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). 6 * 7 * TO DO: 8 * 9 * Try to figure out what's going on in pIFR5 and pIFR6. There seem to be 10 * persisant interrupt conditions in those registers and I have no idea what 11 * they are. Granted it doesn't affect since we're not enabling any interrupts 12 * on those levels at the moment, but it would be nice to know. I have a feeling 13 * they aren't actually interrupt lines but data lines (to the DSP?) 14 */ 15 16 #include <linux/types.h> 17 #include <linux/kernel.h> 18 #include <linux/mm.h> 19 #include <linux/delay.h> 20 #include <linux/init.h> 21 #include <linux/irq.h> 22 23 #include <asm/traps.h> 24 #include <asm/macintosh.h> 25 #include <asm/macints.h> 26 #include <asm/mac_psc.h> 27 28 #define DEBUG_PSC 29 30 int psc_present; 31 volatile __u8 *psc; 32 33 /* 34 * Debugging dump, used in various places to see what's going on. 35 */ 36 37 static void psc_debug_dump(void) 38 { 39 int i; 40 41 if (!psc_present) return; 42 for (i = 0x30 ; i < 0x70 ; i += 0x10) { 43 printk("PSC #%d: IFR = 0x%02X IER = 0x%02X\n", 44 i >> 4, 45 (int) psc_read_byte(pIFRbase + i), 46 (int) psc_read_byte(pIERbase + i)); 47 } 48 } 49 50 /* 51 * Try to kill all DMA channels on the PSC. Not sure how this his 52 * supposed to work; this is code lifted from macmace.c and then 53 * expanded to cover what I think are the other 7 channels. 54 */ 55 56 static __init void psc_dma_die_die_die(void) 57 { 58 int i; 59 60 printk("Killing all PSC DMA channels..."); 61 for (i = 0 ; i < 9 ; i++) { 62 psc_write_word(PSC_CTL_BASE + (i << 4), 0x8800); 63 psc_write_word(PSC_CTL_BASE + (i << 4), 0x1000); 64 psc_write_word(PSC_CMD_BASE + (i << 5), 0x1100); 65 psc_write_word(PSC_CMD_BASE + (i << 5) + 0x10, 0x1100); 66 } 67 printk("done!\n"); 68 } 69 70 /* 71 * Initialize the PSC. For now this just involves shutting down all 72 * interrupt sources using the IERs. 73 */ 74 75 void __init psc_init(void) 76 { 77 int i; 78 79 if (macintosh_config->ident != MAC_MODEL_C660 80 && macintosh_config->ident != MAC_MODEL_Q840) 81 { 82 psc = NULL; 83 psc_present = 0; 84 return; 85 } 86 87 /* 88 * The PSC is always at the same spot, but using psc 89 * keeps things consistent with the psc_xxxx functions. 90 */ 91 92 psc = (void *) PSC_BASE; 93 psc_present = 1; 94 95 printk("PSC detected at %p\n", psc); 96 97 psc_dma_die_die_die(); 98 99 #ifdef DEBUG_PSC 100 psc_debug_dump(); 101 #endif 102 /* 103 * Mask and clear all possible interrupts 104 */ 105 106 for (i = 0x30 ; i < 0x70 ; i += 0x10) { 107 psc_write_byte(pIERbase + i, 0x0F); 108 psc_write_byte(pIFRbase + i, 0x0F); 109 } 110 } 111 112 /* 113 * PSC interrupt handler. It's a lot like the VIA interrupt handler. 114 */ 115 116 static void psc_irq(unsigned int irq, struct irq_desc *desc) 117 { 118 unsigned int offset = (unsigned int)irq_desc_get_handler_data(desc); 119 int pIFR = pIFRbase + offset; 120 int pIER = pIERbase + offset; 121 int irq_num; 122 unsigned char irq_bit, events; 123 124 #ifdef DEBUG_IRQS 125 printk("psc_irq: irq %u pIFR = 0x%02X pIER = 0x%02X\n", 126 irq, (int) psc_read_byte(pIFR), (int) psc_read_byte(pIER)); 127 #endif 128 129 events = psc_read_byte(pIFR) & psc_read_byte(pIER) & 0xF; 130 if (!events) 131 return; 132 133 irq_num = irq << 3; 134 irq_bit = 1; 135 do { 136 if (events & irq_bit) { 137 psc_write_byte(pIFR, irq_bit); 138 generic_handle_irq(irq_num); 139 } 140 irq_num++; 141 irq_bit <<= 1; 142 } while (events >= irq_bit); 143 } 144 145 /* 146 * Register the PSC interrupt dispatchers for autovector interrupts 3-6. 147 */ 148 149 void __init psc_register_interrupts(void) 150 { 151 irq_set_chained_handler_and_data(IRQ_AUTO_3, psc_irq, (void *)0x30); 152 irq_set_chained_handler_and_data(IRQ_AUTO_4, psc_irq, (void *)0x40); 153 irq_set_chained_handler_and_data(IRQ_AUTO_5, psc_irq, (void *)0x50); 154 irq_set_chained_handler_and_data(IRQ_AUTO_6, psc_irq, (void *)0x60); 155 } 156 157 void psc_irq_enable(int irq) { 158 int irq_src = IRQ_SRC(irq); 159 int irq_idx = IRQ_IDX(irq); 160 int pIER = pIERbase + (irq_src << 4); 161 162 #ifdef DEBUG_IRQUSE 163 printk("psc_irq_enable(%d)\n", irq); 164 #endif 165 psc_write_byte(pIER, (1 << irq_idx) | 0x80); 166 } 167 168 void psc_irq_disable(int irq) { 169 int irq_src = IRQ_SRC(irq); 170 int irq_idx = IRQ_IDX(irq); 171 int pIER = pIERbase + (irq_src << 4); 172 173 #ifdef DEBUG_IRQUSE 174 printk("psc_irq_disable(%d)\n", irq); 175 #endif 176 psc_write_byte(pIER, 1 << irq_idx); 177 } 178