Re: [PATCH v3 3/3] watchdog: sama5d4_wdt: addition of sam9x60 compatible watchdog

From: Guenter Roeck
Date: Tue Nov 12 2019 - 09:01:49 EST

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In reply to: Eugen.Hristev: "[PATCH v3 3/3] watchdog: sama5d4_wdt: addition of sam9x60 compatible watchdog"
Next in thread: Guenter Roeck: "Re: [PATCH v3 1/3] watchdog: sama5d4_wdt: cleanup the bit definitions"
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On 11/11/19 4:13 AM, Eugen.Hristev@xxxxxxxxxxxxx wrote:

From: Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx>

Add support for SAM9X60 WDT into sama5d4_wdt.
This means that this driver gets a flag inside the data struct
that represents the sam9x60 support.
This flag differentiates between the two hardware blocks, and is set
according to the compatible of the driver instantiation.

Signed-off-by: Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx>
---
Changes in v3:
- changed need_irq to bool, instead of a single bit variable.
- the platform data config struct is gone now, changed to a pointer to a bool
to have the sam9x60_support as 'true', pointing to a static bool with true value.
Can have a better solution than this ?
- the specific sam9x60_support flag is assigned at probe time, corresponding
to the flag value in .data

drivers/watchdog/at91sam9_wdt.h | 14 +++++
drivers/watchdog/sama5d4_wdt.c | 120 ++++++++++++++++++++++++++++++----------
2 files changed, 105 insertions(+), 29 deletions(-)

diff --git a/drivers/watchdog/at91sam9_wdt.h b/drivers/watchdog/at91sam9_wdt.h
index 2ca5fc5..2a85135 100644
--- a/drivers/watchdog/at91sam9_wdt.h
+++ b/drivers/watchdog/at91sam9_wdt.h
@@ -20,7 +20,10 @@
#define AT91_WDT_MR 0x04 /* Watchdog Mode Register */
#define AT91_WDT_WDV (0xfff << 0) /* Counter Value */
#define AT91_WDT_SET_WDV(x) ((x) & AT91_WDT_WDV)
+#define AT91_SAM9X60_PERIODRST BIT(4) /* Period Reset */
+#define AT91_SAM9X60_RPTHRST BIT(5) /* Minimum Restart Period */
#define AT91_WDT_WDFIEN BIT(12) /* Fault Interrupt Enable */
+#define AT91_SAM9X60_WDDIS BIT(12) /* Watchdog Disable */
#define AT91_WDT_WDRSTEN BIT(13) /* Reset Processor */
#define AT91_WDT_WDRPROC BIT(14) /* Timer Restart */
#define AT91_WDT_WDDIS BIT(15) /* Watchdog Disable */
@@ -33,4 +36,15 @@
#define AT91_WDT_WDUNF BIT(0) /* Watchdog Underflow */
#define AT91_WDT_WDERR BIT(1) /* Watchdog Error */
+#define AT91_SAM9X60_VR 0x08 /* Watchdog Timer Value Register */
+
+#define AT91_SAM9X60_WLR 0x0c
+#define AT91_SAM9X60_COUNTER (0xfff << 0) /* Watchdog Period Value */
+#define AT91_SAM9X60_SET_COUNTER(x) ((x) & AT91_SAM9X60_COUNTER)
+
+#define AT91_SAM9X60_IER 0x14 /* Interrupt Enable Register */
+#define AT91_SAM9X60_PERINT BIT(0) /* Period Interrupt Enable */
+#define AT91_SAM9X60_IDR 0x18 /* Interrupt Disable Register */
+#define AT91_SAM9X60_ISR 0x1c /* Interrupt Status Register */
+
#endif
diff --git a/drivers/watchdog/sama5d4_wdt.c b/drivers/watchdog/sama5d4_wdt.c
index d193a60..cf53354 100644
--- a/drivers/watchdog/sama5d4_wdt.c
+++ b/drivers/watchdog/sama5d4_wdt.c
@@ -2,7 +2,7 @@
/*
* Driver for Atmel SAMA5D4 Watchdog Timer
*
- * Copyright (C) 2015 Atmel Corporation
+ * Copyright (C) 2015-2019 Microchip Technology Inc. and its subsidiaries
*/
#include <linux/delay.h>
@@ -11,6 +11,7 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
+#include <linux/of_device.h>
#include <linux/of_irq.h>
#include <linux/platform_device.h>
#include <linux/reboot.h>
@@ -26,10 +27,13 @@
#define WDT_SEC2TICKS(s) ((s) ? (((s) << 8) - 1) : 0)
struct sama5d4_wdt {
- struct watchdog_device wdd;
- void __iomem *reg_base;
- u32 mr;
- unsigned long last_ping;
+ struct watchdog_device wdd;

Why add another tab here ? That seems excessive.

+ void __iomem *reg_base;
+ u32 mr;
+ u32 ir;
+ unsigned long last_ping;
+ bool need_irq;
+ bool sam9x60_support;
};
static int wdt_timeout;
@@ -78,7 +82,12 @@ static int sama5d4_wdt_start(struct watchdog_device *wdd)
{
struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd);
- wdt->mr &= ~AT91_WDT_WDDIS;
+ if (wdt->sam9x60_support) {
+ writel_relaxed(wdt->ir, wdt->reg_base + AT91_SAM9X60_IER);
+ wdt->mr &= ~AT91_SAM9X60_WDDIS;
+ } else {
+ wdt->mr &= ~AT91_WDT_WDDIS;
+ }
wdt_write(wdt, AT91_WDT_MR, wdt->mr);
return 0;
@@ -88,7 +97,12 @@ static int sama5d4_wdt_stop(struct watchdog_device *wdd)
{
struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd);
- wdt->mr |= AT91_WDT_WDDIS;
+ if (wdt->sam9x60_support) {
+ writel_relaxed(wdt->ir, wdt->reg_base + AT91_SAM9X60_IDR);
+ wdt->mr |= AT91_SAM9X60_WDDIS;
+ } else {
+ wdt->mr |= AT91_WDT_WDDIS;
+ }
wdt_write(wdt, AT91_WDT_MR, wdt->mr);
return 0;
@@ -109,6 +123,14 @@ static int sama5d4_wdt_set_timeout(struct watchdog_device *wdd,
struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd);
u32 value = WDT_SEC2TICKS(timeout);
+ if (wdt->sam9x60_support) {
+ wdt_write(wdt, AT91_SAM9X60_WLR,
+ AT91_SAM9X60_SET_COUNTER(value));
+
+ wdd->timeout = timeout;
+ return 0;
+ }
+
wdt->mr &= ~AT91_WDT_WDV;
wdt->mr |= AT91_WDT_SET_WDV(value);
@@ -143,8 +165,14 @@ static const struct watchdog_ops sama5d4_wdt_ops = {
static irqreturn_t sama5d4_wdt_irq_handler(int irq, void *dev_id)
{
struct sama5d4_wdt *wdt = platform_get_drvdata(dev_id);
+ u32 reg;
- if (wdt_read(wdt, AT91_WDT_SR)) {
+ if (wdt->sam9x60_support)
+ reg = wdt_read(wdt, AT91_SAM9X60_ISR);
+ else
+ reg = wdt_read(wdt, AT91_WDT_SR);
+
+ if (reg) {
pr_crit("Atmel Watchdog Software Reset\n");
emergency_restart();
pr_crit("Reboot didn't succeed\n");
@@ -157,13 +185,14 @@ static int of_sama5d4_wdt_init(struct device_node *np, struct sama5d4_wdt *wdt)
{
const char *tmp;
- wdt->mr = AT91_WDT_WDDIS;
+ if (wdt->sam9x60_support)
+ wdt->mr = AT91_SAM9X60_WDDIS;
+ else
+ wdt->mr = AT91_WDT_WDDIS;
if (!of_property_read_string(np, "atmel,watchdog-type", &tmp) &&
!strcmp(tmp, "software"))
- wdt->mr |= AT91_WDT_WDFIEN;
- else
- wdt->mr |= AT91_WDT_WDRSTEN;
+ wdt->need_irq = true;
if (of_property_read_bool(np, "atmel,idle-halt"))
wdt->mr |= AT91_WDT_WDIDLEHLT;
@@ -176,21 +205,46 @@ static int of_sama5d4_wdt_init(struct device_node *np, struct sama5d4_wdt *wdt)
static int sama5d4_wdt_init(struct sama5d4_wdt *wdt)
{
- u32 reg;
+ u32 reg, val;
+
+ val = WDT_SEC2TICKS(WDT_DEFAULT_TIMEOUT);
/*
* When booting and resuming, the bootloader may have changed the
* watchdog configuration.
* If the watchdog is already running, we can safely update it.
* Else, we have to disable it properly.
*/
- if (wdt_enabled) {
- wdt_write_nosleep(wdt, AT91_WDT_MR, wdt->mr);
- } else {
+ if (!wdt_enabled) {
reg = wdt_read(wdt, AT91_WDT_MR);
- if (!(reg & AT91_WDT_WDDIS))
+ if (wdt->sam9x60_support && (!(reg & AT91_SAM9X60_WDDIS)))
+ wdt_write_nosleep(wdt, AT91_WDT_MR,
+ reg | AT91_SAM9X60_WDDIS);
+ else if (!wdt->sam9x60_support &&
+ (!(reg & AT91_WDT_WDDIS)))
wdt_write_nosleep(wdt, AT91_WDT_MR,
reg | AT91_WDT_WDDIS);
}
+
+ if (wdt->sam9x60_support) {
+ if (wdt->need_irq)
+ wdt->ir = AT91_SAM9X60_PERINT;
+ else
+ wdt->mr |= AT91_SAM9X60_PERIODRST;
+
+ wdt_write(wdt, AT91_SAM9X60_IER, wdt->ir);
+ wdt_write(wdt, AT91_SAM9X60_WLR, AT91_SAM9X60_SET_COUNTER(val));
+ } else {
+ wdt->mr |= AT91_WDT_SET_WDD(WDT_SEC2TICKS(MAX_WDT_TIMEOUT));
+ wdt->mr |= AT91_WDT_SET_WDV(val);
+
+ if (wdt->need_irq)
+ wdt->mr |= AT91_WDT_WDFIEN;
+ else
+ wdt->mr |= AT91_WDT_WDRSTEN;
+ }
+
+ wdt_write_nosleep(wdt, AT91_WDT_MR, wdt->mr);
+
return 0;
}
@@ -200,14 +254,16 @@ static int sama5d4_wdt_probe(struct platform_device *pdev)
struct watchdog_device *wdd;
struct sama5d4_wdt *wdt;
void __iomem *regs;
+ const void *data;
u32 irq = 0;
- u32 timeout;
int ret;
wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
if (!wdt)
return -ENOMEM;
+ data = of_device_get_match_data(&pdev->dev);
+
wdd = &wdt->wdd;
wdd->timeout = WDT_DEFAULT_TIMEOUT;
wdd->info = &sama5d4_wdt_info;
@@ -215,6 +271,7 @@ static int sama5d4_wdt_probe(struct platform_device *pdev)
wdd->min_timeout = MIN_WDT_TIMEOUT;
wdd->max_timeout = MAX_WDT_TIMEOUT;
wdt->last_ping = jiffies;
+ wdt->sam9x60_support = data ? *(bool *)data : false;

wdt->sam9x60_support = of_device_is_compatible(dev, "microchip,sam9x60-wdt");

should do.

watchdog_set_drvdata(wdd, wdt);
@@ -224,15 +281,17 @@ static int sama5d4_wdt_probe(struct platform_device *pdev)
wdt->reg_base = regs;
- irq = irq_of_parse_and_map(dev->of_node, 0);
- if (!irq)
- dev_warn(dev, "failed to get IRQ from DT\n");
-
ret = of_sama5d4_wdt_init(dev->of_node, wdt);
if (ret)
return ret;
- if ((wdt->mr & AT91_WDT_WDFIEN) && irq) {
+ irq = irq_of_parse_and_map(dev->of_node, 0);
+ if (!irq) {

Why call irq_of_parse_and_map() in the first place if need_irq is false ?
Doesn't this generate an unnecessary warning if need_irq is false and
if there is no interrupt node ?

+ dev_warn(dev, "failed to get IRQ from DT\n");
+ wdt->need_irq = false;
+ }
+
+ if (wdt->need_irq) {
ret = devm_request_irq(dev, irq, sama5d4_wdt_irq_handler,
IRQF_SHARED | IRQF_IRQPOLL |
IRQF_NO_SUSPEND, pdev->name, pdev);
@@ -244,11 +303,6 @@ static int sama5d4_wdt_probe(struct platform_device *pdev)
watchdog_init_timeout(wdd, wdt_timeout, dev);
- timeout = WDT_SEC2TICKS(wdd->timeout);
-
- wdt->mr |= AT91_WDT_SET_WDD(WDT_SEC2TICKS(MAX_WDT_TIMEOUT));
- wdt->mr |= AT91_WDT_SET_WDV(timeout);
-
ret = sama5d4_wdt_init(wdt);
if (ret)
return ret;
@@ -268,8 +322,16 @@ static int sama5d4_wdt_probe(struct platform_device *pdev)
return 0;
}
+static bool sam9x60_config = true;
+
static const struct of_device_id sama5d4_wdt_of_match[] = {
- { .compatible = "atmel,sama5d4-wdt", },
+ {
+ .compatible = "atmel,sama5d4-wdt",
+ },
+ {
+ .compatible = "microchip,sam9x60-wdt",
+ .data = &sam9x60_config,
+ },
{ }
};
MODULE_DEVICE_TABLE(of, sama5d4_wdt_of_match);

Next message: Daniel Vetter: "Re: [PATCH 1/4] drm/msm: fix memleak on release"
Previous message: Andrew Lunn: "Re: [PATCH 2/2] ARM: dts: ls1021a-tsn: Use interrupts for the SGMII PHYs"
In reply to: Eugen.Hristev: "[PATCH v3 3/3] watchdog: sama5d4_wdt: addition of sam9x60 compatible watchdog"
Next in thread: Guenter Roeck: "Re: [PATCH v3 1/3] watchdog: sama5d4_wdt: cleanup the bit definitions"
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