[v4,2/2] Regulator: Add Anatop regulator driver

From: "Ying-Chun Liu (PaulLiu)" <paul.liu@linaro.org>

Anatop is an integrated regulator inside i.MX6 SoC.
There are 3 digital regulators which controls PU, CORE (ARM), and SOC.
And 3 analog regulators which controls 1P1, 2P5, 3P0 (USB).
This patch adds the Anatop regulator driver.

Signed-off-by: Nancy Chen <Nancy.Chen@freescale.com>
Signed-off-by: Ying-Chun Liu (PaulLiu) <paul.liu@linaro.org>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Liam Girdwood <lrg@ti.com>
---
 drivers/regulator/Kconfig                  |    6 +
 drivers/regulator/Makefile                 |    1 +
 drivers/regulator/anatop-regulator.c       |  204 ++++++++++++++++++++++++++++
 include/linux/regulator/anatop-regulator.h |   49 +++++++
 4 files changed, 260 insertions(+), 0 deletions(-)
 create mode 100644 drivers/regulator/anatop-regulator.c
 create mode 100644 include/linux/regulator/anatop-regulator.h

On Thu, Feb 09, 2012 at 04:51:26AM +0800, Ying-Chun Liu (PaulLiu) wrote:

Overall this is looking pretty good, a few issues but relatively minor.

> +	if (uv < anatop_reg->rdata->min_voltage
> +	    || uv > anatop_reg->rdata->max_voltage) {
> +		if (max_uV > anatop_reg->rdata->min_voltage)
> +			uv = anatop_reg->rdata->min_voltage;
> +		else
> +			return -EINVAL;
> +	}

This looks buggy (and is quite hard to follow).  The check for the
voltage being above the minimum voltage is fine but surely if the
voltage is too high then the first if statement will be true and max_uV
will be greater than the minimum voltage so the second if will be true.
This will cause us to choose the minimum voltage that the regulator can
do which is less than the minimum voltage requested.

You probably shouldn't be checking for the upper end of the range at all
here...

> +	if (anatop_reg->rdata->control_reg) {
> +		sel = (uv - anatop_reg->rdata->min_voltage) / 25000;
> +		val = anatop_reg->rdata->min_bit_val + sel;
> +		*selector = sel;
> +		pr_debug("%s: calculated val %d\n", __func__, val);

...instead check that selector is in range here.

> +		anatop_reg->rdata->mfd->write(anatop_reg->rdata->mfd,
> +					      anatop_reg->rdata->control_reg,
> +					      anatop_reg->rdata->vol_bit_shift,
> +					      anatop_reg->rdata->vol_bit_size,
> +					      val);

Just have a write() function in the MFD.

> +	memset(rdesc, 0, sizeof(struct regulator_desc));
> +	rdesc->name = kstrdup(of_get_property(np, "regulator-name", NULL),
> +			      GFP_KERNEL);

You should add binding documentation for the device since it's OF based.

> +	sreg->rdata->name = kstrdup(rdesc->name, GFP_KERNEL);

Can't you just point to rdesc->name?

> +	if (IS_ERR(rdev)) {
> +		dev_err(&pdev->dev, "failed to register %s\n",
> +			rdesc->name);
> +		return PTR_ERR(rdev);
> +	}

All your kstrdup()s need to be unwound in error and free cases.

> +int anatop_regulator_init(void)
> +{
> +	return platform_driver_register(&anatop_regulator);
> +}
> +
> +void anatop_regulator_exit(void)
> +{
> +	platform_driver_unregister(&anatop_regulator);
> +}
> +
> +postcore_initcall(anatop_regulator_init);
> +module_exit(anatop_regulator_exit);

These should be adjacent to the functions.

> +MODULE_AUTHOR("Freescale Semiconductor, Inc.");

Either omit this or put one or more humans as the author.

> +struct anatop_regulator {
> +       struct regulator_desc *regulator;
> +       struct regulator_init_data *initdata;
> +       struct anatop_regulator_data *rdata;
> +};

May as well just merge the regulator data in here - it's not ever used
except with a 1:1 relationship between them.  Could also directly
embed the desc and init_data, then you just have one allocation for the
data rather than a series to error check.

> +int anatop_register_regulator(
> +		struct anatop_regulator *reg_data, int reg,
> +		      struct regulator_init_data *initdata);

This looks like it's not defined any more so could be removed and since
you only appear to support OF the entire header could be merged into the
driver.

On Thu, Feb 09, 2012 at 04:51:26AM +0800, Ying-Chun Liu (PaulLiu) wrote:
> From: "Ying-Chun Liu (PaulLiu)" <paul.liu@linaro.org>
> 
> Anatop is an integrated regulator inside i.MX6 SoC.
> There are 3 digital regulators which controls PU, CORE (ARM), and SOC.
> And 3 analog regulators which controls 1P1, 2P5, 3P0 (USB).
> This patch adds the Anatop regulator driver.
> 
> Signed-off-by: Nancy Chen <Nancy.Chen@freescale.com>
> Signed-off-by: Ying-Chun Liu (PaulLiu) <paul.liu@linaro.org>
> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
> Cc: Liam Girdwood <lrg@ti.com>
> ---
>  drivers/regulator/Kconfig                  |    6 +
>  drivers/regulator/Makefile                 |    1 +
>  drivers/regulator/anatop-regulator.c       |  204 ++++++++++++++++++++++++++++
>  include/linux/regulator/anatop-regulator.h |   49 +++++++
>  4 files changed, 260 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/regulator/anatop-regulator.c
>  create mode 100644 include/linux/regulator/anatop-regulator.h
> 
> diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
> index 7a61b17..5fbcda2 100644
> --- a/drivers/regulator/Kconfig
> +++ b/drivers/regulator/Kconfig
> @@ -335,5 +335,11 @@ config REGULATOR_AAT2870
>  	  If you have a AnalogicTech AAT2870 say Y to enable the
>  	  regulator driver.
>  
> +config REGULATOR_ANATOP
> +	tristate "ANATOP LDO regulators"
> +	depends on MFD_ANATOP
> +	help
> +	  Say y here to support ANATOP LDOs regulators.
> +
>  endif
>  
> diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
> index 503bac8..8440871 100644
> --- a/drivers/regulator/Makefile
> +++ b/drivers/regulator/Makefile
> @@ -48,5 +48,6 @@ obj-$(CONFIG_REGULATOR_AB8500)	+= ab8500.o
>  obj-$(CONFIG_REGULATOR_DB8500_PRCMU) += db8500-prcmu.o
>  obj-$(CONFIG_REGULATOR_TPS65910) += tps65910-regulator.o
>  obj-$(CONFIG_REGULATOR_AAT2870) += aat2870-regulator.o
> +obj-$(CONFIG_REGULATOR_ANATOP) += anatop-regulator.o
>  
>  ccflags-$(CONFIG_REGULATOR_DEBUG) += -DDEBUG
> diff --git a/drivers/regulator/anatop-regulator.c b/drivers/regulator/anatop-regulator.c
> new file mode 100644
> index 0000000..d800c88
> --- /dev/null
> +++ b/drivers/regulator/anatop-regulator.c
> @@ -0,0 +1,204 @@
> +/*
> + * Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved.
> + */
> +
> +/*
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> +
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> +
> + * You should have received a copy of the GNU General Public License along
> + * with this program; if not, write to the Free Software Foundation, Inc.,
> + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
> + */
> +
> +#include <linux/slab.h>
> +#include <linux/device.h>
> +#include <linux/module.h>
> +#include <linux/err.h>
> +#include <linux/io.h>
> +#include <linux/platform_device.h>
> +#include <linux/regulator/driver.h>
> +#include <linux/regulator/anatop-regulator.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +#include <linux/regulator/of_regulator.h>
> +
> +static int anatop_set_voltage(struct regulator_dev *reg, int min_uV,
> +				  int max_uV, unsigned *selector)
> +{
> +	struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
> +	u32 val, sel;
> +	int uv;
> +
> +	uv = min_uV;
> +	pr_debug("%s: uv %d, min %d, max %d\n", __func__,

I would suggest dev_dbg in device driver.

> +		 uv, anatop_reg->rdata->min_voltage,
> +		 anatop_reg->rdata->max_voltage);
> +
> +	if (uv < anatop_reg->rdata->min_voltage
> +	    || uv > anatop_reg->rdata->max_voltage) {
> +		if (max_uV > anatop_reg->rdata->min_voltage)
> +			uv = anatop_reg->rdata->min_voltage;
> +		else
> +			return -EINVAL;
> +	}
> +
> +	if (anatop_reg->rdata->control_reg) {
> +		sel = (uv - anatop_reg->rdata->min_voltage) / 25000;
> +		val = anatop_reg->rdata->min_bit_val + sel;
> +		*selector = sel;
> +		pr_debug("%s: calculated val %d\n", __func__, val);
> +		anatop_reg->rdata->mfd->write(anatop_reg->rdata->mfd,
> +					      anatop_reg->rdata->control_reg,
> +					      anatop_reg->rdata->vol_bit_shift,
> +					      anatop_reg->rdata->vol_bit_size,
> +					      val);
> +		return 0;
> +	} else {
> +		return -ENOTSUPP;
> +	}
> +}
> +
> +static int anatop_get_voltage_sel(struct regulator_dev *reg)
> +{
> +	struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
> +	int selector;
> +	struct anatop_regulator_data *rdata = anatop_reg->rdata;
> +
> +	if (rdata->control_reg) {
> +		u32 val = rdata->mfd->read(rdata->mfd,
> +				     rdata->control_reg,
> +				     rdata->vol_bit_shift,
> +				     rdata->vol_bit_size);
> +		selector = val - rdata->min_bit_val;
> +		return selector;
> +	} else {
> +		return -ENOTSUPP;
> +	}
> +}
> +
> +static int anatop_list_voltage(struct regulator_dev *dev, unsigned selector)
> +{
> +	struct anatop_regulator *anatop_reg = rdev_get_drvdata(dev);
> +	int uv;
> +	struct anatop_regulator_data *rdata = anatop_reg->rdata;
> +
> +	uv = rdata->min_voltage + selector * 25000;
> +	pr_debug("vddio = %d, selector = %u\n", uv, selector);
> +	return uv;
> +}
> +
> +static struct regulator_ops anatop_rops = {
> +	.set_voltage     = anatop_set_voltage,
> +	.get_voltage_sel = anatop_get_voltage_sel,
> +	.list_voltage    = anatop_list_voltage,
> +};
> +
> +int anatop_regulator_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct device_node *np = dev->of_node;
> +	struct regulator_desc *rdesc;
> +	struct regulator_dev *rdev;
> +	struct anatop_regulator *sreg;
> +	struct regulator_init_data *initdata;
> +	struct anatop *anatopmfd = dev_get_drvdata(pdev->dev.parent);
> +	const __be32 *rval;
> +	u64 ofsize;
> +
> +	initdata = of_get_regulator_init_data(dev, dev->of_node);
> +	sreg = devm_kzalloc(dev, sizeof(struct anatop_regulator), GFP_KERNEL);
> +	if (!sreg)
> +		return -EINVAL;
> +	rdesc = devm_kzalloc(dev, sizeof(struct regulator_desc), GFP_KERNEL);
> +	if (!rdesc)
> +		return -EINVAL;
> +	sreg->initdata = initdata;
> +	sreg->regulator = rdesc;
> +	memset(rdesc, 0, sizeof(struct regulator_desc));
> +	rdesc->name = kstrdup(of_get_property(np, "regulator-name", NULL),
> +			      GFP_KERNEL);

We can probably reuse the regulator's node name here to save property
regulator-name.

> +	rdesc->ops = &anatop_rops;
> +	rdesc->type = REGULATOR_VOLTAGE;
> +	rdesc->owner = THIS_MODULE;
> +	sreg->rdata = devm_kzalloc(dev,
> +				   sizeof(struct anatop_regulator_data),
> +				   GFP_KERNEL);
> +	sreg->rdata->name = kstrdup(rdesc->name, GFP_KERNEL);
> +	rval = of_get_address(np, 0, &ofsize, NULL);
> +	if (rval) {
> +		sreg->rdata->control_reg = be32_to_cpu(rval[0]);
> +		sreg->rdata->vol_bit_shift = be32_to_cpu(rval[1]);

I'm not sure you can (ab)use 'reg' property for bit shift.  We may
need to have a property for it.

> +	}
> +	sreg->rdata->mfd = anatopmfd;
> +	sreg->rdata->vol_bit_size = (int)ofsize;
> +	rval = of_get_property(np, "min-bit-val", NULL);
> +	if (rval)
> +		sreg->rdata->min_bit_val = be32_to_cpu(*rval);
> +	rval = of_get_property(np, "min-voltage", NULL);
> +	if (rval)
> +		sreg->rdata->min_voltage = be32_to_cpu(*rval);
> +	rval = of_get_property(np, "max-voltage", NULL);
> +	if (rval)
> +		sreg->rdata->max_voltage = be32_to_cpu(*rval);

We need a sensible binding document to understand those.  But at least,
shouldn't min-voltage and max-voltage be retrieved as the common
regulator binding documented in
Documentation/devicetree/bindings/regulator/regulator.txt?

> +
> +	/* register regulator */
> +	rdev = regulator_register(rdesc, &pdev->dev,
> +				  initdata, sreg, pdev->dev.of_node);
> +	platform_set_drvdata(pdev, rdev);
> +
> +	if (IS_ERR(rdev)) {
> +		dev_err(&pdev->dev, "failed to register %s\n",
> +			rdesc->name);
> +		return PTR_ERR(rdev);
> +	}
> +
> +	return 0;
> +}
> +
> +int anatop_regulator_remove(struct platform_device *pdev)
> +{
> +	struct regulator_dev *rdev = platform_get_drvdata(pdev);
> +	regulator_unregister(rdev);
> +	return 0;
> +}
> +
> +struct of_device_id __devinitdata of_anatop_regulator_match_tbl[] = {
> +	{ .compatible = "fsl,anatop-regulator", },
> +	{ /* end */ }
> +};
> +
> +

One blank line is enough.

> +struct platform_driver anatop_regulator = {
> +	.driver = {
> +		.name	= "anatop_regulator",
> +		.owner  = THIS_MODULE,
> +		.of_match_table = of_anatop_regulator_match_tbl,
> +	},
> +	.probe	= anatop_regulator_probe,
> +	.remove	= anatop_regulator_remove,
> +};
> +
> +int anatop_regulator_init(void)
> +{
> +	return platform_driver_register(&anatop_regulator);
> +}
> +
> +void anatop_regulator_exit(void)
> +{
> +	platform_driver_unregister(&anatop_regulator);
> +}
> +
> +postcore_initcall(anatop_regulator_init);
> +module_exit(anatop_regulator_exit);
> +
> +MODULE_AUTHOR("Freescale Semiconductor, Inc.");
> +MODULE_DESCRIPTION("ANATOP Regulator driver");
> +MODULE_LICENSE("GPL");

"GPL v2"?

> diff --git a/include/linux/regulator/anatop-regulator.h b/include/linux/regulator/anatop-regulator.h
> new file mode 100644
> index 0000000..089d519
> --- /dev/null
> +++ b/include/linux/regulator/anatop-regulator.h
> @@ -0,0 +1,49 @@
> +/*
> + * Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved.
> + */
> +
> +/*
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> +
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> +
> + * You should have received a copy of the GNU General Public License along
> + * with this program; if not, write to the Free Software Foundation, Inc.,
> + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
> + */
> +
> +#ifndef __ANATOP_REGULATOR_H
> +#define __ANATOP_REGULATOR_H

Have a blank line here.

> +#include <linux/regulator/driver.h>
> +#include <linux/mfd/anatop.h>
> +
> +struct anatop_regulator {
> +	struct regulator_desc *regulator;
> +	struct regulator_init_data *initdata;
> +	struct anatop_regulator_data *rdata;
> +};
> +
> +

Drop one blank line here.

> +struct anatop_regulator_data {
> +	const char *name;
> +

Nit: drop this blank line.

> +	u32 control_reg;
> +	struct anatop *mfd;
> +	int vol_bit_shift;
> +	int vol_bit_size;
> +	int min_bit_val;
> +	int min_voltage;
> +	int max_voltage;
> +};
> +
It seems to me that anatop_regulator_data should be put before 
anatop_regulator.

Regards,
Shawn

> +int anatop_register_regulator(
> +		struct anatop_regulator *reg_data, int reg,
> +		      struct regulator_init_data *initdata);
> +
> +#endif /* __ANATOP_REGULATOR_H */
> -- 
> 1.7.8.3
>

On Fri, Feb 10, 2012 at 10:36:38PM -0800, Shawn Guo wrote:
> On Thu, Feb 09, 2012 at 04:51:26AM +0800, Ying-Chun Liu (PaulLiu) wrote:

> > +	rval = of_get_property(np, "min-voltage", NULL);
> > +	if (rval)
> > +		sreg->rdata->min_voltage = be32_to_cpu(*rval);
> > +	rval = of_get_property(np, "max-voltage", NULL);
> > +	if (rval)
> > +		sreg->rdata->max_voltage = be32_to_cpu(*rval);

> We need a sensible binding document to understand those.  But at least,
> shouldn't min-voltage and max-voltage be retrieved as the common
> regulator binding documented in
> Documentation/devicetree/bindings/regulator/regulator.txt?

Normally this would be a bad idea as the set of voltages that can safely
be used on a given board might differ from those which are supported by
the device.  However in this case you might be OK as this is all
internal to the SoC and so presumably won't vary from board to board.