148 lines
3.0 KiB
C
148 lines
3.0 KiB
C
/* GRLIB APBUART Serial controller driver
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*
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* (C) Copyright 2007, 2015
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* Daniel Hellstrom, Cobham Gaisler, 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/io.h>
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#include <ambapp.h>
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#include <grlib/apbuart.h>
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#include <serial.h>
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#include <watchdog.h>
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DECLARE_GLOBAL_DATA_PTR;
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/* Select which UART that will become u-boot console */
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#ifndef CONFIG_SYS_GRLIB_APBUART_INDEX
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#define CONFIG_SYS_GRLIB_APBUART_INDEX 0
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#endif
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static int leon3_serial_init(void)
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{
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ambapp_dev_apbuart *uart;
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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_find(&ambapp_plb, VENDOR_GAISLER, GAISLER_APBUART,
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CONFIG_SYS_GRLIB_APBUART_INDEX, &apbdev) != 1)
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return -1; /* didn't find hardware */
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/* found apbuart, let's init .. */
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uart = (ambapp_dev_apbuart *) apbdev.address;
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/* Set scaler / baud rate */
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tmp = (((CONFIG_SYS_CLK_FREQ*10) / (CONFIG_BAUDRATE*8)) - 5)/10;
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writel(tmp, &uart->scaler);
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/* Let bit 11 be unchanged (debug bit for GRMON) */
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tmp = readl(&uart->ctrl) & APBUART_CTRL_DBG;
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/* Receiver & transmitter enable */
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tmp |= APBUART_CTRL_RE | APBUART_CTRL_TE;
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writel(tmp, &uart->ctrl);
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gd->arch.uart = uart;
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return 0;
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}
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static inline ambapp_dev_apbuart *leon3_get_uart_regs(void)
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{
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ambapp_dev_apbuart *uart = gd->arch.uart;
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return uart;
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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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ambapp_dev_apbuart * const uart = leon3_get_uart_regs();
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if (!uart)
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return;
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/* Wait for last character to go. */
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while (!(readl(&uart->status) & APBUART_STATUS_THE))
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WATCHDOG_RESET();
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/* Send data */
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writel(c, &uart->data);
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#ifdef LEON_DEBUG
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/* Wait for data to be sent */
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while (!(readl(&uart->status) & APBUART_STATUS_TSE))
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WATCHDOG_RESET();
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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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ambapp_dev_apbuart * const uart = leon3_get_uart_regs();
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if (!uart)
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return 0;
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/* Wait for a character to arrive. */
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while (!(readl(&uart->status) & APBUART_STATUS_DR))
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WATCHDOG_RESET();
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/* Read character data */
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return readl(&uart->data);
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}
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static int leon3_serial_tstc(void)
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{
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ambapp_dev_apbuart * const uart = leon3_get_uart_regs();
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if (!uart)
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return 0;
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return readl(&uart->status) & APBUART_STATUS_DR;
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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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ambapp_dev_apbuart * const uart = leon3_get_uart_regs();
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unsigned int scaler;
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if (!uart)
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return;
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if (!gd->baudrate)
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gd->baudrate = CONFIG_BAUDRATE;
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scaler = (((CONFIG_SYS_CLK_FREQ*10) / (gd->baudrate*8)) - 5)/10;
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writel(scaler, &uart->scaler);
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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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