1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  linux/arch/arm/kernel/dec21285.c: PCI functions for DC21285
4  *
5  *  Copyright (C) 1998-2001 Russell King
6  *  Copyright (C) 1998-2000 Phil Blundell
7  */
8 #include <linux/kernel.h>
9 #include <linux/pci.h>
10 #include <linux/interrupt.h>
11 #include <linux/mm.h>
12 #include <linux/slab.h>
13 #include <linux/init.h>
14 #include <linux/ioport.h>
15 #include <linux/irq.h>
16 #include <linux/io.h>
17 #include <linux/spinlock.h>
18 
19 #include <asm/irq.h>
20 #include <asm/mach/pci.h>
21 #include <asm/hardware/dec21285.h>
22 
23 #define MAX_SLOTS		21
24 
25 #define PCICMD_ABORT		((PCI_STATUS_REC_MASTER_ABORT| \
26 				  PCI_STATUS_REC_TARGET_ABORT)<<16)
27 
28 #define PCICMD_ERROR_BITS	((PCI_STATUS_DETECTED_PARITY | \
29 				  PCI_STATUS_REC_MASTER_ABORT | \
30 				  PCI_STATUS_REC_TARGET_ABORT | \
31 				  PCI_STATUS_PARITY) << 16)
32 
33 extern int setup_arm_irq(int, struct irqaction *);
34 
35 static unsigned long
dc21285_base_address(struct pci_bus * bus,unsigned int devfn)36 dc21285_base_address(struct pci_bus *bus, unsigned int devfn)
37 {
38 	unsigned long addr = 0;
39 
40 	if (bus->number == 0) {
41 		if (PCI_SLOT(devfn) == 0)
42 			/*
43 			 * For devfn 0, point at the 21285
44 			 */
45 			addr = ARMCSR_BASE;
46 		else {
47 			devfn -= 1 << 3;
48 
49 			if (devfn < PCI_DEVFN(MAX_SLOTS, 0))
50 				addr = PCICFG0_BASE | 0xc00000 | (devfn << 8);
51 		}
52 	} else
53 		addr = PCICFG1_BASE | (bus->number << 16) | (devfn << 8);
54 
55 	return addr;
56 }
57 
58 static int
dc21285_read_config(struct pci_bus * bus,unsigned int devfn,int where,int size,u32 * value)59 dc21285_read_config(struct pci_bus *bus, unsigned int devfn, int where,
60 		    int size, u32 *value)
61 {
62 	unsigned long addr = dc21285_base_address(bus, devfn);
63 	u32 v = 0xffffffff;
64 
65 	if (addr)
66 		switch (size) {
67 		case 1:
68 			asm volatile("ldrb	%0, [%1, %2]"
69 				: "=r" (v) : "r" (addr), "r" (where) : "cc");
70 			break;
71 		case 2:
72 			asm volatile("ldrh	%0, [%1, %2]"
73 				: "=r" (v) : "r" (addr), "r" (where) : "cc");
74 			break;
75 		case 4:
76 			asm volatile("ldr	%0, [%1, %2]"
77 				: "=r" (v) : "r" (addr), "r" (where) : "cc");
78 			break;
79 		}
80 
81 	*value = v;
82 
83 	v = *CSR_PCICMD;
84 	if (v & PCICMD_ABORT) {
85 		*CSR_PCICMD = v & (0xffff|PCICMD_ABORT);
86 		return -1;
87 	}
88 
89 	return PCIBIOS_SUCCESSFUL;
90 }
91 
92 static int
dc21285_write_config(struct pci_bus * bus,unsigned int devfn,int where,int size,u32 value)93 dc21285_write_config(struct pci_bus *bus, unsigned int devfn, int where,
94 		     int size, u32 value)
95 {
96 	unsigned long addr = dc21285_base_address(bus, devfn);
97 	u32 v;
98 
99 	if (addr)
100 		switch (size) {
101 		case 1:
102 			asm volatile("strb	%0, [%1, %2]"
103 				: : "r" (value), "r" (addr), "r" (where)
104 				: "cc");
105 			break;
106 		case 2:
107 			asm volatile("strh	%0, [%1, %2]"
108 				: : "r" (value), "r" (addr), "r" (where)
109 				: "cc");
110 			break;
111 		case 4:
112 			asm volatile("str	%0, [%1, %2]"
113 				: : "r" (value), "r" (addr), "r" (where)
114 				: "cc");
115 			break;
116 		}
117 
118 	v = *CSR_PCICMD;
119 	if (v & PCICMD_ABORT) {
120 		*CSR_PCICMD = v & (0xffff|PCICMD_ABORT);
121 		return -1;
122 	}
123 
124 	return PCIBIOS_SUCCESSFUL;
125 }
126 
127 struct pci_ops dc21285_ops = {
128 	.read	= dc21285_read_config,
129 	.write	= dc21285_write_config,
130 };
131 
132 static struct timer_list serr_timer;
133 static struct timer_list perr_timer;
134 
dc21285_enable_error(struct timer_list * timer)135 static void dc21285_enable_error(struct timer_list *timer)
136 {
137 	del_timer(timer);
138 
139 	if (timer == &serr_timer)
140 		enable_irq(IRQ_PCI_SERR);
141 	else if (timer == &perr_timer)
142 		enable_irq(IRQ_PCI_PERR);
143 }
144 
145 /*
146  * Warn on PCI errors.
147  */
dc21285_abort_irq(int irq,void * dev_id)148 static irqreturn_t dc21285_abort_irq(int irq, void *dev_id)
149 {
150 	unsigned int cmd;
151 	unsigned int status;
152 
153 	cmd = *CSR_PCICMD;
154 	status = cmd >> 16;
155 	cmd = cmd & 0xffff;
156 
157 	if (status & PCI_STATUS_REC_MASTER_ABORT) {
158 		printk(KERN_DEBUG "PCI: master abort, pc=0x%08lx\n",
159 			instruction_pointer(get_irq_regs()));
160 		cmd |= PCI_STATUS_REC_MASTER_ABORT << 16;
161 	}
162 
163 	if (status & PCI_STATUS_REC_TARGET_ABORT) {
164 		printk(KERN_DEBUG "PCI: target abort: ");
165 		pcibios_report_status(PCI_STATUS_REC_MASTER_ABORT |
166 				      PCI_STATUS_SIG_TARGET_ABORT |
167 				      PCI_STATUS_REC_TARGET_ABORT, 1);
168 		printk("\n");
169 
170 		cmd |= PCI_STATUS_REC_TARGET_ABORT << 16;
171 	}
172 
173 	*CSR_PCICMD = cmd;
174 
175 	return IRQ_HANDLED;
176 }
177 
dc21285_serr_irq(int irq,void * dev_id)178 static irqreturn_t dc21285_serr_irq(int irq, void *dev_id)
179 {
180 	struct timer_list *timer = dev_id;
181 	unsigned int cntl;
182 
183 	printk(KERN_DEBUG "PCI: system error received: ");
184 	pcibios_report_status(PCI_STATUS_SIG_SYSTEM_ERROR, 1);
185 	printk("\n");
186 
187 	cntl = *CSR_SA110_CNTL & 0xffffdf07;
188 	*CSR_SA110_CNTL = cntl | SA110_CNTL_RXSERR;
189 
190 	/*
191 	 * back off this interrupt
192 	 */
193 	disable_irq(irq);
194 	timer->expires = jiffies + HZ;
195 	add_timer(timer);
196 
197 	return IRQ_HANDLED;
198 }
199 
dc21285_discard_irq(int irq,void * dev_id)200 static irqreturn_t dc21285_discard_irq(int irq, void *dev_id)
201 {
202 	printk(KERN_DEBUG "PCI: discard timer expired\n");
203 	*CSR_SA110_CNTL &= 0xffffde07;
204 
205 	return IRQ_HANDLED;
206 }
207 
dc21285_dparity_irq(int irq,void * dev_id)208 static irqreturn_t dc21285_dparity_irq(int irq, void *dev_id)
209 {
210 	unsigned int cmd;
211 
212 	printk(KERN_DEBUG "PCI: data parity error detected: ");
213 	pcibios_report_status(PCI_STATUS_PARITY | PCI_STATUS_DETECTED_PARITY, 1);
214 	printk("\n");
215 
216 	cmd = *CSR_PCICMD & 0xffff;
217 	*CSR_PCICMD = cmd | 1 << 24;
218 
219 	return IRQ_HANDLED;
220 }
221 
dc21285_parity_irq(int irq,void * dev_id)222 static irqreturn_t dc21285_parity_irq(int irq, void *dev_id)
223 {
224 	struct timer_list *timer = dev_id;
225 	unsigned int cmd;
226 
227 	printk(KERN_DEBUG "PCI: parity error detected: ");
228 	pcibios_report_status(PCI_STATUS_PARITY | PCI_STATUS_DETECTED_PARITY, 1);
229 	printk("\n");
230 
231 	cmd = *CSR_PCICMD & 0xffff;
232 	*CSR_PCICMD = cmd | 1 << 31;
233 
234 	/*
235 	 * back off this interrupt
236 	 */
237 	disable_irq(irq);
238 	timer->expires = jiffies + HZ;
239 	add_timer(timer);
240 
241 	return IRQ_HANDLED;
242 }
243 
dc21285_setup(int nr,struct pci_sys_data * sys)244 int __init dc21285_setup(int nr, struct pci_sys_data *sys)
245 {
246 	struct resource *res;
247 
248 	if (nr || !footbridge_cfn_mode())
249 		return 0;
250 
251 	res = kcalloc(2, sizeof(struct resource), GFP_KERNEL);
252 	if (!res) {
253 		printk("out of memory for root bus resources");
254 		return 0;
255 	}
256 
257 	res[0].flags = IORESOURCE_MEM;
258 	res[0].name  = "Footbridge non-prefetch";
259 	res[1].flags = IORESOURCE_MEM | IORESOURCE_PREFETCH;
260 	res[1].name  = "Footbridge prefetch";
261 
262 	allocate_resource(&iomem_resource, &res[1], 0x20000000,
263 			  0xa0000000, 0xffffffff, 0x20000000, NULL, NULL);
264 	allocate_resource(&iomem_resource, &res[0], 0x40000000,
265 			  0x80000000, 0xffffffff, 0x40000000, NULL, NULL);
266 
267 	sys->mem_offset  = DC21285_PCI_MEM;
268 
269 	pci_add_resource_offset(&sys->resources, &res[0], sys->mem_offset);
270 	pci_add_resource_offset(&sys->resources, &res[1], sys->mem_offset);
271 
272 	return 1;
273 }
274 
275 #define dc21285_request_irq(_a, _b, _c, _d, _e) \
276 	WARN_ON(request_irq(_a, _b, _c, _d, _e) < 0)
277 
dc21285_preinit(void)278 void __init dc21285_preinit(void)
279 {
280 	unsigned int mem_size, mem_mask;
281 	int cfn_mode;
282 
283 	pcibios_min_mem = 0x81000000;
284 
285 	mem_size = (unsigned int)high_memory - PAGE_OFFSET;
286 	for (mem_mask = 0x00100000; mem_mask < 0x10000000; mem_mask <<= 1)
287 		if (mem_mask >= mem_size)
288 			break;
289 
290 	/*
291 	 * These registers need to be set up whether we're the
292 	 * central function or not.
293 	 */
294 	*CSR_SDRAMBASEMASK    = (mem_mask - 1) & 0x0ffc0000;
295 	*CSR_SDRAMBASEOFFSET  = 0;
296 	*CSR_ROMBASEMASK      = 0x80000000;
297 	*CSR_CSRBASEMASK      = 0;
298 	*CSR_CSRBASEOFFSET    = 0;
299 	*CSR_PCIADDR_EXTN     = 0;
300 
301 	cfn_mode = __footbridge_cfn_mode();
302 
303 	printk(KERN_INFO "PCI: DC21285 footbridge, revision %02lX, in "
304 		"%s mode\n", *CSR_CLASSREV & 0xff, cfn_mode ?
305 		"central function" : "addin");
306 
307 	if (footbridge_cfn_mode()) {
308 		/*
309 		 * Clear any existing errors - we aren't
310 		 * interested in historical data...
311 		 */
312 		*CSR_SA110_CNTL	= (*CSR_SA110_CNTL & 0xffffde07) |
313 				  SA110_CNTL_RXSERR;
314 		*CSR_PCICMD = (*CSR_PCICMD & 0xffff) | PCICMD_ERROR_BITS;
315 	}
316 
317 	timer_setup(&serr_timer, dc21285_enable_error, 0);
318 	timer_setup(&perr_timer, dc21285_enable_error, 0);
319 
320 	/*
321 	 * We don't care if these fail.
322 	 */
323 	dc21285_request_irq(IRQ_PCI_SERR, dc21285_serr_irq, 0,
324 			    "PCI system error", &serr_timer);
325 	dc21285_request_irq(IRQ_PCI_PERR, dc21285_parity_irq, 0,
326 			    "PCI parity error", &perr_timer);
327 	dc21285_request_irq(IRQ_PCI_ABORT, dc21285_abort_irq, 0,
328 			    "PCI abort", NULL);
329 	dc21285_request_irq(IRQ_DISCARD_TIMER, dc21285_discard_irq, 0,
330 			    "Discard timer", NULL);
331 	dc21285_request_irq(IRQ_PCI_DPERR, dc21285_dparity_irq, 0,
332 			    "PCI data parity", NULL);
333 
334 	if (cfn_mode) {
335 		/*
336 		 * Map our SDRAM at a known address in PCI space, just in case
337 		 * the firmware had other ideas.  Using a nonzero base is
338 		 * necessary, since some VGA cards forcefully use PCI addresses
339 		 * in the range 0x000a0000 to 0x000c0000. (eg, S3 cards).
340 		 */
341 		*CSR_PCICSRBASE       = 0xf4000000;
342 		*CSR_PCICSRIOBASE     = 0;
343 		*CSR_PCISDRAMBASE     = __virt_to_bus(PAGE_OFFSET);
344 		*CSR_PCIROMBASE       = 0;
345 		*CSR_PCICMD = PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER |
346 			      PCI_COMMAND_INVALIDATE | PCICMD_ERROR_BITS;
347 	} else if (footbridge_cfn_mode() != 0) {
348 		/*
349 		 * If we are not compiled to accept "add-in" mode, then
350 		 * we are using a constant virt_to_bus translation which
351 		 * can not hope to cater for the way the host BIOS  has
352 		 * set up the machine.
353 		 */
354 		panic("PCI: this kernel is compiled for central "
355 			"function mode only");
356 	}
357 }
358 
dc21285_postinit(void)359 void __init dc21285_postinit(void)
360 {
361 	register_isa_ports(DC21285_PCI_MEM, DC21285_PCI_IO, 0);
362 }
363