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 (file)
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 (file)
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 */