2012-10-30 18:13:55

by Pantelis Antoniou

[permalink] [raw]
Subject: [PATCH] ti_tscadc: Match mfd sub devices to regmap interface

The MFD parent device now uses a regmap, instead of direct
memory access. Use the same method in the sub devices to avoid
nasty surprises.

Also rework the channel initialization of tiadc a bit.

Signed-off-by: Pantelis Antoniou <[email protected]>
---
drivers/iio/adc/ti_am335x_adc.c | 27 +++++++++++++++++++--------
drivers/input/touchscreen/ti_am335x_tsc.c | 16 +++++++++++++---
drivers/mfd/ti_am335x_tscadc.c | 7 +++++--
3 files changed, 37 insertions(+), 13 deletions(-)

diff --git a/drivers/iio/adc/ti_am335x_adc.c b/drivers/iio/adc/ti_am335x_adc.c
index d48fd79..5f325c1 100644
--- a/drivers/iio/adc/ti_am335x_adc.c
+++ b/drivers/iio/adc/ti_am335x_adc.c
@@ -23,7 +23,9 @@
#include <linux/iio/iio.h>
#include <linux/iio/machine.h>
#include <linux/iio/driver.h>
+#include <linux/regmap.h>

+#include <linux/io.h>
#include <linux/mfd/ti_am335x_tscadc.h>
#include <linux/platform_data/ti_am335x_adc.h>

@@ -36,13 +38,17 @@ struct tiadc_device {

static unsigned int tiadc_readl(struct tiadc_device *adc, unsigned int reg)
{
- return readl(adc->mfd_tscadc->tscadc_base + reg);
+ unsigned int val;
+
+ val = (unsigned int)-1;
+ regmap_read(adc->mfd_tscadc->regmap_tscadc, reg, &val);
+ return val;
}

static void tiadc_writel(struct tiadc_device *adc, unsigned int reg,
unsigned int val)
{
- writel(val, adc->mfd_tscadc->tscadc_base + reg);
+ regmap_write(adc->mfd_tscadc->regmap_tscadc, reg, val);
}

static void tiadc_step_config(struct tiadc_device *adc_dev)
@@ -75,22 +81,24 @@ static void tiadc_step_config(struct tiadc_device *adc_dev)
tiadc_writel(adc_dev, REG_SE, STPENB_STEPENB);
}

-static int tiadc_channel_init(struct iio_dev *indio_dev, int channels)
+static int tiadc_channel_init(struct iio_dev *indio_dev,
+ struct tiadc_device *adc_dev)
{
struct iio_chan_spec *chan_array;
struct iio_chan_spec *chan;
char *s;
int i, len, size, ret;
+ int channels = adc_dev->channels;

- size = indio_dev->num_channels * (sizeof(struct iio_chan_spec) + 6);
+ size = channels * (sizeof(struct iio_chan_spec) + 6);
chan_array = kzalloc(size, GFP_KERNEL);
if (chan_array == NULL)
return -ENOMEM;

/* buffer space is after the array */
- s = (char *)(chan_array + indio_dev->num_channels);
+ s = (char *)(chan_array + channels);
chan = chan_array;
- for (i = 0; i < indio_dev->num_channels; i++, chan++, s += len + 1) {
+ for (i = 0; i < channels; i++, chan++, s += len + 1) {

len = sprintf(s, "AIN%d", i);

@@ -105,8 +113,9 @@ static int tiadc_channel_init(struct iio_dev *indio_dev, int channels)
}

indio_dev->channels = chan_array;
+ indio_dev->num_channels = channels;

- size = (indio_dev->num_channels + 1) * sizeof(struct iio_map);
+ size = (channels + 1) * sizeof(struct iio_map);
adc_dev->map = kzalloc(size, GFP_KERNEL);
if (adc_dev->map == NULL) {
kfree(chan_array);
@@ -203,7 +212,7 @@ static int __devinit tiadc_probe(struct platform_device *pdev)

tiadc_step_config(adc_dev);

- err = tiadc_channel_init(indio_dev, adc_dev->channels);
+ err = tiadc_channel_init(indio_dev, adc_dev);
if (err < 0)
goto err_free_device;

@@ -213,6 +222,8 @@ static int __devinit tiadc_probe(struct platform_device *pdev)

platform_set_drvdata(pdev, indio_dev);

+ dev_info(&pdev->dev, "Initialized\n");
+
return 0;

err_free_channels:
diff --git a/drivers/input/touchscreen/ti_am335x_tsc.c b/drivers/input/touchscreen/ti_am335x_tsc.c
index 7a26810..d09e1a7 100644
--- a/drivers/input/touchscreen/ti_am335x_tsc.c
+++ b/drivers/input/touchscreen/ti_am335x_tsc.c
@@ -26,6 +26,7 @@
#include <linux/io.h>
#include <linux/input/ti_am335x_tsc.h>
#include <linux/delay.h>
+#include <linux/regmap.h>

#include <linux/mfd/ti_am335x_tscadc.h>

@@ -64,13 +65,17 @@ struct titsc {

static unsigned int titsc_readl(struct titsc *ts, unsigned int reg)
{
- return readl(ts->mfd_tscadc->tscadc_base + reg);
+ unsigned int val;
+
+ val = (unsigned int)-1;
+ regmap_read(ts->mfd_tscadc->regmap_tscadc, reg, &val);
+ return val;
}

static void titsc_writel(struct titsc *tsc, unsigned int reg,
unsigned int val)
{
- writel(val, tsc->mfd_tscadc->tscadc_base + reg);
+ regmap_write(tsc->mfd_tscadc->regmap_tscadc, reg, val);
}

/*
@@ -455,10 +460,15 @@ static int __devinit titsc_probe(struct platform_device *pdev)

/* register to the input system */
err = input_register_device(input_dev);
- if (err)
+ if (err) {
+ dev_err(&pdev->dev, "Failed to register input device\n");
goto err_free_irq;
+ }

platform_set_drvdata(pdev, ts_dev);
+
+ dev_info(&pdev->dev, "Initialized OK\n");
+
return 0;

err_free_irq:
diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c
index cbb8b70c..4a7041c 100644
--- a/drivers/mfd/ti_am335x_tscadc.c
+++ b/drivers/mfd/ti_am335x_tscadc.c
@@ -31,6 +31,7 @@ static unsigned int tscadc_readl(struct ti_tscadc_dev *tsadc, unsigned int reg)
{
unsigned int val;

+ val = (unsigned int)-1;
regmap_read(tsadc->regmap_tscadc, reg, &val);
return val;
}
@@ -68,7 +69,7 @@ static int __devinit ti_tscadc_probe(struct platform_device *pdev)
int irq;
int err, ctrl;
int clk_value, clock_rate;
- int tsc_wires, adc_channels = 0, total_channels;
+ int tsc_wires = 0, adc_channels = 0, total_channels;

if (!pdata) {
dev_err(&pdev->dev, "Could not find platform data\n");
@@ -78,7 +79,9 @@ static int __devinit ti_tscadc_probe(struct platform_device *pdev)
if (pdata->adc_init)
adc_channels = pdata->adc_init->adc_channels;

- tsc_wires = pdata->tsc_init->wires;
+ if (pdata->tsc_init)
+ tsc_wires = pdata->tsc_init->wires;
+
total_channels = tsc_wires + adc_channels;

if (total_channels > 8) {
--
1.7.12


2012-10-30 18:21:39

by Lars-Peter Clausen

[permalink] [raw]
Subject: Re: [PATCH] ti_tscadc: Match mfd sub devices to regmap interface

On 10/31/2012 04:55 PM, Pantelis Antoniou wrote:
> The MFD parent device now uses a regmap, instead of direct
> memory access. Use the same method in the sub devices to avoid
> nasty surprises.
>
> Also rework the channel initialization of tiadc a bit.

Those two bits are not even closely related, they should really go into
separate patches.

>
> Signed-off-by: Pantelis Antoniou <[email protected]>
> ---
> drivers/iio/adc/ti_am335x_adc.c | 27 +++++++++++++++++++--------
> drivers/input/touchscreen/ti_am335x_tsc.c | 16 +++++++++++++---
> drivers/mfd/ti_am335x_tscadc.c | 7 +++++--
> 3 files changed, 37 insertions(+), 13 deletions(-)
>
[...]
>
> @@ -213,6 +222,8 @@ static int __devinit tiadc_probe(struct platform_device *pdev)
>
> platform_set_drvdata(pdev, indio_dev);
>
> + dev_info(&pdev->dev, "Initialized\n");

That's just noise, please don't add it. Imagine every driver did this you'd
end up with a lot of noise your debug log.

> +
> return 0;
>
> err_free_channels:
> diff --git a/drivers/input/touchscreen/ti_am335x_tsc.c b/drivers/input/touchscreen/ti_am335x_tsc.c
> index 7a26810..d09e1a7 100644
> --- a/drivers/input/touchscreen/ti_am335x_tsc.c
> +++ b/drivers/input/touchscreen/ti_am335x_tsc.c
> @@ -26,6 +26,7 @@
[...]
> /*
> @@ -455,10 +460,15 @@ static int __devinit titsc_probe(struct platform_device *pdev)
>
> /* register to the input system */
> err = input_register_device(input_dev);
> - if (err)
> + if (err) {
> + dev_err(&pdev->dev, "Failed to register input device\n");
> goto err_free_irq;
> + }
>
> platform_set_drvdata(pdev, ts_dev);
> +
> + dev_info(&pdev->dev, "Initialized OK\n");

Same here

2012-10-30 18:30:33

by Pantelis Antoniou

[permalink] [raw]
Subject: Re: [PATCH] ti_tscadc: Match mfd sub devices to regmap interface

OK,

Will rework it, and repost.


On Oct 30, 2012, at 8:21 PM, Lars-Peter Clausen wrote:

> On 10/31/2012 04:55 PM, Pantelis Antoniou wrote:
>> The MFD parent device now uses a regmap, instead of direct
>> memory access. Use the same method in the sub devices to avoid
>> nasty surprises.
>>
>> Also rework the channel initialization of tiadc a bit.
>
> Those two bits are not even closely related, they should really go into
> separate patches.
>
>>
>> Signed-off-by: Pantelis Antoniou <[email protected]>
>> ---
>> drivers/iio/adc/ti_am335x_adc.c | 27 +++++++++++++++++++--------
>> drivers/input/touchscreen/ti_am335x_tsc.c | 16 +++++++++++++---
>> drivers/mfd/ti_am335x_tscadc.c | 7 +++++--
>> 3 files changed, 37 insertions(+), 13 deletions(-)
>>
> [...]
>>
>> @@ -213,6 +222,8 @@ static int __devinit tiadc_probe(struct platform_device *pdev)
>>
>> platform_set_drvdata(pdev, indio_dev);
>>
>> + dev_info(&pdev->dev, "Initialized\n");
>
> That's just noise, please don't add it. Imagine every driver did this you'd
> end up with a lot of noise your debug log.
>
>> +
>> return 0;
>>
>> err_free_channels:
>> diff --git a/drivers/input/touchscreen/ti_am335x_tsc.c b/drivers/input/touchscreen/ti_am335x_tsc.c
>> index 7a26810..d09e1a7 100644
>> --- a/drivers/input/touchscreen/ti_am335x_tsc.c
>> +++ b/drivers/input/touchscreen/ti_am335x_tsc.c
>> @@ -26,6 +26,7 @@
> [...]
>> /*
>> @@ -455,10 +460,15 @@ static int __devinit titsc_probe(struct platform_device *pdev)
>>
>> /* register to the input system */
>> err = input_register_device(input_dev);
>> - if (err)
>> + if (err) {
>> + dev_err(&pdev->dev, "Failed to register input device\n");
>> goto err_free_irq;
>> + }
>>
>> platform_set_drvdata(pdev, ts_dev);
>> +
>> + dev_info(&pdev->dev, "Initialized OK\n");
>
> Same here
>
>

2012-10-31 04:41:07

by Russ Dill

[permalink] [raw]
Subject: Re: [PATCH] ti_tscadc: Match mfd sub devices to regmap interface

On Wed, Oct 31, 2012 at 8:55 AM, Pantelis Antoniou
<[email protected]> wrote:
> The MFD parent device now uses a regmap, instead of direct
> memory access. Use the same method in the sub devices to avoid
> nasty surprises.
>
> Also rework the channel initialization of tiadc a bit.
>
> Signed-off-by: Pantelis Antoniou <[email protected]>
> ---
> drivers/iio/adc/ti_am335x_adc.c | 27 +++++++++++++++++++--------
> drivers/input/touchscreen/ti_am335x_tsc.c | 16 +++++++++++++---
> drivers/mfd/ti_am335x_tscadc.c | 7 +++++--
> 3 files changed, 37 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/iio/adc/ti_am335x_adc.c b/drivers/iio/adc/ti_am335x_adc.c
> index d48fd79..5f325c1 100644
> --- a/drivers/iio/adc/ti_am335x_adc.c
> +++ b/drivers/iio/adc/ti_am335x_adc.c
> @@ -23,7 +23,9 @@
> #include <linux/iio/iio.h>
> #include <linux/iio/machine.h>
> #include <linux/iio/driver.h>
> +#include <linux/regmap.h>
>
> +#include <linux/io.h>
> #include <linux/mfd/ti_am335x_tscadc.h>
> #include <linux/platform_data/ti_am335x_adc.h>
>
> @@ -36,13 +38,17 @@ struct tiadc_device {
>
> static unsigned int tiadc_readl(struct tiadc_device *adc, unsigned int reg)
> {
> - return readl(adc->mfd_tscadc->tscadc_base + reg);
> + unsigned int val;
> +
> + val = (unsigned int)-1;
> + regmap_read(adc->mfd_tscadc->regmap_tscadc, reg, &val);
> + return val;
> }

Would it be cleaner to instead do:

static unsigned int tiadc_readl(struct tiadc_device *adc, unsigned int reg)
{
unsigned int val;

return regmap_read(adc->mfd_tscadc->regmap_tscadc, reg, &val) ? : val;
}

or
int ret;

ret = regmap_read(adc->mfd_tscadc->regmap_tscadc, reg, &val);
return ret < 0 ret ? : val;



> static void tiadc_writel(struct tiadc_device *adc, unsigned int reg,
> unsigned int val)
> {
> - writel(val, adc->mfd_tscadc->tscadc_base + reg);
> + regmap_write(adc->mfd_tscadc->regmap_tscadc, reg, val);
> }
>
> static void tiadc_step_config(struct tiadc_device *adc_dev)
> @@ -75,22 +81,24 @@ static void tiadc_step_config(struct tiadc_device *adc_dev)
> tiadc_writel(adc_dev, REG_SE, STPENB_STEPENB);
> }
>
> -static int tiadc_channel_init(struct iio_dev *indio_dev, int channels)
> +static int tiadc_channel_init(struct iio_dev *indio_dev,
> + struct tiadc_device *adc_dev)
> {
> struct iio_chan_spec *chan_array;
> struct iio_chan_spec *chan;
> char *s;
> int i, len, size, ret;
> + int channels = adc_dev->channels;
>
> - size = indio_dev->num_channels * (sizeof(struct iio_chan_spec) + 6);
> + size = channels * (sizeof(struct iio_chan_spec) + 6);
> chan_array = kzalloc(size, GFP_KERNEL);
> if (chan_array == NULL)
> return -ENOMEM;
>
> /* buffer space is after the array */
> - s = (char *)(chan_array + indio_dev->num_channels);
> + s = (char *)(chan_array + channels);
> chan = chan_array;
> - for (i = 0; i < indio_dev->num_channels; i++, chan++, s += len + 1) {
> + for (i = 0; i < channels; i++, chan++, s += len + 1) {
>
> len = sprintf(s, "AIN%d", i);
>
> @@ -105,8 +113,9 @@ static int tiadc_channel_init(struct iio_dev *indio_dev, int channels)
> }
>
> indio_dev->channels = chan_array;
> + indio_dev->num_channels = channels;
>
> - size = (indio_dev->num_channels + 1) * sizeof(struct iio_map);
> + size = (channels + 1) * sizeof(struct iio_map);
> adc_dev->map = kzalloc(size, GFP_KERNEL);
> if (adc_dev->map == NULL) {
> kfree(chan_array);
> @@ -203,7 +212,7 @@ static int __devinit tiadc_probe(struct platform_device *pdev)
>
> tiadc_step_config(adc_dev);
>
> - err = tiadc_channel_init(indio_dev, adc_dev->channels);
> + err = tiadc_channel_init(indio_dev, adc_dev);
> if (err < 0)
> goto err_free_device;
>
> @@ -213,6 +222,8 @@ static int __devinit tiadc_probe(struct platform_device *pdev)
>
> platform_set_drvdata(pdev, indio_dev);
>
> + dev_info(&pdev->dev, "Initialized\n");
> +
> return 0;
>
> err_free_channels:
> diff --git a/drivers/input/touchscreen/ti_am335x_tsc.c b/drivers/input/touchscreen/ti_am335x_tsc.c
> index 7a26810..d09e1a7 100644
> --- a/drivers/input/touchscreen/ti_am335x_tsc.c
> +++ b/drivers/input/touchscreen/ti_am335x_tsc.c
> @@ -26,6 +26,7 @@
> #include <linux/io.h>
> #include <linux/input/ti_am335x_tsc.h>
> #include <linux/delay.h>
> +#include <linux/regmap.h>
>
> #include <linux/mfd/ti_am335x_tscadc.h>
>
> @@ -64,13 +65,17 @@ struct titsc {
>
> static unsigned int titsc_readl(struct titsc *ts, unsigned int reg)
> {
> - return readl(ts->mfd_tscadc->tscadc_base + reg);
> + unsigned int val;
> +
> + val = (unsigned int)-1;
> + regmap_read(ts->mfd_tscadc->regmap_tscadc, reg, &val);
> + return val;
> }
>
> static void titsc_writel(struct titsc *tsc, unsigned int reg,
> unsigned int val)
> {
> - writel(val, tsc->mfd_tscadc->tscadc_base + reg);
> + regmap_write(tsc->mfd_tscadc->regmap_tscadc, reg, val);
> }
>
> /*
> @@ -455,10 +460,15 @@ static int __devinit titsc_probe(struct platform_device *pdev)
>
> /* register to the input system */
> err = input_register_device(input_dev);
> - if (err)
> + if (err) {
> + dev_err(&pdev->dev, "Failed to register input device\n");
> goto err_free_irq;
> + }
>
> platform_set_drvdata(pdev, ts_dev);
> +
> + dev_info(&pdev->dev, "Initialized OK\n");
> +
> return 0;
>
> err_free_irq:
> diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c
> index cbb8b70c..4a7041c 100644
> --- a/drivers/mfd/ti_am335x_tscadc.c
> +++ b/drivers/mfd/ti_am335x_tscadc.c
> @@ -31,6 +31,7 @@ static unsigned int tscadc_readl(struct ti_tscadc_dev *tsadc, unsigned int reg)
> {
> unsigned int val;
>
> + val = (unsigned int)-1;
> regmap_read(tsadc->regmap_tscadc, reg, &val);
> return val;
> }
> @@ -68,7 +69,7 @@ static int __devinit ti_tscadc_probe(struct platform_device *pdev)
> int irq;
> int err, ctrl;
> int clk_value, clock_rate;
> - int tsc_wires, adc_channels = 0, total_channels;
> + int tsc_wires = 0, adc_channels = 0, total_channels;
>
> if (!pdata) {
> dev_err(&pdev->dev, "Could not find platform data\n");
> @@ -78,7 +79,9 @@ static int __devinit ti_tscadc_probe(struct platform_device *pdev)
> if (pdata->adc_init)
> adc_channels = pdata->adc_init->adc_channels;
>
> - tsc_wires = pdata->tsc_init->wires;
> + if (pdata->tsc_init)
> + tsc_wires = pdata->tsc_init->wires;
> +
> total_channels = tsc_wires + adc_channels;
>
> if (total_channels > 8) {
> --
> 1.7.12
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-omap" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html

2012-10-31 05:51:39

by Dmitry Torokhov

[permalink] [raw]
Subject: Re: [PATCH] ti_tscadc: Match mfd sub devices to regmap interface

On Tue, Oct 30, 2012 at 09:41:00PM -0700, Russ Dill wrote:
> On Wed, Oct 31, 2012 at 8:55 AM, Pantelis Antoniou
> <[email protected]> wrote:
> > The MFD parent device now uses a regmap, instead of direct
> > memory access. Use the same method in the sub devices to avoid
> > nasty surprises.
> >
> > Also rework the channel initialization of tiadc a bit.
> >
> > Signed-off-by: Pantelis Antoniou <[email protected]>
> > ---
> > drivers/iio/adc/ti_am335x_adc.c | 27 +++++++++++++++++++--------
> > drivers/input/touchscreen/ti_am335x_tsc.c | 16 +++++++++++++---
> > drivers/mfd/ti_am335x_tscadc.c | 7 +++++--
> > 3 files changed, 37 insertions(+), 13 deletions(-)
> >
> > diff --git a/drivers/iio/adc/ti_am335x_adc.c b/drivers/iio/adc/ti_am335x_adc.c
> > index d48fd79..5f325c1 100644
> > --- a/drivers/iio/adc/ti_am335x_adc.c
> > +++ b/drivers/iio/adc/ti_am335x_adc.c
> > @@ -23,7 +23,9 @@
> > #include <linux/iio/iio.h>
> > #include <linux/iio/machine.h>
> > #include <linux/iio/driver.h>
> > +#include <linux/regmap.h>
> >
> > +#include <linux/io.h>
> > #include <linux/mfd/ti_am335x_tscadc.h>
> > #include <linux/platform_data/ti_am335x_adc.h>
> >
> > @@ -36,13 +38,17 @@ struct tiadc_device {
> >
> > static unsigned int tiadc_readl(struct tiadc_device *adc, unsigned int reg)
> > {
> > - return readl(adc->mfd_tscadc->tscadc_base + reg);
> > + unsigned int val;
> > +
> > + val = (unsigned int)-1;
> > + regmap_read(adc->mfd_tscadc->regmap_tscadc, reg, &val);
> > + return val;
> > }
>
> Would it be cleaner to instead do:
>
> static unsigned int tiadc_readl(struct tiadc_device *adc, unsigned int reg)
> {
> unsigned int val;
>
> return regmap_read(adc->mfd_tscadc->regmap_tscadc, reg, &val) ? : val;
> }
>
> or
> int ret;
>
> ret = regmap_read(adc->mfd_tscadc->regmap_tscadc, reg, &val);
> return ret < 0 ret ? : val;

Also the function should not be returning unsigned int if it returns
errors.

Thanks.

--
Dmitry

2012-10-31 08:12:54

by Lars-Peter Clausen

[permalink] [raw]
Subject: Re: [PATCH] ti_tscadc: Match mfd sub devices to regmap interface

On 10/31/2012 05:41 AM, Russ Dill wrote:
> On Wed, Oct 31, 2012 at 8:55 AM, Pantelis Antoniou
> <[email protected]> wrote:
>> The MFD parent device now uses a regmap, instead of direct
>> memory access. Use the same method in the sub devices to avoid
>> nasty surprises.
>>
>> Also rework the channel initialization of tiadc a bit.
>>
>> Signed-off-by: Pantelis Antoniou <[email protected]>
>> ---
>> drivers/iio/adc/ti_am335x_adc.c | 27 +++++++++++++++++++--------
>> drivers/input/touchscreen/ti_am335x_tsc.c | 16 +++++++++++++---
>> drivers/mfd/ti_am335x_tscadc.c | 7 +++++--
>> 3 files changed, 37 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/iio/adc/ti_am335x_adc.c b/drivers/iio/adc/ti_am335x_adc.c
>> index d48fd79..5f325c1 100644
>> --- a/drivers/iio/adc/ti_am335x_adc.c
>> +++ b/drivers/iio/adc/ti_am335x_adc.c
>> @@ -23,7 +23,9 @@
>> #include <linux/iio/iio.h>
>> #include <linux/iio/machine.h>
>> #include <linux/iio/driver.h>
>> +#include <linux/regmap.h>
>>
>> +#include <linux/io.h>
>> #include <linux/mfd/ti_am335x_tscadc.h>
>> #include <linux/platform_data/ti_am335x_adc.h>
>>
>> @@ -36,13 +38,17 @@ struct tiadc_device {
>>
>> static unsigned int tiadc_readl(struct tiadc_device *adc, unsigned int reg)
>> {
>> - return readl(adc->mfd_tscadc->tscadc_base + reg);
>> + unsigned int val;
>> +
>> + val = (unsigned int)-1;
>> + regmap_read(adc->mfd_tscadc->regmap_tscadc, reg, &val);
>> + return val;
>> }
>
> Would it be cleaner to instead do:
>
> static unsigned int tiadc_readl(struct tiadc_device *adc, unsigned int reg)
> {
> unsigned int val;
>
> return regmap_read(adc->mfd_tscadc->regmap_tscadc, reg, &val) ? : val;
> }

In my opinion the best would be to just mimic the regmap interface here. Return
an error code or 0 and pass the value back through a pointer parameter.