1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Atheros AR71xx PCI host controller driver
4 *
5 * Copyright (C) 2008-2011 Gabor Juhos <juhosg@openwrt.org>
6 * Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
7 *
8 * Parts of this file are based on Atheros' 2.6.15 BSP
9 */
10
11 #include <linux/resource.h>
12 #include <linux/types.h>
13 #include <linux/delay.h>
14 #include <linux/bitops.h>
15 #include <linux/pci.h>
16 #include <linux/pci_regs.h>
17 #include <linux/interrupt.h>
18 #include <linux/init.h>
19 #include <linux/platform_device.h>
20
21 #include <asm/mach-ath79/ar71xx_regs.h>
22 #include <asm/mach-ath79/ath79.h>
23
24 #define AR71XX_PCI_REG_CRP_AD_CBE 0x00
25 #define AR71XX_PCI_REG_CRP_WRDATA 0x04
26 #define AR71XX_PCI_REG_CRP_RDDATA 0x08
27 #define AR71XX_PCI_REG_CFG_AD 0x0c
28 #define AR71XX_PCI_REG_CFG_CBE 0x10
29 #define AR71XX_PCI_REG_CFG_WRDATA 0x14
30 #define AR71XX_PCI_REG_CFG_RDDATA 0x18
31 #define AR71XX_PCI_REG_PCI_ERR 0x1c
32 #define AR71XX_PCI_REG_PCI_ERR_ADDR 0x20
33 #define AR71XX_PCI_REG_AHB_ERR 0x24
34 #define AR71XX_PCI_REG_AHB_ERR_ADDR 0x28
35
36 #define AR71XX_PCI_CRP_CMD_WRITE 0x00010000
37 #define AR71XX_PCI_CRP_CMD_READ 0x00000000
38 #define AR71XX_PCI_CFG_CMD_READ 0x0000000a
39 #define AR71XX_PCI_CFG_CMD_WRITE 0x0000000b
40
41 #define AR71XX_PCI_INT_CORE BIT(4)
42 #define AR71XX_PCI_INT_DEV2 BIT(2)
43 #define AR71XX_PCI_INT_DEV1 BIT(1)
44 #define AR71XX_PCI_INT_DEV0 BIT(0)
45
46 #define AR71XX_PCI_IRQ_COUNT 5
47
48 struct ar71xx_pci_controller {
49 void __iomem *cfg_base;
50 int irq;
51 int irq_base;
52 struct pci_controller pci_ctrl;
53 struct resource io_res;
54 struct resource mem_res;
55 };
56
57 /* Byte lane enable bits */
58 static const u8 ar71xx_pci_ble_table[4][4] = {
59 {0x0, 0xf, 0xf, 0xf},
60 {0xe, 0xd, 0xb, 0x7},
61 {0xc, 0xf, 0x3, 0xf},
62 {0xf, 0xf, 0xf, 0xf},
63 };
64
65 static const u32 ar71xx_pci_read_mask[8] = {
66 0, 0xff, 0xffff, 0, 0xffffffff, 0, 0, 0
67 };
68
69 static inline u32 ar71xx_pci_get_ble(int where, int size, int local)
70 {
71 u32 t;
72
73 t = ar71xx_pci_ble_table[size & 3][where & 3];
74 BUG_ON(t == 0xf);
75 t <<= (local) ? 20 : 4;
76
77 return t;
78 }
79
80 static inline u32 ar71xx_pci_bus_addr(struct pci_bus *bus, unsigned int devfn,
81 int where)
82 {
83 u32 ret;
84
85 if (!bus->number) {
86 /* type 0 */
87 ret = (1 << PCI_SLOT(devfn)) | (PCI_FUNC(devfn) << 8) |
88 (where & ~3);
89 } else {
90 /* type 1 */
91 ret = (bus->number << 16) | (PCI_SLOT(devfn) << 11) |
92 (PCI_FUNC(devfn) << 8) | (where & ~3) | 1;
93 }
94
95 return ret;
96 }
97
98 static inline struct ar71xx_pci_controller *
99 pci_bus_to_ar71xx_controller(struct pci_bus *bus)
100 {
101 struct pci_controller *hose;
102
103 hose = (struct pci_controller *) bus->sysdata;
104 return container_of(hose, struct ar71xx_pci_controller, pci_ctrl);
105 }
106
107 static int ar71xx_pci_check_error(struct ar71xx_pci_controller *apc, int quiet)
108 {
109 void __iomem *base = apc->cfg_base;
110 u32 pci_err;
111 u32 ahb_err;
112
113 pci_err = __raw_readl(base + AR71XX_PCI_REG_PCI_ERR) & 3;
114 if (pci_err) {
115 if (!quiet) {
116 u32 addr;
117
118 addr = __raw_readl(base + AR71XX_PCI_REG_PCI_ERR_ADDR);
119 pr_crit("ar71xx: %s bus error %d at addr 0x%x\n",
120 "PCI", pci_err, addr);
121 }
122
123 /* clear PCI error status */
124 __raw_writel(pci_err, base + AR71XX_PCI_REG_PCI_ERR);
125 }
126
127 ahb_err = __raw_readl(base + AR71XX_PCI_REG_AHB_ERR) & 1;
128 if (ahb_err) {
129 if (!quiet) {
130 u32 addr;
131
132 addr = __raw_readl(base + AR71XX_PCI_REG_AHB_ERR_ADDR);
133 pr_crit("ar71xx: %s bus error %d at addr 0x%x\n",
134 "AHB", ahb_err, addr);
135 }
136
137 /* clear AHB error status */
138 __raw_writel(ahb_err, base + AR71XX_PCI_REG_AHB_ERR);
139 }
140
141 return !!(ahb_err | pci_err);
142 }
143
144 static inline void ar71xx_pci_local_write(struct ar71xx_pci_controller *apc,
145 int where, int size, u32 value)
146 {
147 void __iomem *base = apc->cfg_base;
148 u32 ad_cbe;
149
150 value = value << (8 * (where & 3));
151
152 ad_cbe = AR71XX_PCI_CRP_CMD_WRITE | (where & ~3);
153 ad_cbe |= ar71xx_pci_get_ble(where, size, 1);
154
155 __raw_writel(ad_cbe, base + AR71XX_PCI_REG_CRP_AD_CBE);
156 __raw_writel(value, base + AR71XX_PCI_REG_CRP_WRDATA);
157 }
158
159 static inline int ar71xx_pci_set_cfgaddr(struct pci_bus *bus,
160 unsigned int devfn,
161 int where, int size, u32 cmd)
162 {
163 struct ar71xx_pci_controller *apc = pci_bus_to_ar71xx_controller(bus);
164 void __iomem *base = apc->cfg_base;
165 u32 addr;
166
167 addr = ar71xx_pci_bus_addr(bus, devfn, where);
168
169 __raw_writel(addr, base + AR71XX_PCI_REG_CFG_AD);
170 __raw_writel(cmd | ar71xx_pci_get_ble(where, size, 0),
171 base + AR71XX_PCI_REG_CFG_CBE);
172
173 return ar71xx_pci_check_error(apc, 1);
174 }
175
176 static int ar71xx_pci_read_config(struct pci_bus *bus, unsigned int devfn,
177 int where, int size, u32 *value)
178 {
179 struct ar71xx_pci_controller *apc = pci_bus_to_ar71xx_controller(bus);
180 void __iomem *base = apc->cfg_base;
181 u32 data;
182 int err;
183 int ret;
184
185 ret = PCIBIOS_SUCCESSFUL;
186 data = ~0;
187
188 err = ar71xx_pci_set_cfgaddr(bus, devfn, where, size,
189 AR71XX_PCI_CFG_CMD_READ);
190 if (err)
191 ret = PCIBIOS_DEVICE_NOT_FOUND;
192 else
193 data = __raw_readl(base + AR71XX_PCI_REG_CFG_RDDATA);
194
195 *value = (data >> (8 * (where & 3))) & ar71xx_pci_read_mask[size & 7];
196
197 return ret;
198 }
199
200 static int ar71xx_pci_write_config(struct pci_bus *bus, unsigned int devfn,
201 int where, int size, u32 value)
202 {
203 struct ar71xx_pci_controller *apc = pci_bus_to_ar71xx_controller(bus);
204 void __iomem *base = apc->cfg_base;
205 int err;
206 int ret;
207
208 value = value << (8 * (where & 3));
209 ret = PCIBIOS_SUCCESSFUL;
210
211 err = ar71xx_pci_set_cfgaddr(bus, devfn, where, size,
212 AR71XX_PCI_CFG_CMD_WRITE);
213 if (err)
214 ret = PCIBIOS_DEVICE_NOT_FOUND;
215 else
216 __raw_writel(value, base + AR71XX_PCI_REG_CFG_WRDATA);
217
218 return ret;
219 }
220
221 static struct pci_ops ar71xx_pci_ops = {
222 .read = ar71xx_pci_read_config,
223 .write = ar71xx_pci_write_config,
224 };
225
226 static void ar71xx_pci_irq_handler(struct irq_desc *desc)
227 {
228 struct ar71xx_pci_controller *apc;
229 void __iomem *base = ath79_reset_base;
230 u32 pending;
231
232 apc = irq_desc_get_handler_data(desc);
233
234 pending = __raw_readl(base + AR71XX_RESET_REG_PCI_INT_STATUS) &
235 __raw_readl(base + AR71XX_RESET_REG_PCI_INT_ENABLE);
236
237 if (pending & AR71XX_PCI_INT_DEV0)
238 generic_handle_irq(apc->irq_base + 0);
239
240 else if (pending & AR71XX_PCI_INT_DEV1)
241 generic_handle_irq(apc->irq_base + 1);
242
243 else if (pending & AR71XX_PCI_INT_DEV2)
244 generic_handle_irq(apc->irq_base + 2);
245
246 else if (pending & AR71XX_PCI_INT_CORE)
247 generic_handle_irq(apc->irq_base + 4);
248
249 else
250 spurious_interrupt();
251 }
252
253 static void ar71xx_pci_irq_unmask(struct irq_data *d)
254 {
255 struct ar71xx_pci_controller *apc;
256 unsigned int irq;
257 void __iomem *base = ath79_reset_base;
258 u32 t;
259
260 apc = irq_data_get_irq_chip_data(d);
261 irq = d->irq - apc->irq_base;
262
263 t = __raw_readl(base + AR71XX_RESET_REG_PCI_INT_ENABLE);
264 __raw_writel(t | (1 << irq), base + AR71XX_RESET_REG_PCI_INT_ENABLE);
265
266 /* flush write */
267 __raw_readl(base + AR71XX_RESET_REG_PCI_INT_ENABLE);
268 }
269
270 static void ar71xx_pci_irq_mask(struct irq_data *d)
271 {
272 struct ar71xx_pci_controller *apc;
273 unsigned int irq;
274 void __iomem *base = ath79_reset_base;
275 u32 t;
276
277 apc = irq_data_get_irq_chip_data(d);
278 irq = d->irq - apc->irq_base;
279
280 t = __raw_readl(base + AR71XX_RESET_REG_PCI_INT_ENABLE);
281 __raw_writel(t & ~(1 << irq), base + AR71XX_RESET_REG_PCI_INT_ENABLE);
282
283 /* flush write */
284 __raw_readl(base + AR71XX_RESET_REG_PCI_INT_ENABLE);
285 }
286
287 static struct irq_chip ar71xx_pci_irq_chip = {
288 .name = "AR71XX PCI",
289 .irq_mask = ar71xx_pci_irq_mask,
290 .irq_unmask = ar71xx_pci_irq_unmask,
291 .irq_mask_ack = ar71xx_pci_irq_mask,
292 };
293
294 static void ar71xx_pci_irq_init(struct ar71xx_pci_controller *apc)
295 {
296 void __iomem *base = ath79_reset_base;
297 int i;
298
299 __raw_writel(0, base + AR71XX_RESET_REG_PCI_INT_ENABLE);
300 __raw_writel(0, base + AR71XX_RESET_REG_PCI_INT_STATUS);
301
302 BUILD_BUG_ON(ATH79_PCI_IRQ_COUNT < AR71XX_PCI_IRQ_COUNT);
303
304 apc->irq_base = ATH79_PCI_IRQ_BASE;
305 for (i = apc->irq_base;
306 i < apc->irq_base + AR71XX_PCI_IRQ_COUNT; i++) {
307 irq_set_chip_and_handler(i, &ar71xx_pci_irq_chip,
308 handle_level_irq);
309 irq_set_chip_data(i, apc);
310 }
311
312 irq_set_chained_handler_and_data(apc->irq, ar71xx_pci_irq_handler,
313 apc);
314 }
315
316 static void ar71xx_pci_reset(void)
317 {
318 ath79_device_reset_set(AR71XX_RESET_PCI_BUS | AR71XX_RESET_PCI_CORE);
319 mdelay(100);
320
321 ath79_device_reset_clear(AR71XX_RESET_PCI_BUS | AR71XX_RESET_PCI_CORE);
322 mdelay(100);
323
324 ath79_ddr_set_pci_windows();
325 mdelay(100);
326 }
327
328 static int ar71xx_pci_probe(struct platform_device *pdev)
329 {
330 struct ar71xx_pci_controller *apc;
331 struct resource *res;
332 u32 t;
333
334 apc = devm_kzalloc(&pdev->dev, sizeof(struct ar71xx_pci_controller),
335 GFP_KERNEL);
336 if (!apc)
337 return -ENOMEM;
338
339 apc->cfg_base = devm_platform_ioremap_resource_byname(pdev,
340 "cfg_base");
341 if (IS_ERR(apc->cfg_base))
342 return PTR_ERR(apc->cfg_base);
343
344 apc->irq = platform_get_irq(pdev, 0);
345 if (apc->irq < 0)
346 return -EINVAL;
347
348 res = platform_get_resource_byname(pdev, IORESOURCE_IO, "io_base");
349 if (!res)
350 return -EINVAL;
351
352 apc->io_res.parent = res;
353 apc->io_res.name = "PCI IO space";
354 apc->io_res.start = res->start;
355 apc->io_res.end = res->end;
356 apc->io_res.flags = IORESOURCE_IO;
357
358 res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mem_base");
359 if (!res)
360 return -EINVAL;
361
362 apc->mem_res.parent = res;
363 apc->mem_res.name = "PCI memory space";
364 apc->mem_res.start = res->start;
365 apc->mem_res.end = res->end;
366 apc->mem_res.flags = IORESOURCE_MEM;
367
368 ar71xx_pci_reset();
369
370 /* setup COMMAND register */
371 t = PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER | PCI_COMMAND_INVALIDATE
372 | PCI_COMMAND_PARITY | PCI_COMMAND_SERR | PCI_COMMAND_FAST_BACK;
373 ar71xx_pci_local_write(apc, PCI_COMMAND, 4, t);
374
375 /* clear bus errors */
376 ar71xx_pci_check_error(apc, 1);
377
378 ar71xx_pci_irq_init(apc);
379
380 apc->pci_ctrl.pci_ops = &ar71xx_pci_ops;
381 apc->pci_ctrl.mem_resource = &apc->mem_res;
382 apc->pci_ctrl.io_resource = &apc->io_res;
383
384 register_pci_controller(&apc->pci_ctrl);
385
386 return 0;
387 }
388
389 static struct platform_driver ar71xx_pci_driver = {
390 .probe = ar71xx_pci_probe,
391 .driver = {
392 .name = "ar71xx-pci",
393 },
394 };
395
396 static int __init ar71xx_pci_init(void)
397 {
398 return platform_driver_register(&ar71xx_pci_driver);
399 }
400
401 postcore_initcall(ar71xx_pci_init);
402
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.