drivers: cadence: cdns: Update CDNS driver to support MULTI_CONSOLE_API

This patch updates the Cadence CDNS 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: I2ef8fb0d6ab72696997db1e0243a533499569d6b
Signed-off-by: Julius Werner <jwerner@chromium.org>

drivers/cadence/uart/aarch64/cdns_console.S

@@ -5,16 +5,22 @@
  */
 #include <arch.h>
 #include <asm_macros.S>
+#include <assert_macros.S>
 #include <cadence/cdns_uart.h>
 
-	.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_cdns_core_init
+	.globl console_cdns_core_putc
+	.globl console_cdns_core_getc
+
+	.globl  console_cdns_putc
+	.globl  console_cdns_getc
 
 	/* -----------------------------------------------
-	 * int console_core_init(unsigned long base_addr,
-	 * unsigned int uart_clk, unsigned int baud_rate)
+	 * int console_cdns_core_init(uintptr_t base_addr)
 	 * Function to initialize the console without a
 	 * C Runtime to print debug information. This
 	 * function will be accessed by console_init and
@@ -23,18 +29,13 @@
 	 * the HW (baud, ...) and only enable the trans-
 	 * mitter and receiver here.
 	 * In: x0 - console base address
-	 *     w1 - Uart clock in Hz
-	 *     w2 - Baud rate
 	 * Out: return 1 on success else 0 on error
 	 * Clobber list : x1, x2, x3
 	 * -----------------------------------------------
 	 */
-func console_core_init
+func console_cdns_core_init
 	/* Check the input base address */
 	cbz	x0, core_init_fail
-	/* Check baud rate and uart clock for sanity */
-	cbz	w1, core_init_fail
-	cbz	w2, core_init_fail
 
 	/* RX/TX enabled & reset */
 	mov	w3, #(R_UART_CR_TX_EN | R_UART_CR_RX_EN | R_UART_CR_TXRST | R_UART_CR_RXRST)
@@ -45,10 +46,51 @@ func console_core_init
 core_init_fail:
 	mov	w0, wzr
 	ret
-endfunc console_core_init
+endfunc console_cdns_core_init
+
+#if MULTI_CONSOLE_API
+	.globl console_cdns_register
+
+	/* -----------------------------------------------
+	 * int console_cdns_register(console_cdns_t *console,
+		uintptr_t base, uint32_t clk, uint32_t baud)
+	 * Function to initialize and register a new CDNS
+	 * console. Storage passed in for the console struct
+	 * *must* be persistent (i.e. not from the stack).
+	 * In: x0 - UART register base address
+	 *     x1 - pointer to empty console_cdns_t struct
+	 * Out: return 1 on success, 0 on error
+	 * Clobber list : x0, x1, x2, x6, x7, x14
+	 * -----------------------------------------------
+	 */
+func console_cdns_register
+	mov	x7, x30
+	mov	x6, x1
+	cbz	x6, register_fail
+	str	x0, [x6, #CONSOLE_T_CDNS_BASE]
+
+	bl	console_cdns_core_init
+	cbz	x0, register_fail
+
+	mov	x0, x6
+	mov	x30, v7
+	finish_console_register cdns
+
+register_fail:
+	ret	x7
+endfunc console_cdns_register
+#else
+	.globl console_core_init
+	.globl console_core_putc
+	.globl console_core_getc
+	.globl console_core_flush
+	.equ console_core_init,console_cdns_core_init
+	.equ console_core_putc,console_cdns_core_putc
+	.equ console_core_getc,console_cdns_core_getc
+#endif
 
 	/* --------------------------------------------------------
-	 * int console_core_putc(int c, unsigned long base_addr)
+	 * int console_cdns_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
@@ -57,9 +99,12 @@ endfunc console_core_init
 	 * Clobber list : x2
 	 * --------------------------------------------------------
 	 */
-func console_core_putc
-	/* Check the input parameter */
-	cbz	x1, putc_error
+func console_cdns_core_putc
+#if ENABLE_ASSERTIONS
+	cmp	x1, #0
+	ASM_ASSERT(ne)
+#endif /* ENABLE_ASSERTIONS */
+
 	/* Prepend '\r' to '\n' */
 	cmp	w0, #0xA
 	b.ne	2f
@@ -75,36 +120,76 @@ func console_core_putc
 	tbnz	w2, #UART_SR_INTR_TFUL_BIT, 2b
 	str	w0, [x1, #R_UART_TX]
 	ret
-putc_error:
-	mov	w0, #-1
-	ret
-endfunc console_core_putc
+endfunc console_cdns_core_putc
+
+	/* --------------------------------------------------------
+	 * int console_cdns_putc(int c, console_cdns_t *cdns)
+	 * 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_cdns_putc
+#if ENABLE_ASSERTIONS
+	cmp	x1, #0
+	ASM_ASSERT(ne)
+#endif /* ENABLE_ASSERTIONS */
+	ldr	x1, [x1, #CONSOLE_T_CDNS_BASE]
+	b	console_cdns_core_putc
+endfunc console_cdns_putc
 
 	/* ---------------------------------------------
-	 * int console_core_getc(unsigned long base_addr)
+	 * int console_cdns_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_cdns_core_getc
+#if ENABLE_ASSERTIONS
+	cmp	x0, #0
+	ASM_ASSERT(ne)
+#endif /* ENABLE_ASSERTIONS */
+
 	/* Check if the receive FIFO is empty */
 	ldr	w1, [x0, #R_UART_SR]
-	tbnz	w1, #UART_SR_INTR_REMPTY_BIT, 1b
+	tbnz	w1, #UART_SR_INTR_REMPTY_BIT, no_char
 	ldr	w1, [x0, #R_UART_RX]
 	mov	w0, w1
 	ret
-getc_error:
-	mov	w0, #-1
+no_char:
+	mov	w0, #ERROR_NO_PENDING_CHAR
 	ret
-endfunc console_core_getc
+endfunc console_cdns_core_getc
+
+	/* ---------------------------------------------
+	 * int console_cdns_getc(console_cdns_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_cdns_getc
+#if ENABLE_ASSERTIONS
+	cmp	x0, #0
+	ASM_ASSERT(ne)
+#endif /* ENABLE_ASSERTIONS */
+	ldr	x0, [x0, #CONSOLE_T_CDNS_BASE]
+	b	console_cdns_core_getc
+endfunc console_cdns_getc
 
 	/* ---------------------------------------------
 	 * int console_core_flush(uintptr_t base_addr)
+	 * DEPRECATED: Not used with MULTI_CONSOLE_API!
 	 * Function to force a write of all buffered
 	 * data that hasn't been output.
 	 * In : x0 - console base address

include/drivers/cadence/cdns_uart.h

@@ -7,6 +7,8 @@
 #ifndef __CADENCE_UART_H__
 #define __CADENCE_UART_H__
 
+#include <console.h>
+
 /* This is very minimalistic and will only work in QEMU.  */
 
 /* CADENCE Registers */
@@ -23,4 +25,26 @@
 #define R_UART_TX	0x30
 #define R_UART_RX	0x30
 
+#define CONSOLE_T_CDNS_BASE	CONSOLE_T_DRVDATA
+
+#ifndef __ASSEMBLY__
+
+#include <types.h>
+
+typedef struct {
+	console_t console;
+	uintptr_t base;
+} console_cdns_t;
+
+/*
+ * Initialize a new Cadence 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_cdns_register(uint64_t baseaddr, uint32_t clock, uint32_t baud,
+			  console_cdns_t *console);
+
+#endif /*__ASSEMBLY__*/
+
 #endif