[PATCH v3] mfd: ntxec: Support for EC in Tolino Shine 2 HD

[PATCH v3] mfd: ntxec: Support for EC in Tolino Shine 2 HD

[Andreas Kemnade]

Add the version of the EC in the Tolino Shine 2 HD
to the supported versions. It seems not to have an RTC
and does not ack data written to it.
The vendor kernel happily ignores write errors, using
I2C via userspace i2c-set also shows the error.
So add a quirk to ignore that error.

PWM can be successfully configured despite of that error.

Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
Reviewed-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
---
Changes in v3:
- remove have_rtc variable
- rename subdevices again

Changes in v2:
- more comments about stacking regmap construction
- fix accidential line removal
- better naming for subdevices
 drivers/mfd/ntxec.c       | 55 ++++++++++++++++++++++++++++++++++++---
 include/linux/mfd/ntxec.h |  1 +
 2 files changed, 53 insertions(+), 3 deletions(-)

diff --git a/drivers/mfd/ntxec.c b/drivers/mfd/ntxec.c
index 957de2b03529..ab6860ef3e9a 100644
--- a/drivers/mfd/ntxec.c
+++ b/drivers/mfd/ntxec.c
@@ -96,6 +96,38 @@ static struct notifier_block ntxec_restart_handler = {
 	.priority = 128,
 };
 
+static int regmap_ignore_write(void *context,
+			       unsigned int reg, unsigned int val)
+
+{
+	struct regmap *regmap = context;
+
+	regmap_write(regmap, reg, val);
+
+	return 0;
+}
+
+static int regmap_wrap_read(void *context, unsigned int reg,
+			    unsigned int *val)
+{
+	struct regmap *regmap = context;
+
+	return regmap_read(regmap, reg, val);
+}
+
+/*
+ * Some firmware versions do not ack written data, add a wrapper. It
+ * is used to stack another regmap on top.
+ */
+static const struct regmap_config regmap_config_noack = {
+	.name = "ntxec_noack",
+	.reg_bits = 8,
+	.val_bits = 16,
+	.cache_type = REGCACHE_NONE,
+	.reg_write = regmap_ignore_write,
+	.reg_read = regmap_wrap_read
+};
+
 static const struct regmap_config regmap_config = {
 	.name = "ntxec",
 	.reg_bits = 8,
@@ -104,16 +136,22 @@ static const struct regmap_config regmap_config = {
 	.val_format_endian = REGMAP_ENDIAN_BIG,
 };
 
-static const struct mfd_cell ntxec_subdevices[] = {
+static const struct mfd_cell ntxec_subdev[] = {
 	{ .name = "ntxec-rtc" },
 	{ .name = "ntxec-pwm" },
 };
 
+static const struct mfd_cell ntxec_subdev_no_rtc[] = {
+	{ .name = "ntxec-pwm" },
+};
+
 static int ntxec_probe(struct i2c_client *client)
 {
 	struct ntxec *ec;
 	unsigned int version;
 	int res;
+	const struct mfd_cell *subdevs = ntxec_subdev;
+	size_t n_subdevs = ARRAY_SIZE(ntxec_subdev);
 
 	ec = devm_kmalloc(&client->dev, sizeof(*ec), GFP_KERNEL);
 	if (!ec)
@@ -138,6 +176,16 @@ static int ntxec_probe(struct i2c_client *client)
 	switch (version) {
 	case NTXEC_VERSION_KOBO_AURA:
 		break;
+	case NTXEC_VERSION_TOLINO_SHINE2:
+		subdevs = ntxec_subdev_no_rtc;
+		n_subdevs = ARRAY_SIZE(ntxec_subdev_no_rtc);
+		/* Another regmap stacked on top of the other */
+		ec->regmap = devm_regmap_init(ec->dev, NULL,
+					      ec->regmap,
+					      &regmap_config_noack);
+		if (IS_ERR(ec->regmap))
+			return PTR_ERR(ec->regmap);
+		break;
 	default:
 		dev_err(ec->dev,
 			"Netronix embedded controller version %04x is not supported.\n",
@@ -181,8 +229,9 @@ static int ntxec_probe(struct i2c_client *client)
 
 	i2c_set_clientdata(client, ec);
 
-	res = devm_mfd_add_devices(ec->dev, PLATFORM_DEVID_NONE, ntxec_subdevices,
-				   ARRAY_SIZE(ntxec_subdevices), NULL, 0, NULL);
+	res = devm_mfd_add_devices(ec->dev, PLATFORM_DEVID_NONE,
+				   subdevs, n_subdevs,
+				   NULL, 0, NULL);
 	if (res)
 		dev_err(ec->dev, "Failed to add subdevices: %d\n", res);
 
diff --git a/include/linux/mfd/ntxec.h b/include/linux/mfd/ntxec.h
index 361204d125f1..26ab3b8eb612 100644
--- a/include/linux/mfd/ntxec.h
+++ b/include/linux/mfd/ntxec.h
@@ -33,5 +33,6 @@ static inline __be16 ntxec_reg8(u8 value)
 
 /* Known firmware versions */
 #define NTXEC_VERSION_KOBO_AURA	0xd726	/* found in Kobo Aura */
+#define NTXEC_VERSION_TOLINO_SHINE2 0xf110 /* found in Tolino Shine 2 HD */
 
 #endif
-- 
2.29.2

Re: [PATCH v3] mfd: ntxec: Support for EC in Tolino Shine 2 HD

[Jonathan Neuschäfer]

[-- Attachment #1: Type: text/plain, Size: 1120 bytes --]

On Sat, Mar 13, 2021 at 11:42:58AM +0100, Andreas Kemnade wrote:
> Add the version of the EC in the Tolino Shine 2 HD
> to the supported versions. It seems not to have an RTC
> and does not ack data written to it.
> The vendor kernel happily ignores write errors, using
> I2C via userspace i2c-set also shows the error.
> So add a quirk to ignore that error.
> 
> PWM can be successfully configured despite of that error.
> 
> Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
> Reviewed-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
> ---
[...]
> +static const struct mfd_cell ntxec_subdev_no_rtc[] = {
> +	{ .name = "ntxec-pwm" },
> +};

I left a comment/question about 'no_rtc' vs. 'pwm' in the other thread.


> -	res = devm_mfd_add_devices(ec->dev, PLATFORM_DEVID_NONE, ntxec_subdevices,
> -				   ARRAY_SIZE(ntxec_subdevices), NULL, 0, NULL);
> +	res = devm_mfd_add_devices(ec->dev, PLATFORM_DEVID_NONE,
> +				   subdevs, n_subdevs,
> +				   NULL, 0, NULL);

The last two lines might as well be one, width-wise.


This version of the patch looks nice and short :)
Jonathan

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]

Re: [PATCH v3] mfd: ntxec: Support for EC in Tolino Shine 2 HD

[Lee Jones]

On Sat, 13 Mar 2021, Andreas Kemnade wrote:

> Add the version of the EC in the Tolino Shine 2 HD
> to the supported versions. It seems not to have an RTC
> and does not ack data written to it.
> The vendor kernel happily ignores write errors, using
> I2C via userspace i2c-set also shows the error.
> So add a quirk to ignore that error.
> 
> PWM can be successfully configured despite of that error.
> 
> Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
> Reviewed-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
> ---
> Changes in v3:
> - remove have_rtc variable
> - rename subdevices again
> 
> Changes in v2:
> - more comments about stacking regmap construction
> - fix accidential line removal
> - better naming for subdevices
>  drivers/mfd/ntxec.c       | 55 ++++++++++++++++++++++++++++++++++++---
>  include/linux/mfd/ntxec.h |  1 +
>  2 files changed, 53 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/mfd/ntxec.c b/drivers/mfd/ntxec.c
> index 957de2b03529..ab6860ef3e9a 100644
> --- a/drivers/mfd/ntxec.c
> +++ b/drivers/mfd/ntxec.c
> @@ -96,6 +96,38 @@ static struct notifier_block ntxec_restart_handler = {
>  	.priority = 128,
>  };
>  
> +static int regmap_ignore_write(void *context,
> +			       unsigned int reg, unsigned int val)
> +
> +{
> +	struct regmap *regmap = context;
> +
> +	regmap_write(regmap, reg, val);
> +
> +	return 0;
> +}
> +
> +static int regmap_wrap_read(void *context, unsigned int reg,
> +			    unsigned int *val)
> +{
> +	struct regmap *regmap = context;
> +
> +	return regmap_read(regmap, reg, val);
> +}
> +
> +/*
> + * Some firmware versions do not ack written data, add a wrapper. It
> + * is used to stack another regmap on top.
> + */
> +static const struct regmap_config regmap_config_noack = {
> +	.name = "ntxec_noack",
> +	.reg_bits = 8,
> +	.val_bits = 16,
> +	.cache_type = REGCACHE_NONE,
> +	.reg_write = regmap_ignore_write,
> +	.reg_read = regmap_wrap_read
> +};
> +
>  static const struct regmap_config regmap_config = {
>  	.name = "ntxec",
>  	.reg_bits = 8,
> @@ -104,16 +136,22 @@ static const struct regmap_config regmap_config = {
>  	.val_format_endian = REGMAP_ENDIAN_BIG,
>  };
>  
> -static const struct mfd_cell ntxec_subdevices[] = {
> +static const struct mfd_cell ntxec_subdev[] = {
>  	{ .name = "ntxec-rtc" },
>  	{ .name = "ntxec-pwm" },
>  };
>  
> +static const struct mfd_cell ntxec_subdev_no_rtc[] = {
> +	{ .name = "ntxec-pwm" },
> +};
> +
>  static int ntxec_probe(struct i2c_client *client)
>  {
>  	struct ntxec *ec;
>  	unsigned int version;
>  	int res;
> +	const struct mfd_cell *subdevs = ntxec_subdev;
> +	size_t n_subdevs = ARRAY_SIZE(ntxec_subdev);

This is a little confusing.  I had to re-read to figure it out.

In my mind, it would be clearer to explicitly set these in the
switch, rather than have a default which can be over-written.

>  	ec = devm_kmalloc(&client->dev, sizeof(*ec), GFP_KERNEL);
>  	if (!ec)
> @@ -138,6 +176,16 @@ static int ntxec_probe(struct i2c_client *client)
>  	switch (version) {
>  	case NTXEC_VERSION_KOBO_AURA:
>  		break;
> +	case NTXEC_VERSION_TOLINO_SHINE2:
> +		subdevs = ntxec_subdev_no_rtc;
> +		n_subdevs = ARRAY_SIZE(ntxec_subdev_no_rtc);
> +		/* Another regmap stacked on top of the other */
> +		ec->regmap = devm_regmap_init(ec->dev, NULL,
> +					      ec->regmap,
> +					      &regmap_config_noack);
> +		if (IS_ERR(ec->regmap))
> +			return PTR_ERR(ec->regmap);
> +		break;
>  	default:
>  		dev_err(ec->dev,
>  			"Netronix embedded controller version %04x is not supported.\n",
> @@ -181,8 +229,9 @@ static int ntxec_probe(struct i2c_client *client)
>  
>  	i2c_set_clientdata(client, ec);
>  
> -	res = devm_mfd_add_devices(ec->dev, PLATFORM_DEVID_NONE, ntxec_subdevices,
> -				   ARRAY_SIZE(ntxec_subdevices), NULL, 0, NULL);
> +	res = devm_mfd_add_devices(ec->dev, PLATFORM_DEVID_NONE,
> +				   subdevs, n_subdevs,
> +				   NULL, 0, NULL);
>  	if (res)
>  		dev_err(ec->dev, "Failed to add subdevices: %d\n", res);
>  
> diff --git a/include/linux/mfd/ntxec.h b/include/linux/mfd/ntxec.h
> index 361204d125f1..26ab3b8eb612 100644
> --- a/include/linux/mfd/ntxec.h
> +++ b/include/linux/mfd/ntxec.h
> @@ -33,5 +33,6 @@ static inline __be16 ntxec_reg8(u8 value)
>  
>  /* Known firmware versions */
>  #define NTXEC_VERSION_KOBO_AURA	0xd726	/* found in Kobo Aura */
> +#define NTXEC_VERSION_TOLINO_SHINE2 0xf110 /* found in Tolino Shine 2 HD */
>  
>  #endif

-- 
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog

Re: [PATCH v3] mfd: ntxec: Support for EC in Tolino Shine 2 HD

[Andreas Kemnade]

On Mon, 15 Mar 2021 08:12:31 +0000
Lee Jones <lee.jones@linaro.org> wrote:

[...]
> >  static int ntxec_probe(struct i2c_client *client)
> >  {
> >  	struct ntxec *ec;
> >  	unsigned int version;
> >  	int res;
> > +	const struct mfd_cell *subdevs = ntxec_subdev;
> > +	size_t n_subdevs = ARRAY_SIZE(ntxec_subdev);  
> 
> This is a little confusing.  I had to re-read to figure it out.
> 
> In my mind, it would be clearer to explicitly set these in the
> switch, rather than have a default which can be over-written.
> 
yes, it is clearer. I was just afraid that your compiler cannot
figure it out that things get initialized and getting comments like
"This code has never seen a compiler."
But I will throw it against several ones.

Regards,
Andreas

Re: [PATCH v3] mfd: ntxec: Support for EC in Tolino Shine 2 HD

[Lee Jones]

On Mon, 15 Mar 2021, Andreas Kemnade wrote:

> On Mon, 15 Mar 2021 08:12:31 +0000
> Lee Jones <lee.jones@linaro.org> wrote:
> 
> [...]
> > >  static int ntxec_probe(struct i2c_client *client)
> > >  {
> > >  	struct ntxec *ec;
> > >  	unsigned int version;
> > >  	int res;
> > > +	const struct mfd_cell *subdevs = ntxec_subdev;
> > > +	size_t n_subdevs = ARRAY_SIZE(ntxec_subdev);  
> > 
> > This is a little confusing.  I had to re-read to figure it out.
> > 
> > In my mind, it would be clearer to explicitly set these in the
> > switch, rather than have a default which can be over-written.
> > 
> yes, it is clearer. I was just afraid that your compiler cannot
> figure it out that things get initialized and getting comments like
> "This code has never seen a compiler."
> But I will throw it against several ones.

Don't think so.  Just ensure you error out in the default case.

-- 
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog