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 EXPORT_SYMBOL_GPL(psc); 33 34 /* 35 * Debugging dump, used in various places to see what's going on. 36 */ 37 38 static void psc_debug_dump(void) 39 { 40 int i; 41 42 if (!psc_present) return; 43 for (i = 0x30 ; i < 0x70 ; i += 0x10) { 44 printk("PSC #%d: IFR = 0x%02X IER = 0x%02X\n", 45 i >> 4, 46 (int) psc_read_byte(pIFRbase + i), 47 (int) psc_read_byte(pIERbase + i)); 48 } 49 } 50 51 /* 52 * Try to kill all DMA channels on the PSC. Not sure how this his 53 * supposed to work; this is code lifted from macmace.c and then 54 * expanded to cover what I think are the other 7 channels. 55 */ 56 57 static __init void psc_dma_die_die_die(void) 58 { 59 int i; 60 61 printk("Killing all PSC DMA channels..."); 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 printk("done!\n"); 69 } 70 71 /* 72 * Initialize the PSC. For now this just involves shutting down all 73 * interrupt sources using the IERs. 74 */ 75 76 void __init psc_init(void) 77 { 78 int i; 79 80 if (macintosh_config->ident != MAC_MODEL_C660 81 && macintosh_config->ident != MAC_MODEL_Q840) 82 { 83 psc = NULL; 84 psc_present = 0; 85 return; 86 } 87 88 /* 89 * The PSC is always at the same spot, but using psc 90 * keeps things consistent with the psc_xxxx functions. 91 */ 92 93 psc = (void *) PSC_BASE; 94 psc_present = 1; 95 96 printk("PSC detected at %p\n", psc); 97 98 psc_dma_die_die_die(); 99 100 #ifdef DEBUG_PSC 101 psc_debug_dump(); 102 #endif 103 /* 104 * Mask and clear all possible interrupts 105 */ 106 107 for (i = 0x30 ; i < 0x70 ; i += 0x10) { 108 psc_write_byte(pIERbase + i, 0x0F); 109 psc_write_byte(pIFRbase + i, 0x0F); 110 } 111 } 112 113 /* 114 * PSC interrupt handler. It's a lot like the VIA interrupt handler. 115 */ 116 117 static void psc_irq(struct irq_desc *desc) 118 { 119 unsigned int offset = (unsigned int)irq_desc_get_handler_data(desc); 120 unsigned int irq = irq_desc_get_irq(desc); 121 int pIFR = pIFRbase + offset; 122 int pIER = pIERbase + offset; 123 int irq_num; 124 unsigned char irq_bit, events; 125 126 #ifdef DEBUG_IRQS 127 printk("psc_irq: irq %u pIFR = 0x%02X pIER = 0x%02X\n", 128 irq, (int) psc_read_byte(pIFR), (int) psc_read_byte(pIER)); 129 #endif 130 131 events = psc_read_byte(pIFR) & psc_read_byte(pIER) & 0xF; 132 if (!events) 133 return; 134 135 irq_num = irq << 3; 136 irq_bit = 1; 137 do { 138 if (events & irq_bit) { 139 psc_write_byte(pIFR, irq_bit); 140 generic_handle_irq(irq_num); 141 } 142 irq_num++; 143 irq_bit <<= 1; 144 } while (events >= irq_bit); 145 } 146 147 /* 148 * Register the PSC interrupt dispatchers for autovector interrupts 3-6. 149 */ 150 151 void __init psc_register_interrupts(void) 152 { 153 irq_set_chained_handler_and_data(IRQ_AUTO_3, psc_irq, (void *)0x30); 154 irq_set_chained_handler_and_data(IRQ_AUTO_4, psc_irq, (void *)0x40); 155 irq_set_chained_handler_and_data(IRQ_AUTO_5, psc_irq, (void *)0x50); 156 irq_set_chained_handler_and_data(IRQ_AUTO_6, psc_irq, (void *)0x60); 157 } 158 159 void psc_irq_enable(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 #ifdef DEBUG_IRQUSE 165 printk("psc_irq_enable(%d)\n", irq); 166 #endif 167 psc_write_byte(pIER, (1 << irq_idx) | 0x80); 168 } 169 170 void psc_irq_disable(int irq) { 171 int irq_src = IRQ_SRC(irq); 172 int irq_idx = IRQ_IDX(irq); 173 int pIER = pIERbase + (irq_src << 4); 174 175 #ifdef DEBUG_IRQUSE 176 printk("psc_irq_disable(%d)\n", irq); 177 #endif 178 psc_write_byte(pIER, 1 << irq_idx); 179 } 180