This patch series adds watchod support for abracon RTC chips which
include basic watchdog functionality.
Changes in v2:
* split out priv structure into a separate patch
* remove new Kconfig option
* fix CONFIG_WATCHDOG dependency
* fix WDT interrupt message
Jeremy Gebben (2):
rtc: abx80x: use a 'priv' struct for client data
rtc: abx80x: add basic watchdog support
drivers/rtc/rtc-abx80x.c | 159 ++++++++++++++++++++++++++++++++++++---
1 file changed, 147 insertions(+), 12 deletions(-)
--
2.17.1
The abx804 and abx805 chips have support for a simple watchdog
function that can trigger an external reset.
Signed-off-by: Jeremy Gebben <[email protected]>
---
drivers/rtc/rtc-abx80x.c | 132 +++++++++++++++++++++++++++++++++++++--
1 file changed, 128 insertions(+), 4 deletions(-)
diff --git a/drivers/rtc/rtc-abx80x.c b/drivers/rtc/rtc-abx80x.c
index 9d49054a0a4a..e1ec4cce093a 100644
--- a/drivers/rtc/rtc-abx80x.c
+++ b/drivers/rtc/rtc-abx80x.c
@@ -17,6 +17,7 @@
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/rtc.h>
+#include <linux/watchdog.h>
#define ABX8XX_REG_HTH 0x00
#define ABX8XX_REG_SC 0x01
@@ -37,6 +38,7 @@
#define ABX8XX_REG_STATUS 0x0f
#define ABX8XX_STATUS_AF BIT(2)
+#define ABX8XX_STATUS_WDT BIT(6)
#define ABX8XX_REG_CTRL1 0x10
#define ABX8XX_CTRL_WRITE BIT(0)
@@ -61,6 +63,14 @@
#define ABX8XX_OSS_OF BIT(1)
#define ABX8XX_OSS_OMODE BIT(4)
+#define ABX8XX_REG_WDT 0x1b
+#define ABX8XX_WDT_WDS BIT(7)
+#define ABX8XX_WDT_BMB_MASK 0x7c
+#define ABX8XX_WDT_BMB_SHIFT 2
+#define ABX8XX_WDT_MAX_TIME (ABX8XX_WDT_BMB_MASK >> ABX8XX_WDT_BMB_SHIFT)
+#define ABX8XX_WDT_WRB_MASK 0x03
+#define ABX8XX_WDT_WRB_1HZ 0x02
+
#define ABX8XX_REG_CFG_KEY 0x1f
#define ABX8XX_CFG_KEY_OSC 0xa1
#define ABX8XX_CFG_KEY_MISC 0x9d
@@ -80,23 +90,25 @@ enum abx80x_chip {AB0801, AB0803, AB0804, AB0805,
struct abx80x_cap {
u16 pn;
bool has_tc;
+ bool has_wdog;
};
static struct abx80x_cap abx80x_caps[] = {
[AB0801] = {.pn = 0x0801},
[AB0803] = {.pn = 0x0803},
- [AB0804] = {.pn = 0x0804, .has_tc = true},
- [AB0805] = {.pn = 0x0805, .has_tc = true},
+ [AB0804] = {.pn = 0x0804, .has_tc = true, .has_wdog = true},
+ [AB0805] = {.pn = 0x0805, .has_tc = true, .has_wdog = true},
[AB1801] = {.pn = 0x1801},
[AB1803] = {.pn = 0x1803},
- [AB1804] = {.pn = 0x1804, .has_tc = true},
- [AB1805] = {.pn = 0x1805, .has_tc = true},
+ [AB1804] = {.pn = 0x1804, .has_tc = true, .has_wdog = true},
+ [AB1805] = {.pn = 0x1805, .has_tc = true, .has_wdog = true},
[ABX80X] = {.pn = 0}
};
struct abx80x_priv {
struct rtc_device *rtc;
struct i2c_client *client;
+ struct watchdog_device wdog;
};
static int abx80x_is_rc_mode(struct i2c_client *client)
@@ -234,6 +246,13 @@ static irqreturn_t abx80x_handle_irq(int irq, void *dev_id)
if (status & ABX8XX_STATUS_AF)
rtc_update_irq(rtc, 1, RTC_AF | RTC_IRQF);
+ /*
+ * It is unclear if we'll get an interrupt before the external
+ * reset kicks in.
+ */
+ if (status & ABX8XX_STATUS_WDT)
+ dev_alert(&client->dev, "watchdog timeout interrupt.\n");
+
i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS, 0);
return IRQ_HANDLED;
@@ -535,6 +554,105 @@ static void rtc_calib_remove_sysfs_group(void *_dev)
sysfs_remove_group(&dev->kobj, &rtc_calib_attr_group);
}
+#ifdef CONFIG_WATCHDOG
+
+static inline u8 timeout_bits(unsigned int timeout)
+{
+ return ((timeout << ABX8XX_WDT_BMB_SHIFT) & ABX8XX_WDT_BMB_MASK) |
+ ABX8XX_WDT_WRB_1HZ;
+}
+
+static int __abx80x_wdog_set_timeout(struct watchdog_device *wdog,
+ unsigned int timeout)
+{
+ struct abx80x_priv *priv = watchdog_get_drvdata(wdog);
+ u8 val = ABX8XX_WDT_WDS | timeout_bits(timeout);
+
+ /*
+ * Writing any timeout to the WDT register resets the watchdog timer.
+ * Writing 0 disables it.
+ */
+ return i2c_smbus_write_byte_data(priv->client, ABX8XX_REG_WDT, val);
+}
+
+static int abx80x_wdog_set_timeout(struct watchdog_device *wdog,
+ unsigned int new_timeout)
+{
+ int err = __abx80x_wdog_set_timeout(wdog, new_timeout);
+
+ if (err)
+ return err;
+
+ wdog->timeout = new_timeout;
+ return 0;
+}
+
+static int abx80x_wdog_ping(struct watchdog_device *wdog)
+{
+ return __abx80x_wdog_set_timeout(wdog, wdog->timeout);
+}
+
+static int abx80x_wdog_start(struct watchdog_device *wdog)
+{
+ int err = __abx80x_wdog_set_timeout(wdog, wdog->timeout);
+
+ if (err)
+ return err;
+
+ set_bit(WDOG_HW_RUNNING, &wdog->status);
+ return 0;
+}
+
+static int abx80x_wdog_stop(struct watchdog_device *wdog)
+{
+ int err = __abx80x_wdog_set_timeout(wdog, 0);
+
+ if (err)
+ return err;
+
+ clear_bit(WDOG_HW_RUNNING, &wdog->status);
+ return 0;
+}
+
+static const struct watchdog_info abx80x_wdog_info = {
+ .identity = "abx80x watchdog",
+ .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
+};
+
+static const struct watchdog_ops abx80x_wdog_ops = {
+ .owner = THIS_MODULE,
+ .start = abx80x_wdog_start,
+ .stop = abx80x_wdog_stop,
+ .ping = abx80x_wdog_ping,
+ .set_timeout = abx80x_wdog_set_timeout,
+};
+
+static int abx80x_setup_watchdog(struct abx80x_priv *priv)
+{
+ int err;
+
+ priv->wdog.ops = &abx80x_wdog_ops;
+ priv->wdog.info = &abx80x_wdog_info;
+ priv->wdog.min_timeout = 1;
+ priv->wdog.max_timeout = ABX8XX_WDT_MAX_TIME;
+
+ err = devm_watchdog_register_device(&priv->client->dev,
+ &priv->wdog);
+ if (err)
+ return err;
+
+ watchdog_set_drvdata(&priv->wdog, priv);
+ watchdog_init_timeout(&priv->wdog, ABX8XX_WDT_MAX_TIME,
+ &priv->client->dev);
+ return 0;
+}
+#else
+static int abx80x_setup_watchdog(struct abx80x_priv *priv)
+{
+ return 0;
+}
+#endif
+
static int abx80x_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
@@ -629,6 +747,12 @@ static int abx80x_probe(struct i2c_client *client,
i2c_set_clientdata(client, priv);
+ if (abx80x_caps[part].has_wdog) {
+ err = abx80x_setup_watchdog(priv);
+ if (err)
+ return err;
+ }
+
if (client->irq > 0) {
dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
--
2.17.1
This will allow additional data to be tracked, for future
improvements.
Signed-off-by: Jeremy Gebben <[email protected]>
---
drivers/rtc/rtc-abx80x.c | 27 +++++++++++++++++++--------
1 file changed, 19 insertions(+), 8 deletions(-)
diff --git a/drivers/rtc/rtc-abx80x.c b/drivers/rtc/rtc-abx80x.c
index 2cefa67a1132..9d49054a0a4a 100644
--- a/drivers/rtc/rtc-abx80x.c
+++ b/drivers/rtc/rtc-abx80x.c
@@ -94,6 +94,11 @@ static struct abx80x_cap abx80x_caps[] = {
[ABX80X] = {.pn = 0}
};
+struct abx80x_priv {
+ struct rtc_device *rtc;
+ struct i2c_client *client;
+};
+
static int abx80x_is_rc_mode(struct i2c_client *client)
{
int flags = 0;
@@ -218,7 +223,8 @@ static int abx80x_rtc_set_time(struct device *dev, struct rtc_time *tm)
static irqreturn_t abx80x_handle_irq(int irq, void *dev_id)
{
struct i2c_client *client = dev_id;
- struct rtc_device *rtc = i2c_get_clientdata(client);
+ struct abx80x_priv *priv = i2c_get_clientdata(client);
+ struct rtc_device *rtc = priv->rtc;
int status;
status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
@@ -533,7 +539,7 @@ static int abx80x_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct device_node *np = client->dev.of_node;
- struct rtc_device *rtc;
+ struct abx80x_priv *priv;
int i, data, err, trickle_cfg = -EINVAL;
char buf[7];
unsigned int part = id->driver_data;
@@ -610,13 +616,18 @@ static int abx80x_probe(struct i2c_client *client,
if (err)
return err;
- rtc = devm_rtc_allocate_device(&client->dev);
- if (IS_ERR(rtc))
- return PTR_ERR(rtc);
+ priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
+ if (priv == NULL)
+ return -ENOMEM;
+
+ priv->rtc = devm_rtc_allocate_device(&client->dev);
+ if (IS_ERR(priv->rtc))
+ return PTR_ERR(priv->rtc);
- rtc->ops = &abx80x_rtc_ops;
+ priv->rtc->ops = &abx80x_rtc_ops;
+ priv->client = client;
- i2c_set_clientdata(client, rtc);
+ i2c_set_clientdata(client, priv);
if (client->irq > 0) {
dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
@@ -649,7 +660,7 @@ static int abx80x_probe(struct i2c_client *client,
return err;
}
- err = rtc_register_device(rtc);
+ err = rtc_register_device(priv->rtc);
return err;
}
--
2.17.1
On Mon, Sep 10, 2018 at 03:36:54PM -0600, Jeremy Gebben wrote:
> The abx804 and abx805 chips have support for a simple watchdog
> function that can trigger an external reset.
>
> Signed-off-by: Jeremy Gebben <[email protected]>
I am missing the "select WATCHDOG_CORE" that would normally go
with watchdog drivers. If you don't want a separate configuration
option for the watchdog, you'll still need something like
select WATCHDOG_CORE if WATCHDOG
in the Kconfig entry for this driver.
> ---
> drivers/rtc/rtc-abx80x.c | 132 +++++++++++++++++++++++++++++++++++++--
> 1 file changed, 128 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/rtc/rtc-abx80x.c b/drivers/rtc/rtc-abx80x.c
> index 9d49054a0a4a..e1ec4cce093a 100644
> --- a/drivers/rtc/rtc-abx80x.c
> +++ b/drivers/rtc/rtc-abx80x.c
> @@ -17,6 +17,7 @@
> #include <linux/i2c.h>
> #include <linux/module.h>
> #include <linux/rtc.h>
> +#include <linux/watchdog.h>
>
> #define ABX8XX_REG_HTH 0x00
> #define ABX8XX_REG_SC 0x01
> @@ -37,6 +38,7 @@
>
> #define ABX8XX_REG_STATUS 0x0f
> #define ABX8XX_STATUS_AF BIT(2)
> +#define ABX8XX_STATUS_WDT BIT(6)
>
> #define ABX8XX_REG_CTRL1 0x10
> #define ABX8XX_CTRL_WRITE BIT(0)
> @@ -61,6 +63,14 @@
> #define ABX8XX_OSS_OF BIT(1)
> #define ABX8XX_OSS_OMODE BIT(4)
>
> +#define ABX8XX_REG_WDT 0x1b
> +#define ABX8XX_WDT_WDS BIT(7)
> +#define ABX8XX_WDT_BMB_MASK 0x7c
> +#define ABX8XX_WDT_BMB_SHIFT 2
> +#define ABX8XX_WDT_MAX_TIME (ABX8XX_WDT_BMB_MASK >> ABX8XX_WDT_BMB_SHIFT)
> +#define ABX8XX_WDT_WRB_MASK 0x03
> +#define ABX8XX_WDT_WRB_1HZ 0x02
> +
> #define ABX8XX_REG_CFG_KEY 0x1f
> #define ABX8XX_CFG_KEY_OSC 0xa1
> #define ABX8XX_CFG_KEY_MISC 0x9d
> @@ -80,23 +90,25 @@ enum abx80x_chip {AB0801, AB0803, AB0804, AB0805,
> struct abx80x_cap {
> u16 pn;
> bool has_tc;
> + bool has_wdog;
> };
>
> static struct abx80x_cap abx80x_caps[] = {
> [AB0801] = {.pn = 0x0801},
> [AB0803] = {.pn = 0x0803},
> - [AB0804] = {.pn = 0x0804, .has_tc = true},
> - [AB0805] = {.pn = 0x0805, .has_tc = true},
> + [AB0804] = {.pn = 0x0804, .has_tc = true, .has_wdog = true},
> + [AB0805] = {.pn = 0x0805, .has_tc = true, .has_wdog = true},
> [AB1801] = {.pn = 0x1801},
> [AB1803] = {.pn = 0x1803},
> - [AB1804] = {.pn = 0x1804, .has_tc = true},
> - [AB1805] = {.pn = 0x1805, .has_tc = true},
> + [AB1804] = {.pn = 0x1804, .has_tc = true, .has_wdog = true},
> + [AB1805] = {.pn = 0x1805, .has_tc = true, .has_wdog = true},
> [ABX80X] = {.pn = 0}
> };
>
> struct abx80x_priv {
> struct rtc_device *rtc;
> struct i2c_client *client;
> + struct watchdog_device wdog;
> };
>
> static int abx80x_is_rc_mode(struct i2c_client *client)
> @@ -234,6 +246,13 @@ static irqreturn_t abx80x_handle_irq(int irq, void *dev_id)
> if (status & ABX8XX_STATUS_AF)
> rtc_update_irq(rtc, 1, RTC_AF | RTC_IRQF);
>
> + /*
> + * It is unclear if we'll get an interrupt before the external
> + * reset kicks in.
> + */
> + if (status & ABX8XX_STATUS_WDT)
> + dev_alert(&client->dev, "watchdog timeout interrupt.\n");
> +
> i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS, 0);
>
> return IRQ_HANDLED;
> @@ -535,6 +554,105 @@ static void rtc_calib_remove_sysfs_group(void *_dev)
> sysfs_remove_group(&dev->kobj, &rtc_calib_attr_group);
> }
>
> +#ifdef CONFIG_WATCHDOG
> +
> +static inline u8 timeout_bits(unsigned int timeout)
> +{
> + return ((timeout << ABX8XX_WDT_BMB_SHIFT) & ABX8XX_WDT_BMB_MASK) |
> + ABX8XX_WDT_WRB_1HZ;
> +}
> +
> +static int __abx80x_wdog_set_timeout(struct watchdog_device *wdog,
> + unsigned int timeout)
> +{
> + struct abx80x_priv *priv = watchdog_get_drvdata(wdog);
> + u8 val = ABX8XX_WDT_WDS | timeout_bits(timeout);
> +
> + /*
> + * Writing any timeout to the WDT register resets the watchdog timer.
> + * Writing 0 disables it.
> + */
> + return i2c_smbus_write_byte_data(priv->client, ABX8XX_REG_WDT, val);
> +}
> +
> +static int abx80x_wdog_set_timeout(struct watchdog_device *wdog,
> + unsigned int new_timeout)
I'll leave multi-line alignment issues to the driver maintainer.
> +{
> + int err = __abx80x_wdog_set_timeout(wdog, new_timeout);
> +
This will unconditionally enable the watchdog, even if it is currently
disabled.
> + if (err)
> + return err;
> +
> + wdog->timeout = new_timeout;
> + return 0;
> +}
> +
> +static int abx80x_wdog_ping(struct watchdog_device *wdog)
> +{
> + return __abx80x_wdog_set_timeout(wdog, wdog->timeout);
> +}
> +
> +static int abx80x_wdog_start(struct watchdog_device *wdog)
> +{
> + int err = __abx80x_wdog_set_timeout(wdog, wdog->timeout);
> +
> + if (err)
> + return err;
> +
> + set_bit(WDOG_HW_RUNNING, &wdog->status);
This is only necessary if the watchdog is running at probe,
or if it can not be stopped.
> + return 0;
> +}
> +
> +static int abx80x_wdog_stop(struct watchdog_device *wdog)
> +{
> + int err = __abx80x_wdog_set_timeout(wdog, 0);
> +
> + if (err)
> + return err;
> +
> + clear_bit(WDOG_HW_RUNNING, &wdog->status);
This suggests that the watchdog can be stopped, thus it is
unnecessary to set or clear the bit.
> + return 0;
> +}
> +
> +static const struct watchdog_info abx80x_wdog_info = {
> + .identity = "abx80x watchdog",
> + .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
> +};
> +
> +static const struct watchdog_ops abx80x_wdog_ops = {
> + .owner = THIS_MODULE,
> + .start = abx80x_wdog_start,
> + .stop = abx80x_wdog_stop,
> + .ping = abx80x_wdog_ping,
> + .set_timeout = abx80x_wdog_set_timeout,
> +};
> +
> +static int abx80x_setup_watchdog(struct abx80x_priv *priv)
> +{
> + int err;
> +
> + priv->wdog.ops = &abx80x_wdog_ops;
> + priv->wdog.info = &abx80x_wdog_info;
> + priv->wdog.min_timeout = 1;
> + priv->wdog.max_timeout = ABX8XX_WDT_MAX_TIME;
priv->wdog.parent should be set.
> +
> + err = devm_watchdog_register_device(&priv->client->dev,
> + &priv->wdog);
> + if (err)
> + return err;
> +
> + watchdog_set_drvdata(&priv->wdog, priv);
This is too late and racy; it must be called prior to registration.
> + watchdog_init_timeout(&priv->wdog, ABX8XX_WDT_MAX_TIME,
> + &priv->client->dev);
This is quite pointless. Just set
priv->wdog.timeout = ABX8XX_WDT_MAX_TIME;
above (prior to registration). If the idea is to be able to pick
a timeout value from devicetree, you would still set the default
value above and make the call
watchdog_init_timeout(&priv->wdog, 0, &priv->client->dev);
but again prior to registration.
> + return 0;
> +}
> +#else
> +static int abx80x_setup_watchdog(struct abx80x_priv *priv)
> +{
> + return 0;
> +}
> +#endif
> +
> static int abx80x_probe(struct i2c_client *client,
> const struct i2c_device_id *id)
> {
> @@ -629,6 +747,12 @@ static int abx80x_probe(struct i2c_client *client,
>
> i2c_set_clientdata(client, priv);
>
> + if (abx80x_caps[part].has_wdog) {
> + err = abx80x_setup_watchdog(priv);
> + if (err)
> + return err;
> + }
> +
> if (client->irq > 0) {
> dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
> err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
> --
> 2.17.1
>
On 10/09/2018 16:20:19-0700, Guenter Roeck wrote:
> > +static int abx80x_wdog_set_timeout(struct watchdog_device *wdog,
> > + unsigned int new_timeout)
>
> I'll leave multi-line alignment issues to the driver maintainer.
>
Indeed, I'd like those to be aligned on the parenthesis.
Thank you for your review.
--
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com