xref: /openbmc/linux/arch/powerpc/sysdev/tsi108_pci.c (revision 2359ccdd)
1 /*
2  * Common routines for Tundra Semiconductor TSI108 host bridge.
3  *
4  * 2004-2005 (c) Tundra Semiconductor Corp.
5  * Author: Alex Bounine (alexandreb@tundra.com)
6  * Author: Roy Zang (tie-fei.zang@freescale.com)
7  * 	   Add pci interrupt router host
8  *
9  * This program is free software; you can redistribute it and/or modify it
10  * under the terms of the GNU General Public License as published by the Free
11  * Software Foundation; either version 2 of the License, or (at your option)
12  * any later version.
13  *
14  * This program is distributed in the hope that it will be useful, but WITHOUT
15  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
16  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
17  * more details.
18  *
19  * You should have received a copy of the GNU General Public License along with
20  * this program; if not, write to the Free Software Foundation, Inc., 59
21  * Temple Place - Suite 330, Boston, MA  02111-1307, USA.
22  */
23 
24 #include <linux/kernel.h>
25 #include <linux/init.h>
26 #include <linux/pci.h>
27 #include <linux/irq.h>
28 #include <linux/interrupt.h>
29 
30 #include <asm/byteorder.h>
31 #include <asm/io.h>
32 #include <asm/irq.h>
33 #include <linux/uaccess.h>
34 #include <asm/machdep.h>
35 #include <asm/pci-bridge.h>
36 #include <asm/tsi108.h>
37 #include <asm/tsi108_pci.h>
38 #include <asm/tsi108_irq.h>
39 #include <asm/prom.h>
40 
41 #undef DEBUG
42 #ifdef DEBUG
43 #define DBG(x...) printk(x)
44 #else
45 #define DBG(x...)
46 #endif
47 
48 #define tsi_mk_config_addr(bus, devfunc, offset) \
49 	((((bus)<<16) | ((devfunc)<<8) | (offset & 0xfc)) + tsi108_pci_cfg_base)
50 
51 u32 tsi108_pci_cfg_base;
52 static u32 tsi108_pci_cfg_phys;
53 u32 tsi108_csr_vir_base;
54 static struct irq_domain *pci_irq_host;
55 
56 extern u32 get_vir_csrbase(void);
57 extern u32 tsi108_read_reg(u32 reg_offset);
58 extern void tsi108_write_reg(u32 reg_offset, u32 val);
59 
60 int
61 tsi108_direct_write_config(struct pci_bus *bus, unsigned int devfunc,
62 			   int offset, int len, u32 val)
63 {
64 	volatile unsigned char *cfg_addr;
65 	struct pci_controller *hose = pci_bus_to_host(bus);
66 
67 	if (ppc_md.pci_exclude_device)
68 		if (ppc_md.pci_exclude_device(hose, bus->number, devfunc))
69 			return PCIBIOS_DEVICE_NOT_FOUND;
70 
71 	cfg_addr = (unsigned char *)(tsi_mk_config_addr(bus->number,
72 							devfunc, offset) |
73 							(offset & 0x03));
74 
75 #ifdef DEBUG
76 	printk("PCI CFG write : ");
77 	printk("%d:0x%x:0x%x ", bus->number, devfunc, offset);
78 	printk("%d ADDR=0x%08x ", len, (uint) cfg_addr);
79 	printk("data = 0x%08x\n", val);
80 #endif
81 
82 	switch (len) {
83 	case 1:
84 		out_8((u8 *) cfg_addr, val);
85 		break;
86 	case 2:
87 		out_le16((u16 *) cfg_addr, val);
88 		break;
89 	default:
90 		out_le32((u32 *) cfg_addr, val);
91 		break;
92 	}
93 
94 	return PCIBIOS_SUCCESSFUL;
95 }
96 
97 void tsi108_clear_pci_error(u32 pci_cfg_base)
98 {
99 	u32 err_stat, err_addr, pci_stat;
100 
101 	/*
102 	 * Quietly clear PB and PCI error flags set as result
103 	 * of PCI/X configuration read requests.
104 	 */
105 
106 	/* Read PB Error Log Registers */
107 
108 	err_stat = tsi108_read_reg(TSI108_PB_OFFSET + TSI108_PB_ERRCS);
109 	err_addr = tsi108_read_reg(TSI108_PB_OFFSET + TSI108_PB_AERR);
110 
111 	if (err_stat & TSI108_PB_ERRCS_ES) {
112 		/* Clear error flag */
113 		tsi108_write_reg(TSI108_PB_OFFSET + TSI108_PB_ERRCS,
114 				 TSI108_PB_ERRCS_ES);
115 
116 		/* Clear read error reported in PB_ISR */
117 		tsi108_write_reg(TSI108_PB_OFFSET + TSI108_PB_ISR,
118 				 TSI108_PB_ISR_PBS_RD_ERR);
119 
120 		/* Clear PCI/X bus cfg errors if applicable */
121 		if ((err_addr & 0xFF000000) == pci_cfg_base) {
122 			pci_stat =
123 			    tsi108_read_reg(TSI108_PCI_OFFSET + TSI108_PCI_CSR);
124 			tsi108_write_reg(TSI108_PCI_OFFSET + TSI108_PCI_CSR,
125 					 pci_stat);
126 		}
127 	}
128 
129 	return;
130 }
131 
132 #define __tsi108_read_pci_config(x, addr, op)		\
133 	__asm__ __volatile__(				\
134 		"	"op" %0,0,%1\n"		\
135 		"1:	eieio\n"			\
136 		"2:\n"					\
137 		".section .fixup,\"ax\"\n"		\
138 		"3:	li %0,-1\n"			\
139 		"	b 2b\n"				\
140 		".previous\n"				\
141 		EX_TABLE(1b, 3b)			\
142 		: "=r"(x) : "r"(addr))
143 
144 int
145 tsi108_direct_read_config(struct pci_bus *bus, unsigned int devfn, int offset,
146 			  int len, u32 * val)
147 {
148 	volatile unsigned char *cfg_addr;
149 	struct pci_controller *hose = pci_bus_to_host(bus);
150 	u32 temp;
151 
152 	if (ppc_md.pci_exclude_device)
153 		if (ppc_md.pci_exclude_device(hose, bus->number, devfn))
154 			return PCIBIOS_DEVICE_NOT_FOUND;
155 
156 	cfg_addr = (unsigned char *)(tsi_mk_config_addr(bus->number,
157 							devfn,
158 							offset) | (offset &
159 								   0x03));
160 
161 	switch (len) {
162 	case 1:
163 		__tsi108_read_pci_config(temp, cfg_addr, "lbzx");
164 		break;
165 	case 2:
166 		__tsi108_read_pci_config(temp, cfg_addr, "lhbrx");
167 		break;
168 	default:
169 		__tsi108_read_pci_config(temp, cfg_addr, "lwbrx");
170 		break;
171 	}
172 
173 	*val = temp;
174 
175 #ifdef DEBUG
176 	if ((0xFFFFFFFF != temp) && (0xFFFF != temp) && (0xFF != temp)) {
177 		printk("PCI CFG read : ");
178 		printk("%d:0x%x:0x%x ", bus->number, devfn, offset);
179 		printk("%d ADDR=0x%08x ", len, (uint) cfg_addr);
180 		printk("data = 0x%x\n", *val);
181 	}
182 #endif
183 	return PCIBIOS_SUCCESSFUL;
184 }
185 
186 void tsi108_clear_pci_cfg_error(void)
187 {
188 	tsi108_clear_pci_error(tsi108_pci_cfg_phys);
189 }
190 
191 static struct pci_ops tsi108_direct_pci_ops = {
192 	.read = tsi108_direct_read_config,
193 	.write = tsi108_direct_write_config,
194 };
195 
196 int __init tsi108_setup_pci(struct device_node *dev, u32 cfg_phys, int primary)
197 {
198 	int len;
199 	struct pci_controller *hose;
200 	struct resource rsrc;
201 	const int *bus_range;
202 	int has_address = 0;
203 
204 	/* PCI Config mapping */
205 	tsi108_pci_cfg_base = (u32)ioremap(cfg_phys, TSI108_PCI_CFG_SIZE);
206 	tsi108_pci_cfg_phys = cfg_phys;
207 	DBG("TSI_PCI: %s tsi108_pci_cfg_base=0x%x\n", __func__,
208 	    tsi108_pci_cfg_base);
209 
210 	/* Fetch host bridge registers address */
211 	has_address = (of_address_to_resource(dev, 0, &rsrc) == 0);
212 
213 	/* Get bus range if any */
214 	bus_range = of_get_property(dev, "bus-range", &len);
215 	if (bus_range == NULL || len < 2 * sizeof(int)) {
216 		printk(KERN_WARNING "Can't get bus-range for %pOF, assume"
217 		       " bus 0\n", dev);
218 	}
219 
220 	hose = pcibios_alloc_controller(dev);
221 
222 	if (!hose) {
223 		printk("PCI Host bridge init failed\n");
224 		return -ENOMEM;
225 	}
226 
227 	hose->first_busno = bus_range ? bus_range[0] : 0;
228 	hose->last_busno = bus_range ? bus_range[1] : 0xff;
229 
230 	(hose)->ops = &tsi108_direct_pci_ops;
231 
232 	printk(KERN_INFO "Found tsi108 PCI host bridge at 0x%08x. "
233 	       "Firmware bus number: %d->%d\n",
234 	       rsrc.start, hose->first_busno, hose->last_busno);
235 
236 	/* Interpret the "ranges" property */
237 	/* This also maps the I/O region and sets isa_io/mem_base */
238 	pci_process_bridge_OF_ranges(hose, dev, primary);
239 	return 0;
240 }
241 
242 /*
243  * Low level utility functions
244  */
245 
246 static void tsi108_pci_int_mask(u_int irq)
247 {
248 	u_int irp_cfg;
249 	int int_line = (irq - IRQ_PCI_INTAD_BASE);
250 
251 	irp_cfg = tsi108_read_reg(TSI108_PCI_OFFSET + TSI108_PCI_IRP_CFG_CTL);
252 	mb();
253 	irp_cfg |= (1 << int_line);	/* INTx_DIR = output */
254 	irp_cfg &= ~(3 << (8 + (int_line * 2)));	/* INTx_TYPE = unused */
255 	tsi108_write_reg(TSI108_PCI_OFFSET + TSI108_PCI_IRP_CFG_CTL, irp_cfg);
256 	mb();
257 	irp_cfg = tsi108_read_reg(TSI108_PCI_OFFSET + TSI108_PCI_IRP_CFG_CTL);
258 }
259 
260 static void tsi108_pci_int_unmask(u_int irq)
261 {
262 	u_int irp_cfg;
263 	int int_line = (irq - IRQ_PCI_INTAD_BASE);
264 
265 	irp_cfg = tsi108_read_reg(TSI108_PCI_OFFSET + TSI108_PCI_IRP_CFG_CTL);
266 	mb();
267 	irp_cfg &= ~(1 << int_line);
268 	irp_cfg |= (3 << (8 + (int_line * 2)));
269 	tsi108_write_reg(TSI108_PCI_OFFSET + TSI108_PCI_IRP_CFG_CTL, irp_cfg);
270 	mb();
271 }
272 
273 static void init_pci_source(void)
274 {
275 	tsi108_write_reg(TSI108_PCI_OFFSET + TSI108_PCI_IRP_CFG_CTL,
276 			0x0000ff00);
277 	tsi108_write_reg(TSI108_PCI_OFFSET + TSI108_PCI_IRP_ENABLE,
278 			TSI108_PCI_IRP_ENABLE_P_INT);
279 	mb();
280 }
281 
282 static inline unsigned int get_pci_source(void)
283 {
284 	u_int temp = 0;
285 	int irq = -1;
286 	int i;
287 	u_int pci_irp_stat;
288 	static int mask = 0;
289 
290 	/* Read PCI/X block interrupt status register */
291 	pci_irp_stat = tsi108_read_reg(TSI108_PCI_OFFSET + TSI108_PCI_IRP_STAT);
292 	mb();
293 
294 	if (pci_irp_stat & TSI108_PCI_IRP_STAT_P_INT) {
295 		/* Process Interrupt from PCI bus INTA# - INTD# lines */
296 		temp =
297 		    tsi108_read_reg(TSI108_PCI_OFFSET +
298 				    TSI108_PCI_IRP_INTAD) & 0xf;
299 		mb();
300 		for (i = 0; i < 4; i++, mask++) {
301 			if (temp & (1 << mask % 4)) {
302 				irq = IRQ_PCI_INTA + mask % 4;
303 				mask++;
304 				break;
305 			}
306 		}
307 
308 		/* Disable interrupts from PCI block */
309 		temp = tsi108_read_reg(TSI108_PCI_OFFSET + TSI108_PCI_IRP_ENABLE);
310 		tsi108_write_reg(TSI108_PCI_OFFSET + TSI108_PCI_IRP_ENABLE,
311 				temp & ~TSI108_PCI_IRP_ENABLE_P_INT);
312 		mb();
313 		(void)tsi108_read_reg(TSI108_PCI_OFFSET + TSI108_PCI_IRP_ENABLE);
314 		mb();
315 	}
316 #ifdef DEBUG
317 	else {
318 		printk("TSI108_PIC: error in TSI108_PCI_IRP_STAT\n");
319 		pci_irp_stat =
320 		    tsi108_read_reg(TSI108_PCI_OFFSET + TSI108_PCI_IRP_STAT);
321 		temp =
322 		    tsi108_read_reg(TSI108_PCI_OFFSET + TSI108_PCI_IRP_INTAD);
323 		mb();
324 		printk(">> stat=0x%08x intad=0x%08x ", pci_irp_stat, temp);
325 		temp =
326 		    tsi108_read_reg(TSI108_PCI_OFFSET + TSI108_PCI_IRP_CFG_CTL);
327 		mb();
328 		printk("cfg_ctl=0x%08x ", temp);
329 		temp =
330 		    tsi108_read_reg(TSI108_PCI_OFFSET + TSI108_PCI_IRP_ENABLE);
331 		mb();
332 		printk("irp_enable=0x%08x\n", temp);
333 	}
334 #endif	/* end of DEBUG */
335 
336 	return irq;
337 }
338 
339 
340 /*
341  * Linux descriptor level callbacks
342  */
343 
344 static void tsi108_pci_irq_unmask(struct irq_data *d)
345 {
346 	tsi108_pci_int_unmask(d->irq);
347 
348 	/* Enable interrupts from PCI block */
349 	tsi108_write_reg(TSI108_PCI_OFFSET + TSI108_PCI_IRP_ENABLE,
350 			 tsi108_read_reg(TSI108_PCI_OFFSET +
351 					 TSI108_PCI_IRP_ENABLE) |
352 			 TSI108_PCI_IRP_ENABLE_P_INT);
353 	mb();
354 }
355 
356 static void tsi108_pci_irq_mask(struct irq_data *d)
357 {
358 	tsi108_pci_int_mask(d->irq);
359 }
360 
361 static void tsi108_pci_irq_ack(struct irq_data *d)
362 {
363 	tsi108_pci_int_mask(d->irq);
364 }
365 
366 /*
367  * Interrupt controller descriptor for cascaded PCI interrupt controller.
368  */
369 
370 static struct irq_chip tsi108_pci_irq = {
371 	.name = "tsi108_PCI_int",
372 	.irq_mask = tsi108_pci_irq_mask,
373 	.irq_ack = tsi108_pci_irq_ack,
374 	.irq_unmask = tsi108_pci_irq_unmask,
375 };
376 
377 static int pci_irq_host_xlate(struct irq_domain *h, struct device_node *ct,
378 			    const u32 *intspec, unsigned int intsize,
379 			    irq_hw_number_t *out_hwirq, unsigned int *out_flags)
380 {
381 	*out_hwirq = intspec[0];
382 	*out_flags = IRQ_TYPE_LEVEL_HIGH;
383 	return 0;
384 }
385 
386 static int pci_irq_host_map(struct irq_domain *h, unsigned int virq,
387 			  irq_hw_number_t hw)
388 {	unsigned int irq;
389 	DBG("%s(%d, 0x%lx)\n", __func__, virq, hw);
390 	if ((virq >= 1) && (virq <= 4)){
391 		irq = virq + IRQ_PCI_INTAD_BASE - 1;
392 		irq_set_status_flags(irq, IRQ_LEVEL);
393 		irq_set_chip(irq, &tsi108_pci_irq);
394 	}
395 	return 0;
396 }
397 
398 static const struct irq_domain_ops pci_irq_domain_ops = {
399 	.map = pci_irq_host_map,
400 	.xlate = pci_irq_host_xlate,
401 };
402 
403 /*
404  * Exported functions
405  */
406 
407 /*
408  * The Tsi108 PCI interrupts initialization routine.
409  *
410  * The INTA# - INTD# interrupts on the PCI bus are reported by the PCI block
411  * to the MPIC using single interrupt source (IRQ_TSI108_PCI). Therefore the
412  * PCI block has to be treated as a cascaded interrupt controller connected
413  * to the MPIC.
414  */
415 
416 void __init tsi108_pci_int_init(struct device_node *node)
417 {
418 	DBG("Tsi108_pci_int_init: initializing PCI interrupts\n");
419 
420 	pci_irq_host = irq_domain_add_legacy_isa(node, &pci_irq_domain_ops, NULL);
421 	if (pci_irq_host == NULL) {
422 		printk(KERN_ERR "pci_irq_host: failed to allocate irq domain!\n");
423 		return;
424 	}
425 
426 	init_pci_source();
427 }
428 
429 void tsi108_irq_cascade(struct irq_desc *desc)
430 {
431 	struct irq_chip *chip = irq_desc_get_chip(desc);
432 	unsigned int cascade_irq = get_pci_source();
433 
434 	if (cascade_irq)
435 		generic_handle_irq(cascade_irq);
436 
437 	chip->irq_eoi(&desc->irq_data);
438 }
439