path: root/drivers/power/supply/bd99954-charger.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * ROHM BD99954 charger driver
 *
 * Copyright (C) 2020 Rohm Semiconductors
 *	Originally written by:
 *		Mikko Mutanen <mikko.mutanen@fi.rohmeurope.com>
 *		Markus Laine <markus.laine@fi.rohmeurope.com>
 *	Bugs added by:
 *		Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
 */

/*
 *   The battery charging profile of BD99954.
 *
 *   Curve (1) represents charging current.
 *   Curve (2) represents battery voltage.
 *
 *   The BD99954 data sheet divides charging to three phases.
 *   a) Trickle-charge with constant current (8).
 *   b) pre-charge with constant current (6)
 *   c) fast-charge, first with constant current (5) phase. After
 *      the battery voltage has reached target level (4) we have constant
 *      voltage phase until charging current has dropped to termination
 *      level (7)
 *
 *    V ^                                                        ^ I
 *      .                                                        .
 *      .                                                        .
 *(4)` `.` ` ` ` ` ` ` ` ` ` ` ` ` ` ----------------------------.
 *      .                           :/                           .
 *      .                     o----+/:/ ` ` ` ` ` ` ` ` ` ` ` ` `.` ` (5)
 *      .                     +   ::  +                          .
 *      .                     +  /-   --                         .
 *      .                     +`/-     +                         .
 *      .                     o/-      -:                        .
 *      .                    .s.        +`                       .
 *      .                  .--+         `/                       .
 *      .               ..``  +          .:                      .
 *      .             -`      +           --                     .
 *      .    (2)  ...``       +            :-                    .
 *      .    ...``            +             -:                   .
 *(3)` `.`.""  ` ` ` `+-------- ` ` ` ` ` ` `.:` ` ` ` ` ` ` ` ` .` ` (6)
 *      .             +                       `:.                .
 *      .             +                         -:               .
 *      .             +                           -:.            .
 *      .             +                             .--.         .
 *      .   (1)       +                                `.+` ` ` `.` ` (7)
 *      -..............` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` + ` ` ` .` ` (8)
 *      .                                                +       -
 *      -------------------------------------------------+++++++++-->
 *      |   trickle   |  pre  |          fast            |
 *
 * Details of DT properties for different limits can be found from BD99954
 * device tree binding documentation.
 */

#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/interrupt.h>
#include <linux/i2c.h>
#include <linux/kernel.h>
#include <linux/linear_range.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/power_supply.h>
#include <linux/property.h>
#include <linux/regmap.h>
#include <linux/types.h>

#include "bd99954-charger.h"

struct battery_data {
	u16 precharge_current;	/* Trickle-charge Current */
	u16 fc_reg_voltage;	/* Fast Charging Regulation Voltage */
	u16 voltage_min;
	u16 voltage_max;
};

/* Initial field values, converted to initial register values */
struct bd9995x_init_data {
	u16 vsysreg_set;	/* VSYS Regulation Setting */
	u16 ibus_lim_set;	/* VBUS input current limitation */
	u16 icc_lim_set;	/* VCC/VACP Input Current Limit Setting */
	u16 itrich_set;		/* Trickle-charge Current Setting */
	u16 iprech_set;		/* Pre-Charge Current Setting */
	u16 ichg_set;		/* Fast-Charge constant current */
	u16 vfastchg_reg_set1;	/* Fast Charging Regulation Voltage */
	u16 vprechg_th_set;	/* Pre-charge Voltage Threshold Setting */
	u16 vrechg_set;		/* Re-charge Battery Voltage Setting */
	u16 vbatovp_set;	/* Battery Over Voltage Threshold Setting */
	u16 iterm_set;		/* Charging termination current */
};

struct bd9995x_state {
	u8 online;
	u16 chgstm_status;
	u16 vbat_vsys_status;
	u16 vbus_vcc_status;
};

struct bd9995x_device {
	struct i2c_client *client;
	struct device *dev;
	struct power_supply *charger;

	struct regmap *rmap;
	struct regmap_field *rmap_fields[F_MAX_FIELDS];

	int chip_id;
	int chip_rev;
	struct bd9995x_init_data init_data;
	struct bd9995x_state state;

	struct mutex lock; /* Protect state data */
};

static const struct regmap_range bd9995x_readonly_reg_ranges[] = {
	regmap_reg_range(CHGSTM_STATUS, SEL_ILIM_VAL),
	regmap_reg_range(IOUT_DACIN_VAL, IOUT_DACIN_VAL),
	regmap_reg_range(VCC_UCD_STATUS, VCC_IDD_STATUS),
	regmap_reg_range(VBUS_UCD_STATUS, VBUS_IDD_STATUS),
	regmap_reg_range(CHIP_ID, CHIP_REV),
	regmap_reg_range(SYSTEM_STATUS, SYSTEM_STATUS),
	regmap_reg_range(IBATP_VAL, VBAT_AVE_VAL),
	regmap_reg_range(VTH_VAL, EXTIADP_AVE_VAL),
};

static const struct regmap_access_table bd9995x_writeable_regs = {
	.no_ranges = bd9995x_readonly_reg_ranges,
	.n_no_ranges = ARRAY_SIZE(bd9995x_readonly_reg_ranges),
};

static const struct regmap_range bd9995x_volatile_reg_ranges[] = {
	regmap_reg_range(CHGSTM_STATUS, WDT_STATUS),
	regmap_reg_range(VCC_UCD_STATUS, VCC_IDD_STATUS),
	regmap_reg_range(VBUS_UCD_STATUS, VBUS_IDD_STATUS),
	regmap_reg_range(INT0_STATUS, INT7_STATUS),
	regmap_reg_range(SYSTEM_STATUS, SYSTEM_CTRL_SET),
	regmap_reg_range(IBATP_VAL, EXTIADP_AVE_VAL), /* Measurement regs */
};

static const struct regmap_access_table bd9995x_volatile_regs = {
	.yes_ranges = bd9995x_volatile_reg_ranges,
	.n_yes_ranges = ARRAY_SIZE(bd9995x_volatile_reg_ranges),
};

static const struct regmap_range_cfg regmap_range_cfg[] = {
	{
	.selector_reg     = MAP_SET,
	.selector_mask    = 0xFFFF,
	.selector_shift   = 0,
	.window_start     = 0,
	.window_len       = 0x100,
	.range_min        = 0 * 0x100,
	.range_max        = 3 * 0x100,
	},
};

static const struct regmap_config bd9995x_regmap_config = {
	.reg_bits = 8,
	.val_bits = 16,
	.reg_stride = 1,

	.max_register = 3 * 0x100,
	.cache_type = REGCACHE_RBTREE,

	.ranges = regmap_range_cfg,
	.num_ranges = ARRAY_SIZE(regmap_range_cfg),
	.val_format_endian = REGMAP_ENDIAN_LITTLE,
	.wr_table = &bd9995x_writeable_regs,
	.volatile_table = &bd9995x_volatile_regs,
};

enum bd9995x_chrg_fault {
	CHRG_FAULT_NORMAL,
	CHRG_FAULT_INPUT,
	CHRG_FAULT_THERMAL_SHUTDOWN,
	CHRG_FAULT_TIMER_EXPIRED,
};

static int bd9995x_get_prop_batt_health(struct bd9995x_device *bd)
{
	int ret, tmp;

	ret = regmap_field_read(bd->rmap_fields[F_BATTEMP], &tmp);
	if (ret)
		return POWER_SUPPLY_HEALTH_UNKNOWN;

	/* TODO: Check these against datasheet page 34 */