diff mbox series

[RFC,v2,09/10] power: supply: Initial support for ROHM BD70528 PMIC charger block

Message ID 20190125110600.GA29332@localhost.localdomain
State New
Headers show
Series support ROHM BD70528 PMIC | expand

Commit Message

Matti Vaittinen Jan. 25, 2019, 11:06 a.m. UTC 
ROHM BD70528 PMIC includes battery charger block. Support charger
staus queries and doing few basic settings like input current limit
and charging current.

Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
---
 drivers/power/supply/Kconfig           |   9 +
 drivers/power/supply/Makefile          |   1 +
 drivers/power/supply/bd70528-charger.c | 670 +++++++++++++++++++++++++++++++++
 3 files changed, 680 insertions(+)
 create mode 100644 drivers/power/supply/bd70528-charger.c

Comments

Linus Walleij Jan. 28, 2019, 12:49 p.m. UTC | #1 
Hi Matti!

Thanks for your patch.

We are going to have a problem with the power subsystem.

These charging drivers are growing wild. This is starting to get out
of hand, we need some more framework for properly handling charging
state machines the kernel. Not specifically your problem, but
when working on the driver try to keep generic support in mind.

On Fri, Jan 25, 2019 at 12:06 PM Matti Vaittinen
<matti.vaittinen@fi.rohmeurope.com> wrote:

> +#define CHG_STAT_SUSPEND       0x0
> +#define CHG_STAT_TRICKLE       0x1
> +#define CHG_STAT_FAST          0x3
> +#define CHG_STAT_TOPOFF                0xe
> +#define CHG_STAT_DONE          0xf
> +#define CHG_STAT_OTP_TRICKLE   0x10
> +#define CHG_STAT_OTP_FAST      0x11
> +#define CHG_STAT_OTP_DONE      0x12
> +#define CHG_STAT_TSD_TRICKLE   0x20
> +#define CHG_STAT_TSD_FAST      0x21
> +#define CHG_STAT_TSD_TOPOFF    0x22
> +#define CHG_STAT_BAT_ERR       0x7f

So what I am seeing is that these states are starting to turn up in more
and more drivers, so we really need to think about a central management
component for charging state machines. I do not think they are all
that different after all.

> +BD_ERR_IRQ_HND(BAT_OV_DET, "Battery overvoltage detected\n");
> +BD_ERR_IRQ_HND(DBAT_DET, "Dead battery detected\n");
> +BD_ERR_IRQ_HND(COLD_DET, "Battery cold\n");
> +BD_ERR_IRQ_HND(HOT_DET, "Battery hot\n");
> +BD_ERR_IRQ_HND(CHG_TSD, "Charger thermal shutdown\n");
> +BD_ERR_IRQ_HND(DCIN2_OV_DET, "DCIN2 overvoltage detected\n");
> +
> +BD_INFO_IRQ_HND(BAT_OV_RES, "Battery voltage back to normal\n");
> +BD_INFO_IRQ_HND(COLD_RES, "Battery temperature back to normal\n");
> +BD_INFO_IRQ_HND(HOT_RES, "Battery temperature back to normal\n");
> +BD_INFO_IRQ_HND(BAT_RMV, "Battery removed\n");
> +BD_INFO_IRQ_HND(BAT_DET, "Battery detected\n");
> +BD_INFO_IRQ_HND(DCIN2_OV_RES, "DCIN2 voltage back to normal\n");
> +BD_INFO_IRQ_HND(DCIN2_RMV, "DCIN2 removed\n");
> +BD_INFO_IRQ_HND(DCIN2_DET, "DCIN2 detected\n");
> +BD_INFO_IRQ_HND(DCIN1_RMV, "DCIN1 removed\n");
> +BD_INFO_IRQ_HND(DCIN1_DET, "DCIN1 detected\n");

So we have states and events, and these events form edges
between the states, right?

I am certain you must have a graphical picture of this state
machine somewhere, it seems to be how charging hardware people
do their thinking.

> +/*
> + * For BD70528 voltage/current limits we happily accept any value which
> + * belongs the range. We could check if value matching the selector is
> + * desired by computing the range min + (sel - sel_low) * range step - but
> + * I guess it is enough if we use voltage/current which is closest (below)
> + * the requested?
> + */
> +static int find_selector_for_value_low(struct linear_range *r, int selectors,
> +                                      unsigned int val, unsigned int *sel,
> +                                      bool *found)
> +{
> +       int i;
> +       int ret = -EINVAL;
> +
> +       *found = false;
> +       for (i = 0; i < selectors; i++) {
> +               if (r[i].min <= val) {
> +                       if (r[i].min + r[i].step * r[i].vals >= val) {
> +                               *found = true;
> +                               *sel = r[i].low_sel + (val - r[i].min) /
> +                                      r[i].step;
> +                               ret = 0;
> +                               break;
> +                       }
> +                       /*
> +                        * If the range max is smaller than requested
> +                        * we can set the max supported value from range
> +                        */
> +                       *sel = r[i].low_sel + r[i].vals;
> +                       ret = 0;
> +               }
> +       }
> +       return ret;
> +}

If I'm not mistaken this is yet another instance of linear interpolation
from a table?

We really need to think about abstracting this. Last time this
duplication appeared I suggested adding linear interpolation
primitives to:
include/linux/fixp-arith.h

I don't know what others say though?

Yours,
Linus Walleij
Matti Vaittinen Jan. 28, 2019, 1:53 p.m. UTC | #2 
Hello Linus,

Big Thanks for the proper review at this early satge!

On Mon, Jan 28, 2019 at 01:49:04PM +0100, Linus Walleij wrote:
> Hi Matti!
> 
> Thanks for your patch.
> 
> We are going to have a problem with the power subsystem.
> 
> These charging drivers are growing wild. This is starting to get out
> of hand, we need some more framework for properly handling charging
> state machines the kernel. Not specifically your problem, but
> when working on the driver try to keep generic support in mind.

I for sure can try - but as the power subsystem is quite new to me - any
specific items you would like me to really pay attention?

> On Fri, Jan 25, 2019 at 12:06 PM Matti Vaittinen
> <matti.vaittinen@fi.rohmeurope.com> wrote:
> 
> > +#define CHG_STAT_SUSPEND       0x0
> > +#define CHG_STAT_TRICKLE       0x1
> > +#define CHG_STAT_FAST          0x3
> > +#define CHG_STAT_TOPOFF                0xe
> > +#define CHG_STAT_DONE          0xf
> > +#define CHG_STAT_OTP_TRICKLE   0x10
> > +#define CHG_STAT_OTP_FAST      0x11
> > +#define CHG_STAT_OTP_DONE      0x12
> > +#define CHG_STAT_TSD_TRICKLE   0x20
> > +#define CHG_STAT_TSD_FAST      0x21
> > +#define CHG_STAT_TSD_TOPOFF    0x22
> > +#define CHG_STAT_BAT_ERR       0x7f
> 
> So what I am seeing is that these states are starting to turn up in more
> and more drivers, so we really need to think about a central management
> component for charging state machines. I do not think they are all
> that different after all.

Any suggestions how I should take this into account with bd70528?

> > +BD_ERR_IRQ_HND(BAT_OV_DET, "Battery overvoltage detected\n");
> > +BD_ERR_IRQ_HND(DBAT_DET, "Dead battery detected\n");
> > +BD_ERR_IRQ_HND(COLD_DET, "Battery cold\n");
> > +BD_ERR_IRQ_HND(HOT_DET, "Battery hot\n");
> > +BD_ERR_IRQ_HND(CHG_TSD, "Charger thermal shutdown\n");
> > +BD_ERR_IRQ_HND(DCIN2_OV_DET, "DCIN2 overvoltage detected\n");
> > +
> > +BD_INFO_IRQ_HND(BAT_OV_RES, "Battery voltage back to normal\n");
> > +BD_INFO_IRQ_HND(COLD_RES, "Battery temperature back to normal\n");
> > +BD_INFO_IRQ_HND(HOT_RES, "Battery temperature back to normal\n");
> > +BD_INFO_IRQ_HND(BAT_RMV, "Battery removed\n");
> > +BD_INFO_IRQ_HND(BAT_DET, "Battery detected\n");
> > +BD_INFO_IRQ_HND(DCIN2_OV_RES, "DCIN2 voltage back to normal\n");
> > +BD_INFO_IRQ_HND(DCIN2_RMV, "DCIN2 removed\n");
> > +BD_INFO_IRQ_HND(DCIN2_DET, "DCIN2 detected\n");
> > +BD_INFO_IRQ_HND(DCIN1_RMV, "DCIN1 removed\n");
> > +BD_INFO_IRQ_HND(DCIN1_DET, "DCIN1 detected\n");
> 
> So we have states and events, and these events form edges
> between the states, right?

Right. State change causes an irq.

> I am certain you must have a graphical picture of this state
> machine somewhere, it seems to be how charging hardware people
> do their thinking.

I don't have any document I could link to yet. I can ask around if we
can have some public doc for this :/ And as a last resort I can do some
ASCII art in commenets - if this is seen helpfull.

> > +/*
> > + * For BD70528 voltage/current limits we happily accept any value which
> > + * belongs the range. We could check if value matching the selector is
> > + * desired by computing the range min + (sel - sel_low) * range step - but
> > + * I guess it is enough if we use voltage/current which is closest (below)
> > + * the requested?
> > + */
> > +static int find_selector_for_value_low(struct linear_range *r, int selectors,
> > +                                      unsigned int val, unsigned int *sel,
> > +                                      bool *found)
> > +{
> > +       int i;
> > +       int ret = -EINVAL;
> > +
> > +       *found = false;
> > +       for (i = 0; i < selectors; i++) {
> > +               if (r[i].min <= val) {
> > +                       if (r[i].min + r[i].step * r[i].vals >= val) {
> > +                               *found = true;
> > +                               *sel = r[i].low_sel + (val - r[i].min) /
> > +                                      r[i].step;
> > +                               ret = 0;
> > +                               break;
> > +                       }
> > +                       /*
> > +                        * If the range max is smaller than requested
> > +                        * we can set the max supported value from range
> > +                        */
> > +                       *sel = r[i].low_sel + r[i].vals;
> > +                       ret = 0;
> > +               }
> > +       }
> > +       return ret;
> > +}
> 
> If I'm not mistaken this is yet another instance of linear interpolation
> from a table?

"linear interpolation from a table" is really not part of my
vocabulary :] But I guess you know the REGULATOR_LINEAR_VOLTAGE - macro?
I borrowed the idea from there...
> 
> We really need to think about abstracting this. Last time this
> duplication appeared I suggested adding linear interpolation
> primitives to:
> include/linux/fixp-arith.h

... I really think a generic helper for this would be usefull.

It will take some time untill I can send a proper (non RFC patch) for
the charger block as I currently lack of HW I could use for testing the
charger properly. Do you think it is better to drop the charger part
from the series untill then and submit it only later? As I mentioned in
cover-letter, the charger part is currently submitted more to give an
overview of the chip than to be applied as 'finalized' version of
driver.

Br,
	Matti Vaittinen
Linus Walleij Jan. 28, 2019, 2:46 p.m. UTC | #3 
On Mon, Jan 28, 2019 at 2:54 PM Matti Vaittinen
<matti.vaittinen@fi.rohmeurope.com> wrote:

> > These charging drivers are growing wild. This is starting to get out
> > of hand, we need some more framework for properly handling charging
> > state machines the kernel. Not specifically your problem, but
> > when working on the driver try to keep generic support in mind.
>
> I for sure can try - but as the power subsystem is quite new to me - any
> specific items you would like me to really pay attention?

So I am not saying you have to do this or anything, but I think
what we need is a generic state machine and policy engine
for charging, where different charging drivers just plug in.

They all seem to have trickle and fast charging, USB phy
interaction and AC plug interaction of some kind for detecting
those and in some cases temperature detection directly
or using an ADC.

We have a bunch of drivers with software-controlled charging:
ab8500*
axp288*
etc.

If we could get just two drivers to share some changing
infrastructure we would have a start.

I have no idea how hard it could be, but I think it would
be a pretty interesting adventure if someone gathered
some different hardwares and started to generalize parts
of this.

> > So what I am seeing is that these states are starting to turn up in more
> > and more drivers, so we really need to think about a central management
> > component for charging state machines. I do not think they are all
> > that different after all.
>
> Any suggestions how I should take this into account with bd70528?

Not more than above, it is unfair to ask random contributors to
invent entire new worlds of kernel infrastructure. But I guess I
just need to say it so we are aware: this charging state machine
engine is needed. Doing it is another thing.

> > I am certain you must have a graphical picture of this state
> > machine somewhere, it seems to be how charging hardware people
> > do their thinking.
>
> I don't have any document I could link to yet. I can ask around if we
> can have some public doc for this :/ And as a last resort I can do some
> ASCII art in commenets - if this is seen helpfull.

That'd be nice.

> > If I'm not mistaken this is yet another instance of linear interpolation
> > from a table?
>
> "linear interpolation from a table" is really not part of my
> vocabulary :] But I guess you know the REGULATOR_LINEAR_VOLTAGE - macro?
> I borrowed the idea from there...

I'm referring to this essentially:
https://en.wikipedia.org/wiki/Linear_interpolation

What many charging drivers tends to do is:
- Look up where I am in a table, say between row 4 and 5
- For x-axis n..n+1, interpolate y-axis between
  the values found for x=1 and x=n+1 using
  common linear interpolation.

> > We really need to think about abstracting this. Last time this
> > duplication appeared I suggested adding linear interpolation
> > primitives to:
> > include/linux/fixp-arith.h
>
> ... I really think a generic helper for this would be usefull.

Indeed.

> It will take some time untill I can send a proper (non RFC patch) for
> the charger block as I currently lack of HW I could use for testing the
> charger properly. Do you think it is better to drop the charger part
> from the series untill then and submit it only later?

Not really, we need to face the hardware out there and I usually
use the stance "rough consensus and running code". If noone
invents a unified charging framework, your hardware needs to
run so a custom driver isn't that bad either, and it's still better
to have it in-tree than to maintain it out-of-tree as long as it
is clearly isolated.

> As I mentioned in
> cover-letter, the charger part is currently submitted more to give an
> overview of the chip than to be applied as 'finalized' version of
> driver.

That's OK.

Yours,
Linus Walleij
diff mbox series

Patch

diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
index e901b9879e7e..903c97a67bf0 100644
--- a/drivers/power/supply/Kconfig
+++ b/drivers/power/supply/Kconfig
@@ -660,4 +660,13 @@  config FUEL_GAUGE_SC27XX
 	 Say Y here to enable support for fuel gauge with SC27XX
 	 PMIC chips.
 
+config CHARGER_BD70528
+	tristate "ROHM bd70528 charger driver"
+	depends on MFD_ROHM_BD70528
+	default n
+	help
+	 Say Y here to enable support for getting battery status
+	 information and altering charger configurations from charger
+	 block of the ROHM BD70528 Power Management IC.
+
 endif # POWER_SUPPLY
diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile
index b731c2a9b695..c60387b04bfa 100644
--- a/drivers/power/supply/Makefile
+++ b/drivers/power/supply/Makefile
@@ -87,3 +87,4 @@  obj-$(CONFIG_AXP288_CHARGER)	+= axp288_charger.o
 obj-$(CONFIG_CHARGER_CROS_USBPD)	+= cros_usbpd-charger.o
 obj-$(CONFIG_CHARGER_SC2731)	+= sc2731_charger.o
 obj-$(CONFIG_FUEL_GAUGE_SC27XX)	+= sc27xx_fuel_gauge.o
+obj-$(CONFIG_CHARGER_BD70528)	+= bd70528-charger.o
diff --git a/drivers/power/supply/bd70528-charger.c b/drivers/power/supply/bd70528-charger.c
new file mode 100644
index 000000000000..ede8744bd6b1
--- /dev/null
+++ b/drivers/power/supply/bd70528-charger.c
@@ -0,0 +1,670 @@ 
+// SPDX-License-Identifier: GPL-2.0-or-later
+//
+// Copyright (C) 2018 ROHM Semiconductors
+//
+// power-supply driver for ROHM BD70528 PMIC
+
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/rohm-bd70528.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/power_supply.h>
+
+#define CHG_STAT_SUSPEND	0x0
+#define CHG_STAT_TRICKLE	0x1
+#define CHG_STAT_FAST		0x3
+#define CHG_STAT_TOPOFF		0xe
+#define CHG_STAT_DONE		0xf
+#define CHG_STAT_OTP_TRICKLE	0x10
+#define CHG_STAT_OTP_FAST	0x11
+#define CHG_STAT_OTP_DONE	0x12
+#define CHG_STAT_TSD_TRICKLE	0x20
+#define CHG_STAT_TSD_FAST	0x21
+#define CHG_STAT_TSD_TOPOFF	0x22
+#define CHG_STAT_BAT_ERR	0x7f
+
+static const char *bd70528_charger_model = "BD70528";
+static const char *bd70528_charger_manufacturer = "ROHM Semiconductors";
+
+#define BD_ERR_IRQ_HND(_name_, _wrn_)					\
+static irqreturn_t bd0528_##_name_##_interrupt(int irq, void *arg)	\
+{									\
+	struct power_supply *psy = (struct power_supply *)arg;		\
+									\
+	power_supply_changed(psy);					\
+	dev_err(&psy->dev, (_wrn_));					\
+									\
+	return IRQ_HANDLED;						\
+}
+
+#define BD_INFO_IRQ_HND(_name_, _wrn_)					\
+static irqreturn_t bd0528_##_name_##_interrupt(int irq, void *arg)	\
+{									\
+	struct power_supply *psy = (struct power_supply *)arg;		\
+									\
+	power_supply_changed(psy);					\
+	dev_dbg(&psy->dev, (_wrn_));					\
+									\
+	return IRQ_HANDLED;						\
+}
+
+#define BD_IRQ_HND(_name_) bd0528_##_name_##_interrupt
+
+BD_ERR_IRQ_HND(BAT_OV_DET, "Battery overvoltage detected\n");
+BD_ERR_IRQ_HND(DBAT_DET, "Dead battery detected\n");
+BD_ERR_IRQ_HND(COLD_DET, "Battery cold\n");
+BD_ERR_IRQ_HND(HOT_DET, "Battery hot\n");
+BD_ERR_IRQ_HND(CHG_TSD, "Charger thermal shutdown\n");
+BD_ERR_IRQ_HND(DCIN2_OV_DET, "DCIN2 overvoltage detected\n");
+
+BD_INFO_IRQ_HND(BAT_OV_RES, "Battery voltage back to normal\n");
+BD_INFO_IRQ_HND(COLD_RES, "Battery temperature back to normal\n");
+BD_INFO_IRQ_HND(HOT_RES, "Battery temperature back to normal\n");
+BD_INFO_IRQ_HND(BAT_RMV, "Battery removed\n");
+BD_INFO_IRQ_HND(BAT_DET, "Battery detected\n");
+BD_INFO_IRQ_HND(DCIN2_OV_RES, "DCIN2 voltage back to normal\n");
+BD_INFO_IRQ_HND(DCIN2_RMV, "DCIN2 removed\n");
+BD_INFO_IRQ_HND(DCIN2_DET, "DCIN2 detected\n");
+BD_INFO_IRQ_HND(DCIN1_RMV, "DCIN1 removed\n");
+BD_INFO_IRQ_HND(DCIN1_DET, "DCIN1 detected\n");
+
+struct irq_name_pair {
+	const char *n;
+	irqreturn_t (*h)(int irq, void *arg);
+};
+
+static int bd70528_get_irqs(struct platform_device *pdev,
+			    struct bd70528 *bd70528)
+{
+	int irq, i, ret;
+	unsigned int mask;
+	struct irq_name_pair bd70528_chg_irqs[] = {
+		{ .n = "bd70528-bat-ov-res", .h = BD_IRQ_HND(BAT_OV_RES) },
+		{ .n = "bd70528-bat-ov-det", .h = BD_IRQ_HND(BAT_OV_DET) },
+		{ .n = "bd70528-bat-dead", .h = BD_IRQ_HND(DBAT_DET) },
+		{ .n = "bd70528-bat-warmed", .h = BD_IRQ_HND(COLD_RES) },
+		{ .n = "bd70528-bat-cold", .h = BD_IRQ_HND(COLD_DET) },
+		{ .n = "bd70528-bat-cooled", .h = BD_IRQ_HND(HOT_RES) },
+		{ .n = "bd70528-bat-hot", .h = BD_IRQ_HND(HOT_DET) },
+		{ .n = "bd70528-chg-tshd", .h = BD_IRQ_HND(CHG_TSD) },
+		{ .n = "bd70528-bat-removed", .h = BD_IRQ_HND(BAT_RMV) },
+		{ .n = "bd70528-bat-detected", .h = BD_IRQ_HND(BAT_DET) },
+		{ .n = "bd70528-dcin2-ov-res", .h = BD_IRQ_HND(DCIN2_OV_RES) },
+		{ .n = "bd70528-dcin2-ov-det", .h = BD_IRQ_HND(DCIN2_OV_DET) },
+		{ .n = "bd70528-dcin2-removed", .h = BD_IRQ_HND(DCIN2_RMV) },
+		{ .n = "bd70528-dcin2-detected", .h = BD_IRQ_HND(DCIN2_DET) },
+		{ .n = "bd70528-dcin1-removed", .h = BD_IRQ_HND(DCIN1_RMV) },
+		{ .n = "bd70528-dcin1-detected", .h = BD_IRQ_HND(DCIN1_DET) },
+	};
+
+	for (i = 0; i < ARRAY_SIZE(bd70528_chg_irqs); i++) {
+		irq = platform_get_irq_byname(pdev, bd70528_chg_irqs[i].n);
+		if (irq < 0) {
+			dev_err(&pdev->dev, "Bad IRQ information for %s (%d)\n",
+				bd70528_chg_irqs[i].n, irq);
+			return irq;
+		}
+		ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
+						bd70528_chg_irqs[i].h,
+						IRQF_ONESHOT,
+						bd70528_chg_irqs[i].n, bd70528);
+
+		if (ret)
+			return ret;
+	}
+	/*
+	 * BD70528 irq controller is not touching the main mask register.
+	 * So enable the charger block interrupts at main level. We can just
+	 * leave them enabled as irq-controller should disable irqs
+	 * from sub-registers when IRQ is disabled or freed.
+	 */
+	mask = BD70528_REG_INT_BAT1_MASK | BD70528_REG_INT_BAT2_MASK;
+	ret = regmap_update_bits(bd70528->chip.regmap,
+				 BD70528_REG_INT_MAIN_MASK, mask, 0);
+	if (ret)
+		dev_err(&pdev->dev, "Failed to enable charger IRQs\n");
+
+	return ret;
+}
+
+static int bd70528_get_charger_status(struct bd70528 *bd70528, int *val)
+{
+	int ret;
+	unsigned int v;
+
+	ret = regmap_read(bd70528->chip.regmap, BD70528_REG_CHG_CURR_STAT, &v);
+	if (ret) {
+		dev_err(bd70528->chip.dev, "Charger state read failure %d\n",
+			ret);
+		return ret;
+	}
+
+	switch (v & BD70528_MASK_CHG_STAT) {
+	case CHG_STAT_SUSPEND:
+	/* Maybe we should check the CHG_TTRI_EN? */
+	case CHG_STAT_OTP_TRICKLE:
+	case CHG_STAT_OTP_FAST:
+	case CHG_STAT_OTP_DONE:
+	case CHG_STAT_TSD_TRICKLE:
+	case CHG_STAT_TSD_FAST:
+	case CHG_STAT_TSD_TOPOFF:
+	case CHG_STAT_BAT_ERR:
+		*val = POWER_SUPPLY_STATUS_NOT_CHARGING;
+		break;
+	case CHG_STAT_DONE:
+		*val = POWER_SUPPLY_STATUS_FULL;
+		break;
+	case CHG_STAT_TRICKLE:
+	case CHG_STAT_FAST:
+	case CHG_STAT_TOPOFF:
+		*val = POWER_SUPPLY_STATUS_CHARGING;
+		break;
+	default:
+		*val = POWER_SUPPLY_STATUS_UNKNOWN;
+		break;
+	}
+
+	return 0;
+}
+
+static int bd70528_get_charge_type(struct bd70528 *bd70528, int *val)
+{
+	int ret;
+	unsigned int v;
+
+	ret = regmap_read(bd70528->chip.regmap, BD70528_REG_CHG_CURR_STAT, &v);
+	if (ret) {
+		dev_err(bd70528->chip.dev, "Charger state read failure %d\n",
+			ret);
+		return ret;
+	}
+
+	switch (v & BD70528_MASK_CHG_STAT) {
+	case CHG_STAT_TRICKLE:
+		*val = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
+		break;
+	case CHG_STAT_FAST:
+	case CHG_STAT_TOPOFF:
+		*val = POWER_SUPPLY_CHARGE_TYPE_FAST;
+		break;
+	case CHG_STAT_DONE:
+	case CHG_STAT_SUSPEND:
+	/* Maybe we should check the CHG_TTRI_EN? */
+	case CHG_STAT_OTP_TRICKLE:
+	case CHG_STAT_OTP_FAST:
+	case CHG_STAT_OTP_DONE:
+	case CHG_STAT_TSD_TRICKLE:
+	case CHG_STAT_TSD_FAST:
+	case CHG_STAT_TSD_TOPOFF:
+	case CHG_STAT_BAT_ERR:
+		*val = POWER_SUPPLY_CHARGE_TYPE_NONE;
+		break;
+	default:
+		*val = POWER_SUPPLY_CHARGE_TYPE_UNKNOWN;
+		break;
+	}
+
+	return 0;
+}
+
+static int bd70528_get_battery_health(struct bd70528 *bd70528, int *val)
+{
+	int ret;
+	unsigned int v;
+
+	ret = regmap_read(bd70528->chip.regmap, BD70528_REG_CHG_BAT_STAT, &v);
+	if (ret) {
+		dev_err(bd70528->chip.dev, "Battery state read failure %d\n",
+			ret);
+		return ret;
+	}
+	/* No battery? */
+	if (!(v & BD70528_MASK_CHG_BAT_DETECT))
+		*val = POWER_SUPPLY_HEALTH_DEAD;
+	else if (v & BD70528_MASK_CHG_BAT_OVERVOLT)
+		*val = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
+	else if (v & BD70528_MASK_CHG_BAT_TIMER)
+		*val = POWER_SUPPLY_HEALTH_SAFETY_TIMER_EXPIRE;
+	else
+		*val = POWER_SUPPLY_HEALTH_GOOD;
+
+	return 0;
+}
+
+static int bd70528_get_online(struct bd70528 *bd70528, int *val)
+{
+	int ret;
+	unsigned int v;
+
+	ret = regmap_read(bd70528->chip.regmap, BD70528_REG_CHG_IN_STAT, &v);
+	if (ret) {
+		dev_err(bd70528->chip.dev, "DC1 IN state read failure %d\n",
+			ret);
+		return ret;
+	}
+
+	*val = (v & BD70528_MASK_CHG_DCIN1_UVLO) ? 1 : 0;
+
+	return 0;
+}
+
+static int bd70528_get_present(struct bd70528 *bd70528, int *val)
+{
+	int ret;
+	unsigned int v;
+
+	ret = regmap_read(bd70528->chip.regmap, BD70528_REG_CHG_BAT_STAT, &v);
+	if (ret) {
+		dev_err(bd70528->chip.dev, "Battery state read failure %d\n",
+			ret);
+		return ret;
+	}
+
+	*val = (v & BD70528_MASK_CHG_BAT_DETECT) ? 1 : 0;
+
+	return 0;
+}
+
+struct linear_range {
+	int min;
+	int step;
+	int vals;
+	int low_sel;
+};
+
+struct linear_range current_limit_ranges[] = {
+	{
+		.min = 5,
+		.step = 1,
+		.vals = 36,
+		.low_sel = 0,
+	},
+	{
+		.min = 40,
+		.step = 5,
+		.vals = 5,
+		.low_sel = 0x23,
+	},
+	{
+		.min = 60,
+		.step = 20,
+		.vals = 8,
+		.low_sel = 0x27,
+	},
+	{
+		.min = 200,
+		.step = 50,
+		.vals = 7,
+		.low_sel = 0x2e,
+	}
+};
+
+/*
+ * BD70528 would support setting and getting own charge current/
+ * voltage for low temperatures. The driver currently only reads
+ * the charge current at room temperature. We do set both though.
+ */
+struct linear_range warm_charge_curr[] = {
+	{
+		.min = 10,
+		.step = 10,
+		.vals = 20,
+		.low_sel = 0,
+	},
+	{
+		.min = 200,
+		.step = 25,
+		.vals = 13,
+		.low_sel = 0x13,
+	},
+};
+
+/*
+ * Cold charge current selectors are identical to warm charge current
+ * selectors. The difference is that only smaller currents are available
+ * at cold charge range.
+ */
+#define MAX_COLD_CHG_CURR_SEL 0x15
+#define MAX_WARM_CHG_CURR_SEL 0x1f
+#define MIN_CHG_CURR_SEL 0x0
+
+static int find_value_for_selector_low(struct linear_range *r, int selectors,
+				       unsigned int sel, unsigned int *val)
+{
+	int i;
+
+	for (i = 0; i < selectors; i++) {
+		if (r[i].low_sel <= sel && r[i].low_sel + r[i].vals >= sel) {
+			*val = r[i].min + (sel - r[i].low_sel) * r[i].step;
+			return 0;
+		}
+
+	}
+	return -EINVAL;
+}
+
+/*
+ * For BD70528 voltage/current limits we happily accept any value which
+ * belongs the range. We could check if value matching the selector is
+ * desired by computing the range min + (sel - sel_low) * range step - but
+ * I guess it is enough if we use voltage/current which is closest (below)
+ * the requested?
+ */
+static int find_selector_for_value_low(struct linear_range *r, int selectors,
+				       unsigned int val, unsigned int *sel,
+				       bool *found)
+{
+	int i;
+	int ret = -EINVAL;
+
+	*found = false;
+	for (i = 0; i < selectors; i++) {
+		if (r[i].min <= val) {
+			if (r[i].min + r[i].step * r[i].vals >= val) {
+				*found = true;
+				*sel = r[i].low_sel + (val - r[i].min) /
+				       r[i].step;
+				ret = 0;
+				break;
+			}
+			/*
+			 * If the range max is smaller than requested
+			 * we can set the max supported value from range
+			 */
+			*sel = r[i].low_sel + r[i].vals;
+			ret = 0;
+		}
+	}
+	return ret;
+}
+
+static int get_charge_current(struct bd70528 *bd70528, int *ma)
+{
+	unsigned int sel;
+	int ret;
+
+	ret = regmap_read(bd70528->chip.regmap, BD70528_REG_CHG_CHG_CURR_WARM,
+			  &sel);
+	if (ret) {
+		dev_err(bd70528->chip.dev,
+			"Charge current reading failed (%d)\n", ret);
+		return ret;
+	}
+
+	sel &= BD70528_MASK_CHG_CHG_CURR;
+
+	ret = find_value_for_selector_low(&warm_charge_curr[0],
+					  ARRAY_SIZE(warm_charge_curr), sel,
+					  ma);
+	if (ret) {
+		dev_err(bd70528->chip.dev,
+			"Unknown charge current value 0x%x\n",
+			sel);
+	}
+
+	return ret;
+}
+
+static int get_current_limit(struct bd70528 *bd70528, int *ma)
+{
+	unsigned int sel;
+	int ret;
+
+	ret = regmap_read(bd70528->chip.regmap, BD70528_REG_CHG_DCIN_ILIM,
+			  &sel);
+
+	if (ret) {
+		dev_err(bd70528->chip.dev,
+			"Input current limit reading failed (%d)\n", ret);
+		return ret;
+	}
+
+	sel &= BD70528_MASK_CHG_DCIN_ILIM;
+
+	ret = find_value_for_selector_low(&current_limit_ranges[0],
+					  ARRAY_SIZE(current_limit_ranges), sel,
+					  ma);
+
+	if (ret) {
+		/* Unspecified values mean 500 mA */
+		*ma = 500;
+	}
+	return 0;
+}
+
+static enum power_supply_property bd70528_charger_props[] = {
+	POWER_SUPPLY_PROP_STATUS,
+	POWER_SUPPLY_PROP_CHARGE_TYPE,
+	POWER_SUPPLY_PROP_HEALTH,
+	POWER_SUPPLY_PROP_PRESENT,
+	POWER_SUPPLY_PROP_ONLINE,
+	POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT,
+	POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT,
+	POWER_SUPPLY_PROP_MODEL_NAME,
+	POWER_SUPPLY_PROP_MANUFACTURER,
+};
+
+static int bd70528_charger_get_property(struct power_supply *psy,
+					enum power_supply_property psp,
+					union power_supply_propval *val)
+{
+	struct bd70528 *bd70528 = power_supply_get_drvdata(psy);
+	int ret = 0;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_STATUS:
+		return bd70528_get_charger_status(bd70528, &val->intval);
+	case POWER_SUPPLY_PROP_CHARGE_TYPE:
+		return bd70528_get_charge_type(bd70528, &val->intval);
+	case POWER_SUPPLY_PROP_HEALTH:
+		return bd70528_get_battery_health(bd70528, &val->intval);
+	case POWER_SUPPLY_PROP_PRESENT:
+		return bd70528_get_present(bd70528, &val->intval);
+	case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
+		ret = get_current_limit(bd70528, &val->intval);
+		val->intval *= 1000;
+		return ret;
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
+		ret = get_charge_current(bd70528, &val->intval);
+		val->intval *= 1000;
+		return ret;
+	case POWER_SUPPLY_PROP_ONLINE:
+		return bd70528_get_online(bd70528, &val->intval);
+	case POWER_SUPPLY_PROP_MODEL_NAME:
+		val->strval = bd70528_charger_model;
+		return 0;
+	case POWER_SUPPLY_PROP_MANUFACTURER:
+		val->strval = bd70528_charger_manufacturer;
+		return 0;
+	default:
+		break;
+	}
+
+	return -EINVAL;
+}
+
+static int bd70528_prop_is_writable(struct power_supply *psy,
+				    enum power_supply_property psp)
+{
+	switch (psp) {
+	case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
+		return 1;
+	default:
+		break;
+	}
+	return 0;
+}
+
+
+
+static int set_charge_current(struct bd70528 *bd70528, int ma)
+{
+	unsigned int reg;
+	int ret = 0, tmpret;
+	bool found;
+
+	if (ma > 500) {
+		dev_warn(bd70528->chip.dev,
+			 "Requested charge current %u exceed maximum (500mA)\n",
+			 ma);
+		reg = MAX_WARM_CHG_CURR_SEL;
+		goto set;
+	}
+	if (ma < 10) {
+		dev_err(bd70528->chip.dev,
+			"Requested charge current %u smaller than min (10mA)\n",
+			 ma);
+		reg = MIN_CHG_CURR_SEL;
+		ret = -EINVAL;
+		goto set;
+	}
+
+	ret = find_selector_for_value_low(&warm_charge_curr[0],
+					  ARRAY_SIZE(warm_charge_curr), ma,
+					  &reg, &found);
+
+	if (!found) {
+		/* There was a gap in supported values and we hit it */
+		dev_warn(bd70528->chip.dev,
+			 "Unsupported charge current %u mA\n", ma);
+	}
+set:
+
+	tmpret = regmap_update_bits(bd70528->chip.regmap,
+				    BD70528_REG_CHG_CHG_CURR_WARM,
+				    BD70528_MASK_CHG_CHG_CURR, reg);
+	if (tmpret)
+		dev_err(bd70528->chip.dev,
+			"Charge current write failure (%d)\n", tmpret);
+
+	if (reg > MAX_COLD_CHG_CURR_SEL)
+		reg = MAX_COLD_CHG_CURR_SEL;
+
+	if (!tmpret)
+		tmpret = regmap_update_bits(bd70528->chip.regmap,
+					    BD70528_REG_CHG_CHG_CURR_COLD,
+					    BD70528_MASK_CHG_CHG_CURR, reg);
+
+	if (!ret)
+		ret = tmpret;
+
+	return ret;
+}
+
+#define MAX_CURR_LIMIT_SEL 0x34
+#define MIN_CURR_LIMIT_SEL 0x0
+
+static int set_current_limit(struct bd70528 *bd70528, int ma)
+{
+	unsigned int reg;
+	int ret = 0, tmpret;
+	bool found;
+
+	if (ma > 500) {
+		dev_warn(bd70528->chip.dev,
+			 "Requested current limit %u exceed maximum (500mA)\n",
+			 ma);
+		reg = MAX_CURR_LIMIT_SEL;
+		goto set;
+	}
+	if (ma < 5) {
+		dev_err(bd70528->chip.dev,
+			"Requested current limit %u smaller than min (5mA)\n",
+			ma);
+		reg = MIN_CURR_LIMIT_SEL;
+		ret = -EINVAL;
+		goto set;
+	}
+
+	ret = find_selector_for_value_low(&current_limit_ranges[0],
+					  ARRAY_SIZE(current_limit_ranges), ma,
+					  &reg, &found);
+	if (!found) {
+		/* There was a gap in supported values and we hit it ?*/
+		dev_warn(bd70528->chip.dev, "Unsupported current limit %umA\n",
+			 ma);
+	}
+
+set:
+	tmpret = regmap_update_bits(bd70528->chip.regmap,
+				    BD70528_REG_CHG_DCIN_ILIM,
+				    BD70528_MASK_CHG_DCIN_ILIM, reg);
+
+	if (!ret)
+		ret = tmpret;
+
+	return ret;
+}
+
+static int bd70528_charger_set_property(struct power_supply *psy,
+					enum power_supply_property psp,
+					const union power_supply_propval *val)
+{
+	struct bd70528 *bd70528 = power_supply_get_drvdata(psy);
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
+		return set_current_limit(bd70528, val->intval / 1000);
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
+		return set_charge_current(bd70528, val->intval / 1000);
+	default:
+		break;
+	}
+	return -EINVAL;
+}
+
+static const struct power_supply_desc bd70528_charger_desc = {
+	.name		= "bd70528-charger",
+	.type		= POWER_SUPPLY_TYPE_BATTERY,
+	.properties	= bd70528_charger_props,
+	.num_properties	= ARRAY_SIZE(bd70528_charger_props),
+	.get_property	= bd70528_charger_get_property,
+	.set_property	= bd70528_charger_set_property,
+	.property_is_writeable	= bd70528_prop_is_writable,
+};
+
+static int bd70528_power_probe(struct platform_device *pdev)
+{
+	struct bd70528 *bd70528, *tmp;
+	struct power_supply *psy;
+	struct power_supply_config cfg = {};
+
+	tmp = dev_get_drvdata(pdev->dev.parent);
+	if (!tmp) {
+		dev_err(&pdev->dev, "No MFD driver data\n");
+		return -EINVAL;
+	}
+	bd70528 = devm_kzalloc(&pdev->dev, sizeof(*bd70528), GFP_KERNEL);
+	if (!bd70528)
+		return -ENOMEM;
+	*bd70528 = *tmp;
+	bd70528->chip.dev = &pdev->dev;
+
+	platform_set_drvdata(pdev, bd70528);
+	cfg.drv_data = bd70528;
+	cfg.of_node = pdev->dev.parent->of_node;
+
+	psy = devm_power_supply_register(&pdev->dev, &bd70528_charger_desc,
+					 &cfg);
+	if (IS_ERR(psy)) {
+		dev_err(&pdev->dev, "failed: power supply register\n");
+		return PTR_ERR(psy);
+	}
+
+	return bd70528_get_irqs(pdev, bd70528);
+}
+
+static struct platform_driver bd70528_power = {
+	.driver = {
+		.name = "bd70528-power"
+	},
+	.probe = bd70528_power_probe,
+};
+
+module_platform_driver(bd70528_power);
+
+MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>");
+MODULE_DESCRIPTION("BD70528 power-supply driver");
+MODULE_LICENSE("GPL");