u-boot/drivers/serial/serial_arc.c
Bin Meng 4687919684 serial: Remove DM_FLAG_PRE_RELOC flag in various drivers
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>
2018-11-14 09:16:28 -08:00

157 lines
3.5 KiB
C

/*
* Copyright (C) 2013 Synopsys, Inc. (www.synopsys.com)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#include <common.h>
#include <dm.h>
#include <serial.h>
DECLARE_GLOBAL_DATA_PTR;
struct arc_serial_regs {
unsigned int id0;
unsigned int id1;
unsigned int id2;
unsigned int id3;
unsigned int data;
unsigned int status;
unsigned int baudl;
unsigned int baudh;
};
struct arc_serial_platdata {
struct arc_serial_regs *reg;
unsigned int uartclk;
};
/* Bit definitions of STATUS register */
#define UART_RXEMPTY (1 << 5)
#define UART_OVERFLOW_ERR (1 << 1)
#define UART_TXEMPTY (1 << 7)
static int arc_serial_setbrg(struct udevice *dev, int baudrate)
{
struct arc_serial_platdata *plat = dev->platdata;
struct arc_serial_regs *const regs = plat->reg;
int arc_console_baud = gd->cpu_clk / (baudrate * 4) - 1;
writeb(arc_console_baud & 0xff, &regs->baudl);
writeb((arc_console_baud & 0xff00) >> 8, &regs->baudh);
return 0;
}
static int arc_serial_putc(struct udevice *dev, const char c)
{
struct arc_serial_platdata *plat = dev->platdata;
struct arc_serial_regs *const regs = plat->reg;
while (!(readb(&regs->status) & UART_TXEMPTY))
;
writeb(c, &regs->data);
return 0;
}
static int arc_serial_tstc(struct arc_serial_regs *const regs)
{
return !(readb(&regs->status) & UART_RXEMPTY);
}
static int arc_serial_pending(struct udevice *dev, bool input)
{
struct arc_serial_platdata *plat = dev->platdata;
struct arc_serial_regs *const regs = plat->reg;
uint32_t status = readb(&regs->status);
if (input)
return status & UART_RXEMPTY ? 0 : 1;
else
return status & UART_TXEMPTY ? 0 : 1;
}
static int arc_serial_getc(struct udevice *dev)
{
struct arc_serial_platdata *plat = dev->platdata;
struct arc_serial_regs *const regs = plat->reg;
while (!arc_serial_tstc(regs))
;
/* Check for overflow errors */
if (readb(&regs->status) & UART_OVERFLOW_ERR)
return 0;
return readb(&regs->data) & 0xFF;
}
static int arc_serial_probe(struct udevice *dev)
{
return 0;
}
static const struct dm_serial_ops arc_serial_ops = {
.putc = arc_serial_putc,
.pending = arc_serial_pending,
.getc = arc_serial_getc,
.setbrg = arc_serial_setbrg,
};
static const struct udevice_id arc_serial_ids[] = {
{ .compatible = "snps,arc-uart" },
{ }
};
static int arc_serial_ofdata_to_platdata(struct udevice *dev)
{
struct arc_serial_platdata *plat = dev_get_platdata(dev);
DECLARE_GLOBAL_DATA_PTR;
plat->reg = (struct arc_serial_regs *)devfdt_get_addr(dev);
plat->uartclk = fdtdec_get_int(gd->fdt_blob, dev_of_offset(dev),
"clock-frequency", 0);
return 0;
}
U_BOOT_DRIVER(serial_arc) = {
.name = "serial_arc",
.id = UCLASS_SERIAL,
.of_match = arc_serial_ids,
.ofdata_to_platdata = arc_serial_ofdata_to_platdata,
.probe = arc_serial_probe,
.ops = &arc_serial_ops,
};
#ifdef CONFIG_DEBUG_ARC_SERIAL
#include <debug_uart.h>
static inline void _debug_uart_init(void)
{
struct arc_serial_regs *regs = (struct arc_serial_regs *)CONFIG_DEBUG_UART_BASE;
int arc_console_baud = CONFIG_DEBUG_UART_CLOCK / (CONFIG_BAUDRATE * 4) - 1;
writeb(arc_console_baud & 0xff, &regs->baudl);
writeb((arc_console_baud & 0xff00) >> 8, &regs->baudh);
}
static inline void _debug_uart_putc(int c)
{
struct arc_serial_regs *regs = (struct arc_serial_regs *)CONFIG_DEBUG_UART_BASE;
while (!(readb(&regs->status) & UART_TXEMPTY))
;
writeb(c, &regs->data);
}
DEBUG_UART_FUNCS
#endif