[U-Boot] [PATCH 2/3] serial: add LPC32X0 high-speed UART devices support

[Marek Vasut <marek.vasut@gmail.com>]

> 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>
> ---
>  arch/arm/cpu/arm926ejs/lpc32xx/devices.c |    8 ++
>  arch/arm/include/asm/arch-lpc32xx/uart.h |   60 +++++++++++++++
>  drivers/serial/Makefile                  |    1 +
>  drivers/serial/lpc32xx_hsuart.c          |  119
> ++++++++++++++++++++++++++++++ 4 files changed, 188 insertions(+), 0
> deletions(-)
>  create mode 100644 drivers/serial/lpc32xx_hsuart.c
> 
> diff --git a/arch/arm/cpu/arm926ejs/lpc32xx/devices.c
> b/arch/arm/cpu/arm926ejs/lpc32xx/devices.c index 7489fb5..df86b4e 100644
> --- a/arch/arm/cpu/arm926ejs/lpc32xx/devices.c
> +++ b/arch/arm/cpu/arm926ejs/lpc32xx/devices.c
> @@ -30,6 +30,14 @@ void lpc32xx_uart_init(unsigned int uart_id)
>  {
>  	u32 val;
> 
> +	if (uart_id < 1 || uart_id > 7)
> +		return;
> +
> +	/* Disable loopback mode, if it is set by S1L bootloader */
> +	val = readl(&uart_control->loop);
> +	val &= ~UART_LOOPBACK(CONFIG_SYS_LPC32XX_UART);
> +	writel(val, &uart_control->loop);
> +
>  	if (uart_id < 3 || uart_id > 6)
>  		return;
> 
> diff --git a/arch/arm/include/asm/arch-lpc32xx/uart.h
> b/arch/arm/include/asm/arch-lpc32xx/uart.h index 3c7e561..cb4853c 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_t {
> +	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_t {
>  	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..0663772
> --- /dev/null
> +++ b/drivers/serial/lpc32xx_hsuart.c
> @@ -0,0 +1,119 @@
> +/*
> + * 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_t *hsuart = (struct hsuart_t *)HS_UART_BASE;
> +
> +static void lpc32xx_hsuart_set_baudrate(void)
> +{
> +	u32 div;
> +
> +	/* UART rate = PERIPH_CLK / ((HSU_RATE + 1) ? 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)
> +{
> +	u32 val;
> +
> +	serial_setbrg();
> +
> +	/* Disable hardware RTS and CTS flow control */
> +	val  = readl(&hsuart->ctrl);
> +	val &= ~(HSUART_CTRL_HRTS_EN | HSUART_CTRL_HCTS_EN);
> +	writel(val, &hsuart->ctrl);
> +
> +	/* Set up RX and TX FIFO */
> +	val = HSUART_CTRL_TMO_16 | HSUART_CTRL_HSU_OFFSET(20) |
> +		HSUART_CTRL_HSU_RX_TRIG_32 | HSUART_CTRL_HSU_TX_TRIG_0;
> +	writel(val, &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;
> +}

clrsetbits_le32 where appropriate ... otherwise ok