[PATCH] power: bq20z75: change to platform driver

From: rklein
Date: Mon Feb 14 2011 - 14:27:16 EST

From: Rhyland Klein <rklein@xxxxxxxxxx>

This change switches the bq20z75 i2c driver into a platform driver
and adds support for an optional battery detect gpio. Now the driver also
signals when the battery is inserted or removed.

I also added a retry mechanism so that for boards where there may be
intermittent i2c issues, retries can be used to avoid spurious failures.

Signed-off-by: Rhyland Klein <rklein@xxxxxxxxxx>
---
drivers/power/bq20z75.c | 282 ++++++++++++++++++++++++++++++++---------
include/linux/power/bq20z75.h | 39 ++++++
2 files changed, 258 insertions(+), 63 deletions(-)
create mode 100644 include/linux/power/bq20z75.h

diff --git a/drivers/power/bq20z75.c b/drivers/power/bq20z75.c
index 4141775..9b9269e 100644
--- a/drivers/power/bq20z75.c
+++ b/drivers/power/bq20z75.c
@@ -25,6 +25,11 @@
#include <linux/power_supply.h>
#include <linux/i2c.h>
#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/gpio.h>
+
+#include <linux/power/bq20z75.h>

enum {
REG_MANUFACTURER_DATA,
@@ -141,17 +146,30 @@ static enum power_supply_property bq20z75_properties[] = {
};

struct bq20z75_info {
- struct i2c_client *client;
- struct power_supply power_supply;
+ struct i2c_client *client;
+ struct i2c_adapter *adapter;
+ struct power_supply power_supply;
+ bool is_present;
+ struct bq20z75_platform_data *pdata;
+ struct platform_device *pdev;
+ bool gpio_detect;
+ int irq;
+ bool enable_detection;
};

static int bq20z75_read_word_data(struct i2c_client *client, u8 address)
{
- s32 ret;
+ s32 ret = 0;
+ struct bq20z75_info *bq20z75_device = i2c_get_clientdata(client);
+ int retries = max(bq20z75_device->pdata->i2c_retry_count+1, 1);

- ret = i2c_smbus_read_word_data(client, address);
+ while (retries > 0) {
+ ret = i2c_smbus_read_word_data(client, address);
+ if (ret >= 0)
+ break;
+ }
if (ret < 0) {
- dev_err(&client->dev,
+ dev_warn(&bq20z75_device->pdev->dev,
"%s: i2c read at address 0x%x failed\n",
__func__, address);
return ret;
@@ -162,15 +180,24 @@ static int bq20z75_read_word_data(struct i2c_client *client, u8 address)
static int bq20z75_write_word_data(struct i2c_client *client, u8 address,
u16 value)
{
- s32 ret;
-
- ret = i2c_smbus_write_word_data(client, address, le16_to_cpu(value));
+ s32 ret = 0;
+ struct bq20z75_info *bq20z75_device = i2c_get_clientdata(client);
+ int retries = max(bq20z75_device->pdata->i2c_retry_count+1, 1);
+
+ while (retries > 0) {
+ ret = i2c_smbus_write_word_data(client, address,
+ le16_to_cpu(value));
+ if (ret >= 0)
+ break;
+ retries--;
+ }
if (ret < 0) {
- dev_err(&client->dev,
+ dev_warn(&bq20z75_device->pdev->dev,
"%s: i2c write to address 0x%x failed\n",
__func__, address);
return ret;
}
+
return 0;
}

@@ -179,7 +206,15 @@ static int bq20z75_get_battery_presence_and_health(
union power_supply_propval *val)
{
s32 ret;
+ struct bq20z75_info *bq20z75_device = i2c_get_clientdata(client);

+ if (psp == POWER_SUPPLY_PROP_PRESENT &&
+ bq20z75_device->gpio_detect) {
+ ret = gpio_get_value(
+ bq20z75_device->pdata->battery_detect);
+ val->intval = (ret == 0 ? 1 : 0);
+ return ret;
+ }
/* Write to ManufacturerAccess with
* ManufacturerAccess command and then
* read the status */
@@ -189,12 +224,15 @@ static int bq20z75_get_battery_presence_and_health(
if (ret < 0)
return ret;

-
ret = bq20z75_read_word_data(client,
bq20z75_data[REG_MANUFACTURER_DATA].addr);
- if (ret < 0)
+ if (ret < 0) {
+ if (psp == POWER_SUPPLY_PROP_PRESENT)
+ val->intval = 0; /* battery removed */
return ret;

+ }
+
if (ret < bq20z75_data[REG_MANUFACTURER_DATA].min_value ||
ret > bq20z75_data[REG_MANUFACTURER_DATA].max_value) {
val->intval = 0;
@@ -271,6 +309,8 @@ static void bq20z75_unit_adjustment(struct i2c_client *client,
#define BATTERY_MODE_CAP_MULT_WATT (10 * BASE_UNIT_CONVERSION)
#define TIME_UNIT_CONVERSION 600
#define TEMP_KELVIN_TO_CELCIUS 2731
+ struct bq20z75_info *bq20z75_device = i2c_get_clientdata(client);
+
switch (psp) {
case POWER_SUPPLY_PROP_ENERGY_NOW:
case POWER_SUPPLY_PROP_ENERGY_FULL:
@@ -300,7 +340,7 @@ static void bq20z75_unit_adjustment(struct i2c_client *client,
break;

default:
- dev_dbg(&client->dev,
+ dev_dbg(&bq20z75_device->pdev->dev,
"%s: no need for unit conversion %d\n", __func__, psp);
}
}
@@ -348,11 +388,11 @@ static int bq20z75_get_battery_capacity(struct i2c_client *client,
if (ret < 0)
return ret;

- if (psp == POWER_SUPPLY_PROP_CAPACITY) {
- /* bq20z75 spec says that this can be >100 %
- * even if max value is 100 % */
+ /* bq20z75 spec says that this can be >100 %
+ * even if max value is 100 % */
+ if (psp == POWER_SUPPLY_PROP_CAPACITY)
val->intval = min(ret, 100);
- } else
+ else
val->intval = ret;

ret = bq20z75_set_battery_mode(client, mode);
@@ -383,11 +423,13 @@ static int bq20z75_get_property_index(struct i2c_client *client,
enum power_supply_property psp)
{
int count;
+ struct bq20z75_info *bq20z75_device = i2c_get_clientdata(client);
+
for (count = 0; count < ARRAY_SIZE(bq20z75_data); count++)
if (psp == bq20z75_data[count].psp)
return count;

- dev_warn(&client->dev,
+ dev_warn(&bq20z75_device->pdev->dev,
"%s: Invalid Property - %d\n", __func__, psp);

return -EINVAL;
@@ -398,7 +440,7 @@ static int bq20z75_get_property(struct power_supply *psy,
union power_supply_propval *val)
{
int ps_index;
- int ret;
+ int ret = 0;
struct bq20z75_info *bq20z75_device = container_of(psy,
struct bq20z75_info, power_supply);
struct i2c_client *client = bq20z75_device->client;
@@ -407,8 +449,6 @@ static int bq20z75_get_property(struct power_supply *psy,
case POWER_SUPPLY_PROP_PRESENT:
case POWER_SUPPLY_PROP_HEALTH:
ret = bq20z75_get_battery_presence_and_health(client, psp, val);
- if (ret)
- return ret;
break;

case POWER_SUPPLY_PROP_TECHNOLOGY:
@@ -423,19 +463,16 @@ static int bq20z75_get_property(struct power_supply *psy,
case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
case POWER_SUPPLY_PROP_CAPACITY:
ps_index = bq20z75_get_property_index(client, psp);
- if (ps_index < 0)
- return ps_index;
+ if (ps_index < 0) {
+ ret = ps_index;
+ break;
+ }

ret = bq20z75_get_battery_capacity(client, ps_index, psp, val);
- if (ret)
- return ret;
-
break;

case POWER_SUPPLY_PROP_SERIAL_NUMBER:
ret = bq20z75_get_battery_serial_number(client, val);
- if (ret)
- return ret;
break;

case POWER_SUPPLY_PROP_STATUS:
@@ -447,41 +484,76 @@ static int bq20z75_get_property(struct power_supply *psy,
case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
ps_index = bq20z75_get_property_index(client, psp);
- if (ps_index < 0)
- return ps_index;
+ if (ps_index < 0) {
+ ret = ps_index;
+ break;
+ }

ret = bq20z75_get_battery_property(client, ps_index, psp, val);
- if (ret)
- return ret;
-
break;

default:
- dev_err(&client->dev,
+ dev_err(&bq20z75_device->pdev->dev,
"%s: INVALID property\n", __func__);
return -EINVAL;
}

- /* Convert units to match requirements for power supply class */
- bq20z75_unit_adjustment(client, psp, val);
+ if (!bq20z75_device->enable_detection)
+ goto done;
+
+ if (!bq20z75_device->gpio_detect &&
+ bq20z75_device->is_present != (ret >= 0)) {
+ bq20z75_device->is_present = (ret >= 0);
+ power_supply_changed(&bq20z75_device->power_supply);
+ }

- dev_dbg(&client->dev,
+done:
+ if (!ret) {
+ /* Convert units to match requirements for power supply class */
+ bq20z75_unit_adjustment(client, psp, val);
+ }
+
+ dev_dbg(&bq20z75_device->pdev->dev,
"%s: property = %d, value = %d\n", __func__, psp, val->intval);

- return 0;
+ return ret;
}

-static int bq20z75_probe(struct i2c_client *client,
- const struct i2c_device_id *id)
+static irqreturn_t bq20z75_irq(int irq, void *devid)
+{
+ struct power_supply *battery = devid;
+
+ power_supply_changed(battery);
+
+ return IRQ_HANDLED;
+}
+
+static struct i2c_board_info __initdata bq20z75_i2c_device = {
+ I2C_BOARD_INFO("bq20z75", 0x0b),
+};
+
+static int __devinit bq20z75_probe(struct platform_device *pdev)
{
struct bq20z75_info *bq20z75_device;
int rc;
+ struct bq20z75_platform_data *pdata = pdev->dev.platform_data;
+ int irq;
+ struct i2c_adapter *adapter;
+ struct i2c_client *client;
+
+ if (!pdata) {
+ dev_err(&pdev->dev, "No platform data\n");
+ return -EINVAL;
+ }

bq20z75_device = kzalloc(sizeof(struct bq20z75_info), GFP_KERNEL);
if (!bq20z75_device)
return -ENOMEM;

- bq20z75_device->client = client;
+ bq20z75_device->gpio_detect = gpio_is_valid(pdata->battery_detect);
+ bq20z75_device->pdata = pdata;
+ bq20z75_device->enable_detection = false;
+ bq20z75_device->pdev = pdev;
bq20z75_device->power_supply.name = "battery";
bq20z75_device->power_supply.type = POWER_SUPPLY_TYPE_BATTERY;
bq20z75_device->power_supply.properties = bq20z75_properties;
@@ -489,27 +561,116 @@ static int bq20z75_probe(struct i2c_client *client,
ARRAY_SIZE(bq20z75_properties);
bq20z75_device->power_supply.get_property = bq20z75_get_property;

+ platform_set_drvdata(pdev, &bq20z75_device);
+
+ if (!bq20z75_device->gpio_detect)
+ goto skip_gpio;
+
+ rc = gpio_request(pdata->battery_detect, dev_name(&pdev->dev));
+ if (rc) {
+ dev_warn(&pdev->dev, "Failed to request gpio: %d\n", rc);
+ bq20z75_device->gpio_detect = false;
+ goto skip_gpio;
+ }
+
+ rc = gpio_direction_input(pdata->battery_detect);
+ if (rc) {
+ dev_warn(&pdev->dev, "Failed to get gpio as input: %d\n", rc);
+ gpio_free(pdata->battery_detect);
+ bq20z75_device->gpio_detect = false;
+ goto skip_gpio;
+ }
+
+ irq = gpio_to_irq(pdata->battery_detect);
+ if (irq <= 0) {
+ gpio_free(pdata->battery_detect);
+ bq20z75_device->gpio_detect = false;
+ goto skip_gpio;
+ }
+
+ rc = request_irq(irq, bq20z75_irq,
+ IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
+ dev_name(&pdev->dev), &bq20z75_device->power_supply);
+ if (rc) {
+ dev_warn(&pdev->dev, "Failed to request irq: %d\n", rc);
+ gpio_free(pdata->battery_detect);
+ bq20z75_device->gpio_detect = false;
+ }
+
+ bq20z75_device->irq = irq;
+
+skip_gpio:
+ adapter = i2c_get_adapter(pdata->bus);
+ if (!adapter) {
+ dev_err(&pdev->dev, "Failed to get I2C adapter\n");
+ rc = -EINVAL;
+ goto exit_adapter;
+ }
+
+ client = i2c_new_device(adapter, &bq20z75_i2c_device);
+ if (!client) {
+ dev_err(&pdev->dev, "Failed to create I2C device\n");
+ rc = -EINVAL;
+ goto exit_device;
+ }
+
+ bq20z75_device->adapter = adapter;
+ bq20z75_device->client = client;
i2c_set_clientdata(client, bq20z75_device);

- rc = power_supply_register(&client->dev, &bq20z75_device->power_supply);
+ rc = power_supply_register(&pdev->dev, &bq20z75_device->power_supply);
if (rc) {
- dev_err(&client->dev,
+ dev_err(&pdev->dev,
"%s: Failed to register power supply\n", __func__);
- kfree(bq20z75_device);
- return rc;
+ goto exit_psupply;
}

- dev_info(&client->dev,
+ /* NOW check if initially present */
+ if (bq20z75_device->gpio_detect) {
+ int present = gpio_get_value(pdata->battery_detect);
+ bq20z75_device->is_present = (present == 0);
+ } else {
+ union power_supply_propval val;
+ bq20z75_get_battery_presence_and_health(client,
+ POWER_SUPPLY_PROP_PRESENT, &val);
+ bq20z75_device->is_present = (val.intval != 0);
+ }
+ bq20z75_device->enable_detection = true;
+
+ dev_info(&pdev->dev,
"%s: battery gas gauge device registered\n", client->name);

return 0;
+exit_psupply:
+ i2c_unregister_device(client);
+exit_device:
+ i2c_put_adapter(adapter);
+exit_adapter:
+ if (bq20z75_device->irq)
+ free_irq(bq20z75_device->irq, &bq20z75_device->power_supply);
+ if (bq20z75_device->gpio_detect)
+ gpio_free(pdata->battery_detect);
+
+ kfree(bq20z75_device);
+ return rc;
}

-static int bq20z75_remove(struct i2c_client *client)
+static int __devexit bq20z75_remove(struct platform_device *pdev)
{
- struct bq20z75_info *bq20z75_device = i2c_get_clientdata(client);
+ struct bq20z75_info *bq20z75_device = platform_get_drvdata(pdev);

power_supply_unregister(&bq20z75_device->power_supply);
+
+ if (bq20z75_device->irq)
+ free_irq(bq20z75_device->irq, &bq20z75_device->power_supply);
+
+ if (bq20z75_device->gpio_detect)
+ gpio_free(bq20z75_device->pdata->battery_detect);
+
+ i2c_unregister_device(bq20z75_device->client);
+ i2c_put_adapter(bq20z75_device->adapter);
+
+ platform_set_drvdata(pdev, NULL);
kfree(bq20z75_device);
bq20z75_device = NULL;

@@ -517,13 +678,14 @@ static int bq20z75_remove(struct i2c_client *client)
}

#if defined CONFIG_PM
-static int bq20z75_suspend(struct i2c_client *client,
+static int bq20z75_suspend(struct platform_device *pdev,
pm_message_t state)
{
+ struct bq20z75_info *bq20z75_device = platform_get_drvdata(pdev);
s32 ret;

/* write to manufacturer access with sleep command */
- ret = bq20z75_write_word_data(client,
+ ret = bq20z75_write_word_data(bq20z75_device->client,
bq20z75_data[REG_MANUFACTURER_DATA].addr,
MANUFACTURER_ACCESS_SLEEP);
if (ret < 0)
@@ -537,33 +699,27 @@ static int bq20z75_suspend(struct i2c_client *client,
/* any smbus transaction will wake up bq20z75 */
#define bq20z75_resume NULL

-static const struct i2c_device_id bq20z75_id[] = {
- { "bq20z75", 0 },
- {}
-};
-
-static struct i2c_driver bq20z75_battery_driver = {
+static struct platform_driver bq20z75_driver = {
.probe = bq20z75_probe,
- .remove = bq20z75_remove,
+ .remove = __devexit_p(bq20z75_remove),
.suspend = bq20z75_suspend,
.resume = bq20z75_resume,
- .id_table = bq20z75_id,
.driver = {
.name = "bq20z75-battery",
},
};

-static int __init bq20z75_battery_init(void)
+static int __init bq20z75_init(void)
{
- return i2c_add_driver(&bq20z75_battery_driver);
+ return platform_driver_register(&bq20z75_driver);
}
-module_init(bq20z75_battery_init);
+module_init(bq20z75_init);

-static void __exit bq20z75_battery_exit(void)
+static void __exit bq20z75_exit(void)
{
- i2c_del_driver(&bq20z75_battery_driver);
+ platform_driver_unregister(&bq20z75_driver);
}
-module_exit(bq20z75_battery_exit);
+module_exit(bq20z75_exit);

MODULE_DESCRIPTION("BQ20z75 battery monitor driver");
MODULE_LICENSE("GPL");
diff --git a/include/linux/power/bq20z75.h b/include/linux/power/bq20z75.h
new file mode 100644
index 0000000..53529f0
--- /dev/null
+++ b/include/linux/power/bq20z75.h
@@ -0,0 +1,39 @@
+/*
+ * 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.
+ */
+
+#ifndef __LINUX_POWER_BQ20Z75_H_
+#define __LINUX_POWER_BQ20Z75_H_
+
+#include <linux/power_supply.h>
+#include <linux/types.h>
+
+/**
+ * struct bq20z75_platform_data - platform data for bq20z75 devices
+ * @battery_detect: GPIO which is used to detect battery presence
+ * @i2c_retry_count: # of times to retry on i2c io failure
+ * @bus: i2c bus number
+ */
+struct bq20z75_platform_data {
+ int battery_detect;
+ int i2c_retry_count;
+ int bus;
+};
+
+#endif
--
1.7.0.4

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