mirror of
https://github.com/isometimes/rpi4-osdev
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60 lines
2.2 KiB
C
60 lines
2.2 KiB
C
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#include "../include/io.h"
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#define PWM_BASE (PERIPHERAL_BASE + 0x20C000 + 0x800) /* PWM1 register base address on RPi4 */
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#define PWM_LEGACY_BASE (LEGACY_BASE + 0x20C000 + 0x800) /* PWM1 register base legacy address on RPi4 */
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#define CLOCK_BASE (PERIPHERAL_BASE + 0x101000)
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#define DMA_BASE (PERIPHERAL_BASE + 0x007100) /* DMA register base address */
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#define DMA_ENABLE (DMA_BASE + 0xFF0) /* DMA global enable bits */
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#define DMA_ADDRESS 0x00500000 /* A safe address to use for our DMA transfer */
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#define BCM2711_PWMCLK_CNTL 40
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#define BCM2711_PWMCLK_DIV 41
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#define PM_PASSWORD 0x5A000000
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#define BCM2711_PWM_CONTROL 0
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#define BCM2711_PWM_STATUS 1
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#define BCM2711_PWM_DMAC 2
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#define BCM2711_PWM0_RANGE 4
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#define BCM2711_PWM0_DATA 5
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#define BCM2711_PWM_FIFO 6
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#define BCM2711_PWM1_RANGE 8
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#define BCM2711_PWM1_DATA 9
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#define BCM2711_PWM1_USEFIFO 0x2000 /* Data from FIFO */
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#define BCM2711_PWM1_ENABLE 0x0100 /* Channel enable */
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#define BCM2711_PWM0_USEFIFO 0x0020 /* Data from FIFO */
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#define BCM2711_PWM0_ENABLE 0x0001 /* Channel enable */
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#define BCM2711_PWM_ENAB 0x80000000 /* PWM DMA Configuration: DMA Enable (bit 31 set) */
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#define BCM2711_GAPO2 0x20
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#define BCM2711_GAPO1 0x10
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#define BCM2711_RERR1 0x8
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#define BCM2711_WERR1 0x4
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#define BCM2711_FULL1 0x1
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#define ERRORMASK (BCM2711_GAPO2 | BCM2711_GAPO1 | BCM2711_RERR1 | BCM2711_WERR1)
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#define DMA_CS 0 /* Control/status register offset for DMA channel 0 */
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#define DMA_CONBLK_AD 1
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#define DMA_EN1 1 << 1 /* Enable DMA engine 1 */
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#define DMA_ACTIVE 1 /* Active bit set */
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#define DMA_DEST_DREQ 0x40 /* Use DREQ to pace peripheral writes */
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#define DMA_PERMAP_1 0x10000 /* PWM1 peripheral for DREQ */
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#define DMA_SRC_INC 0x100 /* Increment source address */
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struct dma_cb {
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unsigned int ti;
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unsigned int source_ad;
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unsigned int dest_ad;
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unsigned int txfr_len;
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unsigned int stride;
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unsigned int nextconbk;
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unsigned int null1;
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unsigned int null2;
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} __attribute__((aligned(32)));
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void audio_init(void);
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void audio_play_cpu(unsigned char *data, unsigned int size);
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void audio_play_dma(unsigned char *data, unsigned int size);
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void audio_wait_dma(void);
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