[PATCH v1 0/2] rtc: update ds1388 support

[PATCH v1 0/2] rtc: update ds1388 support

[Chris Packham]

The ds1388 as a slightly different register layout and watchdog timer
capabilities. Add support for both of these.

Chris Packham (2):
  rtc: ds1307: handle oscillator failure flags for ds1388 variant
  rtc: ds1307: add support for watchdog timer on ds1388

 drivers/rtc/rtc-ds1307.c | 114 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 114 insertions(+)

-- 
2.25.0

[PATCH v1 1/2] rtc: ds1307: handle oscillator failure flags for ds1388 variant

[Chris Packham]

The FLAG register is at a different location to the other supported RTCs
so this requires an extra case in the existing switch statement.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
---
 drivers/rtc/rtc-ds1307.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index 1f7e8aefc1eb..31a38d468378 100644
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -144,6 +144,8 @@ enum ds_type {
 #	define M41TXX_BIT_CALIB_SIGN	BIT(5)
 #	define M41TXX_M_CALIBRATION	GENMASK(4, 0)
 
+#define DS1388_REG_FLAG			0x0b
+#	define DS1388_BIT_OSF		BIT(7)
 /* negative offset step is -2.034ppm */
 #define M41TXX_NEG_OFFSET_STEP_PPB	2034
 /* positive offset step is +4.068ppm */
@@ -252,6 +254,13 @@ static int ds1307_get_time(struct device *dev, struct rtc_time *t)
 		if (tmp & DS1340_BIT_OSF)
 			return -EINVAL;
 		break;
+	case ds_1388:
+		ret = regmap_read(ds1307->regmap, DS1388_REG_FLAG, &tmp);
+		if (ret)
+			return ret;
+		if (tmp & DS1388_BIT_OSF)
+			return -EINVAL;
+		break;
 	case mcp794xx:
 		if (!(tmp & MCP794XX_BIT_ST))
 			return -EINVAL;
-- 
2.25.0

[PATCH v1 2/2] rtc: ds1307: add support for watchdog timer on ds1388

[Chris Packham]

The DS1388 variant has watchdog timer capabilities. When using a DS1388
and having enabled CONFIG_WATCHDOG_CORE register a watchdog device for
the DS1388.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
---
 drivers/rtc/rtc-ds1307.c | 105 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 105 insertions(+)

diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index 31a38d468378..e83d9e52aae5 100644
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -22,6 +22,7 @@
 #include <linux/hwmon-sysfs.h>
 #include <linux/clk-provider.h>
 #include <linux/regmap.h>
+#include <linux/watchdog.h>
 
 /*
  * We can't determine type by probing, but if we expect pre-Linux code
@@ -144,8 +145,15 @@ enum ds_type {
 #	define M41TXX_BIT_CALIB_SIGN	BIT(5)
 #	define M41TXX_M_CALIBRATION	GENMASK(4, 0)
 
+#define DS1388_REG_WDOG_HUN_SECS	0x08
+#define DS1388_REG_WDOG_SECS		0x09
 #define DS1388_REG_FLAG			0x0b
+#	define DS1388_BIT_WF		BIT(6)
 #	define DS1388_BIT_OSF		BIT(7)
+#define DS1388_REG_CONTROL		0x0c
+#	define DS1388_BIT_RST		BIT(0)
+#	define DS1388_BIT_WDE		BIT(1)
+
 /* negative offset step is -2.034ppm */
 #define M41TXX_NEG_OFFSET_STEP_PPB	2034
 /* positive offset step is +4.068ppm */
@@ -166,6 +174,9 @@ struct ds1307 {
 #ifdef CONFIG_COMMON_CLK
 	struct clk_hw		clks[2];
 #endif
+#ifdef CONFIG_WATCHDOG_CORE
+	struct watchdog_device	wdt;
+#endif
 };
 
 struct chip_desc {
@@ -854,6 +865,58 @@ static int m41txx_rtc_set_offset(struct device *dev, long offset)
 				  ctrl_reg);
 }
 
+#ifdef CONFIG_WATCHDOG_CORE
+static int ds1388_wdt_start(struct watchdog_device *wdt_dev)
+{
+	struct ds1307 *ds1307 = watchdog_get_drvdata(wdt_dev);
+	u8 regs[2];
+	int ret;
+
+	ret = regmap_update_bits(ds1307->regmap, DS1388_REG_FLAG,
+			DS1388_BIT_WF, 0);
+	if (ret)
+		return ret;
+
+	ret = regmap_update_bits(ds1307->regmap, DS1388_REG_CONTROL,
+				 DS1388_BIT_WDE|DS1388_BIT_RST, 0);
+	if (ret)
+		return ret;
+
+	/*
+	 * watchdog timeouts are measured in seconds so max out hundreths of
+	 * seconds field.
+	 */
+	regs[0] = 0x99;
+	regs[1] = bin2bcd(wdt_dev->timeout);
+
+	ret = regmap_bulk_write(ds1307->regmap, DS1388_REG_WDOG_HUN_SECS, regs,
+			sizeof(regs));
+	if (ret)
+		return ret;
+
+	return regmap_update_bits(ds1307->regmap, DS1388_REG_CONTROL,
+				  DS1388_BIT_WDE|DS1388_BIT_RST,
+				  DS1388_BIT_WDE|DS1388_BIT_RST);
+}
+
+static int ds1388_wdt_stop(struct watchdog_device *wdt_dev)
+{
+	struct ds1307 *ds1307 = watchdog_get_drvdata(wdt_dev);
+
+	return regmap_update_bits(ds1307->regmap, DS1388_REG_CONTROL,
+				  DS1388_BIT_WDE|DS1388_BIT_RST, 0);
+}
+
+static int ds1388_wdt_ping(struct watchdog_device *wdt_dev)
+{
+	struct ds1307 *ds1307 = watchdog_get_drvdata(wdt_dev);
+	u8 regs[2];
+
+	return regmap_bulk_read(ds1307->regmap, DS1388_REG_WDOG_HUN_SECS, regs,
+				sizeof(regs));
+}
+#endif
+
 static const struct rtc_class_ops rx8130_rtc_ops = {
 	.read_time      = ds1307_get_time,
 	.set_time       = ds1307_set_time,
@@ -880,6 +943,20 @@ static const struct rtc_class_ops m41txx_rtc_ops = {
 	.set_offset	= m41txx_rtc_set_offset,
 };
 
+#ifdef CONFIG_WATCHDOG_CORE
+static const struct watchdog_info ds1388_wdt_info = {
+	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+	.identity = "DS1388 watchdog",
+};
+
+static const struct watchdog_ops ds1388_wdt_ops = {
+	.owner = THIS_MODULE,
+	.start = ds1388_wdt_start,
+	.stop = ds1388_wdt_stop,
+	.ping = ds1388_wdt_ping,
+};
+#endif
+
 static const struct chip_desc chips[last_ds_type] = {
 	[ds_1307] = {
 		.nvram_offset	= 8,
@@ -1576,6 +1653,33 @@ static void ds1307_clks_register(struct ds1307 *ds1307)
 
 #endif /* CONFIG_COMMON_CLK */
 
+#ifdef CONFIG_WATCHDOG_CORE
+static void ds1307_wdt_register(struct ds1307 *ds1307)
+{
+	int ret;
+
+	if (ds1307->type != ds_1388)
+		return;
+
+	ds1307->wdt.info = &ds1388_wdt_info;
+	ds1307->wdt.ops = &ds1388_wdt_ops;
+	ds1307->wdt.max_timeout = 99;
+	ds1307->wdt.min_timeout = 1;
+
+	watchdog_init_timeout(&ds1307->wdt, 99, ds1307->dev);
+	watchdog_set_drvdata(&ds1307->wdt, ds1307);
+	ret = watchdog_register_device(&ds1307->wdt);
+	if (ret) {
+		dev_warn(ds1307->dev, "unable to register watchdog device %d\n",
+			 ret);
+	}
+}
+#else
+static void ds1307_wdt_register(struct ds1307 *ds1307)
+{
+}
+#endif /* CONFIG_WATCHDOG_CORE */
+
 static const struct regmap_config regmap_config = {
 	.reg_bits = 8,
 	.val_bits = 8,
@@ -1865,6 +1969,7 @@ static int ds1307_probe(struct i2c_client *client,
 
 	ds1307_hwmon_register(ds1307);
 	ds1307_clks_register(ds1307);
+	ds1307_wdt_register(ds1307);
 
 	return 0;
 
-- 
2.25.0

Re: [PATCH v1 0/2] rtc: update ds1388 support

[Chris Packham]

Hi All,

On Fri, 2020-02-07 at 16:18 +1300, Chris Packham wrote:
> The ds1388 as a slightly different register layout and watchdog timer
> capabilities. Add support for both of these.
> 
> Chris Packham (2):
>   rtc: ds1307: handle oscillator failure flags for ds1388 variant
>   rtc: ds1307: add support for watchdog timer on ds1388
> 
>  drivers/rtc/rtc-ds1307.c | 114 +++++++++++++++++++++++++++++++++++++++
>  1 file changed, 114 insertions(+)
> 

Been a while with no response on this. Friendly ping.

Re: [PATCH v1 1/2] rtc: ds1307: handle oscillator failure flags for ds1388 variant

[Alexandre Belloni]

On 07/02/2020 16:18:11+1300, Chris Packham wrote:
> The FLAG register is at a different location to the other supported RTCs
> so this requires an extra case in the existing switch statement.
> 
> Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
> ---
>  drivers/rtc/rtc-ds1307.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
Applied, thanks.

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

Re: [PATCH v1 2/2] rtc: ds1307: add support for watchdog timer on ds1388

[Alexandre Belloni]

Hi,

On 07/02/2020 16:18:12+1300, Chris Packham wrote:
> The DS1388 variant has watchdog timer capabilities. When using a DS1388
> and having enabled CONFIG_WATCHDOG_CORE register a watchdog device for
> the DS1388.
> 

As this is a watchdog related patch, you should copy the watchdog
maintainers too.

> +#ifdef CONFIG_WATCHDOG_CORE
> +static int ds1388_wdt_start(struct watchdog_device *wdt_dev)
> +{
> +	struct ds1307 *ds1307 = watchdog_get_drvdata(wdt_dev);
> +	u8 regs[2];
> +	int ret;
> +
> +	ret = regmap_update_bits(ds1307->regmap, DS1388_REG_FLAG,
> +			DS1388_BIT_WF, 0);

This is not properly aligned.

> +	if (ret)
> +		return ret;
> +
> +	ret = regmap_update_bits(ds1307->regmap, DS1388_REG_CONTROL,
> +				 DS1388_BIT_WDE|DS1388_BIT_RST, 0);
spaces around the '|' please

> +	if (ret)
> +		return ret;
> +
> +	/*
> +	 * watchdog timeouts are measured in seconds so max out hundreths of
> +	 * seconds field.
> +	 */
> +	regs[0] = 0x99;

Doesn't that give an extra second to the timeout?

> +	regs[1] = bin2bcd(wdt_dev->timeout);
> +
> +	ret = regmap_bulk_write(ds1307->regmap, DS1388_REG_WDOG_HUN_SECS, regs,
> +			sizeof(regs));

This is not properly aligned

> +	if (ret)
> +		return ret;
> +
> +	return regmap_update_bits(ds1307->regmap, DS1388_REG_CONTROL,
> +				  DS1388_BIT_WDE|DS1388_BIT_RST,
> +				  DS1388_BIT_WDE|DS1388_BIT_RST);

spaces around the '|'

> +}
> +
> +static int ds1388_wdt_stop(struct watchdog_device *wdt_dev)
> +{
> +	struct ds1307 *ds1307 = watchdog_get_drvdata(wdt_dev);
> +
> +	return regmap_update_bits(ds1307->regmap, DS1388_REG_CONTROL,
> +				  DS1388_BIT_WDE|DS1388_BIT_RST, 0);

ditto

> +}
> +
> +static int ds1388_wdt_ping(struct watchdog_device *wdt_dev)
> +{
> +	struct ds1307 *ds1307 = watchdog_get_drvdata(wdt_dev);
> +	u8 regs[2];
> +
> +	return regmap_bulk_read(ds1307->regmap, DS1388_REG_WDOG_HUN_SECS, regs,
> +				sizeof(regs));
> +}
> +#endif
> +
>  static const struct rtc_class_ops rx8130_rtc_ops = {
>  	.read_time      = ds1307_get_time,
>  	.set_time       = ds1307_set_time,
> @@ -880,6 +943,20 @@ static const struct rtc_class_ops m41txx_rtc_ops = {
>  	.set_offset	= m41txx_rtc_set_offset,
>  };
>  
> +#ifdef CONFIG_WATCHDOG_CORE
> +static const struct watchdog_info ds1388_wdt_info = {
> +	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
> +	.identity = "DS1388 watchdog",
> +};
> +
> +static const struct watchdog_ops ds1388_wdt_ops = {
> +	.owner = THIS_MODULE,
> +	.start = ds1388_wdt_start,
> +	.stop = ds1388_wdt_stop,
> +	.ping = ds1388_wdt_ping,
> +};

Both those structs should be move just before ds1307_wdt_register to
avoid the #ifdef duplication

> +#endif
> +
>  static const struct chip_desc chips[last_ds_type] = {
>  	[ds_1307] = {
>  		.nvram_offset	= 8,
> @@ -1576,6 +1653,33 @@ static void ds1307_clks_register(struct ds1307 *ds1307)
>  
>  #endif /* CONFIG_COMMON_CLK */
>  
> +#ifdef CONFIG_WATCHDOG_CORE
> +static void ds1307_wdt_register(struct ds1307 *ds1307)
> +{
> +	int ret;
> +
> +	if (ds1307->type != ds_1388)
> +		return;
> +
> +	ds1307->wdt.info = &ds1388_wdt_info;
> +	ds1307->wdt.ops = &ds1388_wdt_ops;
> +	ds1307->wdt.max_timeout = 99;
> +	ds1307->wdt.min_timeout = 1;
> +
> +	watchdog_init_timeout(&ds1307->wdt, 99, ds1307->dev);
> +	watchdog_set_drvdata(&ds1307->wdt, ds1307);
> +	ret = watchdog_register_device(&ds1307->wdt);
> +	if (ret) {
> +		dev_warn(ds1307->dev, "unable to register watchdog device %d\n",
> +			 ret);

There is already a message in case of failure in
watchdog_register_device. Is it really necessary to have a second one?

> +	}
> +}
> +#else
> +static void ds1307_wdt_register(struct ds1307 *ds1307)
> +{
> +}
> +#endif /* CONFIG_WATCHDOG_CORE */
> +
>  static const struct regmap_config regmap_config = {
>  	.reg_bits = 8,
>  	.val_bits = 8,
> @@ -1865,6 +1969,7 @@ static int ds1307_probe(struct i2c_client *client,
>  
>  	ds1307_hwmon_register(ds1307);
>  	ds1307_clks_register(ds1307);
> +	ds1307_wdt_register(ds1307);
>  
>  	return 0;
>  
> -- 
> 2.25.0
> 

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