lkml.org 
[lkml]   [2018]   [Sep]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] rtc: abx80x: add basic watchdog support
Hi,

Please Cc the watchdog maintainers. Else, I have very few comments.

On 07/09/2018 09:17:43-0600, 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 <jgebben@sweptlaser.com>
> ---
> drivers/rtc/Kconfig | 11 +++
> drivers/rtc/rtc-abx80x.c | 160 ++++++++++++++++++++++++++++++++++++---
> 2 files changed, 159 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
> index 7d7be60a2413..4771e3a89721 100644
> --- a/drivers/rtc/Kconfig
> +++ b/drivers/rtc/Kconfig
> @@ -195,6 +195,17 @@ config RTC_DRV_ABX80X
> This driver can also be built as a module. If so, the module
> will be called rtc-abx80x.
>
> +config RTC_DRV_ABX80X_WDT
> + bool "Abracon ABx80x Watchdog"
> + default y
> + depends on RTC_DRV_ABX80X
> + help
> + If you say yes here you get watchdog support for Abracon ABX804 and ABX805
> + clock chips. This watchdog supports timeouts up to 31 seconds with 1 second
> + granularity.
> +
> + This watchdog device is part of the rtc-abx80x module.
> +

I'm not sure it is worth having a separate config option for that. You
may as well just always include the watchdog support code. However,
doesn't it need to depend on CONFIG_WATCHDOG?

> config RTC_DRV_AC100
> tristate "X-Powers AC100"
> depends on MFD_AC100
> diff --git a/drivers/rtc/rtc-abx80x.c b/drivers/rtc/rtc-abx80x.c
> index 2cefa67a1132..fa558939e944 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
> @@ -80,20 +90,27 @@ 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;
> +};
> +

To make the watchdog part easier to review, you could separate the
introduction of abx80x_priv in a preliminary patch and then introduce
the watchdog code.

> static int abx80x_is_rc_mode(struct i2c_client *client)
> {
> int flags = 0;
> @@ -218,7 +235,8 @@ 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);
> @@ -228,6 +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_err(&client->dev, "watchdog timeout interrupt!\n");
> +

dev_alert maybe?

> i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS, 0);
>
> return IRQ_HANDLED;
> @@ -529,11 +554,110 @@ static void rtc_calib_remove_sysfs_group(void *_dev)
> sysfs_remove_group(&dev->kobj, &rtc_calib_attr_group);
> }
>
> +#ifdef CONFIG_RTC_DRV_ABX80X_WDT
> +
> +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)
> {
> 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 +734,25 @@ 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(struct abx80x_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 (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);
> @@ -649,7 +785,7 @@ 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
>

--
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

\
 
 \ /
  Last update: 2018-09-08 17:10    [W:0.161 / U:6.752 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site