1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Apple Peripheral System Controller (PSC) 4 * 5 * The PSC is used on the AV Macs to control IO functions not handled 6 * by the VIAs (Ethernet, DSP, SCC, Sound). This includes nine DMA 7 * channels. 8 * 9 * The first seven DMA channels appear to be "one-shot" and are actually 10 * sets of two channels; one member is active while the other is being 11 * configured, and then you flip the active member and start all over again. 12 * The one-shot channels are grouped together and are: 13 * 14 * 1. SCSI 15 * 2. Ethernet Read 16 * 3. Ethernet Write 17 * 4. Floppy Disk Controller 18 * 5. SCC Channel A Receive 19 * 6. SCC Channel B Receive 20 * 7. SCC Channel A Transmit 21 * 22 * The remaining two channels are handled somewhat differently. They appear 23 * to be closely tied and share one set of registers. They also seem to run 24 * continuously, although how you keep the buffer filled in this scenario is 25 * not understood as there seems to be only one input and one output buffer 26 * pointer. 27 * 28 * Much of this was extrapolated from what was known about the Ethernet 29 * registers and subsequently confirmed using MacsBug (ie by pinging the 30 * machine with easy-to-find patterns and looking for them in the DMA 31 * buffers, or by sending a file over the serial ports and finding the 32 * file in the buffers.) 33 * 34 * 1999-05-25 (jmt) 35 */ 36 37 #define PSC_BASE (0x50F31000) 38 39 /* 40 * The IER/IFR registers work like the VIA, except that it has 4 41 * of them each on different interrupt levels, and each register 42 * set only seems to handle four interrupts instead of seven. 43 * 44 * To access a particular set of registers, add 0xn0 to the base 45 * where n = 3,4,5 or 6. 46 */ 47 48 #define pIFRbase 0x100 49 #define pIERbase 0x104 50 51 /* 52 * One-shot DMA control registers 53 */ 54 55 #define PSC_MYSTERY 0x804 56 57 #define PSC_CTL_BASE 0xC00 58 59 #define PSC_SCSI_CTL 0xC00 60 #define PSC_ENETRD_CTL 0xC10 61 #define PSC_ENETWR_CTL 0xC20 62 #define PSC_FDC_CTL 0xC30 63 #define PSC_SCCA_CTL 0xC40 64 #define PSC_SCCB_CTL 0xC50 65 #define PSC_SCCATX_CTL 0xC60 66 67 /* 68 * DMA channels. Add +0x10 for the second channel in the set. 69 * You're supposed to use one channel while the other runs and 70 * then flip channels and do the whole thing again. 71 */ 72 73 #define PSC_ADDR_BASE 0x1000 74 #define PSC_LEN_BASE 0x1004 75 #define PSC_CMD_BASE 0x1008 76 77 #define PSC_SET0 0x00 78 #define PSC_SET1 0x10 79 80 #define PSC_SCSI_ADDR 0x1000 /* confirmed */ 81 #define PSC_SCSI_LEN 0x1004 /* confirmed */ 82 #define PSC_SCSI_CMD 0x1008 /* confirmed */ 83 #define PSC_ENETRD_ADDR 0x1020 /* confirmed */ 84 #define PSC_ENETRD_LEN 0x1024 /* confirmed */ 85 #define PSC_ENETRD_CMD 0x1028 /* confirmed */ 86 #define PSC_ENETWR_ADDR 0x1040 /* confirmed */ 87 #define PSC_ENETWR_LEN 0x1044 /* confirmed */ 88 #define PSC_ENETWR_CMD 0x1048 /* confirmed */ 89 #define PSC_FDC_ADDR 0x1060 /* strongly suspected */ 90 #define PSC_FDC_LEN 0x1064 /* strongly suspected */ 91 #define PSC_FDC_CMD 0x1068 /* strongly suspected */ 92 #define PSC_SCCA_ADDR 0x1080 /* confirmed */ 93 #define PSC_SCCA_LEN 0x1084 /* confirmed */ 94 #define PSC_SCCA_CMD 0x1088 /* confirmed */ 95 #define PSC_SCCB_ADDR 0x10A0 /* confirmed */ 96 #define PSC_SCCB_LEN 0x10A4 /* confirmed */ 97 #define PSC_SCCB_CMD 0x10A8 /* confirmed */ 98 #define PSC_SCCATX_ADDR 0x10C0 /* confirmed */ 99 #define PSC_SCCATX_LEN 0x10C4 /* confirmed */ 100 #define PSC_SCCATX_CMD 0x10C8 /* confirmed */ 101 102 /* 103 * Free-running DMA registers. The only part known for sure are the bits in 104 * the control register, the buffer addresses and the buffer length. Everything 105 * else is anybody's guess. 106 * 107 * These registers seem to be mirrored every thirty-two bytes up until offset 108 * 0x300. It's safe to assume then that a new set of registers starts there. 109 */ 110 111 #define PSC_SND_CTL 0x200 /* 112 * [ 16-bit ] 113 * Sound (Singer?) control register. 114 * 115 * bit 0 : ???? 116 * bit 1 : ???? 117 * bit 2 : Set to one to enable sound 118 * output. Possibly a mute flag. 119 * bit 3 : ???? 120 * bit 4 : ???? 121 * bit 5 : ???? 122 * bit 6 : Set to one to enable pass-thru 123 * audio. In this mode the audio data 124 * seems to appear in both the input 125 * buffer and the output buffer. 126 * bit 7 : Set to one to activate the 127 * sound input DMA or zero to 128 * disable it. 129 * bit 8 : Set to one to activate the 130 * sound output DMA or zero to 131 * disable it. 132 * bit 9 : \ 133 * bit 11 : | 134 * These two bits control the sample 135 * rate. Usually set to binary 10 and 136 * MacOS 8.0 says I'm at 48 KHz. Using 137 * a binary value of 01 makes things 138 * sound about 1/2 speed (24 KHz?) and 139 * binary 00 is slower still (22 KHz?) 140 * 141 * Setting this to 0x0000 is a good way to 142 * kill all DMA at boot time so that the 143 * PSC won't overwrite the kernel image 144 * with sound data. 145 */ 146 147 /* 148 * 0x0202 - 0x0203 is unused. Writing there 149 * seems to clobber the control register. 150 */ 151 152 #define PSC_SND_SOURCE 0x204 /* 153 * [ 32-bit ] 154 * Controls input source and volume: 155 * 156 * bits 12-15 : input source volume, 0 - F 157 * bits 16-19 : unknown, always 0x5 158 * bits 20-23 : input source selection: 159 * 0x3 = CD Audio 160 * 0x4 = External Audio 161 * 162 * The volume is definitely not the general 163 * output volume as it doesn't affect the 164 * alert sound volume. 165 */ 166 #define PSC_SND_STATUS1 0x208 /* 167 * [ 32-bit ] 168 * Appears to be a read-only status register. 169 * The usual value is 0x00400002. 170 */ 171 #define PSC_SND_HUH3 0x20C /* 172 * [ 16-bit ] 173 * Unknown 16-bit value, always 0x0000. 174 */ 175 #define PSC_SND_BITS2GO 0x20E /* 176 * [ 16-bit ] 177 * Counts down to zero from some constant 178 * value. The value appears to be the 179 * number of _bits_ remaining before the 180 * buffer is full, which would make sense 181 * since Apple's docs say the sound DMA 182 * channels are 1 bit wide. 183 */ 184 #define PSC_SND_INADDR 0x210 /* 185 * [ 32-bit ] 186 * Address of the sound input DMA buffer 187 */ 188 #define PSC_SND_OUTADDR 0x214 /* 189 * [ 32-bit ] 190 * Address of the sound output DMA buffer 191 */ 192 #define PSC_SND_LEN 0x218 /* 193 * [ 16-bit ] 194 * Length of both buffers in eight-byte units. 195 */ 196 #define PSC_SND_HUH4 0x21A /* 197 * [ 16-bit ] 198 * Unknown, always 0x0000. 199 */ 200 #define PSC_SND_STATUS2 0x21C /* 201 * [ 16-bit ] 202 * Appears to e a read-only status register. 203 * The usual value is 0x0200. 204 */ 205 #define PSC_SND_HUH5 0x21E /* 206 * [ 16-bit ] 207 * Unknown, always 0x0000. 208 */ 209 210 #ifndef __ASSEMBLY__ 211 212 extern volatile __u8 *psc; 213 214 extern void psc_register_interrupts(void); 215 extern void psc_irq_enable(int); 216 extern void psc_irq_disable(int); 217 218 /* 219 * Access functions 220 */ 221 222 static inline void psc_write_byte(int offset, __u8 data) 223 { 224 *((volatile __u8 *)(psc + offset)) = data; 225 } 226 227 static inline void psc_write_word(int offset, __u16 data) 228 { 229 *((volatile __u16 *)(psc + offset)) = data; 230 } 231 232 static inline void psc_write_long(int offset, __u32 data) 233 { 234 *((volatile __u32 *)(psc + offset)) = data; 235 } 236 237 static inline u8 psc_read_byte(int offset) 238 { 239 return *((volatile __u8 *)(psc + offset)); 240 } 241 242 static inline u16 psc_read_word(int offset) 243 { 244 return *((volatile __u16 *)(psc + offset)); 245 } 246 247 static inline u32 psc_read_long(int offset) 248 { 249 return *((volatile __u32 *)(psc + offset)); 250 } 251 252 #endif /* __ASSEMBLY__ */ 253