Initial support for access and modification of the non-volatile regions
of the bq27425 fuel gauge DesignEnergy, DesignCapacity, and
TerminateVoltage settings.
This is intended for fine tuning the fuel gauge state machine for the
respective battery specifications.
Cc: Sebastian Reichel <sre@xxxxxxxxxx>
Signed-off-by: Matt Ranostay <matt@ranostay.consulting>
---
drivers/power/supply/bq27xxx_battery_i2c.c | 335 +++++++++++++++++++++++++++++
include/linux/power/bq27xxx_battery.h | 4 +
2 files changed, 339 insertions(+)
diff --git a/drivers/power/supply/bq27xxx_battery_i2c.c b/drivers/power/supply/bq27xxx_battery_i2c.c
index 27143230839a..8ec278e15ab6 100644
--- a/drivers/power/supply/bq27xxx_battery_i2c.c
+++ b/drivers/power/supply/bq27xxx_battery_i2c.c
@@ -14,9 +14,11 @@
* GNU General Public License for more details.
*/
+#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/module.h>
+#include <linux/of.h>
#include <asm/unaligned.h>
#include <linux/power/bq27xxx_battery.h>
@@ -24,6 +26,48 @@
static DEFINE_IDR(battery_id);
static DEFINE_MUTEX(battery_mutex);
+#define BQ27XXX_TERM_V_MIN 2800
+#define BQ27XXX_TERM_V_MAX 3700
+
+#define BQ27XXX_REG_CTRL 0
+
+#define BQ27XXX_BLOCK_DATA_CLASS 0x3E
+#define BQ27XXX_DATA_BLOCK 0x3F
+#define BQ27XXX_BLOCK_DATA 0x40
+#define BQ27XXX_BLOCK_DATA_CHECKSUM 0x60
+#define BQ27XXX_BLOCK_DATA_CONTROL 0x61
+#define BQ27XXX_SET_CFGUPDATE 0x13
+#define BQ27XXX_SOFT_RESET 0x42
+
+enum bq27xxx_dm_subclass_index {
+ BQ27XXX_DM_DESIGN_CAP = 0,
+ BQ27XXX_DM_DESIGN_ENERGY,
+ BQ27XXX_DM_TERMINATE_VOLTAGE,
+ BQ27XXX_NUM_IDX,
+};
+
+struct bq27xxx_dm_regs {
+ unsigned int subclass_id;
+ unsigned int offset;
+ char *name;
+};
+
+#define BQ27XXX_GAS_GAUGING_STATE_SUBCLASS 82
+
+static struct bq27xxx_dm_regs bq27425_dm_subclass_regs[] = {
+ { BQ27XXX_GAS_GAUGING_STATE_SUBCLASS, 12, "design-capacity" },
+ { BQ27XXX_GAS_GAUGING_STATE_SUBCLASS, 14, "design-energy" },
+ { BQ27XXX_GAS_GAUGING_STATE_SUBCLASS, 18, "terminate-voltage" },
+};
+
+static struct bq27xxx_dm_regs *bq27xxx_dm_subclass_regs[] = {
+ [BQ27425] = bq27425_dm_subclass_regs,
+};
+
+static unsigned int bq27xxx_unseal_keys[] = {
+ [BQ27425] = 0x04143672,
+};
+
static irqreturn_t bq27xxx_battery_irq_handler_thread(int irq, void *data)
{
struct bq27xxx_device_info *di = data;
@@ -68,6 +112,289 @@ static int bq27xxx_battery_i2c_read(struct bq27xxx_device_info *di, u8 reg,
return ret;
}
+static int bq27xxx_battery_i2c_write(struct bq27xxx_device_info *di, u8 reg,
+ int value, bool single)
+{
+ struct i2c_client *client = to_i2c_client(di->dev);
+ struct i2c_msg msg;
+ unsigned char data[4];
+
+ if (!client->adapter)
+ return -ENODEV;
+
+ data[0] = reg;
+ if (single) {
+ data[1] = (unsigned char) value;
+ msg.len = 2;
+ } else {
+ put_unaligned_le16(value, &data[1]);
+ msg.len = 3;
+ }
+
+ msg.buf = data;
+ msg.addr = client->addr;
+ msg.flags = 0;
+
+ return i2c_transfer(client->adapter, &msg, 1) == 1 ? 0 : -EINVAL;
+}
+
+static int bq27xxx_battery_i2c_bulk_read(struct bq27xxx_device_info *di, u8 reg,
+ u8 *data, int len)
+{
+ struct i2c_client *client = to_i2c_client(di->dev);
+
+ if (!client->adapter)
+ return -ENODEV;
+
+ return i2c_smbus_read_i2c_block_data(client, reg, len, data);
+}
+
+static int bq27xxx_battery_i2c_bulk_write(struct bq27xxx_device_info *di,
+ u8 reg, u8 *data, int len)
+{
+ struct i2c_client *client = to_i2c_client(di->dev);
+ struct i2c_msg msg;
+ u8 buf[33];
+
+ if (!client->adapter)
+ return -ENODEV;
+
+ buf[0] = reg;
+ memcpy(&buf[1], data, len);
+
+ msg.buf = buf;
+ msg.addr = client->addr;
+ msg.flags = 0;
+ msg.len = len + 1;
+
+ return i2c_transfer(client->adapter, &msg, 1) == 1 ? 0 : -EINVAL;
+}
+
+static int bq27xxx_battery_i2c_set_seal_state(struct bq27xxx_device_info *di,
+ bool state)
+{
+ unsigned int key = bq27xxx_unseal_keys[di->chip];
+ int ret;
+
+ if (state)
+ return di->bus.write(di, BQ27XXX_REG_CTRL, 0x20, false);
+
+ ret = di->bus.write(di, BQ27XXX_REG_CTRL, (key >> 16) & 0xffff, false);
+ if (ret < 0)
+ return ret;
+
+ return di->bus.write(di, BQ27XXX_REG_CTRL, key & 0xffff, false);
+}
+
+static int bq27xxx_battery_i2c_read_dm_block(struct bq27xxx_device_info *di,
+ int subclass)
+{
+ int ret = di->bus.write(di, BQ27XXX_REG_CTRL, 0, false);
+
+ if (ret < 0)
+ return ret;
+
+ ret = di->bus.write(di, BQ27XXX_BLOCK_DATA_CONTROL, 0, true);
+ if (ret < 0)
+ return ret;
+
+ ret = di->bus.write(di, BQ27XXX_BLOCK_DATA_CLASS, subclass, true);
+ if (ret < 0)
+ return ret;
+
+ ret = di->bus.write(di, BQ27XXX_DATA_BLOCK, 0, true);
+ if (ret < 0)
+ return ret;
+
+ usleep_range(1000, 1500);
+
+ return di->bus.read_bulk(di, BQ27XXX_BLOCK_DATA,
+ (u8 *) &di->buffer, sizeof(di->buffer));
+}
+
+static int bq27xxx_battery_i2c_print_config(struct bq27xxx_device_info *di)
+{
+ struct bq27xxx_dm_regs *reg = bq27xxx_dm_subclass_regs[di->chip];
+ int ret, i;
+
+ ret = bq27xxx_battery_i2c_read_dm_block(di,
+ BQ27XXX_GAS_GAUGING_STATE_SUBCLASS);
+ if (ret < 0)
+ return ret;
+
+ for (i = 0; i < BQ27XXX_NUM_IDX; i++) {
+ int val;
+
+ if (reg->subclass_id != BQ27XXX_GAS_GAUGING_STATE_SUBCLASS)
+ continue;
+
+ val = be16_to_cpup((u16 *) &di->buffer[reg->offset]);
+
+ dev_info(di->dev, "settings for %s set at %d\n", reg->name, val);
+
+ reg++;
+ }
+
+ return 0;
+}
+
+static bool bq27xxx_battery_update_dm_setting(struct bq27xxx_device_info *di,
+ unsigned int reg, unsigned int val)
+{
+ struct bq27xxx_dm_regs *dm_reg = &bq27xxx_dm_subclass_regs[di->chip][reg];
+ u16 *prev = (u16 *) &di->buffer[dm_reg->offset];
+
+ if (be16_to_cpup(prev) == val)
+ return false;
+
+ *prev = cpu_to_be16(val);
+
+ return true;
+}
+
+static u8 bq27xxx_battery_checksum(struct bq27xxx_device_info *di)
+{
+ u8 *data = (u8 *) &di->buffer;
+ u16 sum = 0;
+ int i;
+
+ for (i = 0; i < sizeof(di->buffer); i++) {
+ sum += data[i];
+ sum &= 0xff;
+ }
+
+ return 0xff - sum;
+}
+
+static int bq27xxx_battery_i2c_write_nvram(struct bq27xxx_device_info *di,
+ unsigned int subclass)
+{
+ int ret;
+
+ ret = di->bus.write(di, BQ27XXX_REG_CTRL, BQ27XXX_SET_CFGUPDATE, false);
+ if (ret)
+ return ret;
+
+ ret = di->bus.write(di, BQ27XXX_BLOCK_DATA_CONTROL, 0, true);
+ if (ret)
+ return ret;
+
+ ret = di->bus.write(di, BQ27XXX_BLOCK_DATA_CLASS, subclass, true);
+ if (ret)
+ return ret;
+
+ ret = di->bus.write(di, BQ27XXX_DATA_BLOCK, 0, true);
+ if (ret)
+ return ret;
+
+ ret = di->bus.write_bulk(di, BQ27XXX_BLOCK_DATA,
+ (u8 *) &di->buffer, sizeof(di->buffer));
+ if (ret < 0)
+ return ret;
+
+ usleep_range(1000, 1500);
+
+ di->bus.write(di, BQ27XXX_BLOCK_DATA_CHECKSUM,
+ bq27xxx_battery_checksum(di), true);
+
+ usleep_range(1000, 1500);
+
+ di->bus.write(di, BQ27XXX_REG_CTRL, BQ27XXX_SOFT_RESET, false);
+
+ return 0;
+}
+
+static int bq27xxx_battery_i2c_set_config(struct bq27xxx_device_info *di,
+ unsigned int cap, unsigned int energy,
+ unsigned int voltage)
+{
+ int ret = bq27xxx_battery_i2c_read_dm_block(di,
+ BQ27XXX_GAS_GAUGING_STATE_SUBCLASS);
+
+ if (ret < 0)
+ return ret;
+
+ ret = bq27xxx_battery_update_dm_setting(di, BQ27XXX_DM_DESIGN_CAP, cap);
+ ret |= bq27xxx_battery_update_dm_setting(di, BQ27XXX_DM_DESIGN_ENERGY,
+ energy);
+ ret |= bq27xxx_battery_update_dm_setting(di, BQ27XXX_DM_TERMINATE_VOLTAGE,
+ voltage);
+
+ if (ret) {
+ dev_info(di->dev, "updating NVM settings\n");
+ return bq27xxx_battery_i2c_write_nvram(di,
+ BQ27XXX_GAS_GAUGING_STATE_SUBCLASS);
+ }
+
+ return 0;
+}
+
+static int bq27xxx_battery_i2c_parse_dt(struct bq27xxx_device_info *di)
+{
+ struct device_node *np = di->dev->of_node;
+ int cap, energy, voltage = -EINVAL;
+ int ret = 0;
+
+ /* no settings to be set for this chipset so abort */
+ if (!bq27xxx_dm_subclass_regs[di->chip])
+ return 0;
+
+ bq27xxx_battery_i2c_set_seal_state(di, false);
+
+ if (np) {
+ ret = of_property_read_u32(np, "ti,design-microamp-hours", &cap);
+ if (ret < 0 || cap > 0x7fff) {
+ if (!ret)
+ dev_err(di->dev,
+ "invalid ti,design-microamp-hours %d\n",
+ cap);
+ cap = -EINVAL;
+ }
+
+ ret = of_property_read_u32(np, "ti,design-microwatt-hours",
+ &energy);
+ if (ret < 0 || energy > 0x7fff) {
+ if (!ret)
+ dev_err(di->dev,
+ "invalid ti,design-microwatt-hours %d\n",
+ energy);
+ energy = -EINVAL;
+ }
+
+ ret = of_property_read_u32(np, "ti,terminate-microvolt", &voltage);
+ if (ret < 0 || voltage < BQ27XXX_TERM_V_MIN
+ || voltage > BQ27XXX_TERM_V_MAX) {
+ if (!ret)
+ dev_err(di->dev,
+ "invalid ti,terminate-microvolt %d\n",
+ voltage);
+ voltage = -EINVAL;
+ }
+
+ /* assume that we want the defaults */
+ if (cap < 0 && energy < 0 && voltage < 0) {
+ ret = 0;
+ goto out;
+ }
+
+ /* we need all three settings for safety reasons */
+ if (cap < 0 || energy < 0 || voltage < 0) {
+ dev_err(di->dev,
+ "missing or invalid devicetree values; NVM not updated\n");
+ ret = -EINVAL;
+ goto out;
+ }
+
+ ret = bq27xxx_battery_i2c_set_config(di, cap, energy, voltage);
+ }
+
+out:
+ bq27xxx_battery_i2c_print_config(di);
+ bq27xxx_battery_i2c_set_seal_state(di, true);
+
+ return ret;
+}
+
static int bq27xxx_battery_i2c_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
@@ -95,7 +422,15 @@ static int bq27xxx_battery_i2c_probe(struct i2c_client *client,
di->dev = &client->dev;
di->chip = id->driver_data;
di->name = name;
+
di->bus.read = bq27xxx_battery_i2c_read;
+ di->bus.write = bq27xxx_battery_i2c_write;
+ di->bus.read_bulk = bq27xxx_battery_i2c_bulk_read;
+ di->bus.write_bulk = bq27xxx_battery_i2c_bulk_write;
+
+ ret = bq27xxx_battery_i2c_parse_dt(di);
+ if (ret)
+ goto err_failed;
ret = bq27xxx_battery_setup(di);
if (ret)
diff --git a/include/linux/power/bq27xxx_battery.h b/include/linux/power/bq27xxx_battery.h
index 14ecac158150..22b4cfc3acab 100644
--- a/include/linux/power/bq27xxx_battery.h
+++ b/include/linux/power/bq27xxx_battery.h
@@ -33,6 +33,9 @@ struct bq27xxx_platform_data {
struct bq27xxx_device_info;
struct bq27xxx_access_methods {
int (*read)(struct bq27xxx_device_info *di, u8 reg, bool single);
+ int (*write)(struct bq27xxx_device_info *di, u8 reg, int value, bool single);
+ int (*read_bulk)(struct bq27xxx_device_info *di, u8 reg, u8 *data, int len);
+ int (*write_bulk)(struct bq27xxx_device_info *di, u8 reg, u8 *data, int len);
};
struct bq27xxx_reg_cache {
@@ -62,6 +65,7 @@ struct bq27xxx_device_info {
struct power_supply *bat;
struct list_head list;
struct mutex lock;
+ u8 buffer[32];
u8 *regs;
};
--
2.10.2
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