summaryrefslogtreecommitdiffstats
path: root/drivers/nxp/console/16550_console.S
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 09:13:47 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 09:13:47 +0000
commit102b0d2daa97dae68d3eed54d8fe37a9cc38a892 (patch)
treebcf648efac40ca6139842707f0eba5a4496a6dd2 /drivers/nxp/console/16550_console.S
parentInitial commit. (diff)
downloadarm-trusted-firmware-upstream/2.8.0+dfsg.tar.xz
arm-trusted-firmware-upstream/2.8.0+dfsg.zip
Adding upstream version 2.8.0+dfsg.upstream/2.8.0+dfsgupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/nxp/console/16550_console.S')
-rw-r--r--drivers/nxp/console/16550_console.S319
1 files changed, 319 insertions, 0 deletions
diff --git a/drivers/nxp/console/16550_console.S b/drivers/nxp/console/16550_console.S
new file mode 100644
index 0000000..044d3d0
--- /dev/null
+++ b/drivers/nxp/console/16550_console.S
@@ -0,0 +1,319 @@
+/*
+ * Copyright (c) 2021, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <arch.h>
+#include <asm_macros.S>
+#include <assert_macros.S>
+#include <console_macros.S>
+
+/* UART16550 Registers */
+#define UARTTX 0x0
+#define UARTRX 0x0
+#define UARTDLL 0x0
+#define UARTIER 0x1
+#define UARTDLLM 0x1
+#define UARTFCR 0x2
+#define UARTLCR 0x3
+#define UARTLSR 0x5
+#define UARTMCR 0x4
+
+/* FIFO Control Register bits */
+#define UARTFCR_FIFOMD_16450 (0 << 6)
+#define UARTFCR_FIFOMD_16550 (1 << 6)
+#define UARTFCR_RXTRIG_1 (0 << 6)
+#define UARTFCR_RXTRIG_4 (1 << 6)
+#define UARTFCR_RXTRIG_8 (2 << 6)
+#define UARTFCR_RXTRIG_16 (3 << 6)
+#define UARTFCR_TXTRIG_1 (0 << 4)
+#define UARTFCR_TXTRIG_4 (1 << 4)
+#define UARTFCR_TXTRIG_8 (2 << 4)
+#define UARTFCR_TXTRIG_16 (3 << 4)
+#define UARTFCR_DMAEN (1 << 3) /* Enable DMA mode */
+#define UARTFCR_TXCLR (1 << 2) /* Clear contents of Tx FIFO */
+#define UARTFCR_RXCLR (1 << 1) /* Clear contents of Rx FIFO */
+#define UARTFCR_FIFOEN (1 << 0) /* Enable the Tx/Rx FIFO */
+#define UARTFCR_64FIFO (1 << 5)
+
+/* Line Control Register bits */
+#define UARTLCR_DLAB (1 << 7) /* Divisor Latch Access */
+#define UARTLCR_SETB (1 << 6) /* Set BREAK Condition */
+#define UARTLCR_SETP (1 << 5) /* Set Parity to LCR[4] */
+#define UARTLCR_EVEN (1 << 4) /* Even Parity Format */
+#define UARTLCR_PAR (1 << 3) /* Parity */
+#define UARTLCR_STOP (1 << 2) /* Stop Bit */
+#define UARTLCR_WORDSZ_5 0 /* Word Length of 5 */
+#define UARTLCR_WORDSZ_6 1 /* Word Length of 6 */
+#define UARTLCR_WORDSZ_7 2 /* Word Length of 7 */
+#define UARTLCR_WORDSZ_8 3 /* Word Length of 8 */
+
+/* Line Status Register bits */
+#define UARTLSR_RXFIFOEMT (1 << 9) /* Rx Fifo Empty */
+#define UARTLSR_TXFIFOFULL (1 << 8) /* Tx Fifo Full */
+#define UARTLSR_RXFIFOERR (1 << 7) /* Rx Fifo Error */
+#define UARTLSR_TEMT (1 << 6) /* Tx Shift Register Empty */
+#define UARTLSR_THRE (1 << 5) /* Tx Holding Register Empty */
+#define UARTLSR_BRK (1 << 4) /* Break Condition Detected */
+#define UARTLSR_FERR (1 << 3) /* Framing Error */
+#define UARTLSR_PERR (1 << 3) /* Parity Error */
+#define UARTLSR_OVRF (1 << 2) /* Rx Overrun Error */
+#define UARTLSR_RDR (1 << 2) /* Rx Data Ready */
+
+#define CONSOLE_T_16550_BASE CONSOLE_T_BASE
+
+ /*
+ * "core" functions are low-level implementations that don't require
+ * writable memory and are thus safe to call in BL1 crash context.
+ */
+ .globl nxp_console_16550_core_init
+ .globl nxp_console_16550_core_putc
+ .globl nxp_console_16550_core_getc
+ .globl nxp_console_16550_core_flush
+
+ .globl console_16550_putc
+ .globl console_16550_getc
+ .globl console_16550_flush
+
+ /* -----------------------------------------------
+ * int nxp_console_16550_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: x0 - console base address
+ * w1 - Uart clock in Hz
+ * w2 - Baud rate
+ * Out: return 1 on success, 0 on error
+ * Clobber list : x1, x2, x3
+ * -----------------------------------------------
+ */
+func nxp_console_16550_core_init
+ /* Check the input base address */
+ cbz x0, init_fail
+ /* Check baud rate and uart clock for sanity */
+ cbz w1, init_fail
+ cbz w2, init_fail
+
+ /* Program the baudrate */
+ /* Divisor = Uart clock / (16 * baudrate) */
+ lsl w2, w2, #4
+ udiv w2, w1, w2
+ and w1, w2, #0xff /* w1 = DLL */
+ lsr w2, w2, #8
+ and w2, w2, #0xff /* w2 = DLLM */
+ ldrb w3, [x0, #UARTLCR]
+ orr w3, w3, #UARTLCR_DLAB
+ strb w3, [x0, #UARTLCR] /* enable DLL, DLLM programming */
+ strb w1, [x0, #UARTDLL] /* program DLL */
+ strb w2, [x0, #UARTDLLM] /* program DLLM */
+ mov w2, #~UARTLCR_DLAB
+ and w3, w3, w2
+ strb w3, [x0, #UARTLCR] /* disable DLL, DLLM programming */
+
+ /* 8n1 */
+ mov w3, #3
+ strb w3, [x0, #UARTLCR]
+ /* no interrupt */
+ mov w3, #0
+ strb w3, [x0, #UARTIER]
+ /* enable fifo, DMA */
+ mov w3, #(UARTFCR_FIFOEN |UARTFCR_TXCLR | UARTFCR_RXCLR)
+ strb w3, [x0, #UARTFCR]
+ /* DTR + RTS */
+ mov w3, #3
+ str w3, [x0, #UARTMCR]
+ mov w0, #1
+ ret
+init_fail:
+ mov w0, #0
+ ret
+endfunc nxp_console_16550_core_init
+
+ .globl nxp_console_16550_register
+
+ /* -----------------------------------------------
+ * int nxp_console_16550_register(uintptr_t baseaddr,
+ * uint32_t clock, uint32_t baud,
+ * console_t *console);
+ * Function to initialize and register a new 16550
+ * console. Storage passed in for the console struct
+ * *must* be persistent (i.e. not from the stack).
+ * If w1 (UART clock) is 0, initialisation will be
+ * skipped, relying on previous code to have done
+ * this already. w2 is ignored then as well.
+ * In: x0 - UART register base address
+ * w1 - UART clock in Hz
+ * w2 - Baud rate (ignored if w1 is 0)
+ * x3 - pointer to empty console_t struct
+ * Out: return 1 on success, 0 on error
+ * Clobber list : x0, x1, x2, x6, x7, x14
+ * -----------------------------------------------
+ */
+func nxp_console_16550_register
+ mov x7, x30
+ mov x6, x3
+ cbz x6, register_fail
+ str x0, [x6, #CONSOLE_T_16550_BASE]
+
+ /* A clock rate of zero means to skip the initialisation. */
+ cbz w1, register_16550
+
+ bl nxp_console_16550_core_init
+ cbz x0, register_fail
+
+register_16550:
+ mov x0, x6
+ mov x30, x7
+ finish_console_register 16550 putc=1, getc=1, flush=1
+
+register_fail:
+ ret x7
+endfunc nxp_console_16550_register
+
+ /* --------------------------------------------------------
+ * int console_16550_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 nxp_console_16550_core_putc
+#if ENABLE_ASSERTIONS
+ cmp x1, #0
+ ASM_ASSERT(ne)
+#endif /* ENABLE_ASSERTIONS */
+
+ /* Prepend '\r' to '\n' */
+ cmp w0, #'\n'
+ b.ne 2f
+ /* Check if the transmit FIFO is full */
+1: ldrb w2, [x1, #UARTLSR]
+ and w2, w2, #UARTLSR_THRE /* #(UARTLSR_TEMT | UARTLSR_THRE)*/
+ cmp w2, #(UARTLSR_THRE)
+ b.ne 1b
+ mov w2, #'\r'
+ strb w2, [x1, #UARTTX]
+ ldrb w2, [x1, #UARTFCR]
+ orr w2, w2, #UARTFCR_TXCLR
+
+ /* Check if the transmit FIFO is full */
+2: ldrb w2, [x1, #UARTLSR]
+ and w2, w2, #(UARTLSR_THRE)
+ cmp w2, #(UARTLSR_THRE)
+ b.ne 2b
+ strb w0, [x1, #UARTTX]
+ ret
+endfunc nxp_console_16550_core_putc
+
+ /* --------------------------------------------------------
+ * int console_16550_putc(int c, console_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_16550_putc
+#if ENABLE_ASSERTIONS
+ cmp x1, #0
+ ASM_ASSERT(ne)
+#endif /* ENABLE_ASSERTIONS */
+ ldr x1, [x1, #CONSOLE_T_16550_BASE]
+ b nxp_console_16550_core_putc
+endfunc console_16550_putc
+
+ /* ---------------------------------------------
+ * int console_16550_core_getc(uintptr_t base_addr)
+ * Function to get a character from the console.
+ * It returns the character grabbed on success
+ * or -1 on if no character is available.
+ * In : x0 - console base address
+ * Out : w0 - character if available, else -1
+ * Clobber list : x0, x1
+ * ---------------------------------------------
+ */
+func nxp_console_16550_core_getc
+#if ENABLE_ASSERTIONS
+ cmp x0, #0
+ ASM_ASSERT(ne)
+#endif /* ENABLE_ASSERTIONS */
+
+ /* Check if the receive FIFO is empty */
+1: ldrb w1, [x0, #UARTLSR]
+ tbz w1, #UARTLSR_RDR, 1b
+ ldrb w0, [x0, #UARTRX]
+ ret
+no_char:
+ mov w0, #ERROR_NO_PENDING_CHAR
+ ret
+endfunc nxp_console_16550_core_getc
+
+ /* ---------------------------------------------
+ * int console_16550_getc(console_t *console)
+ * Function to get a character from the console.
+ * It returns the character grabbed on success
+ * or -1 on 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_16550_getc
+#if ENABLE_ASSERTIONS
+ cmp x1, #0
+ ASM_ASSERT(ne)
+#endif /* ENABLE_ASSERTIONS */
+ ldr x0, [x0, #CONSOLE_T_16550_BASE]
+ b nxp_console_16550_core_getc
+endfunc console_16550_getc
+
+ /* ---------------------------------------------
+ * int console_16550_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 nxp_console_16550_core_flush
+#if ENABLE_ASSERTIONS
+ cmp x0, #0
+ ASM_ASSERT(ne)
+#endif /* ENABLE_ASSERTIONS */
+
+ /* Loop until the transmit FIFO is empty */
+1: ldrb w1, [x0, #UARTLSR]
+ and w1, w1, #(UARTLSR_THRE)
+ cmp w1, #(UARTLSR_THRE)
+ b.ne 1b
+
+ mov w0, #0
+ ret
+endfunc nxp_console_16550_core_flush
+
+ /* ---------------------------------------------
+ * int console_16550_flush(console_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_16550_flush
+#if ENABLE_ASSERTIONS
+ cmp x0, #0
+ ASM_ASSERT(ne)
+#endif /* ENABLE_ASSERTIONS */
+ ldr x0, [x0, #CONSOLE_T_16550_BASE]
+ b nxp_console_16550_core_flush
+endfunc console_16550_flush