Re: [PATCH v10] Regulator: Add Anatop regulator driver

[Jean-Christophe PLAGNIOL-VILLARD]

On 17:59 Thu 08 Mar     , Ying-Chun Liu (PaulLiu) wrote:
> From: "Ying-Chun Liu (PaulLiu)" <paul.liu@xxxxxxxxxx>
> 
> 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@xxxxxxxxxxxxx>
> Signed-off-by: Ying-Chun Liu (PaulLiu) <paul.liu@xxxxxxxxxx>
> Acked-by: Shawn Guo <shawn.guo@xxxxxxxxxx>
> Cc: Mark Brown <broonie@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
> Cc: Liam Girdwood <lrg@xxxxxx>
> Cc: Samuel Ortiz <sameo@xxxxxxxxxxxxxxx>
> Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@xxxxxxxxxxxx>
> Cc: Axel Lin <axel.lin@xxxxxxxxx>
> ---
>  .../bindings/regulator/anatop-regulator.txt        |   28 +++
>  drivers/regulator/Kconfig                          |    8 +
>  drivers/regulator/Makefile                         |    1 +
>  drivers/regulator/anatop-regulator.c               |  236 ++++++++++++++++++++
>  4 files changed, 273 insertions(+), 0 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/regulator/anatop-regulator.txt
>  create mode 100644 drivers/regulator/anatop-regulator.c
> 
> diff --git a/Documentation/devicetree/bindings/regulator/anatop-regulator.txt b/Documentation/devicetree/bindings/regulator/anatop-regulator.txt
> new file mode 100644
> index 0000000..73363e76
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/regulator/anatop-regulator.txt
> @@ -0,0 +1,28 @@
> +Anatop Voltage regulators
> +
> +Required properties:
> +- compatible: Must be "fsl,anatop-regulator"
> +- anatop-vol-bit-shift: Bit shift for the register
> +- anatop-vol-bit-width: Number of bits used in the register
> +- anatop-min-bit-val: Minimum value of this register
> +- anatop-min-voltage: Minimum voltage of this regulator
> +- anatop-max-voltage: Maximum voltage of this regulator
> +
> +Any property defined as part of the core regulator
> +binding, defined in regulator.txt, can also be used.
> +
> +Example:
> +
> +	reg_vddpu: regulator-vddpu@140 {
> +		compatible = "fsl,anatop-regulator";
> +		regulator-name = "vddpu";
> +		regulator-min-microvolt = <725000>;
> +		regulator-max-microvolt = <1300000>;
> +		regulator-always-on;
> +		reg = <0x140>;
> +		anatop-vol-bit-shift = <9>;
> +		anatop-vol-bit-width = <5>;
> +		anatop-min-bit-val = <1>;
> +		anatop-min-voltage = <725000>;
> +		anatop-max-voltage = <1300000>;
> +	};
> diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
> index 7a61b17..3857209 100644
> --- a/drivers/regulator/Kconfig
> +++ b/drivers/regulator/Kconfig
> @@ -213,6 +213,14 @@ config REGULATOR_PCAP
>  	 This driver provides support for the voltage regulators of the
>  	 PCAP2 PMIC.
>  
> +config REGULATOR_ANATOP
> +	tristate "Freescale i.MX on-chip ANATOP LDO regulators"
> +	depends on MFD_ANATOP
> +	help
> +	  Say y here to support Freescale i.MX on-chip ANATOP LDOs
> +	  regulators. It is recommended that this option be
> +	  enabled on i.MX6 platform.
> +
>  config REGULATOR_MC13XXX_CORE
>  	tristate
>  
> 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..133a17b
> --- /dev/null
> +++ b/drivers/regulator/anatop-regulator.c
> @@ -0,0 +1,236 @@
> +/*
> + * 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/of.h>
> +#include <linux/of_address.h>
> +#include <linux/mfd/anatop.h>
> +#include <linux/regulator/driver.h>
> +#include <linux/regulator/of_regulator.h>
> +
> +struct anatop_regulator {
> +	const char *name;
> +	u32 control_reg;
> +	struct anatop *mfd;
> +	int vol_bit_shift;
> +	int vol_bit_width;
> +	int min_bit_val;
> +	int min_voltage;
> +	int max_voltage;
> +	struct regulator_desc rdesc;
> +	struct regulator_init_data *initdata;
> +};
> +
> +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;
> +	dev_dbg(&reg->dev, "%s: uv %d, min %d, max %d\n", __func__,
> +		uv, anatop_reg->min_voltage,
> +		anatop_reg->max_voltage);
> +
> +	if (uv < anatop_reg->min_voltage) {
> +		if (max_uV > anatop_reg->min_voltage)
> +			uv = anatop_reg->min_voltage;
> +		else
> +			return -EINVAL;
> +	}
> +
> +	if (anatop_reg->control_reg) {
> +		sel = (uv - anatop_reg->min_voltage) / 25000;
> +		if (sel * 25000 + anatop_reg->min_voltage
> +		    > anatop_reg->max_voltage)
> +			return -EINVAL;
> +		val = anatop_reg->min_bit_val + sel;
> +		*selector = sel;
> +		dev_dbg(&reg->dev, "%s: calculated val %d\n", __func__, val);
> +		anatop_set_bits(anatop_reg->mfd,
> +				anatop_reg->control_reg,
> +				anatop_reg->vol_bit_shift,
> +				anatop_reg->vol_bit_width,
> +				val);
> +		return 0;
> +	} else {
> +		return -ENOTSUPP;
> +	}
invert the test to make the code more readable
> +}
> +
> +static int anatop_get_voltage_sel(struct regulator_dev *reg)
> +{
> +	struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
> +	int selector;
> +
> +	if (anatop_reg->control_reg) {
> +		u32 val = anatop_get_bits(anatop_reg->mfd,
> +					  anatop_reg->control_reg,
> +					  anatop_reg->vol_bit_shift,
> +					  anatop_reg->vol_bit_width);
> +		selector = val - anatop_reg->min_bit_val;
> +		return selector;
why do you need selector
> +	} else {
> +		return -ENOTSUPP;
> +	}
invert the test to make the code more readable
> +}
> +
> +static int anatop_list_voltage(struct regulator_dev *reg, unsigned selector)
> +{
> +	struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
> +	int uv;
> +
> +	uv = anatop_reg->min_voltage + selector * 25000;
> +	dev_dbg(&reg->dev, "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,
> +};
> +
> +static int __devinit anatop_regulator_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
you set a dev var but use &pdev->dev most of the time
> +	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);
> +	int ret = 0;
> +
> +	initdata = of_get_regulator_init_data(dev, np);
> +	sreg = devm_kzalloc(dev, sizeof(*sreg), GFP_KERNEL);
> +	if (!sreg)
> +		return -ENOMEM;
> +	sreg->initdata = initdata;
> +	sreg->name = kstrdup(of_get_property(np, "regulator-name", NULL),
> +			     GFP_KERNEL);
> +	rdesc = &sreg->rdesc;
> +	memset(rdesc, 0, sizeof(*rdesc));
> +	rdesc->name = sreg->name;
> +	rdesc->ops = &anatop_rops;
> +	rdesc->type = REGULATOR_VOLTAGE;
> +	rdesc->owner = THIS_MODULE;
> +	sreg->mfd = anatopmfd;
> +	if (of_property_read_u32(np, "reg", &sreg->control_reg)) {
> +		dev_err(&pdev->dev, "no reg property set\n");
> +		ret = -ENODEV;
why not return the err return by the read_u32 or atleast print it
> +		goto anatop_probe_end;
> +	}
> +	if (of_property_read_u32(np, "anatop-vol-bit-width",
> +				 &sreg->vol_bit_width)) {
> +		dev_err(&pdev->dev, "no anatop-vol-bit-width property set\n");
> +		ret = -ENODEV;
> +		goto anatop_probe_end;
> +	}
> +	if (of_property_read_u32(np, "anatop-vol-bit-shift",
> +				 &sreg->vol_bit_shift)) {
> +		dev_err(&pdev->dev, "no anatop-vol-bit-shift property set\n");
> +		ret = -ENODEV;
> +		goto anatop_probe_end;
> +	}
> +	if (of_property_read_u32(np, "anatop-min-bit-val",
> +				 &sreg->min_bit_val)) {
> +		dev_err(&pdev->dev, "no anatop-min-bit-val property set\n");
> +		ret = -ENODEV;
> +		goto anatop_probe_end;
> +	}
> +	if (of_property_read_u32(np, "anatop-min-voltage",
> +				 &sreg->min_voltage)) {
> +		dev_err(&pdev->dev, "no anatop-min-voltage property set\n");
> +		ret = -ENODEV;
> +		goto anatop_probe_end;
> +	}
> +	if (of_property_read_u32(np, "anatop-max-voltage",
> +				 &sreg->max_voltage)) {
> +		dev_err(&pdev->dev, "no anatop-max-voltage property set\n");
> +		ret = -ENODEV;
> +		goto anatop_probe_end;
> +	}
> +
> +	/* register regulator */
> +	rdev = regulator_register(rdesc, &pdev->dev,
> +				  initdata, sreg, pdev->dev.of_node);
> +	if (IS_ERR(rdev)) {
> +		dev_err(&pdev->dev, "failed to register %s\n",
> +			rdesc->name);
> +		ret = PTR_ERR(rdev);
> +		goto anatop_probe_end;
> +	}
> +
> +	platform_set_drvdata(pdev, rdev);
> +
> +anatop_probe_end:
> +	if (ret != 0 && sreg->name)
> +		kfree(sreg->name);
kfree can be called with a NULL pointer
> +	return ret;
> +}
> +
> +static int __devexit anatop_regulator_remove(struct platform_device *pdev)
> +{
> +	struct regulator_dev *rdev = platform_get_drvdata(pdev);
> +	struct anatop_regulator *sreg = rdev_get_drvdata(rdev);
> +	kfree(sreg->name);
> +	regulator_unregister(rdev);
return from the unregister
> +	return 0;
> +}
Best Regards,
J.
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