1 /*
2 * Apple Peripheral System Controller (PSC)
3 *
4 * The PSC is used on the AV Macs to control IO functions not handled
5 * by the VIAs (Ethernet, DSP, SCC, Sound). This includes nine DMA
6 * channels.
7 *
8 * The first seven DMA channels appear to be "one-shot" and are actually
9 * sets of two channels; one member is active while the other is being
10 * configured, and then you flip the active member and start all over again.
11 * The one-shot channels are grouped together and are:
12 *
13 * 1. SCSI
14 * 2. Ethernet Read
15 * 3. Ethernet Write
16 * 4. Floppy Disk Controller
17 * 5. SCC Channel A Receive
18 * 6. SCC Channel B Receive
19 * 7. SCC Channel A Transmit
20 *
21 * The remaining two channels are handled somewhat differently. They appear
22 * to be closely tied and share one set of registers. They also seem to run
23 * continuously, although how you keep the buffer filled in this scenario is
24 * not understood as there seems to be only one input and one output buffer
25 * pointer.
26 *
27 * Much of this was extrapolated from what was known about the Ethernet
28 * registers and subsequently confirmed using MacsBug (ie by pinging the
29 * machine with easy-to-find patterns and looking for them in the DMA
30 * buffers, or by sending a file over the serial ports and finding the
31 * file in the buffers.)
32 *
33 * 1999-05-25 (jmt)
34 */
35
36 #define PSC_BASE (0x50F31000)
37
38 /*
39 * The IER/IFR registers work like the VIA, except that it has 4
40 * of them each on different interrupt levels, and each register
41 * set only seems to handle four interrupts instead of seven.
42 *
43 * To access a particular set of registers, add 0xn0 to the base
44 * where n = 3,4,5 or 6.
45 */
46
47 #define pIFRbase 0x100
48 #define pIERbase 0x104
49
50 /*
51 * One-shot DMA control registers
52 */
53
54 #define PSC_MYSTERY 0x804
55
56 #define PSC_CTL_BASE 0xC00
57
58 #define PSC_SCSI_CTL 0xC00
59 #define PSC_ENETRD_CTL 0xC10
60 #define PSC_ENETWR_CTL 0xC20
61 #define PSC_FDC_CTL 0xC30
62 #define PSC_SCCA_CTL 0xC40
63 #define PSC_SCCB_CTL 0xC50
64 #define PSC_SCCATX_CTL 0xC60
65
66 /*
67 * DMA channels. Add +0x10 for the second channel in the set.
68 * You're supposed to use one channel while the other runs and
69 * then flip channels and do the whole thing again.
70 */
71
72 #define PSC_ADDR_BASE 0x1000
73 #define PSC_LEN_BASE 0x1004
74 #define PSC_CMD_BASE 0x1008
75
76 #define PSC_SET0 0x00
77 #define PSC_SET1 0x10
78
79 #define PSC_SCSI_ADDR 0x1000 /* confirmed */
80 #define PSC_SCSI_LEN 0x1004 /* confirmed */
81 #define PSC_SCSI_CMD 0x1008 /* confirmed */
82 #define PSC_ENETRD_ADDR 0x1020 /* confirmed */
83 #define PSC_ENETRD_LEN 0x1024 /* confirmed */
84 #define PSC_ENETRD_CMD 0x1028 /* confirmed */
85 #define PSC_ENETWR_ADDR 0x1040 /* confirmed */
86 #define PSC_ENETWR_LEN 0x1044 /* confirmed */
87 #define PSC_ENETWR_CMD 0x1048 /* confirmed */
88 #define PSC_FDC_ADDR 0x1060 /* strongly suspected */
89 #define PSC_FDC_LEN 0x1064 /* strongly suspected */
90 #define PSC_FDC_CMD 0x1068 /* strongly suspected */
91 #define PSC_SCCA_ADDR 0x1080 /* confirmed */
92 #define PSC_SCCA_LEN 0x1084 /* confirmed */
93 #define PSC_SCCA_CMD 0x1088 /* confirmed */
94 #define PSC_SCCB_ADDR 0x10A0 /* confirmed */
95 #define PSC_SCCB_LEN 0x10A4 /* confirmed */
96 #define PSC_SCCB_CMD 0x10A8 /* confirmed */
97 #define PSC_SCCATX_ADDR 0x10C0 /* confirmed */
98 #define PSC_SCCATX_LEN 0x10C4 /* confirmed */
99 #define PSC_SCCATX_CMD 0x10C8 /* confirmed */
100
101 /*
102 * Free-running DMA registers. The only part known for sure are the bits in
103 * the control register, the buffer addresses and the buffer length. Everything
104 * else is anybody's guess.
105 *
106 * These registers seem to be mirrored every thirty-two bytes up until offset
107 * 0x300. It's safe to assume then that a new set of registers starts there.
108 */
109
110 #define PSC_SND_CTL 0x200 /*
111 * [ 16-bit ]
112 * Sound (Singer?) control register.
113 *
114 * bit 0 : ????
115 * bit 1 : ????
116 * bit 2 : Set to one to enable sound
117 * output. Possibly a mute flag.
118 * bit 3 : ????
119 * bit 4 : ????
120 * bit 5 : ????
121 * bit 6 : Set to one to enable pass-thru
122 * audio. In this mode the audio data
123 * seems to appear in both the input
124 * buffer and the output buffer.
125 * bit 7 : Set to one to activate the
126 * sound input DMA or zero to
127 * disable it.
128 * bit 8 : Set to one to activate the
129 * sound output DMA or zero to
130 * disable it.
131 * bit 9 : \
132 * bit 11 : |
133 * These two bits control the sample
134 * rate. Usually set to binary 10 and
135 * MacOS 8.0 says I'm at 48 KHz. Using
136 * a binary value of 01 makes things
137 * sound about 1/2 speed (24 KHz?) and
138 * binary 00 is slower still (22 KHz?)
139 *
140 * Setting this to 0x0000 is a good way to
141 * kill all DMA at boot time so that the
142 * PSC won't overwrite the kernel image
143 * with sound data.
144 */
145
146 /*
147 * 0x0202 - 0x0203 is unused. Writing there
148 * seems to clobber the control register.
149 */
150
151 #define PSC_SND_SOURCE 0x204 /*
152 * [ 32-bit ]
153 * Controls input source and volume:
154 *
155 * bits 12-15 : input source volume, 0 - F
156 * bits 16-19 : unknown, always 0x5
157 * bits 20-23 : input source selection:
158 * 0x3 = CD Audio
159 * 0x4 = External Audio
160 *
161 * The volume is definitely not the general
162 * output volume as it doesn't affect the
163 * alert sound volume.
164 */
165 #define PSC_SND_STATUS1 0x208 /*
166 * [ 32-bit ]
167 * Appears to be a read-only status register.
168 * The usual value is 0x00400002.
169 */
170 #define PSC_SND_HUH3 0x20C /*
171 * [ 16-bit ]
172 * Unknown 16-bit value, always 0x0000.
173 */
174 #define PSC_SND_BITS2GO 0x20E /*
175 * [ 16-bit ]
176 * Counts down to zero from some constant
177 * value. The value appears to be the
178 * number of _bits_ remaining before the
179 * buffer is full, which would make sense
180 * since Apple's docs say the sound DMA
181 * channels are 1 bit wide.
182 */
183 #define PSC_SND_INADDR 0x210 /*
184 * [ 32-bit ]
185 * Address of the sound input DMA buffer
186 */
187 #define PSC_SND_OUTADDR 0x214 /*
188 * [ 32-bit ]
189 * Address of the sound output DMA buffer
190 */
191 #define PSC_SND_LEN 0x218 /*
192 * [ 16-bit ]
193 * Length of both buffers in eight-byte units.
194 */
195 #define PSC_SND_HUH4 0x21A /*
196 * [ 16-bit ]
197 * Unknown, always 0x0000.
198 */
199 #define PSC_SND_STATUS2 0x21C /*
200 * [ 16-bit ]
201 * Appears to e a read-only status register.
202 * The usual value is 0x0200.
203 */
204 #define PSC_SND_HUH5 0x21E /*
205 * [ 16-bit ]
206 * Unknown, always 0x0000.
207 */
208
209 #ifndef __ASSEMBLY__
210
211 extern volatile __u8 *psc;
212 extern int psc_present;
213
214 /*
215 * Access functions
216 */
217
psc_write_byte(int offset,__u8 data)218 static inline void psc_write_byte(int offset, __u8 data)
219 {
220 *((volatile __u8 *)(psc + offset)) = data;
221 }
222
psc_write_word(int offset,__u16 data)223 static inline void psc_write_word(int offset, __u16 data)
224 {
225 *((volatile __u16 *)(psc + offset)) = data;
226 }
227
psc_write_long(int offset,__u32 data)228 static inline void psc_write_long(int offset, __u32 data)
229 {
230 *((volatile __u32 *)(psc + offset)) = data;
231 }
232
psc_read_byte(int offset)233 static inline u8 psc_read_byte(int offset)
234 {
235 return *((volatile __u8 *)(psc + offset));
236 }
237
psc_read_word(int offset)238 static inline u16 psc_read_word(int offset)
239 {
240 return *((volatile __u16 *)(psc + offset));
241 }
242
psc_read_long(int offset)243 static inline u32 psc_read_long(int offset)
244 {
245 return *((volatile __u32 *)(psc + offset));
246 }
247
248 #endif /* __ASSEMBLY__ */
249