Re: [PATCH v3 3/6] mfd: rn5t618: add irq support

[Andreas Kemnade <andreas@kemnade.info>]

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On Tue, 10 Dec 2019 09:32:25 +0000
Lee Jones <lee.jones@linaro.org> wrote:

> On Fri, 29 Nov 2019, Andreas Kemnade wrote:
> 
> > This adds support for irq handling in the rc5t619 which is required  
> 
> Please capitalise abbreviations and device names (as they do in the
> datasheet).
> 
for IRQ vs. irq: I see both things in commit messages. Is there any rule about
that?

> > for properly implementing subdevices like rtc.  
> 
> "RTC"
> 
> > For now only definitions for the variant rc5t619 are included.
> > 
> > Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
> > ---
> > Changes in v3:
> > alignment cleanup
> > 
> > Changes in v2:
> > - no dead code, did some more testing and thinking for that
> > - remove extra empty lines
> > 
> >  drivers/mfd/Kconfig         |  1 +
> >  drivers/mfd/Makefile        |  2 +-
> >  drivers/mfd/rn5t618-core.c  | 34 ++++++++++++++-
> >  drivers/mfd/rn5t618-irq.c   | 85 +++++++++++++++++++++++++++++++++++++
> >  include/linux/mfd/rn5t618.h | 16 +++++++
> >  5 files changed, 136 insertions(+), 2 deletions(-)
> >  create mode 100644 drivers/mfd/rn5t618-irq.c
> > 
> > diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> > index ae24d3ea68ea..522e068d0082 100644
> > --- a/drivers/mfd/Kconfig
> > +++ b/drivers/mfd/Kconfig
> > @@ -1057,6 +1057,7 @@ config MFD_RN5T618
> >  	depends on OF
> >  	select MFD_CORE
> >  	select REGMAP_I2C
> > +	select REGMAP_IRQ
> >  	help
> >  	  Say yes here to add support for the Ricoh RN5T567,
> >  	  RN5T618, RC5T619 PMIC.
> > diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> > index 110ea700231b..2906d5db67d0 100644
> > --- a/drivers/mfd/Makefile
> > +++ b/drivers/mfd/Makefile
> > @@ -217,7 +217,7 @@ obj-$(CONFIG_MFD_VIPERBOARD)    += viperboard.o
> >  obj-$(CONFIG_MFD_RC5T583)	+= rc5t583.o rc5t583-irq.o
> >  obj-$(CONFIG_MFD_RK808)		+= rk808.o
> >  
> > -rn5t618-objs			:= rn5t618-core.o
> > +rn5t618-objs			:= rn5t618-core.o rn5t618-irq.o
> >  obj-$(CONFIG_MFD_RN5T618)	+= rn5t618.o
> >  obj-$(CONFIG_MFD_SEC_CORE)	+= sec-core.o sec-irq.o
> >  obj-$(CONFIG_MFD_SYSCON)	+= syscon.o
> > diff --git a/drivers/mfd/rn5t618-core.c b/drivers/mfd/rn5t618-core.c
> > index da5cd9c92a59..1e2326217681 100644
> > --- a/drivers/mfd/rn5t618-core.c
> > +++ b/drivers/mfd/rn5t618-core.c
> > @@ -8,6 +8,7 @@
> >  
> >  #include <linux/delay.h>
> >  #include <linux/i2c.h>
> > +#include <linux/interrupt.h>
> >  #include <linux/mfd/core.h>
> >  #include <linux/mfd/rn5t618.h>
> >  #include <linux/module.h>
> > @@ -105,7 +106,8 @@ static int rn5t618_i2c_probe(struct i2c_client *i2c,
> >  
> >  	i2c_set_clientdata(i2c, priv);
> >  	priv->variant = (long)of_id->data;
> > -
> > +	priv->chip_irq = i2c->irq;
> > +	priv->dev = &i2c->dev;  
> 
> '\n'
> 
> >  	priv->regmap = devm_regmap_init_i2c(i2c, &rn5t618_regmap_config);
> >  	if (IS_ERR(priv->regmap)) {
> >  		ret = PTR_ERR(priv->regmap);
> > @@ -137,6 +139,11 @@ static int rn5t618_i2c_probe(struct i2c_client *i2c,
> >  		return ret;
> >  	}
> >  
> > +	if (priv->chip_irq > 0) {
> > +		if (rn5t618_irq_init(priv))
> > +			priv->chip_irq = 0;
> > +	}
> > +
> >  	return 0;
> >  }
> >  
> > @@ -154,15 +161,40 @@ static int rn5t618_i2c_remove(struct i2c_client *i2c)
> >  	return 0;
> >  }
> >  
> > +static int __maybe_unused rn5t618_i2c_suspend(struct device *dev)
> > +{
> > +	struct rn5t618 *priv = dev_get_drvdata(dev);
> > +
> > +	if (priv->chip_irq)
> > +		disable_irq(priv->chip_irq);
> > +
> > +	return 0;
> > +}
> > +
> > +static int __maybe_unused rn5t618_i2c_resume(struct device *dev)
> > +{
> > +	struct rn5t618 *priv = dev_get_drvdata(dev);
> > +
> > +	if (priv->chip_irq)
> > +		enable_irq(priv->chip_irq);
> > +
> > +	return 0;
> > +}
> > +
> >  static const struct i2c_device_id rn5t618_i2c_id[] = {
> >  	{ }
> >  };
> >  MODULE_DEVICE_TABLE(i2c, rn5t618_i2c_id);  
> 
> Not this patch I know, but it's strange to see this empty.
>

Yes, should be cleaned up. For now the device tree stuff seems to kick in.
 
> > +static SIMPLE_DEV_PM_OPS(rn5t618_i2c_dev_pm_ops,
> > +			rn5t618_i2c_suspend,
> > +			rn5t618_i2c_resume);
> > +
> >  static struct i2c_driver rn5t618_i2c_driver = {
> >  	.driver = {
> >  		.name = "rn5t618",
> >  		.of_match_table = of_match_ptr(rn5t618_of_match),
> > +		.pm = &rn5t618_i2c_dev_pm_ops,
> >  	},
> >  	.probe = rn5t618_i2c_probe,
> >  	.remove = rn5t618_i2c_remove,
> > diff --git a/drivers/mfd/rn5t618-irq.c b/drivers/mfd/rn5t618-irq.c  
> 
> Why does this need to be separate from the core file?
> 
It does not need. It is not that complex. There will just be another set of
tables for the rn5t618

> > new file mode 100644
> > index 000000000000..8a4c56429768
> > --- /dev/null
> > +++ b/drivers/mfd/rn5t618-irq.c
> > @@ -0,0 +1,85 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +/*
> > + * Copyright 2019 Andreas Kemnade
> > + */
> > +#include <linux/device.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/irq.h>
> > +#include <linux/module.h>
> > +#include <linux/regmap.h>
> > +
> > +#include <linux/mfd/rn5t618.h>
> > +
> > +static const struct regmap_irq rc5t619_irqs[] = {
> > +	[RN5T618_IRQ_SYS] = {
> > +		.reg_offset = 0,
> > +		.mask = (0 << 1)
> > +	},
> > +	[RN5T618_IRQ_DCDC] = {
> > +		.reg_offset = 0,
> > +		.mask = (1 << 1)  
> 
> BIT()
> 
yes, makes things more readable.

> > +	},
> > +	[RN5T618_IRQ_RTC]  = {
> > +		.reg_offset = 0,
> > +		.mask = (1 << 2)
> > +	},
> > +	[RN5T618_IRQ_ADC] = {
> > +		.reg_offset = 0,
> > +		.mask = (1 << 3)
> > +	},
> > +	[RN5T618_IRQ_GPIO] = {
> > +		.reg_offset = 0,
> > +		.mask = (1 << 4)
> > +	},
> > +	[RN5T618_IRQ_CHG] = {
> > +		.reg_offset = 0,
> > +		.mask = (1 << 6),
> > +	}
> > +};  
> 
> There are probably macros available to tidy this up.
> 
> Take a look in include/linux/regmap.h
> 
I will have a look.

> > +static const struct regmap_irq_chip rc5t619_irq_chip = {
> > +	.name = "rc5t619",
> > +	.irqs = rc5t619_irqs,
> > +	.num_irqs = ARRAY_SIZE(rc5t619_irqs),
> > +	.num_regs = 1,
> > +	.status_base = RN5T618_INTMON,
> > +	.mask_base = RN5T618_INTEN,
> > +	.mask_invert = true,
> > +};
> > +
> > +int rn5t618_irq_init(struct rn5t618 *rn5t618)
> > +{
> > +	const struct regmap_irq_chip *irq_chip;
> > +	int ret;
> > +
> > +	if (!rn5t618->chip_irq)
> > +		return 0;
> > +
> > +	switch (rn5t618->variant) {
> > +	case RC5T619:
> > +		irq_chip = &rc5t619_irq_chip;
> > +		break;
> > +
> > +		/* TODO: check irq definitions for other variants */  
> 
> No need for this.  It's implied.
> 
> OOI, when support for more variants be added?
> 
I have done research about the RN5T618. It has just the RTC IRQ missing, I could just
add the table for it to prepare the path for others. I cannot test it but
since there are no users yet, it does not harm that it is not well-tested.

No idea about the RN5T567.

> > +	default:
> > +		irq_chip = NULL;
> > +		break;
> > +	}
> > +
> > +	if (!irq_chip) {
> > +		dev_err(rn5t618->dev, "no IRQ definition known for variant\n");  
> 
> How about '"Variant %d not currently supported", rn5t618->variant'
> 
makes sense.

> > +		return -ENOENT;
> > +	}
> > +
> > +	ret = devm_regmap_add_irq_chip(rn5t618->dev, rn5t618->regmap,
> > +				       rn5t618->chip_irq,
> > +				       IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
> > +				       0, irq_chip, &rn5t618->irq_data);
> > +	if (ret != 0) {  
> 
> if (ret)
> 
> > +		dev_err(rn5t618->dev, "Failed to register IRQ chip\n");
> > +		return ret;
> > +	}
> > +
> > +	return 0;
> > +}
> > diff --git a/include/linux/mfd/rn5t618.h b/include/linux/mfd/rn5t618.h
> > index d62ef48060b5..edd2b6485e3b 100644
> > --- a/include/linux/mfd/rn5t618.h
> > +++ b/include/linux/mfd/rn5t618.h
> > @@ -242,9 +242,25 @@ enum {
> >  	RC5T619,
> >  };
> >  
> > +/* RN5T618 IRQ definitions */
> > +enum {
> > +	RN5T618_IRQ_SYS,  
> 
> = 0?
> 
> > +	RN5T618_IRQ_DCDC,
> > +	RN5T618_IRQ_RTC,
> > +	RN5T618_IRQ_ADC,
> > +	RN5T618_IRQ_GPIO,
> > +	RN5T618_IRQ_CHG,
> > +	RN5T618_NR_IRQS,
> > +};
> > +
> >  struct rn5t618 {
> >  	struct regmap *regmap;
> > +	struct device *dev;
> >  	long variant;
> > +
> > +	int chip_irq;  
> 
> Are there any other kinds of IRQ?
> 
there is some separate battery low input for the charger which
could be modeled as an IRQ.
But that could be handled entirely there when I am at it and
in the corresponding subdevice. 

Regards,
Andreas

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