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watchdog: sbsa: use 32-bit read for WCV

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According to SBSA spec v3.1 section 5.3:
  All registers are 32 bits in size and should be accessed using
  32-bit reads and writes. If an access size other than 32 bits
  is used then the results are IMPLEMENTATION DEFINED.
  [...]
  The Generic Watchdog is little-endian

The current code uses readq to read the watchdog compare register
which does a 64-bit access. This fails on ThunderX2 which does not
implement 64-bit access to this register.

Fix this by using lo_hi_readq() that does two 32-bit reads.

Signed-off-by: Jayachandran C <jnair@caviumnetworks.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
This commit is contained in:
Jayachandran C 2018-02-28 02:52:20 -08:00 committed by Wim Van Sebroeck
parent 7bd3e7b743
commit 93ac3deb7c
1 changed files with 2 additions and 1 deletions
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3
drivers/watchdog/sbsa_gwdt.c
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@ -50,6 +50,7 @@
*/
#include <linux/io.h>
#include <linux/io-64-nonatomic-lo-hi.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
@ -159,7 +160,7 @@ static unsigned int sbsa_gwdt_get_timeleft(struct watchdog_device *wdd)
!(readl(gwdt->control_base + SBSA_GWDT_WCS) & SBSA_GWDT_WCS_WS0))
timeleft += readl(gwdt->control_base + SBSA_GWDT_WOR);
timeleft += readq(gwdt->control_base + SBSA_GWDT_WCV) -
timeleft += lo_hi_readq(gwdt->control_base + SBSA_GWDT_WCV) -
arch_counter_get_cntvct();
do_div(timeleft, gwdt->clk);