[PATCH 1/1] serial: earlycon: Add support for big-endian MMIO accesses

From: Noam Camus
Date: Sun May 24 2015 - 23:54:52 EST


From: Noam Camus <noamc@xxxxxxxxxx>

Support command line parameters of the form:
earlycon=<name>,io|mmio|mmio32|mmio32be,<addr>,<options>

This commit seem to be needed even after commit:
serial: 8250: Add support for big-endian MMIO accesses
c627f2ceb692e8a9358b64ac2d139314e7bb0d17

Signed-off-by: Noam Camus <noamc@xxxxxxxxxx>
---
Documentation/kernel-parameters.txt | 9 +++++----
drivers/tty/serial/earlycon.c | 9 ++++++---
drivers/tty/serial/serial_core.c | 7 +++++--
3 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 61ab162..55bb093 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -959,14 +959,15 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
uart[8250],io,<addr>[,options]
uart[8250],mmio,<addr>[,options]
uart[8250],mmio32,<addr>[,options]
+ uart[8250],mmio32be,<addr>[,options]
uart[8250],0x<addr>[,options]
Start an early, polled-mode console on the 8250/16550
UART at the specified I/O port or MMIO address.
MMIO inter-register address stride is either 8-bit
- (mmio) or 32-bit (mmio32).
- If none of [io|mmio|mmio32], <addr> is assumed to be
- equivalent to 'mmio'. 'options' are specified in the
- same format described for "console=ttyS<n>"; if
+ (mmio) or 32-bit (mmio32 or mmio32be).
+ If none of [io|mmio|mmio32|mmio32be], <addr> is assumed
+ to be equivalent to 'mmio'. 'options' are specified
+ in the same format described for "console=ttyS<n>"; if
unspecified, the h/w is not initialized.

pl011,<addr>
diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c
index 5fdc9f3..a840732 100644
--- a/drivers/tty/serial/earlycon.c
+++ b/drivers/tty/serial/earlycon.c
@@ -72,6 +72,7 @@ static int __init parse_options(struct earlycon_device *device, char *options)

switch (port->iotype) {
case UPIO_MEM32:
+ case UPIO_MEM32BE:
port->regshift = 2; /* fall-through */
case UPIO_MEM:
port->mapbase = addr;
@@ -90,9 +91,11 @@ static int __init parse_options(struct earlycon_device *device, char *options)
strlcpy(device->options, options, length);
}

- if (port->iotype == UPIO_MEM || port->iotype == UPIO_MEM32)
+ if (port->iotype == UPIO_MEM || port->iotype == UPIO_MEM32 ||
+ port->iotype == UPIO_MEM32BE)
pr_info("Early serial console at MMIO%s 0x%llx (options '%s')\n",
- (port->iotype == UPIO_MEM32) ? "32" : "",
+ (port->iotype == UPIO_MEM) ? "" :
+ (port->iotype == UPIO_MEM32) ? "32" : "32be",
(unsigned long long)port->mapbase,
device->options);
else
@@ -133,7 +136,7 @@ static int __init register_earlycon(char *buf, const struct earlycon_id *match)
*
* 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>,io|mmio|mmio32|mmio32be,<addr>,<options>
* <name>,0x<addr>,<options>
* <name>,<options>
* <name>
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 0b7bb12..1124090 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -1816,8 +1816,8 @@ uart_get_console(struct uart_port *ports, int nr, struct console *co)
* @options: ptr for <options> field; NULL if not present (out)
*
* Decodes earlycon kernel command line parameters of the form
- * earlycon=<name>,io|mmio|mmio32,<addr>,<options>
- * console=<name>,io|mmio|mmio32,<addr>,<options>
+ * earlycon=<name>,io|mmio|mmio32|mmio32be,<addr>,<options>
+ * console=<name>,io|mmio|mmio32|mmio32be,<addr>,<options>
*
* The optional form
* earlycon=<name>,0x<addr>,<options>
@@ -1835,6 +1835,9 @@ int uart_parse_earlycon(char *p, unsigned char *iotype, unsigned long *addr,
} else if (strncmp(p, "mmio32,", 7) == 0) {
*iotype = UPIO_MEM32;
p += 7;
+ } else if (strncmp(p, "mmio32be,", 9) == 0) {
+ *iotype = UPIO_MEM32BE;
+ p += 9;
} else if (strncmp(p, "io,", 3) == 0) {
*iotype = UPIO_PORT;
p += 3;
--
1.7.1

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