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 extern void pcibios_report_status(u_int status_mask, int warn);
35 
36 static unsigned long
37 dc21285_base_address(struct pci_bus *bus, unsigned int devfn)
38 {
39 	unsigned long addr = 0;
40 
41 	if (bus->number == 0) {
42 		if (PCI_SLOT(devfn) == 0)
43 			/*
44 			 * For devfn 0, point at the 21285
45 			 */
46 			addr = ARMCSR_BASE;
47 		else {
48 			devfn -= 1 << 3;
49 
50 			if (devfn < PCI_DEVFN(MAX_SLOTS, 0))
51 				addr = PCICFG0_BASE | 0xc00000 | (devfn << 8);
52 		}
53 	} else
54 		addr = PCICFG1_BASE | (bus->number << 16) | (devfn << 8);
55 
56 	return addr;
57 }
58 
59 static int
60 dc21285_read_config(struct pci_bus *bus, unsigned int devfn, int where,
61 		    int size, u32 *value)
62 {
63 	unsigned long addr = dc21285_base_address(bus, devfn);
64 	u32 v = 0xffffffff;
65 
66 	if (addr)
67 		switch (size) {
68 		case 1:
69 			asm("ldrb	%0, [%1, %2]"
70 				: "=r" (v) : "r" (addr), "r" (where) : "cc");
71 			break;
72 		case 2:
73 			asm("ldrh	%0, [%1, %2]"
74 				: "=r" (v) : "r" (addr), "r" (where) : "cc");
75 			break;
76 		case 4:
77 			asm("ldr	%0, [%1, %2]"
78 				: "=r" (v) : "r" (addr), "r" (where) : "cc");
79 			break;
80 		}
81 
82 	*value = v;
83 
84 	v = *CSR_PCICMD;
85 	if (v & PCICMD_ABORT) {
86 		*CSR_PCICMD = v & (0xffff|PCICMD_ABORT);
87 		return -1;
88 	}
89 
90 	return PCIBIOS_SUCCESSFUL;
91 }
92 
93 static int
94 dc21285_write_config(struct pci_bus *bus, unsigned int devfn, int where,
95 		     int size, u32 value)
96 {
97 	unsigned long addr = dc21285_base_address(bus, devfn);
98 	u32 v;
99 
100 	if (addr)
101 		switch (size) {
102 		case 1:
103 			asm("strb	%0, [%1, %2]"
104 				: : "r" (value), "r" (addr), "r" (where)
105 				: "cc");
106 			break;
107 		case 2:
108 			asm("strh	%0, [%1, %2]"
109 				: : "r" (value), "r" (addr), "r" (where)
110 				: "cc");
111 			break;
112 		case 4:
113 			asm("str	%0, [%1, %2]"
114 				: : "r" (value), "r" (addr), "r" (where)
115 				: "cc");
116 			break;
117 		}
118 
119 	v = *CSR_PCICMD;
120 	if (v & PCICMD_ABORT) {
121 		*CSR_PCICMD = v & (0xffff|PCICMD_ABORT);
122 		return -1;
123 	}
124 
125 	return PCIBIOS_SUCCESSFUL;
126 }
127 
128 struct pci_ops dc21285_ops = {
129 	.read	= dc21285_read_config,
130 	.write	= dc21285_write_config,
131 };
132 
133 static struct timer_list serr_timer;
134 static struct timer_list perr_timer;
135 
136 static void dc21285_enable_error(struct timer_list *timer)
137 {
138 	del_timer(timer);
139 
140 	if (timer == &serr_timer)
141 		enable_irq(IRQ_PCI_SERR);
142 	else if (timer == &perr_timer)
143 		enable_irq(IRQ_PCI_PERR);
144 }
145 
146 /*
147  * Warn on PCI errors.
148  */
149 static irqreturn_t dc21285_abort_irq(int irq, void *dev_id)
150 {
151 	unsigned int cmd;
152 	unsigned int status;
153 
154 	cmd = *CSR_PCICMD;
155 	status = cmd >> 16;
156 	cmd = cmd & 0xffff;
157 
158 	if (status & PCI_STATUS_REC_MASTER_ABORT) {
159 		printk(KERN_DEBUG "PCI: master abort, pc=0x%08lx\n",
160 			instruction_pointer(get_irq_regs()));
161 		cmd |= PCI_STATUS_REC_MASTER_ABORT << 16;
162 	}
163 
164 	if (status & PCI_STATUS_REC_TARGET_ABORT) {
165 		printk(KERN_DEBUG "PCI: target abort: ");
166 		pcibios_report_status(PCI_STATUS_REC_MASTER_ABORT |
167 				      PCI_STATUS_SIG_TARGET_ABORT |
168 				      PCI_STATUS_REC_TARGET_ABORT, 1);
169 		printk("\n");
170 
171 		cmd |= PCI_STATUS_REC_TARGET_ABORT << 16;
172 	}
173 
174 	*CSR_PCICMD = cmd;
175 
176 	return IRQ_HANDLED;
177 }
178 
179 static irqreturn_t dc21285_serr_irq(int irq, void *dev_id)
180 {
181 	struct timer_list *timer = dev_id;
182 	unsigned int cntl;
183 
184 	printk(KERN_DEBUG "PCI: system error received: ");
185 	pcibios_report_status(PCI_STATUS_SIG_SYSTEM_ERROR, 1);
186 	printk("\n");
187 
188 	cntl = *CSR_SA110_CNTL & 0xffffdf07;
189 	*CSR_SA110_CNTL = cntl | SA110_CNTL_RXSERR;
190 
191 	/*
192 	 * back off this interrupt
193 	 */
194 	disable_irq(irq);
195 	timer->expires = jiffies + HZ;
196 	add_timer(timer);
197 
198 	return IRQ_HANDLED;
199 }
200 
201 static irqreturn_t dc21285_discard_irq(int irq, void *dev_id)
202 {
203 	printk(KERN_DEBUG "PCI: discard timer expired\n");
204 	*CSR_SA110_CNTL &= 0xffffde07;
205 
206 	return IRQ_HANDLED;
207 }
208 
209 static irqreturn_t dc21285_dparity_irq(int irq, void *dev_id)
210 {
211 	unsigned int cmd;
212 
213 	printk(KERN_DEBUG "PCI: data parity error detected: ");
214 	pcibios_report_status(PCI_STATUS_PARITY | PCI_STATUS_DETECTED_PARITY, 1);
215 	printk("\n");
216 
217 	cmd = *CSR_PCICMD & 0xffff;
218 	*CSR_PCICMD = cmd | 1 << 24;
219 
220 	return IRQ_HANDLED;
221 }
222 
223 static irqreturn_t dc21285_parity_irq(int irq, void *dev_id)
224 {
225 	struct timer_list *timer = dev_id;
226 	unsigned int cmd;
227 
228 	printk(KERN_DEBUG "PCI: parity error detected: ");
229 	pcibios_report_status(PCI_STATUS_PARITY | PCI_STATUS_DETECTED_PARITY, 1);
230 	printk("\n");
231 
232 	cmd = *CSR_PCICMD & 0xffff;
233 	*CSR_PCICMD = cmd | 1 << 31;
234 
235 	/*
236 	 * back off this interrupt
237 	 */
238 	disable_irq(irq);
239 	timer->expires = jiffies + HZ;
240 	add_timer(timer);
241 
242 	return IRQ_HANDLED;
243 }
244 
245 int __init dc21285_setup(int nr, struct pci_sys_data *sys)
246 {
247 	struct resource *res;
248 
249 	if (nr || !footbridge_cfn_mode())
250 		return 0;
251 
252 	res = kcalloc(2, sizeof(struct resource), GFP_KERNEL);
253 	if (!res) {
254 		printk("out of memory for root bus resources");
255 		return 0;
256 	}
257 
258 	res[0].flags = IORESOURCE_MEM;
259 	res[0].name  = "Footbridge non-prefetch";
260 	res[1].flags = IORESOURCE_MEM | IORESOURCE_PREFETCH;
261 	res[1].name  = "Footbridge prefetch";
262 
263 	allocate_resource(&iomem_resource, &res[1], 0x20000000,
264 			  0xa0000000, 0xffffffff, 0x20000000, NULL, NULL);
265 	allocate_resource(&iomem_resource, &res[0], 0x40000000,
266 			  0x80000000, 0xffffffff, 0x40000000, NULL, NULL);
267 
268 	sys->mem_offset  = DC21285_PCI_MEM;
269 
270 	pci_add_resource_offset(&sys->resources, &res[0], sys->mem_offset);
271 	pci_add_resource_offset(&sys->resources, &res[1], sys->mem_offset);
272 
273 	return 1;
274 }
275 
276 #define dc21285_request_irq(_a, _b, _c, _d, _e) \
277 	WARN_ON(request_irq(_a, _b, _c, _d, _e) < 0)
278 
279 void __init dc21285_preinit(void)
280 {
281 	unsigned int mem_size, mem_mask;
282 	int cfn_mode;
283 
284 	pcibios_min_mem = 0x81000000;
285 
286 	mem_size = (unsigned int)high_memory - PAGE_OFFSET;
287 	for (mem_mask = 0x00100000; mem_mask < 0x10000000; mem_mask <<= 1)
288 		if (mem_mask >= mem_size)
289 			break;
290 
291 	/*
292 	 * These registers need to be set up whether we're the
293 	 * central function or not.
294 	 */
295 	*CSR_SDRAMBASEMASK    = (mem_mask - 1) & 0x0ffc0000;
296 	*CSR_SDRAMBASEOFFSET  = 0;
297 	*CSR_ROMBASEMASK      = 0x80000000;
298 	*CSR_CSRBASEMASK      = 0;
299 	*CSR_CSRBASEOFFSET    = 0;
300 	*CSR_PCIADDR_EXTN     = 0;
301 
302 	cfn_mode = __footbridge_cfn_mode();
303 
304 	printk(KERN_INFO "PCI: DC21285 footbridge, revision %02lX, in "
305 		"%s mode\n", *CSR_CLASSREV & 0xff, cfn_mode ?
306 		"central function" : "addin");
307 
308 	if (footbridge_cfn_mode()) {
309 		/*
310 		 * Clear any existing errors - we aren't
311 		 * interested in historical data...
312 		 */
313 		*CSR_SA110_CNTL	= (*CSR_SA110_CNTL & 0xffffde07) |
314 				  SA110_CNTL_RXSERR;
315 		*CSR_PCICMD = (*CSR_PCICMD & 0xffff) | PCICMD_ERROR_BITS;
316 	}
317 
318 	timer_setup(&serr_timer, dc21285_enable_error, 0);
319 	timer_setup(&perr_timer, dc21285_enable_error, 0);
320 
321 	/*
322 	 * We don't care if these fail.
323 	 */
324 	dc21285_request_irq(IRQ_PCI_SERR, dc21285_serr_irq, 0,
325 			    "PCI system error", &serr_timer);
326 	dc21285_request_irq(IRQ_PCI_PERR, dc21285_parity_irq, 0,
327 			    "PCI parity error", &perr_timer);
328 	dc21285_request_irq(IRQ_PCI_ABORT, dc21285_abort_irq, 0,
329 			    "PCI abort", NULL);
330 	dc21285_request_irq(IRQ_DISCARD_TIMER, dc21285_discard_irq, 0,
331 			    "Discard timer", NULL);
332 	dc21285_request_irq(IRQ_PCI_DPERR, dc21285_dparity_irq, 0,
333 			    "PCI data parity", NULL);
334 
335 	if (cfn_mode) {
336 		/*
337 		 * Map our SDRAM at a known address in PCI space, just in case
338 		 * the firmware had other ideas.  Using a nonzero base is
339 		 * necessary, since some VGA cards forcefully use PCI addresses
340 		 * in the range 0x000a0000 to 0x000c0000. (eg, S3 cards).
341 		 */
342 		*CSR_PCICSRBASE       = 0xf4000000;
343 		*CSR_PCICSRIOBASE     = 0;
344 		*CSR_PCISDRAMBASE     = __virt_to_bus(PAGE_OFFSET);
345 		*CSR_PCIROMBASE       = 0;
346 		*CSR_PCICMD = PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER |
347 			      PCI_COMMAND_INVALIDATE | PCICMD_ERROR_BITS;
348 	} else if (footbridge_cfn_mode() != 0) {
349 		/*
350 		 * If we are not compiled to accept "add-in" mode, then
351 		 * we are using a constant virt_to_bus translation which
352 		 * can not hope to cater for the way the host BIOS  has
353 		 * set up the machine.
354 		 */
355 		panic("PCI: this kernel is compiled for central "
356 			"function mode only");
357 	}
358 }
359 
360 void __init dc21285_postinit(void)
361 {
362 	register_isa_ports(DC21285_PCI_MEM, DC21285_PCI_IO, 0);
363 }
364