dm: Add a uclass for serial devices

Serial devices support simple byte input/output and a few operations to find
out whether data is available. Add a basic uclass for serial devices to be
used by drivers that are converted to driver model.

Signed-off-by: Simon Glass <sjg@chromium.org>

1 files changed, 213 insertions, 0 deletions

diff --git a/drivers/serial/serial-uclass.c b/drivers/serial/serial-uclass.c
new file mode 100644
index 0000000..d04104e
--- /dev/null
+++ b/drivers/serial/serial-uclass.c
@@ -0,0 +1,213 @@
+/*
+ * Copyright (c) 2014 The Chromium OS Authors.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <fdtdec.h>
+#include <os.h>
+#include <serial.h>
+#include <stdio_dev.h>
+#include <dm/lists.h>
+#include <dm/device-internal.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/* The currently-selected console serial device */
+struct udevice *cur_dev __attribute__ ((section(".data")));
+
+#ifndef CONFIG_SYS_MALLOC_F_LEN
+#error "Serial is required before relocation - define CONFIG_SYS_MALLOC_F_LEN to make this work"
+#endif
+
+static void serial_find_console_or_panic(void)
+{
+	int node;
+
+	/* Check for a chosen console */
+	node = fdtdec_get_chosen_node(gd->fdt_blob, "stdout-path");
+	if (node < 0)
+		node = fdtdec_get_alias_node(gd->fdt_blob, "console");
+	if (!uclass_get_device_by_of_offset(UCLASS_SERIAL, node, &cur_dev))
+		return;
+
+	/*
+	 * If the console is not marked to be bound before relocation, bind
+	 * it anyway.
+	 */
+	if (node > 0 &&
+	    !lists_bind_fdt(gd->dm_root, gd->fdt_blob, node, &cur_dev)) {
+		if (!device_probe(cur_dev))
+			return;
+		cur_dev = NULL;
+	}
+
+	/*
+	 * Failing that, get the device with sequence number 0, or in extremis
+	 * just the first serial device we can find. But we insist on having
+	 * a console (even if it is silent).
+	 */
+	if (uclass_get_device_by_seq(UCLASS_SERIAL, 0, &cur_dev) &&
+	    (uclass_first_device(UCLASS_SERIAL, &cur_dev) || !cur_dev))
+		panic("No serial driver found");
+}
+
+/* Called prior to relocation */
+int serial_init(void)
+{
+	serial_find_console_or_panic();
+	gd->flags |= GD_FLG_SERIAL_READY;
+
+	return 0;
+}
+
+/* Called after relocation */
+void serial_initialize(void)
+{
+	serial_find_console_or_panic();
+}
+
+void serial_putc(char ch)
+{
+	struct dm_serial_ops *ops = serial_get_ops(cur_dev);
+	int err;
+
+	do {
+		err = ops->putc(cur_dev, ch);
+	} while (err == -EAGAIN);
+	if (ch == '\n')
+		serial_putc('\r');
+}
+
+void serial_setbrg(void)
+{
+	struct dm_serial_ops *ops = serial_get_ops(cur_dev);
+
+	if (ops->setbrg)
+		ops->setbrg(cur_dev, gd->baudrate);
+}
+
+void serial_puts(const char *str)
+{
+	while (*str)
+		serial_putc(*str++);
+}
+
+int serial_tstc(void)
+{
+	struct dm_serial_ops *ops = serial_get_ops(cur_dev);
+
+	if (ops->pending)
+		return ops->pending(cur_dev, true);
+
+	return 1;
+}
+
+int serial_getc(void)
+{
+	struct dm_serial_ops *ops = serial_get_ops(cur_dev);
+	int err;
+
+	do {
+		err = ops->getc(cur_dev);
+	} while (err == -EAGAIN);
+
+	return err >= 0 ? err : 0;
+}
+
+void serial_stdio_init(void)
+{
+}
+
+void serial_stub_putc(struct stdio_dev *sdev, const char ch)
+{
+	struct udevice *dev = sdev->priv;
+	struct dm_serial_ops *ops = serial_get_ops(dev);
+
+	ops->putc(dev, ch);
+}
+
+void serial_stub_puts(struct stdio_dev *sdev, const char *str)
+{
+	while (*str)
+		serial_stub_putc(sdev, *str++);
+}
+
+int serial_stub_getc(struct stdio_dev *sdev)
+{
+	struct udevice *dev = sdev->priv;
+	struct dm_serial_ops *ops = serial_get_ops(dev);
+
+	int err;
+
+	do {
+		err = ops->getc(dev);
+	} while (err == -EAGAIN);
+
+	return err >= 0 ? err : 0;
+}
+
+int serial_stub_tstc(struct stdio_dev *sdev)
+{
+	struct udevice *dev = sdev->priv;
+	struct dm_serial_ops *ops = serial_get_ops(dev);
+
+	if (ops->pending)
+		return ops->pending(dev, true);
+
+	return 1;
+}
+
+static int serial_post_probe(struct udevice *dev)
+{
+	struct stdio_dev sdev;
+	struct dm_serial_ops *ops = serial_get_ops(dev);
+	struct serial_dev_priv *upriv = dev->uclass_priv;
+	int ret;
+
+	/* Set the baud rate */
+	if (ops->setbrg) {
+		ret = ops->setbrg(dev, gd->baudrate);
+		if (ret)
+			return ret;
+	}
+
+	if (!(gd->flags & GD_FLG_RELOC))
+		return 0;
+
+	memset(&sdev, '\0', sizeof(sdev));
+
+	strncpy(sdev.name, dev->name, sizeof(sdev.name));
+	sdev.flags = DEV_FLAGS_OUTPUT | DEV_FLAGS_INPUT;
+	sdev.priv = dev;
+	sdev.putc = serial_stub_putc;
+	sdev.puts = serial_stub_puts;
+	sdev.getc = serial_stub_getc;
+	sdev.tstc = serial_stub_tstc;
+	stdio_register_dev(&sdev, &upriv->sdev);
+
+	return 0;
+}
+
+static int serial_pre_remove(struct udevice *dev)
+{
+#ifdef CONFIG_SYS_STDIO_DEREGISTER
+	struct serial_dev_priv *upriv = dev->uclass_priv;
+
+	if (stdio_deregister_dev(upriv->sdev))
+		return -EPERM;
+#endif
+
+	return 0;
+}
+
+UCLASS_DRIVER(serial) = {
+	.id		= UCLASS_SERIAL,
+	.name		= "serial",
+	.post_probe	= serial_post_probe,
+	.pre_remove	= serial_pre_remove,
+	.per_device_auto_alloc_size = sizeof(struct serial_dev_priv),
+};