Re: [RFC PATCH 2/2] Add Dialog DA9030 battery charger driver

From: Anton Vorontsov
Date: Thu Dec 18 2008 - 15:56:04 EST

Hi all,

On Thu, Dec 18, 2008 at 01:36:28PM +0200, Mike Rapoport wrote:
[...]
> > 2 remarks though:
> > 1) I'd like to get Anton Ack on it.

Samuel, as it depends on the MFD part, feel free to merge it into your
tree.

Acked-by: Anton Vorontsov <cbouatmailru@xxxxxxxxx>

> > 2) This patch wont build, as the Makefile is trying to build da903x_battery.o
> > while da9030_battery.c is created. I guess it'd make sense to rename it
> > da903x_battery.c.
>
> Last minute changes...
> I actually prefer to keep it da9030 for now because I have no idea how much
> DA9034 charger differs from DA9030.
> So, here's the updated patch that fixes Kconfig and Makefile entries and
> addresses the points Andrew raised at [1]

Mike,

Thanks for the patch, looks really good. Few comments down below.

[...]
> +++ b/drivers/power/da9030_battery.c
> @@ -0,0 +1,593 @@
> +/*
> + * Battery charger driver for Dialog Semiconductor DA9030
> + *
> + * Copyright (C) 2008 Compulab, Ltd.
> + * Mike Rapoport <mike@xxxxxxxxxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +

The code should explicitly include all the needed headers.

#include <linux/kernel.h> (for container_of, sprintf, ...)
#include <linux/init.h> (initcalls)
#include <linux/types.h> (uint8_t)
#include <linux/device.h> (struct device)
#include <linux/workqueue.h> (delayedwork)

^^^ This is the only real comment. All the rest are nitpicks,
which you can freely ignore if you like.

> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/power_supply.h>
> +#include <linux/mfd/da903x.h>
> +
> +#include <linux/debugfs.h>
> +#include <linux/seq_file.h>
> +
> +#define DA9030_STATUS_CHDET (1 << 3)
> +
> +#define DA9030_FAULT_LOG 0x0a
> +#define DA9030_FAULT_LOG_OVER_TEMP (1 << 7)
> +#define DA9030_FAULT_LOG_VBAT_OVER (1 << 4)
> +
> +#define DA9030_CHARGE_CONTROL 0x28
> +#define DA9030_CHRG_CHARGER_ENABLE (1 << 7)
> +
> +#define DA9030_ADC_MAN_CONTROL 0x30
> +#define DA9030_ADC_TBATREF_ENABLE (1 << 5)
> +#define DA9030_ADC_LDO_INT_ENABLE (1 << 4)
> +
> +#define DA9030_ADC_AUTO_CONTROL 0x31
> +#define DA9030_ADC_TBAT_ENABLE (1 << 5)
> +#define DA9030_ADC_VBAT_IN_TXON (1 << 4)
> +#define DA9030_ADC_VCH_ENABLE (1 << 3)
> +#define DA9030_ADC_ICH_ENABLE (1 << 2)
> +#define DA9030_ADC_VBAT_ENABLE (1 << 1)
> +#define DA9030_ADC_AUTO_SLEEP_ENABLE (1 << 0)
> +
> +#define DA9030_VBATMON 0x32
> +#define DA9030_VBATMONTXON 0x33
> +#define DA9030_TBATHIGHP 0x34
> +#define DA9030_TBATHIGHN 0x35
> +#define DA9030_TBATLOW 0x36
> +
> +#define DA9030_VBAT_RES 0x41
> +#define DA9030_VBATMIN_RES 0x42
> +#define DA9030_VBATMINTXON_RES 0x43
> +#define DA9030_ICHMAX_RES 0x44
> +#define DA9030_ICHMIN_RES 0x45
> +#define DA9030_ICHAVERAGE_RES 0x46
> +#define DA9030_VCHMAX_RES 0x47
> +#define DA9030_VCHMIN_RES 0x48
> +#define DA9030_TBAT_RES 0x49
> +
> +struct da9030_adc_res {
> + uint8_t vbat_res;
> + uint8_t vbatmin_res;
> + uint8_t vbatmintxon;
> + uint8_t ichmax_res;
> + uint8_t ichmin_res;
> + uint8_t ichaverage_res;
> + uint8_t vchmax_res;
> + uint8_t vchmin_res;
> + uint8_t tbat_res;
> + uint8_t adc_in4_res;
> + uint8_t adc_in5_res;
> +};
> +
> +struct da9030_battery_thresholds {
> + int tbat_low;
> + int tbat_high;
> + int tbat_restart;
> +
> + int vbat_low;
> + int vbat_crit;
> + int vbat_charge_start;
> + int vbat_charge_stop;
> + int vbat_charge_restart;
> +
> + int vcharge_min;
> + int vcharge_max;
> +};
> +
> +struct da9030_charger {
> + struct power_supply psy;
> +
> + struct device *master;
> +
> + struct da9030_adc_res adc;
> + struct delayed_work work;
> + unsigned int interval;
> +
> + struct power_supply_info *battery_info;
> +
> + struct da9030_battery_thresholds thresholds;
> +
> + unsigned int charge_milliamp;
> + unsigned int charge_millivolt;
> +
> + /* charger status */
> + int chdet:1;

In kernel we can use bool type, and true/false constants.

> + uint8_t fault;
> + int mA;
> + int mV;
> + int is_on;
> +
> + struct notifier_block nb;
> +
> + /* platform callbacks for battery low and critical events */
> + void (*battery_low)(void);
> + void (*battery_critical)(void);
> +
> + struct dentry *debug_file;
> +};
> +
> +static inline int da9030_reg_to_mV(int reg)
> +{
> + return ((reg * 2650) >> 8) + 2650;
> +}
> +
> +static inline int da9030_millivolt_to_reg(int mV)
> +{
> + return ((mV - 2650) << 8) / 2650;
> +}
> +
> +static inline int da9030_reg_to_mA(int reg)
> +{
> + return ((reg * 24000) >> 8) / 15;
> +}
> +
> +#ifdef CONFIG_DEBUG_FS
> +

(1)

> +static int bat_debug_show(struct seq_file *s, void *data)
> +{
> + struct da9030_charger *charger = s->private;
> +
> + seq_printf(s, "charger is %s\n", charger->is_on ? "on" : "off");
> + if (charger->chdet) {
> + seq_printf(s, "iset = %dmA, vset = %dmV\n",
> + charger->mA, charger->mV);
> + }
> +
> + seq_printf(s, "vbat_res = %d (%dmV)\n",
> + charger->adc.vbat_res,
> + da9030_reg_to_mV(charger->adc.vbat_res));
> + seq_printf(s, "vbatmin_res = %d (%dmV)\n",
> + charger->adc.vbatmin_res,
> + da9030_reg_to_mV(charger->adc.vbatmin_res));
> + seq_printf(s, "vbatmintxon = %d (%dmV)\n",
> + charger->adc.vbatmintxon,
> + da9030_reg_to_mV(charger->adc.vbatmintxon));
> + seq_printf(s, "ichmax_res = %d (%dmA)\n",
> + charger->adc.ichmax_res,
> + da9030_reg_to_mV(charger->adc.ichmax_res));
> + seq_printf(s, "ichmin_res = %d (%dmA)\n",
> + charger->adc.ichmin_res,
> + da9030_reg_to_mA(charger->adc.ichmin_res));
> + seq_printf(s, "ichaverage_res = %d (%dmA)\n",
> + charger->adc.ichaverage_res,
> + da9030_reg_to_mA(charger->adc.ichaverage_res));
> + seq_printf(s, "vchmax_res = %d (%dmV)\n",
> + charger->adc.vchmax_res,
> + da9030_reg_to_mA(charger->adc.vchmax_res));
> + seq_printf(s, "vchmin_res = %d (%dmV)\n",
> + charger->adc.vchmin_res,
> + da9030_reg_to_mV(charger->adc.vchmin_res));
> +
> + return 0;
> +}
> +
> +static int debug_open(struct inode *inode, struct file *file)
> +{
> + return single_open(file, bat_debug_show, inode->i_private);
> +}
> +
> +static const struct file_operations bat_debug_fops = {
> + .open = debug_open,
> + .read = seq_read,
> + .llseek = seq_lseek,
> + .release = single_release,
> +};
> +
> +static struct dentry *da9030_bat_create_debugfs(struct da9030_charger *charger)
> +{
> + charger->debug_file = debugfs_create_file("charger", 0666, 0, charger,
> + &bat_debug_fops);
> + return charger->debug_file;
> +}
> +
> +static void da9030_bat_remove_debugfs(struct da9030_charger *charger)
> +{
> + debugfs_remove(charger->debug_file);
> +}

I'd put an empty line here, or remove empty line at (1). Just for
consistency.

> +#else
> +static inline struct dentry *da9030_bat_create_debugfs(struct da9030_charger *charger)
> +{
> + return NULL;
> +}
> +static inline void da9030_bat_remove_debugfs(struct da9030_charger *charger)
> +{
> +}
> +#endif
> +
> +static inline void da9030_read_adc(struct da9030_charger *charger,
> + struct da9030_adc_res *adc)
> +{
> + da903x_reads(charger->master, DA9030_VBAT_RES,
> + sizeof(*adc), (uint8_t *)adc);
> +}
> +
> +static void da9030_charger_update_state(struct da9030_charger *charger)
> +{
> + uint8_t val;
> +
> + da903x_read(charger->master, DA9030_CHARGE_CONTROL, &val);
> + charger->is_on = (val & DA9030_CHRG_CHARGER_ENABLE) ? 1 : 0;
> + charger->mA = ((val >> 3) & 0xf) * 100;
> + charger->mV = (val & 0x7) * 50 + 4000;
> +
> + da9030_read_adc(charger, &charger->adc);
> + da903x_read(charger->master, DA9030_FAULT_LOG, &charger->fault);
> + charger->chdet = da903x_query_status(charger->master,
> + DA9030_STATUS_CHDET);
> +}
> +
> +static void da9030_set_charge(struct da9030_charger *charger, int on)
> +{
> + uint8_t val = 0;

= 0 isn't necessary here.

> +
> + if (on) {
> + val = DA9030_CHRG_CHARGER_ENABLE;
> + val |= (charger->charge_milliamp / 100) << 3;
> + val |= (charger->charge_millivolt - 4000) / 50;
> + charger->is_on = 1;
> + } else {
> + val = 0;
> + charger->is_on = 0;
> + }
> +
> + da903x_write(charger->master, DA9030_CHARGE_CONTROL, val);
> +}
> +
> +static void da9030_charger_check_state(struct da9030_charger *charger)
> +{
> + da9030_charger_update_state(charger);
> +
> + /* we wake or boot with external power on */
> + if (!charger->is_on) {
> + if ((charger->chdet) &&
> + (charger->adc.vbat_res <
> + charger->thresholds.vbat_charge_start)) {
> + da9030_set_charge(charger, 1);
> + }
> + } else {
> + if (charger->adc.vbat_res >=
> + charger->thresholds.vbat_charge_stop) {
> + da9030_set_charge(charger, 0);
> + da903x_write(charger->master, DA9030_VBATMON,
> + charger->thresholds.vbat_charge_restart);
> + } else if (charger->adc.vbat_res >
> + charger->thresholds.vbat_low) {
> + /* we are charging and passed LOW_THRESH,
> + so upate DA9030 VBAT threshold
> + */
> + da903x_write(charger->master, DA9030_VBATMON,
> + charger->thresholds.vbat_low);
> + }
> + if (charger->adc.vchmax_res > charger->thresholds.vcharge_max ||
> + charger->adc.vchmin_res < charger->thresholds.vcharge_min ||
> + /* Tempreture readings are negative */
> + charger->adc.tbat_res < charger->thresholds.tbat_high ||
> + charger->adc.tbat_res > charger->thresholds.tbat_low) {
> + /* disable charger */
> + da9030_set_charge(charger, 0);
> + }
> + }
> +}
> +
> +static void da9030_charging_monitor(struct work_struct *work)
> +{
> + struct da9030_charger *charger;
> +
> + charger = container_of(work, struct da9030_charger, work.work);
> +
> + da9030_charger_check_state(charger);
> +
> + /* reschedule for the next time */
> + schedule_delayed_work(&charger->work, charger->interval);
> +}
> +
> +static enum power_supply_property da9030_battery_props[] = {
> + POWER_SUPPLY_PROP_MODEL_NAME,
> + POWER_SUPPLY_PROP_STATUS,
> + POWER_SUPPLY_PROP_HEALTH,
> + POWER_SUPPLY_PROP_TECHNOLOGY,
> + POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
> + POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
> + POWER_SUPPLY_PROP_VOLTAGE_NOW,
> + POWER_SUPPLY_PROP_CURRENT_AVG,
> +};
> +
> +static void da9030_battery_check_status(struct da9030_charger *charger,
> + union power_supply_propval *val)
> +{
> + if (charger->chdet) {
> + if (charger->is_on)
> + val->intval = POWER_SUPPLY_STATUS_CHARGING;
> + else
> + val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
> + } else {
> + val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
> + }
> +}
> +
> +static void da9030_battery_check_health(struct da9030_charger *charger,
> + union power_supply_propval *val)
> +{
> + if (charger->fault & DA9030_FAULT_LOG_OVER_TEMP)
> + val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
> + else if (charger->fault & DA9030_FAULT_LOG_VBAT_OVER)
> + val->intval = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
> + else
> + val->intval = POWER_SUPPLY_HEALTH_GOOD;
> +}
> +
> +static int da9030_battery_get_property(struct power_supply *psy,
> + enum power_supply_property psp,
> + union power_supply_propval *val)
> +{
> + struct da9030_charger *charger;
> + charger = container_of(psy, struct da9030_charger, psy);
> +
> + switch (psp) {
> + case POWER_SUPPLY_PROP_STATUS:
> + da9030_battery_check_status(charger, val);
> + break;
> + case POWER_SUPPLY_PROP_HEALTH:
> + da9030_battery_check_health(charger, val);
> + break;
> + case POWER_SUPPLY_PROP_TECHNOLOGY:
> + val->intval = charger->battery_info->technology;
> + break;
> + case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
> + val->intval = charger->battery_info->voltage_max_design;
> + break;
> + case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
> + val->intval = charger->battery_info->voltage_min_design;
> + break;
> + case POWER_SUPPLY_PROP_VOLTAGE_NOW:
> + val->intval = da9030_reg_to_mV(charger->adc.vbat_res) * 1000;
> + break;
> + case POWER_SUPPLY_PROP_CURRENT_AVG:
> + val->intval =
> + da9030_reg_to_mA(charger->adc.ichaverage_res) * 1000;
> + break;
> + case POWER_SUPPLY_PROP_MODEL_NAME:
> + val->strval = charger->battery_info->name;
> + break;
> + default:
> + break;
> + }
> +
> + return 0;
> +}
> +
> +static void da9030_battery_vbat_event(struct da9030_charger *charger)
> +{
> + da9030_read_adc(charger, &charger->adc);
> +
> + if (!charger->is_on) {

I'd write it as:

if (charger->is_on)
return;
the-rest;

Saves one indent level.

> + if (charger->adc.vbat_res < charger->thresholds.vbat_low) {
> + /* set VBAT threshold for critical */
> + da903x_write(charger->master, DA9030_VBATMON,
> + charger->thresholds.vbat_crit);
> + if (charger->battery_low)
> + charger->battery_low();
> + } else if (charger->adc.vbat_res <
> + charger->thresholds.vbat_crit) {
> + /* notify the system of battery critical */
> + if (charger->battery_critical)
> + charger->battery_critical();
> + }
> + }
> +}
> +
> +static int da9030_battery_event(struct notifier_block *nb, unsigned long event,
> + void *data)
> +{
> + struct da9030_charger *charger =
> + container_of(nb, struct da9030_charger, nb);
> + int status;
> +
> + switch (event) {
> + case DA9030_EVENT_CHDET:
> + status = da903x_query_status(charger->master,
> + DA9030_STATUS_CHDET);
> + da9030_set_charge(charger, status);
> + break;
> + case DA9030_EVENT_VBATMON:
> + da9030_battery_vbat_event(charger);
> + break;
> + case DA9030_EVENT_CHIOVER:
> + case DA9030_EVENT_TBAT:
> + da9030_set_charge(charger, 0);
> + break;
> + }
> +
> + return 0;
> +}
> +
> +static void da9030_battery_convert_thresholds(struct da9030_charger *charger,
> + struct da9030_battery_info *pdata)
> +{
> + charger->thresholds.tbat_low = pdata->tbat_low;
> + charger->thresholds.tbat_high = pdata->tbat_high;
> + charger->thresholds.tbat_restart = pdata->tbat_restart;
> +
> + charger->thresholds.vbat_low =
> + da9030_millivolt_to_reg(pdata->vbat_low);
> + charger->thresholds.vbat_crit =
> + da9030_millivolt_to_reg(pdata->vbat_crit);
> + charger->thresholds.vbat_charge_start =
> + da9030_millivolt_to_reg(pdata->vbat_charge_start);
> + charger->thresholds.vbat_charge_stop =
> + da9030_millivolt_to_reg(pdata->vbat_charge_stop);
> + charger->thresholds.vbat_charge_restart =
> + da9030_millivolt_to_reg(pdata->vbat_charge_restart);
> +
> + charger->thresholds.vcharge_min =
> + da9030_millivolt_to_reg(pdata->vcharge_min);
> + charger->thresholds.vcharge_max =
> + da9030_millivolt_to_reg(pdata->vcharge_max);
> +}
> +
> +static void da9030_battery_setup_psy(struct da9030_charger *charger)
> +{
> + struct power_supply *psy = &charger->psy;
> + struct power_supply_info *info = charger->battery_info;
> +
> + psy->name = info->name;
> + psy->use_for_apm = info->use_for_apm;
> + psy->type = POWER_SUPPLY_TYPE_BATTERY;
> + psy->get_property = da9030_battery_get_property;
> +
> + psy->properties = da9030_battery_props;
> + psy->num_properties = ARRAY_SIZE(da9030_battery_props);;

One semicolon is enough.

> +};
> +
> +static int da9030_battery_charger_init(struct da9030_charger *charger)
> +{
> + char v[5];
> + int ret;
> +
> + v[0] = v[1] = charger->thresholds.vbat_low;
> + v[2] = charger->thresholds.tbat_high;
> + v[3] = charger->thresholds.tbat_restart;
> + v[4] = charger->thresholds.tbat_low;
> +
> + ret = da903x_writes(charger->master, DA9030_VBATMON, 5, v);
> + if (ret)
> + return ret;
> +
> + /* enable reference voltage supply for ADC from the LDO_INTERNAL
> + regulator. Must be set before ADC measurements can be made. */

I would suggest using canonical-style comments:

/*
* Not a big deal though, I'm
* just nitpicking. ;-)
*/

Thanks,

--
Anton Vorontsov
email: cbouatmailru@xxxxxxxxx
irc://irc.freenode.net/bd2
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