diff mbox series

[RESEND,3/4,v7] power: supply: Add charger driver for Rockchip RK817

Message ID 20220721161718.29800-4-macroalpha82@gmail.com (mailing list archive)
State Superseded
Headers show
Series power: supply: Add Support for RK817 Charger | expand

Commit Message

Chris Morgan July 21, 2022, 4:17 p.m. UTC
From: Chris Morgan <macromorgan@hotmail.com>

Add support for the Rockchip rk817 battery charger integrated into the
rk817 PMIC.

Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
Signed-off-by: Maya Matuszczyk <maccraft123mc@gmail.com>
---
 drivers/power/supply/Kconfig         |    6 +
 drivers/power/supply/Makefile        |    1 +
 drivers/power/supply/rk817_charger.c | 1157 ++++++++++++++++++++++++++
 3 files changed, 1164 insertions(+)
 create mode 100644 drivers/power/supply/rk817_charger.c

Comments

kernel test robot July 24, 2022, 2:58 p.m. UTC | #1
Hi Chris,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on lee-mfd/for-mfd-next]
[also build test WARNING on sre-power-supply/for-next rockchip/for-next linus/master v5.19-rc7 next-20220722]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Chris-Morgan/power-supply-Add-Support-for-RK817-Charger/20220722-002431
base:   https://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd.git for-mfd-next
config: parisc-allmodconfig (https://download.01.org/0day-ci/archive/20220724/202207242227.mttUkfTB-lkp@intel.com/config)
compiler: hppa-linux-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/intel-lab-lkp/linux/commit/008e6f0d590e275cbb56d4506b5638156506dd40
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Chris-Morgan/power-supply-Add-Support-for-RK817-Charger/20220722-002431
        git checkout 008e6f0d590e275cbb56d4506b5638156506dd40
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=parisc SHELL=/bin/bash drivers/power/supply/

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

   drivers/power/supply/rk817_charger.c: In function 'rk817_read_or_set_full_charge_on_boot':
>> drivers/power/supply/rk817_charger.c:701:33: warning: variable 'soc_tmp3' set but not used [-Wunused-but-set-variable]
     701 |         int soc_tmp1, soc_tmp2, soc_tmp3;
         |                                 ^~~~~~~~
>> drivers/power/supply/rk817_charger.c:701:23: warning: variable 'soc_tmp2' set but not used [-Wunused-but-set-variable]
     701 |         int soc_tmp1, soc_tmp2, soc_tmp3;
         |                       ^~~~~~~~
>> drivers/power/supply/rk817_charger.c:701:13: warning: variable 'soc_tmp1' set but not used [-Wunused-but-set-variable]
     701 |         int soc_tmp1, soc_tmp2, soc_tmp3;
         |             ^~~~~~~~


vim +/soc_tmp3 +701 drivers/power/supply/rk817_charger.c

   692	
   693	static int
   694	rk817_read_or_set_full_charge_on_boot(struct rk817_charger *charger,
   695					struct power_supply_battery_info *bat_info)
   696	{
   697		struct rk808 *rk808 = charger->rk808;
   698		u8 bulk_reg[4];
   699		u32 boot_voltage, boot_charge_mah, tmp;
   700		int ret, reg, off_time;
 > 701		int soc_tmp1, soc_tmp2, soc_tmp3;
   702		bool first_boot;
   703	
   704		/* Check if the battery is uninitalized. If it is, the columb counter
   705		 * needs to be set up.
   706		 */
   707		ret = regmap_read(rk808->regmap, RK817_GAS_GAUGE_GG_STS, &reg);
   708		if (ret < 0)
   709			return ret;
   710		first_boot = reg & RK817_BAT_CON;
   711		/* If the battery is uninitialized, use the poweron voltage and an ocv
   712		 * lookup to guess our charge. The number won't be very accurate until
   713		 * we hit either our minimum voltage (0%) or full charge (100%).
   714		 */
   715		if (first_boot) {
   716			regmap_bulk_read(rk808->regmap, RK817_GAS_GAUGE_PWRON_VOL_H,
   717					 bulk_reg, 2);
   718			tmp = get_unaligned_be16(bulk_reg);
   719			boot_voltage = (charger->voltage_k * tmp) +
   720					1000 * charger->voltage_b;
   721			/* Since only implementation has no working thermistor, assume
   722			 * 20C for OCV lookup. If lookup fails, report error with OCV
   723			 * table.
   724			 */
   725			charger->soc = power_supply_batinfo_ocv2cap(bat_info,
   726								    boot_voltage,
   727								    20) * 1000;
   728			if (charger->soc < 0)
   729				charger->soc = 0;
   730	
   731			/* Guess that full charge capacity is the design capacity */
   732			charger->fcc_mah = charger->bat_charge_full_design_uah / 1000;
   733			/* Set battery as "set up". BSP driver uses this value even
   734			 * though datasheet claims it's a read-only value.
   735			 */
   736			regmap_write_bits(rk808->regmap, RK817_GAS_GAUGE_GG_STS,
   737					  RK817_BAT_CON, 0);
   738			/* Save nvram values */
   739			ret = rk817_record_battery_nvram_values(charger);
   740			if (ret < 0)
   741				return ret;
   742		} else {
   743			ret = rk817_read_battery_nvram_values(charger);
   744			if (ret < 0)
   745				return ret;
   746	
   747			regmap_bulk_read(rk808->regmap, RK817_GAS_GAUGE_Q_PRES_H3,
   748					 bulk_reg, 4);
   749			tmp = get_unaligned_be32(bulk_reg);
   750			if (tmp < 0)
   751				tmp = 0;
   752			boot_charge_mah = ADC_TO_CHARGE_UAH(tmp,
   753							    charger->res_div) / 1000;
   754			/* Check if the columb counter has been off for more than 300
   755			 * minutes as it tends to drift downward. If so, re-init soc
   756			 * with the boot voltage instead. Note the unit values for the
   757			 * OFF_CNT register appear to be in decaminutes and stops
   758			 * counting at 2550 (0xFF) minutes. BSP kernel used OCV, but
   759			 * for me occasionally that would show invalid values. Boot
   760			 * voltage is only accurate for me on first poweron (not
   761			 * reboots), but we shouldn't ever encounter an OFF_CNT more
   762			 * than 0 on a reboot anyway.
   763			 */
   764			regmap_read(rk808->regmap, RK817_GAS_GAUGE_OFF_CNT, &off_time);
   765			if (off_time >= 30) {
   766				regmap_bulk_read(rk808->regmap,
   767						 RK817_GAS_GAUGE_PWRON_VOL_H,
   768						 bulk_reg, 2);
   769				tmp = get_unaligned_be16(bulk_reg);
   770				boot_voltage = (charger->voltage_k * tmp) +
   771						1000 * charger->voltage_b;
   772				charger->soc =
   773					power_supply_batinfo_ocv2cap(bat_info,
   774								     boot_voltage,
   775								     20) * 1000;
   776			} else {
   777				charger->soc = (boot_charge_mah * 1000 * 100 /
   778						charger->fcc_mah);
   779			}
   780		}
   781	
   782		regmap_bulk_read(rk808->regmap, RK817_GAS_GAUGE_PWRON_VOL_H,
   783				 bulk_reg, 2);
   784		tmp = get_unaligned_be16(bulk_reg);
   785		boot_voltage = (charger->voltage_k * tmp) + 1000 * charger->voltage_b;
   786		soc_tmp1 = power_supply_batinfo_ocv2cap(bat_info,
   787							boot_voltage, 20) * 1000;
   788		regmap_bulk_read(rk808->regmap, RK817_GAS_GAUGE_Q_PRES_H3,
   789				 bulk_reg, 4);
   790		tmp = get_unaligned_be32(bulk_reg);
   791		if (tmp < 0)
   792			tmp = 0;
   793		boot_charge_mah = ADC_TO_CHARGE_UAH(tmp, charger->res_div) / 1000;
   794		soc_tmp2 = (boot_charge_mah * 1000 * 100 / charger->fcc_mah);
   795		regmap_bulk_read(rk808->regmap, RK817_GAS_GAUGE_OCV_VOL_H,
   796				 bulk_reg, 2);
   797		tmp = get_unaligned_be16(bulk_reg);
   798		boot_voltage = (charger->voltage_k * tmp) + 1000 * charger->voltage_b;
   799		soc_tmp3 = power_supply_batinfo_ocv2cap(bat_info,
   800							boot_voltage, 20) * 1000;
   801	
   802		/* Now we have our full charge capacity and soc, init the columb
   803		 * counter.
   804		 */
   805		boot_charge_mah = charger->soc * charger->fcc_mah / 100 / 1000;
   806		if (boot_charge_mah > charger->fcc_mah)
   807			boot_charge_mah = charger->fcc_mah;
   808		tmp = CHARGE_TO_ADC(boot_charge_mah, charger->res_div);
   809		put_unaligned_be32(tmp, bulk_reg);
   810		ret = regmap_bulk_write(rk808->regmap, RK817_GAS_GAUGE_Q_INIT_H3,
   811				  bulk_reg, 4);
   812		if (ret < 0)
   813			return ret;
   814	
   815		/* Set QMAX value to max design capacity. */
   816		tmp = CHARGE_TO_ADC((charger->bat_charge_full_design_uah / 1000),
   817				    charger->res_div);
   818		put_unaligned_be32(tmp, bulk_reg);
   819		ret = regmap_bulk_write(rk808->regmap, RK817_GAS_GAUGE_Q_MAX_H3,
   820					bulk_reg, 4);
   821		if (ret < 0)
   822			return ret;
   823	
   824		return 0;
   825	}
   826
Chris Morgan July 29, 2022, 4:28 p.m. UTC | #2
On Sun, Jul 24, 2022 at 10:58:00PM +0800, kernel test robot wrote:
> Hi Chris,
> 
> Thank you for the patch! Perhaps something to improve:

I'm afraid I'm not sure the best way to fix this. The only thing I can
think of is for now the driver should only be for systems with a
Rockchip RK817 PMIC (to my knowledge only ARM based systems from
Rockchip), but it looks like the arch was set as parisc. Even still,
as long as some of the functions ahead of it don't error out each
of those variables should be used. Is there a way to confirm these
warnings?

Thank you.

> 
> [auto build test WARNING on lee-mfd/for-mfd-next]
> [also build test WARNING on sre-power-supply/for-next rockchip/for-next linus/master v5.19-rc7 next-20220722]
> [If your patch is applied to the wrong git tree, kindly drop us a note.
> And when submitting patch, we suggest to use '--base' as documented in
> https://git-scm.com/docs/git-format-patch#_base_tree_information]
> 
> url:    https://github.com/intel-lab-lkp/linux/commits/Chris-Morgan/power-supply-Add-Support-for-RK817-Charger/20220722-002431
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd.git for-mfd-next
> config: parisc-allmodconfig (https://download.01.org/0day-ci/archive/20220724/202207242227.mttUkfTB-lkp@intel.com/config)
> compiler: hppa-linux-gcc (GCC) 12.1.0
> reproduce (this is a W=1 build):
>         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         # https://github.com/intel-lab-lkp/linux/commit/008e6f0d590e275cbb56d4506b5638156506dd40
>         git remote add linux-review https://github.com/intel-lab-lkp/linux
>         git fetch --no-tags linux-review Chris-Morgan/power-supply-Add-Support-for-RK817-Charger/20220722-002431
>         git checkout 008e6f0d590e275cbb56d4506b5638156506dd40
>         # save the config file
>         mkdir build_dir && cp config build_dir/.config
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=parisc SHELL=/bin/bash drivers/power/supply/
> 
> If you fix the issue, kindly add following tag where applicable
> Reported-by: kernel test robot <lkp@intel.com>
> 
> All warnings (new ones prefixed by >>):
> 
>    drivers/power/supply/rk817_charger.c: In function 'rk817_read_or_set_full_charge_on_boot':
> >> drivers/power/supply/rk817_charger.c:701:33: warning: variable 'soc_tmp3' set but not used [-Wunused-but-set-variable]
>      701 |         int soc_tmp1, soc_tmp2, soc_tmp3;
>          |                                 ^~~~~~~~
> >> drivers/power/supply/rk817_charger.c:701:23: warning: variable 'soc_tmp2' set but not used [-Wunused-but-set-variable]
>      701 |         int soc_tmp1, soc_tmp2, soc_tmp3;
>          |                       ^~~~~~~~
> >> drivers/power/supply/rk817_charger.c:701:13: warning: variable 'soc_tmp1' set but not used [-Wunused-but-set-variable]
>      701 |         int soc_tmp1, soc_tmp2, soc_tmp3;
>          |             ^~~~~~~~
> 
> 
> vim +/soc_tmp3 +701 drivers/power/supply/rk817_charger.c
> 
>    692	
>    693	static int
>    694	rk817_read_or_set_full_charge_on_boot(struct rk817_charger *charger,
>    695					struct power_supply_battery_info *bat_info)
>    696	{
>    697		struct rk808 *rk808 = charger->rk808;
>    698		u8 bulk_reg[4];
>    699		u32 boot_voltage, boot_charge_mah, tmp;
>    700		int ret, reg, off_time;
>  > 701		int soc_tmp1, soc_tmp2, soc_tmp3;
>    702		bool first_boot;
>    703	
>    704		/* Check if the battery is uninitalized. If it is, the columb counter
>    705		 * needs to be set up.
>    706		 */
>    707		ret = regmap_read(rk808->regmap, RK817_GAS_GAUGE_GG_STS, &reg);
>    708		if (ret < 0)
>    709			return ret;
>    710		first_boot = reg & RK817_BAT_CON;
>    711		/* If the battery is uninitialized, use the poweron voltage and an ocv
>    712		 * lookup to guess our charge. The number won't be very accurate until
>    713		 * we hit either our minimum voltage (0%) or full charge (100%).
>    714		 */
>    715		if (first_boot) {
>    716			regmap_bulk_read(rk808->regmap, RK817_GAS_GAUGE_PWRON_VOL_H,
>    717					 bulk_reg, 2);
>    718			tmp = get_unaligned_be16(bulk_reg);
>    719			boot_voltage = (charger->voltage_k * tmp) +
>    720					1000 * charger->voltage_b;
>    721			/* Since only implementation has no working thermistor, assume
>    722			 * 20C for OCV lookup. If lookup fails, report error with OCV
>    723			 * table.
>    724			 */
>    725			charger->soc = power_supply_batinfo_ocv2cap(bat_info,
>    726								    boot_voltage,
>    727								    20) * 1000;
>    728			if (charger->soc < 0)
>    729				charger->soc = 0;
>    730	
>    731			/* Guess that full charge capacity is the design capacity */
>    732			charger->fcc_mah = charger->bat_charge_full_design_uah / 1000;
>    733			/* Set battery as "set up". BSP driver uses this value even
>    734			 * though datasheet claims it's a read-only value.
>    735			 */
>    736			regmap_write_bits(rk808->regmap, RK817_GAS_GAUGE_GG_STS,
>    737					  RK817_BAT_CON, 0);
>    738			/* Save nvram values */
>    739			ret = rk817_record_battery_nvram_values(charger);
>    740			if (ret < 0)
>    741				return ret;
>    742		} else {
>    743			ret = rk817_read_battery_nvram_values(charger);
>    744			if (ret < 0)
>    745				return ret;
>    746	
>    747			regmap_bulk_read(rk808->regmap, RK817_GAS_GAUGE_Q_PRES_H3,
>    748					 bulk_reg, 4);
>    749			tmp = get_unaligned_be32(bulk_reg);
>    750			if (tmp < 0)
>    751				tmp = 0;
>    752			boot_charge_mah = ADC_TO_CHARGE_UAH(tmp,
>    753							    charger->res_div) / 1000;
>    754			/* Check if the columb counter has been off for more than 300
>    755			 * minutes as it tends to drift downward. If so, re-init soc
>    756			 * with the boot voltage instead. Note the unit values for the
>    757			 * OFF_CNT register appear to be in decaminutes and stops
>    758			 * counting at 2550 (0xFF) minutes. BSP kernel used OCV, but
>    759			 * for me occasionally that would show invalid values. Boot
>    760			 * voltage is only accurate for me on first poweron (not
>    761			 * reboots), but we shouldn't ever encounter an OFF_CNT more
>    762			 * than 0 on a reboot anyway.
>    763			 */
>    764			regmap_read(rk808->regmap, RK817_GAS_GAUGE_OFF_CNT, &off_time);
>    765			if (off_time >= 30) {
>    766				regmap_bulk_read(rk808->regmap,
>    767						 RK817_GAS_GAUGE_PWRON_VOL_H,
>    768						 bulk_reg, 2);
>    769				tmp = get_unaligned_be16(bulk_reg);
>    770				boot_voltage = (charger->voltage_k * tmp) +
>    771						1000 * charger->voltage_b;
>    772				charger->soc =
>    773					power_supply_batinfo_ocv2cap(bat_info,
>    774								     boot_voltage,
>    775								     20) * 1000;
>    776			} else {
>    777				charger->soc = (boot_charge_mah * 1000 * 100 /
>    778						charger->fcc_mah);
>    779			}
>    780		}
>    781	
>    782		regmap_bulk_read(rk808->regmap, RK817_GAS_GAUGE_PWRON_VOL_H,
>    783				 bulk_reg, 2);
>    784		tmp = get_unaligned_be16(bulk_reg);
>    785		boot_voltage = (charger->voltage_k * tmp) + 1000 * charger->voltage_b;
>    786		soc_tmp1 = power_supply_batinfo_ocv2cap(bat_info,
>    787							boot_voltage, 20) * 1000;
>    788		regmap_bulk_read(rk808->regmap, RK817_GAS_GAUGE_Q_PRES_H3,
>    789				 bulk_reg, 4);
>    790		tmp = get_unaligned_be32(bulk_reg);
>    791		if (tmp < 0)
>    792			tmp = 0;
>    793		boot_charge_mah = ADC_TO_CHARGE_UAH(tmp, charger->res_div) / 1000;
>    794		soc_tmp2 = (boot_charge_mah * 1000 * 100 / charger->fcc_mah);
>    795		regmap_bulk_read(rk808->regmap, RK817_GAS_GAUGE_OCV_VOL_H,
>    796				 bulk_reg, 2);
>    797		tmp = get_unaligned_be16(bulk_reg);
>    798		boot_voltage = (charger->voltage_k * tmp) + 1000 * charger->voltage_b;
>    799		soc_tmp3 = power_supply_batinfo_ocv2cap(bat_info,
>    800							boot_voltage, 20) * 1000;
>    801	
>    802		/* Now we have our full charge capacity and soc, init the columb
>    803		 * counter.
>    804		 */
>    805		boot_charge_mah = charger->soc * charger->fcc_mah / 100 / 1000;
>    806		if (boot_charge_mah > charger->fcc_mah)
>    807			boot_charge_mah = charger->fcc_mah;
>    808		tmp = CHARGE_TO_ADC(boot_charge_mah, charger->res_div);
>    809		put_unaligned_be32(tmp, bulk_reg);
>    810		ret = regmap_bulk_write(rk808->regmap, RK817_GAS_GAUGE_Q_INIT_H3,
>    811				  bulk_reg, 4);
>    812		if (ret < 0)
>    813			return ret;
>    814	
>    815		/* Set QMAX value to max design capacity. */
>    816		tmp = CHARGE_TO_ADC((charger->bat_charge_full_design_uah / 1000),
>    817				    charger->res_div);
>    818		put_unaligned_be32(tmp, bulk_reg);
>    819		ret = regmap_bulk_write(rk808->regmap, RK817_GAS_GAUGE_Q_MAX_H3,
>    820					bulk_reg, 4);
>    821		if (ret < 0)
>    822			return ret;
>    823	
>    824		return 0;
>    825	}
>    826	
> 
> -- 
> 0-DAY CI Kernel Test Service
> https://01.org/lkp
Krzysztof Kozlowski Aug. 1, 2022, 6:01 p.m. UTC | #3
On 29/07/2022 18:28, Chris Morgan wrote:
> On Sun, Jul 24, 2022 at 10:58:00PM +0800, kernel test robot wrote:
>> Hi Chris,
>>
>> Thank you for the patch! Perhaps something to improve:
> 
> I'm afraid I'm not sure the best way to fix this. The only thing I can
> think of is for now the driver should only be for systems with a
> Rockchip RK817 PMIC (to my knowledge only ARM based systems from
> Rockchip),

Why? We want to compile test everything everywhere,

>  but it looks like the arch was set as parisc. 

The arch itself does not matter unless the actual warning is specific to it.

> Even still,
> as long as some of the functions ahead of it don't error out each
> of those variables should be used. Is there a way to confirm these
> warnings?

Just compile and see by yourself. The error should be visible on
multiple archs. If not, then use parisc. Ubuntu provides most of cross
compilers so it's extra easy to use. The ones not provided by Ubuntu are
also here:
https://mirrors.edge.kernel.org/pub/tools/crosstool/


Best regards,
Krzysztof
diff mbox series

Patch

diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
index 1aa8323ad9f6..56e70a68679a 100644
--- a/drivers/power/supply/Kconfig
+++ b/drivers/power/supply/Kconfig
@@ -708,6 +708,12 @@  config CHARGER_BQ256XX
 	  charge management and system power path management devices for single
 	  cell Li-ion and Li-polymer batteries.
 
+config CHARGER_RK817
+	tristate "Rockchip RK817 PMIC Battery Charger"
+	depends on MFD_RK808
+	help
+	  Say Y to include support for Rockchip RK817 Battery Charger.
+
 config CHARGER_SMB347
 	tristate "Summit Microelectronics SMB3XX Battery Charger"
 	depends on I2C
diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile
index 7f02f36aea55..3040a1de81b8 100644
--- a/drivers/power/supply/Makefile
+++ b/drivers/power/supply/Makefile
@@ -91,6 +91,7 @@  obj-$(CONFIG_CHARGER_BQ2515X)	+= bq2515x_charger.o
 obj-$(CONFIG_CHARGER_BQ25890)	+= bq25890_charger.o
 obj-$(CONFIG_CHARGER_BQ25980)	+= bq25980_charger.o
 obj-$(CONFIG_CHARGER_BQ256XX)	+= bq256xx_charger.o
+obj-$(CONFIG_CHARGER_RK817)	+= rk817_charger.o
 obj-$(CONFIG_CHARGER_SMB347)	+= smb347-charger.o
 obj-$(CONFIG_CHARGER_TPS65090)	+= tps65090-charger.o
 obj-$(CONFIG_CHARGER_TPS65217)	+= tps65217_charger.o
diff --git a/drivers/power/supply/rk817_charger.c b/drivers/power/supply/rk817_charger.c
new file mode 100644
index 000000000000..65a846b7f79e
--- /dev/null
+++ b/drivers/power/supply/rk817_charger.c
@@ -0,0 +1,1157 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Charger Driver for Rockchip rk817
+ *
+ * Copyright (c) 2021
+ *
+ * Authors: Maya Matuszczyk <maccraft123mc@gmail.com>
+ *	    Chris Morgan <macromorgan@hotmail.com>
+ */
+
+#include <linux/mfd/rk808.h>
+#include <linux/irq.h>
+#include <linux/of_gpio.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/power_supply.h>
+#include <asm/unaligned.h>
+
+/* Charging statuses reported by hardware register */
+enum rk817_charge_status {
+	CHRG_OFF,
+	DEAD_CHRG,
+	TRICKLE_CHRG,
+	CC_OR_CV_CHRG,
+	CHARGE_FINISH,
+	USB_OVER_VOL,
+	BAT_TMP_ERR,
+	BAT_TIM_ERR,
+};
+
+/* Max charging current read to/written from hardware register.
+ * Note how highest value corresponding to 0x7 is the lowest
+ * current, this is per the datasheet.
+ */
+enum rk817_chg_cur {
+	CHG_1A,
+	CHG_1_5A,
+	CHG_2A,
+	CHG_2_5A,
+	CHG_2_75A,
+	CHG_3A,
+	CHG_3_5A,
+	CHG_0_5A,
+};
+
+struct rk817_charger {
+	struct device *dev;
+	struct rk808 *rk808;
+
+	struct power_supply *bat_ps;
+	struct power_supply *chg_ps;
+	bool plugged_in;
+	bool battery_present;
+
+	/* voltage_k and voltage_b values are used to calibrate the ADC
+	 * voltage readings. While they are documented in the BSP kernel and
+	 * datasheet as voltage_k and voltage_b, there is no further
+	 * information explaining them in more detail.
+	 */
+
+	uint32_t voltage_k;
+	uint32_t voltage_b;
+
+	/* soc - state of charge - like the BSP this is stored as a percentage,
+	 * to the thousandth. BSP has a display state of charge (dsoc) and a
+	 * remaining state of charge (rsoc). This value will be used for both
+	 * purposes here so we don't do any fancy math to try and "smooth" the
+	 * charge and just report it as it is. Note for example an soc of 100
+	 * is stored as 100000, an soc of 50 is stored as 50000, etc.
+	 */
+	int soc;
+
+	/* Capacity of battery when fully charged, equal or less than design
+	 * capacity depending upon wear. BSP kernel saves to nvram in mAh,
+	 * so this value is in mAh not the standard uAh.
+	 */
+	int fcc_mah;
+
+	/* Calibrate the SOC on a fully charged battery, this way we can use
+	 * the calibrated SOC value to correct for columb counter drift.
+	 */
+	bool soc_cal;
+
+	/* Implementation specific immutable properties from device tree */
+	int res_div;
+	int sleep_enter_current_ua;
+	int sleep_filter_current_ua;
+	int bat_charge_full_design_uah;
+	int bat_voltage_min_design_uv;
+	int bat_voltage_max_design_uv;
+
+	/* Values updated periodically by driver for display. */
+	int charge_now_uah;
+	int volt_avg_uv;
+	int cur_avg_ua;
+	int max_chg_cur_ua;
+	int max_chg_volt_uv;
+	int charge_status;
+	int charger_input_volt_avg_uv;
+
+	/* Work queue to periodically update values. */
+	struct delayed_work work;
+};
+
+/* ADC coefficients extracted from BSP kernel */
+#define ADC_TO_CURRENT(adc_value, res_div)	\
+	(adc_value * 172 / res_div)
+
+#define CURRENT_TO_ADC(current, samp_res)	\
+	(current * samp_res / 172)
+
+#define CHARGE_TO_ADC(capacity, res_div)	\
+	(capacity * res_div * 3600 / 172 * 1000)
+
+#define ADC_TO_CHARGE_UAH(adc_value, res_div)	\
+	(adc_value / 3600 * 172 / res_div)
+
+static u8 rk817_chg_cur_to_reg(u32 chg_cur_ma)
+{
+	if (chg_cur_ma >= 3500)
+		return CHG_3_5A;
+	else if (chg_cur_ma >= 3000)
+		return CHG_3A;
+	else if (chg_cur_ma >= 2750)
+		return CHG_2_75A;
+	else if (chg_cur_ma >= 2500)
+		return CHG_2_5A;
+	else if (chg_cur_ma >= 2000)
+		return CHG_2A;
+	else if (chg_cur_ma >= 1500)
+		return CHG_1_5A;
+	else if (chg_cur_ma >= 1000)
+		return CHG_1A;
+	else if (chg_cur_ma >= 500)
+		return CHG_0_5A;
+	else
+		return -EINVAL;
+}
+
+static int rk817_chg_cur_from_reg(u8 reg)
+{
+	switch (reg) {
+	case CHG_0_5A:
+		return 500000;
+	case CHG_1A:
+		return 1000000;
+	case CHG_1_5A:
+		return 1500000;
+	case CHG_2A:
+		return 2000000;
+	case CHG_2_5A:
+		return 2500000;
+	case CHG_2_75A:
+		return 2750000;
+	case CHG_3A:
+		return 3000000;
+	case CHG_3_5A:
+		return 3500000;
+	default:
+		return -EINVAL;
+	}
+}
+
+static void rk817_bat_calib_vol(struct rk817_charger *charger)
+{
+	uint32_t vcalib0 = 0;
+	uint32_t vcalib1 = 0;
+	u8 bulk_reg[2];
+
+	/* calibrate voltage */
+	regmap_bulk_read(charger->rk808->regmap, RK817_GAS_GAUGE_VCALIB0_H,
+			 bulk_reg, 2);
+	vcalib0 = get_unaligned_be16(bulk_reg);
+
+	regmap_bulk_read(charger->rk808->regmap, RK817_GAS_GAUGE_VCALIB1_H,
+			 bulk_reg, 2);
+	vcalib1 = get_unaligned_be16(bulk_reg);
+
+	/* values were taken from BSP kernel */
+	charger->voltage_k = (4025 - 2300) * 1000 /
+			     ((vcalib1 - vcalib0) ? (vcalib1 - vcalib0) : 1);
+	charger->voltage_b = 4025 - (charger->voltage_k * vcalib1) / 1000;
+}
+
+static void rk817_bat_calib_cur(struct rk817_charger *charger)
+{
+	u8 bulk_reg[2];
+
+	/* calibrate current */
+	regmap_bulk_read(charger->rk808->regmap, RK817_GAS_GAUGE_IOFFSET_H,
+			 bulk_reg, 2);
+	regmap_bulk_write(charger->rk808->regmap, RK817_GAS_GAUGE_CAL_OFFSET_H,
+			  bulk_reg, 2);
+}
+
+/* note that only the fcc_mah is really used by this driver, the other values
+ * are to ensure we can remain backwards compatible with the BSP kernel.
+ */
+static int rk817_record_battery_nvram_values(struct rk817_charger *charger)
+{
+	u8 bulk_reg[3];
+	int ret;
+
+	/* write the soc value to the nvram location used by the BSP kernel
+	 * for the dsoc value.
+	 */
+	put_unaligned_le24(charger->soc, bulk_reg);
+	ret = regmap_bulk_write(charger->rk808->regmap, RK817_GAS_GAUGE_BAT_R1,
+				bulk_reg, 3);
+	if (ret < 0)
+		return ret;
+	/* write the same value to the nvram location used by the BSP kernel
+	 * for the rsoc value.
+	 */
+	put_unaligned_le24(charger->soc, bulk_reg);
+	ret = regmap_bulk_write(charger->rk808->regmap, RK817_GAS_GAUGE_DATA0,
+				bulk_reg, 3);
+	if (ret < 0)
+		return ret;
+	/* write the fcc_mah in mAh, just as the BSP kernel does. */
+	put_unaligned_le24(charger->fcc_mah, bulk_reg);
+	ret = regmap_bulk_write(charger->rk808->regmap, RK817_GAS_GAUGE_DATA3,
+				bulk_reg, 3);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static int rk817_bat_calib_cap(struct rk817_charger *charger)
+{
+	struct rk808 *rk808 = charger->rk808;
+	int tmp, charge_now, charge_now_adc, volt_avg;
+	u8 bulk_reg[4];
+
+	/* Calibrate the soc and fcc on a fully charged battery */
+
+	if (charger->charge_status == CHARGE_FINISH && (!charger->soc_cal)) {
+		/* soc should be 100000 and columb counter should show the full
+		 * charge capacity. Note that if the device is unplugged for a
+		 * period of several days the columb counter will have a large
+		 * margin of error, so setting it back to the full charge on
+		 * a completed charge cycle should correct this (my device was
+		 * showing 33% battery after 3 days unplugged when it should
+		 * have been closer to 95% based on voltage and charge
+		 * current).
+		 */
+
+		charger->soc = 100000;
+		charge_now_adc = CHARGE_TO_ADC(charger->fcc_mah,
+					       charger->res_div);
+		put_unaligned_be32(charge_now_adc, bulk_reg);
+		regmap_bulk_write(rk808->regmap, RK817_GAS_GAUGE_Q_INIT_H3,
+				  bulk_reg, 4);
+
+		charger->soc_cal = 1;
+		dev_dbg(charger->dev,
+			"Fully charged. SOC is %d, full capacity is %d\n",
+			charger->soc, charger->fcc_mah * 1000);
+	}
+
+	/* The columb counter can drift up slightly, so we should correct for
+	 * it. But don't correct it until we're at 100% soc.
+	 */
+	if (charger->charge_status == CHARGE_FINISH && charger->soc_cal) {
+		regmap_bulk_read(rk808->regmap, RK817_GAS_GAUGE_Q_PRES_H3,
+				 bulk_reg, 4);
+		charge_now_adc = get_unaligned_be32(bulk_reg);
+		if (charge_now_adc < 0)
+			return charge_now_adc;
+		charge_now = ADC_TO_CHARGE_UAH(charge_now_adc,
+					       charger->res_div);
+
+		/* Re-init columb counter with updated values to correct drift.
+		 */
+		if (charge_now / 1000 > charger->fcc_mah) {
+			dev_dbg(charger->dev,
+				"Recalibrating columb counter to %d uah\n",
+				charge_now);
+			/* Order of operations matters here to ensure we keep
+			 * enough precision until the last step to keep from
+			 * making needless updates to columb counter.
+			 */
+			charge_now_adc = CHARGE_TO_ADC(charger->fcc_mah,
+					 charger->res_div);
+			put_unaligned_be32(charge_now_adc, bulk_reg);
+			regmap_bulk_write(rk808->regmap,
+					  RK817_GAS_GAUGE_Q_INIT_H3,
+					  bulk_reg, 4);
+		}
+	}
+
+	/* Calibrate the fully charged capacity when we previously had a full
+	 * battery (soc_cal = 1) and are now empty (at or below minimum design
+	 * voltage). If our columb counter is still positive, subtract that
+	 * from our fcc value to get a calibrated fcc, and if our columb
+	 * counter is negative add that to our fcc (but not to exceed our
+	 * design capacity).
+	 */
+	regmap_bulk_read(charger->rk808->regmap, RK817_GAS_GAUGE_BAT_VOL_H,
+			 bulk_reg, 2);
+	tmp = get_unaligned_be16(bulk_reg);
+	volt_avg = (charger->voltage_k * tmp) + 1000 * charger->voltage_b;
+	if (volt_avg <= charger->bat_voltage_min_design_uv &&
+	    charger->soc_cal) {
+		regmap_bulk_read(rk808->regmap, RK817_GAS_GAUGE_Q_PRES_H3,
+				 bulk_reg, 4);
+		charge_now_adc = get_unaligned_be32(bulk_reg);
+		charge_now = ADC_TO_CHARGE_UAH(charge_now_adc,
+					       charger->res_div);
+		/* Note, if charge_now is negative this will add it (what we
+		 * want) and if it's positive this will subtract (also what
+		 * we want).
+		 */
+		charger->fcc_mah = charger->fcc_mah - (charge_now / 1000);
+
+		dev_dbg(charger->dev,
+			"Recalibrating full charge capacity to %d uah\n",
+			charger->fcc_mah * 1000);
+	}
+
+	rk817_record_battery_nvram_values(charger);
+
+	return 0;
+}
+
+static void rk817_read_props(struct rk817_charger *charger)
+{
+	int tmp, reg;
+	u8 bulk_reg[4];
+
+	/* Recalibrate voltage and current readings if we need to BSP does both
+	 * on CUR_CALIB_UPD, ignoring VOL_CALIB_UPD. Curiously enough, both
+	 * documentation and the BSP show that you perform an update if bit 7
+	 * is 1, but you clear the status by writing a 1 to bit 7.
+	 */
+	regmap_read(charger->rk808->regmap, RK817_GAS_GAUGE_ADC_CONFIG1, &reg);
+	if (reg & RK817_VOL_CUR_CALIB_UPD) {
+		rk817_bat_calib_cur(charger);
+		rk817_bat_calib_vol(charger);
+		regmap_write_bits(charger->rk808->regmap,
+				  RK817_GAS_GAUGE_ADC_CONFIG1,
+				  RK817_VOL_CUR_CALIB_UPD,
+				  RK817_VOL_CUR_CALIB_UPD);
+	}
+
+	/* Update reported charge. */
+	regmap_bulk_read(charger->rk808->regmap, RK817_GAS_GAUGE_Q_PRES_H3,
+			 bulk_reg, 4);
+	tmp = get_unaligned_be32(bulk_reg);
+	charger->charge_now_uah = ADC_TO_CHARGE_UAH(tmp, charger->res_div);
+	if (charger->charge_now_uah < 0)
+		charger->charge_now_uah = 0;
+	if (charger->charge_now_uah > charger->fcc_mah * 1000)
+		charger->charge_now_uah = charger->fcc_mah * 1000;
+
+	/* Update soc based on reported charge. */
+	charger->soc = charger->charge_now_uah * 100 / charger->fcc_mah;
+
+	/* Update reported voltage. */
+	regmap_bulk_read(charger->rk808->regmap, RK817_GAS_GAUGE_BAT_VOL_H,
+			 bulk_reg, 2);
+	tmp = get_unaligned_be16(bulk_reg);
+	charger->volt_avg_uv = (charger->voltage_k * tmp) + 1000 *
+				charger->voltage_b;
+
+	/* Update reported current. Note value from registers is a signed 16
+	 * bit int.
+	 */
+	regmap_bulk_read(charger->rk808->regmap, RK817_GAS_GAUGE_BAT_CUR_H,
+			 bulk_reg, 2);
+	tmp = (short int)get_unaligned_be16(bulk_reg);
+	charger->cur_avg_ua = ADC_TO_CURRENT(tmp, charger->res_div);
+
+	/* Update the max charge current. This value shouldn't change, but we
+	 * can read it to report what the PMIC says it is instead of simply
+	 * returning the default value.
+	 */
+	regmap_read(charger->rk808->regmap, RK817_PMIC_CHRG_OUT, &reg);
+	charger->max_chg_cur_ua =
+		rk817_chg_cur_from_reg(reg & RK817_CHRG_CUR_SEL);
+
+	/* Update max charge voltage. Like the max charge current this value
+	 * shouldn't change, but we can report what the PMIC says.
+	 */
+	regmap_read(charger->rk808->regmap, RK817_PMIC_CHRG_OUT, &reg);
+	charger->max_chg_volt_uv = ((((reg & RK817_CHRG_VOL_SEL) >> 4) *
+				    50000) + 4100000);
+
+	/* Check if battery still present. */
+	regmap_read(charger->rk808->regmap, RK817_PMIC_CHRG_STS, &reg);
+	charger->battery_present = (reg & RK817_BAT_EXS);
+
+	/* Get which type of charge we are using (if any). */
+	regmap_read(charger->rk808->regmap, RK817_PMIC_CHRG_STS, &reg);
+	charger->charge_status = (reg >> 4) & 0x07;
+
+	/* Get charger input voltage. Note that on my example hardware (an
+	 * Odroid Go Advance) the voltage of the power connector is measured
+	 * on the register labelled USB in the datasheet; I don't know if this
+	 * is how it is designed or just a quirk of the implementation. I
+	 * believe this will also measure the voltage of the USB output when in
+	 * OTG mode, if that is the case we may need to change this in the
+	 * future to return 0 if the power supply status is offline (I can't
+	 * test this with my current implementation. Also, when the voltage
+	 * should be zero sometimes the ADC still shows a single bit (which
+	 * would register as 20000uv). When this happens set it to 0.
+	 */
+	regmap_bulk_read(charger->rk808->regmap, RK817_GAS_GAUGE_USB_VOL_H,
+			 bulk_reg, 2);
+	reg = get_unaligned_be16(bulk_reg);
+	if (reg > 1) {
+		tmp = ((charger->voltage_k * reg / 1000 + charger->voltage_b) *
+		       60 / 46);
+		charger->charger_input_volt_avg_uv = tmp * 1000;
+	} else {
+		charger->charger_input_volt_avg_uv = 0;
+	}
+
+	/* Calibrate battery capacity and soc. */
+	rk817_bat_calib_cap(charger);
+}
+
+static int rk817_bat_get_prop(struct power_supply *ps,
+		enum power_supply_property prop,
+		union power_supply_propval *val)
+{
+	struct rk817_charger *charger = power_supply_get_drvdata(ps);
+
+	switch (prop) {
+	case POWER_SUPPLY_PROP_PRESENT:
+		val->intval = charger->battery_present;
+		break;
+	case POWER_SUPPLY_PROP_STATUS:
+		if (charger->cur_avg_ua < 0) {
+			val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
+			break;
+		}
+		switch (charger->charge_status) {
+		case CHRG_OFF:
+			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
+			break;
+		/* Dead charge is documented, but not explained. I never
+		 * observed it but assume it's a pre-charge for a dead
+		 * battery.
+		 */
+		case DEAD_CHRG:
+		case TRICKLE_CHRG:
+		case CC_OR_CV_CHRG:
+			val->intval = POWER_SUPPLY_STATUS_CHARGING;
+			break;
+		case CHARGE_FINISH:
+			val->intval = POWER_SUPPLY_STATUS_FULL;
+			break;
+		default:
+			val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
+			return -EINVAL;
+
+		}
+		break;
+	case POWER_SUPPLY_PROP_CHARGE_TYPE:
+		switch (charger->charge_status) {
+		case CHRG_OFF:
+		case CHARGE_FINISH:
+			val->intval = POWER_SUPPLY_CHARGE_TYPE_NONE;
+			break;
+		case TRICKLE_CHRG:
+			val->intval = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
+			break;
+		case DEAD_CHRG:
+		case CC_OR_CV_CHRG:
+			val->intval = POWER_SUPPLY_CHARGE_TYPE_STANDARD;
+			break;
+		default:
+			val->intval = POWER_SUPPLY_CHARGE_TYPE_UNKNOWN;
+			break;
+		}
+		break;
+	case POWER_SUPPLY_PROP_CHARGE_FULL:
+		val->intval = charger->fcc_mah * 1000;
+		break;
+	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
+		val->intval = charger->bat_charge_full_design_uah;
+		break;
+	case POWER_SUPPLY_PROP_CHARGE_EMPTY_DESIGN:
+		val->intval = 0;
+		break;
+	case POWER_SUPPLY_PROP_CHARGE_NOW:
+		val->intval = charger->charge_now_uah;
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
+		val->intval = charger->bat_voltage_min_design_uv;
+		break;
+	case POWER_SUPPLY_PROP_CAPACITY:
+		/* Add 500 so that values like 99999 are 100% not 99%. */
+		val->intval = (charger->soc + 500) / 1000;
+		if (val->intval > 100)
+			val->intval = 100;
+		if (val->intval < 0)
+			val->intval = 0;
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_AVG:
+		val->intval = charger->volt_avg_uv;
+		break;
+	case POWER_SUPPLY_PROP_CURRENT_AVG:
+		val->intval = charger->cur_avg_ua;
+		break;
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
+		val->intval = charger->max_chg_cur_ua;
+		break;
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:
+		val->intval = charger->max_chg_volt_uv;
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
+		val->intval = charger->bat_voltage_max_design_uv;
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static int rk817_chg_get_prop(struct power_supply *ps,
+			      enum power_supply_property prop,
+			      union power_supply_propval *val)
+{
+	struct rk817_charger *charger = power_supply_get_drvdata(ps);
+
+	switch (prop) {
+	case POWER_SUPPLY_PROP_ONLINE:
+		val->intval = charger->plugged_in;
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
+		/* max voltage from datasheet at 5.5v (default 5.0v) */
+		val->intval = 5500000;
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
+		/* min voltage from datasheet at 3.8v (default 5.0v) */
+		val->intval = 3800000;
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_AVG:
+		val->intval = charger->charger_input_volt_avg_uv;
+		break;
+	/* While it's possible that other implementations could use different
+	 * USB types, the current implementation for this PMIC (the Odroid Go
+	 * Advance) only uses a dedicated charging port with no rx/tx lines.
+	 */
+	case POWER_SUPPLY_PROP_USB_TYPE:
+		val->intval = POWER_SUPPLY_USB_TYPE_DCP;
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+
+}
+
+static irqreturn_t rk817_plug_in_isr(int irq, void *cg)
+{
+	struct rk817_charger *charger;
+
+	charger = (struct rk817_charger *)cg;
+	charger->plugged_in = 1;
+	power_supply_changed(charger->chg_ps);
+	power_supply_changed(charger->bat_ps);
+	/* try to recalibrate capacity if we hit full charge. */
+	charger->soc_cal = 0;
+
+	rk817_read_props(charger);
+
+	dev_dbg(charger->dev, "Power Cord Inserted\n");
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t rk817_plug_out_isr(int irq, void *cg)
+{
+	struct rk817_charger *charger;
+	struct rk808 *rk808;
+
+	charger = (struct rk817_charger *)cg;
+	rk808 = charger->rk808;
+	charger->plugged_in = 0;
+	power_supply_changed(charger->bat_ps);
+	power_supply_changed(charger->chg_ps);
+
+	/* For some reason the bits of RK817_PMIC_CHRG_IN reset whenever the
+	 * power cord is unplugged. This was not documented in the BSP kernel
+	 * or the datasheet and only discovered by trial and error. Set minimum
+	 * USB input voltage to 4.5v and enable USB voltage input limit.
+	 */
+	regmap_write_bits(rk808->regmap, RK817_PMIC_CHRG_IN,
+			  RK817_USB_VLIM_SEL, (0x05 << 4));
+	regmap_write_bits(rk808->regmap, RK817_PMIC_CHRG_IN, RK817_USB_VLIM_EN,
+			  (0x01 << 7));
+
+	/* Set average USB input current limit to 1.5A and enable USB current
+	 * input limit.
+	 */
+	regmap_write_bits(rk808->regmap, RK817_PMIC_CHRG_IN,
+			  RK817_USB_ILIM_SEL, 0x03);
+	regmap_write_bits(rk808->regmap, RK817_PMIC_CHRG_IN, RK817_USB_ILIM_EN,
+			  (0x01 << 3));
+
+	rk817_read_props(charger);
+
+	dev_dbg(charger->dev, "Power Cord Removed\n");
+
+	return IRQ_HANDLED;
+}
+
+static enum power_supply_property rk817_bat_props[] = {
+	POWER_SUPPLY_PROP_PRESENT,
+	POWER_SUPPLY_PROP_STATUS,
+	POWER_SUPPLY_PROP_CHARGE_TYPE,
+	POWER_SUPPLY_PROP_CHARGE_FULL,
+	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
+	POWER_SUPPLY_PROP_CHARGE_EMPTY_DESIGN,
+	POWER_SUPPLY_PROP_CHARGE_NOW,
+	POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX,
+	POWER_SUPPLY_PROP_VOLTAGE_AVG,
+	POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX,
+	POWER_SUPPLY_PROP_CURRENT_AVG,
+	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
+	POWER_SUPPLY_PROP_CAPACITY,
+	POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
+};
+
+static enum power_supply_property rk817_chg_props[] = {
+	POWER_SUPPLY_PROP_ONLINE,
+	POWER_SUPPLY_PROP_USB_TYPE,
+	POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
+	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
+	POWER_SUPPLY_PROP_VOLTAGE_AVG,
+};
+
+static enum power_supply_usb_type rk817_usb_type[] = {
+	POWER_SUPPLY_USB_TYPE_DCP,
+	POWER_SUPPLY_USB_TYPE_UNKNOWN,
+};
+
+static const struct power_supply_desc rk817_bat_desc = {
+	.name = "rk817-battery",
+	.type = POWER_SUPPLY_TYPE_BATTERY,
+	.properties = rk817_bat_props,
+	.num_properties = ARRAY_SIZE(rk817_bat_props),
+	.get_property = rk817_bat_get_prop,
+};
+
+static const struct power_supply_desc rk817_chg_desc = {
+	.name = "rk817-charger",
+	.type = POWER_SUPPLY_TYPE_USB,
+	.usb_types = rk817_usb_type,
+	.num_usb_types = ARRAY_SIZE(rk817_usb_type),
+	.properties = rk817_chg_props,
+	.num_properties = ARRAY_SIZE(rk817_chg_props),
+	.get_property = rk817_chg_get_prop,
+};
+
+static int rk817_read_battery_nvram_values(struct rk817_charger *charger)
+{
+	u8 bulk_reg[3];
+	int ret;
+
+	/* Read the nvram data for full charge capacity. */
+	ret = regmap_bulk_read(charger->rk808->regmap,
+			       RK817_GAS_GAUGE_DATA3, bulk_reg, 3);
+	if (ret < 0)
+		return ret;
+	charger->fcc_mah = get_unaligned_le24(bulk_reg);
+
+	/* Sanity checking for values equal to zero or less than would be
+	 * practical for this device (BSP Kernel assumes 500mAH or less) for
+	 * practicality purposes.
+	 */
+	if (charger->fcc_mah < 500) {
+		dev_info(charger->dev,
+			 "Invalid NVRAM max charge, setting to %u uAH\n",
+			 charger->bat_charge_full_design_uah);
+		charger->fcc_mah = charger->bat_charge_full_design_uah / 1000;
+	}
+
+	/* Read the nvram for state of charge. */
+	ret = regmap_bulk_read(charger->rk808->regmap,
+			       RK817_GAS_GAUGE_BAT_R1, bulk_reg, 3);
+	if (ret < 0)
+		return ret;
+	charger->soc = get_unaligned_le24(bulk_reg);
+
+	return 0;
+}
+
+static int
+rk817_read_or_set_full_charge_on_boot(struct rk817_charger *charger,
+				struct power_supply_battery_info *bat_info)
+{
+	struct rk808 *rk808 = charger->rk808;
+	u8 bulk_reg[4];
+	u32 boot_voltage, boot_charge_mah, tmp;
+	int ret, reg, off_time;
+	int soc_tmp1, soc_tmp2, soc_tmp3;
+	bool first_boot;
+
+	/* Check if the battery is uninitalized. If it is, the columb counter
+	 * needs to be set up.
+	 */
+	ret = regmap_read(rk808->regmap, RK817_GAS_GAUGE_GG_STS, &reg);
+	if (ret < 0)
+		return ret;
+	first_boot = reg & RK817_BAT_CON;
+	/* If the battery is uninitialized, use the poweron voltage and an ocv
+	 * lookup to guess our charge. The number won't be very accurate until
+	 * we hit either our minimum voltage (0%) or full charge (100%).
+	 */
+	if (first_boot) {
+		regmap_bulk_read(rk808->regmap, RK817_GAS_GAUGE_PWRON_VOL_H,
+				 bulk_reg, 2);
+		tmp = get_unaligned_be16(bulk_reg);
+		boot_voltage = (charger->voltage_k * tmp) +
+				1000 * charger->voltage_b;
+		/* Since only implementation has no working thermistor, assume
+		 * 20C for OCV lookup. If lookup fails, report error with OCV
+		 * table.
+		 */
+		charger->soc = power_supply_batinfo_ocv2cap(bat_info,
+							    boot_voltage,
+							    20) * 1000;
+		if (charger->soc < 0)
+			charger->soc = 0;
+
+		/* Guess that full charge capacity is the design capacity */
+		charger->fcc_mah = charger->bat_charge_full_design_uah / 1000;
+		/* Set battery as "set up". BSP driver uses this value even
+		 * though datasheet claims it's a read-only value.
+		 */
+		regmap_write_bits(rk808->regmap, RK817_GAS_GAUGE_GG_STS,
+				  RK817_BAT_CON, 0);
+		/* Save nvram values */
+		ret = rk817_record_battery_nvram_values(charger);
+		if (ret < 0)
+			return ret;
+	} else {
+		ret = rk817_read_battery_nvram_values(charger);
+		if (ret < 0)
+			return ret;
+
+		regmap_bulk_read(rk808->regmap, RK817_GAS_GAUGE_Q_PRES_H3,
+				 bulk_reg, 4);
+		tmp = get_unaligned_be32(bulk_reg);
+		if (tmp < 0)
+			tmp = 0;
+		boot_charge_mah = ADC_TO_CHARGE_UAH(tmp,
+						    charger->res_div) / 1000;
+		/* Check if the columb counter has been off for more than 300
+		 * minutes as it tends to drift downward. If so, re-init soc
+		 * with the boot voltage instead. Note the unit values for the
+		 * OFF_CNT register appear to be in decaminutes and stops
+		 * counting at 2550 (0xFF) minutes. BSP kernel used OCV, but
+		 * for me occasionally that would show invalid values. Boot
+		 * voltage is only accurate for me on first poweron (not
+		 * reboots), but we shouldn't ever encounter an OFF_CNT more
+		 * than 0 on a reboot anyway.
+		 */
+		regmap_read(rk808->regmap, RK817_GAS_GAUGE_OFF_CNT, &off_time);
+		if (off_time >= 30) {
+			regmap_bulk_read(rk808->regmap,
+					 RK817_GAS_GAUGE_PWRON_VOL_H,
+					 bulk_reg, 2);
+			tmp = get_unaligned_be16(bulk_reg);
+			boot_voltage = (charger->voltage_k * tmp) +
+					1000 * charger->voltage_b;
+			charger->soc =
+				power_supply_batinfo_ocv2cap(bat_info,
+							     boot_voltage,
+							     20) * 1000;
+		} else {
+			charger->soc = (boot_charge_mah * 1000 * 100 /
+					charger->fcc_mah);
+		}
+	}
+
+	regmap_bulk_read(rk808->regmap, RK817_GAS_GAUGE_PWRON_VOL_H,
+			 bulk_reg, 2);
+	tmp = get_unaligned_be16(bulk_reg);
+	boot_voltage = (charger->voltage_k * tmp) + 1000 * charger->voltage_b;
+	soc_tmp1 = power_supply_batinfo_ocv2cap(bat_info,
+						boot_voltage, 20) * 1000;
+	regmap_bulk_read(rk808->regmap, RK817_GAS_GAUGE_Q_PRES_H3,
+			 bulk_reg, 4);
+	tmp = get_unaligned_be32(bulk_reg);
+	if (tmp < 0)
+		tmp = 0;
+	boot_charge_mah = ADC_TO_CHARGE_UAH(tmp, charger->res_div) / 1000;
+	soc_tmp2 = (boot_charge_mah * 1000 * 100 / charger->fcc_mah);
+	regmap_bulk_read(rk808->regmap, RK817_GAS_GAUGE_OCV_VOL_H,
+			 bulk_reg, 2);
+	tmp = get_unaligned_be16(bulk_reg);
+	boot_voltage = (charger->voltage_k * tmp) + 1000 * charger->voltage_b;
+	soc_tmp3 = power_supply_batinfo_ocv2cap(bat_info,
+						boot_voltage, 20) * 1000;
+
+	/* Now we have our full charge capacity and soc, init the columb
+	 * counter.
+	 */
+	boot_charge_mah = charger->soc * charger->fcc_mah / 100 / 1000;
+	if (boot_charge_mah > charger->fcc_mah)
+		boot_charge_mah = charger->fcc_mah;
+	tmp = CHARGE_TO_ADC(boot_charge_mah, charger->res_div);
+	put_unaligned_be32(tmp, bulk_reg);
+	ret = regmap_bulk_write(rk808->regmap, RK817_GAS_GAUGE_Q_INIT_H3,
+			  bulk_reg, 4);
+	if (ret < 0)
+		return ret;
+
+	/* Set QMAX value to max design capacity. */
+	tmp = CHARGE_TO_ADC((charger->bat_charge_full_design_uah / 1000),
+			    charger->res_div);
+	put_unaligned_be32(tmp, bulk_reg);
+	ret = regmap_bulk_write(rk808->regmap, RK817_GAS_GAUGE_Q_MAX_H3,
+				bulk_reg, 4);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static int rk817_battery_init(struct rk817_charger *charger,
+			      struct power_supply_battery_info *bat_info)
+{
+	struct rk808 *rk808 = charger->rk808;
+	u32 tmp, max_chg_vol_mv, max_chg_cur_ma;
+	u8 max_chg_vol_reg, chg_term_i_reg, max_chg_cur_reg;
+	int ret, chg_term_ma;
+	u8 bulk_reg[2];
+
+	/* Get initial plug state */
+	regmap_read(rk808->regmap, RK817_SYS_STS, &tmp);
+	charger->plugged_in = (tmp & RK817_PLUG_IN_STS);
+
+	/* Turn on all ADC functions to measure battery, USB, and sys voltage,
+	 * as well as batt temp. Note only tested implementation so far does
+	 * not use a battery with a thermistor.
+	 */
+	regmap_write(rk808->regmap, RK817_GAS_GAUGE_ADC_CONFIG0, 0xfc);
+
+	/* Set relax mode voltage sampling interval and ADC offset calibration
+	 * interval to 8 minutes to mirror BSP kernel. Set voltage and current
+	 * modes to average to mirror BSP kernel.
+	 */
+	regmap_write(rk808->regmap, RK817_GAS_GAUGE_GG_CON, 0x04);
+
+	/* Calibrate voltage like the BSP does here. */
+	rk817_bat_calib_vol(charger);
+
+	/* Write relax threshold, derived from sleep enter current. */
+	tmp = CURRENT_TO_ADC(charger->sleep_enter_current_ua,
+			     charger->res_div);
+	put_unaligned_be16(tmp, bulk_reg);
+	regmap_bulk_write(rk808->regmap, RK817_GAS_GAUGE_RELAX_THRE_H,
+			  bulk_reg, 2);
+
+	/* Write sleep sample current, derived from sleep filter current. */
+	tmp = CURRENT_TO_ADC(charger->sleep_filter_current_ua,
+			     charger->res_div);
+	put_unaligned_be16(tmp, bulk_reg);
+	regmap_bulk_write(rk808->regmap, RK817_GAS_GAUGE_SLEEP_CON_SAMP_CUR_H,
+			  bulk_reg, 2);
+
+	/* Restart battery relax voltage */
+	regmap_write_bits(rk808->regmap, RK817_GAS_GAUGE_GG_STS,
+			  RK817_RELAX_VOL_UPD, (0x0 << 2));
+
+	/* Set OCV Threshold Voltage to 127.5mV. This was hard coded like this
+	 * in the BSP.
+	 */
+	regmap_write(rk808->regmap, RK817_GAS_GAUGE_OCV_THRE_VOL, 0xff);
+
+	/* Set maximum charging voltage to battery max voltage. Trying to be
+	 * incredibly safe with these value, as setting them wrong could
+	 * overcharge the battery, which would be very bad.
+	 */
+	max_chg_vol_mv = bat_info->constant_charge_voltage_max_uv / 1000;
+	max_chg_cur_ma = bat_info->constant_charge_current_max_ua / 1000;
+
+	if (max_chg_vol_mv < 4100) {
+		return dev_err_probe(charger->dev, -EINVAL,
+		       "invalid max charger voltage, value %u unsupported\n",
+			max_chg_vol_mv * 1000);
+	}
+	if (max_chg_vol_mv > 4450) {
+		dev_info(charger->dev,
+			 "Setting max charge voltage to 4450000uv\n");
+		max_chg_vol_mv = 4450;
+	}
+
+	if (max_chg_cur_ma < 500) {
+		return dev_err_probe(charger->dev, -EINVAL,
+		       "invalid max charger current, value %u unsupported\n",
+		       max_chg_cur_ma * 1000);
+	}
+	if (max_chg_cur_ma > 3500)
+		dev_info(charger->dev,
+			 "Setting max charge current to 3500000ua\n");
+
+	/* Now that the values are sanity checked, if we subtract 4100 from the
+	 * max voltage and divide by 50, we conviently get the exact value for
+	 * the registers, which are 4.1v, 4.15v, 4.2v, 4.25v, 4.3v, 4.35v,
+	 * 4.4v, and 4.45v; these correspond to values 0x00 through 0x07.
+	 */
+	max_chg_vol_reg = (max_chg_vol_mv - 4100) / 50;
+
+	max_chg_cur_reg = rk817_chg_cur_to_reg(max_chg_cur_ma);
+
+	if (max_chg_vol_reg < 0 || max_chg_vol_reg > 7) {
+		return dev_err_probe(charger->dev, -EINVAL,
+		       "invalid max charger voltage, value %u unsupported\n",
+		       max_chg_vol_mv * 1000);
+	}
+	if (max_chg_cur_reg < 0 || max_chg_cur_reg > 7) {
+		return dev_err_probe(charger->dev, -EINVAL,
+		       "invalid max charger current, value %u unsupported\n",
+		       max_chg_cur_ma * 1000);
+	}
+
+	/* Write the values to the registers, and deliver an emergency warning
+	 * in the event they are not written correctly.
+	 */
+	ret = regmap_write_bits(rk808->regmap, RK817_PMIC_CHRG_OUT,
+				RK817_CHRG_VOL_SEL, (max_chg_vol_reg << 4));
+	if (ret) {
+		dev_emerg(charger->dev,
+			  "Danger, unable to set max charger voltage: %u\n",
+			  ret);
+	}
+
+	ret = regmap_write_bits(rk808->regmap, RK817_PMIC_CHRG_OUT,
+				RK817_CHRG_CUR_SEL, max_chg_cur_reg);
+	if (ret) {
+		dev_emerg(charger->dev,
+			  "Danger, unable to set max charger current: %u\n",
+			  ret);
+	}
+
+	/* Set charge finishing mode to analog */
+	regmap_write_bits(rk808->regmap, RK817_PMIC_CHRG_TERM,
+			  RK817_CHRG_TERM_ANA_DIG, (0x0 << 2));
+
+	/* Set charge finish current, warn if value not in range and keep
+	 * default.
+	 */
+	chg_term_ma = bat_info->charge_term_current_ua / 1000;
+	if (chg_term_ma < 150 || chg_term_ma > 400) {
+		dev_warn(charger->dev,
+			 "Invalid charge termination %u, keeping default\n",
+			 chg_term_ma * 1000);
+		chg_term_ma = 200;
+	}
+
+	/* Values of 150ma, 200ma, 300ma, and 400ma correspond to 00, 01, 10,
+	 * and 11.
+	 */
+	chg_term_i_reg = (chg_term_ma - 100) / 100;
+	regmap_write_bits(rk808->regmap, RK817_PMIC_CHRG_TERM,
+			  RK817_CHRG_TERM_ANA_SEL, chg_term_i_reg);
+
+	ret = rk817_read_or_set_full_charge_on_boot(charger, bat_info);
+	if (ret < 0)
+		return ret;
+
+	/* Set minimum USB input voltage to 4.5v and enable USB voltage input
+	 * limit.
+	 */
+	regmap_write_bits(rk808->regmap, RK817_PMIC_CHRG_IN,
+			  RK817_USB_VLIM_SEL, (0x05 << 4));
+	regmap_write_bits(rk808->regmap, RK817_PMIC_CHRG_IN, RK817_USB_VLIM_EN,
+			  (0x01 << 7));
+
+	/* Set average USB input current limit to 1.5A and enable USB current
+	 * input limit.
+	 */
+	regmap_write_bits(rk808->regmap, RK817_PMIC_CHRG_IN,
+			  RK817_USB_ILIM_SEL, 0x03);
+	regmap_write_bits(rk808->regmap, RK817_PMIC_CHRG_IN, RK817_USB_ILIM_EN,
+			  (0x01 << 3));
+
+	return 0;
+}
+
+static void rk817_charging_monitor(struct work_struct *work)
+{
+	struct rk817_charger *charger;
+
+	charger = container_of(work, struct rk817_charger, work.work);
+
+	rk817_read_props(charger);
+
+	/* Run every 8 seconds like the BSP driver did. */
+	schedule_delayed_work(&charger->work, msecs_to_jiffies(8000));
+}
+
+static int rk817_charger_probe(struct platform_device *pdev)
+{
+	struct rk808 *rk808 = dev_get_drvdata(pdev->dev.parent);
+	struct rk817_charger *charger;
+	struct device_node *node;
+	struct power_supply_battery_info *bat_info;
+	struct device *dev = &pdev->dev;
+	struct power_supply_config pscfg = {};
+	int plugin_irq, plugout_irq;
+	int of_value;
+	int ret;
+
+	node = of_get_child_by_name(dev->parent->of_node, "charger");
+	if (!node)
+		return -ENODEV;
+
+	charger = devm_kzalloc(&pdev->dev, sizeof(*charger), GFP_KERNEL);
+	if (!charger)
+		return -ENOMEM;
+
+	charger->rk808 = rk808;
+
+	charger->dev = &pdev->dev;
+	platform_set_drvdata(pdev, charger);
+
+	rk817_bat_calib_vol(charger);
+
+	pscfg.drv_data = charger;
+	pscfg.of_node = node;
+
+	/* Get sample resistor value. Note only values of 10000 or 20000
+	 * microohms are allowed. Schematic for my test implementation (an
+	 * Odroid Go Advance) shows a 10 milliohm resistor for reference.
+	 */
+	ret = of_property_read_u32(node, "rockchip,resistor-sense-micro-ohms",
+				   &of_value);
+	if (ret < 0) {
+		return dev_err_probe(dev, ret,
+				     "Error reading sample resistor value\n");
+	}
+	/* Store as a 1 or a 2, since all we really use the value for is as a
+	 * divisor in some calculations.
+	 */
+	charger->res_div = (of_value == 20000) ? 2 : 1;
+
+	/* Get sleep enter current value. Not sure what this value is for
+	 * other than to help calibrate the relax threshold.
+	 */
+	ret = of_property_read_u32(node,
+				   "rockchip,sleep-enter-current-microamp",
+				   &of_value);
+	if (ret < 0) {
+		return dev_err_probe(dev, ret,
+				     "Error reading sleep enter cur value\n");
+	}
+	charger->sleep_enter_current_ua = of_value;
+
+	/* Get sleep filter current value */
+	ret = of_property_read_u32(node,
+				   "rockchip,sleep-filter-current-microamp",
+				   &of_value);
+	if (ret < 0) {
+		return dev_err_probe(dev, ret,
+				     "Error reading sleep filter cur value\n");
+	}
+
+	charger->sleep_filter_current_ua = of_value;
+
+	charger->bat_ps = devm_power_supply_register(&pdev->dev,
+						     &rk817_bat_desc, &pscfg);
+
+	charger->chg_ps = devm_power_supply_register(&pdev->dev,
+						     &rk817_chg_desc, &pscfg);
+
+	if (IS_ERR(charger->chg_ps))
+		return dev_err_probe(dev, -EINVAL,
+				     "Battery failed to probe\n");
+
+	if (IS_ERR(charger->chg_ps))
+		return dev_err_probe(dev, -EINVAL,
+				     "Charger failed to probe\n");
+
+	ret = power_supply_get_battery_info(charger->bat_ps,
+					    &bat_info);
+	if (ret) {
+		return dev_err_probe(dev, ret,
+				     "Unable to get battery info: %d\n", ret);
+	}
+
+	if ((!bat_info->charge_full_design_uah) ||
+	    (!bat_info->voltage_min_design_uv) ||
+	    (!bat_info->voltage_max_design_uv) ||
+	    (!bat_info->constant_charge_voltage_max_uv) ||
+	    (!bat_info->constant_charge_current_max_ua) ||
+	    (!bat_info->charge_term_current_ua)) {
+		return dev_err_probe(dev, -EINVAL,
+				     "Required battery info missing.\n");
+	}
+
+	charger->bat_charge_full_design_uah = bat_info->charge_full_design_uah;
+	charger->bat_voltage_min_design_uv = bat_info->voltage_min_design_uv;
+	charger->bat_voltage_max_design_uv = bat_info->voltage_max_design_uv;
+
+	/* Has to run after power_supply_get_battery_info as it depends on some
+	 * values discovered from that routine.
+	 */
+	ret = rk817_battery_init(charger, bat_info);
+	if (ret)
+		return ret;
+
+	power_supply_put_battery_info(charger->bat_ps, bat_info);
+
+	plugin_irq = platform_get_irq(pdev, 0);
+	if (plugin_irq < 0)
+		return plugin_irq;
+
+	plugout_irq = platform_get_irq(pdev, 1);
+	if (plugout_irq < 0)
+		return plugout_irq;
+
+	ret = devm_request_threaded_irq(charger->dev, plugin_irq, NULL,
+					rk817_plug_in_isr,
+					IRQF_TRIGGER_RISING | IRQF_ONESHOT,
+					"rk817_plug_in", charger);
+	if (ret) {
+		return dev_err_probe(&pdev->dev, ret,
+				      "plug_in_irq request failed!\n");
+	}
+
+	ret = devm_request_threaded_irq(charger->dev, plugout_irq, NULL,
+					rk817_plug_out_isr,
+					IRQF_TRIGGER_RISING | IRQF_ONESHOT,
+					"rk817_plug_out", charger);
+	if (ret) {
+		return dev_err_probe(&pdev->dev, ret,
+				     "plug_out_irq request failed!\n");
+	}
+
+	INIT_DELAYED_WORK(&charger->work, rk817_charging_monitor);
+	/* Get and populate the first set of values. */
+	schedule_delayed_work(&charger->work, 0);
+
+	return 0;
+}
+
+
+static struct platform_driver rk817_charger_driver = {
+	.probe    = rk817_charger_probe,
+	.driver   = {
+		.name  = "rk817-charger",
+	},
+};
+module_platform_driver(rk817_charger_driver);
+
+MODULE_DESCRIPTION("Battery power supply driver for RK817 PMIC");
+MODULE_AUTHOR("Maya Matuszczyk <maccraft123mc@gmail.com>");
+MODULE_LICENSE("GPL");