make sound work

2025-08-16 23:06:15 +02:00
parent b71c83a5ca
commit f7c5959b0a
58 changed files with 25933 additions and 25820 deletions
@@ -0,0 +1,42 @@
+/* sd_spi.h
+Copyright 2021 Carl John Kugler III
+
+Licensed under the Apache License, Version 2.0 (the License); you may not use 
+this file except in compliance with the License. You may obtain a copy of the 
+License at
+
+   http://www.apache.org/licenses/LICENSE-2.0 
+Unless required by applicable law or agreed to in writing, software distributed 
+under the License is distributed on an AS IS BASIS, WITHOUT WARRANTIES OR 
+CONDITIONS OF ANY KIND, either express or implied. See the License for the 
+specific language governing permissions and limitations under the License.
+*/
+
+#ifndef _SD_SPI_H_
+#define _SD_SPI_H_
+
+#include <stdint.h>
+#include "sd_card.h"
+
+/* Transfer tx to SPI while receiving SPI to rx. 
+tx or rx can be NULL if not important. */
+bool sd_spi_transfer(sd_card_t *pSD, const uint8_t *tx, uint8_t *rx, size_t length);
+uint8_t sd_spi_write(sd_card_t *pSD, const uint8_t value);
+void sd_spi_deselect_pulse(sd_card_t *pSD);
+void sd_spi_acquire(sd_card_t *pSD);
+void sd_spi_release(sd_card_t *pSD);
+void sd_spi_go_low_frequency(sd_card_t *this);
+void sd_spi_go_high_frequency(sd_card_t *this);
+
+/* 
+After power up, the host starts the clock and sends the initializing sequence on the CMD line. 
+This sequence is a contiguous stream of logical ‘1’s. The sequence length is the maximum of 1msec, 
+74 clocks or the supply-ramp-uptime; the additional 10 clocks 
+(over the 64 clocks after what the card should be ready for communication) is
+provided to eliminate power-up synchronization problems. 
+*/
+void sd_spi_send_initializing_sequence(sd_card_t * pSD);
+
+#endif
+
+/* [] END OF FILE */