Thanks for the review, fixed up what you suggested, I did leave one place as -EINVAL as it seemed the most appropriate for the spot. Will repost soon. -----Original Message----- From: Jean Delvare [mailto:khali@xxxxxxxxxxxx] Sent: Tuesday, August 31, 2010 1:24 AM To: Rhyland Klein Cc: cbouatmailru@xxxxxxxxx; linux-i2c@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; olof@xxxxxxxxx; Andrew Chew Subject: Re: [PATCH 1/1] power supply: add driver for TI BQ20Z75 gas gauge IC Hi Rhyland, On Fri, 27 Aug 2010 15:50:43 -0700, rklein@xxxxxxxxxx wrote: > From: Rhyland Klein <rklein@xxxxxxxxxx> > > this driver depends on I2C and uses SMBUS for communication with the host. Quick review (I am not familiar with the power supply API): > Signed-off-by: Rhyland Klein <rklein@xxxxxxxxxx> > --- > drivers/power/Kconfig | 7 + > drivers/power/Makefile | 1 + > drivers/power/bq20z75.c | 403 +++++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 411 insertions(+), 0 deletions(-) > create mode 100644 drivers/power/bq20z75.c > > diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig > index 8e9ba17..c72e628 100644 > --- a/drivers/power/Kconfig > +++ b/drivers/power/Kconfig > @@ -142,4 +142,11 @@ config CHARGER_PCF50633 > help > Say Y to include support for NXP PCF50633 Main Battery Charger. > > +config BQ20Z75_GASGAUGE Following the naming used for other options in this menu, this would be BATTERY_BQ20Z75. -Done > + tristate "TI BQ20Z75 GAS GAUGE" Not all capitals, please. -Fixed, changed to "TI BQ20z75 gas gauge" > + depends on I2C > + help > + Say Y to include support for TI BQ20Z75 SBS-compliant > + gas gauge and protection IC. > + > endif # POWER_SUPPLY > diff --git a/drivers/power/Makefile b/drivers/power/Makefile > index 0005080..98abc31 100644 > --- a/drivers/power/Makefile > +++ b/drivers/power/Makefile > @@ -34,3 +34,4 @@ obj-$(CONFIG_BATTERY_DA9030) += da9030_battery.o > obj-$(CONFIG_BATTERY_MAX17040) += max17040_battery.o > obj-$(CONFIG_BATTERY_Z2) += z2_battery.o > obj-$(CONFIG_CHARGER_PCF50633) += pcf50633-charger.o > +obj-$(CONFIG_BQ20Z75_GASGAUGE) += bq20z75.o > diff --git a/drivers/power/bq20z75.c b/drivers/power/bq20z75.c > new file mode 100644 > index 0000000..4eb6638 > --- /dev/null > +++ b/drivers/power/bq20z75.c > @@ -0,0 +1,403 @@ > +/* > + * drivers/power/bq20z75.c Please remove, this doesn't add much value and is likely to get outdated at some point. -Done > + * > + * Gas Gauge driver for TI's BQ20Z75 > + * > + * Copyright (c) 2010, NVIDIA Corporation. > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License as published by > + * the Free Software Foundation; either version 2 of the License, or > + * (at your option) any later version. > + * > + * This program is distributed in the hope that it will be useful, but WITHOUT > + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or > + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for > + * more details. > + * > + * You should have received a copy of the GNU General Public License along > + * with this program; if not, write to the Free Software Foundation, Inc., > + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. > + */ > + > +#include <linux/init.h> > +#include <linux/module.h> > +#include <linux/kernel.h> > +#include <linux/err.h> > +#include <linux/debugfs.h> I don't think you need this one? -Removed. > +#include <linux/power_supply.h> > +#include <linux/i2c.h> > +#include <linux/slab.h> > + > +enum { > + REG_MANUFACTURER_DATA, > + REG_TEMPERATURE, > + REG_VOLTAGE, > + REG_CURRENT, > + REG_CAPACITY, > + REG_TIME_TO_EMPTY, > + REG_TIME_TO_FULL, > + REG_STATUS, > + REG_CYCLE_COUNT, > + REG_SERIAL_NUMBER, > + REG_MAX > +}; > + > +#define BATTERY_MANUFACTURER_SIZE 12 > +#define BATTERY_NAME_SIZE 8 You don't use these anywhere? -Removed > + > +/* manufacturer access defines */ > +#define MANUFACTURER_ACCESS_STATUS 0x0006 > +#define MANUFACTURER_ACCESS_SLEEP 0x0011 > + > +/* battery status value bits */ > +#define BATTERY_CHARGING 0x40 > +#define BATTERY_FULL_CHARGED 0x20 > +#define BATTERY_FULL_DISCHARGED 0x10 > + > +#define BQ20Z75_DATA(_psp, _addr, _min_value, _max_value) { \ > + .psp = _psp, \ > + .addr = _addr, \ > + .min_value = _min_value, \ > + .max_value = _max_value, \ > +} > + > +static struct bq20z75_device_data { This could be const. -Done > + enum power_supply_property psp; > + u8 addr; > + int min_value; > + int max_value; > +} bq20z75_data[] = { > + [REG_MANUFACTURER_DATA] = > + BQ20Z75_DATA(POWER_SUPPLY_PROP_PRESENT, 0x00, 0, 65535), > + [REG_TEMPERATURE] = > + BQ20Z75_DATA(POWER_SUPPLY_PROP_TEMP, 0x08, 0, 65535), > + [REG_VOLTAGE] = > + BQ20Z75_DATA(POWER_SUPPLY_PROP_VOLTAGE_NOW, 0x09, 0, 20000), > + [REG_CURRENT] = > + BQ20Z75_DATA(POWER_SUPPLY_PROP_CURRENT_NOW, 0x0A, -32768, \ > + 32767), You don't need the backslash at the end of the line. -Removed > + [REG_CAPACITY] = > + BQ20Z75_DATA(POWER_SUPPLY_PROP_CAPACITY, 0x0e, 0, 100), Please be consistent with case in hexadecimal numbers. -Done > + [REG_TIME_TO_EMPTY] = > + BQ20Z75_DATA(POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG, 0x12, 0, \ > + 65535), > + [REG_TIME_TO_FULL] = > + BQ20Z75_DATA(POWER_SUPPLY_PROP_TIME_TO_FULL_AVG, 0x13, 0, \ > + 65535), > + [REG_STATUS] = > + BQ20Z75_DATA(POWER_SUPPLY_PROP_STATUS, 0x16, 0, 65535), > + [REG_CYCLE_COUNT] = > + BQ20Z75_DATA(POWER_SUPPLY_PROP_CYCLE_COUNT, 0x17, 0, 65535), > + [REG_SERIAL_NUMBER] = > + BQ20Z75_DATA(POWER_SUPPLY_PROP_SERIAL_NUMBER, 0x1C, 0, 65535), > +}; > + > +static enum power_supply_property bq20z75_properties[] = { > + POWER_SUPPLY_PROP_STATUS, > + POWER_SUPPLY_PROP_HEALTH, > + POWER_SUPPLY_PROP_PRESENT, > + POWER_SUPPLY_PROP_TECHNOLOGY, > + POWER_SUPPLY_PROP_CYCLE_COUNT, > + POWER_SUPPLY_PROP_VOLTAGE_NOW, > + POWER_SUPPLY_PROP_CURRENT_NOW, > + POWER_SUPPLY_PROP_CAPACITY, > + POWER_SUPPLY_PROP_TEMP, > + POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG, > + POWER_SUPPLY_PROP_TIME_TO_FULL_AVG, > + POWER_SUPPLY_PROP_SERIAL_NUMBER, > +}; > + > +static int bq20z75_get_property(struct power_supply *psy, > + enum power_supply_property psp, union power_supply_propval *val); > + > +static struct power_supply bq20z75_supply = { > + .name = "battery", > + .type = POWER_SUPPLY_TYPE_BATTERY, > + .properties = bq20z75_properties, > + .num_properties = ARRAY_SIZE(bq20z75_properties), > + .get_property = bq20z75_get_property, > +}; > + > +struct bq20z75_device_info { > + struct i2c_client *client; > +} *bq20z75_device; This structure doesn't seem terribly useful. You typically need the client to get to this information... And storing the device pointer as a global is evil anyway, please don't do that. TODO: > + > +static int bq20z75_get_battery_presence_and_health( > + enum power_supply_property psp, union power_supply_propval *val) > +{ > + s32 ret; > + > + /* Write to ManufacturerAccess with > + * ManufacturerAccess command and then > + * read the status */ > + ret = i2c_smbus_write_word_data(bq20z75_device->client, > + bq20z75_data[REG_MANUFACTURER_DATA].addr, > + MANUFACTURER_ACCESS_STATUS); > + if (ret < 0) { > + dev_err(&bq20z75_device->client->dev, > + "%s: i2c write for battery presence failed\n", > + __func__); > + return -EINVAL; > + } > + > + ret = i2c_smbus_read_word_data(bq20z75_device->client, > + bq20z75_data[REG_MANUFACTURER_DATA].addr); > + if (ret < 0) { > + dev_err(&bq20z75_device->client->dev, > + "%s: i2c read for battery presence failed\n", > + __func__); > + return -EINVAL; > + } -EINVAL doesn't look like the right error code. -ENODEV or -EIO would seem more appropriate. Same issue several times, please address them all. -Done, only one place seemed to make sense for EINVAL, the default case where it was an unknown property, does that makes sense to you? > + > + if (ret < bq20z75_data[REG_MANUFACTURER_DATA].min_value || > + ret > bq20z75_data[REG_MANUFACTURER_DATA].max_value) { > + val->intval = 0; > + return 0; > + } > + > + /* Mask the upper nibble of 2nd byte and > + * lower byte of response then > + * shift the result by 8 to get status*/ > + ret &= 0x0F00; > + ret >>= 8; > + if (psp == POWER_SUPPLY_PROP_PRESENT) { > + if (ret == 0x0F) > + /* battery removed */ > + val->intval = 0; > + else > + val->intval = 1; > + } else if (psp == POWER_SUPPLY_PROP_HEALTH) { > + if (ret == 0x09) > + val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE; > + else if (ret == 0x0B) > + val->intval = POWER_SUPPLY_HEALTH_OVERHEAT; > + else if (ret == 0x0C) > + val->intval = POWER_SUPPLY_HEALTH_DEAD; > + else > + val->intval = POWER_SUPPLY_HEALTH_GOOD; > + } > + > + return 0; > +} > + > +static int bq20z75_get_battery_property(int reg_offset, > + enum power_supply_property psp, > + union power_supply_propval *val) > +{ > + s32 ret; > + > + ret = i2c_smbus_read_word_data(bq20z75_device->client, > + bq20z75_data[reg_offset].addr); > + if (ret < 0) { > + dev_err(&bq20z75_device->client->dev, > + "%s: i2c read for %d failed\n", __func__, reg_offset); > + return -EINVAL; > + } > + > + if (ret >= bq20z75_data[reg_offset].min_value && > + ret <= bq20z75_data[reg_offset].max_value) { > + val->intval = ret; > + if (psp == POWER_SUPPLY_PROP_STATUS) { > + /* mask the upper byte and then find the > + * actual status */ > + ret &= 0x00FF; As far as I can see, this masking is a no-op. -Removed > + if (ret & BATTERY_CHARGING) > + val->intval = POWER_SUPPLY_STATUS_CHARGING; > + else if (ret & BATTERY_FULL_CHARGED) > + val->intval = POWER_SUPPLY_STATUS_FULL; > + else if (ret & BATTERY_FULL_DISCHARGED) > + val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING; > + else > + val->intval = POWER_SUPPLY_STATUS_DISCHARGING; > + } > + /* bq20z75 provides battery tempreture in 0.1°K > + * so convert it to °C */ > + else if (psp == POWER_SUPPLY_PROP_TEMP) > + val->intval = ret - 2731; > + } else { > + val->intval = 0; This should be moved... > + if (psp == POWER_SUPPLY_PROP_STATUS) > + val->intval = POWER_SUPPLY_STATUS_UNKNOWN; ... here, with a else. -Done > + } > + > + return 0; > +} > + > +static int bq20z75_get_battery_capacity(union power_supply_propval *val) > +{ > + s32 ret; > + > + ret = i2c_smbus_read_byte_data(bq20z75_device->client, > + bq20z75_data[REG_CAPACITY].addr); > + if (ret < 0) { > + dev_err(&bq20z75_device->client->dev, > + "%s: i2c read for %d failed\n", __func__, REG_CAPACITY); > + return -EINVAL; > + } > + > + /* bq20z75 spec says that this can be >100 % > + * even if max value is 100 % */ > + val->intval = ((ret >= 100) ? 100 : ret); Can also be written min(ret, 100). -Done :) > + > + return 0; > +} > + > +static int bq20z75_get_property(struct power_supply *psy, > + enum power_supply_property psp, > + union power_supply_propval *val) > +{ > + u8 count; For loops like int better. -Done > + > + switch (psp) { > + case POWER_SUPPLY_PROP_PRESENT: > + case POWER_SUPPLY_PROP_HEALTH: > + if (bq20z75_get_battery_presence_and_health(psp, val)) > + return -EINVAL; You should pass down the exact error value returned by the function, instead of hardcoding it. Same below. -Done > + break; > + > + case POWER_SUPPLY_PROP_TECHNOLOGY: > + val->intval = POWER_SUPPLY_TECHNOLOGY_LION; > + break; > + > + case POWER_SUPPLY_PROP_CAPACITY: > + if (bq20z75_get_battery_capacity(val)) > + return -EINVAL; > + break; > + > + case POWER_SUPPLY_PROP_STATUS: > + case POWER_SUPPLY_PROP_CYCLE_COUNT: > + case POWER_SUPPLY_PROP_VOLTAGE_NOW: > + case POWER_SUPPLY_PROP_CURRENT_NOW: > + case POWER_SUPPLY_PROP_TEMP: > + case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG: > + case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG: > + case POWER_SUPPLY_PROP_SERIAL_NUMBER: > + for (count = 0; count < REG_MAX; count++) { > + if (psp == bq20z75_data[count].psp) > + break; > + } > + > + if (bq20z75_get_battery_property(count, psp, val)) > + return -EINVAL; > + break; Wrong indentation. -Done > + > + default: > + dev_err(&bq20z75_device->client->dev, > + "%s: INVALID property\n", __func__); > + return -EINVAL; > + } > + > + printk(KERN_INFO "%s: property = %d, value = %d\n", __func__, > + psp, val->intval); Should be turned into dev_dbg(). -Done > + > + return 0; > +} > + > +static int bq20z75_probe(struct i2c_client *client, > + const struct i2c_device_id *id) > +{ > + int rc; > + > + bq20z75_device = kzalloc(sizeof(*bq20z75_device), GFP_KERNEL); > + if (!bq20z75_device) > + return -ENOMEM; > + > +memset(bq20z75_device, 0, sizeof(*bq20z75_device)); Wrong indentation, and useless code, as kzalloc did it for you already. -Removed > + > + bq20z75_device->client = client; > + i2c_set_clientdata(client, bq20z75_device); > + > + rc = power_supply_register(&client->dev, &bq20z75_supply); > + if (rc) { > + dev_err(&bq20z75_device->client->dev, > + "%s: Failed to register power supply\n", __func__); > + kfree(bq20z75_device); > + return rc; > + } > + > + dev_info(&bq20z75_device->client->dev, > + "%s: battery driver registered\n", client->name); What you did here is register a device, not a driver. -changed to "battery gas gauge device registered" > + > + return 0; > +} > + > +static int bq20z75_remove(struct i2c_client *client) > +{ > + struct bq20z75_device_info *bq20z75_device = i2c_get_clientdata(client); > + > + power_supply_unregister(&bq20z75_supply); > + kfree(bq20z75_device); > + bq20z75_device = NULL; > + > + return 0; > +} > + > +#if defined CONFIG_PM > +static int bq20z75_suspend(struct i2c_client *client, > + pm_message_t state) > +{ > + s32 ret; > + struct bq20z75_device_info *bq20z75_device = i2c_get_clientdata(client); You get the data from the client... > + > + /* write to manufacture access with sleep command */ (typo: manufacturer) -Fixed > + ret = i2c_smbus_write_word_data(bq20z75_device->client, ... just to get the client from the data. Terribly efficient ;) -Done > + bq20z75_data[REG_MANUFACTURER_DATA].addr, > + MANUFACTURER_ACCESS_SLEEP); > + if (ret < 0) { > + dev_err(&bq20z75_device->client->dev, > + "%s: i2c write for %d failed\n", > + __func__, MANUFACTURER_ACCESS_SLEEP); > + return -EINVAL; > + } > + > + return 0; > +} > + > +/* any smbus transaction will wake up bq20z75 */ > +static int bq20z75_resume(struct i2c_client *client) > +{ > + return 0; > +} > +#endif > + > +static const struct i2c_device_id bq20z75_id[] = { > + { "bq20z75-battery", 0 }, "-battery" is redundant, just use "bq20z75". -Done > + {}, Needless comma. -Removed > +}; > + > +static struct i2c_driver bq20z75_battery_driver = { > + .probe = bq20z75_probe, > + .remove = bq20z75_remove, > +#if defined CONFIG_PM > + .suspend = bq20z75_suspend, > + .resume = bq20z75_resume, > +#endif > + .id_table = bq20z75_id, > + .driver = { > + .name = "bq20z75-battery", > + }, > +}; > + > +static int __init bq20z75_battery_init(void) > +{ > + int ret; > + > + ret = i2c_add_driver(&bq20z75_battery_driver); > + if (ret) > + dev_err(&bq20z75_device->client->dev, > + "%s: i2c_add_driver failed\n", __func__); This is essentially needless. The kernel will log the failure already. -Fixed up > + > + return ret; > +} > +module_init(bq20z75_battery_init); > + > +static void __exit bq20z75_battery_exit(void) > +{ > + i2c_del_driver(&bq20z75_battery_driver); > +} > +module_exit(bq20z75_battery_exit); > + > +MODULE_AUTHOR("NVIDIA Graphics Pvt Ltd"); > +MODULE_DESCRIPTION("BQ20z75 battery monitor driver"); > +MODULE_LICENSE("GPL"); -- Jean Delvare ��.n��������+%������w��{.n�����{��-��)�� jg��� �����ݢj����G���� ���j:+v���w�m������w�������h�����٥
