These kind of registers need a special sequence to be accessed.
Signed-off-by: Juergen Borleis <[email protected]>
---
drivers/power/bq27x00_battery.c | 42 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 42 insertions(+)
diff --git a/drivers/power/bq27x00_battery.c b/drivers/power/bq27x00_battery.c
index f3de29e..58644de 100644
--- a/drivers/power/bq27x00_battery.c
+++ b/drivers/power/bq27x00_battery.c
@@ -70,6 +70,9 @@
#define BQ27500_FLAG_FC BIT(9)
#define BQ27500_FLAG_OTC BIT(15)
+/* bq27425 control commands */
+#define BQ27425_CONTROL 0x00
+
/* bq27425 register addresses are same as bq27x00 addresses minus 4 */
#define BQ27425_REG_OFFSET 0x04
#define BQ27425_REG_SOC 0x20 /* Register address plus
offset */
@@ -80,6 +83,7 @@
struct bq27x00_device_info;
struct bq27x00_access_methods {
int (*read)(struct bq27x00_device_info *di, u8 reg, bool single);
+ int (*reads)(struct bq27x00_device_info *di, u16 creg);
};
enum bq27x00_chip { BQ27000, BQ27500, BQ27425};
@@ -782,6 +786,42 @@ static int bq27x00_read_i2c(struct bq27x00_device_info
*di, u8 reg, bool single)
return ret;
}
+static int bq27425_read_i2c_control(struct bq27x00_device_info *di, u16 creg)
+{
+ struct i2c_client *client = to_i2c_client(di->dev);
+ struct i2c_msg msg[2];
+ unsigned char cntl[3];
+ unsigned char data[2];
+ int ret;
+
+ if (!client->adapter)
+ return -ENODEV;
+
+ msg[0].addr = client->addr;
+ msg[0].flags = 0;
+ cntl[0] = BQ27425_CONTROL; /* CNTL command */
+ put_unaligned_le16(creg, &cntl[1]); /* CNTL DATA */
+ msg[0].buf = cntl;
+ msg[0].len = sizeof(cntl);
+ msg[1].addr = client->addr;
+ msg[1].flags = I2C_M_RD;
+ msg[1].buf = data;
+ msg[1].len = sizeof(data);
+
+ ret = i2c_transfer(client->adapter, msg, 1);
+ if (ret < 0)
+ return ret;
+
+ udelay(100); /* at least 66 µs pause */
+
+ msg[0].len = 1; /* only the command again, not the subcommand */
+
+ ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
+ if (ret < 0)
+ return ret;
+
+ return get_unaligned_le16(data);
+}
static int bq27x00_battery_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
@@ -816,6 +856,8 @@ static int bq27x00_battery_probe(struct i2c_client *client,
di->chip = id->driver_data;
di->bat.name = name;
di->bus.read = &bq27x00_read_i2c;
+ if (di->chip == BQ27425)
+ di->bus.reads = bq27425_read_i2c_control;
retval = bq27x00_powersupply_init(di);
if (retval)
--
2.0.0.rc2
--
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