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 volatile __u8 *psc; 31 EXPORT_SYMBOL_GPL(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) 42 return; 43 44 for (i = 0x30 ; i < 0x70 ; i += 0x10) { 45 printk(KERN_DEBUG "PSC #%d: IFR = 0x%02X IER = 0x%02X\n", 46 i >> 4, 47 (int) psc_read_byte(pIFRbase + i), 48 (int) psc_read_byte(pIERbase + i)); 49 } 50 } 51 52 /* 53 * Try to kill all DMA channels on the PSC. Not sure how this his 54 * supposed to work; this is code lifted from macmace.c and then 55 * expanded to cover what I think are the other 7 channels. 56 */ 57 58 static __init void psc_dma_die_die_die(void) 59 { 60 int i; 61 62 for (i = 0 ; i < 9 ; i++) { 63 psc_write_word(PSC_CTL_BASE + (i << 4), 0x8800); 64 psc_write_word(PSC_CTL_BASE + (i << 4), 0x1000); 65 psc_write_word(PSC_CMD_BASE + (i << 5), 0x1100); 66 psc_write_word(PSC_CMD_BASE + (i << 5) + 0x10, 0x1100); 67 } 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 return; 84 } 85 86 /* 87 * The PSC is always at the same spot, but using psc 88 * keeps things consistent with the psc_xxxx functions. 89 */ 90 91 psc = (void *) PSC_BASE; 92 93 pr_debug("PSC detected at %p\n", psc); 94 95 psc_dma_die_die_die(); 96 97 #ifdef DEBUG_PSC 98 psc_debug_dump(); 99 #endif 100 /* 101 * Mask and clear all possible interrupts 102 */ 103 104 for (i = 0x30 ; i < 0x70 ; i += 0x10) { 105 psc_write_byte(pIERbase + i, 0x0F); 106 psc_write_byte(pIFRbase + i, 0x0F); 107 } 108 } 109 110 /* 111 * PSC interrupt handler. It's a lot like the VIA interrupt handler. 112 */ 113 114 static void psc_irq(struct irq_desc *desc) 115 { 116 unsigned int offset = (unsigned int)irq_desc_get_handler_data(desc); 117 unsigned int irq = irq_desc_get_irq(desc); 118 int pIFR = pIFRbase + offset; 119 int pIER = pIERbase + offset; 120 int irq_num; 121 unsigned char irq_bit, events; 122 123 events = psc_read_byte(pIFR) & psc_read_byte(pIER) & 0xF; 124 if (!events) 125 return; 126 127 irq_num = irq << 3; 128 irq_bit = 1; 129 do { 130 if (events & irq_bit) { 131 psc_write_byte(pIFR, irq_bit); 132 generic_handle_irq(irq_num); 133 } 134 irq_num++; 135 irq_bit <<= 1; 136 } while (events >= irq_bit); 137 } 138 139 /* 140 * Register the PSC interrupt dispatchers for autovector interrupts 3-6. 141 */ 142 143 void __init psc_register_interrupts(void) 144 { 145 irq_set_chained_handler_and_data(IRQ_AUTO_3, psc_irq, (void *)0x30); 146 irq_set_chained_handler_and_data(IRQ_AUTO_4, psc_irq, (void *)0x40); 147 irq_set_chained_handler_and_data(IRQ_AUTO_5, psc_irq, (void *)0x50); 148 irq_set_chained_handler_and_data(IRQ_AUTO_6, psc_irq, (void *)0x60); 149 } 150 151 void psc_irq_enable(int irq) { 152 int irq_src = IRQ_SRC(irq); 153 int irq_idx = IRQ_IDX(irq); 154 int pIER = pIERbase + (irq_src << 4); 155 156 psc_write_byte(pIER, (1 << irq_idx) | 0x80); 157 } 158 159 void psc_irq_disable(int irq) { 160 int irq_src = IRQ_SRC(irq); 161 int irq_idx = IRQ_IDX(irq); 162 int pIER = pIERbase + (irq_src << 4); 163 164 psc_write_byte(pIER, 1 << irq_idx); 165 } 166