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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 */
 43int (*ixp4xx_pci_read)(u32 addr, u32 cmd, u32* data);
 44
 45/*
 46 * Base address for PCI regsiter region
 47 */
 48unsigned 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 */
 57static DEFINE_RAW_SPINLOCK(ixp4xx_pci_lock);
 58
 59/*
 60 * Read from PCI config space
 61 */
 62static 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 */
 74static 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
 83static 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
 98int 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
125int 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
147int 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
169static 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 */
188static u32 bytemask[] = {
189	/*0*/	0,
190	/*1*/	0xff,
191	/*2*/	0xffff,
192	/*3*/	0,
193	/*4*/	0xffffffff,
194};
195
196static 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
207static 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
218static 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
231static 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
242static 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
265static 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
286struct pci_ops ixp4xx_ops = {
287	.read =  ixp4xx_pci_read_config,
288	.write = ixp4xx_pci_write_config,
289};
290
291/*
292 * PCI abort handler
293 */
294static 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
319static 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 */
327static 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
337static 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
345void __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
443int 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
483int dma_set_coherent_mask(struct device *dev, u64 mask)
484{
485	if (mask >= SZ_64M - 1)
486		return 0;
487
488	return -EIO;
489}
490
491EXPORT_SYMBOL(ixp4xx_pci_read);
492EXPORT_SYMBOL(ixp4xx_pci_write);
493EXPORT_SYMBOL(dma_set_coherent_mask);