Commit 088da2a1 authored by Peter Hurley's avatar Peter Hurley Committed by Greg Kroah-Hartman
Browse files

of: earlycon: Initialize port fields from DT properties 



Read the optional "reg-offset", "reg-shift", "reg-io-width" and endianness
properties and initialize the respective struct uart_port field if found.

NB: These bindings are common to several drivers and the values merely
indicate the default value; the registering earlycon setup() method can
simply override the values if required.

Acked-by: default avatarRob Herring <robh@kernel.org>
Signed-off-by: default avatarPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 4d118c9a

drivers/of/fdt.c

+1 −1
Original line number Diff line number Diff line
@@ -839,7 +839,7 @@ static int __init early_init_dt_scan_chosen_serial(void) 
		if (addr == OF_BAD_ADDR)

			return -ENXIO;



		of_setup_earlycon(addr, match, options);

		of_setup_earlycon(addr, match, offset, options);

		return 0;

	}

	return -ENODEV;

drivers/tty/serial/earlycon.c

+31 −0
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ 
#include <linux/io.h>

#include <linux/serial_core.h>

#include <linux/sizes.h>

#include <linux/of_fdt.h>



#ifdef CONFIG_FIX_EARLYCON_MEM

#include <asm/fixmap.h>
@@ -219,10 +220,13 @@ early_param("earlycon", param_setup_earlycon); 


int __init of_setup_earlycon(unsigned long addr,

			     const struct earlycon_id *match,

			     unsigned long node,

			     const char *options)

{

	int err;

	struct uart_port *port = &early_console_dev.port;

	const __be32 *val;

	bool big_endian;



	spin_lock_init(&port->lock);

	port->iotype = UPIO_MEM;
@@ -230,6 +234,33 @@ int __init of_setup_earlycon(unsigned long addr, 
	port->uartclk = BASE_BAUD * 16;

	port->membase = earlycon_map(addr, SZ_4K);



	val = of_get_flat_dt_prop(node, "reg-offset", NULL);

	if (val)

		port->mapbase += be32_to_cpu(*val);

	val = of_get_flat_dt_prop(node, "reg-shift", NULL);

	if (val)

		port->regshift = be32_to_cpu(*val);

	big_endian = of_get_flat_dt_prop(node, "big-endian", NULL) != NULL ||

		(IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&

		 of_get_flat_dt_prop(node, "native-endian", NULL) != NULL);

	val = of_get_flat_dt_prop(node, "reg-io-width", NULL);

	if (val) {

		switch (be32_to_cpu(*val)) {

		case 1:

			port->iotype = UPIO_MEM;

			break;

		case 2:

			port->iotype = UPIO_MEM16;

			break;

		case 4:

			port->iotype = (big_endian) ? UPIO_MEM32BE : UPIO_MEM32;

			break;

		default:

			pr_warn("[%s] unsupported reg-io-width\n", match->name);

			return -EINVAL;

		}

	}



	if (options) {

		strlcpy(early_console_dev.options, options,

			sizeof(early_console_dev.options));

include/linux/serial_core.h

+1 −0
Original line number Diff line number Diff line
@@ -360,6 +360,7 @@ extern const struct earlycon_id __earlycon_table_end[]; 


extern int setup_earlycon(char *buf);

extern int of_setup_earlycon(unsigned long addr, const struct earlycon_id *match,

			     unsigned long node,

			     const char *options);



struct uart_port *uart_get_console(struct uart_port *ports, int nr,

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