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Commit 2426fbc7 authored by Shawn Guo's avatar Shawn Guo Committed by Greg Kroah-Hartman
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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: default avatarRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: default avatarShawn Guo <shawn.guo@linaro.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 9c267ddb

drivers/tty/serial/amba-pl011.c

+6 −1
Original line number Diff line number Diff line
@@ -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 },

};

include/linux/amba/bus.h

+6 −0
Original line number Diff line number Diff line
@@ -53,8 +53,14 @@ enum amba_vendor { 
	AMBA_VENDOR_ST = 0x80,

	AMBA_VENDOR_QCOM = 0x51,

	AMBA_VENDOR_LSI = 0xb6,

	AMBA_VENDOR_LINUX = 0xfe,	/* This value is not official */

};



/* This is used to generate pseudo-ID for AMBA device */

#define AMBA_LINUX_ID(conf, rev, part) \

	(((conf) & 0xff) << 24 | ((rev) & 0xf) << 20 | \

	AMBA_VENDOR_LINUX << 12 | ((part) & 0xfff))



extern struct bus_type amba_bustype;



#define to_amba_device(d)	container_of(d, struct amba_device, dev)