129 lines
2.6 KiB
C
129 lines
2.6 KiB
C
/* GRLIB APBUART Serial controller driver
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*
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* (C) Copyright 2007
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* Daniel Hellstrom, Gaisler Research, daniel@gaisler.com.
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*
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* SPDX-License-Identifier: GPL-2.0+
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*/
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#include <common.h>
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#include <asm/processor.h>
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#include <asm/leon.h>
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#include <ambapp.h>
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#include <serial.h>
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#include <linux/compiler.h>
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DECLARE_GLOBAL_DATA_PTR;
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ambapp_dev_apbuart *leon3_apbuart = NULL;
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static int leon3_serial_init(void)
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{
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ambapp_apbdev apbdev;
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unsigned int tmp;
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/* find UART */
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if (ambapp_apb_first(VENDOR_GAISLER, GAISLER_APBUART, &apbdev) == 1) {
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leon3_apbuart = (ambapp_dev_apbuart *) apbdev.address;
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/* found apbuart, let's init...
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*
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* Set scaler / baud rate
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*
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* Receiver & transmitter enable
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*/
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leon3_apbuart->scaler = CONFIG_SYS_GRLIB_APBUART_SCALER;
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/* Let bit 11 be unchanged (debug bit for GRMON) */
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tmp = READ_WORD(leon3_apbuart->ctrl);
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leon3_apbuart->ctrl = ((tmp & LEON_REG_UART_CTRL_DBG) |
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LEON_REG_UART_CTRL_RE |
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LEON_REG_UART_CTRL_TE);
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return 0;
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}
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return -1; /* didn't find hardware */
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}
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static void leon3_serial_putc_raw(const char c)
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{
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if (!leon3_apbuart)
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return;
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/* Wait for last character to go. */
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while (!(READ_WORD(leon3_apbuart->status) & LEON_REG_UART_STATUS_THE)) ;
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/* Send data */
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leon3_apbuart->data = c;
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#ifdef LEON_DEBUG
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/* Wait for data to be sent */
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while (!(READ_WORD(leon3_apbuart->status) & LEON_REG_UART_STATUS_TSE)) ;
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#endif
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}
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static void leon3_serial_putc(const char c)
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{
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if (c == '\n')
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leon3_serial_putc_raw('\r');
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leon3_serial_putc_raw(c);
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}
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static int leon3_serial_getc(void)
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{
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if (!leon3_apbuart)
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return 0;
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/* Wait for a character to arrive. */
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while (!(READ_WORD(leon3_apbuart->status) & LEON_REG_UART_STATUS_DR)) ;
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/* read data */
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return READ_WORD(leon3_apbuart->data);
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}
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static int leon3_serial_tstc(void)
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{
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if (leon3_apbuart)
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return (READ_WORD(leon3_apbuart->status) &
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LEON_REG_UART_STATUS_DR);
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return 0;
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}
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/* set baud rate for uart */
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static void leon3_serial_setbrg(void)
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{
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/* update baud rate settings, read it from gd->baudrate */
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unsigned int scaler;
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if (leon3_apbuart && (gd->baudrate > 0)) {
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scaler =
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(((CONFIG_SYS_CLK_FREQ * 10) / (gd->baudrate * 8)) -
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5) / 10;
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leon3_apbuart->scaler = scaler;
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}
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return;
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}
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static struct serial_device leon3_serial_drv = {
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.name = "leon3_serial",
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.start = leon3_serial_init,
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.stop = NULL,
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.setbrg = leon3_serial_setbrg,
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.putc = leon3_serial_putc,
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.puts = default_serial_puts,
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.getc = leon3_serial_getc,
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.tstc = leon3_serial_tstc,
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};
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void leon3_serial_initialize(void)
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{
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serial_register(&leon3_serial_drv);
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}
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__weak struct serial_device *default_serial_console(void)
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{
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return &leon3_serial_drv;
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}
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