tty: amba-pl011: probe ZTE device from AMBA bus with a pseudo-ID

There is no Peripheral Identification Registers on ZTE PL011 device, so
although the driver amba-pl011 is ready to work for ZTE device, the
device cannot be probed by the driver at all.

With arm,primecell-periphid DT bindings (bindings/arm/primecell.txt) in
place, it should be the cleanest the way to use a pseudo-ID to probe the
device from AMBA bus.  We create an unofficial vendor number
AMBA_VENDOR_LINUX, which will practically never become an official
vendor ID, and takes Configuration, Revision number, and Part number as
input to compose a pseudo-ID for ZTE device.

Also, since we start using vendor_zte to probe ZTE device, the
__maybe_unused for vendor_zte is removed.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 6 insertions, 1 deletions

diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 055fe27e364f..0b78b04e895e 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -209,7 +209,7 @@ static unsigned int get_fifosize_zte(struct amba_device *dev)
 	return 16;
 }
 
-static struct vendor_data vendor_zte __maybe_unused = {
+static struct vendor_data vendor_zte = {
 	.reg_offset		= pl011_zte_offsets,
 	.access_32b		= true,
 	.ifls			= UART011_IFLS_RX4_8|UART011_IFLS_TX4_8,
@@ -2652,6 +2652,11 @@ static struct amba_id pl011_ids[] = {
 		.mask	= 0x00ffffff,
 		.data	= &vendor_st,
 	},
+	{
+		.id	= AMBA_LINUX_ID(0x00, 0x1, 0xffe),
+		.mask	= 0x00ffffff,
+		.data	= &vendor_zte,
+	},
 	{ 0, 0 },
 };