[PATCH] tty: amba-pl011: Use 32-bit accesses for SBSA UART

From: Christopher Covington <cov@codeaurora.org>
To: Russell King <linux@arm.linux.org.uk>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jiri Slaby <jslaby@suse.com>,
	linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Timur Tabi <timur@codeaurora.org>, Jon Masters <jcm@redhat.com>,
	Mark Langsdorf <mlangsdo@redhat.com>,
	Andre Przywara <andre.przywara@arm.com>,
	Dave Martin <dave.martin@linaro.org>,
	Aleksey Makarov <aleksey.makarov@linaro.org>,
	Christopher Covington <cov@codeaurora.org>
Subject: [PATCH] tty: amba-pl011: Use 32-bit accesses for SBSA UART
Date: Fri, 11 Mar 2016 01:35:53 -0500	[thread overview]
Message-ID: <1457678154-2272-1-git-send-email-cov@codeaurora.org> (raw)
In-Reply-To: <1457415800-8799-1-git-send-email-cov@codeaurora.org>

Version 2 of the Server Base System Architecture (SBSAv2) describes the
Generic UART registers as 32 bits wide. At least one implementation, found
on the Qualcomm Technologies QDF2432, only supports 32 bit accesses.
SBSAv3, which describes supported access sizes in greater detail,
explicitly requires support for both 16 and 32 bit accesses to all
registers (and 8 bit accesses to some but not all). Therefore, for broad
compatibility, simply use 32 bit accessors for the SBSA UART.

Tested-by: Mark Langsdorf <mlangsdo@redhat.com>
Signed-off-by: Christopher Covington <cov@codeaurora.org>
---
Changes new in v2:
* Fixed from address
* Elaborated on forward (SBSAv3) compatibility in commit message
* Included Mark Langsdorf's Tested-by, which now covers:
    QDF2432
    Seattle
    X-Gene 1
---
 drivers/tty/serial/amba-pl011.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index c0da0cc..ffb5eb8 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -121,6 +121,7 @@ static struct vendor_data vendor_arm = {
 
 static struct vendor_data vendor_sbsa = {
 	.reg_offset		= pl011_std_offsets,
+	.access_32b		= true,
 	.oversampling		= false,
 	.dma_threshold		= false,
 	.cts_event_workaround	= false,
-- 
Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project
