diff options
Diffstat (limited to 'tmk_core/tool/mbed/mbed-sdk/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC176X/serial_api.c')
| -rw-r--r-- | tmk_core/tool/mbed/mbed-sdk/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC176X/serial_api.c | 443 |
1 files changed, 443 insertions, 0 deletions
diff --git a/tmk_core/tool/mbed/mbed-sdk/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC176X/serial_api.c b/tmk_core/tool/mbed/mbed-sdk/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC176X/serial_api.c new file mode 100644 index 0000000000..32da943249 --- /dev/null +++ b/tmk_core/tool/mbed/mbed-sdk/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC176X/serial_api.c @@ -0,0 +1,443 @@ +/* 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" +#include "gpio_api.h" + +/****************************************************************************** + * INITIALIZATION + ******************************************************************************/ +#define UART_NUM 4 + +static const PinMap PinMap_UART_TX[] = { + {P0_0, UART_3, 2}, + {P0_2, UART_0, 1}, + {P0_10, UART_2, 1}, + {P0_15, UART_1, 1}, + {P0_25, UART_3, 3}, + {P2_0 , UART_1, 2}, + {P2_8 , UART_2, 2}, + {P4_28, UART_3, 3}, + {NC , NC , 0} +}; + +static const PinMap PinMap_UART_RX[] = { + {P0_1 , UART_3, 2}, + {P0_3 , UART_0, 1}, + {P0_11, UART_2, 1}, + {P0_16, UART_1, 1}, + {P0_26, UART_3, 3}, + {P2_1 , UART_1, 2}, + {P2_9 , UART_2, 2}, + {P4_29, UART_3, 3}, + {NC , NC , 0} +}; + +static const PinMap PinMap_UART_RTS[] = { + {P0_22, UART_1, 1}, + {P2_7, UART_1, 2}, + {NC, NC, 0} +}; + +static const PinMap PinMap_UART_CTS[] = { + {P0_17, UART_1, 1}, + {P2_2, UART_1, 2}, + {NC, NC, 0} +}; + +#define UART_MCR_RTSEN_MASK (1 << 6) +#define UART_MCR_CTSEN_MASK (1 << 7) +#define UART_MCR_FLOWCTRL_MASK (UART_MCR_RTSEN_MASK | UART_MCR_CTSEN_MASK) + +static uart_irq_handler irq_handler; + +int stdio_uart_inited = 0; +serial_t stdio_uart; + +struct serial_global_data_s { + uint32_t serial_irq_id; + gpio_t sw_rts, sw_cts; + uint8_t count, rx_irq_set_flow, rx_irq_set_api; +}; + +static struct serial_global_data_s uart_data[UART_NUM]; + +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); + + obj->uart = (LPC_UART_TypeDef *)uart; + // enable power + switch (uart) { + case UART_0: LPC_SC->PCONP |= 1 << 3; break; + case UART_1: LPC_SC->PCONP |= 1 << 4; break; + case UART_2: LPC_SC->PCONP |= 1 << 24; break; + case UART_3: LPC_SC->PCONP |= 1 << 25; break; + } + + // enable fifos and default rx trigger level + obj->uart->FCR = 1 << 0 // FIFO Enable - 0 = Disables, 1 = Enabled + | 0 << 1 // Rx Fifo Reset + | 0 << 2 // Tx Fifo Reset + | 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 + + // 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 + if (tx != NC) { + pin_mode(tx, PullUp); + } + if (rx != NC) { + pin_mode(rx, PullUp); + } + + switch (uart) { + case UART_0: obj->index = 0; break; + case UART_1: obj->index = 1; break; + case UART_2: obj->index = 2; break; + case UART_3: obj->index = 3; break; + } + uart_data[obj->index].sw_rts.pin = NC; + uart_data[obj->index].sw_cts.pin = NC; + serial_set_flow_control(obj, FlowControlNone, NC, NC); + + is_stdio_uart = (uart == STDIO_UART) ? (1) : (0); + + if (is_stdio_uart) { + stdio_uart_inited = 1; + memcpy(&stdio_uart, obj, sizeof(serial_t)); + } +} + +void serial_free(serial_t *obj) { + uart_data[obj->index].serial_irq_id = 0; +} + +// serial_baud +// set the baud rate, taking in to account the current SystemFrequency +void serial_baud(serial_t *obj, int baudrate) { + MBED_ASSERT((int)obj->uart <= UART_3); + // The LPC2300 and LPC1700 have a divider and a fractional divider to control the + // baud rate. The formula is: + // + // Baudrate = (1 / PCLK) * 16 * DL * (1 + DivAddVal / MulVal) + // where: + // 1 < MulVal <= 15 + // 0 <= DivAddVal < 14 + // DivAddVal < MulVal + // + // set pclk to /1 + switch ((int)obj->uart) { + case UART_0: LPC_SC->PCLKSEL0 &= ~(0x3 << 6); LPC_SC->PCLKSEL0 |= (0x1 << 6); break; + case UART_1: LPC_SC->PCLKSEL0 &= ~(0x3 << 8); LPC_SC->PCLKSEL0 |= (0x1 << 8); break; + case UART_2: LPC_SC->PCLKSEL1 &= ~(0x3 << 16); LPC_SC->PCLKSEL1 |= (0x1 << 16); break; + case UART_3: LPC_SC->PCLKSEL1 &= ~(0x3 << 18); LPC_SC->PCLKSEL1 |= (0x1 << 18); break; + default: break; + } + + 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); +} + +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 + 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)); + + stop_bits -= 1; + 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: + parity_enable = 0, parity_select = 0; + break; + } + + obj->uart->LCR = data_bits << 0 + | stop_bits << 2 + | parity_enable << 3 + | parity_select << 4; +} + +/****************************************************************************** + * INTERRUPTS HANDLING + ******************************************************************************/ +static inline void uart_irq(uint32_t iir, uint32_t index, LPC_UART_TypeDef *puart) { + // [Chapter 14] LPC17xx UART0/2/3: UARTn Interrupt Handling + SerialIrq irq_type; + switch (iir) { + case 1: irq_type = TxIrq; break; + case 2: irq_type = RxIrq; break; + default: return; + } + if ((RxIrq == irq_type) && (NC != uart_data[index].sw_rts.pin)) { + gpio_write(&uart_data[index].sw_rts, 1); + // Disable interrupt if it wasn't enabled by other part of the application + if (!uart_data[index].rx_irq_set_api) + puart->IER &= ~(1 << RxIrq); + } + if (uart_data[index].serial_irq_id != 0) + if ((irq_type != RxIrq) || (uart_data[index].rx_irq_set_api)) + irq_handler(uart_data[index].serial_irq_id, irq_type); +} + +void uart0_irq() {uart_irq((LPC_UART0->IIR >> 1) & 0x7, 0, (LPC_UART_TypeDef*)LPC_UART0);} +void uart1_irq() {uart_irq((LPC_UART1->IIR >> 1) & 0x7, 1, (LPC_UART_TypeDef*)LPC_UART1);} +void uart2_irq() {uart_irq((LPC_UART2->IIR >> 1) & 0x7, 2, (LPC_UART_TypeDef*)LPC_UART2);} +void uart3_irq() {uart_irq((LPC_UART3->IIR >> 1) & 0x7, 3, (LPC_UART_TypeDef*)LPC_UART3);} + +void serial_irq_handler(serial_t *obj, uart_irq_handler handler, uint32_t id) { + irq_handler = handler; + uart_data[obj->index].serial_irq_id = id; +} + +static void serial_irq_set_internal(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=UART0_IRQn; vector = (uint32_t)&uart0_irq; break; + case UART_1: irq_n=UART1_IRQn; vector = (uint32_t)&uart1_irq; break; + case UART_2: irq_n=UART2_IRQn; vector = (uint32_t)&uart2_irq; break; + case UART_3: irq_n=UART3_IRQn; vector = (uint32_t)&uart3_irq; break; + } + + if (enable) { + obj->uart->IER |= 1 << irq; + NVIC_SetVector(irq_n, vector); + NVIC_EnableIRQ(irq_n); + } else if ((TxIrq == irq) || (uart_data[obj->index].rx_irq_set_api + uart_data[obj->index].rx_irq_set_flow == 0)) { // disable + int all_disabled = 0; + SerialIrq other_irq = (irq == RxIrq) ? (TxIrq) : (RxIrq); + obj->uart->IER &= ~(1 << irq); + all_disabled = (obj->uart->IER & (1 << other_irq)) == 0; + if (all_disabled) + NVIC_DisableIRQ(irq_n); + } +} + +void serial_irq_set(serial_t *obj, SerialIrq irq, uint32_t enable) { + if (RxIrq == irq) + uart_data[obj->index].rx_irq_set_api = enable; + serial_irq_set_internal(obj, irq, enable); +} + +static void serial_flow_irq_set(serial_t *obj, uint32_t enable) { + uart_data[obj->index].rx_irq_set_flow = enable; + serial_irq_set_internal(obj, RxIrq, enable); +} + +/****************************************************************************** + * READ/WRITE + ******************************************************************************/ +int serial_getc(serial_t *obj) { + while (!serial_readable(obj)); + int data = obj->uart->RBR; + if (NC != uart_data[obj->index].sw_rts.pin) { + gpio_write(&uart_data[obj->index].sw_rts, 0); + obj->uart->IER |= 1 << RxIrq; + } + return data; +} + +void serial_putc(serial_t *obj, int c) { + while (!serial_writable(obj)); + obj->uart->THR = c; + uart_data[obj->index].count++; +} + +int serial_readable(serial_t *obj) { + return obj->uart->LSR & 0x01; +} + +int serial_writable(serial_t *obj) { + int isWritable = 1; + if (NC != uart_data[obj->index].sw_cts.pin) + isWritable = (gpio_read(&uart_data[obj->index].sw_cts) == 0) && (obj->uart->LSR & 0x40); //If flow control: writable if CTS low + UART done + else { + if (obj->uart->LSR & 0x20) + uart_data[obj->index].count = 0; + else if (uart_data[obj->index].count >= 16) + isWritable = 0; + } + return isWritable; +} + +void serial_clear(serial_t *obj) { + obj->uart->FCR = 1 << 0 // FIFO Enable - 0 = Disables, 1 = Enabled + | 1 << 1 // rx FIFO reset + | 1 << 2 // tx FIFO reset + | 0 << 6; // interrupt depth +} + +void serial_pinout_tx(PinName tx) { + pinmap_pinout(tx, PinMap_UART_TX); +} + +void serial_break_set(serial_t *obj) { + obj->uart->LCR |= (1 << 6); +} + +void serial_break_clear(serial_t *obj) { + obj->uart->LCR &= ~(1 << 6); +} + +void serial_set_flow_control(serial_t *obj, FlowControl type, PinName rxflow, PinName txflow) { + // Only UART1 has hardware flow control on LPC176x + LPC_UART1_TypeDef *uart1 = (uint32_t)obj->uart == (uint32_t)LPC_UART1 ? LPC_UART1 : NULL; + int index = obj->index; + + // First, disable flow control completely + if (uart1) + uart1->MCR = uart1->MCR & ~UART_MCR_FLOWCTRL_MASK; + uart_data[index].sw_rts.pin = uart_data[index].sw_cts.pin = NC; + serial_flow_irq_set(obj, 0); + if (FlowControlNone == type) + return; + // Check type(s) of flow control to use + UARTName uart_rts = (UARTName)pinmap_find_peripheral(rxflow, PinMap_UART_RTS); + UARTName uart_cts = (UARTName)pinmap_find_peripheral(txflow, PinMap_UART_CTS); + if (((FlowControlCTS == type) || (FlowControlRTSCTS == type)) && (NC != txflow)) { + // Can this be enabled in hardware? + if ((UART_1 == uart_cts) && (NULL != uart1)) { + // Enable auto-CTS mode + uart1->MCR |= UART_MCR_CTSEN_MASK; + pinmap_pinout(txflow, PinMap_UART_CTS); + } else { + // Can't enable in hardware, use software emulation + gpio_init_in(&uart_data[index].sw_cts, txflow); + } + } + if (((FlowControlRTS == type) || (FlowControlRTSCTS == type)) && (NC != rxflow)) { + // Enable FIFOs, trigger level of 1 char on RX FIFO + obj->uart->FCR = 1 << 0 // FIFO Enable - 0 = Disables, 1 = Enabled + | 1 << 1 // Rx Fifo Reset + | 1 << 2 // Tx Fifo Reset + | 0 << 6; // Rx irq trigger level - 0 = 1 char, 1 = 4 chars, 2 = 8 chars, 3 = 14 chars + // Can this be enabled in hardware? + if ((UART_1 == uart_rts) && (NULL != uart1)) { + // Enable auto-RTS mode + uart1->MCR |= UART_MCR_RTSEN_MASK; + pinmap_pinout(rxflow, PinMap_UART_RTS); + } else { // can't enable in hardware, use software emulation + gpio_init_out_ex(&uart_data[index].sw_rts, rxflow, 0); + // Enable RX interrupt + serial_flow_irq_set(obj, 1); + } + } +} + |