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/* gic.c — GIC-400 driver for Raspberry Pi 5 */ |
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#include "gic.h" |
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void gic_init(void) { |
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/* Disable distributor */ |
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GICD_CTLR = 0; |
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/* Get number of IRQs supported */ |
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int n = ((GICD_TYPER & 0x1F) + 1) * 32; |
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/* Disable all IRQs */ |
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for (int i = 0; i < n / 32; i++) { |
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GICD_ICENABLER(i) = 0xFFFFFFFF; |
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GICD_ICACTIVER(i) = 0xFFFFFFFF; |
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} |
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/* Set all IRQs to lowest priority */ |
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for (int i = 0; i < n / 4; i++) { |
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GICD_IPRIORITYR(i) = 0xA0A0A0A0; |
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} |
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/* Target all SPIs to CPU 0 */ |
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for (int i = 8; i < n / 4; i++) { |
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GICD_ITARGETSR(i) = 0x01010101; /* CPU 0 */ |
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} |
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/* All IRQs level-triggered */ |
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for (int i = 0; i < n / 16; i++) { |
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GICD_ICFGR(i) = 0; |
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} |
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/* Enable distributor */ |
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GICD_CTLR = 1; |
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/* Set CPU interface priority mask to accept all */ |
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GICC_PMR = 0xFF; |
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/* Enable CPU interface */ |
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GICC_CTLR = 1; |
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} |
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void gic_enable_irq(int irq) { |
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GICD_ISENABLER(irq / 32) = (1U << (irq % 32)); |
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} |
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void gic_disable_irq(int irq) { |
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GICD_ICENABLER(irq / 32) = (1U << (irq % 32)); |
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} |
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int gic_acknowledge(void) { |
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return (int)(GICC_IAR & 0x3FF); |
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} |
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void gic_eoi(int irq) { |
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GICC_EOIR = (uint32_t)irq; |
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} |
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