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mfd: max77686: Fix parent of rtc device

PATCH New Yadwinder Singh Brar 2 participants 6 messages Dec 2, 2014 – Dec 3, 2014

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#0 lore raw

PATCH 1/1 mfd: max77686: Fix parent of rtc device

rtc have different i2c client than power(pmic) block. So rtc device should sit under its own i2c client in device hierarchy, which reflects in sysfs also. This patch modifies code to register rtc cell with rtc->dev as parent.

Without this patch :

driver         max77686-pmic  modalias       power          uevent
max77686-clk   max77686-rtc   name           subsystem

After applying patch :

driver/        modalias       power/         uevent
max77686-rtc/  name           subsystem/

---

Or Can we follow another (exhaustive but more cleaner) approach, which will be more like code refactoring and cleanup rather than only fix:
Since rtc uses i2c client, which gets created using i2c_new_dummy() and is not shared by any other cell of max77686. So we can covert rtc platform driver itself to i2c client driver. It will also allow to expilicitly describe max77686-rtc in DT which we can't do now.
It can be applicable to some other existing and new mfd pmic drivers. Any suggestion/comments ?

---
 drivers/mfd/max77686.c |   22 ++++++++++++++++++++--
 1 files changed, 20 insertions(+), 2 deletions(-)
drivers/mfd/max77686.c +20 -2
index 929795e..22c0948 100644
@@ -39,10 +39,13 @@
 
 static const struct mfd_cell max77686_devs[] = {
 	{ .name = "max77686-pmic", },
-	{ .name = "max77686-rtc", },
 	{ .name = "max77686-clk", },
 };
 
+static const struct mfd_cell max77686_rtc_dev[] = {
+	{ .name = "max77686-rtc", },
+};
+
 static const struct mfd_cell max77802_devs[] = {
 	{ .name = "max77802-pmic", },
 	{ .name = "max77802-clk", },
@@ -332,14 +335,27 @@ static int max77686_i2c_probe(struct i2c_client *i2c,
 		goto err_del_irqc;
 	}
 
+	if (max77686->type == TYPE_MAX77686) {
+		ret = mfd_add_devices(&max77686->rtc->dev, -1, max77686_rtc_dev,
+			1, NULL, 0, NULL);
+		if (ret < 0) {
+			dev_err(&max77686->rtc->dev,
+				"failed to add RTC device %d\n", ret);
+			goto err_del_rtc_irqc;
+		}
+	}
+
 	ret = mfd_add_devices(max77686->dev, -1, cells, n_devs, NULL, 0, NULL);
 	if (ret < 0) {
 		dev_err(&i2c->dev, "failed to add MFD devices: %d\n", ret);
-		goto err_del_rtc_irqc;
+		goto err_del_rtc_dev;
 	}
 
 	return 0;
 
+err_del_rtc_dev:
+	if (max77686->type == TYPE_MAX77686)
+		mfd_remove_devices(&max77686->rtc->dev);
 err_del_rtc_irqc:
 	regmap_del_irq_chip(max77686->irq, max77686->rtc_irq_data);
 err_del_irqc:
@@ -356,6 +372,8 @@ static int max77686_i2c_remove(struct i2c_client *i2c)
 	struct max77686_dev *max77686 = i2c_get_clientdata(i2c);
 
 	mfd_remove_devices(max77686->dev);
+	if (max77686->type == TYPE_MAX77686)
+		mfd_remove_devices(&max77686->rtc->dev);
 
 	regmap_del_irq_chip(max77686->irq, max77686->rtc_irq_data);
 	regmap_del_irq_chip(max77686->irq, max77686->irq_data);
Signature · 1 line
1.7.0.4
#1 lore raw

PATCH 1/1 mfd: max77686: Fix parent of rtc device

rtc have different i2c client than power(pmic) block. So rtc device should sit under its own i2c client in device hierarchy, which reflects in sysfs also. This patch modifies code to register rtc cell with rtc->dev as parent.

Without this patch :

# ls /sys/class/i2c-adapter/i2c-0/0-0009/
driver         max77686-pmic  modalias       power          uevent
max77686-clk   max77686-rtc   name           subsystem

After applying patch :

# ls /sys/class/i2c-adapter/i2c-0/0-0006/
driver/        modalias       power/         uevent
max77686-rtc/  name           subsystem/

---

Or Can we follow another (exhaustive but more cleaner) approach, which will be more like code refactoring and cleanup rather than only fix:
Since rtc uses i2c client, which gets created using i2c_new_dummy() and is not shared by any other cell of max77686. So we can covert rtc platform driver itself to i2c client driver. It will also allow to expilicitly describe max77686-rtc in DT which we can't do now.
It can be applicable to some other existing and new mfd pmic drivers. Any suggestion/comments ?

---
 drivers/mfd/max77686.c |   22 ++++++++++++++++++++--
 1 files changed, 20 insertions(+), 2 deletions(-)
drivers/mfd/max77686.c +20 -2
index 929795e..22c0948 100644
@@ -39,10 +39,13 @@
 
 static const struct mfd_cell max77686_devs[] = {
 	{ .name = "max77686-pmic", },
-	{ .name = "max77686-rtc", },
 	{ .name = "max77686-clk", },
 };
 
+static const struct mfd_cell max77686_rtc_dev[] = {
+	{ .name = "max77686-rtc", },
+};
+
 static const struct mfd_cell max77802_devs[] = {
 	{ .name = "max77802-pmic", },
 	{ .name = "max77802-clk", },
@@ -332,14 +335,27 @@ static int max77686_i2c_probe(struct i2c_client *i2c,
 		goto err_del_irqc;
 	}
 
+	if (max77686->type == TYPE_MAX77686) {
+		ret = mfd_add_devices(&max77686->rtc->dev, -1, max77686_rtc_dev,
+			1, NULL, 0, NULL);
+		if (ret < 0) {
+			dev_err(&max77686->rtc->dev,
+				"failed to add RTC device %d\n", ret);
+			goto err_del_rtc_irqc;
+		}
+	}
+
 	ret = mfd_add_devices(max77686->dev, -1, cells, n_devs, NULL, 0, NULL);
 	if (ret < 0) {
 		dev_err(&i2c->dev, "failed to add MFD devices: %d\n", ret);
-		goto err_del_rtc_irqc;
+		goto err_del_rtc_dev;
 	}
 
 	return 0;
 
+err_del_rtc_dev:
+	if (max77686->type == TYPE_MAX77686)
+		mfd_remove_devices(&max77686->rtc->dev);
 err_del_rtc_irqc:
 	regmap_del_irq_chip(max77686->irq, max77686->rtc_irq_data);
 err_del_irqc:
@@ -356,6 +372,8 @@ static int max77686_i2c_remove(struct i2c_client *i2c)
 	struct max77686_dev *max77686 = i2c_get_clientdata(i2c);
 
 	mfd_remove_devices(max77686->dev);
+	if (max77686->type == TYPE_MAX77686)
+		mfd_remove_devices(&max77686->rtc->dev);
 
 	regmap_del_irq_chip(max77686->irq, max77686->rtc_irq_data);
 	regmap_del_irq_chip(max77686->irq, max77686->irq_data);
Signature · 1 line
1.7.0.4
#2 lore raw

PATCH 1/1 mfd: max77686: Fix parent of rtc device

Quoted 17 lines · Yadwinder Singh Brar

rtc have different i2c client than power(pmic) block. So rtc device should sit under its own i2c client in device hierarchy, which reflects in sysfs also. This patch modifies code to register rtc cell with rtc->dev as parent.

Without this patch :

# ls /sys/class/i2c-adapter/i2c-0/0-0009/
driver         max77686-pmic  modalias       power          uevent
max77686-clk   max77686-rtc   name           subsystem

After applying patch :

# ls /sys/class/i2c-adapter/i2c-0/0-0006/
driver/        modalias       power/         uevent
max77686-rtc/  name           subsystem/

---

Quoted 8 lines

Or Can we follow another (exhaustive but more cleaner) approach, which will be more like code refactoring and cleanup rather than only fix:
Since rtc uses i2c client, which gets created using i2c_new_dummy() and is not shared by any other cell of max77686. So we can covert rtc platform driver itself to i2c client driver. It will also allow to expilicitly describe max77686-rtc in DT which we can't do now.
It can be applicable to some other existing and new mfd pmic drivers. Any suggestion/comments ?

Hi,

What kind of problem is solved by this patch?

Best regards,
Krzysztof

Quoted 63 lines
---
 drivers/mfd/max77686.c |   22 ++++++++++++++++++++--
 1 files changed, 20 insertions(+), 2 deletions(-)
drivers/mfd/max77686.c +20 -2
index 929795e..22c0948 100644
@@ -39,10 +39,13 @@
 
 static const struct mfd_cell max77686_devs[] = {
 	{ .name = "max77686-pmic", },
-	{ .name = "max77686-rtc", },
 	{ .name = "max77686-clk", },
 };
 
+static const struct mfd_cell max77686_rtc_dev[] = {
+	{ .name = "max77686-rtc", },
+};
+
 static const struct mfd_cell max77802_devs[] = {
 	{ .name = "max77802-pmic", },
 	{ .name = "max77802-clk", },
@@ -332,14 +335,27 @@ static int max77686_i2c_probe(struct i2c_client *i2c,
 		goto err_del_irqc;
 	}
 
+	if (max77686->type == TYPE_MAX77686) {
+		ret = mfd_add_devices(&max77686->rtc->dev, -1, max77686_rtc_dev,
+			1, NULL, 0, NULL);
+		if (ret < 0) {
+			dev_err(&max77686->rtc->dev,
+				"failed to add RTC device %d\n", ret);
+			goto err_del_rtc_irqc;
+		}
+	}
+
 	ret = mfd_add_devices(max77686->dev, -1, cells, n_devs, NULL, 0, NULL);
 	if (ret < 0) {
 		dev_err(&i2c->dev, "failed to add MFD devices: %d\n", ret);
-		goto err_del_rtc_irqc;
+		goto err_del_rtc_dev;
 	}
 
 	return 0;
 
+err_del_rtc_dev:
+	if (max77686->type == TYPE_MAX77686)
+		mfd_remove_devices(&max77686->rtc->dev);
 err_del_rtc_irqc:
 	regmap_del_irq_chip(max77686->irq, max77686->rtc_irq_data);
 err_del_irqc:
@@ -356,6 +372,8 @@ static int max77686_i2c_remove(struct i2c_client *i2c)
 	struct max77686_dev *max77686 = i2c_get_clientdata(i2c);
 
 	mfd_remove_devices(max77686->dev);
+	if (max77686->type == TYPE_MAX77686)
+		mfd_remove_devices(&max77686->rtc->dev);
 
 	regmap_del_irq_chip(max77686->irq, max77686->rtc_irq_data);
 	regmap_del_irq_chip(max77686->irq, max77686->irq_data);
#3 lore raw

PATCH 1/1 mfd: max77686: Fix parent of rtc device

Quoted 30 lines · Krzysztof Kozłowski
Quoted 2 lines · Yadwinder Singh Brar

rtc have different i2c client than power(pmic) block. So rtc device should sit under its own i2c client in device hierarchy, which

reflects in sysfs also.

Quoted 1 line

This patch modifies code to register rtc cell with rtc->dev as

parent.

Quoted 7 lines

Without this patch :

# ls /sys/class/i2c-adapter/i2c-0/0-0009/
driver         max77686-pmic  modalias       power          uevent
max77686-clk   max77686-rtc   name           subsystem

After applying patch :

Quoted 8 lines
# ls /sys/class/i2c-adapter/i2c-0/0-0006/
driver/        modalias       power/         uevent
max77686-rtc/  name           subsystem/

---

Or Can we follow another (exhaustive but more cleaner) approach,

which

Quoted 7 lines

will be more like code refactoring and cleanup rather than only fix:
Since rtc uses i2c client, which gets created using i2c_new_dummy() and is not shared by any other cell of max77686. So we can covert rtc platform driver itself to i2c client driver. It will also allow to expilicitly describe max77686-rtc in DT which we can't do now. It can be applicable to some other existing and new mfd pmic drivers. Any suggestion/comments ?

Quoted 4 lines

Hi,

What kind of problem is solved by this patch?

Let me try to explain once again :)
After seeing a message "i2c i2c-0: .... , addr=0x06, .." in dmesg log, I was not able to find any such device in sysfs as well as device tree. There was no device under /sys/class/i2c-dev/i2c-0/device/0-0006/ Isn't something wrong or missing ?

This patch fixes that missing parent child relation, which IMO should be correct always, though it causes any major problem or not.

Still I am thinking, 0-0006 slave device(rtc) shouldn't also appear in DT? As DT should describe the hardware that we are using.

Warm regards,
Yadwinder

Quoted 71 lines

Best regards,
Krzysztof

drivers/mfd/max77686.c static int max77686_i2c_probe(struct i2c_client

Quoted 25 lines
---
 drivers/mfd/max77686.c |   22 ++++++++++++++++++++--
 1 files changed, 20 insertions(+), 2 deletions(-)
drivers/mfd/max77686.c index renamed from drivers/mfd/max77686.c +0 -0

929795e..22c0948 100644

drivers/mfd/max77686.c +4 -1
@@ -39,10 +39,13 @@
 
 static const struct mfd_cell max77686_devs[] = {
 	{ .name = "max77686-pmic", },
-	{ .name = "max77686-rtc", },
 	{ .name = "max77686-clk", },
 };
 
+static const struct mfd_cell max77686_rtc_dev[] = {
+	{ .name = "max77686-rtc", },
+};
+
 static const struct mfd_cell max77802_devs[] = {
 	{ .name = "max77802-pmic", },
 	{ .name = "max77802-clk", },
@@ -332,14 +335,27 @@ static int max77686_i2c_probe(struct i2c_client

*i2c,

drivers/mfd/max77686.c static int max77686_i2c_probe(struct i2c_client *i2c,

Quoted 5 lines
drivers/mfd/max77686.c +2 -0
 		goto err_del_irqc;
 	}
 
+	if (max77686->type == TYPE_MAX77686) {
+		ret = mfd_add_devices(&max77686->rtc->dev, -1,

max77686_rtc_dev,

drivers/mfd/max77686.c static int max77686_i2c_probe(struct i2c_client *i2c,

Quoted 9 lines
drivers/mfd/max77686.c +8 -0
+			1, NULL, 0, NULL);
+		if (ret < 0) {
+			dev_err(&max77686->rtc->dev,
+				"failed to add RTC device %d\n", ret);
+			goto err_del_rtc_irqc;
+		}
+	}
+
 	ret = mfd_add_devices(max77686->dev, -1, cells, n_devs, NULL, 0,

NULL);

drivers/mfd/max77686.c static int max77686_i2c_remove(struct i2c_client

Quoted 15 lines
drivers/mfd/max77686.c +4 -1
 	if (ret < 0) {
 		dev_err(&i2c->dev, "failed to add MFD devices: %d\n", ret);
-		goto err_del_rtc_irqc;
+		goto err_del_rtc_dev;
 	}
 
 	return 0;
 
+err_del_rtc_dev:
+	if (max77686->type == TYPE_MAX77686)
+		mfd_remove_devices(&max77686->rtc->dev);
 err_del_rtc_irqc:
 	regmap_del_irq_chip(max77686->irq, max77686->rtc_irq_data);
 err_del_irqc:
@@ -356,6 +372,8 @@ static int max77686_i2c_remove(struct i2c_client

*i2c)

Quoted 9 lines
drivers/mfd/max77686.c +2 -0
 	struct max77686_dev *max77686 = i2c_get_clientdata(i2c);
 
 	mfd_remove_devices(max77686->dev);
+	if (max77686->type == TYPE_MAX77686)
+		mfd_remove_devices(&max77686->rtc->dev);
 
 	regmap_del_irq_chip(max77686->irq, max77686->rtc_irq_data);
 	regmap_del_irq_chip(max77686->irq, max77686->irq_data);
#4 lore raw

PATCH 1/1 mfd: max77686: Fix parent of rtc device

Quoted 37 lines · Yadwinder Singh Brar
Quoted 30 lines · Krzysztof Koz?owski
Quoted 2 lines · Yadwinder Singh Brar

rtc have different i2c client than power(pmic) block. So rtc device should sit under its own i2c client in device hierarchy, which

reflects in sysfs also.

Quoted 1 line

This patch modifies code to register rtc cell with rtc->dev as

parent.

Quoted 7 lines

Without this patch :

# ls /sys/class/i2c-adapter/i2c-0/0-0009/
driver         max77686-pmic  modalias       power          uevent
max77686-clk   max77686-rtc   name           subsystem

After applying patch :

Quoted 8 lines
# ls /sys/class/i2c-adapter/i2c-0/0-0006/
driver/        modalias       power/         uevent
max77686-rtc/  name           subsystem/

---

Or Can we follow another (exhaustive but more cleaner) approach,

which

Quoted 7 lines

will be more like code refactoring and cleanup rather than only fix:
Since rtc uses i2c client, which gets created using i2c_new_dummy() and is not shared by any other cell of max77686. So we can covert rtc platform driver itself to i2c client driver. It will also allow to expilicitly describe max77686-rtc in DT which we can't do now. It can be applicable to some other existing and new mfd pmic drivers. Any suggestion/comments ?

Quoted 4 lines

Hi,

What kind of problem is solved by this patch?

Quoted 8 lines

Let me try to explain once again :)
After seeing a message "i2c i2c-0: .... , addr=0x06, .." in dmesg log, I was not able to find any such device in sysfs as well as device tree. There was no device under /sys/class/i2c-dev/i2c-0/device/0-0006/ Isn't something wrong or missing ?

This patch fixes that missing parent child relation, which IMO should be correct always, though it causes any major problem or not.

OK, I got your point. I'm fine with both solutions and the patch looks good, so:

Quoted 2 lines

Still I am thinking, 0-0006 slave device(rtc) shouldn't also appear in DT? As DT should describe the hardware that we are using.

Your patch properly describes the hardware. However from driver perspective, the RTC here is not an standalone driver and depends on parent (MFD) driver.

Although max77686 RTC could have its own DeviceTree node, I think it should still be put under main MFD driver's node, because the parent manages stuff like interrupts.

Best regards,
Krzysztof

#5 lore raw

PATCH 1/1 mfd: max77686: Fix parent of rtc device

Quoted 52 lines · Krzysztof Kozlowski
Quoted 6 lines · Yadwinder Singh Brar
Quoted 4 lines · Krzysztof Kozłowski
Quoted 3 lines · Yadwinder Singh Brar

rtc have different i2c client than power(pmic) block. So rtc device should sit under its own i2c client in device hierarchy, which

Quoted 7 lines
Quoted 7 lines

reflects in sysfs also.

Quoted 1 line

This patch modifies code to register rtc cell with rtc->dev as

parent.

Quoted 4 lines

Without this patch :

# ls /sys/class/i2c-adapter/i2c-0/0-0009/
driver         max77686-pmic  modalias       power

uevent

Quoted 7 lines
Quoted 7 lines
Quoted 7 lines

max77686-clk max77686-rtc name subsystem

After applying patch :

# ls /sys/class/i2c-adapter/i2c-0/0-0006/
driver/        modalias       power/         uevent
max77686-rtc/  name           subsystem/
Quoted 6 lines
Quoted 6 lines
Quoted 4 lines

---

Or Can we follow another (exhaustive but more cleaner) approach,

which

Quoted 1 line

will be more like code refactoring and cleanup rather than only

fix:

Quoted 4 lines
Quoted 4 lines
Quoted 4 lines

Since rtc uses i2c client, which gets created using i2c_new_dummy() and is not shared by any other cell of max77686. So we can covert rtc platform driver itself to i2c client driver. It will also allow to expilicitly describe max77686-rtc in DT

which we can't do now.

Quoted 1 line
Quoted 1 line
Quoted 1 line

It can be applicable to some other existing and new mfd pmic

drivers.

Quoted 9 lines
Quoted 6 lines
Quoted 1 line

Any suggestion/comments ?

Hi,

What kind of problem is solved by this patch?

Let me try to explain once again :)
After seeing a message "i2c i2c-0: .... , addr=0x06, .." in dmesg

log,

Quoted 1 line

I was not able to find any such device in sysfs as well as device

tree.

Quoted 3 lines

There was no device under /sys/class/i2c-dev/i2c-0/device/0-0006/ Isn't something wrong or missing ?

Quoted 7 lines
Quoted 2 lines

This patch fixes that missing parent child relation, which IMO should be correct always, though it causes any major problem or not.

OK, I got your point. I'm fine with both solutions and the patch looks good, so:

Thanks for reviewing :).

Quoted 8 lines
Quoted 1 line

Still I am thinking, 0-0006 slave device(rtc) shouldn't also appear

in DT?

Quoted 1 line

As DT should describe the hardware that we are using.

Your patch properly describes the hardware. However from driver perspective, the RTC here is not an standalone driver and depends on parent (MFD) driver.

Hmm ... I can't see any hard dependency. I think rtc can survive as independent i2c device. And rtc(@06) is more like a sibling of existing MFD driver(max77686@09)

Quoted 4 lines

Although max77686 RTC could have its own DeviceTree node, I think it should still be put under main MFD driver's node, because the parent manages stuff like interrupts.

I think it will not sound good to have something like max77686-rtc@06 node under max77686@09 node, since both are kind of siblings. And interrupts should not be a restricting factor, In case of max77686 interrupt source and mask registers for rtc also lie in rtc i2c register bank so we can add an irq_chip from rtc driver itself.

Only thing I can see which can be little bit tricky, is providing alarm->pending info(pending interrupt) in alarm_read() callback in rtc as currently its based on MAX77686_REG_STATUS2 which is only common register in power(pmic) register bank of max77686. Though in practical scenarios it may not be non zero, since reading once source register clears this status also, but we may have to keep it for sake of functionality completeness.

I can’t see any way(something similar to syscon) for sharing i2c regmap between independent drivers, other than getting reference to regmap from i2c device found by of_find_i2c_device_by_node(). Anyone can suggest better idea?

Best Regards,
Yadwinder