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 */ 217 218 static inline void psc_write_byte(int offset, __u8 data) 219 { 220 *((volatile __u8 *)(psc + offset)) = data; 221 } 222 223 static inline void psc_write_word(int offset, __u16 data) 224 { 225 *((volatile __u16 *)(psc + offset)) = data; 226 } 227 228 static inline void psc_write_long(int offset, __u32 data) 229 { 230 *((volatile __u32 *)(psc + offset)) = data; 231 } 232 233 static inline u8 psc_read_byte(int offset) 234 { 235 return *((volatile __u8 *)(psc + offset)); 236 } 237 238 static inline u16 psc_read_word(int offset) 239 { 240 return *((volatile __u16 *)(psc + offset)); 241 } 242 243 static inline u32 psc_read_long(int offset) 244 { 245 return *((volatile __u32 *)(psc + offset)); 246 } 247 248 #endif /* __ASSEMBLY__ */ 249