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https://github.com/brain-hackers/u-boot-brain
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![Bin Meng](/assets/img/avatar_default.png)
When a driver declares DM_FLAG_PRE_RELOC flag, it wishes to be bound before relocation. However due to a bug in the DM core, the flag only takes effect when devices are statically declared via U_BOOT_DEVICE(). This bug has been fixed recently by commit "dm: core: Respect drivers with the DM_FLAG_PRE_RELOC flag in lists_bind_fdt()", but with the fix, it has a side effect that all existing drivers that declared DM_FLAG_PRE_RELOC flag will be bound before relocation now. This may expose potential boot failure on some boards due to insufficient memory during the pre-relocation stage. To mitigate this potential impact, the following changes are implemented: - Remove DM_FLAG_PRE_RELOC flag in the driver, if the driver only supports configuration from device tree (OF_CONTROL) - Keep DM_FLAG_PRE_RELOC flag in the driver only if the device is statically declared via U_BOOT_DEVICE() - Surround DM_FLAG_PRE_RELOC flag with OF_CONTROL check, for drivers that support both statically declared devices and configuration from device tree Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Simon Glass <sjg@chromium.org>
236 lines
5.7 KiB
C
236 lines
5.7 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Copyright (C) 2012 Michal Simek <monstr@monstr.eu>
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* Copyright (C) 2011-2012 Xilinx, Inc. All rights reserved.
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*/
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#include <clk.h>
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#include <common.h>
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#include <debug_uart.h>
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#include <dm.h>
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#include <errno.h>
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#include <fdtdec.h>
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#include <watchdog.h>
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#include <asm/io.h>
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#include <linux/compiler.h>
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#include <serial.h>
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DECLARE_GLOBAL_DATA_PTR;
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#define ZYNQ_UART_SR_TXACTIVE BIT(11) /* TX active */
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#define ZYNQ_UART_SR_TXFULL BIT(4) /* TX FIFO full */
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#define ZYNQ_UART_SR_RXEMPTY BIT(1) /* RX FIFO empty */
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#define ZYNQ_UART_CR_TX_EN BIT(4) /* TX enabled */
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#define ZYNQ_UART_CR_RX_EN BIT(2) /* RX enabled */
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#define ZYNQ_UART_CR_TXRST BIT(1) /* TX logic reset */
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#define ZYNQ_UART_CR_RXRST BIT(0) /* RX logic reset */
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#define ZYNQ_UART_MR_PARITY_NONE 0x00000020 /* No parity mode */
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struct uart_zynq {
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u32 control; /* 0x0 - Control Register [8:0] */
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u32 mode; /* 0x4 - Mode Register [10:0] */
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u32 reserved1[4];
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u32 baud_rate_gen; /* 0x18 - Baud Rate Generator [15:0] */
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u32 reserved2[4];
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u32 channel_sts; /* 0x2c - Channel Status [11:0] */
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u32 tx_rx_fifo; /* 0x30 - FIFO [15:0] or [7:0] */
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u32 baud_rate_divider; /* 0x34 - Baud Rate Divider [7:0] */
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};
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struct zynq_uart_platdata {
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struct uart_zynq *regs;
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};
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/* Set up the baud rate in gd struct */
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static void _uart_zynq_serial_setbrg(struct uart_zynq *regs,
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unsigned long clock, unsigned long baud)
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{
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/* Calculation results. */
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unsigned int calc_bauderror, bdiv, bgen;
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unsigned long calc_baud = 0;
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/* Covering case where input clock is so slow */
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if (clock < 1000000 && baud > 4800)
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baud = 4800;
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/* master clock
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* Baud rate = ------------------
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* bgen * (bdiv + 1)
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*
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* Find acceptable values for baud generation.
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*/
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for (bdiv = 4; bdiv < 255; bdiv++) {
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bgen = clock / (baud * (bdiv + 1));
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if (bgen < 2 || bgen > 65535)
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continue;
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calc_baud = clock / (bgen * (bdiv + 1));
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/*
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* Use first calculated baudrate with
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* an acceptable (<3%) error
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*/
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if (baud > calc_baud)
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calc_bauderror = baud - calc_baud;
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else
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calc_bauderror = calc_baud - baud;
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if (((calc_bauderror * 100) / baud) < 3)
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break;
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}
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writel(bdiv, ®s->baud_rate_divider);
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writel(bgen, ®s->baud_rate_gen);
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}
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/* Initialize the UART, with...some settings. */
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static void _uart_zynq_serial_init(struct uart_zynq *regs)
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{
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/* RX/TX enabled & reset */
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writel(ZYNQ_UART_CR_TX_EN | ZYNQ_UART_CR_RX_EN | ZYNQ_UART_CR_TXRST | \
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ZYNQ_UART_CR_RXRST, ®s->control);
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writel(ZYNQ_UART_MR_PARITY_NONE, ®s->mode); /* 8 bit, no parity */
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}
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static int _uart_zynq_serial_putc(struct uart_zynq *regs, const char c)
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{
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if (readl(®s->channel_sts) & ZYNQ_UART_SR_TXFULL)
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return -EAGAIN;
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writel(c, ®s->tx_rx_fifo);
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return 0;
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}
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static int zynq_serial_setbrg(struct udevice *dev, int baudrate)
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{
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struct zynq_uart_platdata *platdata = dev_get_platdata(dev);
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unsigned long clock;
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int ret;
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struct clk clk;
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ret = clk_get_by_index(dev, 0, &clk);
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if (ret < 0) {
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dev_err(dev, "failed to get clock\n");
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return ret;
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}
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clock = clk_get_rate(&clk);
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if (IS_ERR_VALUE(clock)) {
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dev_err(dev, "failed to get rate\n");
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return clock;
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}
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debug("%s: CLK %ld\n", __func__, clock);
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ret = clk_enable(&clk);
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if (ret && ret != -ENOSYS) {
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dev_err(dev, "failed to enable clock\n");
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return ret;
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}
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_uart_zynq_serial_setbrg(platdata->regs, clock, baudrate);
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return 0;
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}
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static int zynq_serial_probe(struct udevice *dev)
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{
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struct zynq_uart_platdata *platdata = dev_get_platdata(dev);
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/* No need to reinitialize the UART after relocation */
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if (gd->flags & GD_FLG_RELOC)
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return 0;
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_uart_zynq_serial_init(platdata->regs);
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return 0;
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}
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static int zynq_serial_getc(struct udevice *dev)
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{
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struct zynq_uart_platdata *platdata = dev_get_platdata(dev);
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struct uart_zynq *regs = platdata->regs;
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if (readl(®s->channel_sts) & ZYNQ_UART_SR_RXEMPTY)
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return -EAGAIN;
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return readl(®s->tx_rx_fifo);
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}
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static int zynq_serial_putc(struct udevice *dev, const char ch)
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{
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struct zynq_uart_platdata *platdata = dev_get_platdata(dev);
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return _uart_zynq_serial_putc(platdata->regs, ch);
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}
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static int zynq_serial_pending(struct udevice *dev, bool input)
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{
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struct zynq_uart_platdata *platdata = dev_get_platdata(dev);
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struct uart_zynq *regs = platdata->regs;
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if (input)
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return !(readl(®s->channel_sts) & ZYNQ_UART_SR_RXEMPTY);
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else
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return !!(readl(®s->channel_sts) & ZYNQ_UART_SR_TXACTIVE);
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}
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static int zynq_serial_ofdata_to_platdata(struct udevice *dev)
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{
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struct zynq_uart_platdata *platdata = dev_get_platdata(dev);
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platdata->regs = (struct uart_zynq *)dev_read_addr(dev);
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if (IS_ERR(platdata->regs))
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return PTR_ERR(platdata->regs);
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return 0;
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}
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static const struct dm_serial_ops zynq_serial_ops = {
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.putc = zynq_serial_putc,
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.pending = zynq_serial_pending,
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.getc = zynq_serial_getc,
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.setbrg = zynq_serial_setbrg,
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};
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static const struct udevice_id zynq_serial_ids[] = {
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{ .compatible = "xlnx,xuartps" },
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{ .compatible = "cdns,uart-r1p8" },
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{ .compatible = "cdns,uart-r1p12" },
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{ }
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};
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U_BOOT_DRIVER(serial_zynq) = {
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.name = "serial_zynq",
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.id = UCLASS_SERIAL,
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.of_match = zynq_serial_ids,
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.ofdata_to_platdata = zynq_serial_ofdata_to_platdata,
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.platdata_auto_alloc_size = sizeof(struct zynq_uart_platdata),
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.probe = zynq_serial_probe,
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.ops = &zynq_serial_ops,
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};
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#ifdef CONFIG_DEBUG_UART_ZYNQ
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static inline void _debug_uart_init(void)
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{
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struct uart_zynq *regs = (struct uart_zynq *)CONFIG_DEBUG_UART_BASE;
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_uart_zynq_serial_init(regs);
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_uart_zynq_serial_setbrg(regs, CONFIG_DEBUG_UART_CLOCK,
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CONFIG_BAUDRATE);
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}
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static inline void _debug_uart_putc(int ch)
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{
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struct uart_zynq *regs = (struct uart_zynq *)CONFIG_DEBUG_UART_BASE;
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while (_uart_zynq_serial_putc(regs, ch) == -EAGAIN)
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WATCHDOG_RESET();
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}
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DEBUG_UART_FUNCS
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#endif
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