1 /*
2  *  linux/arch/arm/kernel/dec21285.c: PCI functions for DC21285
3  *
4  *  Copyright (C) 1998-2001 Russell King
5  *  Copyright (C) 1998-2000 Phil Blundell
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 #include <linux/kernel.h>
12 #include <linux/pci.h>
13 #include <linux/interrupt.h>
14 #include <linux/mm.h>
15 #include <linux/slab.h>
16 #include <linux/init.h>
17 #include <linux/ioport.h>
18 #include <linux/irq.h>
19 #include <linux/io.h>
20 #include <linux/spinlock.h>
21 
22 #include <asm/irq.h>
23 #include <asm/system.h>
24 #include <asm/mach/pci.h>
25 #include <asm/hardware/dec21285.h>
26 
27 #define MAX_SLOTS		21
28 
29 #define PCICMD_ABORT		((PCI_STATUS_REC_MASTER_ABORT| \
30 				  PCI_STATUS_REC_TARGET_ABORT)<<16)
31 
32 #define PCICMD_ERROR_BITS	((PCI_STATUS_DETECTED_PARITY | \
33 				  PCI_STATUS_REC_MASTER_ABORT | \
34 				  PCI_STATUS_REC_TARGET_ABORT | \
35 				  PCI_STATUS_PARITY) << 16)
36 
37 extern int setup_arm_irq(int, struct irqaction *);
38 extern void pcibios_report_status(u_int status_mask, int warn);
39 
40 static unsigned long
dc21285_base_address(struct pci_bus * bus,unsigned int devfn)41 dc21285_base_address(struct pci_bus *bus, unsigned int devfn)
42 {
43 	unsigned long addr = 0;
44 
45 	if (bus->number == 0) {
46 		if (PCI_SLOT(devfn) == 0)
47 			/*
48 			 * For devfn 0, point at the 21285
49 			 */
50 			addr = ARMCSR_BASE;
51 		else {
52 			devfn -= 1 << 3;
53 
54 			if (devfn < PCI_DEVFN(MAX_SLOTS, 0))
55 				addr = PCICFG0_BASE | 0xc00000 | (devfn << 8);
56 		}
57 	} else
58 		addr = PCICFG1_BASE | (bus->number << 16) | (devfn << 8);
59 
60 	return addr;
61 }
62 
63 static int
dc21285_read_config(struct pci_bus * bus,unsigned int devfn,int where,int size,u32 * value)64 dc21285_read_config(struct pci_bus *bus, unsigned int devfn, int where,
65 		    int size, u32 *value)
66 {
67 	unsigned long addr = dc21285_base_address(bus, devfn);
68 	u32 v = 0xffffffff;
69 
70 	if (addr)
71 		switch (size) {
72 		case 1:
73 			asm("ldrb	%0, [%1, %2]"
74 				: "=r" (v) : "r" (addr), "r" (where) : "cc");
75 			break;
76 		case 2:
77 			asm("ldrh	%0, [%1, %2]"
78 				: "=r" (v) : "r" (addr), "r" (where) : "cc");
79 			break;
80 		case 4:
81 			asm("ldr	%0, [%1, %2]"
82 				: "=r" (v) : "r" (addr), "r" (where) : "cc");
83 			break;
84 		}
85 
86 	*value = v;
87 
88 	v = *CSR_PCICMD;
89 	if (v & PCICMD_ABORT) {
90 		*CSR_PCICMD = v & (0xffff|PCICMD_ABORT);
91 		return -1;
92 	}
93 
94 	return PCIBIOS_SUCCESSFUL;
95 }
96 
97 static int
dc21285_write_config(struct pci_bus * bus,unsigned int devfn,int where,int size,u32 value)98 dc21285_write_config(struct pci_bus *bus, unsigned int devfn, int where,
99 		     int size, u32 value)
100 {
101 	unsigned long addr = dc21285_base_address(bus, devfn);
102 	u32 v;
103 
104 	if (addr)
105 		switch (size) {
106 		case 1:
107 			asm("strb	%0, [%1, %2]"
108 				: : "r" (value), "r" (addr), "r" (where)
109 				: "cc");
110 			break;
111 		case 2:
112 			asm("strh	%0, [%1, %2]"
113 				: : "r" (value), "r" (addr), "r" (where)
114 				: "cc");
115 			break;
116 		case 4:
117 			asm("str	%0, [%1, %2]"
118 				: : "r" (value), "r" (addr), "r" (where)
119 				: "cc");
120 			break;
121 		}
122 
123 	v = *CSR_PCICMD;
124 	if (v & PCICMD_ABORT) {
125 		*CSR_PCICMD = v & (0xffff|PCICMD_ABORT);
126 		return -1;
127 	}
128 
129 	return PCIBIOS_SUCCESSFUL;
130 }
131 
132 static struct pci_ops dc21285_ops = {
133 	.read	= dc21285_read_config,
134 	.write	= dc21285_write_config,
135 };
136 
137 static struct timer_list serr_timer;
138 static struct timer_list perr_timer;
139 
dc21285_enable_error(unsigned long __data)140 static void dc21285_enable_error(unsigned long __data)
141 {
142 	switch (__data) {
143 	case IRQ_PCI_SERR:
144 		del_timer(&serr_timer);
145 		break;
146 
147 	case IRQ_PCI_PERR:
148 		del_timer(&perr_timer);
149 		break;
150 	}
151 
152 	enable_irq(__data);
153 }
154 
155 /*
156  * Warn on PCI errors.
157  */
dc21285_abort_irq(int irq,void * dev_id)158 static irqreturn_t dc21285_abort_irq(int irq, void *dev_id)
159 {
160 	unsigned int cmd;
161 	unsigned int status;
162 
163 	cmd = *CSR_PCICMD;
164 	status = cmd >> 16;
165 	cmd = cmd & 0xffff;
166 
167 	if (status & PCI_STATUS_REC_MASTER_ABORT) {
168 		printk(KERN_DEBUG "PCI: master abort, pc=0x%08lx\n",
169 			instruction_pointer(get_irq_regs()));
170 		cmd |= PCI_STATUS_REC_MASTER_ABORT << 16;
171 	}
172 
173 	if (status & PCI_STATUS_REC_TARGET_ABORT) {
174 		printk(KERN_DEBUG "PCI: target abort: ");
175 		pcibios_report_status(PCI_STATUS_REC_MASTER_ABORT |
176 				      PCI_STATUS_SIG_TARGET_ABORT |
177 				      PCI_STATUS_REC_TARGET_ABORT, 1);
178 		printk("\n");
179 
180 		cmd |= PCI_STATUS_REC_TARGET_ABORT << 16;
181 	}
182 
183 	*CSR_PCICMD = cmd;
184 
185 	return IRQ_HANDLED;
186 }
187 
dc21285_serr_irq(int irq,void * dev_id)188 static irqreturn_t dc21285_serr_irq(int irq, void *dev_id)
189 {
190 	struct timer_list *timer = dev_id;
191 	unsigned int cntl;
192 
193 	printk(KERN_DEBUG "PCI: system error received: ");
194 	pcibios_report_status(PCI_STATUS_SIG_SYSTEM_ERROR, 1);
195 	printk("\n");
196 
197 	cntl = *CSR_SA110_CNTL & 0xffffdf07;
198 	*CSR_SA110_CNTL = cntl | SA110_CNTL_RXSERR;
199 
200 	/*
201 	 * back off this interrupt
202 	 */
203 	disable_irq(irq);
204 	timer->expires = jiffies + HZ;
205 	add_timer(timer);
206 
207 	return IRQ_HANDLED;
208 }
209 
dc21285_discard_irq(int irq,void * dev_id)210 static irqreturn_t dc21285_discard_irq(int irq, void *dev_id)
211 {
212 	printk(KERN_DEBUG "PCI: discard timer expired\n");
213 	*CSR_SA110_CNTL &= 0xffffde07;
214 
215 	return IRQ_HANDLED;
216 }
217 
dc21285_dparity_irq(int irq,void * dev_id)218 static irqreturn_t dc21285_dparity_irq(int irq, void *dev_id)
219 {
220 	unsigned int cmd;
221 
222 	printk(KERN_DEBUG "PCI: data parity error detected: ");
223 	pcibios_report_status(PCI_STATUS_PARITY | PCI_STATUS_DETECTED_PARITY, 1);
224 	printk("\n");
225 
226 	cmd = *CSR_PCICMD & 0xffff;
227 	*CSR_PCICMD = cmd | 1 << 24;
228 
229 	return IRQ_HANDLED;
230 }
231 
dc21285_parity_irq(int irq,void * dev_id)232 static irqreturn_t dc21285_parity_irq(int irq, void *dev_id)
233 {
234 	struct timer_list *timer = dev_id;
235 	unsigned int cmd;
236 
237 	printk(KERN_DEBUG "PCI: parity error detected: ");
238 	pcibios_report_status(PCI_STATUS_PARITY | PCI_STATUS_DETECTED_PARITY, 1);
239 	printk("\n");
240 
241 	cmd = *CSR_PCICMD & 0xffff;
242 	*CSR_PCICMD = cmd | 1 << 31;
243 
244 	/*
245 	 * back off this interrupt
246 	 */
247 	disable_irq(irq);
248 	timer->expires = jiffies + HZ;
249 	add_timer(timer);
250 
251 	return IRQ_HANDLED;
252 }
253 
dc21285_setup(int nr,struct pci_sys_data * sys)254 int __init dc21285_setup(int nr, struct pci_sys_data *sys)
255 {
256 	struct resource *res;
257 
258 	if (nr || !footbridge_cfn_mode())
259 		return 0;
260 
261 	res = kzalloc(sizeof(struct resource) * 2, GFP_KERNEL);
262 	if (!res) {
263 		printk("out of memory for root bus resources");
264 		return 0;
265 	}
266 
267 	res[0].flags = IORESOURCE_MEM;
268 	res[0].name  = "Footbridge non-prefetch";
269 	res[1].flags = IORESOURCE_MEM | IORESOURCE_PREFETCH;
270 	res[1].name  = "Footbridge prefetch";
271 
272 	allocate_resource(&iomem_resource, &res[1], 0x20000000,
273 			  0xa0000000, 0xffffffff, 0x20000000, NULL, NULL);
274 	allocate_resource(&iomem_resource, &res[0], 0x40000000,
275 			  0x80000000, 0xffffffff, 0x40000000, NULL, NULL);
276 
277 	sys->resource[0] = &ioport_resource;
278 	sys->resource[1] = &res[0];
279 	sys->resource[2] = &res[1];
280 	sys->mem_offset  = DC21285_PCI_MEM;
281 
282 	return 1;
283 }
284 
dc21285_scan_bus(int nr,struct pci_sys_data * sys)285 struct pci_bus * __init dc21285_scan_bus(int nr, struct pci_sys_data *sys)
286 {
287 	return pci_scan_bus(0, &dc21285_ops, sys);
288 }
289 
290 #define dc21285_request_irq(_a, _b, _c, _d, _e) \
291 	WARN_ON(request_irq(_a, _b, _c, _d, _e) < 0)
292 
dc21285_preinit(void)293 void __init dc21285_preinit(void)
294 {
295 	unsigned int mem_size, mem_mask;
296 	int cfn_mode;
297 
298 	mem_size = (unsigned int)high_memory - PAGE_OFFSET;
299 	for (mem_mask = 0x00100000; mem_mask < 0x10000000; mem_mask <<= 1)
300 		if (mem_mask >= mem_size)
301 			break;
302 
303 	/*
304 	 * These registers need to be set up whether we're the
305 	 * central function or not.
306 	 */
307 	*CSR_SDRAMBASEMASK    = (mem_mask - 1) & 0x0ffc0000;
308 	*CSR_SDRAMBASEOFFSET  = 0;
309 	*CSR_ROMBASEMASK      = 0x80000000;
310 	*CSR_CSRBASEMASK      = 0;
311 	*CSR_CSRBASEOFFSET    = 0;
312 	*CSR_PCIADDR_EXTN     = 0;
313 
314 	cfn_mode = __footbridge_cfn_mode();
315 
316 	printk(KERN_INFO "PCI: DC21285 footbridge, revision %02lX, in "
317 		"%s mode\n", *CSR_CLASSREV & 0xff, cfn_mode ?
318 		"central function" : "addin");
319 
320 	if (footbridge_cfn_mode()) {
321 		/*
322 		 * Clear any existing errors - we aren't
323 		 * interested in historical data...
324 		 */
325 		*CSR_SA110_CNTL	= (*CSR_SA110_CNTL & 0xffffde07) |
326 				  SA110_CNTL_RXSERR;
327 		*CSR_PCICMD = (*CSR_PCICMD & 0xffff) | PCICMD_ERROR_BITS;
328 	}
329 
330 	init_timer(&serr_timer);
331 	init_timer(&perr_timer);
332 
333 	serr_timer.data = IRQ_PCI_SERR;
334 	serr_timer.function = dc21285_enable_error;
335 	perr_timer.data = IRQ_PCI_PERR;
336 	perr_timer.function = dc21285_enable_error;
337 
338 	/*
339 	 * We don't care if these fail.
340 	 */
341 	dc21285_request_irq(IRQ_PCI_SERR, dc21285_serr_irq, IRQF_DISABLED,
342 			    "PCI system error", &serr_timer);
343 	dc21285_request_irq(IRQ_PCI_PERR, dc21285_parity_irq, IRQF_DISABLED,
344 			    "PCI parity error", &perr_timer);
345 	dc21285_request_irq(IRQ_PCI_ABORT, dc21285_abort_irq, IRQF_DISABLED,
346 			    "PCI abort", NULL);
347 	dc21285_request_irq(IRQ_DISCARD_TIMER, dc21285_discard_irq, IRQF_DISABLED,
348 			    "Discard timer", NULL);
349 	dc21285_request_irq(IRQ_PCI_DPERR, dc21285_dparity_irq, IRQF_DISABLED,
350 			    "PCI data parity", NULL);
351 
352 	if (cfn_mode) {
353 		static struct resource csrio;
354 
355 		csrio.flags  = IORESOURCE_IO;
356 		csrio.name   = "Footbridge";
357 
358 		allocate_resource(&ioport_resource, &csrio, 128,
359 				  0xff00, 0xffff, 128, NULL, NULL);
360 
361 		/*
362 		 * Map our SDRAM at a known address in PCI space, just in case
363 		 * the firmware had other ideas.  Using a nonzero base is
364 		 * necessary, since some VGA cards forcefully use PCI addresses
365 		 * in the range 0x000a0000 to 0x000c0000. (eg, S3 cards).
366 		 */
367 		*CSR_PCICSRBASE       = 0xf4000000;
368 		*CSR_PCICSRIOBASE     = csrio.start;
369 		*CSR_PCISDRAMBASE     = __virt_to_bus(PAGE_OFFSET);
370 		*CSR_PCIROMBASE       = 0;
371 		*CSR_PCICMD = PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER |
372 			      PCI_COMMAND_INVALIDATE | PCICMD_ERROR_BITS;
373 	} else if (footbridge_cfn_mode() != 0) {
374 		/*
375 		 * If we are not compiled to accept "add-in" mode, then
376 		 * we are using a constant virt_to_bus translation which
377 		 * can not hope to cater for the way the host BIOS  has
378 		 * set up the machine.
379 		 */
380 		panic("PCI: this kernel is compiled for central "
381 			"function mode only");
382 	}
383 }
384 
dc21285_postinit(void)385 void __init dc21285_postinit(void)
386 {
387 	register_isa_ports(DC21285_PCI_MEM, DC21285_PCI_IO, 0);
388 }
389