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Subject[PATCH AUTOSEL 4.18 22/45] watchdog: lantiq: update register names to better match spec
Date
From: Hauke Mehrtens <hauke@hauke-m.de>

[ Upstream commit 1f59f8aff98f200af7a6882184add7b85f5da741 ]

Some of the names of the bits were confusing to me.
Now the bits share the same prefix as the register they are set on.

The LTQ_WDT_CR_PWL register (bits 26:25) is the pre warning limit and it
does not turn anything on. It has 4 possible divers 1/2, 1/4, 1/8 and
1/16, this drivers only uses 1/16.
The LTQ_WDT_CR_CLKDIV register bits(25:24) is only configuring a clock
divers and do not turn any thing on too, all possible values are valid
dividers.
Using the LTQ_WDT_SR prefix is also wrong these bits are used in the
LTQ_WDT_CR registers, SR is the status register which is read only.

This uses GENMASK where it is a mask and it uses shifts when a value is
written to some bits.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/watchdog/lantiq_wdt.c | 36 ++++++++++++++++++-----------------
1 file changed, 19 insertions(+), 17 deletions(-)

diff --git a/drivers/watchdog/lantiq_wdt.c b/drivers/watchdog/lantiq_wdt.c
index 7f43cefa0eae..a086005fbaac 100644
--- a/drivers/watchdog/lantiq_wdt.c
+++ b/drivers/watchdog/lantiq_wdt.c
@@ -13,6 +13,7 @@
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
+#include <linux/bitops.h>
#include <linux/watchdog.h>
#include <linux/of_platform.h>
#include <linux/uaccess.h>
@@ -40,18 +41,19 @@
* essentially the following two magic passwords need to be written to allow
* IO access to the WDT core
*/
-#define LTQ_WDT_PW1 0x00BE0000
-#define LTQ_WDT_PW2 0x00DC0000
+#define LTQ_WDT_CR_PW1 0x00BE0000
+#define LTQ_WDT_CR_PW2 0x00DC0000
+
+#define LTQ_WDT_CR 0x0 /* watchdog control register */
+#define LTQ_WDT_CR_GEN BIT(31) /* enable bit */
+/* Pre-warning limit set to 1/16 of max WDT period */
+#define LTQ_WDT_CR_PWL (0x3 << 26)
+/* set clock divider to 0x40000 */
+#define LTQ_WDT_CR_CLKDIV (0x3 << 24)
+#define LTQ_WDT_CR_PW_MASK GENMASK(23, 16) /* Password field */
+#define LTQ_WDT_CR_MAX_TIMEOUT ((1 << 16) - 1) /* The reload field is 16 bit */

-#define LTQ_WDT_CR 0x0 /* watchdog control register */
-#define LTQ_WDT_SR 0x8 /* watchdog status register */
-
-#define LTQ_WDT_SR_EN (0x1 << 31) /* enable bit */
-#define LTQ_WDT_SR_PWD (0x3 << 26) /* turn on power */
-#define LTQ_WDT_SR_CLKDIV (0x3 << 24) /* turn on clock and set */
- /* divider to 0x40000 */
#define LTQ_WDT_DIVIDER 0x40000
-#define LTQ_MAX_TIMEOUT ((1 << 16) - 1) /* the reload field is 16 bit */

static bool nowayout = WATCHDOG_NOWAYOUT;

@@ -68,26 +70,26 @@ ltq_wdt_enable(void)
{
unsigned long int timeout = ltq_wdt_timeout *
(ltq_io_region_clk_rate / LTQ_WDT_DIVIDER) + 0x1000;
- if (timeout > LTQ_MAX_TIMEOUT)
- timeout = LTQ_MAX_TIMEOUT;
+ if (timeout > LTQ_WDT_CR_MAX_TIMEOUT)
+ timeout = LTQ_WDT_CR_MAX_TIMEOUT;

/* write the first password magic */
- ltq_w32(LTQ_WDT_PW1, ltq_wdt_membase + LTQ_WDT_CR);
+ ltq_w32(LTQ_WDT_CR_PW1, ltq_wdt_membase + LTQ_WDT_CR);
/* write the second magic plus the configuration and new timeout */
- ltq_w32(LTQ_WDT_SR_EN | LTQ_WDT_SR_PWD | LTQ_WDT_SR_CLKDIV |
- LTQ_WDT_PW2 | timeout, ltq_wdt_membase + LTQ_WDT_CR);
+ ltq_w32(LTQ_WDT_CR_GEN | LTQ_WDT_CR_PWL | LTQ_WDT_CR_CLKDIV |
+ LTQ_WDT_CR_PW2 | timeout, ltq_wdt_membase + LTQ_WDT_CR);
}

static void
ltq_wdt_disable(void)
{
/* write the first password magic */
- ltq_w32(LTQ_WDT_PW1, ltq_wdt_membase + LTQ_WDT_CR);
+ ltq_w32(LTQ_WDT_CR_PW1, ltq_wdt_membase + LTQ_WDT_CR);
/*
* write the second password magic with no config
* this turns the watchdog off
*/
- ltq_w32(LTQ_WDT_PW2, ltq_wdt_membase + LTQ_WDT_CR);
+ ltq_w32(LTQ_WDT_CR_PW2, ltq_wdt_membase + LTQ_WDT_CR);
}

static ssize_t
--
2.17.1
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