From: Stoica Cosmin-Stefan cosminstefan.stoica@freescale.com
The Linflex module is integrated on some NXP automotive SoCs part of the former Freescale portfolio, like S32V234, an SoC for Advanced Driver Assistance Systems.
Signed-off-by: Stoica Cosmin-Stefan cosminstefan.stoica@freescale.com Signed-off-by: Chircu Bogdan Bogdan.Chircu@freescale.com Signed-off-by: Depons Eric eric.depons@freescale.com Signed-off-by: Eddy Petrișor eddy.petrisor@gmail.com --- drivers/serial/Makefile | 1 + drivers/serial/serial_linflexuart.c | 147 ++++++++++++++++++++++++++++++++++++ 2 files changed, 148 insertions(+) create mode 100644 drivers/serial/serial_linflexuart.c
diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile index ee7147a..b009478 100644 --- a/drivers/serial/Makefile +++ b/drivers/serial/Makefile @@ -33,6 +33,7 @@ obj-$(CONFIG_SCIF_CONSOLE) += serial_sh.o obj-$(CONFIG_ZYNQ_SERIAL) += serial_zynq.o obj-$(CONFIG_BFIN_SERIAL) += serial_bfin.o obj-$(CONFIG_FSL_LPUART) += serial_lpuart.o +obj-$(CONFIG_FSL_LINFLEXUART) += serial_linflexuart.o obj-$(CONFIG_ARC_SERIAL) += serial_arc.o obj-$(CONFIG_UNIPHIER_SERIAL) += serial_uniphier.o obj-$(CONFIG_STM32_SERIAL) += serial_stm32.o diff --git a/drivers/serial/serial_linflexuart.c b/drivers/serial/serial_linflexuart.c new file mode 100644 index 0000000..3c619ce --- /dev/null +++ b/drivers/serial/serial_linflexuart.c @@ -0,0 +1,147 @@ +/* + * (C) Copyright 2013-2016 Freescale Semiconductor, Inc. + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#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 LINCR1_INIT (1 << 0) +#define LINCR1_MME (1 << 4) +#define LINCR1_BF (1 << 7) +#define LINSR_LINS_INITMODE (0x00001000) +#define LINSR_LINS_MASK (0x0000F000) +#define UARTCR_UART (1 << 0) +#define UARTCR_WL0 (1 << 1) +#define UARTCR_PCE (1 << 2) +#define UARTCR_PC0 (1 << 3) +#define UARTCR_TXEN (1 << 4) +#define UARTCR_RXEN (1 << 5) +#define UARTCR_PC1 (1 << 6) +#define UARTSR_DTF (1 << 1) +#define UARTSR_DRF (1 << 2) +#define UARTSR_RMB (1 << 9) + +DECLARE_GLOBAL_DATA_PTR; + +struct linflex_fsl *base = (struct linflex_fsl *)LINFLEXUART_BASE; + +static void linflex_serial_setbrg(void) +{ + u32 clk = mxc_get_clock(MXC_UART_CLK); + u32 ibr, fbr; + + if (!gd->baudrate) + gd->baudrate = CONFIG_BAUDRATE; + + ibr = (u32) (clk / (16 * gd->baudrate)); + fbr = (u32) (clk % (16 * gd->baudrate)) * 16; + + __raw_writel(ibr, &base->linibrr); + __raw_writel(fbr, &base->linfbrr); +} + +static int linflex_serial_getc(void) +{ + char c; + + /* waiting for data reception complete - TODO: add a timeout */ + while ((__raw_readb(&base->uartsr) & UARTSR_DRF) != UARTSR_DRF); + + /* waiting for data buffer to be ready - TODO: add a timeout */ + + while ((__raw_readl(&base->uartsr) & UARTSR_RMB) != UARTSR_RMB); + + c = __raw_readl(&base->bdrm); + __raw_writeb((__raw_readb(&base->uartsr) | (UARTSR_DRF | UARTSR_RMB)), + &base->uartsr); + return c; +} + +static void linflex_serial_putc(const char c) +{ + if (c == '\n') + serial_putc('\r'); + + __raw_writeb(c, &base->bdrl); + + /* waiting for data transmission completed - TODO: add a timeout */ + while ((__raw_readb(&base->uartsr) & UARTSR_DTF) != UARTSR_DTF); + + __raw_writeb((__raw_readb(&base->uartsr) | UARTSR_DTF), &base->uartsr); +} + +/* + * Test whether a character is in the RX buffer + */ +static int linflex_serial_tstc(void) +{ + return 0; +} + +/* + * 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 linflex_serial_init(void) +{ + volatile u32 ctrl; + + /* set the Linflex in master mode amd activate by-pass filter */ + ctrl = LINCR1_BF | LINCR1_MME; + __raw_writel(ctrl, &base->lincr1); + + /* init mode */ + ctrl |= LINCR1_INIT; + __raw_writel(ctrl, &base->lincr1); + + /* waiting for init mode entry - TODO: add a timeout */ + while ((__raw_readl(&base->linsr) & LINSR_LINS_MASK) != + LINSR_LINS_INITMODE); + + /* set UART bit to allow writing other bits */ + __raw_writel(UARTCR_UART, &base->uartcr); + + /* provide data bits, parity, stop bit, etc */ + serial_setbrg(); + + /* 8 bit data, no parity, Tx and Rx enabled, UART mode */ + __raw_writel(UARTCR_PC1 | UARTCR_RXEN | UARTCR_TXEN | UARTCR_PC0 + | UARTCR_WL0 | UARTCR_UART, &base->uartcr); + + ctrl = __raw_readl(&base->lincr1); + ctrl &= ~LINCR1_INIT; + __raw_writel(ctrl, &base->lincr1); /* end init mode */ + + return 0; +} + +static struct serial_device linflex_serial_drv = { + .name = "linflex_serial", + .start = linflex_serial_init, + .stop = NULL, + .setbrg = linflex_serial_setbrg, + .putc = linflex_serial_putc, + .puts = default_serial_puts, + .getc = linflex_serial_getc, + .tstc = linflex_serial_tstc, +}; + +void linflex_serial_initialize(void) +{ + serial_register(&linflex_serial_drv); +} + +__weak struct serial_device *default_serial_console(void) +{ + return &linflex_serial_drv; +}