AArch32: Add console driver

This patch adds console drivers including the pl011 driver
for the AArch32 mode.

Change-Id: Ifd22520d370fca3e73dbbf6f2d97d6aee65b67dd

drivers/arm/pl011/aarch32/pl011_console.S

+/*
+ * Copyright (c) 2016, 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.
+ */
+#include <arch.h>
+#include <asm_macros.S>
+#include <pl011.h>
+
+/*
+ * Pull in generic functions to provide backwards compatibility for
+ * platform makefiles
+ */
+#include "../../../console/aarch32/console.S"
+
+	.globl	console_core_init
+	.globl	console_core_putc
+	.globl	console_core_getc
+
+
+	/* -----------------------------------------------
+	 * int console_core_init(uintptr_t base_addr,
+	 * unsigned int uart_clk, unsigned int baud_rate)
+	 * Function to initialize the console without a
+	 * C Runtime to print debug information. This
+	 * function will be accessed by console_init and
+	 * crash reporting.
+	 * In: r0 - console base address
+	 *     r1 - Uart clock in Hz
+	 *     r2 - Baud rate
+	 * Out: return 1 on success else 0 on error
+	 * Clobber list : r1, r2, r3
+	 * -----------------------------------------------
+	 */
+func console_core_init
+	/* Check the input base address */
+	cmp	r0, #0
+	beq	core_init_fail
+#if !PL011_GENERIC_UART
+	/* Check baud rate and uart clock for sanity */
+	cmp	r1, #0
+	beq	core_init_fail
+	cmp	r2, #0
+	beq	core_init_fail
+	/* Disable the UART before initialization */
+	ldr	r3, [r0, #UARTCR]
+	bic	r3, r3, #PL011_UARTCR_UARTEN
+	str	r3, [r0, #UARTCR]
+	/* Program the baudrate */
+	/* Divisor =  (Uart clock * 4) / baudrate */
+	lsl	r1, r1, #2
+	udiv	r2, r1, r2
+	/* IBRD = Divisor >> 6 */
+	lsr	r1, r2, #6
+	/* Write the IBRD */
+	str	r1, [r0, #UARTIBRD]
+	/* FBRD = Divisor & 0x3F */
+	and	r1, r2, #0x3f
+	/* Write the FBRD */
+	str	r1, [r0, #UARTFBRD]
+	mov	r1, #PL011_LINE_CONTROL
+	str	r1, [r0, #UARTLCR_H]
+	/* Clear any pending errors */
+	mov	r1, #0
+	str	r1, [r0, #UARTECR]
+	/* Enable tx, rx, and uart overall */
+	ldr	r1, =(PL011_UARTCR_RXE | PL011_UARTCR_TXE | PL011_UARTCR_UARTEN)
+	str	r1, [r0, #UARTCR]
+#endif
+	mov	r0, #1
+	bx	lr
+core_init_fail:
+	mov	r0, #0
+	bx	lr
+endfunc console_core_init
+
+	/* --------------------------------------------------------
+	 * int console_core_putc(int c, uintptr_t base_addr)
+	 * Function to output a character over the console. It
+	 * returns the character printed on success or -1 on error.
+	 * In : r0 - character to be printed
+	 *      r1 - console base address
+	 * Out : return -1 on error else return character.
+	 * Clobber list : r2
+	 * --------------------------------------------------------
+	 */
+func console_core_putc
+	/* Check the input parameter */
+	cmp	r1, #0
+	beq	putc_error
+	/* Prepend '\r' to '\n' */
+	cmp	r0, #0xA
+	bne	2f
+1:
+	/* Check if the transmit FIFO is full */
+	ldr	r2, [r1, #UARTFR]
+	tst	r2, #PL011_UARTFR_TXFF_BIT
+	beq	1b
+	mov	r2, #0xD
+	str	r2, [r1, #UARTDR]
+2:
+	/* Check if the transmit FIFO is full */
+	ldr	r2, [r1, #UARTFR]
+	tst	r2, #PL011_UARTFR_TXFF_BIT
+	beq	2b
+	str	r0, [r1, #UARTDR]
+	bx	lr
+putc_error:
+	mov	r0, #-1
+	bx	lr
+endfunc console_core_putc
+
+	/* ---------------------------------------------
+	 * int console_core_getc(uintptr_t base_addr)
+	 * Function to get a character from the console.
+	 * It returns the character grabbed on success
+	 * or -1 on error.
+	 * In : r0 - console base address
+	 * Clobber list : r0, r1
+	 * ---------------------------------------------
+	 */
+func console_core_getc
+	cmp	r0, #0
+	beq	getc_error
+1:
+	/* Check if the receive FIFO is empty */
+	ldr	r1, [r0, #UARTFR]
+	tst	r1, #PL011_UARTFR_RXFE_BIT
+	beq	1b
+	ldr	r1, [r0, #UARTDR]
+	mov	r0, r1
+	bx	lr
+getc_error:
+	mov	r0, #-1
+	bx	lr
+endfunc console_core_getc

drivers/console/aarch32/console.S

+/*
+ * Copyright (c) 2016, 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.
+ */
+#include <asm_macros.S>
+
+	.globl	console_init
+	.globl	console_uninit
+	.globl	console_putc
+	.globl	console_getc
+
+	/*
+	 *  The console base is in the data section and not in .bss
+	 *  even though it is zero-init. In particular, this allows
+	 *  the console functions to start using this variable before
+	 *  the runtime memory is initialized for images which do not
+	 *  need to copy the .data section from ROM to RAM.
+	 */
+.section .data.console_base ; .align 2
+	console_base: .word 0x0
+
+	/* -----------------------------------------------
+	 * int console_init(uintptr_t base_addr,
+	 * unsigned int uart_clk, unsigned int baud_rate)
+	 * Function to initialize the console without a
+	 * C Runtime to print debug information. It saves
+	 * the console base to the data section.
+	 * In: r0 - console base address
+	 *     r1 - Uart clock in Hz
+	 *     r2 - Baud rate
+	 * out: return 1 on success else 0 on error
+	 * Clobber list : r1 - r3
+	 * -----------------------------------------------
+	 */
+func console_init
+	/* Check the input base address */
+	cmp	r0, #0
+	beq	init_fail
+	ldr	r3, =console_base
+	str	r0, [r3]
+	b	console_core_init
+init_fail:
+	bx	lr
+endfunc console_init
+
+	/* -----------------------------------------------
+	 * void console_uninit(void)
+	 * Function to finish the use of console driver.
+	 * It sets the console_base as NULL so that any
+	 * further invocation of `console_putc` or
+	 * `console_getc` APIs would return error.
+	 * -----------------------------------------------
+	 */
+func console_uninit
+	mov	r0, #0
+	ldr	r3, =console_base
+	str	r0, [r3]
+	bx	lr
+endfunc console_uninit
+
+	/* ---------------------------------------------
+	 * int console_putc(int c)
+	 * Function to output a character over the
+	 * console. It returns the character printed on
+	 * success or -1 on error.
+	 * In : r0 - character to be printed
+	 * Out : return -1 on error else return character.
+	 * Clobber list : r1, r2
+	 * ---------------------------------------------
+	 */
+func console_putc
+	ldr	r2, =console_base
+	ldr	r1, [r2]
+	b	console_core_putc
+endfunc console_putc
+
+	/* ---------------------------------------------
+	 * int console_getc(void)
+	 * Function to get a character from the console.
+	 * It returns the character grabbed on success
+	 * or -1 on error.
+	 * Clobber list : r0, r1
+	 * ---------------------------------------------
+	 */
+func console_getc
+	ldr	r1, =console_base
+	ldr	r0, [r1]
+	b	console_core_getc
+endfunc console_getc

drivers/console/aarch32/skeleton_console.S

+/*
+ * Copyright (c) 2016, 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.
+ */
+#include <asm_macros.S>
+
+	/*
+	 * This file contains a skeleton console implementation that can
+	 * be used as basis for a real console implementation by platforms
+	 * that do not contain PL011 hardware.
+	 */
+
+	.globl	console_core_init
+	.globl	console_core_putc
+	.globl	console_core_getc
+
+	/* -----------------------------------------------
+	 * int console_core_init(uintptr_t base_addr,
+	 * unsigned int uart_clk, unsigned int baud_rate)
+	 * Function to initialize the console without a
+	 * C Runtime to print debug information. This
+	 * function will be accessed by console_init and
+	 * crash reporting.
+	 * In: r0 - console base address
+	 *     r1 - Uart clock in Hz
+	 *     r2 - Baud rate
+	 * Out: return 1 on success else 0 on error
+	 * Clobber list : r1, r2
+	 * -----------------------------------------------
+	 */
+func console_core_init
+	/* Check the input base address */
+	cmp	r0, #0
+	beq	core_init_fail
+	/* Check baud rate and uart clock for sanity */
+	cmp	r1, #0
+	beq	core_init_fail
+	cmp	r2, #0
+	beq	core_init_fail
+	/* Insert implementation here */
+	mov	r0, #1
+	bx	lr
+core_init_fail:
+	mov	r0, #0
+	bx	lr
+endfunc console_core_init
+
+	/* --------------------------------------------------------
+	 * int console_core_putc(int c, uintptr_t base_addr)
+	 * Function to output a character over the console. It
+	 * returns the character printed on success or -1 on error.
+	 * In : r0 - character to be printed
+	 *      r1 - console base address
+	 * Out : return -1 on error else return character.
+	 * Clobber list : r2
+	 * --------------------------------------------------------
+	 */
+func console_core_putc
+	/* Check the input parameter */
+	cmp	r1, #0
+	beq	putc_error
+	/* Insert implementation here */
+	bx	lr
+putc_error:
+	mov	r0, #-1
+	bx	lr
+endfunc console_core_putc
+
+	/* ---------------------------------------------
+	 * int console_core_getc(uintptr_t base_addr)
+	 * Function to get a character from the console.
+	 * It returns the character grabbed on success
+	 * or -1 on error.
+	 * In : r0 - console base address
+	 * Clobber list : r0, r1
+	 * ---------------------------------------------
+	 */
+func console_core_getc
+	cmp	r0, #0
+	beq	getc_error
+	/* Insert implementation here */
+	bx	lr
+getc_error:
+	mov	r0, #-1
+	bx	lr
+endfunc console_core_getc