/* SPDX-License-Identifier: GPL-2.0 */
/*
* Apple Peripheral System Controller (PSC)
*
* The PSC is used on the AV Macs to control IO functions not handled
* by the VIAs (Ethernet, DSP, SCC, Sound). This includes nine DMA
* channels.
*
* The first seven DMA channels appear to be "one-shot" and are actually
* sets of two channels; one member is active while the other is being
* configured, and then you flip the active member and start all over again.
* The one-shot channels are grouped together and are:
*
* 1. SCSI
* 2. Ethernet Read
* 3. Ethernet Write
* 4. Floppy Disk Controller
* 5. SCC Channel A Receive
* 6. SCC Channel B Receive
* 7. SCC Channel A Transmit
*
* The remaining two channels are handled somewhat differently. They appear
* to be closely tied and share one set of registers. They also seem to run
* continuously, although how you keep the buffer filled in this scenario is
* not understood as there seems to be only one input and one output buffer
* pointer.
*
* Much of this was extrapolated from what was known about the Ethernet
* registers and subsequently confirmed using MacsBug (ie by pinging the
* machine with easy-to-find patterns and looking for them in the DMA
* buffers, or by sending a file over the serial ports and finding the
* file in the buffers.)
*
* 1999-05-25 (jmt)
*/
#define PSC_BASE (0x50F31000)
/*
* The IER/IFR registers work like the VIA, except that it has 4
* of them each on different interrupt levels, and each register
* set only seems to handle four interrupts instead of seven.
*
* To access a particular set of registers, add 0xn0 to the base
* where n = 3,4,5 or 6.
*/
#define pIFRbase 0x100
#define pIERbase 0x104
/*
* One-shot DMA control registers
*/
#define PSC_MYSTERY 0x804
#define PSC_CTL_BASE 0xC00
#define PSC_SCSI_CTL 0xC00
#define PSC_ENETRD_CTL 0xC10
#define PSC_ENETWR_CTL 0xC20
#define PSC_FDC_CTL 0xC30
#define PSC_SCCA_CTL 0xC40
#define PSC_SCCB_CTL 0xC50
#define PSC_SCCATX_CTL 0xC60
/*
* DMA channels. Add +0x10 for the second channel in the set.
* You're supposed to use one channel while the other runs and
* then flip channels and do the whole thing again.
*/
#define PSC_ADDR_BASE 0x1000
#define PSC_LEN_BASE 0x1004
#define PSC_CMD_BASE 0x1008
#define PSC_SET0 0x00
#define PSC_SET1 0x10
#define PSC_SCSI_ADDR 0x1000 /* confirmed */
#define PSC_SCSI_LEN 0x1004 /* confirmed */
#define PSC_SCSI_CMD 0x1008 /* confirmed */
#define PSC_ENETRD_ADDR 0x1020 /* confirmed */
#define PSC_ENETRD_LEN 0x1024 /* confirmed */
#define PSC_ENETRD_CMD 0x1028 /* confirmed */
#define PSC_ENETWR_ADDR 0x1040 /* confirmed */
#define PSC_ENETWR_LEN 0x1044 /* confirmed */
#define PSC_ENETWR_CMD 0x1048 /* confirmed */
#define PSC_FDC_ADDR 0x1060 /* strongly suspected */
#define PSC_FDC_LEN 0x1064 /* strongly suspected */
#define PSC_FDC_CMD 0x1068 /* strongly suspected */
#define PSC_SCCA_ADDR 0x1080 /* confirmed */
#define PSC_SCCA_LEN 0x1084 /* confirmed */
#define PSC_SCCA_CMD 0x1088 /* confirmed */
#define PSC_SCCB_ADDR 0x10A0 /* confirmed */
#define PSC_SCCB_LEN 0x10A4 /* confirmed */
#define PSC_SCCB_CMD 0x10A8 /* confirmed */
#define PSC_SCCATX_ADDR 0x10C0 /* confirmed */
#define PSC_SCCATX_LEN 0x10C4 /* confirmed */
#define PSC_SCCATX_CMD 0x10C8 /* confirmed */
/*
* Free-running DMA registers. The only part known for sure are the bits in
* the control register, the buffer addresses and the buffer length. Everything
* else is anybody's guess.
*
* These registers seem to be mirrored every thirty-two bytes up until offset
* 0x300. It's safe to assume then that a new set of registers starts there.
*/
#define PSC_SND_CTL 0x200 /*
* [ 16-bit ]
* Sound (Singer?) control register.
*
* bit 0 : ????
* bit 1 : ????
* bit 2 : Set to one to enable sound
* output. Possibly a mute flag.
* bit 3 : ????
* bit 4 : ????
* bit 5 : ????
* bit 6 : Set to one to enable pass-thru
* audio. In this mode the audio data
* seems to appear in both the input
* buffer and the output buffer.
* bit 7 : Set to one to activate the
* sound input DMA or zero to
* disable it.
* bit 8 : Set to one to activate the
* sound output DMA or zero to
* disable it.
* bit 9 : \
* bit 11 : |
* These two bits control the sample
* rate. Usually set to binary 10 and
* MacOS 8.0 says I'm at 48 KHz. Using
* a binary value of 01 makes things
* sound about 1/2 speed (24 KHz?) and
* binary 00 is slower still (22 KHz?)
*
* Setting this to 0x0000 is a good way to
* kill all DMA at boot time so that the
* PSC won't overwrite the kernel image
* with sound data.
*/
/*
* 0x0202 - 0x0203 is unused. Writing there
* seems to clobber the control register.
*/
#define PSC_SND_SOURCE 0x204 /*
* [ 32-bit ]
* Controls input source and volume:
*
* bits 12-15 : input source volume, 0 - F
* bits 16-19 : unknown, always 0x5
* bits 20-23 : input source selection:
* 0x3 = CD Audio
* 0x4 = External Audio
*
* The volume is definitely not the general
* output volume as it doesn't affect the
* alert sound volume.
*/
#define PSC_SND_STATUS1 0x208 /*
* [ 32-bit ]
* Appears to be a read-only status register.
* The usual value is 0x00400002.
*/
#define PSC_SND_HUH3 0x20C /*
* [ 16-bit ]
* Unknown 16-bit value, always 0x0000.
*/
#define PSC_SND_BITS2GO 0x20E /*
* [ 16-bit ]
* Counts down to zero from some constant
* value. The value appears to be the
* number of _bits_ remaining before the
* buffer is full, which would make sense
* since Apple's docs say the sound DMA
* channels are 1 bit wide.
*/
#define PSC_SND_INADDR 0x210 /*
* [ 32-bit ]
* Address of the sound input DMA buffer
*/
#define PSC_SND_OUTADDR 0x214 /*
* [ 32-bit ]
* Address of the sound output DMA buffer
*/
#define PSC_SND_LEN 0x218 /*
* [ 16-bit ]
* Length of both buffers in eight-byte units.
*/
#define PSC_SND_HUH4 0x21A /*
* [ 16-bit ]
* Unknown, always 0x0000.
*/
#define PSC_SND_STATUS2 0x21C /*
* [ 16-bit ]
* Appears to e a read-only status register.
* The usual value is 0x0200.
*/
#define PSC_SND_HUH5 0x21E /*
* [ 16-bit ]
* Unknown, always 0x0000.
*/
#ifndef __ASSEMBLY__
extern volatile __u8 *psc;
extern void psc_register_interrupts(void);
extern void psc_irq_enable(int);
extern void psc_irq_disable(int);
/*
* Access functions
*/
static inline void psc_write_byte(int offset, __u8 data)
{
*((volatile __u8 *)(psc + offset)) = data;
}
static inline void psc_write_word(int offset, __u16 data)
{
*((volatile __u16 *)(psc + offset)) = data;
}
static inline void psc_write_long(int offset, __u32 data)
{
*((volatile __u32 *)(psc + offset)) = data;
}
static inline u8 psc_read_byte(int offset)
{
return *((volatile __u8 *)(psc + offset));
}
static inline u16 psc_read_word(int offset)
{
return *((volatile __u16 *)(psc + offset));
}
static inline u32 psc_read_long(int offset)
{
return *((volatile __u32 *)(psc + offset));
}
#endif /* __ASSEMBLY__ */