diff options
Diffstat (limited to 'watch-library/shared/driver/spiflash.c')
-rw-r--r-- | watch-library/shared/driver/spiflash.c | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/watch-library/shared/driver/spiflash.c b/watch-library/shared/driver/spiflash.c new file mode 100644 index 00000000..da6b2630 --- /dev/null +++ b/watch-library/shared/driver/spiflash.c @@ -0,0 +1,120 @@ +/* + * MIT License + * + * Copyright (c) 2022 Joey Castillo + * + * Ported from MIT-licensed code from CircuitPython + * Copyright (c) 2016, 2017 Scott Shawcroft for Adafruit Industries + * + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in all + * copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#include "spiflash.h" + +#define SPI_FLASH_FAST_READ false + +static void flash_enable(void) { + watch_set_pin_level(A3, false); +} + +static void flash_disable(void) { + watch_set_pin_level(A3, true); +} + +static bool transfer(uint8_t *command, uint32_t command_length, uint8_t *data_in, uint8_t *data_out, uint32_t data_length) { + bool status = watch_spi_write(command, command_length); + if (status) { + if (data_in != NULL && data_out != NULL) { + status = watch_spi_transfer(data_out, data_in, data_length); + } else if (data_out != NULL) { + status = watch_spi_read(data_out, data_length); + } else if (data_in != NULL) { + status = watch_spi_write(data_in, data_length); + } + } + flash_disable(); + return status; +} + +static bool transfer_command(uint8_t command, uint8_t *data_in, uint8_t *data_out, uint32_t data_length) { + return transfer(&command, 1, data_in, data_out, data_length); +} + +bool spi_flash_command(uint8_t command) { + return transfer_command(command, NULL, NULL, 0); +} + +bool spi_flash_read_command(uint8_t command, uint8_t *data, uint32_t data_length) { + return transfer_command(command, NULL, data, data_length); +} + +bool spi_flash_write_command(uint8_t command, uint8_t *data, uint32_t data_length) { + return transfer_command(command, data, NULL, data_length); +} + +// Pack the low 24 bits of the address into a uint8_t array. +static void address_to_bytes(uint32_t address, uint8_t *bytes) { + bytes[0] = (address >> 16) & 0xff; + bytes[1] = (address >> 8) & 0xff; + bytes[2] = address & 0xff; +} + +bool spi_flash_sector_command(uint8_t command, uint32_t address) { + uint8_t request[4] = {command, 0x00, 0x00, 0x00}; + address_to_bytes(address, request + 1); + return transfer(request, 4, NULL, NULL, 0); +} + +bool spi_flash_write_data(uint32_t address, uint8_t *data, uint32_t data_length) { + uint8_t request[4] = {CMD_PAGE_PROGRAM, 0x00, 0x00, 0x00}; + // Write the SPI flash write address into the bytes following the command byte. + address_to_bytes(address, request + 1); + flash_enable(); + bool status = watch_spi_write(request, 4); + if (status) { + status = watch_spi_write(data, data_length); + } + flash_disable(); + return status; +} + +bool spi_flash_read_data(uint32_t address, uint8_t *data, uint32_t data_length) { + uint8_t request[5] = {CMD_READ_DATA, 0x00, 0x00, 0x00}; + uint8_t command_length = 4; + if (SPI_FLASH_FAST_READ) { + request[0] = CMD_FAST_READ_DATA; + command_length = 5; + } + // Write the SPI flash read address into the bytes following the command byte. + address_to_bytes(address, request + 1); + flash_enable(); + bool status = watch_spi_write(request, command_length); + if (status) { + status = watch_spi_read(data, data_length); + } + flash_disable(); + return status; +} + +void spi_flash_init(void) { + gpio_set_pin_level(A3, true); + gpio_set_pin_direction(A3, GPIO_DIRECTION_OUT); + watch_enable_spi(); +} |