1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * arch/arm/mach-ixp4xx/common-pci.c
4 *
5 * IXP4XX PCI routines for all platforms
6 *
7 * Maintainer: Deepak Saxena <dsaxena@plexity.net>
8 *
9 * Copyright (C) 2002 Intel Corporation.
10 * Copyright (C) 2003 Greg Ungerer <gerg@snapgear.com>
11 * Copyright (C) 2003-2004 MontaVista Software, Inc.
12 */
13
14 #include <linux/sched.h>
15 #include <linux/kernel.h>
16 #include <linux/pci.h>
17 #include <linux/interrupt.h>
18 #include <linux/mm.h>
19 #include <linux/init.h>
20 #include <linux/ioport.h>
21 #include <linux/slab.h>
22 #include <linux/delay.h>
23 #include <linux/device.h>
24 #include <linux/io.h>
25 #include <linux/export.h>
26 #include <asm/dma-mapping.h>
27
28 #include <asm/cputype.h>
29 #include <asm/irq.h>
30 #include <linux/sizes.h>
31 #include <asm/mach/pci.h>
32 #include <mach/hardware.h>
33
34
35 /*
36 * IXP4xx PCI read function is dependent on whether we are
37 * running A0 or B0 (AppleGate) silicon.
38 */
39 int (*ixp4xx_pci_read)(u32 addr, u32 cmd, u32* data);
40
41 /*
42 * Base address for PCI register region
43 */
44 unsigned long ixp4xx_pci_reg_base = 0;
45
46 /*
47 * PCI cfg an I/O routines are done by programming a
48 * command/byte enable register, and then read/writing
49 * the data from a data register. We need to ensure
50 * these transactions are atomic or we will end up
51 * with corrupt data on the bus or in a driver.
52 */
53 static DEFINE_RAW_SPINLOCK(ixp4xx_pci_lock);
54
55 /*
56 * Read from PCI config space
57 */
crp_read(u32 ad_cbe,u32 * data)58 static void crp_read(u32 ad_cbe, u32 *data)
59 {
60 unsigned long flags;
61 raw_spin_lock_irqsave(&ixp4xx_pci_lock, flags);
62 *PCI_CRP_AD_CBE = ad_cbe;
63 *data = *PCI_CRP_RDATA;
64 raw_spin_unlock_irqrestore(&ixp4xx_pci_lock, flags);
65 }
66
67 /*
68 * Write to PCI config space
69 */
crp_write(u32 ad_cbe,u32 data)70 static void crp_write(u32 ad_cbe, u32 data)
71 {
72 unsigned long flags;
73 raw_spin_lock_irqsave(&ixp4xx_pci_lock, flags);
74 *PCI_CRP_AD_CBE = CRP_AD_CBE_WRITE | ad_cbe;
75 *PCI_CRP_WDATA = data;
76 raw_spin_unlock_irqrestore(&ixp4xx_pci_lock, flags);
77 }
78
check_master_abort(void)79 static inline int check_master_abort(void)
80 {
81 /* check Master Abort bit after access */
82 unsigned long isr = *PCI_ISR;
83
84 if (isr & PCI_ISR_PFE) {
85 /* make sure the Master Abort bit is reset */
86 *PCI_ISR = PCI_ISR_PFE;
87 pr_debug("%s failed\n", __func__);
88 return 1;
89 }
90
91 return 0;
92 }
93
ixp4xx_pci_read_errata(u32 addr,u32 cmd,u32 * data)94 int ixp4xx_pci_read_errata(u32 addr, u32 cmd, u32* data)
95 {
96 unsigned long flags;
97 int retval = 0;
98 int i;
99
100 raw_spin_lock_irqsave(&ixp4xx_pci_lock, flags);
101
102 *PCI_NP_AD = addr;
103
104 /*
105 * PCI workaround - only works if NP PCI space reads have
106 * no side effects!!! Read 8 times. last one will be good.
107 */
108 for (i = 0; i < 8; i++) {
109 *PCI_NP_CBE = cmd;
110 *data = *PCI_NP_RDATA;
111 *data = *PCI_NP_RDATA;
112 }
113
114 if(check_master_abort())
115 retval = 1;
116
117 raw_spin_unlock_irqrestore(&ixp4xx_pci_lock, flags);
118 return retval;
119 }
120
ixp4xx_pci_read_no_errata(u32 addr,u32 cmd,u32 * data)121 int ixp4xx_pci_read_no_errata(u32 addr, u32 cmd, u32* data)
122 {
123 unsigned long flags;
124 int retval = 0;
125
126 raw_spin_lock_irqsave(&ixp4xx_pci_lock, flags);
127
128 *PCI_NP_AD = addr;
129
130 /* set up and execute the read */
131 *PCI_NP_CBE = cmd;
132
133 /* the result of the read is now in NP_RDATA */
134 *data = *PCI_NP_RDATA;
135
136 if(check_master_abort())
137 retval = 1;
138
139 raw_spin_unlock_irqrestore(&ixp4xx_pci_lock, flags);
140 return retval;
141 }
142
ixp4xx_pci_write(u32 addr,u32 cmd,u32 data)143 int ixp4xx_pci_write(u32 addr, u32 cmd, u32 data)
144 {
145 unsigned long flags;
146 int retval = 0;
147
148 raw_spin_lock_irqsave(&ixp4xx_pci_lock, flags);
149
150 *PCI_NP_AD = addr;
151
152 /* set up the write */
153 *PCI_NP_CBE = cmd;
154
155 /* execute the write by writing to NP_WDATA */
156 *PCI_NP_WDATA = data;
157
158 if(check_master_abort())
159 retval = 1;
160
161 raw_spin_unlock_irqrestore(&ixp4xx_pci_lock, flags);
162 return retval;
163 }
164
ixp4xx_config_addr(u8 bus_num,u16 devfn,int where)165 static u32 ixp4xx_config_addr(u8 bus_num, u16 devfn, int where)
166 {
167 u32 addr;
168 if (!bus_num) {
169 /* type 0 */
170 addr = BIT(32-PCI_SLOT(devfn)) | ((PCI_FUNC(devfn)) << 8) |
171 (where & ~3);
172 } else {
173 /* type 1 */
174 addr = (bus_num << 16) | ((PCI_SLOT(devfn)) << 11) |
175 ((PCI_FUNC(devfn)) << 8) | (where & ~3) | 1;
176 }
177 return addr;
178 }
179
180 /*
181 * Mask table, bits to mask for quantity of size 1, 2 or 4 bytes.
182 * 0 and 3 are not valid indexes...
183 */
184 static u32 bytemask[] = {
185 /*0*/ 0,
186 /*1*/ 0xff,
187 /*2*/ 0xffff,
188 /*3*/ 0,
189 /*4*/ 0xffffffff,
190 };
191
local_byte_lane_enable_bits(u32 n,int size)192 static u32 local_byte_lane_enable_bits(u32 n, int size)
193 {
194 if (size == 1)
195 return (0xf & ~BIT(n)) << CRP_AD_CBE_BESL;
196 if (size == 2)
197 return (0xf & ~(BIT(n) | BIT(n+1))) << CRP_AD_CBE_BESL;
198 if (size == 4)
199 return 0;
200 return 0xffffffff;
201 }
202
local_read_config(int where,int size,u32 * value)203 static int local_read_config(int where, int size, u32 *value)
204 {
205 u32 n, data;
206 pr_debug("local_read_config from %d size %d\n", where, size);
207 n = where % 4;
208 crp_read(where & ~3, &data);
209 *value = (data >> (8*n)) & bytemask[size];
210 pr_debug("local_read_config read %#x\n", *value);
211 return PCIBIOS_SUCCESSFUL;
212 }
213
local_write_config(int where,int size,u32 value)214 static int local_write_config(int where, int size, u32 value)
215 {
216 u32 n, byte_enables, data;
217 pr_debug("local_write_config %#x to %d size %d\n", value, where, size);
218 n = where % 4;
219 byte_enables = local_byte_lane_enable_bits(n, size);
220 if (byte_enables == 0xffffffff)
221 return PCIBIOS_BAD_REGISTER_NUMBER;
222 data = value << (8*n);
223 crp_write((where & ~3) | byte_enables, data);
224 return PCIBIOS_SUCCESSFUL;
225 }
226
byte_lane_enable_bits(u32 n,int size)227 static u32 byte_lane_enable_bits(u32 n, int size)
228 {
229 if (size == 1)
230 return (0xf & ~BIT(n)) << 4;
231 if (size == 2)
232 return (0xf & ~(BIT(n) | BIT(n+1))) << 4;
233 if (size == 4)
234 return 0;
235 return 0xffffffff;
236 }
237
ixp4xx_pci_read_config(struct pci_bus * bus,unsigned int devfn,int where,int size,u32 * value)238 static int ixp4xx_pci_read_config(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *value)
239 {
240 u32 n, byte_enables, addr, data;
241 u8 bus_num = bus->number;
242
243 pr_debug("read_config from %d size %d dev %d:%d:%d\n", where, size,
244 bus_num, PCI_SLOT(devfn), PCI_FUNC(devfn));
245
246 *value = 0xffffffff;
247 n = where % 4;
248 byte_enables = byte_lane_enable_bits(n, size);
249 if (byte_enables == 0xffffffff)
250 return PCIBIOS_BAD_REGISTER_NUMBER;
251
252 addr = ixp4xx_config_addr(bus_num, devfn, where);
253 if (ixp4xx_pci_read(addr, byte_enables | NP_CMD_CONFIGREAD, &data))
254 return PCIBIOS_DEVICE_NOT_FOUND;
255
256 *value = (data >> (8*n)) & bytemask[size];
257 pr_debug("read_config_byte read %#x\n", *value);
258 return PCIBIOS_SUCCESSFUL;
259 }
260
ixp4xx_pci_write_config(struct pci_bus * bus,unsigned int devfn,int where,int size,u32 value)261 static int ixp4xx_pci_write_config(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 value)
262 {
263 u32 n, byte_enables, addr, data;
264 u8 bus_num = bus->number;
265
266 pr_debug("write_config_byte %#x to %d size %d dev %d:%d:%d\n", value, where,
267 size, bus_num, PCI_SLOT(devfn), PCI_FUNC(devfn));
268
269 n = where % 4;
270 byte_enables = byte_lane_enable_bits(n, size);
271 if (byte_enables == 0xffffffff)
272 return PCIBIOS_BAD_REGISTER_NUMBER;
273
274 addr = ixp4xx_config_addr(bus_num, devfn, where);
275 data = value << (8*n);
276 if (ixp4xx_pci_write(addr, byte_enables | NP_CMD_CONFIGWRITE, data))
277 return PCIBIOS_DEVICE_NOT_FOUND;
278
279 return PCIBIOS_SUCCESSFUL;
280 }
281
282 struct pci_ops ixp4xx_ops = {
283 .read = ixp4xx_pci_read_config,
284 .write = ixp4xx_pci_write_config,
285 };
286
287 /*
288 * PCI abort handler
289 */
abort_handler(unsigned long addr,unsigned int fsr,struct pt_regs * regs)290 static int abort_handler(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
291 {
292 u32 isr, status;
293
294 isr = *PCI_ISR;
295 local_read_config(PCI_STATUS, 2, &status);
296 pr_debug("PCI: abort_handler addr = %#lx, isr = %#x, "
297 "status = %#x\n", addr, isr, status);
298
299 /* make sure the Master Abort bit is reset */
300 *PCI_ISR = PCI_ISR_PFE;
301 status |= PCI_STATUS_REC_MASTER_ABORT;
302 local_write_config(PCI_STATUS, 2, status);
303
304 /*
305 * If it was an imprecise abort, then we need to correct the
306 * return address to be _after_ the instruction.
307 */
308 if (fsr & (1 << 10))
309 regs->ARM_pc += 4;
310
311 return 0;
312 }
313
ixp4xx_pci_preinit(void)314 void __init ixp4xx_pci_preinit(void)
315 {
316 unsigned long cpuid = read_cpuid_id();
317
318 #ifdef CONFIG_IXP4XX_INDIRECT_PCI
319 pcibios_min_mem = 0x10000000; /* 1 GB of indirect PCI MMIO space */
320 #else
321 pcibios_min_mem = 0x48000000; /* 64 MB of PCI MMIO space */
322 #endif
323 /*
324 * Determine which PCI read method to use.
325 * Rev 0 IXP425 requires workaround.
326 */
327 if (!(cpuid & 0xf) && cpu_is_ixp42x()) {
328 printk("PCI: IXP42x A0 silicon detected - "
329 "PCI Non-Prefetch Workaround Enabled\n");
330 ixp4xx_pci_read = ixp4xx_pci_read_errata;
331 } else
332 ixp4xx_pci_read = ixp4xx_pci_read_no_errata;
333
334
335 /* hook in our fault handler for PCI errors */
336 hook_fault_code(16+6, abort_handler, SIGBUS, 0,
337 "imprecise external abort");
338
339 pr_debug("setup PCI-AHB(inbound) and AHB-PCI(outbound) address mappings\n");
340
341 /*
342 * We use identity AHB->PCI address translation
343 * in the 0x48000000 to 0x4bffffff address space
344 */
345 *PCI_PCIMEMBASE = 0x48494A4B;
346
347 /*
348 * We also use identity PCI->AHB address translation
349 * in 4 16MB BARs that begin at the physical memory start
350 */
351 *PCI_AHBMEMBASE = (PHYS_OFFSET & 0xFF000000) +
352 ((PHYS_OFFSET & 0xFF000000) >> 8) +
353 ((PHYS_OFFSET & 0xFF000000) >> 16) +
354 ((PHYS_OFFSET & 0xFF000000) >> 24) +
355 0x00010203;
356
357 if (*PCI_CSR & PCI_CSR_HOST) {
358 printk("PCI: IXP4xx is host\n");
359
360 pr_debug("setup BARs in controller\n");
361
362 /*
363 * We configure the PCI inbound memory windows to be
364 * 1:1 mapped to SDRAM
365 */
366 local_write_config(PCI_BASE_ADDRESS_0, 4, PHYS_OFFSET);
367 local_write_config(PCI_BASE_ADDRESS_1, 4, PHYS_OFFSET + SZ_16M);
368 local_write_config(PCI_BASE_ADDRESS_2, 4, PHYS_OFFSET + SZ_32M);
369 local_write_config(PCI_BASE_ADDRESS_3, 4,
370 PHYS_OFFSET + SZ_32M + SZ_16M);
371
372 /*
373 * Enable CSR window at 64 MiB to allow PCI masters
374 * to continue prefetching past 64 MiB boundary.
375 */
376 local_write_config(PCI_BASE_ADDRESS_4, 4, PHYS_OFFSET + SZ_64M);
377
378 /*
379 * Enable the IO window to be way up high, at 0xfffffc00
380 */
381 local_write_config(PCI_BASE_ADDRESS_5, 4, 0xfffffc01);
382 local_write_config(0x40, 4, 0x000080FF); /* No TRDY time limit */
383 } else {
384 printk("PCI: IXP4xx is target - No bus scan performed\n");
385 }
386
387 printk("PCI: IXP4xx Using %s access for memory space\n",
388 #ifndef CONFIG_IXP4XX_INDIRECT_PCI
389 "direct"
390 #else
391 "indirect"
392 #endif
393 );
394
395 pr_debug("clear error bits in ISR\n");
396 *PCI_ISR = PCI_ISR_PSE | PCI_ISR_PFE | PCI_ISR_PPE | PCI_ISR_AHBE;
397
398 /*
399 * Set Initialize Complete in PCI Control Register: allow IXP4XX to
400 * respond to PCI configuration cycles. Specify that the AHB bus is
401 * operating in big endian mode. Set up byte lane swapping between
402 * little-endian PCI and the big-endian AHB bus
403 */
404 #ifdef __ARMEB__
405 *PCI_CSR = PCI_CSR_IC | PCI_CSR_ABE | PCI_CSR_PDS | PCI_CSR_ADS;
406 #else
407 *PCI_CSR = PCI_CSR_IC | PCI_CSR_ABE;
408 #endif
409
410 pr_debug("DONE\n");
411 }
412
ixp4xx_setup(int nr,struct pci_sys_data * sys)413 int ixp4xx_setup(int nr, struct pci_sys_data *sys)
414 {
415 struct resource *res;
416
417 if (nr >= 1)
418 return 0;
419
420 res = kcalloc(2, sizeof(*res), GFP_KERNEL);
421 if (res == NULL) {
422 /*
423 * If we're out of memory this early, something is wrong,
424 * so we might as well catch it here.
425 */
426 panic("PCI: unable to allocate resources?\n");
427 }
428
429 local_write_config(PCI_COMMAND, 2, PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY);
430
431 res[0].name = "PCI I/O Space";
432 res[0].start = 0x00000000;
433 res[0].end = 0x0000ffff;
434 res[0].flags = IORESOURCE_IO;
435
436 res[1].name = "PCI Memory Space";
437 res[1].start = PCIBIOS_MIN_MEM;
438 res[1].end = PCIBIOS_MAX_MEM;
439 res[1].flags = IORESOURCE_MEM;
440
441 request_resource(&ioport_resource, &res[0]);
442 request_resource(&iomem_resource, &res[1]);
443
444 pci_add_resource_offset(&sys->resources, &res[0], sys->io_offset);
445 pci_add_resource_offset(&sys->resources, &res[1], sys->mem_offset);
446
447 return 1;
448 }
449
450 EXPORT_SYMBOL(ixp4xx_pci_read);
451 EXPORT_SYMBOL(ixp4xx_pci_write);
452