From ee58278ed2502a6e9b6d2625f2fe1bf453038716 Mon Sep 17 00:00:00 2001 From: hathach Date: Thu, 27 Apr 2023 23:08:25 +0700 Subject: [PATCH] add code to calculate divisor from baudrate for ftdi --- src/class/cdc/cdc_host.c | 35 +++++++++++++++++++++++++++++------ 1 file changed, 29 insertions(+), 6 deletions(-) diff --git a/src/class/cdc/cdc_host.c b/src/class/cdc/cdc_host.c index ab1a10427..132b1ef09 100644 --- a/src/class/cdc/cdc_host.c +++ b/src/class/cdc/cdc_host.c @@ -847,13 +847,36 @@ static bool ftdi_sio_set_modem_ctrl(cdch_interface_t* p_cdc, uint16_t line_state return true; } +static uint32_t ftdi_232bm_baud_base_to_divisor(uint32_t baud, uint32_t base) +{ + const uint8_t divfrac[8] = { 0, 3, 2, 4, 1, 5, 6, 7 }; + uint32_t divisor; + + /* divisor shifted 3 bits to the left */ + uint32_t divisor3 = base / (2 * baud); + divisor = (divisor3 >> 3); + divisor |= (uint32_t) divfrac[divisor3 & 0x7] << 14; + + /* Deal with special cases for highest baud rates. */ + if (divisor == 1) { /* 1.0 */ + divisor = 0; + } + else if (divisor == 0x4001) { /* 1.5 */ + divisor = 1; + } + + return divisor; +} + +static uint32_t ftdi_232bm_baud_to_divisor(uint32_t baud) +{ + return ftdi_232bm_baud_base_to_divisor(baud, 48000000u); +} + static bool ftdi_sio_set_baudrate(cdch_interface_t* p_cdc, uint32_t baudrate, tuh_xfer_cb_t complete_cb, uintptr_t user_data) { - // TODO baudrate to baud divisor - (void) baudrate; - uint16_t divisor = 0x4138; // FIXME hardcoded to 9600 baud - - TU_LOG_CDCH("CDC FTDI Set BaudRate = %u, divisor = %u\n", baudrate, divisor); + uint16_t const divisor = (uint16_t) ftdi_232bm_baud_to_divisor(baudrate); + TU_LOG_CDCH("CDC FTDI Set BaudRate = %lu, divisor = 0x%04x\n", baudrate, divisor); p_cdc->user_control_cb = complete_cb; TU_ASSERT(ftdi_sio_set_request(p_cdc, FTDI_SIO_SET_BAUD_RATE, divisor, cdch_internal_control_complete, user_data)); @@ -985,7 +1008,7 @@ static bool cp210x_ifc_enable(cdch_interface_t* p_cdc, uint16_t enabled, tuh_xfe } static bool cp210x_set_baudrate(cdch_interface_t* p_cdc, uint32_t baudrate, tuh_xfer_cb_t complete_cb, uintptr_t user_data) { - TU_LOG_CDCH("CDC CP210x Set BaudRate = %u\n", baudrate); + TU_LOG_CDCH("CDC CP210x Set BaudRate = %lu\n", baudrate); baudrate = tu_htole32(baudrate); return cp210x_set_request(p_cdc, CP210X_SET_BAUDRATE, 0, (uint8_t *) &baudrate, 4, complete_cb, user_data); }