[PATCH v5 6/6] power: supply: sbs-manager: Add alert callback and battery change notification.

Phil Reid
2016-09-21T08:41:29Z

This adds irq support via the smbus_alert driver to generate
power_supply_changed notifications when either external power is
removed / applied or a battery inserted / removed.
Uuse the i2c alert callback to notify the attached battery driver that a
change has occurred.

Signed-off-by: Phil Reid <preid@electromag.com.au>
---
drivers/power/supply/sbs-manager.c | 134 ++++++++++++++++++++++++++++++++++++-
1 file changed, 131 insertions(+), 3 deletions(-)

diff --git a/drivers/power/supply/sbs-manager.c b/drivers/power/supply/sbs-manager.c
index e3debd7..9b92b40 100644
--- a/drivers/power/supply/sbs-manager.c
+++ b/drivers/power/supply/sbs-manager.c
@@ -19,6 +19,7 @@
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/i2c-mux.h>
+#include <linux/gpio.h>
#include <linux/power_supply.h>

#define SBSM_MAX_BATS 4
@@ -30,14 +31,22 @@
#define SBSM_CMD_BATSYSINFO 0x04
#define SBSM_CMD_LTC 0x3c

+#define SBSM_BIT_AC_PRESENT BIT(0)
+
struct sbsm_data {
struct i2c_client *client;
struct i2c_mux_core *muxc;

struct power_supply *psy;

+ struct gpio_chip chip;
+
int cur_chan; /* currently selected channel */
bool is_ltc1760; /* special capabilities */
+
+ unsigned int supported_bats;
+ unsigned int last_state;
+ unsigned int last_state_cont;
};

static enum power_supply_property sbsm_props[] = {
@@ -184,6 +193,121 @@ static int sbsm_select(struct i2c_mux_core *muxc, u32 chan)
return ret;
}

+static int sbsm_gpio_get_value(struct gpio_chip *gc, unsigned off)
+{
+ struct sbsm_data *data = gpiochip_get_data(gc);
+ int ret;
+
+ ret = sbsm_read_word(data->client, SBSM_CMD_BATSYSSTATE);
+ if (ret < 0)
+ return ret;
+
+ return ret & BIT(off);
+}
+
+/*
+* This needs to be defined or the GPIO lib fails to register the pin.
+* But the 'gpio' is always an input.
+*/
+static int sbsm_gpio_direction_input(struct gpio_chip *gc, unsigned off)
+{
+ return 0;
+}
+
+static int sbsm_do_alert(struct device *dev, void *d)
+{
+ struct i2c_client *client = i2c_verify_client(dev);
+ struct i2c_driver *driver;
+
+ if (!client || client->addr != 0x0b)
+ return 0;
+
+ /*
+ * Drivers should either disable alerts, or provide at least
+ * a minimal handler. Lock so the driver won't change.
+ */
+ device_lock(dev);
+ if (client->dev.driver) {
+ driver = to_i2c_driver(client->dev.driver);
+ if (driver->alert)
+ driver->alert(client, I2C_PROTOCOL_SMBUS_ALERT, 0);
+ else
+ dev_warn(&client->dev, "no driver alert()!\n");
+ } else
+ dev_dbg(&client->dev, "alert with no driver\n");
+ device_unlock(dev);
+
+ /* Stop iterating after we find the device */
+ return -EBUSY;
+}
+
+void sbsm_alert(struct i2c_client *client, enum i2c_alert_protocol prot,
+ unsigned int d)
+{
+ struct sbsm_data *sbsm = i2c_get_clientdata(client);
+
+ int ret, i, irq_bat = 0;
+
+ ret = sbsm_read_word(sbsm->client, SBSM_CMD_BATSYSSTATE);
+ if (ret >= 0)
+ irq_bat = ret ^ sbsm->last_state;
+ sbsm->last_state = ret;
+
+ ret = sbsm_read_word(sbsm->client, SBSM_CMD_BATSYSSTATECONT);
+ if ((ret >= 0) &&
+ ((ret ^ sbsm->last_state_cont) & SBSM_BIT_AC_PRESENT)) {
+ irq_bat |= sbsm->supported_bats;
+ power_supply_changed(sbsm->psy);
+ }
+ sbsm->last_state_cont = ret;
+
+ for (i = 0; i < SBSM_MAX_BATS; i++) {
+ if (irq_bat & BIT(i)) {
+ device_for_each_child(&sbsm->muxc->adapter[i]->dev, 0,
+ sbsm_do_alert);
+ }
+ }
+}
+
+static int sbsm_gpio_setup(struct sbsm_data *data)
+{
+ struct gpio_chip *gc = &data->chip;
+ struct i2c_client *client = data->client;
+ struct device *dev = &client->dev;
+ struct device_node *of_node = client->dev.of_node;
+ int ret;
+
+ if (!of_get_property(of_node, "gpio-controller", NULL))
+ return 0;
+
+ ret = sbsm_read_word(client, SBSM_CMD_BATSYSSTATE);
+ if (ret < 0)
+ return ret;
+ data->last_state = ret;
+
+ ret = sbsm_read_word(client, SBSM_CMD_BATSYSSTATECONT);
+ if (ret < 0)
+ return ret;
+ data->last_state_cont = ret;
+
+ gc->get = sbsm_gpio_get_value;
+ gc->direction_input = sbsm_gpio_direction_input;
+ gc->can_sleep = true;
+ gc->base = -1;
+ gc->ngpio = SBSM_MAX_BATS;
+ gc->label = client->name;
+ gc->parent = dev;
+ gc->owner = THIS_MODULE;
+
+ ret = devm_gpiochip_add_data(dev, gc, data);
+ if (ret) {
+ dev_err(dev, "devm_gpiochip_add_data failed: %d\n", ret);
+ return ret;
+ }
+
+ return ret;
+}
+
#if defined(CONFIG_OF)

#include <linux/of_device.h>
@@ -214,7 +338,7 @@ static int sbsm_probe(struct i2c_client *client,
struct device *dev = &client->dev;
struct power_supply_desc *psy_desc;
struct power_supply_config psy_cfg = {};
- int ret = 0, i, supported_bats;
+ int ret = 0, i;

/* Device listens only at address 0x0a */
if (client->addr != 0x0a)
@@ -235,7 +359,7 @@ static int sbsm_probe(struct i2c_client *client,
ret = sbsm_read_word(client, SBSM_CMD_BATSYSINFO);
if (ret < 0)
return ret;
- supported_bats = le16_to_cpu(ret) & 0xf;
+ data->supported_bats = le16_to_cpu(ret) & 0xf;

data->muxc = i2c_mux_alloc(adapter, dev, SBSM_MAX_BATS, 0,
I2C_MUX_LOCKED, &sbsm_select, NULL);
@@ -247,7 +371,7 @@ static int sbsm_probe(struct i2c_client *client,

/* register muxed i2c channels. One for each supported battery */
for (i = 0; i < SBSM_MAX_BATS; ++i) {
- if ((1 << i) & supported_bats) {
+ if ((1 << i) & data->supported_bats) {
ret = i2c_mux_add_adapter(data->muxc, 0, i + 1, 0);
if (ret) {
dev_err(dev,
@@ -272,6 +396,9 @@ static int sbsm_probe(struct i2c_client *client,
ret = -ENOMEM;
goto err_psy;
}
+ ret = sbsm_gpio_setup(data);
+ if (ret < 0)
+ goto err_psy;

psy_cfg.drv_data = data;
data->psy = devm_power_supply_register(dev, psy_desc, &psy_cfg);
@@ -314,6 +441,7 @@ static struct i2c_driver sbsm_driver = {
},
.probe = sbsm_probe,
.remove = sbsm_remove,
+ .alert = sbsm_alert,
.id_table = sbsm_ids
};
module_i2c_driver(sbsm_driver);
--
1.8.3.1