u-boot/common/stdio.c
Simon Glass d8441ea27e dm: stdio: Allow lazy probing of video devices
At present all video devices are probed on start-up. It would be better to
probe a device only when it is needed. This can happen if it is referenced
in the stdout environment variable, for example.

Add support for this by searching for a suitable device when needed, probing
it, and finding the stdio device it creates.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2016-10-11 11:55:33 +08:00

414 lines
9.6 KiB
C

/*
* Copyright (C) 2009 Sergey Kubushyn <ksi@koi8.net>
*
* Changes for multibus/multiadapter I2C support.
*
* (C) Copyright 2000
* Paolo Scaffardi, AIRVENT SAM s.p.a - RIMINI(ITALY), arsenio@tin.it
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <config.h>
#include <common.h>
#include <dm.h>
#include <errno.h>
#include <stdarg.h>
#include <malloc.h>
#include <stdio_dev.h>
#include <serial.h>
#ifdef CONFIG_LOGBUFFER
#include <logbuff.h>
#endif
#if defined(CONFIG_HARD_I2C) || defined(CONFIG_SYS_I2C)
#include <i2c.h>
#endif
#include <dm/device-internal.h>
DECLARE_GLOBAL_DATA_PTR;
static struct stdio_dev devs;
struct stdio_dev *stdio_devices[] = { NULL, NULL, NULL };
char *stdio_names[MAX_FILES] = { "stdin", "stdout", "stderr" };
#if defined(CONFIG_SPLASH_SCREEN) && !defined(CONFIG_SYS_DEVICE_NULLDEV)
#define CONFIG_SYS_DEVICE_NULLDEV 1
#endif
#ifdef CONFIG_SYS_STDIO_DEREGISTER
#define CONFIG_SYS_DEVICE_NULLDEV 1
#endif
#ifdef CONFIG_SYS_DEVICE_NULLDEV
static void nulldev_putc(struct stdio_dev *dev, const char c)
{
/* nulldev is empty! */
}
static void nulldev_puts(struct stdio_dev *dev, const char *s)
{
/* nulldev is empty! */
}
static int nulldev_input(struct stdio_dev *dev)
{
/* nulldev is empty! */
return 0;
}
#endif
static void stdio_serial_putc(struct stdio_dev *dev, const char c)
{
serial_putc(c);
}
static void stdio_serial_puts(struct stdio_dev *dev, const char *s)
{
serial_puts(s);
}
static int stdio_serial_getc(struct stdio_dev *dev)
{
return serial_getc();
}
static int stdio_serial_tstc(struct stdio_dev *dev)
{
return serial_tstc();
}
/**************************************************************************
* SYSTEM DRIVERS
**************************************************************************
*/
static void drv_system_init (void)
{
struct stdio_dev dev;
memset (&dev, 0, sizeof (dev));
strcpy (dev.name, "serial");
dev.flags = DEV_FLAGS_OUTPUT | DEV_FLAGS_INPUT;
dev.putc = stdio_serial_putc;
dev.puts = stdio_serial_puts;
dev.getc = stdio_serial_getc;
dev.tstc = stdio_serial_tstc;
stdio_register (&dev);
#ifdef CONFIG_SYS_DEVICE_NULLDEV
memset (&dev, 0, sizeof (dev));
strcpy (dev.name, "nulldev");
dev.flags = DEV_FLAGS_OUTPUT | DEV_FLAGS_INPUT;
dev.putc = nulldev_putc;
dev.puts = nulldev_puts;
dev.getc = nulldev_input;
dev.tstc = nulldev_input;
stdio_register (&dev);
#endif
}
/**************************************************************************
* DEVICES
**************************************************************************
*/
struct list_head* stdio_get_list(void)
{
return &(devs.list);
}
#ifdef CONFIG_DM_VIDEO
/**
* stdio_probe_device() - Find a device which provides the given stdio device
*
* This looks for a device of the given uclass which provides a particular
* stdio device. It is currently really only useful for UCLASS_VIDEO.
*
* Ultimately we want to be able to probe a device by its stdio name. At
* present devices register in their probe function (for video devices this
* is done in vidconsole_post_probe()) and we don't know what name they will
* use until they do so.
* TODO(sjg@chromium.org): We should be able to determine the name before
* probing, and probe the required device.
*
* @name: stdio device name (e.g. "vidconsole")
* id: Uclass ID of device to look for (e.g. UCLASS_VIDEO)
* @sdevp: Returns stdout device, if found, else NULL
* @return 0 if found, -ENOENT if no device found with that name, other -ve
* on other error
*/
static int stdio_probe_device(const char *name, enum uclass_id id,
struct stdio_dev **sdevp)
{
struct stdio_dev *sdev;
struct udevice *dev;
int seq, ret;
*sdevp = NULL;
seq = trailing_strtoln(name, NULL);
if (seq == -1)
ret = uclass_first_device_err(id, &dev);
else
ret = uclass_get_device_by_seq(id, seq, &dev);
if (ret) {
debug("No %s device for seq %d (%s)\n", uclass_get_name(id),
seq, name);
return ret;
}
/* The device should be be the last one registered */
sdev = list_empty(&devs.list) ? NULL :
list_last_entry(&devs.list, struct stdio_dev, list);
if (!sdev || strcmp(sdev->name, name)) {
debug("Device '%s' did not register with stdio as '%s'\n",
dev->name, name);
return -ENOENT;
}
*sdevp = sdev;
return 0;
}
#endif
struct stdio_dev* stdio_get_by_name(const char *name)
{
struct list_head *pos;
struct stdio_dev *sdev;
if(!name)
return NULL;
list_for_each(pos, &(devs.list)) {
sdev = list_entry(pos, struct stdio_dev, list);
if (strcmp(sdev->name, name) == 0)
return sdev;
}
#ifdef CONFIG_DM_VIDEO
/*
* We did not find a suitable stdio device. If there is a video
* driver with a name starting with 'vidconsole', we can try probing
* that in the hope that it will produce the required stdio device.
*
* This function is sometimes called with the entire value of
* 'stdout', which may include a list of devices separate by commas.
* Obviously this is not going to work, so we ignore that case. The
* call path in that case is console_init_r() -> search_device() ->
* stdio_get_by_name().
*/
if (!strncmp(name, "vidconsole", 10) && !strchr(name, ',') &&
!stdio_probe_device(name, UCLASS_VIDEO, &sdev))
return sdev;
#endif
return NULL;
}
struct stdio_dev* stdio_clone(struct stdio_dev *dev)
{
struct stdio_dev *_dev;
if(!dev)
return NULL;
_dev = calloc(1, sizeof(struct stdio_dev));
if(!_dev)
return NULL;
memcpy(_dev, dev, sizeof(struct stdio_dev));
return _dev;
}
int stdio_register_dev(struct stdio_dev *dev, struct stdio_dev **devp)
{
struct stdio_dev *_dev;
_dev = stdio_clone(dev);
if(!_dev)
return -ENODEV;
list_add_tail(&(_dev->list), &(devs.list));
if (devp)
*devp = _dev;
return 0;
}
int stdio_register(struct stdio_dev *dev)
{
return stdio_register_dev(dev, NULL);
}
/* deregister the device "devname".
* returns 0 if success, -1 if device is assigned and 1 if devname not found
*/
#ifdef CONFIG_SYS_STDIO_DEREGISTER
int stdio_deregister_dev(struct stdio_dev *dev, int force)
{
int l;
struct list_head *pos;
char temp_names[3][16];
/* get stdio devices (ListRemoveItem changes the dev list) */
for (l=0 ; l< MAX_FILES; l++) {
if (stdio_devices[l] == dev) {
if (force) {
strcpy(temp_names[l], "nulldev");
continue;
}
/* Device is assigned -> report error */
return -1;
}
memcpy (&temp_names[l][0],
stdio_devices[l]->name,
sizeof(temp_names[l]));
}
list_del(&(dev->list));
free(dev);
/* reassign Device list */
list_for_each(pos, &(devs.list)) {
dev = list_entry(pos, struct stdio_dev, list);
for (l=0 ; l< MAX_FILES; l++) {
if(strcmp(dev->name, temp_names[l]) == 0)
stdio_devices[l] = dev;
}
}
return 0;
}
int stdio_deregister(const char *devname, int force)
{
struct stdio_dev *dev;
dev = stdio_get_by_name(devname);
if (!dev) /* device not found */
return -ENODEV;
return stdio_deregister_dev(dev, force);
}
#endif /* CONFIG_SYS_STDIO_DEREGISTER */
int stdio_init_tables(void)
{
#if defined(CONFIG_NEEDS_MANUAL_RELOC)
/* already relocated for current ARM implementation */
ulong relocation_offset = gd->reloc_off;
int i;
/* relocate device name pointers */
for (i = 0; i < (sizeof (stdio_names) / sizeof (char *)); ++i) {
stdio_names[i] = (char *) (((ulong) stdio_names[i]) +
relocation_offset);
}
#endif /* CONFIG_NEEDS_MANUAL_RELOC */
/* Initialize the list */
INIT_LIST_HEAD(&(devs.list));
return 0;
}
int stdio_add_devices(void)
{
#ifdef CONFIG_DM_KEYBOARD
struct udevice *dev;
struct uclass *uc;
int ret;
/*
* For now we probe all the devices here. At some point this should be
* done only when the devices are required - e.g. we have a list of
* input devices to start up in the stdin environment variable. That
* work probably makes more sense when stdio itself is converted to
* driver model.
*
* TODO(sjg@chromium.org): Convert changing uclass_first_device() etc.
* to return the device even on error. Then we could use that here.
*/
ret = uclass_get(UCLASS_KEYBOARD, &uc);
if (ret)
return ret;
/* Don't report errors to the caller - assume that they are non-fatal */
uclass_foreach_dev(dev, uc) {
ret = device_probe(dev);
if (ret)
printf("Failed to probe keyboard '%s'\n", dev->name);
}
#endif
#ifdef CONFIG_SYS_I2C
i2c_init_all();
#else
#if defined(CONFIG_HARD_I2C)
i2c_init (CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
#endif
#endif
#ifdef CONFIG_DM_VIDEO
/*
* If the console setting is not in environment variables then
* console_init_r() will not be calling iomux_doenv() (which calls
* search_device()). So we will not dynamically add devices by
* calling stdio_probe_device().
*
* So just probe all video devices now so that whichever one is
* required will be available.
*/
#ifndef CONFIG_SYS_CONSOLE_IS_IN_ENV
struct udevice *vdev;
# ifndef CONFIG_DM_KEYBOARD
int ret;
# endif
for (ret = uclass_first_device(UCLASS_VIDEO, &vdev);
vdev;
ret = uclass_next_device(&vdev))
;
if (ret)
printf("%s: Video device failed (ret=%d)\n", __func__, ret);
#endif /* !CONFIG_SYS_CONSOLE_IS_IN_ENV */
#else
# if defined(CONFIG_LCD)
drv_lcd_init ();
# endif
# if defined(CONFIG_VIDEO) || defined(CONFIG_CFB_CONSOLE)
drv_video_init ();
# endif
#endif /* CONFIG_DM_VIDEO */
#if defined(CONFIG_KEYBOARD) && !defined(CONFIG_DM_KEYBOARD)
drv_keyboard_init ();
#endif
#ifdef CONFIG_LOGBUFFER
drv_logbuff_init ();
#endif
drv_system_init ();
serial_stdio_init ();
#ifdef CONFIG_USB_TTY
drv_usbtty_init ();
#endif
#ifdef CONFIG_NETCONSOLE
drv_nc_init ();
#endif
#ifdef CONFIG_JTAG_CONSOLE
drv_jtag_console_init ();
#endif
#ifdef CONFIG_CBMEM_CONSOLE
cbmemc_init();
#endif
return 0;
}
int stdio_init(void)
{
stdio_init_tables();
stdio_add_devices();
return 0;
}