443 lines
10 KiB
C
443 lines
10 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* Driver for SBS compliant Smart Battery System Managers
|
|
*
|
|
* The device communicates via i2c at address 0x0a and multiplexes access to up
|
|
* to four smart batteries at address 0x0b.
|
|
*
|
|
* Via sysfs interface the online state and charge type are presented.
|
|
*
|
|
* Datasheet SBSM: http://sbs-forum.org/specs/sbsm100b.pdf
|
|
* Datasheet LTC1760: http://cds.linear.com/docs/en/datasheet/1760fb.pdf
|
|
*
|
|
* Karl-Heinz Schneider <karl-heinz@schneider-inet.de>
|
|
*/
|
|
|
|
#include <linux/gpio.h>
|
|
#include <linux/module.h>
|
|
#include <linux/i2c.h>
|
|
#include <linux/i2c-mux.h>
|
|
#include <linux/power_supply.h>
|
|
#include <linux/property.h>
|
|
|
|
#define SBSM_MAX_BATS 4
|
|
#define SBSM_RETRY_CNT 3
|
|
|
|
/* registers addresses */
|
|
#define SBSM_CMD_BATSYSSTATE 0x01
|
|
#define SBSM_CMD_BATSYSSTATECONT 0x02
|
|
#define SBSM_CMD_BATSYSINFO 0x04
|
|
#define SBSM_CMD_LTC 0x3c
|
|
|
|
#define SBSM_MASK_BAT_SUPPORTED GENMASK(3, 0)
|
|
#define SBSM_MASK_CHARGE_BAT GENMASK(7, 4)
|
|
#define SBSM_BIT_AC_PRESENT BIT(0)
|
|
#define SBSM_BIT_TURBO BIT(7)
|
|
|
|
#define SBSM_SMB_BAT_OFFSET 11
|
|
struct sbsm_data {
|
|
struct i2c_client *client;
|
|
struct i2c_mux_core *muxc;
|
|
|
|
struct power_supply *psy;
|
|
|
|
u8 cur_chan; /* currently selected channel */
|
|
struct gpio_chip chip;
|
|
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[] = {
|
|
POWER_SUPPLY_PROP_ONLINE,
|
|
POWER_SUPPLY_PROP_CHARGE_TYPE,
|
|
};
|
|
|
|
static int sbsm_read_word(struct i2c_client *client, u8 address)
|
|
{
|
|
int reg, retries;
|
|
|
|
for (retries = SBSM_RETRY_CNT; retries > 0; retries--) {
|
|
reg = i2c_smbus_read_word_data(client, address);
|
|
if (reg >= 0)
|
|
break;
|
|
}
|
|
|
|
if (reg < 0) {
|
|
dev_err(&client->dev, "failed to read register 0x%02x\n",
|
|
address);
|
|
}
|
|
|
|
return reg;
|
|
}
|
|
|
|
static int sbsm_write_word(struct i2c_client *client, u8 address, u16 word)
|
|
{
|
|
int ret, retries;
|
|
|
|
for (retries = SBSM_RETRY_CNT; retries > 0; retries--) {
|
|
ret = i2c_smbus_write_word_data(client, address, word);
|
|
if (ret >= 0)
|
|
break;
|
|
}
|
|
if (ret < 0)
|
|
dev_err(&client->dev, "failed to write to register 0x%02x\n",
|
|
address);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int sbsm_get_property(struct power_supply *psy,
|
|
enum power_supply_property psp,
|
|
union power_supply_propval *val)
|
|
{
|
|
struct sbsm_data *data = power_supply_get_drvdata(psy);
|
|
int regval = 0;
|
|
|
|
switch (psp) {
|
|
case POWER_SUPPLY_PROP_ONLINE:
|
|
regval = sbsm_read_word(data->client, SBSM_CMD_BATSYSSTATECONT);
|
|
if (regval < 0)
|
|
return regval;
|
|
val->intval = !!(regval & SBSM_BIT_AC_PRESENT);
|
|
break;
|
|
|
|
case POWER_SUPPLY_PROP_CHARGE_TYPE:
|
|
regval = sbsm_read_word(data->client, SBSM_CMD_BATSYSSTATE);
|
|
if (regval < 0)
|
|
return regval;
|
|
|
|
if ((regval & SBSM_MASK_CHARGE_BAT) == 0) {
|
|
val->intval = POWER_SUPPLY_CHARGE_TYPE_NONE;
|
|
return 0;
|
|
}
|
|
val->intval = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
|
|
|
|
if (data->is_ltc1760) {
|
|
/* charge mode fast if turbo is active */
|
|
regval = sbsm_read_word(data->client, SBSM_CMD_LTC);
|
|
if (regval < 0)
|
|
return regval;
|
|
else if (regval & SBSM_BIT_TURBO)
|
|
val->intval = POWER_SUPPLY_CHARGE_TYPE_FAST;
|
|
}
|
|
break;
|
|
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int sbsm_prop_is_writeable(struct power_supply *psy,
|
|
enum power_supply_property psp)
|
|
{
|
|
struct sbsm_data *data = power_supply_get_drvdata(psy);
|
|
|
|
return (psp == POWER_SUPPLY_PROP_CHARGE_TYPE) && data->is_ltc1760;
|
|
}
|
|
|
|
static int sbsm_set_property(struct power_supply *psy,
|
|
enum power_supply_property psp,
|
|
const union power_supply_propval *val)
|
|
{
|
|
struct sbsm_data *data = power_supply_get_drvdata(psy);
|
|
int ret = -EINVAL;
|
|
u16 regval;
|
|
|
|
switch (psp) {
|
|
case POWER_SUPPLY_PROP_CHARGE_TYPE:
|
|
/* write 1 to TURBO if type fast is given */
|
|
if (!data->is_ltc1760)
|
|
break;
|
|
regval = val->intval ==
|
|
POWER_SUPPLY_CHARGE_TYPE_FAST ? SBSM_BIT_TURBO : 0;
|
|
ret = sbsm_write_word(data->client, SBSM_CMD_LTC, regval);
|
|
break;
|
|
|
|
default:
|
|
break;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Switch to battery
|
|
* Parameter chan is directly the content of SMB_BAT* nibble
|
|
*/
|
|
static int sbsm_select(struct i2c_mux_core *muxc, u32 chan)
|
|
{
|
|
struct sbsm_data *data = i2c_mux_priv(muxc);
|
|
struct device *dev = &data->client->dev;
|
|
int ret = 0;
|
|
u16 reg;
|
|
|
|
if (data->cur_chan == chan)
|
|
return ret;
|
|
|
|
/* chan goes from 1 ... 4 */
|
|
reg = BIT(SBSM_SMB_BAT_OFFSET + chan);
|
|
ret = sbsm_write_word(data->client, SBSM_CMD_BATSYSSTATE, reg);
|
|
if (ret)
|
|
dev_err(dev, "Failed to select channel %i\n", chan);
|
|
else
|
|
data->cur_chan = chan;
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int sbsm_gpio_get_value(struct gpio_chip *gc, unsigned int 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 int 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;
|
|
|
|
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);
|
|
|
|
return -EBUSY;
|
|
}
|
|
|
|
static 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, state = 0;
|
|
|
|
ret = sbsm_read_word(sbsm->client, SBSM_CMD_BATSYSSTATE);
|
|
if (ret >= 0) {
|
|
irq_bat = ret ^ sbsm->last_state;
|
|
sbsm->last_state = ret;
|
|
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 & state;
|
|
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,
|
|
NULL, 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;
|
|
int ret;
|
|
|
|
if (!device_property_present(dev, "gpio-controller"))
|
|
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;
|
|
}
|
|
|
|
static const struct power_supply_desc sbsm_default_psy_desc = {
|
|
.type = POWER_SUPPLY_TYPE_MAINS,
|
|
.properties = sbsm_props,
|
|
.num_properties = ARRAY_SIZE(sbsm_props),
|
|
.get_property = &sbsm_get_property,
|
|
.set_property = &sbsm_set_property,
|
|
.property_is_writeable = &sbsm_prop_is_writeable,
|
|
};
|
|
|
|
static int sbsm_probe(struct i2c_client *client,
|
|
const struct i2c_device_id *id)
|
|
{
|
|
struct i2c_adapter *adapter = client->adapter;
|
|
struct sbsm_data *data;
|
|
struct device *dev = &client->dev;
|
|
struct power_supply_desc *psy_desc;
|
|
struct power_supply_config psy_cfg = {};
|
|
int ret = 0, i;
|
|
|
|
/* Device listens only at address 0x0a */
|
|
if (client->addr != 0x0a)
|
|
return -EINVAL;
|
|
|
|
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA))
|
|
return -EPFNOSUPPORT;
|
|
|
|
data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
|
|
if (!data)
|
|
return -ENOMEM;
|
|
|
|
i2c_set_clientdata(client, data);
|
|
|
|
data->client = client;
|
|
data->is_ltc1760 = !!strstr(id->name, "ltc1760");
|
|
|
|
ret = sbsm_read_word(client, SBSM_CMD_BATSYSINFO);
|
|
if (ret < 0)
|
|
return ret;
|
|
data->supported_bats = ret & SBSM_MASK_BAT_SUPPORTED;
|
|
data->muxc = i2c_mux_alloc(adapter, dev, SBSM_MAX_BATS, 0,
|
|
I2C_MUX_LOCKED, &sbsm_select, NULL);
|
|
if (!data->muxc) {
|
|
dev_err(dev, "failed to alloc i2c mux\n");
|
|
ret = -ENOMEM;
|
|
goto err_mux_alloc;
|
|
}
|
|
data->muxc->priv = data;
|
|
|
|
/* register muxed i2c channels. One for each supported battery */
|
|
for (i = 0; i < SBSM_MAX_BATS; ++i) {
|
|
if (data->supported_bats & BIT(i)) {
|
|
ret = i2c_mux_add_adapter(data->muxc, 0, i + 1, 0);
|
|
if (ret)
|
|
break;
|
|
}
|
|
}
|
|
if (ret) {
|
|
dev_err(dev, "failed to register i2c mux channel %d\n", i + 1);
|
|
goto err_mux_register;
|
|
}
|
|
|
|
psy_desc = devm_kmemdup(dev, &sbsm_default_psy_desc,
|
|
sizeof(struct power_supply_desc),
|
|
GFP_KERNEL);
|
|
if (!psy_desc) {
|
|
ret = -ENOMEM;
|
|
goto err_psy;
|
|
}
|
|
|
|
psy_desc->name = devm_kasprintf(dev, GFP_KERNEL, "sbsm-%s",
|
|
dev_name(&client->dev));
|
|
if (!psy_desc->name) {
|
|
ret = -ENOMEM;
|
|
goto err_psy;
|
|
}
|
|
ret = sbsm_gpio_setup(data);
|
|
if (ret < 0)
|
|
goto err_psy;
|
|
|
|
psy_cfg.drv_data = data;
|
|
psy_cfg.of_node = dev->of_node;
|
|
data->psy = devm_power_supply_register(dev, psy_desc, &psy_cfg);
|
|
if (IS_ERR(data->psy)) {
|
|
ret = PTR_ERR(data->psy);
|
|
dev_err(dev, "failed to register power supply %s\n",
|
|
psy_desc->name);
|
|
goto err_psy;
|
|
}
|
|
|
|
return 0;
|
|
|
|
err_psy:
|
|
err_mux_register:
|
|
i2c_mux_del_adapters(data->muxc);
|
|
|
|
err_mux_alloc:
|
|
return ret;
|
|
}
|
|
|
|
static int sbsm_remove(struct i2c_client *client)
|
|
{
|
|
struct sbsm_data *data = i2c_get_clientdata(client);
|
|
|
|
i2c_mux_del_adapters(data->muxc);
|
|
return 0;
|
|
}
|
|
|
|
static const struct i2c_device_id sbsm_ids[] = {
|
|
{ "sbs-manager", 0 },
|
|
{ "ltc1760", 0 },
|
|
{ }
|
|
};
|
|
MODULE_DEVICE_TABLE(i2c, sbsm_ids);
|
|
|
|
#ifdef CONFIG_OF
|
|
static const struct of_device_id sbsm_dt_ids[] = {
|
|
{ .compatible = "sbs,sbs-manager" },
|
|
{ .compatible = "lltc,ltc1760" },
|
|
{ }
|
|
};
|
|
MODULE_DEVICE_TABLE(of, sbsm_dt_ids);
|
|
#endif
|
|
|
|
static struct i2c_driver sbsm_driver = {
|
|
.driver = {
|
|
.name = "sbsm",
|
|
.of_match_table = of_match_ptr(sbsm_dt_ids),
|
|
},
|
|
.probe = sbsm_probe,
|
|
.remove = sbsm_remove,
|
|
.alert = sbsm_alert,
|
|
.id_table = sbsm_ids
|
|
};
|
|
module_i2c_driver(sbsm_driver);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("Karl-Heinz Schneider <karl-heinz@schneider-inet.de>");
|
|
MODULE_DESCRIPTION("SBSM Smart Battery System Manager");
|