diff options
Diffstat (limited to 'arch/m68k/mac/psc.c')
| -rw-r--r-- | arch/m68k/mac/psc.c | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/arch/m68k/mac/psc.c b/arch/m68k/mac/psc.c new file mode 100644 index 0000000000..0d0965b19c --- /dev/null +++ b/arch/m68k/mac/psc.c @@ -0,0 +1,166 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * 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). + * + * TO DO: + * + * Try to figure out what's going on in pIFR5 and pIFR6. There seem to be + * persisant interrupt conditions in those registers and I have no idea what + * they are. Granted it doesn't affect since we're not enabling any interrupts + * on those levels at the moment, but it would be nice to know. I have a feeling + * they aren't actually interrupt lines but data lines (to the DSP?) + */ + +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/delay.h> +#include <linux/init.h> +#include <linux/irq.h> + +#include <asm/traps.h> +#include <asm/macintosh.h> +#include <asm/macints.h> +#include <asm/mac_psc.h> + +#define DEBUG_PSC + +volatile __u8 *psc; +EXPORT_SYMBOL_GPL(psc); + +/* + * Debugging dump, used in various places to see what's going on. + */ + +static void psc_debug_dump(void) +{ + int i; + + if (!psc) + return; + + for (i = 0x30 ; i < 0x70 ; i += 0x10) { + printk(KERN_DEBUG "PSC #%d: IFR = 0x%02X IER = 0x%02X\n", + i >> 4, + (int) psc_read_byte(pIFRbase + i), + (int) psc_read_byte(pIERbase + i)); + } +} + +/* + * Try to kill all DMA channels on the PSC. Not sure how this his + * supposed to work; this is code lifted from macmace.c and then + * expanded to cover what I think are the other 7 channels. + */ + +static __init void psc_dma_die_die_die(void) +{ + int i; + + for (i = 0 ; i < 9 ; i++) { + psc_write_word(PSC_CTL_BASE + (i << 4), 0x8800); + psc_write_word(PSC_CTL_BASE + (i << 4), 0x1000); + psc_write_word(PSC_CMD_BASE + (i << 5), 0x1100); + psc_write_word(PSC_CMD_BASE + (i << 5) + 0x10, 0x1100); + } +} + +/* + * Initialize the PSC. For now this just involves shutting down all + * interrupt sources using the IERs. + */ + +void __init psc_init(void) +{ + int i; + + if (macintosh_config->ident != MAC_MODEL_C660 + && macintosh_config->ident != MAC_MODEL_Q840) + { + psc = NULL; + return; + } + + /* + * The PSC is always at the same spot, but using psc + * keeps things consistent with the psc_xxxx functions. + */ + + psc = (void *) PSC_BASE; + + pr_debug("PSC detected at %p\n", psc); + + psc_dma_die_die_die(); + +#ifdef DEBUG_PSC + psc_debug_dump(); +#endif + /* + * Mask and clear all possible interrupts + */ + + for (i = 0x30 ; i < 0x70 ; i += 0x10) { + psc_write_byte(pIERbase + i, 0x0F); + psc_write_byte(pIFRbase + i, 0x0F); + } +} + +/* + * PSC interrupt handler. It's a lot like the VIA interrupt handler. + */ + +static void psc_irq(struct irq_desc *desc) +{ + unsigned int offset = (unsigned int)irq_desc_get_handler_data(desc); + unsigned int irq = irq_desc_get_irq(desc); + int pIFR = pIFRbase + offset; + int pIER = pIERbase + offset; + int irq_num; + unsigned char irq_bit, events; + + events = psc_read_byte(pIFR) & psc_read_byte(pIER) & 0xF; + if (!events) + return; + + irq_num = irq << 3; + irq_bit = 1; + do { + if (events & irq_bit) { + psc_write_byte(pIFR, irq_bit); + generic_handle_irq(irq_num); + } + irq_num++; + irq_bit <<= 1; + } while (events >= irq_bit); +} + +/* + * Register the PSC interrupt dispatchers for autovector interrupts 3-6. + */ + +void __init psc_register_interrupts(void) +{ + irq_set_chained_handler_and_data(IRQ_AUTO_3, psc_irq, (void *)0x30); + irq_set_chained_handler_and_data(IRQ_AUTO_4, psc_irq, (void *)0x40); + irq_set_chained_handler_and_data(IRQ_AUTO_5, psc_irq, (void *)0x50); + irq_set_chained_handler_and_data(IRQ_AUTO_6, psc_irq, (void *)0x60); +} + +void psc_irq_enable(int irq) { + int irq_src = IRQ_SRC(irq); + int irq_idx = IRQ_IDX(irq); + int pIER = pIERbase + (irq_src << 4); + + psc_write_byte(pIER, (1 << irq_idx) | 0x80); +} + +void psc_irq_disable(int irq) { + int irq_src = IRQ_SRC(irq); + int irq_idx = IRQ_IDX(irq); + int pIER = pIERbase + (irq_src << 4); + + psc_write_byte(pIER, 1 << irq_idx); +} |