/**************************************************************************** * arch/arm/src/efm32/efm32_lowputc.c * * Copyright (C) 2014 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * 3. Neither the name NuttX nor the names of its contributors may be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include "up_arch.h" #include "chip/efm32_memorymap.h" #include "chip/efm32_usart.h" #include "chip/efm32_leuart.h" #include "chip/efm32_cmu.h" #include "efm32_lowputc.h" /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ /* Console U[S]ART base address */ #if defined(HAVE_UART_CONSOLE) # if defined(CONFIG_USART0_SERIAL_CONSOLE) # define CONSOLE_BASE EFM32_USART0_BASE # define CONSOLE_BAUD CONFIG_USART0_BAUD # define CONSOLE_PARITY CONFIG_USART0_PARITY # define CONSOLE_NBITS CONFIG_UART0_BITS # define CONSOLE_2STOP CONFIG_UART0_2STOP # elif defined(CONFIG_USART1_SERIAL_CONSOLE) # define CONSOLE_BASE EFM32_USART1_BASE # define CONSOLE_BAUD CONFIG_USART1_BAUD # define CONSOLE_PARITY CONFIG_USART1_PARITY # define CONSOLE_NBITS CONFIG_UART1_BITS # define CONSOLE_2STOP CONFIG_UART1_2STOP # elif defined(CONFIG_USART2_SERIAL_CONSOLE) # define CONSOLE_BASE EFM32_USART2_BASE # define CONSOLE_BAUD CONFIG_USART2_BAUD # define CONSOLE_PARITY CONFIG_USART2_PARITY # define CONSOLE_NBITS CONFIG_UART2_BITS # define CONSOLE_2STOP CONFIG_UART2_2STOP # elif defined(CONFIG_UART0_SERIAL_CONSOLE) # define CONSOLE_BASE EFM32_UART0_BASE # define CONSOLE_BAUD CONFIG_UART0_BAUD # define CONSOLE_PARITY CONFIG_UART0_PARITY # define CONSOLE_NBITS CONFIG_UART0_BITS # define CONSOLE_2STOP CONFIG_UART0_2STOP # elif defined(CONFIG_UART1_SERIAL_CONSOLE) # define CONSOLE_BASE EFM32_UART1_BASE # define CONSOLE_BAUD CONFIG_UART1_BAUD # define CONSOLE_PARITY CONFIG_UART1_PARITY # define CONSOLE_NBITS CONFIG_UART1_BITS # define CONSOLE_2STOP CONFIG_UART1_2STOP # else # error No U[S]ART console is selected???? Internal craziness!!! # endif #elif defined(HAVE_LEUART_CONSOLE) # if defined(CONFIG_LEUART0_SERIAL_CONSOLE) # define CONSOLE_BASE EFM32_LEUART0_BASE # define CONSOLE_BAUD CONFIG_LEUART0_BAUD # define CONSOLE_PARITY CONFIG_LEUART0_PARITY # define CONSOLE_NBITS CONFIG_LEUART0_BITS # define CONSOLE_2STOP CONFIG_LEUART0_2STOP # elif defined(CONFIG_LEUART1_SERIAL_CONSOLE) # define CONSOLE_BASE EFM32_LEUART1_BASE # define CONSOLE_BAUD CONFIG_LEUART1_BAUD # define CONSOLE_PARITY CONFIG_LEUART1_PARITY # define CONSOLE_NBITS CONFIG_LEUART1_BITS # define CONSOLE_2STOP CONFIG_LEUART1_2STOP # else # error No U[S]ART console is selected???? Internal craziness!!! # endif #endif /* HAVE_UART_CONSOLE */ /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: efm32_uart_setbaud * * Description: * Set optimal oversampling and set the baud for this U[S]ART. * ****************************************************************************/ #ifdef HAVE_UART_DEVICE static void efm32_uart_setbaud(uintptr_t base, uint32_t baud) { uint64_t clkdiv; uint64_t maxover; uint32_t oversample; uint32_t regval; uint32_t ovs; /* Select oversampling. We would like to oversample at the standard value * of 16, but we may not be able to achieve the baud with sufficient * accuracy if the baud is close to the HFPERCLK frequency. * * USART baud is generated according to: * * baud = fHFPERCLK/(oversample * (1 + CLKDIV/256)) * * Or, equivalently: * * CLKDIV = 256 * (fHFPERCLK / (oversample * baud) - 1) * oversample = 256 * fHFPERCLK / (baud * (CLKDIV + 256)) * * Suppose we insist on a CLKDIV >= 24, then: * * MAXoversample = 256 * fHFPERCLK / (280 * baud)) * * Example 1: fHPERCLK = 32MHz, baud=115200 * MAXoversample = 254.0, Use oversample = 16 * CLKDIV = 4188.4 * baud = 115200.0 * Example 2: fHPERCLK = 32.768KHz, baud=2400 * MAXoversample = 12.5, Use oversample = 8 * CLKDIV = 180.90 * baud = 2400.0 */ maxover = ((BOARD_HFPERCLK_FREQUENCY << 8) / 280) / baud; if (maxover >= 16) { DEBUGASSERT(baud <= (BOARD_HFPERCLK_FREQUENCY / 16)); oversample = 16; ovs = USART_CTRL_OVS_X16; } else if (maxover >= 8) { DEBUGASSERT(baud <= (BOARD_HFPERCLK_FREQUENCY / 8)); oversample = 8; ovs = USART_CTRL_OVS_X8; } else if (maxover >= 6) { DEBUGASSERT(baud <= (BOARD_HFPERCLK_FREQUENCY / 6)); oversample = 6; ovs = USART_CTRL_OVS_X6; } else /* if (maxover >= 4) */ { DEBUGASSERT(maxover >= 4 && baud <= (BOARD_HFPERCLK_FREQUENCY / 4)); oversample = 4; ovs = USART_CTRL_OVS_X4; } /* CLKDIV in asynchronous mode is given by: * * CLKDIV = 256 * (fHFPERCLK / (oversample * baud) - 1) * * or * * CLKDIV = (256 * fHFPERCLK) / (oversample * baud) - 256 */ clkdiv = ((uint64_t)BOARD_HFPERCLK_FREQUENCY << 8) / ((uint64_t)baud * oversample); if (clkdiv > 256) { clkdiv -= 256; } else { clkdiv = 0; } /* Set up the selected oversampling and baud divisor */ regval = getreg32(base + EFM32_USART_CTRL_OFFSET); regval &= ~_USART_CTRL_OVS_MASK; regval |= ovs; putreg32(regval, base + EFM32_USART_CTRL_OFFSET); regval = (uint32_t)clkdiv << _USART_CLKDIV_DIV_SHIFT; DEBUGASSERT((regval & _USART_CLKDIV_MASK) == clkdiv); putreg32(regval, base + EFM32_USART_CLKDIV_OFFSET); } #endif /**************************************************************************** * Name: efm32_leuart_setbaud * * Description: * Set optimal oversampling and set the baud for this U[S]ART. * ****************************************************************************/ #ifdef HAVE_LEUART_DEVICE static void efm32_leuart_setbaud(uintptr_t base, uint32_t baud) { uint32_t clkdiv; /* Baud is configured by: * * baud = fLEUART / (1 + CLKDIV / 256) * * Or * * CLKDIV = 256 * (fLEUART / baud - 1) * CLKDIV = (256 * fLEUART) / baud - 256 */ clkdiv = (BOARD_LFBCLK_FREQUENCY << 8) / baud; if (clkdiv > 256) { clkdiv -= 256; } else { clkdiv = 0; } DEBUGASSERT(clkdiv <= _LEUART_CLKDIV_MASK); /* Set up the selected baud */ putreg32((uint32_t)clkdiv & _LEUART_CLKDIV_DIV_MASK, base + EFM32_LEUART_CLKDIV_OFFSET); } #endif /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: efm32_lowsetup * * Description: * Called at the very beginning of _start. Performs low level * initialization including setup of the console UART. This UART done * early so that the serial console is available for debugging very early * in the boot sequence. * ****************************************************************************/ void efm32_lowsetup(void) { #if defined(HAVE_UART_DEVICE) || defined(HAVE_LEUART_DEVICE) uint32_t regval; #endif #if defined(HAVE_UART_DEVICE) || defined(HAVE_SPI_DEVICE) /* Enable clocking to configured UART/USART interfaces */ regval = getreg32(EFM32_CMU_HFPERCLKEN0); regval &= ~(CMU_HFPERCLKEN0_USART0 | CMU_HFPERCLKEN0_USART1 #ifdef CONFIG_EFM32_HAVE_USART2 | CMU_HFPERCLKEN0_USART2 #endif #ifdef CONFIG_EFM32_HAVE_UART0 | CMU_HFPERCLKEN0_UART0 #endif #ifdef CONFIG_EFM32_HAVE_UART1 | CMU_HFPERCLKEN0_UART1 #endif ); #ifdef CONFIG_EFM32_USART0 regval |= CMU_HFPERCLKEN0_USART0; #endif #ifdef CONFIG_EFM32_USART1 regval |= CMU_HFPERCLKEN0_USART1; #endif #ifdef CONFIG_EFM32_USART2 regval |= CMU_HFPERCLKEN0_USART2; #endif #ifdef CONFIG_EFM32_UART0 regval |= CMU_HFPERCLKEN0_UART0; #endif #ifdef CONFIG_EFM32_UART1 regval |= CMU_HFPERCLKEN0_UART1; #endif putreg32(regval, EFM32_CMU_HFPERCLKEN0); #endif /* HAVE_UART_DEVICE */ #ifdef HAVE_LEUART_DEVICE /* Enable clocking to configured LEUART interfaces */ regval = getreg32(EFM32_CMU_LFBCLKEN0); regval &= ~(CMU_LFBCLKEN0_LEUART0 #ifdef CONFIG_EFM32_LEUART1 | CMU_LFBCLKEN0_LEUART1 #endif ); #ifdef CONFIG_EFM32_LEUART0 regval |= CMU_LFBCLKEN0_LEUART0; #endif #ifdef CONFIG_EFM32_LEUART1 regval |= CMU_LFBCLKEN0_LEUART1; #endif putreg32(regval, EFM32_CMU_LFBCLKEN0); #endif /* HAVE_LEUART_DEVICE */ /* Set location in the ROUTE register */ #ifdef HAVE_UART_DEVICE #ifdef CONFIG_EFM32_USART0 regval = (USART_ROUTE_RXPEN | USART_ROUTE_TXPEN | (BOARD_USART0_ROUTE_LOCATION << _USART_ROUTE_LOCATION_SHIFT)); #ifdef CONFIG_EFM32_USART0_ISSPI regval |= USART_ROUTE_CLKPEN; #endif putreg32(regval, EFM32_USART0_ROUTE); #endif #ifdef CONFIG_EFM32_USART1 regval = (USART_ROUTE_RXPEN | USART_ROUTE_TXPEN | (BOARD_USART1_ROUTE_LOCATION << _USART_ROUTE_LOCATION_SHIFT)); #ifdef CONFIG_EFM32_USART1_ISSPI regval |= USART_ROUTE_CLKPEN; #endif putreg32(regval, EFM32_USART1_ROUTE); #endif #ifdef CONFIG_EFM32_USART2 regval = (USART_ROUTE_RXPEN | USART_ROUTE_TXPEN | (BOARD_USART2_ROUTE_LOCATION << _USART_ROUTE_LOCATION_SHIFT)); #ifdef CONFIG_EFM32_USART2_ISSPI regval |= USART_ROUTE_CLKPEN; #endif putreg32(regval, EFM32_USART2_ROUTE); #endif #ifdef CONFIG_EFM32_UART0 regval = (USART_ROUTE_RXPEN | USART_ROUTE_TXPEN | (BOARD_UART0_ROUTE_LOCATION << _USART_ROUTE_LOCATION_SHIFT)); putreg32(regval, EFM32_UART0_ROUTE); #endif #ifdef CONFIG_EFM32_UART1 regval = (USART_ROUTE_RXPEN | USART_ROUTE_TXPEN | (BOARD_UART1_ROUTE_LOCATION << _USART_ROUTE_LOCATION_SHIFT)); putreg32(regval, EFM32_UART1_ROUTE); #endif #endif /* HAVE_UART_DEVICE */ #ifdef HAVE_LEUART_DEVICE #ifdef CONFIG_EFM32_UART0 regval = (LEUART_ROUTE_RXPEN | LEUART_ROUTE_TXPEN | (BOARD_LEUART0_ROUTE_LOCATION << _LEUART_ROUTE_LOCATION_SHIFT)); putreg32(regval, EFM32_LEUART0_ROUTE); #endif #ifdef CONFIG_EFM32_UART1 regval = (LEUART_ROUTE_RXPEN | LEUART_ROUTE_TXPEN | (BOARD_LEUART1_ROUTE_LOCATION << _LEUART_ROUTE_LOCATION_SHIFT)); putreg32(regval, EFM32_LEUART1_ROUTE); #endif #endif /* HAVE_LEUART_DEVICE */ #if defined(HAVE_UART_CONSOLE) /* Configure the U[S]ART serial console */ efm32_uartconfigure(CONSOLE_BASE, CONSOLE_BAUD, CONSOLE_PARITY, CONSOLE_NBITS, CONSOLE_2STOP); #elif defined(HAVE_LEUART_CONSOLE) /* Configure the LEUART serial console */ efm32_leuartconfigure(CONSOLE_BASE, CONSOLE_BAUD, CONSOLE_PARITY, CONSOLE_NBITS, CONSOLE_2STOP); #endif } /***************************************************************************** * Name: efm32_lowputc * * Description: * Output one character to the UART using a simple polling method. * *****************************************************************************/ #if defined(HAVE_UART_CONSOLE) void efm32_lowputc(uint32_t ch) { /* The TX Buffer Level (TXBL) status bit indicates the level of the * transmit buffer. If TXBIL is set, TXBL is set whenever the transmit * buffer is half-full or empty. */ while ((getreg32(CONSOLE_BASE + EFM32_USART_STATUS_OFFSET) & USART_STATUS_TXBL) == 0); /* Then send the character */ putreg32((uint32_t)ch, CONSOLE_BASE + EFM32_USART_TXDATA_OFFSET); } #elif defined(HAVE_LEUART_CONSOLE) void efm32_lowputc(uint32_t ch) { /* The TX Buffer Level (TXBL) status bit indicates the level of the * transmit buffer. If TXBIL is set, TXBL is set whenever the transmit * buffer is half-full or empty. */ while ((getreg32(CONSOLE_BASE + EFM32_LEUART_STATUS_OFFSET) & LEUART_STATUS_TXBL) == 0); /* Then send the character */ putreg32((uint32_t)ch, CONSOLE_BASE + EFM32_LEUART_TXDATA_OFFSET); } #endif /***************************************************************************** * Name: efm32_uartconfigure * * Description: * Configure a U[S]ART as a RS-232 UART. * *****************************************************************************/ #ifdef HAVE_UART_DEVICE void efm32_uartconfigure(uintptr_t base, uint32_t baud, unsigned int parity, unsigned int nbits, bool stop2) { uint32_t regval = 0; /* Make sure that the U[S]ART registers are in the reset state (except for * ROUTE information which must be preserved). */ efm32_uart_reset(base); /* Configure number of data bits */ switch (nbits) { case 4: regval |= USART_FRAME_DATABITS_FOUR; break; case 5: regval |= USART_FRAME_DATABITS_FIVE; break; case 6: regval |= USART_FRAME_DATABITS_SIX; break; case 7: regval |= USART_FRAME_DATABITS_SEVEN; break; default: case 8: regval |= USART_FRAME_DATABITS_EIGHT; break; case 9: regval |= USART_FRAME_DATABITS_NINE; break; case 10: regval |= USART_FRAME_DATABITS_TEN; break; case 11: regval |= USART_FRAME_DATABITS_ELEVEN; break; case 12: regval |= USART_FRAME_DATABITS_TWELVE; break; case 13: regval |= USART_FRAME_DATABITS_THIRTEEN; break; case 14: regval |= USART_FRAME_DATABITS_FOURTEEN; break; case 15: regval |= USART_FRAME_DATABITS_FIFTEEN; break; case 16: regval |= USART_FRAME_DATABITS_SIXTEEN; break; } /* Configure parity */ switch (parity) { default: case 0: regval |= USART_FRAME_PARITY_NONE; break; case 1: regval |= USART_FRAME_PARITY_ODD; break; case 2: regval |= USART_FRAME_PARITY_EVEN; break; } /* Configure stop bits */ if (stop2) { regval |= USART_FRAME_STOPBITS_TWO; } else { regval |= USART_FRAME_STOPBITS_ONE; } putreg32(regval, base + EFM32_USART_FRAME_OFFSET); /* Set the baud clock divisor */ efm32_uart_setbaud(base, baud); /* Enable the U[S]ART */ putreg32(USART_CMD_RXEN | USART_CMD_TXEN, base + EFM32_USART_CMD_OFFSET); } #endif /***************************************************************************** * Name: efm32_leuartconfigure * * Description: * Configure a LEUART as a RS-232 UART. * *****************************************************************************/ #ifdef HAVE_LEUART_DEVICE void efm32_leuartconfigure(uintptr_t base, uint32_t baud, unsigned int parity, unsigned int nbits, bool stop2) { uint32_t regval = 0; /* Make sure that the LEUART registers are in the reset state (except for * ROUTE information which must be preserved). */ efm32_leuart_reset(base); /* Configure number of data bits */ switch (nbits) { default: case 8: regval |= LEUART_CTRL_DATABITS_EIGHT; break; case 9: regval |= LEUART_CTRL_DATABITS_NINE; break; } /* Configure parity */ switch (parity) { default: case 0: regval |= LEUART_CTRL_PARITY_NONE; break; case 1: regval |= LEUART_CTRL_PARITY_ODD; break; case 2: regval |= LEUART_CTRL_PARITY_EVEN; break; } /* Configure stop bits */ if (stop2) { regval |= _LEUART_CTRL_STOPBITS_TWO; } else { regval |= _LEUART_CTRL_STOPBITS_ONE; } putreg32(regval, base + EFM32_LEUART_CTRL_OFFSET); /* Set the baud clock divisor */ efm32_leuart_setbaud(base, baud); /* Enable the LEUART */ putreg32(LEUART_CMD_RXEN | LEUART_CMD_TXEN, base + EFM32_LEUART_CMD_OFFSET); } #endif /***************************************************************************** * Name: efm32_uart_reset * * Description: * Reset the USART/UART by disabling it and restoring all of the registers * to the initial, reset value. Only the ROUTE data set by efm32_lowsetup * is preserved. * *****************************************************************************/ #if defined(HAVE_UART_DEVICE) || defined(HAVE_SPI_DEVICE) void efm32_uart_reset(uintptr_t base) { putreg32(USART_CMD_RXDIS | USART_CMD_TXDIS | USART_CMD_MASTERDIS | USART_CMD_RXBLOCKDIS | USART_CMD_TXTRIDIS | USART_CMD_CLEARTX | USART_CMD_CLEARRX, base + EFM32_USART_CMD_OFFSET); putreg32(_USART_CTRL_RESETVALUE, base + EFM32_USART_CTRL_OFFSET); putreg32(_USART_FRAME_RESETVALUE, base + EFM32_USART_FRAME_OFFSET); putreg32(_USART_TRIGCTRL_RESETVALUE, base + EFM32_USART_TRIGCTRL_OFFSET); putreg32(_USART_CLKDIV_RESETVALUE, base + EFM32_USART_CLKDIV_OFFSET); putreg32(_USART_IEN_RESETVALUE, base + EFM32_USART_IEN_OFFSET); putreg32(_USART_IFC_MASK, base + EFM32_USART_IFC_OFFSET); putreg32(_USART_IRCTRL_RESETVALUE, base + EFM32_USART_IRCTRL_OFFSET); #if defined(EFM32_USART_INPUT_OFFSET) putreg32(_USART_INPUT_RESETVALUE, base + EFM32_USART_INPUT_OFFSET); #endif #if defined(EFM32_USART_I2SCTRL_OFFSET) putreg32(_USART_I2SCTRL_RESETVALUE, base + EFM32_USART_I2SCTRL_OFFSET); #endif } #endif /***************************************************************************** * Name: efm32_leuart_reset * * Description: * Reset the USART/UART by disabling it and restoring all of the registers * to the initial, reset value. Only the ROUTE data set by efm32_lowsetup * is preserved. * *****************************************************************************/ #ifdef HAVE_LEUART_DEVICE void efm32_leuart_reset(uintptr_t base) { putreg32(LEUART_CMD_RXDIS | LEUART_CMD_TXDIS | LEUART_CMD_RXBLOCKDIS | LEUART_CMD_CLEARTX | LEUART_CMD_CLEARRX, base + EFM32_LEUART_CMD_OFFSET); putreg32(_LEUART_CTRL_RESETVALUE, base + EFM32_LEUART_CTRL_OFFSET); putreg32(_LEUART_CLKDIV_RESETVALUE, base + EFM32_LEUART_CLKDIV_OFFSET); putreg32(_LEUART_STARTFRAME_RESETVALUE, base + EFM32_LEUART_STARTFRAME_OFFSET); putreg32(_LEUART_SIGFRAME_RESETVALUE, base + EFM32_LEUART_SIGFRAME_OFFSET); putreg32(_LEUART_IEN_RESETVALUE, base + EFM32_LEUART_IEN_OFFSET); putreg32(_LEUART_IFC_MASK, base + EFM32_LEUART_IFC_OFFSET); putreg32(_LEUART_PULSECTRL_RESETVALUE, base + EFM32_LEUART_PULSECTRL_OFFSET); #if defined(EFM32_LEUART_INPUT_OFFSET) putreg32(_LEUART_INPUT_RESETVALUE, base + EFM32_LEUART_INPUT_OFFSET); #endif } #endif