linux/linux-5.4.31/arch/mips/include/asm/netlogic/xlp-hal/uart.h

193 lines
5.0 KiB
C

/*
* Copyright 2003-2011 NetLogic Microsystems, Inc. (NetLogic). All rights
* reserved.
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
* General Public License (GPL) Version 2, available from the file
* COPYING in the main directory of this source tree, or the NetLogic
* license below:
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY NETLOGIC ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL NETLOGIC OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
* IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef __XLP_HAL_UART_H__
#define __XLP_HAL_UART_H__
/* UART Specific registers */
#define UART_RX_DATA 0x00
#define UART_TX_DATA 0x00
#define UART_INT_EN 0x01
#define UART_INT_ID 0x02
#define UART_FIFO_CTL 0x02
#define UART_LINE_CTL 0x03
#define UART_MODEM_CTL 0x04
#define UART_LINE_STS 0x05
#define UART_MODEM_STS 0x06
#define UART_DIVISOR0 0x00
#define UART_DIVISOR1 0x01
#define BASE_BAUD (XLP_IO_CLK/16)
#define BAUD_DIVISOR(baud) (BASE_BAUD / baud)
/* LCR mask values */
#define LCR_5BITS 0x00
#define LCR_6BITS 0x01
#define LCR_7BITS 0x02
#define LCR_8BITS 0x03
#define LCR_STOPB 0x04
#define LCR_PENAB 0x08
#define LCR_PODD 0x00
#define LCR_PEVEN 0x10
#define LCR_PONE 0x20
#define LCR_PZERO 0x30
#define LCR_SBREAK 0x40
#define LCR_EFR_ENABLE 0xbf
#define LCR_DLAB 0x80
/* MCR mask values */
#define MCR_DTR 0x01
#define MCR_RTS 0x02
#define MCR_DRS 0x04
#define MCR_IE 0x08
#define MCR_LOOPBACK 0x10
/* FCR mask values */
#define FCR_RCV_RST 0x02
#define FCR_XMT_RST 0x04
#define FCR_RX_LOW 0x00
#define FCR_RX_MEDL 0x40
#define FCR_RX_MEDH 0x80
#define FCR_RX_HIGH 0xc0
/* IER mask values */
#define IER_ERXRDY 0x1
#define IER_ETXRDY 0x2
#define IER_ERLS 0x4
#define IER_EMSC 0x8
#if !defined(LOCORE) && !defined(__ASSEMBLY__)
#define nlm_read_uart_reg(b, r) nlm_read_reg(b, r)
#define nlm_write_uart_reg(b, r, v) nlm_write_reg(b, r, v)
#define nlm_get_uart_pcibase(node, inst) \
nlm_pcicfg_base(cpu_is_xlp9xx() ? XLP9XX_IO_UART_OFFSET(node) : \
XLP_IO_UART_OFFSET(node, inst))
#define nlm_get_uart_regbase(node, inst) \
(nlm_get_uart_pcibase(node, inst) + XLP_IO_PCI_HDRSZ)
static inline void
nlm_uart_set_baudrate(uint64_t base, int baud)
{
uint32_t lcr;
lcr = nlm_read_uart_reg(base, UART_LINE_CTL);
/* enable divisor register, and write baud values */
nlm_write_uart_reg(base, UART_LINE_CTL, lcr | (1 << 7));
nlm_write_uart_reg(base, UART_DIVISOR0,
(BAUD_DIVISOR(baud) & 0xff));
nlm_write_uart_reg(base, UART_DIVISOR1,
((BAUD_DIVISOR(baud) >> 8) & 0xff));
/* restore default lcr */
nlm_write_uart_reg(base, UART_LINE_CTL, lcr);
}
static inline void
nlm_uart_outbyte(uint64_t base, char c)
{
uint32_t lsr;
for (;;) {
lsr = nlm_read_uart_reg(base, UART_LINE_STS);
if (lsr & 0x20)
break;
}
nlm_write_uart_reg(base, UART_TX_DATA, (int)c);
}
static inline char
nlm_uart_inbyte(uint64_t base)
{
int data, lsr;
for (;;) {
lsr = nlm_read_uart_reg(base, UART_LINE_STS);
if (lsr & 0x80) { /* parity/frame/break-error - push a zero */
data = 0;
break;
}
if (lsr & 0x01) { /* Rx data */
data = nlm_read_uart_reg(base, UART_RX_DATA);
break;
}
}
return (char)data;
}
static inline int
nlm_uart_init(uint64_t base, int baud, int databits, int stopbits,
int parity, int int_en, int loopback)
{
uint32_t lcr;
lcr = 0;
if (databits >= 8)
lcr |= LCR_8BITS;
else if (databits == 7)
lcr |= LCR_7BITS;
else if (databits == 6)
lcr |= LCR_6BITS;
else
lcr |= LCR_5BITS;
if (stopbits > 1)
lcr |= LCR_STOPB;
lcr |= parity << 3;
/* setup default lcr */
nlm_write_uart_reg(base, UART_LINE_CTL, lcr);
/* Reset the FIFOs */
nlm_write_uart_reg(base, UART_LINE_CTL, FCR_RCV_RST | FCR_XMT_RST);
nlm_uart_set_baudrate(base, baud);
if (loopback)
nlm_write_uart_reg(base, UART_MODEM_CTL, 0x1f);
if (int_en)
nlm_write_uart_reg(base, UART_INT_EN, IER_ERXRDY | IER_ETXRDY);
return 0;
}
#endif /* !LOCORE && !__ASSEMBLY__ */
#endif /* __XLP_HAL_UART_H__ */