This change adds an implementation of high-speed UART found on NXP LPC32X0 SoCs. Such UARTs are enumerated as UART1, UART2 and UART7.
Signed-off-by: Vladimir Zapolskiy vz@mleia.com Cc: Albert ARIBAUD albert.u.boot@aribaud.net Acked-by: Marek Vasut marek.vasut@gmail.com --- Changes from v2 to v3: * renamed struct hsuart_t to hsuart_regs
Changes from v1 to v2: * simplified lpc32xx_hsuart_init() a little * put SoC specific changes into patch 1/3
arch/arm/include/asm/arch-lpc32xx/uart.h | 60 ++++++++++++++++ drivers/serial/Makefile | 1 + drivers/serial/lpc32xx_hsuart.c | 112 ++++++++++++++++++++++++++++++ 3 files changed, 173 insertions(+), 0 deletions(-) create mode 100644 drivers/serial/lpc32xx_hsuart.c
diff --git a/arch/arm/include/asm/arch-lpc32xx/uart.h b/arch/arm/include/asm/arch-lpc32xx/uart.h index b613df8..ec12893 100644 --- a/arch/arm/include/asm/arch-lpc32xx/uart.h +++ b/arch/arm/include/asm/arch-lpc32xx/uart.h @@ -22,6 +22,66 @@
#include <asm/types.h>
+/* 14-clock UART Registers */ +struct hsuart_regs { + union { + u32 rx; /* Receiver FIFO */ + u32 tx; /* Transmitter FIFO */ + }; + u32 level; /* FIFO Level Register */ + u32 iir; /* Interrupt ID Register */ + u32 ctrl; /* Control Register */ + u32 rate; /* Rate Control Register */ +}; + +/* 14-clock UART Receiver FIFO Register bits */ +#define HSUART_RX_BREAK (1 << 10) +#define HSUART_RX_ERROR (1 << 9) +#define HSUART_RX_EMPTY (1 << 8) +#define HSUART_RX_DATA (0xff << 0) + +/* 14-clock UART Level Register bits */ +#define HSUART_LEVEL_TX (0xff << 8) +#define HSUART_LEVEL_RX (0xff << 0) + +/* 14-clock UART Interrupt Identification Register bits */ +#define HSUART_IIR_TX_INT_SET (1 << 6) +#define HSUART_IIR_RX_OE (1 << 5) +#define HSUART_IIR_BRK (1 << 4) +#define HSUART_IIR_FE (1 << 3) +#define HSUART_IIR_RX_TIMEOUT (1 << 2) +#define HSUART_IIR_RX_TRIG (1 << 1) +#define HSUART_IIR_TX (1 << 0) + +/* 14-clock UART Control Register bits */ +#define HSUART_CTRL_HRTS_INV (1 << 21) +#define HSUART_CTRL_HRTS_TRIG_48 (0x3 << 19) +#define HSUART_CTRL_HRTS_TRIG_32 (0x2 << 19) +#define HSUART_CTRL_HRTS_TRIG_16 (0x1 << 19) +#define HSUART_CTRL_HRTS_TRIG_8 (0x0 << 19) +#define HSUART_CTRL_HRTS_EN (1 << 18) +#define HSUART_CTRL_TMO_16 (0x3 << 16) +#define HSUART_CTRL_TMO_8 (0x2 << 16) +#define HSUART_CTRL_TMO_4 (0x1 << 16) +#define HSUART_CTRL_TMO_DISABLED (0x0 << 16) +#define HSUART_CTRL_HCTS_INV (1 << 15) +#define HSUART_CTRL_HCTS_EN (1 << 14) +#define HSUART_CTRL_HSU_OFFSET(n) ((n) << 9) +#define HSUART_CTRL_HSU_BREAK (1 << 8) +#define HSUART_CTRL_HSU_ERR_INT_EN (1 << 7) +#define HSUART_CTRL_HSU_RX_INT_EN (1 << 6) +#define HSUART_CTRL_HSU_TX_INT_EN (1 << 5) +#define HSUART_CTRL_HSU_RX_TRIG_48 (0x5 << 2) +#define HSUART_CTRL_HSU_RX_TRIG_32 (0x4 << 2) +#define HSUART_CTRL_HSU_RX_TRIG_16 (0x3 << 2) +#define HSUART_CTRL_HSU_RX_TRIG_8 (0x2 << 2) +#define HSUART_CTRL_HSU_RX_TRIG_4 (0x1 << 2) +#define HSUART_CTRL_HSU_RX_TRIG_1 (0x0 << 2) +#define HSUART_CTRL_HSU_TX_TRIG_16 (0x3 << 0) +#define HSUART_CTRL_HSU_TX_TRIG_8 (0x2 << 0) +#define HSUART_CTRL_HSU_TX_TRIG_4 (0x1 << 0) +#define HSUART_CTRL_HSU_TX_TRIG_0 (0x0 << 0) + /* UART Control Registers */ struct uart_ctrl_regs { u32 ctrl; /* Control Register */ diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile index 616b857..65d0f23 100644 --- a/drivers/serial/Makefile +++ b/drivers/serial/Makefile @@ -29,6 +29,7 @@ COBJS-$(CONFIG_ALTERA_UART) += altera_uart.o COBJS-$(CONFIG_ALTERA_JTAG_UART) += altera_jtag_uart.o COBJS-$(CONFIG_ARM_DCC) += arm_dcc.o COBJS-$(CONFIG_ATMEL_USART) += atmel_usart.o +COBJS-$(CONFIG_LPC32XX_HSUART) += lpc32xx_hsuart.o COBJS-$(CONFIG_MCFUART) += mcfuart.o COBJS-$(CONFIG_NS9750_UART) += ns9750_serial.o COBJS-$(CONFIG_OPENCORES_YANU) += opencores_yanu.o diff --git a/drivers/serial/lpc32xx_hsuart.c b/drivers/serial/lpc32xx_hsuart.c new file mode 100644 index 0000000..8ce3382 --- /dev/null +++ b/drivers/serial/lpc32xx_hsuart.c @@ -0,0 +1,112 @@ +/* + * Copyright (C) 2011 Vladimir Zapolskiy vz@mleia.com + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, + * MA 02110-1301, USA. + */ + +#include <common.h> +#include <asm/arch/cpu.h> +#include <asm/arch/clk.h> +#include <asm/arch/uart.h> +#include <asm/io.h> + +DECLARE_GLOBAL_DATA_PTR; + +static struct hsuart_regs *hsuart = (struct hsuart_regs *)HS_UART_BASE; + +static void lpc32xx_hsuart_set_baudrate(void) +{ + u32 div; + + /* UART rate = PERIPH_CLK / ((HSU_RATE + 1) x 14) */ + div = (get_serial_clock() / 14 + gd->baudrate / 2) / gd->baudrate - 1; + if (div > 255) + div = 255; + + writel(div, &hsuart->rate); +} + +static int lpc32xx_hsuart_getc(void) +{ + while (!(readl(&hsuart->level) & HSUART_LEVEL_RX)) + /* NOP */; + + return readl(&hsuart->rx) & HSUART_RX_DATA; +} + +static void lpc32xx_hsuart_putc(const char c) +{ + writel(c, &hsuart->tx); + + /* Wait for character to be sent */ + while (readl(&hsuart->level) & HSUART_LEVEL_TX) + /* NOP */; +} + +static int lpc32xx_hsuart_tstc(void) +{ + if (readl(&hsuart->level) & HSUART_LEVEL_RX) + return 1; + + return 0; +} + +static void lpc32xx_hsuart_init(void) +{ + lpc32xx_hsuart_set_baudrate(); + + /* Disable hardware RTS and CTS flow control, set up RX and TX FIFO */ + writel(HSUART_CTRL_TMO_16 | HSUART_CTRL_HSU_OFFSET(20) | + HSUART_CTRL_HSU_RX_TRIG_32 | HSUART_CTRL_HSU_TX_TRIG_0, + &hsuart->ctrl); +} + +void serial_setbrg(void) +{ + return lpc32xx_hsuart_set_baudrate(); +} + +void serial_putc(const char c) +{ + lpc32xx_hsuart_putc(c); + + /* If \n, also do \r */ + if (c == '\n') + lpc32xx_hsuart_putc('\r'); +} + +int serial_getc(void) +{ + return lpc32xx_hsuart_getc(); +} + +void serial_puts(const char *s) +{ + while (*s) + serial_putc(*s++); +} + +int serial_tstc(void) +{ + return lpc32xx_hsuart_tstc(); +} + +int serial_init(void) +{ + lpc32xx_hsuart_init(); + + return 0; +}