meson: console: Introduce console driver
It has only been tested with a system clock of 24 MHz.
It has only been implemented for the multi console API.
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
diff --git a/drivers/meson/console/aarch64/meson_console.S b/drivers/meson/console/aarch64/meson_console.S
new file mode 100644
index 0000000..594d517
--- /dev/null
+++ b/drivers/meson/console/aarch64/meson_console.S
@@ -0,0 +1,263 @@
+/*
+ * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <asm_macros.S>
+#include <assert_macros.S>
+#include <console_macros.S>
+#include <meson_console.h>
+
+ .globl console_meson_register
+ .globl console_meson_init
+ .globl console_meson_putc
+ .globl console_meson_getc
+ .globl console_meson_flush
+ .globl console_meson_core_putc
+ .globl console_meson_core_getc
+ .globl console_meson_core_flush
+
+ /* -----------------------------------------------
+ * Hardware definitions
+ * -----------------------------------------------
+ */
+#define MESON_WFIFO_OFFSET 0x0
+#define MESON_RFIFO_OFFSET 0x4
+#define MESON_CONTROL_OFFSET 0x8
+#define MESON_STATUS_OFFSET 0xC
+#define MESON_MISC_OFFSET 0x10
+#define MESON_REG5_OFFSET 0x14
+
+#define MESON_CONTROL_CLR_ERROR_BIT 24
+#define MESON_CONTROL_RX_RESET_BIT 23
+#define MESON_CONTROL_TX_RESET_BIT 22
+#define MESON_CONTROL_RX_ENABLE_BIT 13
+#define MESON_CONTROL_TX_ENABLE_BIT 12
+
+#define MESON_STATUS_RX_EMPTY_BIT 20
+#define MESON_STATUS_TX_FULL_BIT 21
+#define MESON_STATUS_TX_EMPTY_BIT 22
+
+#define MESON_REG5_USE_XTAL_CLK_BIT 24
+#define MESON_REG5_USE_NEW_RATE_BIT 23
+#define MESON_REG5_NEW_BAUD_RATE_MASK 0x7FFFFF
+
+ /* -----------------------------------------------
+ * int console_meson_register(uintptr_t base,
+ * uint32_t clk, uint32_t baud,
+ * console_meson_t *console);
+ * Function to initialize and register a new MESON
+ * 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_meson_t struct
+ * Out: return 1 on success, 0 on error
+ * Clobber list : x0, x1, x2, x6, x7, x14
+ * -----------------------------------------------
+ */
+func console_meson_register
+ mov x7, x30
+ mov x6, x3
+ cbz x6, register_fail
+ str x0, [x6, #CONSOLE_T_MESON_BASE]
+
+ bl console_meson_init
+ cbz x0, register_fail
+
+ mov x0, x6
+ mov x30, x7
+ finish_console_register meson putc=1, getc=1, flush=1
+
+register_fail:
+ ret x7
+endfunc console_meson_register
+
+ /* -----------------------------------------------
+ * int console_meson_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: x0 - console base address
+ * w1 - Uart clock in Hz
+ * w2 - Baud rate
+ * Out: return 1 on success else 0 on error
+ * Clobber list : x0-x3
+ * -----------------------------------------------
+ */
+func console_meson_init
+ cmp w0, #0
+ beq init_fail
+ mov_imm w3, 24000000 /* TODO: This only works with a 24 MHz clock. */
+ cmp w1, w3
+ bne init_fail
+ cmp w2, #0
+ beq init_fail
+ /* Set baud rate: value = ((clock / 3) / baudrate) - 1 */
+ mov w3, #3
+ udiv w3, w1, w3
+ udiv w3, w3, w2
+ sub w3, w3, #1
+ orr w3, w3, #((1 << MESON_REG5_USE_XTAL_CLK_BIT) | \
+ (1 << MESON_REG5_USE_NEW_RATE_BIT))
+ str w3, [x0, #MESON_REG5_OFFSET]
+ /* Reset UART and clear error flag */
+ ldr w3, [x0, #MESON_CONTROL_OFFSET]
+ orr w3, w3, #((1 << MESON_CONTROL_CLR_ERROR_BIT) | \
+ (1 << MESON_CONTROL_RX_RESET_BIT) | \
+ (1 << MESON_CONTROL_TX_RESET_BIT))
+ str w3, [x0, #MESON_CONTROL_OFFSET]
+ bic w3, w3, #((1 << MESON_CONTROL_CLR_ERROR_BIT) | \
+ (1 << MESON_CONTROL_RX_RESET_BIT) | \
+ (1 << MESON_CONTROL_TX_RESET_BIT))
+ str w3, [x0, #MESON_CONTROL_OFFSET]
+ /* Enable transfer and receive FIFO */
+ orr w3, w3, #((1 << MESON_CONTROL_RX_ENABLE_BIT) | \
+ (1 << MESON_CONTROL_TX_ENABLE_BIT))
+ str w3, [x0, #MESON_CONTROL_OFFSET]
+ /* Success */
+ mov w0, #1
+ ret
+init_fail:
+ mov w0, wzr
+ ret
+endfunc console_meson_init
+
+ /* --------------------------------------------------------
+ * int console_meson_putc(int c, console_meson_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_meson_putc
+#if ENABLE_ASSERTIONS
+ cmp x1, #0
+ ASM_ASSERT(ne)
+#endif /* ENABLE_ASSERTIONS */
+ ldr x1, [x1, #CONSOLE_T_MESON_BASE]
+ b console_meson_core_putc
+endfunc console_meson_putc
+
+ /* --------------------------------------------------------
+ * int console_meson_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
+ * x1 - console base address
+ * Out : return -1 on error else return character.
+ * Clobber list : x2
+ * --------------------------------------------------------
+ */
+func console_meson_core_putc
+#if ENABLE_ASSERTIONS
+ cmp x1, #0
+ ASM_ASSERT(ne)
+#endif
+ /* Prepend '\r' to '\n' */
+ cmp w0, #0xA
+ b.ne 2f
+ /* Wait until the transmit FIFO isn't full */
+1: ldr w2, [x1, #MESON_STATUS_OFFSET]
+ tbnz w2, #MESON_STATUS_TX_FULL_BIT, 1b
+ /* Write '\r' if needed */
+ mov w2, #0xD
+ str w2, [x1, #MESON_WFIFO_OFFSET]
+ /* Wait until the transmit FIFO isn't full */
+2: ldr w2, [x1, #MESON_STATUS_OFFSET]
+ tbnz w2, #MESON_STATUS_TX_FULL_BIT, 2b
+ /* Write input character */
+ str w0, [x1, #MESON_WFIFO_OFFSET]
+ ret
+endfunc console_meson_core_putc
+
+ /* ---------------------------------------------
+ * int console_meson_getc(console_meson_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_meson_getc
+#if ENABLE_ASSERTIONS
+ cmp x0, #0
+ ASM_ASSERT(ne)
+#endif /* ENABLE_ASSERTIONS */
+ ldr x0, [x0, #CONSOLE_T_MESON_BASE]
+ b console_meson_core_getc
+endfunc console_meson_getc
+
+ /* ---------------------------------------------
+ * int console_meson_core_getc(uintptr_t base_addr)
+ * Function to get a character from the console.
+ * It returns the character grabbed on success
+ * 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_meson_core_getc
+#if ENABLE_ASSERTIONS
+ cmp x0, #0
+ ASM_ASSERT(ne)
+#endif
+ /* Is the receive FIFO empty? */
+ ldr w1, [x0, #MESON_STATUS_OFFSET]
+ tbnz w1, #MESON_STATUS_RX_EMPTY_BIT, 1f
+ /* Read one character from the RX FIFO */
+ ldr w0, [x0, #MESON_RFIFO_OFFSET]
+ ret
+1:
+ mov w0, #ERROR_NO_PENDING_CHAR
+ ret
+endfunc console_meson_core_getc
+
+ /* ---------------------------------------------
+ * int console_meson_flush(console_meson_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_meson_flush
+#if ENABLE_ASSERTIONS
+ cmp x0, #0
+ ASM_ASSERT(ne)
+#endif /* ENABLE_ASSERTIONS */
+ ldr x0, [x0, #CONSOLE_T_MESON_BASE]
+ b console_meson_core_flush
+endfunc console_meson_flush
+
+ /* ---------------------------------------------
+ * int console_meson_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
+ * Out : return -1 on error else return 0.
+ * Clobber list : x0, x1
+ * ---------------------------------------------
+ */
+func console_meson_core_flush
+#if ENABLE_ASSERTIONS
+ cmp x0, #0
+ ASM_ASSERT(ne)
+#endif
+ /* Wait until the transmit FIFO is empty */
+1: ldr w1, [x0, #MESON_STATUS_OFFSET]
+ tbz w1, #MESON_STATUS_TX_EMPTY_BIT, 1b
+ mov w0, #0
+ ret
+endfunc console_meson_core_flush
diff --git a/include/drivers/meson/meson_console.h b/include/drivers/meson/meson_console.h
new file mode 100644
index 0000000..759571d
--- /dev/null
+++ b/include/drivers/meson/meson_console.h
@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef MESON_CONSOLE_H
+#define MESON_CONSOLE_H
+
+#include <console.h>
+
+#define CONSOLE_T_MESON_BASE CONSOLE_T_DRVDATA
+
+#ifndef __ASSEMBLY__
+
+#include <stdint.h>
+
+typedef struct {
+ console_t console;
+ uintptr_t base;
+} console_meson_t;
+
+/*
+ * Initialize a new meson 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.
+ *
+ * NOTE: The clock is actually fixed to 24 MHz. The argument is only there in
+ * order to make this function future-proof.
+ */
+int console_meson_register(uintptr_t baseaddr, uint32_t clock, uint32_t baud,
+ console_meson_t *console);
+
+#endif /*__ASSEMBLY__*/
+
+#endif /* MESON_CONSOLE_H */