u-boot/drivers/serial/mcfuart.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2004-2007 Freescale Semiconductor, Inc.
* TsiChung Liew, Tsi-Chung.Liew@freescale.com.
*
* Modified to add device model (DM) support
* (C) Copyright 2015 Angelo Dureghello <angelo@sysam.it>
*
* Modified to add DM and fdt support, removed non DM code
* (C) Copyright 2018 Angelo Dureghello <angelo@sysam.it>
*/
/*
* Minimal serial functions needed to use one of the uart ports
* as serial console interface.
*/
#include <common.h>
#include <dm.h>
#include <dm/platform_data/serial_coldfire.h>
#include <serial.h>
#include <linux/compiler.h>
#include <asm/immap.h>
#include <asm/uart.h>
DECLARE_GLOBAL_DATA_PTR;
extern void uart_port_conf(int port);
static int mcf_serial_init_common(uart_t *uart, int port_idx, int baudrate)
{
u32 counter;
uart_port_conf(port_idx);
/* write to SICR: SIM2 = uart mode,dcd does not affect rx */
writeb(UART_UCR_RESET_RX, &uart->ucr);
writeb(UART_UCR_RESET_TX, &uart->ucr);
writeb(UART_UCR_RESET_ERROR, &uart->ucr);
writeb(UART_UCR_RESET_MR, &uart->ucr);
__asm__("nop");
writeb(0, &uart->uimr);
/* write to CSR: RX/TX baud rate from timers */
writeb(UART_UCSR_RCS_SYS_CLK | UART_UCSR_TCS_SYS_CLK, &uart->ucsr);
writeb(UART_UMR_BC_8 | UART_UMR_PM_NONE, &uart->umr);
writeb(UART_UMR_SB_STOP_BITS_1, &uart->umr);
/* Setting up BaudRate */
counter = (u32) ((gd->bus_clk / 32) + (baudrate / 2));
counter = counter / baudrate;
/* write to CTUR: divide counter upper byte */
writeb((u8)((counter & 0xff00) >> 8), &uart->ubg1);
/* write to CTLR: divide counter lower byte */
writeb((u8)(counter & 0x00ff), &uart->ubg2);
writeb(UART_UCR_RX_ENABLED | UART_UCR_TX_ENABLED, &uart->ucr);
return (0);
}
static void mcf_serial_setbrg_common(uart_t *uart, int baudrate)
{
u32 counter;
/* Setting up BaudRate */
counter = (u32) ((gd->bus_clk / 32) + (baudrate / 2));
counter = counter / baudrate;
/* write to CTUR: divide counter upper byte */
writeb(((counter & 0xff00) >> 8), &uart->ubg1);
/* write to CTLR: divide counter lower byte */
writeb((counter & 0x00ff), &uart->ubg2);
writeb(UART_UCR_RESET_RX, &uart->ucr);
writeb(UART_UCR_RESET_TX, &uart->ucr);
writeb(UART_UCR_RX_ENABLED | UART_UCR_TX_ENABLED, &uart->ucr);
}
static int coldfire_serial_probe(struct udevice *dev)
{
struct coldfire_serial_platdata *plat = dev->platdata;
return mcf_serial_init_common((uart_t *)plat->base,
plat->port, plat->baudrate);
}
static int coldfire_serial_putc(struct udevice *dev, const char ch)
{
struct coldfire_serial_platdata *plat = dev->platdata;
uart_t *uart = (uart_t *)plat->base;
/* Wait for last character to go. */
if (!(readb(&uart->usr) & UART_USR_TXRDY))
return -EAGAIN;
writeb(ch, &uart->utb);
return 0;
}
static int coldfire_serial_getc(struct udevice *dev)
{
struct coldfire_serial_platdata *plat = dev->platdata;
uart_t *uart = (uart_t *)(plat->base);
/* Wait for a character to arrive. */
if (!(readb(&uart->usr) & UART_USR_RXRDY))
return -EAGAIN;
return readb(&uart->urb);
}
int coldfire_serial_setbrg(struct udevice *dev, int baudrate)
{
struct coldfire_serial_platdata *plat = dev->platdata;
uart_t *uart = (uart_t *)(plat->base);
mcf_serial_setbrg_common(uart, baudrate);
return 0;
}
static int coldfire_serial_pending(struct udevice *dev, bool input)
{
struct coldfire_serial_platdata *plat = dev->platdata;
uart_t *uart = (uart_t *)(plat->base);
if (input)
return readb(&uart->usr) & UART_USR_RXRDY ? 1 : 0;
else
return readb(&uart->usr) & UART_USR_TXRDY ? 0 : 1;
return 0;
}
static int coldfire_ofdata_to_platdata(struct udevice *dev)
{
struct coldfire_serial_platdata *plat = dev_get_platdata(dev);
fdt_addr_t addr_base;
addr_base = devfdt_get_addr(dev);
if (addr_base == FDT_ADDR_T_NONE)
return -ENODEV;
plat->base = (uint32_t)addr_base;
plat->port = dev->seq;
plat->baudrate = gd->baudrate;
return 0;
}
static const struct dm_serial_ops coldfire_serial_ops = {
.putc = coldfire_serial_putc,
.pending = coldfire_serial_pending,
.getc = coldfire_serial_getc,
.setbrg = coldfire_serial_setbrg,
};
static const struct udevice_id coldfire_serial_ids[] = {
{ .compatible = "fsl,mcf-uart" },
{ }
};
U_BOOT_DRIVER(serial_coldfire) = {
.name = "serial_coldfire",
.id = UCLASS_SERIAL,
.of_match = coldfire_serial_ids,
.ofdata_to_platdata = coldfire_ofdata_to_platdata,
.platdata_auto_alloc_size = sizeof(struct coldfire_serial_platdata),
.probe = coldfire_serial_probe,
.ops = &coldfire_serial_ops,
.flags = DM_FLAG_PRE_RELOC,
};