From 19112b795e5040a9b0e101736864f5d404c215fe Mon Sep 17 00:00:00 2001 From: Konstantin Porotchkin Date: Mon, 8 Oct 2018 16:50:54 +0300 Subject: [PATCH] drivers: marvell Add support for Armada-37xx UART Introduce driver for Marvell Armada-37xx UART console Signed-off-by: Konstantin Porotchkin --- drivers/marvell/uart/a3700_console.S | 168 +++++++++++++++++++++++++++ drivers/marvell/uart/a3700_console.h | 55 +++++++++ 2 files changed, 223 insertions(+) create mode 100644 drivers/marvell/uart/a3700_console.S create mode 100644 drivers/marvell/uart/a3700_console.h diff --git a/drivers/marvell/uart/a3700_console.S b/drivers/marvell/uart/a3700_console.S new file mode 100644 index 00000000..6575af47 --- /dev/null +++ b/drivers/marvell/uart/a3700_console.S @@ -0,0 +1,168 @@ +/* + * Copyright (C) 2016 Marvell International Ltd. + * + * SPDX-License-Identifier: BSD-3-Clause + * https://spdx.org/licenses + */ + +#include +#include + + .globl console_core_init + .globl console_core_putc + .globl console_core_getc + .globl console_core_flush + + /* ----------------------------------------------- + * int console_core_init(unsigned long 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 + * Clobber list : x1, x2, x3 + * ----------------------------------------------- + */ +func console_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 w2, w2, #0x3ff + + ldr w3, [x0, #UART_BAUD_REG] + bic w3, w3, 0x3ff + orr w3, w3, w2 + str w3, [x0, #UART_BAUD_REG]/* set baud rate divisor */ + + /* Set UART to default 16X scheme */ + mov w3, #0 + str w3, [x0, #UART_POSSR_REG] + + /* + * Wait for the TX FIFO to be empty. If wait for 20ms, the TX FIFO is + * still not empty, TX FIFO will reset by all means. + */ + mov w1, #20 /* max time out 20ms */ +2: + /* Check whether TX FIFO is empty */ + ldr w3, [x0, #UART_STATUS_REG] + and w3, w3, #UARTLSR_TXFIFOEMPTY + cmp w3, #0 + b.ne 4f + + /* Delay */ + mov w2, #30000 +3: + sub w2, w2, #1 + cmp w2, #0 + b.ne 3b + + /* Check whether 10ms is waited */ + sub w1, w1, #1 + cmp w1, #0 + b.ne 2b + +4: + /* Reset FIFO */ + mov w3, #UART_CTRL_RXFIFO_RESET + orr w3, w3, #UART_CTRL_TXFIFO_RESET + str w3, [x0, #UART_CTRL_REG] + + /* Delay */ + mov w2, #2000 +1: + sub w2, w2, #1 + cmp w2, #0 + b.ne 1b + + /* No Parity, 1 Stop */ + mov w3, #0 + str w3, [x0, #UART_CTRL_REG] + + mov w0, #1 + ret +init_fail: + mov w0, #0 + ret +endfunc console_core_init + + /* -------------------------------------------------------- + * int console_core_putc(int c, unsigned int 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_core_putc + /* Check the input parameter */ + cbz x1, putc_error + + /* Prepend '\r' to '\n' */ + cmp w0, #0xA + b.ne 2f + /* Check if the transmit FIFO is full */ +1: ldr w2, [x1, #UART_STATUS_REG] + and w2, w2, #UARTLSR_TXFIFOFULL + cmp w2, #UARTLSR_TXFIFOFULL + b.eq 1b + mov w2, #0xD /* '\r' */ + str w2, [x1, #UART_TX_REG] + + /* Check if the transmit FIFO is full */ +2: ldr w2, [x1, #UART_STATUS_REG] + and w2, w2, #UARTLSR_TXFIFOFULL + cmp w2, #UARTLSR_TXFIFOFULL + b.eq 2b + str w0, [x1, #UART_TX_REG] + ret +putc_error: + mov w0, #-1 + ret +endfunc console_core_putc + + /* --------------------------------------------- + * int console_core_getc(void) + * Function to get a character from the console. + * It returns the character grabbed on success + * or -1 on error. + * In : w0 - console base address + * Out : return -1 on error else return character. + * Clobber list : x0, x1 + * --------------------------------------------- + */ +func console_core_getc + /* Check if the receive FIFO is empty */ + ret +getc_error: + mov w0, #-1 + ret +endfunc console_core_getc + + /* --------------------------------------------- + * int console_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_core_flush + /* Placeholder */ + mov w0, #0 + ret +endfunc console_core_flush diff --git a/drivers/marvell/uart/a3700_console.h b/drivers/marvell/uart/a3700_console.h new file mode 100644 index 00000000..1831360e --- /dev/null +++ b/drivers/marvell/uart/a3700_console.h @@ -0,0 +1,55 @@ +/* + * Copyright (C) 2016 Marvell International Ltd. + * + * SPDX-License-Identifier: BSD-3-Clause + * https://spdx.org/licenses + */ + +#ifndef __A3700_CONSOLE_H__ +#define __A3700_CONSOLE_H__ + +/* MVEBU UART Registers */ +#define UART_RX_REG 0x00 +#define UART_TX_REG 0x04 +#define UART_CTRL_REG 0x08 +#define UART_STATUS_REG 0x0c +#define UART_BAUD_REG 0x10 +#define UART_POSSR_REG 0x14 + +/* 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 */ + +/* 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_TXFIFOFULL (1 << 11) /* Tx Fifo Full */ + +/* UART Control Register bits */ +#define UART_CTRL_RXFIFO_RESET (1 << 14) +#define UART_CTRL_TXFIFO_RESET (1 << 15) +#define UARTLSR_TXFIFOEMPTY (1 << 6) + +#endif /* __A3700_CONSOLE_H__ */ -- 2.30.2