xref: /linux/arch/mips/pci/pci-ar71xx.c (revision 827634added7f38b7d724cab1dccdb2b004c13c3)
1 /*
2  *  Atheros AR71xx PCI host controller driver
3  *
4  *  Copyright (C) 2008-2011 Gabor Juhos <juhosg@openwrt.org>
5  *  Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
6  *
7  *  Parts of this file are based on Atheros' 2.6.15 BSP
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 version 2 as published
11  *  by the Free Software Foundation.
12  */
13 
14 #include <linux/resource.h>
15 #include <linux/types.h>
16 #include <linux/delay.h>
17 #include <linux/bitops.h>
18 #include <linux/pci.h>
19 #include <linux/pci_regs.h>
20 #include <linux/interrupt.h>
21 #include <linux/module.h>
22 #include <linux/platform_device.h>
23 
24 #include <asm/mach-ath79/ar71xx_regs.h>
25 #include <asm/mach-ath79/ath79.h>
26 
27 #define AR71XX_PCI_REG_CRP_AD_CBE	0x00
28 #define AR71XX_PCI_REG_CRP_WRDATA	0x04
29 #define AR71XX_PCI_REG_CRP_RDDATA	0x08
30 #define AR71XX_PCI_REG_CFG_AD		0x0c
31 #define AR71XX_PCI_REG_CFG_CBE		0x10
32 #define AR71XX_PCI_REG_CFG_WRDATA	0x14
33 #define AR71XX_PCI_REG_CFG_RDDATA	0x18
34 #define AR71XX_PCI_REG_PCI_ERR		0x1c
35 #define AR71XX_PCI_REG_PCI_ERR_ADDR	0x20
36 #define AR71XX_PCI_REG_AHB_ERR		0x24
37 #define AR71XX_PCI_REG_AHB_ERR_ADDR	0x28
38 
39 #define AR71XX_PCI_CRP_CMD_WRITE	0x00010000
40 #define AR71XX_PCI_CRP_CMD_READ		0x00000000
41 #define AR71XX_PCI_CFG_CMD_READ		0x0000000a
42 #define AR71XX_PCI_CFG_CMD_WRITE	0x0000000b
43 
44 #define AR71XX_PCI_INT_CORE		BIT(4)
45 #define AR71XX_PCI_INT_DEV2		BIT(2)
46 #define AR71XX_PCI_INT_DEV1		BIT(1)
47 #define AR71XX_PCI_INT_DEV0		BIT(0)
48 
49 #define AR71XX_PCI_IRQ_COUNT		5
50 
51 struct ar71xx_pci_controller {
52 	void __iomem *cfg_base;
53 	int irq;
54 	int irq_base;
55 	struct pci_controller pci_ctrl;
56 	struct resource io_res;
57 	struct resource mem_res;
58 };
59 
60 /* Byte lane enable bits */
61 static const u8 ar71xx_pci_ble_table[4][4] = {
62 	{0x0, 0xf, 0xf, 0xf},
63 	{0xe, 0xd, 0xb, 0x7},
64 	{0xc, 0xf, 0x3, 0xf},
65 	{0xf, 0xf, 0xf, 0xf},
66 };
67 
68 static const u32 ar71xx_pci_read_mask[8] = {
69 	0, 0xff, 0xffff, 0, 0xffffffff, 0, 0, 0
70 };
71 
72 static inline u32 ar71xx_pci_get_ble(int where, int size, int local)
73 {
74 	u32 t;
75 
76 	t = ar71xx_pci_ble_table[size & 3][where & 3];
77 	BUG_ON(t == 0xf);
78 	t <<= (local) ? 20 : 4;
79 
80 	return t;
81 }
82 
83 static inline u32 ar71xx_pci_bus_addr(struct pci_bus *bus, unsigned int devfn,
84 				      int where)
85 {
86 	u32 ret;
87 
88 	if (!bus->number) {
89 		/* type 0 */
90 		ret = (1 << PCI_SLOT(devfn)) | (PCI_FUNC(devfn) << 8) |
91 		      (where & ~3);
92 	} else {
93 		/* type 1 */
94 		ret = (bus->number << 16) | (PCI_SLOT(devfn) << 11) |
95 		      (PCI_FUNC(devfn) << 8) | (where & ~3) | 1;
96 	}
97 
98 	return ret;
99 }
100 
101 static inline struct ar71xx_pci_controller *
102 pci_bus_to_ar71xx_controller(struct pci_bus *bus)
103 {
104 	struct pci_controller *hose;
105 
106 	hose = (struct pci_controller *) bus->sysdata;
107 	return container_of(hose, struct ar71xx_pci_controller, pci_ctrl);
108 }
109 
110 static int ar71xx_pci_check_error(struct ar71xx_pci_controller *apc, int quiet)
111 {
112 	void __iomem *base = apc->cfg_base;
113 	u32 pci_err;
114 	u32 ahb_err;
115 
116 	pci_err = __raw_readl(base + AR71XX_PCI_REG_PCI_ERR) & 3;
117 	if (pci_err) {
118 		if (!quiet) {
119 			u32 addr;
120 
121 			addr = __raw_readl(base + AR71XX_PCI_REG_PCI_ERR_ADDR);
122 			pr_crit("ar71xx: %s bus error %d at addr 0x%x\n",
123 				"PCI", pci_err, addr);
124 		}
125 
126 		/* clear PCI error status */
127 		__raw_writel(pci_err, base + AR71XX_PCI_REG_PCI_ERR);
128 	}
129 
130 	ahb_err = __raw_readl(base + AR71XX_PCI_REG_AHB_ERR) & 1;
131 	if (ahb_err) {
132 		if (!quiet) {
133 			u32 addr;
134 
135 			addr = __raw_readl(base + AR71XX_PCI_REG_AHB_ERR_ADDR);
136 			pr_crit("ar71xx: %s bus error %d at addr 0x%x\n",
137 				"AHB", ahb_err, addr);
138 		}
139 
140 		/* clear AHB error status */
141 		__raw_writel(ahb_err, base + AR71XX_PCI_REG_AHB_ERR);
142 	}
143 
144 	return !!(ahb_err | pci_err);
145 }
146 
147 static inline void ar71xx_pci_local_write(struct ar71xx_pci_controller *apc,
148 					  int where, int size, u32 value)
149 {
150 	void __iomem *base = apc->cfg_base;
151 	u32 ad_cbe;
152 
153 	value = value << (8 * (where & 3));
154 
155 	ad_cbe = AR71XX_PCI_CRP_CMD_WRITE | (where & ~3);
156 	ad_cbe |= ar71xx_pci_get_ble(where, size, 1);
157 
158 	__raw_writel(ad_cbe, base + AR71XX_PCI_REG_CRP_AD_CBE);
159 	__raw_writel(value, base + AR71XX_PCI_REG_CRP_WRDATA);
160 }
161 
162 static inline int ar71xx_pci_set_cfgaddr(struct pci_bus *bus,
163 					 unsigned int devfn,
164 					 int where, int size, u32 cmd)
165 {
166 	struct ar71xx_pci_controller *apc = pci_bus_to_ar71xx_controller(bus);
167 	void __iomem *base = apc->cfg_base;
168 	u32 addr;
169 
170 	addr = ar71xx_pci_bus_addr(bus, devfn, where);
171 
172 	__raw_writel(addr, base + AR71XX_PCI_REG_CFG_AD);
173 	__raw_writel(cmd | ar71xx_pci_get_ble(where, size, 0),
174 		     base + AR71XX_PCI_REG_CFG_CBE);
175 
176 	return ar71xx_pci_check_error(apc, 1);
177 }
178 
179 static int ar71xx_pci_read_config(struct pci_bus *bus, unsigned int devfn,
180 				  int where, int size, u32 *value)
181 {
182 	struct ar71xx_pci_controller *apc = pci_bus_to_ar71xx_controller(bus);
183 	void __iomem *base = apc->cfg_base;
184 	u32 data;
185 	int err;
186 	int ret;
187 
188 	ret = PCIBIOS_SUCCESSFUL;
189 	data = ~0;
190 
191 	err = ar71xx_pci_set_cfgaddr(bus, devfn, where, size,
192 				     AR71XX_PCI_CFG_CMD_READ);
193 	if (err)
194 		ret = PCIBIOS_DEVICE_NOT_FOUND;
195 	else
196 		data = __raw_readl(base + AR71XX_PCI_REG_CFG_RDDATA);
197 
198 	*value = (data >> (8 * (where & 3))) & ar71xx_pci_read_mask[size & 7];
199 
200 	return ret;
201 }
202 
203 static int ar71xx_pci_write_config(struct pci_bus *bus, unsigned int devfn,
204 				   int where, int size, u32 value)
205 {
206 	struct ar71xx_pci_controller *apc = pci_bus_to_ar71xx_controller(bus);
207 	void __iomem *base = apc->cfg_base;
208 	int err;
209 	int ret;
210 
211 	value = value << (8 * (where & 3));
212 	ret = PCIBIOS_SUCCESSFUL;
213 
214 	err = ar71xx_pci_set_cfgaddr(bus, devfn, where, size,
215 				     AR71XX_PCI_CFG_CMD_WRITE);
216 	if (err)
217 		ret = PCIBIOS_DEVICE_NOT_FOUND;
218 	else
219 		__raw_writel(value, base + AR71XX_PCI_REG_CFG_WRDATA);
220 
221 	return ret;
222 }
223 
224 static struct pci_ops ar71xx_pci_ops = {
225 	.read	= ar71xx_pci_read_config,
226 	.write	= ar71xx_pci_write_config,
227 };
228 
229 static void ar71xx_pci_irq_handler(unsigned int irq, struct irq_desc *desc)
230 {
231 	struct ar71xx_pci_controller *apc;
232 	void __iomem *base = ath79_reset_base;
233 	u32 pending;
234 
235 	apc = irq_get_handler_data(irq);
236 
237 	pending = __raw_readl(base + AR71XX_RESET_REG_PCI_INT_STATUS) &
238 		  __raw_readl(base + AR71XX_RESET_REG_PCI_INT_ENABLE);
239 
240 	if (pending & AR71XX_PCI_INT_DEV0)
241 		generic_handle_irq(apc->irq_base + 0);
242 
243 	else if (pending & AR71XX_PCI_INT_DEV1)
244 		generic_handle_irq(apc->irq_base + 1);
245 
246 	else if (pending & AR71XX_PCI_INT_DEV2)
247 		generic_handle_irq(apc->irq_base + 2);
248 
249 	else if (pending & AR71XX_PCI_INT_CORE)
250 		generic_handle_irq(apc->irq_base + 4);
251 
252 	else
253 		spurious_interrupt();
254 }
255 
256 static void ar71xx_pci_irq_unmask(struct irq_data *d)
257 {
258 	struct ar71xx_pci_controller *apc;
259 	unsigned int irq;
260 	void __iomem *base = ath79_reset_base;
261 	u32 t;
262 
263 	apc = irq_data_get_irq_chip_data(d);
264 	irq = d->irq - apc->irq_base;
265 
266 	t = __raw_readl(base + AR71XX_RESET_REG_PCI_INT_ENABLE);
267 	__raw_writel(t | (1 << irq), base + AR71XX_RESET_REG_PCI_INT_ENABLE);
268 
269 	/* flush write */
270 	__raw_readl(base + AR71XX_RESET_REG_PCI_INT_ENABLE);
271 }
272 
273 static void ar71xx_pci_irq_mask(struct irq_data *d)
274 {
275 	struct ar71xx_pci_controller *apc;
276 	unsigned int irq;
277 	void __iomem *base = ath79_reset_base;
278 	u32 t;
279 
280 	apc = irq_data_get_irq_chip_data(d);
281 	irq = d->irq - apc->irq_base;
282 
283 	t = __raw_readl(base + AR71XX_RESET_REG_PCI_INT_ENABLE);
284 	__raw_writel(t & ~(1 << irq), base + AR71XX_RESET_REG_PCI_INT_ENABLE);
285 
286 	/* flush write */
287 	__raw_readl(base + AR71XX_RESET_REG_PCI_INT_ENABLE);
288 }
289 
290 static struct irq_chip ar71xx_pci_irq_chip = {
291 	.name		= "AR71XX PCI",
292 	.irq_mask	= ar71xx_pci_irq_mask,
293 	.irq_unmask	= ar71xx_pci_irq_unmask,
294 	.irq_mask_ack	= ar71xx_pci_irq_mask,
295 };
296 
297 static void ar71xx_pci_irq_init(struct ar71xx_pci_controller *apc)
298 {
299 	void __iomem *base = ath79_reset_base;
300 	int i;
301 
302 	__raw_writel(0, base + AR71XX_RESET_REG_PCI_INT_ENABLE);
303 	__raw_writel(0, base + AR71XX_RESET_REG_PCI_INT_STATUS);
304 
305 	BUILD_BUG_ON(ATH79_PCI_IRQ_COUNT < AR71XX_PCI_IRQ_COUNT);
306 
307 	apc->irq_base = ATH79_PCI_IRQ_BASE;
308 	for (i = apc->irq_base;
309 	     i < apc->irq_base + AR71XX_PCI_IRQ_COUNT; i++) {
310 		irq_set_chip_and_handler(i, &ar71xx_pci_irq_chip,
311 					 handle_level_irq);
312 		irq_set_chip_data(i, apc);
313 	}
314 
315 	irq_set_handler_data(apc->irq, apc);
316 	irq_set_chained_handler(apc->irq, ar71xx_pci_irq_handler);
317 }
318 
319 static void ar71xx_pci_reset(void)
320 {
321 	void __iomem *ddr_base = ath79_ddr_base;
322 
323 	ath79_device_reset_set(AR71XX_RESET_PCI_BUS | AR71XX_RESET_PCI_CORE);
324 	mdelay(100);
325 
326 	ath79_device_reset_clear(AR71XX_RESET_PCI_BUS | AR71XX_RESET_PCI_CORE);
327 	mdelay(100);
328 
329 	__raw_writel(AR71XX_PCI_WIN0_OFFS, ddr_base + AR71XX_DDR_REG_PCI_WIN0);
330 	__raw_writel(AR71XX_PCI_WIN1_OFFS, ddr_base + AR71XX_DDR_REG_PCI_WIN1);
331 	__raw_writel(AR71XX_PCI_WIN2_OFFS, ddr_base + AR71XX_DDR_REG_PCI_WIN2);
332 	__raw_writel(AR71XX_PCI_WIN3_OFFS, ddr_base + AR71XX_DDR_REG_PCI_WIN3);
333 	__raw_writel(AR71XX_PCI_WIN4_OFFS, ddr_base + AR71XX_DDR_REG_PCI_WIN4);
334 	__raw_writel(AR71XX_PCI_WIN5_OFFS, ddr_base + AR71XX_DDR_REG_PCI_WIN5);
335 	__raw_writel(AR71XX_PCI_WIN6_OFFS, ddr_base + AR71XX_DDR_REG_PCI_WIN6);
336 	__raw_writel(AR71XX_PCI_WIN7_OFFS, ddr_base + AR71XX_DDR_REG_PCI_WIN7);
337 
338 	mdelay(100);
339 }
340 
341 static int ar71xx_pci_probe(struct platform_device *pdev)
342 {
343 	struct ar71xx_pci_controller *apc;
344 	struct resource *res;
345 	u32 t;
346 
347 	apc = devm_kzalloc(&pdev->dev, sizeof(struct ar71xx_pci_controller),
348 			   GFP_KERNEL);
349 	if (!apc)
350 		return -ENOMEM;
351 
352 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cfg_base");
353 	apc->cfg_base = devm_ioremap_resource(&pdev->dev, res);
354 	if (IS_ERR(apc->cfg_base))
355 		return PTR_ERR(apc->cfg_base);
356 
357 	apc->irq = platform_get_irq(pdev, 0);
358 	if (apc->irq < 0)
359 		return -EINVAL;
360 
361 	res = platform_get_resource_byname(pdev, IORESOURCE_IO, "io_base");
362 	if (!res)
363 		return -EINVAL;
364 
365 	apc->io_res.parent = res;
366 	apc->io_res.name = "PCI IO space";
367 	apc->io_res.start = res->start;
368 	apc->io_res.end = res->end;
369 	apc->io_res.flags = IORESOURCE_IO;
370 
371 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mem_base");
372 	if (!res)
373 		return -EINVAL;
374 
375 	apc->mem_res.parent = res;
376 	apc->mem_res.name = "PCI memory space";
377 	apc->mem_res.start = res->start;
378 	apc->mem_res.end = res->end;
379 	apc->mem_res.flags = IORESOURCE_MEM;
380 
381 	ar71xx_pci_reset();
382 
383 	/* setup COMMAND register */
384 	t = PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER | PCI_COMMAND_INVALIDATE
385 	  | PCI_COMMAND_PARITY | PCI_COMMAND_SERR | PCI_COMMAND_FAST_BACK;
386 	ar71xx_pci_local_write(apc, PCI_COMMAND, 4, t);
387 
388 	/* clear bus errors */
389 	ar71xx_pci_check_error(apc, 1);
390 
391 	ar71xx_pci_irq_init(apc);
392 
393 	apc->pci_ctrl.pci_ops = &ar71xx_pci_ops;
394 	apc->pci_ctrl.mem_resource = &apc->mem_res;
395 	apc->pci_ctrl.io_resource = &apc->io_res;
396 
397 	register_pci_controller(&apc->pci_ctrl);
398 
399 	return 0;
400 }
401 
402 static struct platform_driver ar71xx_pci_driver = {
403 	.probe = ar71xx_pci_probe,
404 	.driver = {
405 		.name = "ar71xx-pci",
406 	},
407 };
408 
409 static int __init ar71xx_pci_init(void)
410 {
411 	return platform_driver_register(&ar71xx_pci_driver);
412 }
413 
414 postcore_initcall(ar71xx_pci_init);
415