1 files changed, 105 insertions, 181 deletions

diff --git a/drivers/tty/serial/8250/8250_early.c b/drivers/tty/serial/8250/8250_early.c
index 721904f8efa9..dc0371857ecb 100644
--- a/drivers/tty/serial/8250/8250_early.c
+++ b/drivers/tty/serial/8250/8250_early.c
@@ -1,13 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Early serial console for 8250/16550 devices
  *
  * (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.
- *
  * Based on the 8250.c serial driver, Copyright (C) 2001 Russell King,
  * and on early_printk.c by Andi Kleen.
  *
@@ -29,259 +26,186 @@
 #include <linux/tty.h>
 #include <linux/init.h>
 #include <linux/console.h>
-#include <linux/serial_core.h>
+#include <linux/of.h>
 #include <linux/serial_reg.h>
 #include <linux/serial.h>
 #include <linux/serial_8250.h>
 #include <asm/io.h>
 #include <asm/serial.h>
-#ifdef CONFIG_FIX_EARLYCON_MEM
-#include <asm/pgtable.h>
-#include <asm/fixmap.h>
-#endif
-
-struct early_serial8250_device {
-	struct uart_port port;
-	char options[16];		/* e.g., 115200n8 */
-	unsigned int baud;
-};
-
-static struct early_serial8250_device early_device;
 
-unsigned int __weak __init serial8250_early_in(struct uart_port *port, int offset)
+static unsigned int serial8250_early_in(struct uart_port *port, int offset)
 {
+	offset <<= port->regshift;
+
 	switch (port->iotype) {
 	case UPIO_MEM:
 		return readb(port->membase + offset);
+	case UPIO_MEM16:
+		return readw(port->membase + offset);
 	case UPIO_MEM32:
-		return readl(port->membase + (offset << 2));
+		return readl(port->membase + offset);
+	case UPIO_MEM32BE:
+		return ioread32be(port->membase + offset);
+#ifdef CONFIG_HAS_IOPORT
 	case UPIO_PORT:
 		return inb(port->iobase + offset);
+#endif
 	default:
 		return 0;
 	}
 }
 
-void __weak __init serial8250_early_out(struct uart_port *port, int offset, int value)
+static void serial8250_early_out(struct uart_port *port, int offset, int value)
 {
+	offset <<= port->regshift;
+
 	switch (port->iotype) {
 	case UPIO_MEM:
 		writeb(value, port->membase + offset);
 		break;
+	case UPIO_MEM16:
+		writew(value, port->membase + offset);
+		break;
 	case UPIO_MEM32:
-		writel(value, port->membase + (offset << 2));
+		writel(value, port->membase + offset);
 		break;
+	case UPIO_MEM32BE:
+		iowrite32be(value, port->membase + offset);
+		break;
+#ifdef CONFIG_HAS_IOPORT
 	case UPIO_PORT:
 		outb(value, port->iobase + offset);
 		break;
+#endif
+	default:
+		break;
 	}
 }
 
-#define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
-
-static void __init wait_for_xmitr(struct uart_port *port)
+static void serial_putc(struct uart_port *port, unsigned char c)
 {
 	unsigned int status;
 
+	serial8250_early_out(port, UART_TX, c);
+
 	for (;;) {
 		status = serial8250_early_in(port, UART_LSR);
-		if ((status & BOTH_EMPTY) == BOTH_EMPTY)
-			return;
+		if (uart_lsr_tx_empty(status))
+			break;
 		cpu_relax();
 	}
 }
 
-static void __init serial_putc(struct uart_port *port, int c)
-{
-	wait_for_xmitr(port);
-	serial8250_early_out(port, UART_TX, c);
-}
-
-static void __init early_serial8250_write(struct console *console,
+static void early_serial8250_write(struct console *console,
 					const char *s, unsigned int count)
 {
-	struct uart_port *port = &early_device.port;
-	unsigned int ier;
-
-	/* Save the IER and disable interrupts */
-	ier = serial8250_early_in(port, UART_IER);
-	serial8250_early_out(port, UART_IER, 0);
+	struct earlycon_device *device = console->data;
+	struct uart_port *port = &device->port;
 
 	uart_console_write(port, s, count, serial_putc);
-
-	/* Wait for transmitter to become empty and restore the IER */
-	wait_for_xmitr(port);
-	serial8250_early_out(port, UART_IER, ier);
 }
 
-static unsigned int __init probe_baud(struct uart_port *port)
+#ifdef CONFIG_CONSOLE_POLL
+static int early_serial8250_read(struct console *console,
+				 char *s, unsigned int count)
 {
-	unsigned char lcr, dll, dlm;
-	unsigned int quot;
+	struct earlycon_device *device = console->data;
+	struct uart_port *port = &device->port;
+	unsigned int status;
+	int num_read = 0;
 
-	lcr = serial8250_early_in(port, UART_LCR);
-	serial8250_early_out(port, UART_LCR, lcr | UART_LCR_DLAB);
-	dll = serial8250_early_in(port, UART_DLL);
-	dlm = serial8250_early_in(port, UART_DLM);
-	serial8250_early_out(port, UART_LCR, lcr);
+	while (num_read < count) {
+		status = serial8250_early_in(port, UART_LSR);
+		if (!(status & UART_LSR_DR))
+			break;
+		s[num_read++] = serial8250_early_in(port, UART_RX);
+	}
 
-	quot = (dlm << 8) | dll;
-	return (port->uartclk / 16) / quot;
+	return num_read;
 }
+#else
+#define early_serial8250_read NULL
+#endif
 
-static void __init init_port(struct early_serial8250_device *device)
+static void __init init_port(struct earlycon_device *device)
 {
 	struct uart_port *port = &device->port;
 	unsigned int divisor;
 	unsigned char c;
+	unsigned int ier;
 
-	serial8250_early_out(port, UART_LCR, 0x3);	/* 8n1 */
-	serial8250_early_out(port, UART_IER, 0);	/* no interrupt */
+	serial8250_early_out(port, UART_LCR, UART_LCR_WLEN8);		/* 8n1 */
+	ier = serial8250_early_in(port, UART_IER);
+	serial8250_early_out(port, UART_IER, ier & UART_IER_UUE); /* no interrupt */
 	serial8250_early_out(port, UART_FCR, 0);	/* no fifo */
-	serial8250_early_out(port, UART_MCR, 0x3);	/* DTR + RTS */
-
-	divisor = DIV_ROUND_CLOSEST(port->uartclk, 16 * device->baud);
-	c = serial8250_early_in(port, UART_LCR);
-	serial8250_early_out(port, UART_LCR, c | UART_LCR_DLAB);
-	serial8250_early_out(port, UART_DLL, divisor & 0xff);
-	serial8250_early_out(port, UART_DLM, (divisor >> 8) & 0xff);
-	serial8250_early_out(port, UART_LCR, c & ~UART_LCR_DLAB);
+	serial8250_early_out(port, UART_MCR, UART_MCR_DTR | UART_MCR_RTS);
+
+	if (port->uartclk) {
+		divisor = DIV_ROUND_CLOSEST(port->uartclk, 16 * device->baud);
+		c = serial8250_early_in(port, UART_LCR);
+		serial8250_early_out(port, UART_LCR, c | UART_LCR_DLAB);
+		serial8250_early_out(port, UART_DLL, divisor & 0xff);
+		serial8250_early_out(port, UART_DLM, (divisor >> 8) & 0xff);
+		serial8250_early_out(port, UART_LCR, c & ~UART_LCR_DLAB);
+	}
 }
 
-static int __init parse_options(struct early_serial8250_device *device,
-								char *options)
+int __init early_serial8250_setup(struct earlycon_device *device,
+					 const char *options)
 {
-	struct uart_port *port = &device->port;
-	int mmio, mmio32, length;
-
-	if (!options)
+	if (!(device->port.membase || device->port.iobase))
 		return -ENODEV;
 
-	port->uartclk = BASE_BAUD * 16;
+	if (!device->baud) {
+		struct uart_port *port = &device->port;
+		unsigned int ier;
 
-	mmio = !strncmp(options, "mmio,", 5);
-	mmio32 = !strncmp(options, "mmio32,", 7);
-	if (mmio || mmio32) {
-		port->iotype = (mmio ? UPIO_MEM : UPIO_MEM32);
-		port->mapbase = simple_strtoul(options + (mmio ? 5 : 7),
-					       &options, 0);
-		if (mmio32)
-			port->regshift = 2;
-#ifdef CONFIG_FIX_EARLYCON_MEM
-		set_fixmap_nocache(FIX_EARLYCON_MEM_BASE,
-					port->mapbase & PAGE_MASK);
-		port->membase =
-			(void __iomem *)__fix_to_virt(FIX_EARLYCON_MEM_BASE);
-		port->membase += port->mapbase & ~PAGE_MASK;
-#else
-		port->membase = ioremap_nocache(port->mapbase, 64);
-		if (!port->membase) {
-			printk(KERN_ERR "%s: Couldn't ioremap 0x%llx\n",
-				__func__,
-			       (unsigned long long) port->mapbase);
-			return -ENOMEM;
-		}
-#endif
-	} else if (!strncmp(options, "io,", 3)) {
-		port->iotype = UPIO_PORT;
-		port->iobase = simple_strtoul(options + 3, &options, 0);
-		mmio = 0;
+		/* assume the device was initialized, only mask interrupts */
+		ier = serial8250_early_in(port, UART_IER);
+		serial8250_early_out(port, UART_IER, ier & UART_IER_UUE);
 	} else
-		return -EINVAL;
-
-	options = strchr(options, ',');
-	if (options) {
-		options++;
-		device->baud = simple_strtoul(options, NULL, 0);
-		length = min(strcspn(options, " "), sizeof(device->options));
-		strlcpy(device->options, options, length);
-	} else {
-		device->baud = probe_baud(port);
-		snprintf(device->options, sizeof(device->options), "%u",
-			device->baud);
-	}
-
-	if (mmio || mmio32)
-		printk(KERN_INFO
-		       "Early serial console at MMIO%s 0x%llx (options '%s')\n",
-			mmio32 ? "32" : "",
-			(unsigned long long)port->mapbase,
-			device->options);
-	else
-		printk(KERN_INFO
-		      "Early serial console at I/O port 0x%lx (options '%s')\n",
-			port->iobase,
-			device->options);
+		init_port(device);
 
+	device->con->write = early_serial8250_write;
+	device->con->read = early_serial8250_read;
 	return 0;
 }
-
-static struct console early_serial8250_console __initdata = {
-	.name	= "uart",
-	.write	= early_serial8250_write,
-	.flags	= CON_PRINTBUFFER | CON_BOOT,
-	.index	= -1,
-};
-
-static int __init early_serial8250_setup(char *options)
+EARLYCON_DECLARE(uart8250, early_serial8250_setup);
+EARLYCON_DECLARE(uart, early_serial8250_setup);
+OF_EARLYCON_DECLARE(ns16550, "ns16550", early_serial8250_setup);
+OF_EARLYCON_DECLARE(ns16550a, "ns16550a", early_serial8250_setup);
+OF_EARLYCON_DECLARE(uart, "nvidia,tegra20-uart", early_serial8250_setup);
+OF_EARLYCON_DECLARE(uart, "snps,dw-apb-uart", early_serial8250_setup);
+
+static int __init early_serial8250_rs2_setup(struct earlycon_device *device,
+					     const char *options)
 {
-	struct early_serial8250_device *device = &early_device;
-	int err;
-
-	if (device->port.membase || device->port.iobase)
-		return 0;
-
-	err = parse_options(device, options);
-	if (err < 0)
-		return err;
+	device->port.regshift = 2;
 
-	init_port(device);
-	return 0;
+	return early_serial8250_setup(device, options);
 }
+OF_EARLYCON_DECLARE(uart, "intel,xscale-uart", early_serial8250_rs2_setup);
+OF_EARLYCON_DECLARE(uart, "mrvl,mmp-uart", early_serial8250_rs2_setup);
+OF_EARLYCON_DECLARE(uart, "mrvl,pxa-uart", early_serial8250_rs2_setup);
 
-int __init setup_early_serial8250_console(char *cmdline)
-{
-	char *options;
-	int err;
-
-	options = strstr(cmdline, "uart8250,");
-	if (!options) {
-		options = strstr(cmdline, "uart,");
-		if (!options)
-			return 0;
-	}
-
-	options = strchr(cmdline, ',') + 1;
-	err = early_serial8250_setup(options);
-	if (err < 0)
-		return err;
-
-	register_console(&early_serial8250_console);
+#ifdef CONFIG_SERIAL_8250_OMAP
 
-	return 0;
-}
-
-int serial8250_find_port_for_earlycon(void)
+static int __init early_omap8250_setup(struct earlycon_device *device,
+				       const char *options)
 {
-	struct early_serial8250_device *device = &early_device;
 	struct uart_port *port = &device->port;
-	int line;
-	int ret;
-
-	if (!device->port.membase && !device->port.iobase)
-		return -ENODEV;
 
-	line = serial8250_find_port(port);
-	if (line < 0)
+	if (!(device->port.membase || device->port.iobase))
 		return -ENODEV;
 
-	ret = update_console_cmdline("uart", 8250,
-			     "ttyS", line, device->options);
-	if (ret < 0)
-		ret = update_console_cmdline("uart", 0,
-				     "ttyS", line, device->options);
-
-	return ret;
+	port->regshift = 2;
+	device->con->write = early_serial8250_write;
+	return 0;
 }
 
-early_param("earlycon", setup_early_serial8250_console);
+OF_EARLYCON_DECLARE(omap8250, "ti,omap2-uart", early_omap8250_setup);
+OF_EARLYCON_DECLARE(omap8250, "ti,omap3-uart", early_omap8250_setup);
+OF_EARLYCON_DECLARE(omap8250, "ti,omap4-uart", early_omap8250_setup);
+OF_EARLYCON_DECLARE(omap8250, "ti,am654-uart", early_omap8250_setup);
+
+#endif