mbed library sources modified for open wear
Dependents: openwear-lifelogger-example
Fork of mbed-src by
targets/hal/TARGET_NXP/TARGET_LPC11U6X/serial_api.c
- Committer:
- janekm
- Date:
- 2014-09-16
- Revision:
- 310:6188e0254baa
- Parent:
- 227:7bd0639b8911
File content as of revision 310:6188e0254baa:
/* mbed Microcontroller Library * Copyright (c) 2006-2013 ARM Limited * * 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. */ // math.h required for floating point operations for baud rate calculation #include "mbed_assert.h" #include <math.h> #include <string.h> #include <stdlib.h> #include "serial_api.h" #include "cmsis.h" #include "pinmap.h" #if DEVICE_SERIAL /****************************************************************************** * INITIALIZATION ******************************************************************************/ #define UART_NUM 5 // CFG #define UART_EN (0x01<<0) // CTL #define TXBRKEN (0x01<<1) // STAT #define RXRDY (0x01<<0) #define TXRDY (0x01<<2) #define DELTACTS (0x01<<5) #define RXBRK (0x01<<10) #define DELTARXBRK (0x01<<11) static const PinMap PinMap_UART_TX[] = { {P0_19, UART_0, 1}, {P1_18, UART_0, 2}, {P1_27, UART_0, 2}, {P1_8 , UART_1, 2}, {P1_0 , UART_2, 3}, {P1_23, UART_2, 3}, {P2_4 , UART_3, 1}, {P2_12, UART_4, 1}, { NC , NC , 0} }; static const PinMap PinMap_UART_RX[] = { {P0_18, UART_0, 1}, {P1_17, UART_0, 2}, {P1_26, UART_0, 2}, {P1_2 , UART_1, 3}, {P0_20, UART_2, 2}, {P1_6 , UART_2, 2}, {P2_3 , UART_3, 1}, {P2_11, UART_4, 1}, {NC , NC , 0} }; static uint32_t serial_irq_ids[UART_NUM] = {0}; static uart_irq_handler irq_handler; int stdio_uart_inited = 0; serial_t stdio_uart; void serial_init(serial_t *obj, PinName tx, PinName rx) { int is_stdio_uart = 0; // determine the UART to use UARTName uart_tx = (UARTName)pinmap_peripheral(tx, PinMap_UART_TX); UARTName uart_rx = (UARTName)pinmap_peripheral(rx, PinMap_UART_RX); UARTName uart = (UARTName)pinmap_merge(uart_tx, uart_rx); MBED_ASSERT((int)uart != NC); switch (uart) { case UART_0: obj->index = 0; LPC_SYSCON->SYSAHBCLKCTRL |= (1 << 12); break; case UART_1: obj->index = 1; LPC_SYSCON->SYSAHBCLKCTRL |= (1 << 20); LPC_SYSCON->PRESETCTRL |= (1 << 5); break; case UART_2: obj->index = 2; LPC_SYSCON->SYSAHBCLKCTRL |= (1 << 21); LPC_SYSCON->PRESETCTRL |= (1 << 6); break; case UART_3: obj->index = 3; LPC_SYSCON->SYSAHBCLKCTRL |= (1 << 22); LPC_SYSCON->PRESETCTRL |= (1 << 7); break; case UART_4: obj->index = 4; LPC_SYSCON->SYSAHBCLKCTRL |= (1 << 22); LPC_SYSCON->PRESETCTRL |= (1 << 8); break; } if (obj->index == 0) obj->uart = (LPC_USART0_Type *)uart; else obj->mini_uart = (LPC_USART4_Type *)uart; if (obj->index == 0) { // enable fifos and default rx trigger level obj->uart->FCR = 1 << 0 // FIFO Enable - 0 = Disables, 1 = Enabled | 0 << 1 // Rx Fifo Clear | 0 << 2 // Tx Fifo Clear | 0 << 6; // Rx irq trigger level - 0 = 1 char, 1 = 4 chars, 2 = 8 chars, 3 = 14 chars // disable irqs obj->uart->IER = 0 << 0 // Rx Data available irq enable | 0 << 1 // Tx Fifo empty irq enable | 0 << 2; // Rx Line Status irq enable } else { // Clear all status bits obj->mini_uart->STAT = (DELTACTS | DELTARXBRK); // Enable UART obj->mini_uart->CFG |= UART_EN; } // set default baud rate and format serial_baud (obj, 9600); serial_format(obj, 8, ParityNone, 1); // pinout the chosen uart pinmap_pinout(tx, PinMap_UART_TX); pinmap_pinout(rx, PinMap_UART_RX); // set rx/tx pins in PullUp mode pin_mode(tx, PullUp); pin_mode(rx, PullUp); is_stdio_uart = (uart == STDIO_UART) ? (1) : (0); if (is_stdio_uart && (obj->index == 0)) { stdio_uart_inited = 1; memcpy(&stdio_uart, obj, sizeof(serial_t)); } } void serial_free(serial_t *obj) { serial_irq_ids[obj->index] = 0; } // serial_baud // set the baud rate, taking in to account the current SystemFrequency void serial_baud(serial_t *obj, int baudrate) { LPC_SYSCON->USART0CLKDIV = 1; LPC_SYSCON->FRGCLKDIV = 1; if (obj->index == 0) { uint32_t PCLK = SystemCoreClock; // First we check to see if the basic divide with no DivAddVal/MulVal // ratio gives us an integer result. If it does, we set DivAddVal = 0, // MulVal = 1. Otherwise, we search the valid ratio value range to find // the closest match. This could be more elegant, using search methods // and/or lookup tables, but the brute force method is not that much // slower, and is more maintainable. uint16_t DL = PCLK / (16 * baudrate); uint8_t DivAddVal = 0; uint8_t MulVal = 1; int hit = 0; uint16_t dlv; uint8_t mv, dav; if ((PCLK % (16 * baudrate)) != 0) { // Checking for zero remainder int err_best = baudrate, b; for (mv = 1; mv < 16 && !hit; mv++) { for (dav = 0; dav < mv; dav++) { // baudrate = PCLK / (16 * dlv * (1 + (DivAdd / Mul)) // solving for dlv, we get dlv = mul * PCLK / (16 * baudrate * (divadd + mul)) // mul has 4 bits, PCLK has 27 so we have 1 bit headroom which can be used for rounding // for many values of mul and PCLK we have 2 or more bits of headroom which can be used to improve precision // note: X / 32 doesn't round correctly. Instead, we use ((X / 16) + 1) / 2 for correct rounding if ((mv * PCLK * 2) & 0x80000000) // 1 bit headroom dlv = ((((2 * mv * PCLK) / (baudrate * (dav + mv))) / 16) + 1) / 2; else // 2 bits headroom, use more precision dlv = ((((4 * mv * PCLK) / (baudrate * (dav + mv))) / 32) + 1) / 2; // datasheet says if DLL==DLM==0, then 1 is used instead since divide by zero is ungood if (dlv == 0) dlv = 1; // datasheet says if dav > 0 then DL must be >= 2 if ((dav > 0) && (dlv < 2)) dlv = 2; // integer rearrangement of the baudrate equation (with rounding) b = ((PCLK * mv / (dlv * (dav + mv) * 8)) + 1) / 2; // check to see how we went b = abs(b - baudrate); if (b < err_best) { err_best = b; DL = dlv; MulVal = mv; DivAddVal = dav; if (b == baudrate) { hit = 1; break; } } } } } // set LCR[DLAB] to enable writing to divider registers obj->uart->LCR |= (1 << 7); // set divider values obj->uart->DLM = (DL >> 8) & 0xFF; obj->uart->DLL = (DL >> 0) & 0xFF; obj->uart->FDR = (uint32_t) DivAddVal << 0 | (uint32_t) MulVal << 4; // clear LCR[DLAB] obj->uart->LCR &= ~(1 << 7); } else { uint32_t UARTSysClk = SystemCoreClock / LPC_SYSCON->FRGCLKDIV; obj->mini_uart->BRG = UARTSysClk / 16 / baudrate - 1; LPC_SYSCON->UARTFRGDIV = 0xFF; LPC_SYSCON->UARTFRGMULT = ( ((UARTSysClk / 16) * (LPC_SYSCON->UARTFRGDIV + 1)) / (baudrate * (obj->mini_uart->BRG + 1)) ) - (LPC_SYSCON->UARTFRGDIV + 1); } } void serial_format(serial_t *obj, int data_bits, SerialParity parity, int stop_bits) { MBED_ASSERT((stop_bits == 1) || (stop_bits == 2)); // 0: 1 stop bits, 1: 2 stop bits stop_bits -= 1; if (obj->index == 0) { MBED_ASSERT((data_bits > 4) && (data_bits < 9)); // 0: 5 data bits ... 3: 8 data bits MBED_ASSERT((parity == ParityNone) || (parity == ParityOdd) || (parity == ParityEven) || (parity == ParityForced1) || (parity == ParityForced0)); data_bits -= 5; int parity_enable, parity_select; switch (parity) { case ParityNone: parity_enable = 0; parity_select = 0; break; case ParityOdd : parity_enable = 1; parity_select = 0; break; case ParityEven: parity_enable = 1; parity_select = 1; break; case ParityForced1: parity_enable = 1; parity_select = 2; break; case ParityForced0: parity_enable = 1; parity_select = 3; break; default: return; } obj->uart->LCR = data_bits << 0 | stop_bits << 2 | parity_enable << 3 | parity_select << 4; } else { // 0: 7 data bits ... 2: 9 data bits MBED_ASSERT((data_bits > 6) && (data_bits < 10)); MBED_ASSERT((parity == ParityNone) || (parity == ParityOdd) || (parity == ParityEven)); data_bits -= 7; int paritysel; switch (parity) { case ParityNone: paritysel = 0; break; case ParityEven: paritysel = 2; break; case ParityOdd : paritysel = 3; break; default: return; } obj->mini_uart->CFG = (data_bits << 2) | (paritysel << 4) | (stop_bits << 6) | UART_EN; } } /****************************************************************************** * INTERRUPTS HANDLING ******************************************************************************/ static inline void uart_irq(uint32_t iir, uint32_t index) { SerialIrq irq_type; switch (iir) { case 1: irq_type = TxIrq; break; case 2: irq_type = RxIrq; break; default: return; } if (serial_irq_ids[index] != 0) irq_handler(serial_irq_ids[index], irq_type); } void uart0_irq() { uart_irq((LPC_USART0->IIR >> 1) & 0x7, 0); } void uart1_irq() { uart_irq((LPC_USART1->STAT & (1 << 2)) ? 2 : 1, 1); } void uart2_irq() { uart_irq((LPC_USART1->STAT & (1 << 2)) ? 2 : 1, 2); } void uart3_irq() { uart_irq((LPC_USART1->STAT & (1 << 2)) ? 2 : 1, 3); } void uart4_irq() { uart_irq((LPC_USART1->STAT & (1 << 2)) ? 2 : 1, 4); } void serial_irq_handler(serial_t *obj, uart_irq_handler handler, uint32_t id) { irq_handler = handler; serial_irq_ids[obj->index] = id; } void serial_irq_set(serial_t *obj, SerialIrq irq, uint32_t enable) { IRQn_Type irq_n = (IRQn_Type)0; uint32_t vector = 0; switch ((int)obj->uart) { case UART_0: irq_n = USART0_IRQn; vector = (uint32_t)&uart0_irq; break; case UART_1: irq_n = USART1_4_IRQn; vector = (uint32_t)&uart1_irq; break; case UART_2: irq_n = USART2_3_IRQn; vector = (uint32_t)&uart2_irq; break; case UART_3: irq_n = USART2_3_IRQn; vector = (uint32_t)&uart3_irq; break; case UART_4: irq_n = USART1_4_IRQn; vector = (uint32_t)&uart4_irq; break; } if (enable) { if (obj->index == 0) { obj->uart->IER |= (1 << irq); } else { obj->mini_uart->INTENSET = (1 << ((irq == RxIrq) ? 0 : 2)); } NVIC_SetVector(irq_n, vector); NVIC_EnableIRQ(irq_n); } else { // disable int all_disabled = 0; SerialIrq other_irq = (irq == RxIrq) ? (TxIrq) : (RxIrq); if (obj->index == 0) { obj->uart->IER &= ~(1 << irq); all_disabled = (obj->uart->IER & (1 << other_irq)) == 0; } else { obj->mini_uart->INTENSET &= ~(1 << ((irq == RxIrq) ? 0 : 2)); all_disabled = (obj->mini_uart->INTENSET & (1 << ((other_irq == RxIrq) ? 0 : 2))) == 0; } if (all_disabled) NVIC_DisableIRQ(irq_n); } } /****************************************************************************** * READ/WRITE ******************************************************************************/ int serial_getc(serial_t *obj) { while (!serial_readable(obj)); if (obj->index == 0) { return obj->uart->RBR; } else { return obj->mini_uart->RXDAT; } } void serial_putc(serial_t *obj, int c) { while (!serial_writable(obj)); if (obj->index == 0) { obj->uart->THR = c; } else { obj->mini_uart->TXDAT = c; } } int serial_readable(serial_t *obj) { if (obj->index == 0) { return obj->uart->LSR & 0x01; } else { return obj->mini_uart->STAT & RXRDY; } } int serial_writable(serial_t *obj) { if (obj->index == 0) { return obj->uart->LSR & 0x20; } else { return obj->mini_uart->STAT & TXRDY; } } void serial_clear(serial_t *obj) { if (obj->index == 0) { obj->uart->FCR = 1 << 1 // rx FIFO reset | 1 << 2 // tx FIFO reset | 0 << 6; // interrupt depth } else { obj->mini_uart->STAT = 0; } } void serial_pinout_tx(PinName tx) { pinmap_pinout(tx, PinMap_UART_TX); } void serial_break_set(serial_t *obj) { if (obj->index == 0) { obj->uart->LCR |= (1 << 6); } else { obj->mini_uart->CTL |= TXBRKEN; } } void serial_break_clear(serial_t *obj) { if (obj->index == 0) { obj->uart->LCR &= ~(1 << 6); } else { obj->mini_uart->CTL &= ~TXBRKEN; } } #endif