arm-trusted-firmware/include/drivers/arm/pl011.h
Juan Castillo 9400b40ea4 Disable PL011 UART before configuring it
The PL011 TRM (ARM DDI 0183G) specifies that the UART must be
disabled before any of the control registers are programmed. The
PL011 driver included in TF does not disable the UART, so the
initialization in BL2 and BL31 is violating this requirement
(and potentially in BL1 if the UART is enabled after reset).

This patch modifies the initialization function in the PL011
console driver to disable the UART before programming the
control registers.

Register clobber list and documentation updated.

Fixes ARM-software/tf-issues#300

Change-Id: I839b2d681d48b03f821ac53663a6a78e8b30a1a1
2016-01-21 17:27:47 +00:00

107 lines
4.6 KiB
C

/*
* Copyright (c) 2013-2014, ARM Limited and Contributors. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 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.
*
* Neither the name of ARM nor the names of its contributors may be used
* to endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 THE COPYRIGHT HOLDER 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 __PL011_H__
#define __PL011_H__
/* PL011 Registers */
#define UARTDR 0x000
#define UARTRSR 0x004
#define UARTECR 0x004
#define UARTFR 0x018
#define UARTIMSC 0x038
#define UARTRIS 0x03C
#define UARTICR 0x044
/* PL011 registers (out of the SBSA specification) */
#if !PL011_GENERIC_UART
#define UARTILPR 0x020
#define UARTIBRD 0x024
#define UARTFBRD 0x028
#define UARTLCR_H 0x02C
#define UARTCR 0x030
#define UARTIFLS 0x034
#define UARTMIS 0x040
#define UARTDMACR 0x048
#endif /* !PL011_GENERIC_UART */
/* Data status bits */
#define UART_DATA_ERROR_MASK 0x0F00
/* Status reg bits */
#define UART_STATUS_ERROR_MASK 0x0F
/* Flag reg bits */
#define PL011_UARTFR_RI (1 << 8) /* Ring indicator */
#define PL011_UARTFR_TXFE (1 << 7) /* Transmit FIFO empty */
#define PL011_UARTFR_RXFF (1 << 6) /* Receive FIFO full */
#define PL011_UARTFR_TXFF (1 << 5) /* Transmit FIFO full */
#define PL011_UARTFR_RXFE (1 << 4) /* Receive FIFO empty */
#define PL011_UARTFR_BUSY (1 << 3) /* UART busy */
#define PL011_UARTFR_DCD (1 << 2) /* Data carrier detect */
#define PL011_UARTFR_DSR (1 << 1) /* Data set ready */
#define PL011_UARTFR_CTS (1 << 0) /* Clear to send */
#define PL011_UARTFR_TXFF_BIT 5 /* Transmit FIFO full bit in UARTFR register */
#define PL011_UARTFR_RXFE_BIT 4 /* Receive FIFO empty bit in UARTFR register */
#define PL011_UARTFR_BUSY_BIT 3 /* UART busy bit in UARTFR register */
/* Control reg bits */
#if !PL011_GENERIC_UART
#define PL011_UARTCR_CTSEN (1 << 15) /* CTS hardware flow control enable */
#define PL011_UARTCR_RTSEN (1 << 14) /* RTS hardware flow control enable */
#define PL011_UARTCR_RTS (1 << 11) /* Request to send */
#define PL011_UARTCR_DTR (1 << 10) /* Data transmit ready. */
#define PL011_UARTCR_RXE (1 << 9) /* Receive enable */
#define PL011_UARTCR_TXE (1 << 8) /* Transmit enable */
#define PL011_UARTCR_LBE (1 << 7) /* Loopback enable */
#define PL011_UARTCR_UARTEN (1 << 0) /* UART Enable */
#if !defined(PL011_LINE_CONTROL)
/* FIFO Enabled / No Parity / 8 Data bit / One Stop Bit */
#define PL011_LINE_CONTROL (PL011_UARTLCR_H_FEN | PL011_UARTLCR_H_WLEN_8)
#endif
/* Line Control Register Bits */
#define PL011_UARTLCR_H_SPS (1 << 7) /* Stick parity select */
#define PL011_UARTLCR_H_WLEN_8 (3 << 5)
#define PL011_UARTLCR_H_WLEN_7 (2 << 5)
#define PL011_UARTLCR_H_WLEN_6 (1 << 5)
#define PL011_UARTLCR_H_WLEN_5 (0 << 5)
#define PL011_UARTLCR_H_FEN (1 << 4) /* FIFOs Enable */
#define PL011_UARTLCR_H_STP2 (1 << 3) /* Two stop bits select */
#define PL011_UARTLCR_H_EPS (1 << 2) /* Even parity select */
#define PL011_UARTLCR_H_PEN (1 << 1) /* Parity Enable */
#define PL011_UARTLCR_H_BRK (1 << 0) /* Send break */
#endif /* !PL011_GENERIC_UART */
#endif /* __PL011_H__ */