mirror of
https://github.com/AsahiLinux/u-boot
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147 lines
3.1 KiB
C
147 lines
3.1 KiB
C
/* GRLIB APBUART Serial controller driver
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*
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* (C) Copyright 2008, 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 <serial.h>
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#include <watchdog.h>
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DECLARE_GLOBAL_DATA_PTR;
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static unsigned leon2_serial_calc_scaler(unsigned freq, unsigned baud)
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{
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return (((freq*10) / (baud*8)) - 5) / 10;
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}
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static int leon2_serial_init(void)
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{
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LEON2_regs *leon2 = (LEON2_regs *)LEON2_PREGS;
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LEON2_Uart_regs *regs;
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unsigned int tmp;
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#if LEON2_CONSOLE_SELECT == LEON_CONSOLE_UART1
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regs = (LEON2_Uart_regs *)&leon2->UART_Channel_1;
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#else
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regs = (LEON2_Uart_regs *)&leon2->UART_Channel_2;
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#endif
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/* Set scaler / baud rate */
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tmp = leon2_serial_calc_scaler(CONFIG_SYS_CLK_FREQ, CONFIG_BAUDRATE);
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writel(tmp, ®s->UART_Scaler);
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/* Let bit 11 be unchanged (debug bit for GRMON) */
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tmp = readl(®s->UART_Control) & LEON2_UART_CTRL_DBG;
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tmp |= (LEON2_UART1_LOOPBACK_ENABLE << 7);
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tmp |= (LEON2_UART1_FLOWCTRL_ENABLE << 6);
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tmp |= (LEON2_UART1_PARITY_ENABLE << 5);
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tmp |= (LEON2_UART1_ODDPAR_ENABLE << 4);
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/* Receiver & transmitter enable */
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tmp |= (LEON2_UART_CTRL_RE | LEON2_UART_CTRL_TE);
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writel(tmp, ®s->UART_Control);
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gd->arch.uart = regs;
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return 0;
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}
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static inline LEON2_Uart_regs *leon2_get_uart_regs(void)
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{
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LEON2_Uart_regs *uart = gd->arch.uart;
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return uart;
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}
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static void leon2_serial_putc_raw(const char c)
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{
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LEON2_Uart_regs *uart = leon2_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->UART_Status) & LEON2_UART_STAT_THE))
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WATCHDOG_RESET();
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/* Send data */
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writel(c, &uart->UART_Channel);
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#ifdef LEON_DEBUG
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/* Wait for data to be sent */
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while (!(readl(&uart->UART_Status) & LEON2_UART_STAT_TSE))
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WATCHDOG_RESET();
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#endif
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}
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static void leon2_serial_putc(const char c)
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{
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if (c == '\n')
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leon2_serial_putc_raw('\r');
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leon2_serial_putc_raw(c);
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}
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static int leon2_serial_getc(void)
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{
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LEON2_Uart_regs *uart = leon2_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->UART_Status) & LEON2_UART_STAT_DR))
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WATCHDOG_RESET();
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/* Read character data */
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return readl(&uart->UART_Channel);
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}
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static int leon2_serial_tstc(void)
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{
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LEON2_Uart_regs *uart = leon2_get_uart_regs();
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if (!uart)
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return 0;
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return readl(&uart->UART_Status) & LEON2_UART_STAT_DR;
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}
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static void leon2_serial_setbrg(void)
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{
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LEON2_Uart_regs *uart = leon2_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 = leon2_serial_calc_scaler(CONFIG_SYS_CLK_FREQ, gd->baudrate);
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writel(scaler, &uart->UART_Scaler);
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}
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static struct serial_device leon2_serial_drv = {
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.name = "leon2_serial",
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.start = leon2_serial_init,
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.stop = NULL,
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.setbrg = leon2_serial_setbrg,
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.putc = leon2_serial_putc,
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.puts = default_serial_puts,
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.getc = leon2_serial_getc,
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.tstc = leon2_serial_tstc,
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};
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void leon2_serial_initialize(void)
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{
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serial_register(&leon2_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 &leon2_serial_drv;
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}
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