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>
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),
+};