drivers: arm: pl011: Update PL011 driver to support MULTI_CONSOLE_API

This patch updates the ARM PL011 console driver to support the new
console API. The driver will continue to support the old API as well by
checking the MULTI_CONSOLE_API compile-time flag.

Change-Id: Ic34e4158addbb0c5fae500c9cff899c05a4f4206
Signed-off-by: Julius Werner <jwerner@chromium.org>
diff --git a/drivers/arm/pl011/aarch64/pl011_console.S b/drivers/arm/pl011/aarch64/pl011_console.S
index 8b15d56..6f2510a 100644
--- a/drivers/arm/pl011/aarch64/pl011_console.S
+++ b/drivers/arm/pl011/aarch64/pl011_console.S
@@ -5,6 +5,7 @@
  */
 #include <arch.h>
 #include <asm_macros.S>
+#include <assert_macros.S>
 #include <pl011.h>
 
 /*
@@ -13,15 +14,21 @@
  */
 #include "../../../console/aarch64/console.S"
 
-
-	.globl	console_core_init
-	.globl	console_core_putc
-	.globl	console_core_getc
-	.globl	console_core_flush
+	/*
+	 * "core" functions are low-level implementations that don't require
+	 * writable memory and are thus safe to call in BL1 crash context.
+	 */
+	.globl console_pl011_core_init
+	.globl console_pl011_core_putc
+	.globl console_pl011_core_getc
+	.globl console_pl011_core_flush
 
+	.globl	console_pl011_putc
+	.globl	console_pl011_getc
+	.globl	console_pl011_flush
 
 	/* -----------------------------------------------
-	 * int console_core_init(uintptr_t base_addr,
+	 * int console_pl011_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
@@ -34,7 +41,7 @@
 	 * Clobber list : x1, x2, x3, x4
 	 * -----------------------------------------------
 	 */
-func console_core_init
+func console_pl011_core_init
 	/* Check the input base address */
 	cbz	x0, core_init_fail
 #if !PL011_GENERIC_UART
@@ -71,10 +78,54 @@
 core_init_fail:
 	mov	w0, wzr
 	ret
-endfunc console_core_init
+endfunc console_pl011_core_init
+
+#if MULTI_CONSOLE_API
+	.globl console_pl011_register
+
+	/* -----------------------------------------------
+	 * int console_pl011_register(console_pl011_t *console,
+		uintptr_t base, uint32_t clk, uint32_t baud)
+	 * Function to initialize and register a new PL011
+	 * console. Storage passed in for the console struct
+	 * *must* be persistent (i.e. not from the stack).
+	 * In: x0 - UART register base address
+	 *     w1 - UART clock in Hz
+	 *     w2 - Baud rate
+	 *     x3 - pointer to empty console_pl011_t struct
+	 * Out: return 1 on success, 0 on error
+	 * Clobber list : x0, x1, x2, x6, x7, x14
+	 * -----------------------------------------------
+	 */
+func console_pl011_register
+	mov	x7, x30
+	mov	x6, x3
+	cbz	x6, register_fail
+	str	x0, [x6, #CONSOLE_T_PL011_BASE]
+
+	bl	console_pl011_core_init
+	cbz	x0, register_fail
+
+	mov	x0, x6
+	mov	x30, x7
+	finish_console_register pl011
+
+register_fail:
+	ret	x7
+endfunc console_pl011_register
+#else
+	.globl console_core_init
+	.globl console_core_putc
+	.globl console_core_getc
+	.globl console_core_flush
+	.equ console_core_init,console_pl011_core_init
+	.equ console_core_putc,console_pl011_core_putc
+	.equ console_core_getc,console_pl011_core_getc
+	.equ console_core_flush,console_pl011_core_flush
+#endif
 
 	/* --------------------------------------------------------
-	 * int console_core_putc(int c, uintptr_t base_addr)
+	 * int console_pl011_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 : w0 - character to be printed
@@ -83,9 +134,12 @@
 	 * Clobber list : x2
 	 * --------------------------------------------------------
 	 */
-func console_core_putc
-	/* Check the input parameter */
-	cbz	x1, putc_error
+func console_pl011_core_putc
+#if ENABLE_ASSERTIONS
+	cmp	x1, #0
+	ASM_ASSERT(ne)
+#endif /* ENABLE_ASSERTIONS */
+
 	/* Prepend '\r' to '\n' */
 	cmp	w0, #0xA
 	b.ne	2f
@@ -101,36 +155,75 @@
 	tbnz	w2, #PL011_UARTFR_TXFF_BIT, 2b
 	str	w0, [x1, #UARTDR]
 	ret
-putc_error:
-	mov	w0, #-1
-	ret
-endfunc console_core_putc
+endfunc console_pl011_core_putc
+
+	/* --------------------------------------------------------
+	 * int console_pl011_putc(int c, console_pl011_t *console)
+	 * Function to output a character over the console. It
+	 * returns the character printed on success or -1 on error.
+	 * In : w0 - character to be printed
+	 *      x1 - pointer to console_t structure
+	 * Out : return -1 on error else return character.
+	 * Clobber list : x2
+	 * --------------------------------------------------------
+	 */
+func console_pl011_putc
+#if ENABLE_ASSERTIONS
+	cmp	x1, #0
+	ASM_ASSERT(ne)
+#endif /* ENABLE_ASSERTIONS */
+	ldr	x1, [x1, #CONSOLE_T_PL011_BASE]
+	b	console_pl011_core_putc
+endfunc console_pl011_putc
 
 	/* ---------------------------------------------
-	 * int console_core_getc(uintptr_t base_addr)
+	 * int console_pl011_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.
+	 * or -1 if no character is available.
 	 * In : x0 - console base address
+	 * Out: w0 - character if available, else -1
 	 * Clobber list : x0, x1
 	 * ---------------------------------------------
 	 */
-func console_core_getc
-	cbz	x0, getc_error
-1:
+func console_pl011_core_getc
+#if ENABLE_ASSERTIONS
+	cmp	x0, #0
+	ASM_ASSERT(ne)
+#endif /* ENABLE_ASSERTIONS */
+
 	/* Check if the receive FIFO is empty */
 	ldr	w1, [x0, #UARTFR]
-	tbnz	w1, #PL011_UARTFR_RXFE_BIT, 1b
+	tbnz	w1, #PL011_UARTFR_RXFE_BIT, no_char
 	ldr	w1, [x0, #UARTDR]
 	mov	w0, w1
 	ret
-getc_error:
-	mov	w0, #-1
+no_char:
+	mov	w0, #ERROR_NO_PENDING_CHAR
 	ret
-endfunc console_core_getc
+endfunc console_pl011_core_getc
+
+	/* ---------------------------------------------
+	 * int console_pl011_getc(console_pl011_t *console)
+	 * Function to get a character from the console.
+	 * It returns the character grabbed on success
+	 * or -1 if no character is available.
+	 * In : x0 - pointer to console_t structure
+	 * Out: w0 - character if available, else -1
+	 * Clobber list : x0, x1
+	 * ---------------------------------------------
+	 */
+func console_pl011_getc
+#if ENABLE_ASSERTIONS
+	cmp	x0, #0
+	ASM_ASSERT(ne)
+#endif /* ENABLE_ASSERTIONS */
+	ldr	x0, [x0, #CONSOLE_T_PL011_BASE]
+	b	console_pl011_core_getc
+endfunc console_pl011_getc
 
 	/* ---------------------------------------------
-	 * int console_core_flush(uintptr_t base_addr)
+	 * int console_pl011_core_flush(uintptr_t base_addr)
 	 * Function to force a write of all buffered
 	 * data that hasn't been output.
 	 * In : x0 - console base address
@@ -138,9 +231,11 @@
 	 * Clobber list : x0, x1
 	 * ---------------------------------------------
 	 */
-func console_core_flush
-	cbz	x0, flush_error
-
+func console_pl011_core_flush
+#if ENABLE_ASSERTIONS
+	cmp	x0, #0
+	ASM_ASSERT(ne)
+#endif /* ENABLE_ASSERTIONS */
 1:
 	/* Loop until the transmit FIFO is empty */
 	ldr	w1, [x0, #UARTFR]
@@ -148,7 +243,22 @@
 
 	mov	w0, #0
 	ret
-flush_error:
-	mov	w0, #-1
-	ret
-endfunc console_core_flush
+endfunc console_pl011_core_flush
+
+	/* ---------------------------------------------
+	 * int console_pl011_flush(console_pl011_t *console)
+	 * Function to force a write of all buffered
+	 * data that hasn't been output.
+	 * In : x0 - pointer to console_t structure
+	 * Out : return -1 on error else return 0.
+	 * Clobber list : x0, x1
+	 * ---------------------------------------------
+	 */
+func console_pl011_flush
+#if ENABLE_ASSERTIONS
+	cmp	x0, #0
+	ASM_ASSERT(ne)
+#endif /* ENABLE_ASSERTIONS */
+	ldr	x0, [x0, #CONSOLE_T_PL011_BASE]
+	b	console_pl011_core_flush
+endfunc console_pl011_flush
diff --git a/include/drivers/arm/pl011.h b/include/drivers/arm/pl011.h
index cd259c5..06d7543 100644
--- a/include/drivers/arm/pl011.h
+++ b/include/drivers/arm/pl011.h
@@ -7,6 +7,8 @@
 #ifndef __PL011_H__
 #define __PL011_H__
 
+#include <console.h>
+
 /* PL011 Registers */
 #define UARTDR                    0x000
 #define UARTRSR                   0x004
@@ -79,4 +81,26 @@
 
 #endif /* !PL011_GENERIC_UART */
 
+#define CONSOLE_T_PL011_BASE	CONSOLE_T_DRVDATA
+
+#ifndef __ASSEMBLY__
+
+#include <types.h>
+
+typedef struct {
+	console_t console;
+	uintptr_t base;
+} console_pl011_t;
+
+/*
+ * Initialize a new PL011 console instance and register it with the console
+ * framework. The |console| pointer must point to storage that will be valid
+ * for the lifetime of the console, such as a global or static local variable.
+ * Its contents will be reinitialized from scratch.
+ */
+int console_pl011_register(uintptr_t baseaddr, uint32_t clock, uint32_t baud,
+			   console_pl011_t *console);
+
+#endif /*__ASSEMBLY__*/
+
 #endif	/* __PL011_H__ */