/* * Copyright (c) 2017 Piotr Mienkowski * SPDX-License-Identifier: Apache-2.0 */ /** @file * @brief UART driver for Atmel SAM MCU family. * * Note: * - Error handling is not implemented. * - The driver works only in polling mode, interrupt mode is not implemented. */ #include #include #include #include #include #include /* * Verify Kconfig configuration */ #if CONFIG_UART_SAM_PORT_0 == 1 #if CONFIG_UART_SAM_PORT_0_BAUD_RATE == 0 #error "CONFIG_UART_SAM_PORT_0_BAUD_RATE has to be bigger than 0" #endif #endif #if CONFIG_UART_SAM_PORT_1 == 1 #if CONFIG_UART_SAM_PORT_1_BAUD_RATE == 0 #error "CONFIG_UART_SAM_PORT_1_BAUD_RATE has to be bigger than 0" #endif #endif #if CONFIG_UART_SAM_PORT_2 == 1 #if CONFIG_UART_SAM_PORT_2_BAUD_RATE == 0 #error "CONFIG_UART_SAM_PORT_2_BAUD_RATE has to be bigger than 0" #endif #endif #if CONFIG_UART_SAM_PORT_3 == 1 #if CONFIG_UART_SAM_PORT_3_BAUD_RATE == 0 #error "CONFIG_UART_SAM_PORT_3_BAUD_RATE has to be bigger than 0" #endif #endif #if CONFIG_UART_SAM_PORT_4 == 1 #if CONFIG_UART_SAM_PORT_4_BAUD_RATE == 0 #error "CONFIG_UART_SAM_PORT_4_BAUD_RATE has to be bigger than 0" #endif #endif /* Device constant configuration parameters */ struct uart_sam_dev_cfg { Uart *regs; u32_t periph_id; struct soc_gpio_pin pin_rx; struct soc_gpio_pin pin_tx; }; /* Device run time data */ struct uart_sam_dev_data { u32_t baud_rate; }; #define DEV_CFG(dev) \ ((const struct uart_sam_dev_cfg *const)(dev)->config->config_info) #define DEV_DATA(dev) \ ((struct uart_sam_dev_data *const)(dev)->driver_data) static int baudrate_set(Uart *const uart, u32_t baudrate, u32_t mck_freq_hz); static int uart_sam_init(struct device *dev) { int retval; const struct uart_sam_dev_cfg *const cfg = DEV_CFG(dev); struct uart_sam_dev_data *const dev_data = DEV_DATA(dev); Uart *const uart = cfg->regs; /* Enable UART clock in PMC */ soc_pmc_peripheral_enable(cfg->periph_id); /* Connect pins to the peripheral */ soc_gpio_configure(&cfg->pin_rx); soc_gpio_configure(&cfg->pin_tx); /* Reset and disable UART */ uart->UART_CR = UART_CR_RSTRX | UART_CR_RSTTX | UART_CR_RXDIS | UART_CR_TXDIS | UART_CR_RSTSTA; /* Disable Interrupts */ uart->UART_IDR = 0xFFFFFFFF; /* 8 bits of data, no parity, 1 stop bit in normal mode, baud rate * driven by the peripheral clock, UART does not filter the receive line */ uart->UART_MR = UART_MR_PAR_NO | UART_MR_CHMODE_NORMAL; /* Set baud rate */ retval = baudrate_set(uart, dev_data->baud_rate, SOC_ATMEL_SAM_MCK_FREQ_HZ); if (retval != 0) { return retval; }; /* Enable receiver and transmitter */ uart->UART_CR = UART_CR_RXEN | UART_CR_TXEN; return 0; } static int uart_sam_poll_in(struct device *dev, unsigned char *c) { Uart *const uart = DEV_CFG(dev)->regs; if (!(uart->UART_SR & UART_SR_RXRDY)) { return -EBUSY; } /* got a character */ *c = (unsigned char)uart->UART_RHR; return 0; } static unsigned char uart_sam_poll_out(struct device *dev, unsigned char c) { Uart *const uart = DEV_CFG(dev)->regs; /* Wait for transmitter to be ready */ while (!(uart->UART_SR & UART_SR_TXRDY)) ; /* send a character */ uart->UART_THR = (u32_t)c; return c; } static int baudrate_set(Uart *const uart, u32_t baudrate, u32_t mck_freq_hz) { u32_t divisor; __ASSERT(baudrate, "baud rate has to be bigger than 0"); __ASSERT(mck_freq_hz/16 >= baudrate, "MCK frequency is too small to set required baud rate"); divisor = mck_freq_hz / 16 / baudrate; if (divisor > 0xFFFF) { return -EINVAL; }; uart->UART_BRGR = UART_BRGR_CD(divisor); return 0; } static const struct uart_driver_api uart_sam_driver_api = { .poll_in = uart_sam_poll_in, .poll_out = uart_sam_poll_out, }; /* UART0 */ #ifdef CONFIG_UART_SAM_PORT_0 static const struct uart_sam_dev_cfg uart0_sam_config = { .regs = UART0, .periph_id = ID_UART0, .pin_rx = PIN_UART0_RXD, .pin_tx = PIN_UART0_TXD, }; static struct uart_sam_dev_data uart0_sam_data = { .baud_rate = CONFIG_UART_SAM_PORT_0_BAUD_RATE, }; DEVICE_AND_API_INIT(uart0_sam, CONFIG_UART_SAM_PORT_0_NAME, &uart_sam_init, &uart0_sam_data, &uart0_sam_config, PRE_KERNEL_1, CONFIG_KERNEL_INIT_PRIORITY_DEVICE, &uart_sam_driver_api); #endif /* UART1 */ #ifdef CONFIG_UART_SAM_PORT_1 static const struct uart_sam_dev_cfg uart1_sam_config = { .regs = UART1, .periph_id = ID_UART1, .pin_rx = PIN_UART1_RXD, .pin_tx = PIN_UART1_TXD, }; static struct uart_sam_dev_data uart1_sam_data = { .baud_rate = CONFIG_UART_SAM_PORT_1_BAUD_RATE, }; DEVICE_AND_API_INIT(uart1_sam, CONFIG_UART_SAM_PORT_1_NAME, &uart_sam_init, &uart1_sam_data, &uart1_sam_config, PRE_KERNEL_1, CONFIG_KERNEL_INIT_PRIORITY_DEVICE, &uart_sam_driver_api); #endif /* UART2 */ #ifdef CONFIG_UART_SAM_PORT_2 static const struct uart_sam_dev_cfg uart2_sam_config = { .regs = UART2, .periph_id = ID_UART2, .pin_rx = PIN_UART2_RXD, .pin_tx = PIN_UART2_TXD, }; static struct uart_sam_dev_data uart2_sam_data = { .baud_rate = CONFIG_UART_SAM_PORT_2_BAUD_RATE, }; DEVICE_AND_API_INIT(uart2_sam, CONFIG_UART_SAM_PORT_2_NAME, &uart_sam_init, &uart2_sam_data, &uart2_sam_config, PRE_KERNEL_1, CONFIG_KERNEL_INIT_PRIORITY_DEVICE, &uart_sam_driver_api); #endif /* UART3 */ #ifdef CONFIG_UART_SAM_PORT_3 static const struct uart_sam_dev_cfg uart3_sam_config = { .regs = UART3, .periph_id = ID_UART3, .pin_rx = PIN_UART3_RXD, .pin_tx = PIN_UART3_TXD, }; static struct uart_sam_dev_data uart3_sam_data = { .baud_rate = CONFIG_UART_SAM_PORT_3_BAUD_RATE, }; DEVICE_AND_API_INIT(uart3_sam, CONFIG_UART_SAM_PORT_3_NAME, &uart_sam_init, &uart3_sam_data, &uart3_sam_config, PRE_KERNEL_1, CONFIG_KERNEL_INIT_PRIORITY_DEVICE, &uart_sam_driver_api); #endif /* UART4 */ #ifdef CONFIG_UART_SAM_PORT_4 static const struct uart_sam_dev_cfg uart4_sam_config = { .regs = UART4, .periph_id = ID_UART4, .pin_rx = PIN_UART4_RXD, .pin_tx = PIN_UART4_TXD, }; static struct uart_sam_dev_data uart4_sam_data = { .baud_rate = CONFIG_UART_SAM_PORT_4_BAUD_RATE, }; DEVICE_AND_API_INIT(uart4_sam, CONFIG_UART_SAM_PORT_4_NAME, &uart_sam_init, &uart4_sam_data, &uart4_sam_config, PRE_KERNEL_1, CONFIG_KERNEL_INIT_PRIORITY_DEVICE, &uart_sam_driver_api); #endif