--- /dev/null
+/*
+ * Copyright (C) 2014 Linaro Ltd.
+ * Author: Rob Herring <robh@kernel.org>
+ *
+ * Based on 8250 earlycon:
+ * (c) Copyright 2004 Hewlett-Packard Development Company, L.P.
+ * Bjorn Helgaas <bjorn.helgaas@hp.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.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/console.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/serial_core.h>
+#include <linux/sizes.h>
+#include <linux/mod_devicetable.h>
+
+#ifdef CONFIG_FIX_EARLYCON_MEM
+#include <asm/fixmap.h>
+#endif
+
+#include <asm/serial.h>
+
+static struct console early_con = {
+ .name = "uart", /* 8250 console switch requires this name */
+ .flags = CON_PRINTBUFFER | CON_BOOT,
+ .index = -1,
+};
+
+static struct earlycon_device early_console_dev = {
+ .con = &early_con,
+};
+
+extern struct earlycon_id __earlycon_table[];
+static const struct earlycon_id __earlycon_table_sentinel
+ __used __section(__earlycon_table_end);
+
+static const struct of_device_id __earlycon_of_table_sentinel
+ __used __section(__earlycon_of_table_end);
+
+static void __iomem * __init earlycon_map(unsigned long paddr, size_t size)
+{
+ void __iomem *base;
+#ifdef CONFIG_FIX_EARLYCON_MEM
+ set_fixmap_io(FIX_EARLYCON_MEM_BASE, paddr & PAGE_MASK);
+ base = (void __iomem *)__fix_to_virt(FIX_EARLYCON_MEM_BASE);
+ base += paddr & ~PAGE_MASK;
+#else
+ base = ioremap(paddr, size);
+#endif
+ if (!base)
+ pr_err("%s: Couldn't map 0x%llx\n", __func__,
+ (unsigned long long)paddr);
+
+ return base;
+}
+
+static int __init parse_options(struct earlycon_device *device, char *options)
+{
+ struct uart_port *port = &device->port;
+ int length;
+ unsigned long addr;
+
+ if (uart_parse_earlycon(options, &port->iotype, &addr, &options))
+ return -EINVAL;
+
+ switch (port->iotype) {
+ case UPIO_MEM32:
+ port->regshift = 2; /* fall-through */
+ case UPIO_MEM:
+ port->mapbase = addr;
+ break;
+ case UPIO_PORT:
+ port->iobase = addr;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (options) {
+ device->baud = simple_strtoul(options, NULL, 0);
+ length = min(strcspn(options, " ") + 1,
+ (size_t)(sizeof(device->options)));
+ strlcpy(device->options, options, length);
+ }
+
+ if (port->iotype == UPIO_MEM || port->iotype == UPIO_MEM32)
+ pr_info("Early serial console at MMIO%s 0x%llx (options '%s')\n",
+ (port->iotype == UPIO_MEM32) ? "32" : "",
+ (unsigned long long)port->mapbase,
+ device->options);
+ else
+ pr_info("Early serial console at I/O port 0x%lx (options '%s')\n",
+ port->iobase,
+ device->options);
+
+ return 0;
+}
+
+static int __init register_earlycon(char *buf, const struct earlycon_id *match)
+{
+ int err;
+ struct uart_port *port = &early_console_dev.port;
+
+ /* On parsing error, pass the options buf to the setup function */
+ if (buf && !parse_options(&early_console_dev, buf))
+ buf = NULL;
+
+ port->uartclk = BASE_BAUD * 16;
+ if (port->mapbase)
+ port->membase = earlycon_map(port->mapbase, 64);
+
+ early_console_dev.con->data = &early_console_dev;
+ err = match->setup(&early_console_dev, buf);
+ if (err < 0)
+ return err;
+ if (!early_console_dev.con->write)
+ return -ENODEV;
+
+ register_console(early_console_dev.con);
+ return 0;
+}
+
+/**
+ * setup_earlycon - match and register earlycon console
+ * @buf: earlycon param string
+ *
+ * Registers the earlycon console matching the earlycon specified
+ * in the param string @buf. Acceptable param strings are of the form
+ * <name>,io|mmio|mmio32,<addr>,<options>
+ * <name>,0x<addr>,<options>
+ * <name>,<options>
+ * <name>
+ *
+ * Only for the third form does the earlycon setup() method receive the
+ * <options> string in the 'options' parameter; all other forms set
+ * the parameter to NULL.
+ *
+ * Returns 0 if an attempt to register the earlycon was made,
+ * otherwise negative error code
+ */
+int __init setup_earlycon(char *buf)
+{
+ const struct earlycon_id *match;
+
+ if (!buf || !buf[0])
+ return -EINVAL;
+
+ if (early_con.flags & CON_ENABLED)
+ return -EALREADY;
+
+ for (match = __earlycon_table; match->name[0]; match++) {
+ size_t len = strlen(match->name);
+
+ if (strncmp(buf, match->name, len))
+ continue;
+
+ if (buf[len]) {
+ if (buf[len] != ',')
+ continue;
+ buf += len + 1;
+ } else
+ buf = NULL;
+
+ return register_earlycon(buf, match);
+ }
+
+ return -ENOENT;
+}
+
+/* early_param wrapper for setup_earlycon() */
+static int __init param_setup_earlycon(char *buf)
+{
+ int err;
+
+ /*
+ * Just 'earlycon' is a valid param for devicetree earlycons;
+ * don't generate a warning from parse_early_params() in that case
+ */
+ if (!buf || !buf[0])
+ return 0;
+
+ err = setup_earlycon(buf);
+ if (err == -ENOENT || err == -EALREADY)
+ return 0;
+ return err;
+}
+early_param("earlycon", param_setup_earlycon);
+
+int __init of_setup_earlycon(unsigned long addr,
+ int (*setup)(struct earlycon_device *, const char *))
+{
+ int err;
+ struct uart_port *port = &early_console_dev.port;
+
+ port->iotype = UPIO_MEM;
+ port->mapbase = addr;
+ port->uartclk = BASE_BAUD * 16;
+ port->membase = earlycon_map(addr, SZ_4K);
+
+ early_console_dev.con->data = &early_console_dev;
+ err = setup(&early_console_dev, NULL);
+ if (err < 0)
+ return err;
+ if (!early_console_dev.con->write)
+ return -ENODEV;
+
+
+ register_console(early_console_dev.con);
+ return 0;
+}
Code Review / kvmfornfv.git / blobdiff