[PATCH 1/2] power: regulator: add driver for ANATOP regulator

[Jaehoon Chung]

Dear Ying-Chun

On 3/8/21 3:18 AM, Ying-Chun Liu wrote:
> From: "Ying-Chun Liu (PaulLiu)" <paul.liu at 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: Ying-Chun Liu (PaulLiu) <paul.liu at linaro.org>
> ---
>  drivers/power/regulator/Kconfig            |  10 +
>  drivers/power/regulator/Makefile           |   1 +
>  drivers/power/regulator/anatop_regulator.c | 289 +++++++++++++++++++++
>  3 files changed, 300 insertions(+)
>  create mode 100644 drivers/power/regulator/anatop_regulator.c
> 
> diff --git a/drivers/power/regulator/Kconfig b/drivers/power/regulator/Kconfig
> index fbbea18c7d..1cd1f3f5ed 100644
> --- a/drivers/power/regulator/Kconfig
> +++ b/drivers/power/regulator/Kconfig
> @@ -312,6 +312,16 @@ config DM_REGULATOR_STPMIC1
>  	by the PMIC device. This driver is controlled by a device tree node
>  	which includes voltage limits.
>  
> +config DM_REGULATOR_ANATOP
> +	bool "Enable driver for ANATOP regulators"
> +	depends on DM_REGULATOR
> +	select REGMAP
> +	select SYSCON
> +	help
> +	Enable support for the Freescale i.MX on-chip ANATOP LDOs
> +	regulators. It is recommended that this option be enabled on
> +	i.MX6 platform.
> +
>  config SPL_DM_REGULATOR_STPMIC1
>  	bool "Enable driver for STPMIC1 regulators in SPL"
>  	depends on SPL_DM_REGULATOR && PMIC_STPMIC1
> diff --git a/drivers/power/regulator/Makefile b/drivers/power/regulator/Makefile
> index 9d58112dcb..e7198da911 100644
> --- a/drivers/power/regulator/Makefile
> +++ b/drivers/power/regulator/Makefile
> @@ -30,3 +30,4 @@ obj-$(CONFIG_DM_REGULATOR_TPS65910) += tps65910_regulator.o
>  obj-$(CONFIG_DM_REGULATOR_TPS62360) += tps62360_regulator.o
>  obj-$(CONFIG_$(SPL_)DM_REGULATOR_STPMIC1) += stpmic1.o
>  obj-$(CONFIG_DM_REGULATOR_TPS65941) += tps65941_regulator.o
> +obj-$(CONFIG_$(SPL_)DM_REGULATOR_ANATOP) += anatop_regulator.o
> diff --git a/drivers/power/regulator/anatop_regulator.c b/drivers/power/regulator/anatop_regulator.c
> new file mode 100644
> index 0000000000..2bb5cdbac5
> --- /dev/null
> +++ b/drivers/power/regulator/anatop_regulator.c
> @@ -0,0 +1,289 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +//
> +// Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved.
> +// Copyright (C) 2021 Linaro
> +
> +#include <common.h>
> +#include <errno.h>
> +#include <dm.h>
> +#include <log.h>
> +#include <linux/delay.h>
> +#include <linux/err.h>
> +#include <power/pmic.h>
> +#include <power/regulator.h>
> +#include <regmap.h>
> +#include <syscon.h>
> +#include <linux/bitops.h>
> +#include <linux/ioport.h>
> +#include <dm/device-internal.h>
> +#include <dm/device_compat.h>
> +#include <dm/read.h>

Well, i think that it can be removed more than now.

> +
> +#define LDO_RAMP_UP_UNIT_IN_CYCLES      64 /* 64 cycles per step */
> +#define LDO_RAMP_UP_FREQ_IN_MHZ         24 /* cycle based on 24M OSC */
> +
> +#define LDO_POWER_GATE			0x00
> +#define LDO_FET_FULL_ON			0x1f
> +
> +struct anatop_regulator {
> +	const char *name;
> +	u32 control_reg;
> +	u32 vol_bit_shift;
> +	u32 vol_bit_width;
> +	u32 min_bit_val;
> +	u32 min_voltage;
> +	u32 max_voltage;
> +	u32 delay_reg;
> +	u32 delay_bit_shift;
> +	u32 delay_bit_width;
> +};
> +
> +static u32 anatop_get_bits(struct udevice *dev, u32 addr, int bit_shift,
> +			   int bit_width)
> +{
> +	struct udevice *syscon;
> +	struct regmap *regmap;
> +	int err;
> +	u32 val, mask;
> +
> +	syscon = dev_get_parent(dev);
> +	if (!syscon) {
> +		dev_err(dev, "%s: unable to find syscon device\n", __func__);
> +		return err;
> +	}
> +
> +	regmap = syscon_get_regmap(syscon);
> +	if (IS_ERR(regmap)) {
> +		dev_err(dev, "%s: unable to find regmap (%ld)\n", __func__,
> +			PTR_ERR(regmap));
> +		return PTR_ERR(regmap);
> +	}
> +
> +	if (bit_width == 32)

Use macro instead of 32, plz.

> +		mask = ~0;
> +	else
> +		mask = (1 << bit_width) - 1;
> +
> +	err = regmap_read(regmap, addr, &val);
> +	if (err)
> +		return err;
> +
> +	val = (val >> bit_shift) & mask;
> +
> +	return val;
> +}
> +
> +void anatop_set_bits(struct udevice *dev, u32 addr, int bit_shift,
> +		     int bit_width, u32 data)

static?
doesn't it need to return int type? 
If there is a somehting failed, it seems that it needs to pass the error number.
(get_bits is returend to error..but set_bits doesn't return. It's strange.)

And How about passing the struct anatop_regulator instead of each values?
anatop_get/set_bits(struct anatop_regulator *regulator) {
..
}

> +{
> +	struct udevice *syscon;
> +	struct regmap *regmap;
> +	int err;
> +	u32 val, mask;
> +
> +	syscon = dev_get_parent(dev);
> +	if (!syscon) {
> +		dev_err(dev, "%s: unable to find syscon device\n", __func__);
> +		return;
> +	}
> +
> +	regmap = syscon_get_regmap(syscon);
> +	if (IS_ERR(regmap)) {
> +		dev_err(dev,
> +			"%s: unable to find regmap (%ld)\n", __func__,
> +			PTR_ERR(regmap));
> +		return;
> +	}
> +
> +	if (bit_width == 32)
> +		mask = ~0;
> +	else
> +		mask = (1 << bit_width) - 1;
> +
> +	err = regmap_read(regmap, addr, &val);
> +	if (err) {
> +		dev_err(dev,
> +			"%s: cannot read reg (%d)\n", __func__,
> +			err);
> +		return;
> +	}
> +	val = val & ~(mask << bit_shift);
> +	err = regmap_write(regmap, addr, (data << bit_shift) | val);
> +	if (err) {
> +		dev_err(dev,
> +			"%s: cannot wrie reg (%d)\n", __func__,
> +			err);
> +		return;
> +	}
> +}
> +
> +static int anatop_set_voltage(struct udevice *dev, int uV)
> +{
> +	const struct anatop_regulator *anatop_reg = dev_get_plat(dev);
> +	u32 val;
> +	u32 sel;
> +	int delayus = 0;
> +	int ret = 0;
> +	int uv;
> +
> +	uv = uV;

Not need to assign at here. Assign to above.
int uv = uV;


> +	dev_dbg(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)
> +		return -EINVAL;
> +
> +	if (!anatop_reg->control_reg)
> +		return -ENOTSUPP;
> +
> +	sel = DIV_ROUND_UP(uv - anatop_reg->min_voltage, 25000);

What is 25000? If it's min value, use MACRO, plz.

> +	if (sel * 25000 + anatop_reg->min_voltage > anatop_reg->max_voltage)
> +		return -EINVAL;
> +	val = anatop_reg->min_bit_val + sel;
> +	dev_dbg(dev, "%s: calculated val %d\n", __func__, val);
> +
> +	/* check whether need to care about LDO ramp up speed */
> +	if (anatop_reg->delay_bit_width) {
> +		/*
> +		 * the delay for LDO ramp up time is
> +		 * based on the register setting, we need
> +		 * to calculate how many steps LDO need to
> +		 * ramp up, and how much delay needed. (us)
> +		 */
> +		u32 old_sel;
> +		u32 new_sel = sel;
> +
> +		old_sel = anatop_get_bits(dev,
> +					  anatop_reg->control_reg,
> +					  anatop_reg->vol_bit_shift,
> +					  anatop_reg->vol_bit_width);
> +		old_sel = old_sel - anatop_reg->min_bit_val;
> +
> +		if (new_sel > old_sel) {
> +			val = anatop_get_bits(dev,
> +					      anatop_reg->delay_reg,
> +					      anatop_reg->delay_bit_shift,
> +					      anatop_reg->delay_bit_width);
> +			delayus = (new_sel - old_sel) *
> +				(LDO_RAMP_UP_UNIT_IN_CYCLES << val) /
> +				LDO_RAMP_UP_FREQ_IN_MHZ + 1;
> +		}
> +	}
> +
> +	anatop_set_bits(dev,
> +			anatop_reg->control_reg,
> +			anatop_reg->vol_bit_shift,
> +			anatop_reg->vol_bit_width,
> +			val);
> +
> +	if (delayus)
> +		udelay(delayus);
> +
> +	return ret;
> +}
> +
> +static int anatop_get_voltage(struct udevice *dev)
> +{
> +	const struct anatop_regulator *anatop_reg = dev_get_plat(dev);
> +	u32 val;
> +	u32 sel;
> +
> +	val = anatop_get_bits(dev,
> +			      anatop_reg->control_reg,
> +			      anatop_reg->vol_bit_shift,
> +			      anatop_reg->vol_bit_width);
> +	sel = val - anatop_reg->min_bit_val;
> +
> +	return sel * 25000 + anatop_reg->min_voltage;
> +}
> +
> +static const struct dm_regulator_ops anatop_regulator_ops = {
> +	.set_value = anatop_set_voltage,
> +	.get_value = anatop_get_voltage,
> +};
> +
> +static int anatop_regulator_probe(struct udevice *dev)
> +{
> +	struct anatop_regulator *sreg;
> +	int ret = 0;
> +
> +	sreg = dev_get_plat(dev);
> +	if (!sreg) {
> +		dev_err(dev, "failed to get plat data\n");
> +		return -ENOMEM;
> +	}
> +
> +	sreg->name = ofnode_read_string(dev_ofnode(dev), "regulator-name");
> +	if (!sreg->name) {
> +		dev_err(dev, "failed to get a regulator-name\n");
> +		return -EINVAL;
> +	}
> +
> +	ret = ofnode_read_u32(dev_ofnode(dev),
> +			      "anatop-reg-offset",
> +			      &sreg->control_reg);
> +	if (ret) {
> +		dev_err(dev, "no anatop-reg-offset property set\n");
> +		return ret;
> +	}
> +	ret = ofnode_read_u32(dev_ofnode(dev),
> +			      "anatop-vol-bit-width",
> +			      &sreg->vol_bit_width);
> +	if (ret) {
> +		dev_err(dev, "no anatop-vol-bit-width property set\n");
> +		return ret;
> +	}
> +	ret = ofnode_read_u32(dev_ofnode(dev),
> +			      "anatop-vol-bit-shift",
> +			      &sreg->vol_bit_shift);
> +	if (ret) {
> +		dev_err(dev, "no anatop-vol-bit-shift property set\n");
> +		return ret;
> +	}
> +	ret = ofnode_read_u32(dev_ofnode(dev),
> +			      "anatop-min-bit-val",
> +			      &sreg->min_bit_val);
> +	if (ret) {
> +		dev_err(dev, "no anatop-min-bit-val property set\n");
> +		return ret;
> +	}
> +	ret = ofnode_read_u32(dev_ofnode(dev),
> +			      "anatop-min-voltage",
> +			      &sreg->min_voltage);

I don't know why anatop-min-voltage is need?
Doesn't it use "regulator-min-microvolt"?


> +	if (ret) {
> +		dev_err(dev, "no anatop-min-voltage property set\n");
> +		return ret;
> +	}
> +	ret = ofnode_read_u32(dev_ofnode(dev),
> +			      "anatop-max-voltage",
> +			      &sreg->max_voltage);

Ditto.

Best Regards,
Jaehoon Chung

> +	if (ret) {
> +		dev_err(dev, "no anatop-max-voltage property set\n");
> +		return ret;
> +	}
> +
> +	/* read LDO ramp up setting, only for core reg */
> +	ofnode_read_u32(dev_ofnode(dev), "anatop-delay-reg-offset",
> +			&sreg->delay_reg);
> +	ofnode_read_u32(dev_ofnode(dev), "anatop-delay-bit-width",
> +			&sreg->delay_bit_width);
> +	ofnode_read_u32(dev_ofnode(dev), "anatop-delay-bit-shift",
> +			&sreg->delay_bit_shift);
> +
> +	return 0;
> +}
> +
> +static const struct udevice_id of_anatop_regulator_match_tbl[] = {
> +	{ .compatible = "fsl,anatop-regulator", },
> +	{ /* end */ }
> +};
> +
> +U_BOOT_DRIVER(anatop_regulator) = {
> +	.name = "anatop_regulator",
> +	.id = UCLASS_REGULATOR,
> +	.ops = &anatop_regulator_ops,
> +	.of_match = of_anatop_regulator_match_tbl,
> +	.plat_auto = sizeof(struct anatop_regulator),
> +	.probe = anatop_regulator_probe,
> +};
>