From f53473fa67b453813e43340fb654385b621c07c8 Mon Sep 17 00:00:00 2001 From: G S Niteesh Date: Mon, 10 Feb 2020 00:51:44 +0530 Subject: bsp/raspberrypi: Mini UART driver This patch adds driver for Mini UART present in Raspberry Pi 3 and above, this UART is currently used as the primary UART in these models. The Mini UART is similar to ns16550, this driver is built upon libchip/ns16550. --- bsps/arm/raspberrypi/console/console-config.c | 118 ++++++++++++++++++++++++-- bsps/arm/raspberrypi/include/bsp/usart.h | 1 + 2 files changed, 110 insertions(+), 9 deletions(-) (limited to 'bsps') diff --git a/bsps/arm/raspberrypi/console/console-config.c b/bsps/arm/raspberrypi/console/console-config.c index fffe7c432e..bb0b596019 100644 --- a/bsps/arm/raspberrypi/console/console-config.c +++ b/bsps/arm/raspberrypi/console/console-config.c @@ -24,6 +24,7 @@ #include #include +#include #include #include @@ -34,35 +35,103 @@ #include #include #include +#include +#include - -#define UART0 "/dev/ttyS0" +/** + * UART0 - PL011 + * UART1 - Mini UART + */ +#define PL011 "/dev/ttyAMA0" +#define MINIUART "/dev/ttyS0" #define FBCONS "/dev/fbcons" arm_pl011_context pl011_context; +ns16550_context mini_uart_context; rpi_fb_context fb_context; -static void output_char_serial(char c) +static void output_char_pl011(char c) { arm_pl011_write_polled(&pl011_context.base, c); } +static void output_char_mini_uart(char c) +{ + ns16550_polled_putchar(&mini_uart_context.base, c); +} + void output_char_fb(char c) { fbcons_write_polled(&fb_context.base, c); } +static uint8_t mini_uart_get_reg(uintptr_t port, uint8_t index) +{ + volatile uint32_t *val = (volatile uint32_t *)port + index; + return (uint8_t) *val; +} + +static void mini_uart_set_reg(uintptr_t port, uint8_t index, uint8_t val) +{ + volatile uint32_t *reg = (volatile uint32_t *)port + index; + *reg = val; +} + static void init_ctx_arm_pl011( const void *fdt, int node ) { arm_pl011_context *ctx = &pl011_context; - rtems_termios_device_context_initialize(&ctx->base, "UART"); + rtems_termios_device_context_initialize(&ctx->base, "PL011UART"); ctx->regs = raspberrypi_get_reg_of_node(fdt, node); } +static uint32_t calculate_baud_divisor( + ns16550_context *ctx, + uint32_t baud +) +{ + uint32_t baudDivisor = (ctx->clock / (8 * baud)) - 1; + return baudDivisor; +} + +static void init_ctx_mini_uart( + const void *fdt, + int node +) +{ + const char *status; + int len; + ns16550_context *ctx; + + memset(&mini_uart_context, 0, sizeof(mini_uart_context)); + ctx = &mini_uart_context; + + rtems_termios_device_context_initialize(&ctx->base, "MiniUART"); + + status = fdt_getprop(fdt, node, "status", &len); + if ( status == NULL || strcmp(status, "disabled" ) == 0){ + return ; + } + + ctx->port = (uintptr_t) raspberrypi_get_reg_of_node(fdt, node); + ctx->initial_baud = MINI_UART_DEFAULT_BAUD; + ctx->clock = BCM2835_CLOCK_FREQ; + ctx->calculate_baud_divisor = calculate_baud_divisor; + ctx->get_reg = mini_uart_get_reg; + ctx->set_reg = mini_uart_set_reg; + + rtems_gpio_bsp_select_specific_io(0, 14, RPI_ALT_FUNC_5, NULL); + rtems_gpio_bsp_select_specific_io(0, 15, RPI_ALT_FUNC_5, NULL); + rtems_gpio_bsp_set_resistor_mode(0, 14, NO_PULL_RESISTOR); + rtems_gpio_bsp_set_resistor_mode(0, 15, NO_PULL_RESISTOR); + + BCM2835_REG(AUX_ENABLES) |= 0x1; + ns16550_probe(&ctx->base); +} + static void register_fb( void ) { if (fbcons_probe(&fb_context.base) == true) { @@ -87,16 +156,28 @@ static void console_select( void ) link(FBCONS, CONSOLE_DEVICE_NAME); return ; } + } else if ( strncmp( opt, MINIUART, sizeof(MINIUART) - 1 ) == 0) { + BSP_output_char = output_char_mini_uart; + link(MINIUART, CONSOLE_DEVICE_NAME); + } else if ( strncmp( opt, PL011, sizeof(PL011) - 1 ) == 0) { + BSP_output_char = output_char_pl011; + link(PL011, CONSOLE_DEVICE_NAME); } + }else { + /** + * If no command line option was given, default to PL011. + */ + BSP_output_char = output_char_pl011; + link(PL011, CONSOLE_DEVICE_NAME); } - BSP_output_char = output_char_serial; - link(UART0, CONSOLE_DEVICE_NAME); } static void uart_probe(void) { static bool initialized = false; const void *fdt; + const char *console; + int len; int node; if ( initialized ) { @@ -104,17 +185,29 @@ static void uart_probe(void) } fdt = bsp_fdt_get(); - node = fdt_node_offset_by_compatible(fdt, -1, "brcm,bcm2835-pl011"); + node = fdt_node_offset_by_compatible(fdt, -1, "brcm,bcm2835-pl011"); init_ctx_arm_pl011(fdt, node); + node = fdt_node_offset_by_compatible(fdt, -1, "brcm,bcm2835-aux-uart"); + init_ctx_mini_uart(fdt, node); + + node = fdt_path_offset(fdt, "/aliases"); + console = fdt_getprop(fdt, node, "serial0", &len); + + if ( strcmp(console, "/soc/serial@7e215040" ) == 0) { + BSP_output_char = output_char_mini_uart; + }else { + BSP_output_char = output_char_pl011; + } + initialized = true; } static void output_char(char c) { uart_probe(); - output_char_serial(c); + (*BSP_output_char)(c); } rtems_status_code console_initialize( @@ -127,12 +220,19 @@ rtems_status_code console_initialize( uart_probe(); rtems_termios_device_install( - UART0, + PL011, &arm_pl011_fns, NULL, &pl011_context.base ); + rtems_termios_device_install( + MINIUART, + &ns16550_handler_polled, + NULL, + &mini_uart_context.base + ); + register_fb(); console_select(); diff --git a/bsps/arm/raspberrypi/include/bsp/usart.h b/bsps/arm/raspberrypi/include/bsp/usart.h index abbf53626c..6af1844b3c 100644 --- a/bsps/arm/raspberrypi/include/bsp/usart.h +++ b/bsps/arm/raspberrypi/include/bsp/usart.h @@ -33,6 +33,7 @@ extern "C" { #endif /* __cplusplus */ #define PL011_DEFAULT_BAUD 115000 +#define MINI_UART_DEFAULT_BAUD 115200 #define BCM2835_PL011_BASE (RPI_PERIPHERAL_BASE + 0x201000) #ifdef __cplusplus -- cgit v1.2.3