This patch adds lpuart support for Vybrid MVF600 platform.
Signed-off-by: TsiChung Liew tsicliew@gmail.com Signed-off-by: Alison Wang b18965@freescale.com --- Changes in v3: - Move the structure definition to imx-regs.h
Changes in v2: - Define C structures and access C structures to set/read registers - Change the names to reuse this driver on other platforms
drivers/serial/Makefile | 1 + drivers/serial/serial_lpuart.c | 132 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 133 insertions(+) create mode 100644 drivers/serial/serial_lpuart.c
diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile index fbc4e97..bb6559b 100644 --- a/drivers/serial/Makefile +++ b/drivers/serial/Makefile @@ -52,6 +52,7 @@ COBJS-$(CONFIG_XILINX_UARTLITE) += serial_xuartlite.o COBJS-$(CONFIG_SANDBOX_SERIAL) += sandbox.o COBJS-$(CONFIG_SCIF_CONSOLE) += serial_sh.o COBJS-$(CONFIG_ZYNQ_SERIAL) += serial_zynq.o +COBJS-$(CONFIG_FSL_LPUART) += serial_lpuart.o
ifndef CONFIG_SPL_BUILD COBJS-$(CONFIG_USB_TTY) += usbtty.o diff --git a/drivers/serial/serial_lpuart.c b/drivers/serial/serial_lpuart.c new file mode 100644 index 0000000..51d5666 --- /dev/null +++ b/drivers/serial/serial_lpuart.c @@ -0,0 +1,132 @@ +/* + * Copyright 2013 Freescale Semiconductor, Inc. + * + * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + */ + +#include <common.h> +#include <watchdog.h> +#include <asm/io.h> +#include <serial.h> +#include <linux/compiler.h> +#include <asm/arch/imx-regs.h> +#include <asm/arch/clock.h> + +#define US1_TDRE (1 << 7) +#define US1_RDRF (1 << 5) +#define UC2_TE (1 << 3) +#define UC2_RE (1 << 2) + +DECLARE_GLOBAL_DATA_PTR; + +struct lpuart_fsl *base = (struct lpuart_fsl *)LPUART_BASE; + +static void lpuart_serial_setbrg(void) +{ + u32 clk = mxc_get_clock(MXC_UART_CLK); + u16 sbr; + + if (!gd->baudrate) + gd->baudrate = CONFIG_BAUDRATE; + + sbr = (u16)(clk / (16 * gd->baudrate)); + /* place adjustment later - n/32 BRFA */ + + __raw_writeb(sbr >> 8, &base->ubdh); + __raw_writeb(sbr & 0xff, &base->ubdl); +} + +static int lpuart_serial_getc(void) +{ + u8 status; + + while (!(__raw_readb(&base->us1) & US1_RDRF)) + WATCHDOG_RESET(); + + status = __raw_readb(&base->us1); + status |= US1_RDRF; + __raw_writeb(status, &base->us1); + + return __raw_readb(&base->ud); +} + +static void lpuart_serial_putc(const char c) +{ + if (c == '\n') + serial_putc('\r'); + + while (!(__raw_readb(&base->us1) & US1_TDRE)) + WATCHDOG_RESET(); + + __raw_writeb(c, &base->ud); +} + +/* + * Test whether a character is in the RX buffer + */ +static int lpuart_serial_tstc(void) +{ + if (__raw_readb(&base->urcfifo) == 0) + return 0; + + return 1; +} + +/* + * Initialise the serial port with the given baudrate. The settings + * are always 8 data bits, no parity, 1 stop bit, no start bits. + */ +static int lpuart_serial_init(void) +{ + u8 ctrl; + + ctrl = __raw_readb(&base->uc2); + ctrl &= ~UC2_RE; + ctrl &= ~UC2_TE; + __raw_writeb(ctrl, &base->uc2); + + __raw_writeb(0, &base->umodem); + __raw_writeb(0, &base->uc1); + + /* provide data bits, parity, stop bit, etc */ + + serial_setbrg(); + + __raw_writeb(UC2_RE | UC2_TE, &base->uc2); + + return 0; +} + +static struct serial_device lpuart_serial_drv = { + .name = "lpuart_serial", + .start = lpuart_serial_init, + .stop = NULL, + .setbrg = lpuart_serial_setbrg, + .putc = lpuart_serial_putc, + .puts = default_serial_puts, + .getc = lpuart_serial_getc, + .tstc = lpuart_serial_tstc, +}; + +void lpuart_serial_initialize(void) +{ + serial_register(&lpuart_serial_drv); +} + +__weak struct serial_device *default_serial_console(void) +{ + return &lpuart_serial_drv; +}