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1 /*
2 * init_ohci1394_dma.c - Initializes physical DMA on all OHCI 1394 controllers
3 *
4 * Copyright (C) 2006-2007 Bernhard Kaindl <bk@suse.de>
5 *
6 * Derived from drivers/ieee1394/ohci1394.c and arch/x86/kernel/early-quirks.c
7 * this file has functions to:
8 * - scan the PCI very early on boot for all OHCI 1394-compliant controllers
9 * - reset and initialize them and make them join the IEEE1394 bus and
10 * - enable physical DMA on them to allow remote debugging
11 *
12 * All code and data is marked as __init and __initdata, respective as
13 * during boot, all OHCI1394 controllers may be claimed by the firewire
14 * stack and at this point, this code should not touch them anymore.
15 *
16 * To use physical DMA after the initialization of the firewire stack,
17 * be sure that the stack enables it and (re-)attach after the bus reset
18 * which may be caused by the firewire stack initialization.
19 *
20 * This program is free software; you can redistribute it and/or modify
21 * it under the terms of the GNU General Public License as published by
22 * the Free Software Foundation; either version 2 of the License, or
23 * (at your option) any later version.
24 *
25 * This program is distributed in the hope that it will be useful,
26 * but WITHOUT ANY WARRANTY; without even the implied warranty of
27 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
28 * GNU General Public License for more details.
29 *
30 * You should have received a copy of the GNU General Public License
31 * along with this program; if not, write to the Free Software Foundation,
32 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
33 */
34
35 #include <linux/delay.h>
36 #include <linux/io.h>
37 #include <linux/kernel.h>
38 #include <linux/pci.h> /* for PCI defines */
39 #include <linux/string.h>
40
41 #include <asm/pci-direct.h> /* for direct PCI config space access */
42 #include <asm/fixmap.h>
43
44 #include <linux/init_ohci1394_dma.h>
45 #include "ohci.h"
46
47 int __initdata init_ohci1394_dma_early;
48
49 struct ohci {
50 void __iomem *registers;
51 };
52
53 static inline void reg_write(const struct ohci *ohci, int offset, u32 data)
54 {
55 writel(data, ohci->registers + offset);
56 }
57
58 static inline u32 reg_read(const struct ohci *ohci, int offset)
59 {
60 return readl(ohci->registers + offset);
61 }
62
63 #define OHCI_LOOP_COUNT 100 /* Number of loops for reg read waits */
64
65 /* Reads a PHY register of an OHCI-1394 controller */
66 static inline u8 __init get_phy_reg(struct ohci *ohci, u8 addr)
67 {
68 int i;
69 u32 r;
70
71 reg_write(ohci, OHCI1394_PhyControl, (addr << 8) | 0x00008000);
72
73 for (i = 0; i < OHCI_LOOP_COUNT; i++) {
74 if (reg_read(ohci, OHCI1394_PhyControl) & 0x80000000)
75 break;
76 mdelay(1);
77 }
78 r = reg_read(ohci, OHCI1394_PhyControl);
79
80 return (r & 0x00ff0000) >> 16;
81 }
82
83 /* Writes to a PHY register of an OHCI-1394 controller */
84 static inline void __init set_phy_reg(struct ohci *ohci, u8 addr, u8 data)
85 {
86 int i;
87
88 reg_write(ohci, OHCI1394_PhyControl, (addr << 8) | data | 0x00004000);
89
90 for (i = 0; i < OHCI_LOOP_COUNT; i++) {
91 if (!(reg_read(ohci, OHCI1394_PhyControl) & 0x00004000))
92 break;
93 mdelay(1);
94 }
95 }
96
97 /* Resets an OHCI-1394 controller (for sane state before initialization) */
98 static inline void __init init_ohci1394_soft_reset(struct ohci *ohci)
99 {
100 int i;
101
102 reg_write(ohci, OHCI1394_HCControlSet, OHCI1394_HCControl_softReset);
103
104 for (i = 0; i < OHCI_LOOP_COUNT; i++) {
105 if (!(reg_read(ohci, OHCI1394_HCControlSet)
106 & OHCI1394_HCControl_softReset))
107 break;
108 mdelay(1);
109 }
110 }
111
112 #define OHCI1394_MAX_AT_REQ_RETRIES 0xf
113 #define OHCI1394_MAX_AT_RESP_RETRIES 0x2
114 #define OHCI1394_MAX_PHYS_RESP_RETRIES 0x8
115
116 /* Basic OHCI-1394 register and port inititalization */
117 static inline void __init init_ohci1394_initialize(struct ohci *ohci)
118 {
119 u32 bus_options;
120 int num_ports, i;
121
122 /* Put some defaults to these undefined bus options */
123 bus_options = reg_read(ohci, OHCI1394_BusOptions);
124 bus_options |= 0x60000000; /* Enable CMC and ISC */
125 bus_options &= ~0x00ff0000; /* XXX: Set cyc_clk_acc to zero for now */
126 bus_options &= ~0x18000000; /* Disable PMC and BMC */
127 reg_write(ohci, OHCI1394_BusOptions, bus_options);
128
129 /* Set the bus number */
130 reg_write(ohci, OHCI1394_NodeID, 0x0000ffc0);
131
132 /* Enable posted writes */
133 reg_write(ohci, OHCI1394_HCControlSet,
134 OHCI1394_HCControl_postedWriteEnable);
135
136 /* Clear link control register */
137 reg_write(ohci, OHCI1394_LinkControlClear, 0xffffffff);
138
139 /* enable phys */
140 reg_write(ohci, OHCI1394_LinkControlSet,
141 OHCI1394_LinkControl_rcvPhyPkt);
142
143 /* Don't accept phy packets into AR request context */
144 reg_write(ohci, OHCI1394_LinkControlClear, 0x00000400);
145
146 /* Clear the Isochonouys interrupt masks */
147 reg_write(ohci, OHCI1394_IsoRecvIntMaskClear, 0xffffffff);
148 reg_write(ohci, OHCI1394_IsoRecvIntEventClear, 0xffffffff);
149 reg_write(ohci, OHCI1394_IsoXmitIntMaskClear, 0xffffffff);
150 reg_write(ohci, OHCI1394_IsoXmitIntEventClear, 0xffffffff);
151
152 /* Accept asynchronous transfer requests from all nodes for now */
153 reg_write(ohci, OHCI1394_AsReqFilterHiSet, 0x80000000);
154
155 /* Specify asynchronous transfer retries */
156 reg_write(ohci, OHCI1394_ATRetries,
157 OHCI1394_MAX_AT_REQ_RETRIES |
158 (OHCI1394_MAX_AT_RESP_RETRIES<<4) |
159 (OHCI1394_MAX_PHYS_RESP_RETRIES<<8));
160
161 /* We don't want hardware swapping */
162 reg_write(ohci, OHCI1394_HCControlClear,
163 OHCI1394_HCControl_noByteSwapData);
164
165 /* Enable link */
166 reg_write(ohci, OHCI1394_HCControlSet, OHCI1394_HCControl_linkEnable);
167
168 /* If anything is connected to a port, make sure it is enabled */
169 num_ports = get_phy_reg(ohci, 2) & 0xf;
170 for (i = 0; i < num_ports; i++) {
171 unsigned int status;
172
173 set_phy_reg(ohci, 7, i);
174 status = get_phy_reg(ohci, 8);
175
176 if (status & 0x20)
177 set_phy_reg(ohci, 8, status & ~1);
178 }
179 }
180
181 /**
182 * init_ohci1394_wait_for_busresets - wait until bus resets are completed
183 *
184 * OHCI1394 initialization itself and any device going on- or offline
185 * and any cable issue cause a IEEE1394 bus reset. The OHCI1394 spec
186 * specifies that physical DMA is disabled on each bus reset and it
187 * has to be enabled after each bus reset when needed. We resort
188 * to polling here because on early boot, we have no interrupts.
189 */
190 static inline void __init init_ohci1394_wait_for_busresets(struct ohci *ohci)
191 {
192 int i, events;
193
194 for (i = 0; i < 9; i++) {
195 mdelay(200);
196 events = reg_read(ohci, OHCI1394_IntEventSet);
197 if (events & OHCI1394_busReset)
198 reg_write(ohci, OHCI1394_IntEventClear,
199 OHCI1394_busReset);
200 }
201 }
202
203 /**
204 * init_ohci1394_enable_physical_dma - Enable physical DMA for remote debugging
205 * This enables remote DMA access over IEEE1394 from every host for the low
206 * 4GB of address space. DMA accesses above 4GB are not available currently.
207 */
208 static inline void __init init_ohci1394_enable_physical_dma(struct ohci *ohci)
209 {
210 reg_write(ohci, OHCI1394_PhyReqFilterHiSet, 0xffffffff);
211 reg_write(ohci, OHCI1394_PhyReqFilterLoSet, 0xffffffff);
212 reg_write(ohci, OHCI1394_PhyUpperBound, 0xffff0000);
213 }
214
215 /**
216 * init_ohci1394_reset_and_init_dma - init controller and enable DMA
217 * This initializes the given controller and enables physical DMA engine in it.
218 */
219 static inline void __init init_ohci1394_reset_and_init_dma(struct ohci *ohci)
220 {
221 /* Start off with a soft reset, clears everything to a sane state. */
222 init_ohci1394_soft_reset(ohci);
223
224 /* Accessing some registers without LPS enabled may cause lock up */
225 reg_write(ohci, OHCI1394_HCControlSet, OHCI1394_HCControl_LPS);
226
227 /* Disable and clear interrupts */
228 reg_write(ohci, OHCI1394_IntEventClear, 0xffffffff);
229 reg_write(ohci, OHCI1394_IntMaskClear, 0xffffffff);
230
231 mdelay(50); /* Wait 50msec to make sure we have full link enabled */
232
233 init_ohci1394_initialize(ohci);
234 /*
235 * The initialization causes at least one IEEE1394 bus reset. Enabling
236 * physical DMA only works *after* *all* bus resets have calmed down:
237 */
238 init_ohci1394_wait_for_busresets(ohci);
239
240 /* We had to wait and do this now if we want to debug early problems */
241 init_ohci1394_enable_physical_dma(ohci);
242 }
243
244 /**
245 * init_ohci1394_controller - Map the registers of the controller and init DMA
246 * This maps the registers of the specified controller and initializes it
247 */
248 static inline void __init init_ohci1394_controller(int num, int slot, int func)
249 {
250 unsigned long ohci_base;
251 struct ohci ohci;
252
253 printk(KERN_INFO "init_ohci1394_dma: initializing OHCI-1394"
254 " at %02x:%02x.%x\n", num, slot, func);
255
256 ohci_base = read_pci_config(num, slot, func, PCI_BASE_ADDRESS_0+(0<<2))
257 & PCI_BASE_ADDRESS_MEM_MASK;
258
259 set_fixmap_nocache(FIX_OHCI1394_BASE, ohci_base);
260
261 ohci.registers = (void __iomem *)fix_to_virt(FIX_OHCI1394_BASE);
262
263 init_ohci1394_reset_and_init_dma(&ohci);
264 }
265
266 /**
267 * debug_init_ohci1394_dma - scan for OHCI1394 controllers and init DMA on them
268 * Scans the whole PCI space for OHCI1394 controllers and inits DMA on them
269 */
270 void __init init_ohci1394_dma_on_all_controllers(void)
271 {
272 int num, slot, func;
273 u32 class;
274
275 if (!early_pci_allowed())
276 return;
277
278 /* Poor man's PCI discovery, the only thing we can do at early boot */
279 for (num = 0; num < 32; num++) {
280 for (slot = 0; slot < 32; slot++) {
281 for (func = 0; func < 8; func++) {
282 class = read_pci_config(num, slot, func,
283 PCI_CLASS_REVISION);
284 if (class == 0xffffffff)
285 continue; /* No device at this func */
286
287 if (class>>8 != PCI_CLASS_SERIAL_FIREWIRE_OHCI)
288 continue; /* Not an OHCI-1394 device */
289
290 init_ohci1394_controller(num, slot, func);
291 break; /* Assume one controller per device */
292 }
293 }
294 }
295 printk(KERN_INFO "init_ohci1394_dma: finished initializing OHCI DMA\n");
296 }
297
298 /**
299 * setup_init_ohci1394_early - enables early OHCI1394 DMA initialization
300 */
301 static int __init setup_ohci1394_dma(char *opt)
302 {
303 if (!strcmp(opt, "early"))
304 init_ohci1394_dma_early = 1;
305 return 0;
306 }
307
308 /* passing ohci1394_dma=early on boot causes early OHCI1394 DMA initialization */
309 early_param("ohci1394_dma", setup_ohci1394_dma);