pci.h>
21 #include <linux/interrupt.h>
22 #include <linux/mm.h>
23 #include <linux/init.h>
24 #include <linux/ioport.h>
25 #include <linux/slab.h>
26 #include <linux/delay.h>
27 #include <linux/device.h>
28 #include <linux/io.h>
29 #include <linux/export.h>
30 #include <asm/dma-mapping.h>
31 
32 #include <asm/cputype.h>
33 #include <asm/irq.h>
34 #include <asm/sizes.h>
35 #include <asm/mach/pci.h>
36 #include <mach/hardware.h>
37 
38 
39 /*
40  * IXP4xx PCI read function is dependent on whether we are
41  * running A0 or B0 (AppleGate) silicon.
42  */
43 int (*ixp4xx_pci_read)(u32 addr, u32 cmd, u32* data);
44 
45 /*
46  * Base address for PCI regsiter region
47  */
48 unsigned long ixp4xx_pci_reg_base = 0;
49 
50 /*
51  * PCI cfg an I/O routines are done by programming a
52  * command/byte enable register, and then read/writing
53  * the data from a data regsiter. We need to ensure
54  * these transactions are atomic or we will end up
55  * with corrupt data on the bus or in a driver.
56  */
57 static DEFINE_RAW_SPINLOCK(ixp4xx_pci_lock);
58 
59 /*
60  * Read from PCI config space
61  */
crp_read(u32 ad_cbe,u32 * data)62 static void crp_read(u32 ad_cbe, u32 *data)
63 {
64 	unsigned long flags;
65 	raw_spin_lock_irqsave(&ixp4xx_pci_lock, flags);
66 	*PCI_CRP_AD_CBE = ad_cbe;
67 	*data = *PCI_CRP_RDATA;
68 	raw_spin_unlock_irqrestore(&ixp4xx_pci_lock, flags);
69 }
70 
71 /*
72  * Write to PCI config space
73  */
crp_write(u32 ad_cbe,u32 data)74 static void crp_write(u32 ad_cbe, u32 data)
75 {
76 	unsigned long flags;
77 	raw_spin_lock_irqsave(&ixp4xx_pci_lock, flags);
78 	*PCI_CRP_AD_CBE = CRP_AD_CBE_WRITE | ad_cbe;
79 	*PCI_CRP_WDATA = data;
80 	raw_spin_unlock_irqrestore(&ixp4xx_pci_lock, flags);
81 }
82 
check_master_abort(void)83 static inline int check_master_abort(void)
84 {
85 	/* check Master Abort bit after access */
86 	unsigned long isr = *PCI_ISR;
87 
88 	if (isr & PCI_ISR_PFE) {
89 		/* make sure the Master Abort bit is reset */
90 		*PCI_ISR = PCI_ISR_PFE;
91 		pr_debug("%s failed\n", __func__);
92 		return 1;
93 	}
94 
95 	return 0;
96 }
97 
ixp4xx_pci_read_errata(u32 addr,u32 cmd,u32 * data)98 int ixp4xx_pci_read_errata(u32 addr, u32 cmd, u32* data)
99 {
100 	unsigned long flags;
101 	int retval = 0;
102 	int i;
103 
104 	raw_spin_lock_irqsave(&ixp4xx_pci_lock, flags);
105 
106 	*PCI_NP_AD = addr;
107 
108 	/*
109 	 * PCI workaround  - only works if NP PCI space reads have
110 	 * no side effects!!! Read 8 times. last one will be good.
111 	 */
112 	for (i = 0; i < 8; i++) {
113 		*PCI_NP_CBE = cmd;
114 		*data = *PCI_NP_RDATA;
115 		*data = *PCI_NP_RDATA;
116 	}
117 
118 	if(check_master_abort())
119 		retval = 1;
120 
121 	raw_spin_unlock_irqrestore(&ixp4xx_pci_lock, flags);
122 	return retval;
123 }
124 
ixp4xx_pci_read_no_errata(u32 addr,u32 cmd,u32 * data)125 int ixp4xx_pci_read_no_errata(u32 addr, u32 cmd, u32* data)
126 {
127 	unsigned long flags;
128 	int retval = 0;
129 
130 	raw_spin_lock_irqsave(&ixp4xx_pci_lock, flags);
131 
132 	*PCI_NP_AD = addr;
133 
134 	/* set up and execute the read */
135 	*PCI_NP_CBE = cmd;
136 
137 	/* the result of the read is now in NP_RDATA */
138 	*data = *PCI_NP_RDATA;
139 
140 	if(check_master_abort())
141 		retval = 1;
142 
143 	raw_spin_unlock_irqrestore(&ixp4xx_pci_lock, flags);
144 	return retval;
145 }
146 
ixp4xx_pci_write(u32 addr,u32 cmd,u32 data)147 int ixp4xx_pci_write(u32 addr, u32 cmd, u32 data)
148 {
149 	unsigned long flags;
150 	int retval = 0;
151 
152 	raw_spin_lock_irqsave(&ixp4xx_pci_lock, flags);
153 
154 	*PCI_NP_AD = addr;
155 
156 	/* set up the write */
157 	*PCI_NP_CBE = cmd;
158 
159 	/* execute the write by writing to NP_WDATA */
160 	*PCI_NP_WDATA = data;
161 
162 	if(check_master_abort())
163 		retval = 1;
164 
165 	raw_spin_unlock_irqrestore(&ixp4xx_pci_lock, flags);
166 	return retval;
167 }
168 
ixp4xx_config_addr(u8 bus_num,u16 devfn,int where)169 static u32 ixp4xx_config_addr(u8 bus_num, u16 devfn, int where)
170 {
171 	u32 addr;
172 	if (!bus_num) {
173 		/* type 0 */
174 		addr = BIT(32-PCI_SLOT(devfn)) | ((PCI_FUNC(devfn)) << 8) |
175 		    (where & ~3);
176 	} else {
177 		/* type 1 */
178 		addr = (bus_num << 16) | ((PCI_SLOT(devfn)) << 11) |
179 			((PCI_FUNC(devfn)) << 8) | (where & ~3) | 1;
180 	}
181 	return addr;
182 }
183 
184 /*
185  * Mask table, bits to mask for quantity of size 1, 2 or 4 bytes.
186  * 0 and 3 are not valid indexes...
187  */
188 static u32 bytemask[] = {
189 	/*0*/	0,
190 	/*1*/	0xff,
191 	/*2*/	0xffff,
192 	/*3*/	0,
193 	/*4*/	0xffffffff,
194 };
195 
local_byte_lane_enable_bits(u32 n,int size)196 static u32 local_byte_lane_enable_bits(u32 n, int size)
197 {
198 	if (size == 1)
199 		return (0xf & ~BIT(n)) << CRP_AD_CBE_BESL;
200 	if (size == 2)
201 		return (0xf & ~(BIT(n) | BIT(n+1))) << CRP_AD_CBE_BESL;
202 	if (size == 4)
203 		return 0;
204 	return 0xffffffff;
205 }
206 
local_read_config(int where,int size,u32 * value)207 static int local_read_config(int where, int size, u32 *value)
208 {
209 	u32 n, data;
210 	pr_debug("local_read_config from %d size %d\n", where, size);
211 	n = where % 4;
212 	crp_read(where & ~3, &data);
213 	*value = (data >> (8*n)) & bytemask[size];
214 	pr_debug("local_read_config read %#x\n", *value);
215 	return PCIBIOS_SUCCESSFUL;
216 }
217 
local_write_config(int where,int size,u32 value)218 static int local_write_config(int where, int size, u32 value)
219 {
220 	u32 n, byte_enables, data;
221 	pr_debug("local_write_config %#x to %d size %d\n", value, where, size);
222 	n = where % 4;
223 	byte_enables = local_byte_lane_enable_bits(n, size);
224 	if (byte_enables == 0xffffffff)
225 		return PCIBIOS_BAD_REGISTER_NUMBER;
226 	data = value << (8*n);
227 	crp_write((where & ~3) | byte_enables, data);
228 	return PCIBIOS_SUCCESSFUL;
229 }
230 
byte_lane_enable_bits(u32 n,int size)231 static u32 byte_lane_enable_bits(u32 n, int size)
232 {
233 	if (size == 1)
234 		return (0xf & ~BIT(n)) << 4;
235 	if (size == 2)
236 		return (0xf & ~(BIT(n) | BIT(n+1))) << 4;
237 	if (size == 4)
238 		return 0;
239 	return 0xffffffff;
240 }
241 
ixp4xx_pci_read_config(struct pci_bus * bus,unsigned int devfn,int where,int size,u32 * value)242 static int ixp4xx_pci_read_config(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *value)
243 {
244 	u32 n, byte_enables, addr, data;
245 	u8 bus_num = bus->number;
246 
247 	pr_debug("read_config from %d size %d dev %d:%d:%d\n", where, size,
248 		bus_num, PCI_SLOT(devfn), PCI_FUNC(devfn));
249 
250 	*value = 0xffffffff;
251 	n = where % 4;
252 	byte_enables = byte_lane_enable_bits(n, size);
253 	if (byte_enables == 0xffffffff)
254 		return PCIBIOS_BAD_REGISTER_NUMBER;
255 
256 	addr = ixp4xx_config_addr(bus_num, devfn, where);
257 	if (ixp4xx_pci_read(addr, byte_enables | NP_CMD_CONFIGREAD, &data))
258 		return PCIBIOS_DEVICE_NOT_FOUND;
259 
260 	*value = (data >> (8*n)) & bytemask[size];
261 	pr_debug("read_config_byte read %#x\n", *value);
262 	return PCIBIOS_SUCCESSFUL;
263 }
264 
ixp4xx_pci_write_config(struct pci_bus * bus,unsigned int devfn,int where,int size,u32 value)265 static int ixp4xx_pci_write_config(struct pci_bus *bus,  unsigned int devfn, int where, int size, u32 value)
266 {
267 	u32 n, byte_enables, addr, data;
268 	u8 bus_num = bus->number;
269 
270 	pr_debug("write_config_byte %#x to %d size %d dev %d:%d:%d\n", value, where,
271 		size, bus_num, PCI_SLOT(devfn), PCI_FUNC(devfn));
272 
273 	n = where % 4;
274 	byte_enables = byte_lane_enable_bits(n, size);
275 	if (byte_enables == 0xffffffff)
276 		return PCIBIOS_BAD_REGISTER_NUMBER;
277 
278 	addr = ixp4xx_config_addr(bus_num, devfn, where);
279 	data = value << (8*n);
280 	if (ixp4xx_pci_write(addr, byte_enables | NP_CMD_CONFIGWRITE, data))
281 		return PCIBIOS_DEVICE_NOT_FOUND;
282 
283 	return PCIBIOS_SUCCESSFUL;
284 }
285 
286 struct pci_ops ixp4xx_ops = {
287 	.read =  ixp4xx_pci_read_config,
288 	.write = ixp4xx_pci_write_config,
289 };
290 
291 /*
292  * PCI abort handler
293  */
abort_handler(unsigned long addr,unsigned int fsr,struct pt_regs * regs)294 static int abort_handler(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
295 {
296 	u32 isr, status;
297 
298 	isr = *PCI_ISR;
299 	local_read_config(PCI_STATUS, 2, &status);
300 	pr_debug("PCI: abort_handler addr = %#lx, isr = %#x, "
301 		"status = %#x\n", addr, isr, status);
302 
303 	/* make sure the Master Abort bit is reset */
304 	*PCI_ISR = PCI_ISR_PFE;
305 	status |= PCI_STATUS_REC_MASTER_ABORT;
306 	local_write_config(PCI_STATUS, 2, status);
307 
308 	/*
309 	 * If it was an imprecise abort, then we need to correct the
310 	 * return address to be _after_ the instruction.
311 	 */
312 	if (fsr & (1 << 10))
313 		regs->ARM_pc += 4;
314 
315 	return 0;
316 }
317 
318 
ixp4xx_needs_bounce(struct device * dev,dma_addr_t dma_addr,size_t size)319 static int ixp4xx_needs_bounce(struct device *dev, dma_addr_t dma_addr, size_t size)
320 {
321 	return (dma_addr + size) >= SZ_64M;
322 }
323 
324 /*
325  * Setup DMA mask to 64MB on PCI devices. Ignore all other devices.
326  */
ixp4xx_pci_platform_notify(struct device * dev)327 static int ixp4xx_pci_platform_notify(struct device *dev)
328 {
329 	if(dev->bus == &pci_bus_type) {
330 		*dev->dma_mask =  SZ_64M - 1;
331 		dev->coherent_dma_mask = SZ_64M - 1;
332 		dmabounce_register_dev(dev, 2048, 4096, ixp4xx_needs_bounce);
333 	}
334 	return 0;
335 }
336 
ixp4xx_pci_platform_notify_remove(struct device * dev)337 static int ixp4xx_pci_platform_notify_remove(struct device *dev)
338 {
339 	if(dev->bus == &pci_bus_type) {
340 		dmabounce_unregister_dev(dev);
341 	}
342 	return 0;
343 }
344 
ixp4xx_pci_preinit(void)345 void __init ixp4xx_pci_preinit(void)
346 {
347 	unsigned long cpuid = read_cpuid_id();
348 
349 #ifdef CONFIG_IXP4XX_INDIRECT_PCI
350 	pcibios_min_mem = 0x10000000; /* 1 GB of indirect PCI MMIO space */
351 #else
352 	pcibios_min_mem = 0x48000000; /* 64 MB of PCI MMIO space */
353 #endif
354 	/*
355 	 * Determine which PCI read method to use.
356 	 * Rev 0 IXP425 requires workaround.
357 	 */
358 	if (!(cpuid & 0xf) && cpu_is_ixp42x()) {
359 		printk("PCI: IXP42x A0 silicon detected - "
360 			"PCI Non-Prefetch Workaround Enabled\n");
361 		ixp4xx_pci_read = ixp4xx_pci_read_errata;
362 	} else
363 		ixp4xx_pci_read = ixp4xx_pci_read_no_errata;
364 
365 
366 	/* hook in our fault handler for PCI errors */
367 	hook_fault_code(16+6, abort_handler, SIGBUS, 0,
368 			"imprecise external abort");
369 
370 	pr_debug("setup PCI-AHB(inbound) and AHB-PCI(outbound) address mappings\n");
371 
372 	/*
373 	 * We use identity AHB->PCI address translation
374 	 * in the 0x48000000 to 0x4bffffff address space
375 	 */
376 	*PCI_PCIMEMBASE = 0x48494A4B;
377 
378 	/*
379 	 * We also use identity PCI->AHB address translation
380 	 * in 4 16MB BARs that begin at the physical memory start
381 	 */
382 	*PCI_AHBMEMBASE = (PHYS_OFFSET & 0xFF000000) +
383 		((PHYS_OFFSET & 0xFF000000) >> 8) +
384 		((PHYS_OFFSET & 0xFF000000) >> 16) +
385 		((PHYS_OFFSET & 0xFF000000) >> 24) +
386 		0x00010203;
387 
388 	if (*PCI_CSR & PCI_CSR_HOST) {
389 		printk("PCI: IXP4xx is host\n");
390 
391 		pr_debug("setup BARs in controller\n");
392 
393 		/*
394 		 * We configure the PCI inbound memory windows to be
395 		 * 1:1 mapped to SDRAM
396 		 */
397 		local_write_config(PCI_BASE_ADDRESS_0, 4, PHYS_OFFSET);
398 		local_write_config(PCI_BASE_ADDRESS_1, 4, PHYS_OFFSET + SZ_16M);
399 		local_write_config(PCI_BASE_ADDRESS_2, 4, PHYS_OFFSET + SZ_32M);
400 		local_write_config(PCI_BASE_ADDRESS_3, 4,
401 					PHYS_OFFSET + SZ_32M + SZ_16M);
402 
403 		/*
404 		 * Enable CSR window at 64 MiB to allow PCI masters
405 		 * to continue prefetching past 64 MiB boundary.
406 		 */
407 		local_write_config(PCI_BASE_ADDRESS_4, 4, PHYS_OFFSET + SZ_64M);
408 
409 		/*
410 		 * Enable the IO window to be way up high, at 0xfffffc00
411 		 */
412 		local_write_config(PCI_BASE_ADDRESS_5, 4, 0xfffffc01);
413 	} else {
414 		printk("PCI: IXP4xx is target - No bus scan performed\n");
415 	}
416 
417 	printk("PCI: IXP4xx Using %s access for memory space\n",
418 #ifndef CONFIG_IXP4XX_INDIRECT_PCI
419 			"direct"
420 #else
421 			"indirect"
422 #endif
423 		);
424 
425 	pr_debug("clear error bits in ISR\n");
426 	*PCI_ISR = PCI_ISR_PSE | PCI_ISR_PFE | PCI_ISR_PPE | PCI_ISR_AHBE;
427 
428 	/*
429 	 * Set Initialize Complete in PCI Control Register: allow IXP4XX to
430 	 * respond to PCI configuration cycles. Specify that the AHB bus is
431 	 * operating in big endian mode. Set up byte lane swapping between
432 	 * little-endian PCI and the big-endian AHB bus
433 	 */
434 #ifdef __ARMEB__
435 	*PCI_CSR = PCI_CSR_IC | PCI_CSR_ABE | PCI_CSR_PDS | PCI_CSR_ADS;
436 #else
437 	*PCI_CSR = PCI_CSR_IC | PCI_CSR_ABE;
438 #endif
439 
440 	pr_debug("DONE\n");
441 }
442 
ixp4xx_setup(int nr,struct pci_sys_data * sys)443 int ixp4xx_setup(int nr, struct pci_sys_data *sys)
444 {
445 	struct resource *res;
446 
447 	if (nr >= 1)
448 		return 0;
449 
450 	res = kzalloc(sizeof(*res) * 2, GFP_KERNEL);
451 	if (res == NULL) {
452 		/*
453 		 * If we're out of memory this early, something is wrong,
454 		 * so we might as well catch it here.
455 		 */
456 		panic("PCI: unable to allocate resources?\n");
457 	}
458 
459 	local_write_config(PCI_COMMAND, 2, PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY);
460 
461 	res[0].name = "PCI I/O Space";
462 	res[0].start = 0x00000000;
463 	res[0].end = 0x0000ffff;
464 	res[0].flags = IORESOURCE_IO;
465 
466 	res[1].name = "PCI Memory Space";
467 	res[1].start = PCIBIOS_MIN_MEM;
468 	res[1].end = PCIBIOS_MAX_MEM;
469 	res[1].flags = IORESOURCE_MEM;
470 
471 	request_resource(&ioport_resource, &res[0]);
472 	request_resource(&iomem_resource, &res[1]);
473 
474 	pci_add_resource_offset(&sys->resources, &res[0], sys->io_offset);
475 	pci_add_resource_offset(&sys->resources, &res[1], sys->mem_offset);
476 
477 	platform_notify = ixp4xx_pci_platform_notify;
478 	platform_notify_remove = ixp4xx_pci_platform_notify_remove;
479 
480 	return 1;
481 }
482 
ixp4xx_scan_bus(int nr,struct pci_sys_data * sys)483 struct pci_bus * __devinit ixp4xx_scan_bus(int nr, struct pci_sys_data *sys)
484 {
485 	return pci_scan_root_bus(NULL, sys->busnr, &ixp4xx_ops, sys,
486 				 &sys->resources);
487 }
488 
dma_set_coherent_mask(struct device * dev,u64 mask)489 int dma_set_coherent_mask(struct device *dev, u64 mask)
490 {
491 	if (mask >= SZ_64M - 1)
492 		return 0;
493 
494 	return -EIO;
495 }
496 
497 EXPORT_SYMBOL(ixp4xx_pci_read);
498 EXPORT_SYMBOL(ixp4xx_pci_write);
499 EXPORT_SYMBOL(dma_set_coherent_mask);
500