[PATCHv4] mfd: cpcap: implement irq sense helper
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Message ID 20170324084240.23251-1-sre@kernel.org
State New, archived
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Series
  • [PATCHv4] mfd: cpcap: implement irq sense helper
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Commit Message

Sebastian Reichel March 24, 2017, 8:42 a.m. UTC
CPCAP can sense if IRQ is currently set or not. This
functionality is required for a few subdevices, such
as the power button and usb phy modules.

Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>

---
Hi Lee,

I hope this is fine with you. I tried to come up
with a sensible macro for reg, but everything I
came up with actually reduced readability.

-- Sebastian

Changes since PATCHv3:
 - add explicit extern to function definition
 - use BIT macro for mask variable
 - avoid magic numbers
---
 drivers/mfd/motorola-cpcap.c       | 28 ++++++++++++++++++++++++++++
 include/linux/mfd/motorola-cpcap.h |  2 ++
 2 files changed, 30 insertions(+)

Comments

Lee Jones March 28, 2017, 10:27 a.m. UTC | #1
On Fri, 24 Mar 2017, Sebastian Reichel wrote:

> CPCAP can sense if IRQ is currently set or not. This
> functionality is required for a few subdevices, such
> as the power button and usb phy modules.
> 
> Acked-by: Tony Lindgren <tony@atomide.com>
> Signed-off-by: Sebastian Reichel <sre@kernel.org>
> 
> ---
> Hi Lee,
> 
> I hope this is fine with you. I tried to come up
> with a sensible macro for reg, but everything I
> came up with actually reduced readability.
> 
> -- Sebastian
> 
> Changes since PATCHv3:
>  - add explicit extern to function definition
>  - use BIT macro for mask variable
>  - avoid magic numbers
> ---
>  drivers/mfd/motorola-cpcap.c       | 28 ++++++++++++++++++++++++++++
>  include/linux/mfd/motorola-cpcap.h |  2 ++
>  2 files changed, 30 insertions(+)
> 
> diff --git a/drivers/mfd/motorola-cpcap.c b/drivers/mfd/motorola-cpcap.c
> index 6aeada7d7ce5..c80997a377a1 100644
> --- a/drivers/mfd/motorola-cpcap.c
> +++ b/drivers/mfd/motorola-cpcap.c
> @@ -23,6 +23,8 @@
>  
>  #define CPCAP_NR_IRQ_REG_BANKS	6
>  #define CPCAP_NR_IRQ_CHIPS	3
> +#define CPCAP_REGISTER_SIZE 4
> +#define CPCAP_REGISTER_BITS 16
>  
>  struct cpcap_ddata {
>  	struct spi_device *spi;
> @@ -32,6 +34,32 @@ struct cpcap_ddata {
>  	struct regmap *regmap;
>  };
>  
> +static int cpcap_sense_irq(struct regmap *regmap, int irq)
> +{
> +	int regnum = irq / CPCAP_REGISTER_BITS;
> +	int mask = BIT(irq % CPCAP_REGISTER_BITS);
> +	int reg = CPCAP_REG_INTS1 + (regnum * CPCAP_REGISTER_SIZE);
> +	int err, val;
> +
> +	if (reg < CPCAP_REG_INTS1 || reg > CPCAP_REG_INTS4)
> +		return -EINVAL;
> +
> +	err = regmap_read(regmap, reg, &val);
> +	if (err)
> +		return err;
> +
> +	return !!(val & mask);
> +}
> +
> +int cpcap_sense_virq(struct regmap *regmap, int virq)
> +{
> +	struct regmap_irq_chip_data *d = irq_get_chip_data(virq);
> +	int base = regmap_irq_chip_get_base(d);

What base is this?  Could it be used to avoid some calculations in
cpcap_sense_irq()?

> +	return cpcap_sense_irq(regmap, virq - base);
> +}
> +EXPORT_SYMBOL_GPL(cpcap_sense_virq);
> +
>  static int cpcap_check_revision(struct cpcap_ddata *cpcap)
>  {
>  	u16 vendor, rev;
> diff --git a/include/linux/mfd/motorola-cpcap.h b/include/linux/mfd/motorola-cpcap.h
> index b4031c2b2214..793aa695faa0 100644
> --- a/include/linux/mfd/motorola-cpcap.h
> +++ b/include/linux/mfd/motorola-cpcap.h
> @@ -290,3 +290,5 @@ static inline int cpcap_get_vendor(struct device *dev,
>  
>  	return 0;
>  }
> +
> +extern int cpcap_sense_virq(struct regmap *regmap, int virq);
Sebastian Reichel March 28, 2017, 2:54 p.m. UTC | #2
Hi Lee,

On Tue, Mar 28, 2017 at 11:27:16AM +0100, Lee Jones wrote:
> > +int cpcap_sense_virq(struct regmap *regmap, int virq)
> > +{
> > +	struct regmap_irq_chip_data *d = irq_get_chip_data(virq);
> > +	int base = regmap_irq_chip_get_base(d);
> 
> What base is this?

This function takes an Linux irq number. That number is a virtual
irq number, which has nothing to do with the hardware. For example
a platform could look like this:

linux irq   device          base   device irq
---------------------------------------------
0-63        SoC             0      0-63
64-127      SoC-GPIO        64     0-63
128-191     CPCAP           128    0-63

For the above example the function would map 128-191 to 0-63 as
used by the device.

> Could it be used to avoid some calculations in cpcap_sense_irq()?

No.

> > +	return cpcap_sense_irq(regmap, virq - base);
> > +}
> > +EXPORT_SYMBOL_GPL(cpcap_sense_virq);

-- Sebastian
Lee Jones March 29, 2017, 8:04 a.m. UTC | #3
On Tue, 28 Mar 2017, Sebastian Reichel wrote:

> Hi Lee,
> 
> On Tue, Mar 28, 2017 at 11:27:16AM +0100, Lee Jones wrote:
> > > +int cpcap_sense_virq(struct regmap *regmap, int virq)
> > > +{
> > > +	struct regmap_irq_chip_data *d = irq_get_chip_data(virq);
> > > +	int base = regmap_irq_chip_get_base(d);
> > 
> > What base is this?
> 
> This function takes an Linux irq number. That number is a virtual
> irq number, which has nothing to do with the hardware. For example
> a platform could look like this:
> 
> linux irq   device          base   device irq
> ---------------------------------------------
> 0-63        SoC             0      0-63
> 64-127      SoC-GPIO        64     0-63
> 128-191     CPCAP           128    0-63
> 
> For the above example the function would map 128-191 to 0-63 as
> used by the device.

In which case may I suggest that you rename the variable, since 'base'
is commonly used in the kernel to mean base of a particular IP's
memory block.

> > Could it be used to avoid some calculations in cpcap_sense_irq()?
> 
> No.
> 
> > > +	return cpcap_sense_irq(regmap, virq - base);
> > > +}
> > > +EXPORT_SYMBOL_GPL(cpcap_sense_virq);
> 
> -- Sebastian

Patch
diff mbox series

diff --git a/drivers/mfd/motorola-cpcap.c b/drivers/mfd/motorola-cpcap.c
index 6aeada7d7ce5..c80997a377a1 100644
--- a/drivers/mfd/motorola-cpcap.c
+++ b/drivers/mfd/motorola-cpcap.c
@@ -23,6 +23,8 @@ 
 
 #define CPCAP_NR_IRQ_REG_BANKS	6
 #define CPCAP_NR_IRQ_CHIPS	3
+#define CPCAP_REGISTER_SIZE 4
+#define CPCAP_REGISTER_BITS 16
 
 struct cpcap_ddata {
 	struct spi_device *spi;
@@ -32,6 +34,32 @@  struct cpcap_ddata {
 	struct regmap *regmap;
 };
 
+static int cpcap_sense_irq(struct regmap *regmap, int irq)
+{
+	int regnum = irq / CPCAP_REGISTER_BITS;
+	int mask = BIT(irq % CPCAP_REGISTER_BITS);
+	int reg = CPCAP_REG_INTS1 + (regnum * CPCAP_REGISTER_SIZE);
+	int err, val;
+
+	if (reg < CPCAP_REG_INTS1 || reg > CPCAP_REG_INTS4)
+		return -EINVAL;
+
+	err = regmap_read(regmap, reg, &val);
+	if (err)
+		return err;
+
+	return !!(val & mask);
+}
+
+int cpcap_sense_virq(struct regmap *regmap, int virq)
+{
+	struct regmap_irq_chip_data *d = irq_get_chip_data(virq);
+	int base = regmap_irq_chip_get_base(d);
+
+	return cpcap_sense_irq(regmap, virq - base);
+}
+EXPORT_SYMBOL_GPL(cpcap_sense_virq);
+
 static int cpcap_check_revision(struct cpcap_ddata *cpcap)
 {
 	u16 vendor, rev;
diff --git a/include/linux/mfd/motorola-cpcap.h b/include/linux/mfd/motorola-cpcap.h
index b4031c2b2214..793aa695faa0 100644
--- a/include/linux/mfd/motorola-cpcap.h
+++ b/include/linux/mfd/motorola-cpcap.h
@@ -290,3 +290,5 @@  static inline int cpcap_get_vendor(struct device *dev,
 
 	return 0;
 }
+
+extern int cpcap_sense_virq(struct regmap *regmap, int virq);