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linux-next/drivers/power/tps65090-charger.c
Doug Anderson 193dcced04 charger: tps65090: Allow charger module to be used when no irq
On the ARM Chromebook tps65090 has two masters: the AP (the main
processor running linux) and the EC (the embedded controller).  The AP
is allowed to mess with FETs but the EC is in charge of charge control.

The tps65090 interupt line is routed to both the AP and the EC, which
can cause quite a headache.  Having two people adjusting masks and
acking interrupts is a recipe for disaster.

In the shipping kernel we had a hack to have the AP pay attention to
the IRQ but not to ack it.  It also wasn't supposed to configure the
IRQ in any way.  That hack allowed us to detect when the device was
charging without messing with the EC's state.

The current tps65090 infrastructure makes the above difficult, and it
was a bit of a hack to begin with.  Rather than uglify the driver to
support it, just extend the driver's existing notion of "no irq" to
the charger.  This makes the charger code poll every 2 seconds for AC
detect, which is sufficient.

For proper functioning, requires (mfd: tps65090: Don't tell child
devices we have an IRQ if we don't).  If we don't have that patch
we'll simply fail to probe on devices without an interrupt (just like
we did before this patch).

Signed-off-by: Doug Anderson <dianders@chromium.org>
Reviewed-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Tested-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
[sre@kernel.org: Use -ENXIO instead of NO_IRQ for missing interrupt,
since NO_IRQ is not available on all architectures.]
Signed-off-by: Sebastian Reichel <sre@kernel.org>
2014-07-18 23:40:23 +02:00

366 lines
8.9 KiB
C

/*
* Battery charger driver for TI's tps65090
*
* Copyright (c) 2013, NVIDIA CORPORATION. All rights reserved.
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
* This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
*/
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/freezer.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/kthread.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/slab.h>
#include <linux/mfd/tps65090.h>
#define TPS65090_CHARGER_ENABLE BIT(0)
#define TPS65090_VACG BIT(1)
#define TPS65090_NOITERM BIT(5)
#define POLL_INTERVAL (HZ * 2) /* Used when no irq */
struct tps65090_charger {
struct device *dev;
int ac_online;
int prev_ac_online;
int irq;
struct task_struct *poll_task;
bool passive_mode;
struct power_supply ac;
struct tps65090_platform_data *pdata;
};
static enum power_supply_property tps65090_ac_props[] = {
POWER_SUPPLY_PROP_ONLINE,
};
static int tps65090_low_chrg_current(struct tps65090_charger *charger)
{
int ret;
if (charger->passive_mode)
return 0;
ret = tps65090_write(charger->dev->parent, TPS65090_REG_CG_CTRL5,
TPS65090_NOITERM);
if (ret < 0) {
dev_err(charger->dev, "%s(): error reading in register 0x%x\n",
__func__, TPS65090_REG_CG_CTRL5);
return ret;
}
return 0;
}
static int tps65090_enable_charging(struct tps65090_charger *charger)
{
int ret;
uint8_t ctrl0 = 0;
if (charger->passive_mode)
return 0;
ret = tps65090_read(charger->dev->parent, TPS65090_REG_CG_CTRL0,
&ctrl0);
if (ret < 0) {
dev_err(charger->dev, "%s(): error reading in register 0x%x\n",
__func__, TPS65090_REG_CG_CTRL0);
return ret;
}
ret = tps65090_write(charger->dev->parent, TPS65090_REG_CG_CTRL0,
(ctrl0 | TPS65090_CHARGER_ENABLE));
if (ret < 0) {
dev_err(charger->dev, "%s(): error writing in register 0x%x\n",
__func__, TPS65090_REG_CG_CTRL0);
return ret;
}
return 0;
}
static int tps65090_config_charger(struct tps65090_charger *charger)
{
uint8_t intrmask = 0;
int ret;
if (charger->passive_mode)
return 0;
if (charger->pdata->enable_low_current_chrg) {
ret = tps65090_low_chrg_current(charger);
if (ret < 0) {
dev_err(charger->dev,
"error configuring low charge current\n");
return ret;
}
}
/* Enable the VACG interrupt for AC power detect */
ret = tps65090_read(charger->dev->parent, TPS65090_REG_INTR_MASK,
&intrmask);
if (ret < 0) {
dev_err(charger->dev, "%s(): error reading in register 0x%x\n",
__func__, TPS65090_REG_INTR_MASK);
return ret;
}
ret = tps65090_write(charger->dev->parent, TPS65090_REG_INTR_MASK,
(intrmask | TPS65090_VACG));
if (ret < 0) {
dev_err(charger->dev, "%s(): error writing in register 0x%x\n",
__func__, TPS65090_REG_CG_CTRL0);
return ret;
}
return 0;
}
static int tps65090_ac_get_property(struct power_supply *psy,
enum power_supply_property psp,
union power_supply_propval *val)
{
struct tps65090_charger *charger = container_of(psy,
struct tps65090_charger, ac);
if (psp == POWER_SUPPLY_PROP_ONLINE) {
val->intval = charger->ac_online;
charger->prev_ac_online = charger->ac_online;
return 0;
}
return -EINVAL;
}
static irqreturn_t tps65090_charger_isr(int irq, void *dev_id)
{
struct tps65090_charger *charger = dev_id;
int ret;
uint8_t status1 = 0;
uint8_t intrsts = 0;
ret = tps65090_read(charger->dev->parent, TPS65090_REG_CG_STATUS1,
&status1);
if (ret < 0) {
dev_err(charger->dev, "%s(): Error in reading reg 0x%x\n",
__func__, TPS65090_REG_CG_STATUS1);
return IRQ_HANDLED;
}
msleep(75);
ret = tps65090_read(charger->dev->parent, TPS65090_REG_INTR_STS,
&intrsts);
if (ret < 0) {
dev_err(charger->dev, "%s(): Error in reading reg 0x%x\n",
__func__, TPS65090_REG_INTR_STS);
return IRQ_HANDLED;
}
if (intrsts & TPS65090_VACG) {
ret = tps65090_enable_charging(charger);
if (ret < 0)
return IRQ_HANDLED;
charger->ac_online = 1;
} else {
charger->ac_online = 0;
}
/* Clear interrupts. */
if (!charger->passive_mode) {
ret = tps65090_write(charger->dev->parent,
TPS65090_REG_INTR_STS, 0x00);
if (ret < 0) {
dev_err(charger->dev,
"%s(): Error in writing reg 0x%x\n",
__func__, TPS65090_REG_INTR_STS);
}
}
if (charger->prev_ac_online != charger->ac_online)
power_supply_changed(&charger->ac);
return IRQ_HANDLED;
}
static struct tps65090_platform_data *
tps65090_parse_dt_charger_data(struct platform_device *pdev)
{
struct tps65090_platform_data *pdata;
struct device_node *np = pdev->dev.of_node;
unsigned int prop;
pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
if (!pdata) {
dev_err(&pdev->dev, "Memory alloc for tps65090_pdata failed\n");
return NULL;
}
prop = of_property_read_bool(np, "ti,enable-low-current-chrg");
pdata->enable_low_current_chrg = prop;
pdata->irq_base = -1;
return pdata;
}
static int tps65090_charger_poll_task(void *data)
{
set_freezable();
while (!kthread_should_stop()) {
schedule_timeout_interruptible(POLL_INTERVAL);
try_to_freeze();
tps65090_charger_isr(-1, data);
}
return 0;
}
static int tps65090_charger_probe(struct platform_device *pdev)
{
struct tps65090_charger *cdata;
struct tps65090_platform_data *pdata;
uint8_t status1 = 0;
int ret;
int irq;
pdata = dev_get_platdata(pdev->dev.parent);
if (IS_ENABLED(CONFIG_OF) && !pdata && pdev->dev.of_node)
pdata = tps65090_parse_dt_charger_data(pdev);
if (!pdata) {
dev_err(&pdev->dev, "%s():no platform data available\n",
__func__);
return -ENODEV;
}
cdata = devm_kzalloc(&pdev->dev, sizeof(*cdata), GFP_KERNEL);
if (!cdata) {
dev_err(&pdev->dev, "failed to allocate memory status\n");
return -ENOMEM;
}
platform_set_drvdata(pdev, cdata);
cdata->dev = &pdev->dev;
cdata->pdata = pdata;
cdata->ac.name = "tps65090-ac";
cdata->ac.type = POWER_SUPPLY_TYPE_MAINS;
cdata->ac.get_property = tps65090_ac_get_property;
cdata->ac.properties = tps65090_ac_props;
cdata->ac.num_properties = ARRAY_SIZE(tps65090_ac_props);
cdata->ac.supplied_to = pdata->supplied_to;
cdata->ac.num_supplicants = pdata->num_supplicants;
cdata->ac.of_node = pdev->dev.of_node;
ret = power_supply_register(&pdev->dev, &cdata->ac);
if (ret) {
dev_err(&pdev->dev, "failed: power supply register\n");
return ret;
}
irq = platform_get_irq(pdev, 0);
if (irq < 0)
irq = -ENXIO;
cdata->irq = irq;
ret = tps65090_config_charger(cdata);
if (ret < 0) {
dev_err(&pdev->dev, "charger config failed, err %d\n", ret);
goto fail_unregister_supply;
}
/* Check for charger presence */
ret = tps65090_read(cdata->dev->parent, TPS65090_REG_CG_STATUS1,
&status1);
if (ret < 0) {
dev_err(cdata->dev, "%s(): Error in reading reg 0x%x", __func__,
TPS65090_REG_CG_STATUS1);
goto fail_unregister_supply;
}
if (status1 != 0) {
ret = tps65090_enable_charging(cdata);
if (ret < 0) {
dev_err(cdata->dev, "error enabling charger\n");
goto fail_unregister_supply;
}
cdata->ac_online = 1;
power_supply_changed(&cdata->ac);
}
if (irq != -ENXIO) {
ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
tps65090_charger_isr, 0, "tps65090-charger", cdata);
if (ret) {
dev_err(cdata->dev,
"Unable to register irq %d err %d\n", irq,
ret);
goto fail_unregister_supply;
}
} else {
cdata->poll_task = kthread_run(tps65090_charger_poll_task,
cdata, "ktps65090charger");
cdata->passive_mode = true;
if (IS_ERR(cdata->poll_task)) {
ret = PTR_ERR(cdata->poll_task);
dev_err(cdata->dev,
"Unable to run kthread err %d\n", ret);
goto fail_unregister_supply;
}
}
return 0;
fail_unregister_supply:
power_supply_unregister(&cdata->ac);
return ret;
}
static int tps65090_charger_remove(struct platform_device *pdev)
{
struct tps65090_charger *cdata = platform_get_drvdata(pdev);
if (cdata->irq == -ENXIO)
kthread_stop(cdata->poll_task);
power_supply_unregister(&cdata->ac);
return 0;
}
static struct of_device_id of_tps65090_charger_match[] = {
{ .compatible = "ti,tps65090-charger", },
{ /* end */ }
};
static struct platform_driver tps65090_charger_driver = {
.driver = {
.name = "tps65090-charger",
.of_match_table = of_tps65090_charger_match,
.owner = THIS_MODULE,
},
.probe = tps65090_charger_probe,
.remove = tps65090_charger_remove,
};
module_platform_driver(tps65090_charger_driver);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Syed Rafiuddin <srafiuddin@nvidia.com>");
MODULE_DESCRIPTION("tps65090 battery charger driver");