Re: [PATCH v3 3/4] rtc: isl1208: add support for isl1219 with tamper detection

[Alexandre Belloni]

On 05/03/2018 at 10:43:52 +0000, Denis OSTERLAND wrote:
> diff --git a/Documentation/devicetree/bindings/rtc/isil,isl1219.txt b/Documentation/devicetree/bindings/rtc/isil,isl1219.txt
> new file mode 100644
> index 0000000..7937c13
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/rtc/isil,isl1219.txt

If you want that file to be reviewed by Rob (DT maintainer), you should
probably separate it from that patch and copy his email. The bindings
seem fine to me though.

> diff --git a/drivers/rtc/rtc-isl1208.c b/drivers/rtc/rtc-isl1208.c
> index 1a2c38c..164371b 100644
> --- a/drivers/rtc/rtc-isl1208.c
> +++ b/drivers/rtc/rtc-isl1208.c
> @@ -33,6 +33,7 @@
>  #define ISL1208_REG_SR_ARST    (1<<7)	/* auto reset */
>  #define ISL1208_REG_SR_XTOSCB  (1<<6)	/* crystal oscillator */
>  #define ISL1208_REG_SR_WRTC    (1<<4)	/* write rtc */
> +#define ISL1208_REG_SR_EVT     (1<<3)	/* event */
>  #define ISL1208_REG_SR_ALM     (1<<2)	/* alarm */
>  #define ISL1208_REG_SR_BAT     (1<<1)	/* battery */
>  #define ISL1208_REG_SR_RTCF    (1<<0)	/* rtc fail */
> @@ -57,8 +58,29 @@
>  #define ISL1208_REG_USR2 0x13
>  #define ISL1208_USR_SECTION_LEN 2
> 
> +/* event section */
> +#define ISL1208_REG_SCT 0x14
> +#define ISL1208_REG_MNT 0x15
> +#define ISL1208_REG_HRT 0x16
> +#define ISL1208_REG_DTT 0x17
> +#define ISL1208_REG_MOT 0x18
> +#define ISL1208_REG_YRT 0x19
> +#define ISL1208_EVT_SECTION_LEN 6
> +

Because they are not available on ISL1208, maybe it would be better to
prefix them with ISL1219.

> +
> +	tv64.tv_sec = rtc_tm_to_time64(&tm);

Why not using an unsigned long long directly here? time64_t is not the
correct type.

> +
> +	return sprintf(buf, "%lld\n", (long long) tv64.tv_sec);

And this should become %llu

> +};
> +
> +static DEVICE_ATTR(timestamp0, 0640,

Shouldn't the permissions be 644?

> +		isl1208_rtc_event_show_timestamp, isl1208_rtc_event_clear);
> +
>  static irqreturn_t
>  isl1208_rtc_interrupt(int irq, void *data)
>  {
>  	unsigned long timeout = jiffies + msecs_to_jiffies(1000);
>  	struct i2c_client *client = data;
> -	struct rtc_device *rtc = i2c_get_clientdata(client);
> +	struct isl1208 *isl1208 = i2c_get_clientdata(client);
>  	int handled = 0, sr, err;
> 
>  	/*
> @@ -521,7 +609,7 @@ isl1208_rtc_interrupt(int irq, void *data)
>  	if (sr & ISL1208_REG_SR_ALM) {
>  		dev_dbg(&client->dev, "alarm!\n");
> 
> -		rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF);
> +		rtc_update_irq(isl1208->rtc, 1, RTC_IRQF | RTC_AF);
> 
>  		/* Clear the alarm */
>  		sr &= ~ISL1208_REG_SR_ALM;
> @@ -538,6 +626,13 @@ isl1208_rtc_interrupt(int irq, void *data)
>  			return err;
>  	}
> 
> +	if (sr & ISL1208_REG_SR_EVT) {
> +		sysfs_notify(&client->dev.kobj, NULL,
> +			dev_attr_timestamp0.attr.name);
> +		dev_warn(&client->dev, "event detected");
> +		handled = 1;
> +	}
> +
>  	return handled ? IRQ_HANDLED : IRQ_NONE;
>  }
> 
> @@ -623,11 +718,23 @@ static const struct attribute_group isl1208_rtc_sysfs_files = {
>  	.attrs	= isl1208_rtc_attrs,
>  };
> 
> +static struct attribute *isl1219_rtc_attrs[] = {
> +	&dev_attr_atrim.attr,
> +	&dev_attr_dtrim.attr,
> +	&dev_attr_usr.attr,
> +	&dev_attr_timestamp0.attr,
> +	NULL
> +};
> +
> +static const struct attribute_group isl1219_rtc_sysfs_files = {
> +	.attrs	= isl1219_rtc_attrs,
> +};
> +
>  static int
>  isl1208_probe(struct i2c_client *client, const struct i2c_device_id *id)
>  {
>  	int rc = 0;
> -	struct rtc_device *rtc;
> +	struct isl1208 *isl1208;
> 
>  	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
>  		return -ENODEV;
> @@ -635,13 +742,18 @@ isl1208_probe(struct i2c_client *client, const struct i2c_device_id *id)
>  	if (isl1208_i2c_validate_client(client) < 0)
>  		return -ENODEV;
> 
> -	rtc = devm_rtc_allocate_device(&client->dev);
> -	if (IS_ERR(rtc))
> -		return PTR_ERR(rtc);
> +	isl1208 = devm_kzalloc(&client->dev, sizeof(struct isl1208),
> +				GFP_KERNEL);
> +	if (!isl1208)
> +		return -ENOMEM;
> 
> -	rtc->ops = &isl1208_rtc_ops;
> +	isl1208->rtc = devm_rtc_allocate_device(&client->dev);
> +	if (IS_ERR(isl1208->rtc))
> +		return PTR_ERR(isl1208->rtc);
> 
> -	i2c_set_clientdata(client, rtc);
> +	isl1208->rtc->ops = &isl1208_rtc_ops;
> +
> +	i2c_set_clientdata(client, isl1208);
> 
>  	rc = isl1208_i2c_get_sr(client);
>  	if (rc < 0) {
> @@ -653,7 +765,18 @@ isl1208_probe(struct i2c_client *client, const struct i2c_device_id *id)
>  		dev_warn(&client->dev, "rtc power failure detected, "
>  			 "please set clock.\n");
> 
> -	rc = sysfs_create_group(&client->dev.kobj, &isl1208_rtc_sysfs_files);
> +	if (id->driver_data == TYPE_ISL1219) {
> +		rc = i2c_smbus_write_byte_data(client, ISL1208_REG_09, 0x10);
> +		if (rc < 0) {
> +			dev_err(&client->dev, "could not enable tamper detection\n");
> +			return rc;
> +		}
> +		isl1208->sysfs_files = &isl1219_rtc_sysfs_files;
> +	} else {
> +		isl1208->sysfs_files = &isl1208_rtc_sysfs_files;
> +	}
> +

I don't think the whole isl1208 is necessary. You should probably use
the .is_visible callback of isl1219_rtc_sysfs_files. This will make the
changelog quite smaller.

> +	rc = sysfs_create_group(&client->dev.kobj, isl1208->sysfs_files);
>  	if (rc)
>  		return rc;
> 
> @@ -674,20 +797,23 @@ isl1208_probe(struct i2c_client *client, const struct i2c_device_id *id)
>  		}
>  	}
> 
> -	return rtc_register_device(rtc);
> +	return rtc_register_device(isl1208->rtc);
>  }
> 
>  static int
>  isl1208_remove(struct i2c_client *client)
>  {
> -	sysfs_remove_group(&client->dev.kobj, &isl1208_rtc_sysfs_files);
> +	struct isl1208 *isl1208 = i2c_get_clientdata(client);
> +
> +	sysfs_remove_group(&client->dev.kobj, isl1208->sysfs_files);
> 
>  	return 0;
>  }
> 
>  static const struct i2c_device_id isl1208_id[] = {
> -	{ "isl1208", 0 },
> -	{ "isl1218", 0 },
> +	{ "isl1208", TYPE_ISL1208 },
> +	{ "isl1218", TYPE_ISL1218 },
> +	{ "isl1219", TYPE_ISL1219 },
>  	{ }
>  };
>  MODULE_DEVICE_TABLE(i2c, isl1208_id);
> --
> 2.7.4
> 
> 
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-- 
Alexandre Belloni, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com