power: supply: ltc2941-battery-gauge: Prepare for LTC2942 and LTC2944

In order to support LTC2942 which has temperature registers
at different offsets than LTC2943 use following register naming
scheme (prefixes):
- LTC294X_ common registers
- LTC2942_ chips specific registers
- LTC2943_ specific registers

LTC2944 is compatible with LTC2943 but uses different constants
to compute voltage and current, so replace num_regs misused
for device indentification with real device id to discriminate
between those two.

There are no functional changes.

Signed-off-by: Ladislav Michl <ladis@linux-mips.org>
Acked-by: Dragos Bogdan <dragos.bogdan@analog.com>
Tested-by: Dragos Bogdan <dragos.bogdan@analog.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>

diff --git a/drivers/power/supply/ltc2941-battery-gauge.c b/drivers/power/supply/ltc2941-battery-gauge.c
index 7efb908..b0de448 100644 (file)
--- a/drivers/power/supply/ltc2941-battery-gauge.c
+++ b/drivers/power/supply/ltc2941-battery-gauge.c
@@ -34,16 +34,19 @@ enum ltc294x_reg {
        LTC294X_REG_CONTROL             = 0x01,
        LTC294X_REG_ACC_CHARGE_MSB      = 0x02,
        LTC294X_REG_ACC_CHARGE_LSB      = 0x03,
-       LTC294X_REG_THRESH_HIGH_MSB     = 0x04,
-       LTC294X_REG_THRESH_HIGH_LSB     = 0x05,
-       LTC294X_REG_THRESH_LOW_MSB      = 0x06,
-       LTC294X_REG_THRESH_LOW_LSB      = 0x07,
-       LTC294X_REG_VOLTAGE_MSB = 0x08,
-       LTC294X_REG_VOLTAGE_LSB = 0x09,
-       LTC294X_REG_CURRENT_MSB = 0x0E,
-       LTC294X_REG_CURRENT_LSB = 0x0F,
-       LTC294X_REG_TEMPERATURE_MSB     = 0x14,
-       LTC294X_REG_TEMPERATURE_LSB     = 0x15,
+       LTC294X_REG_VOLTAGE_MSB         = 0x08,
+       LTC294X_REG_VOLTAGE_LSB         = 0x09,
+       LTC2942_REG_TEMPERATURE_MSB     = 0x0C,
+       LTC2942_REG_TEMPERATURE_LSB     = 0x0D,
+       LTC2943_REG_CURRENT_MSB         = 0x0E,
+       LTC2943_REG_CURRENT_LSB         = 0x0F,
+       LTC2943_REG_TEMPERATURE_MSB     = 0x14,
+       LTC2943_REG_TEMPERATURE_LSB     = 0x15,
+};
+
+enum ltc294x_id {
+       LTC2941_ID,
+       LTC2943_ID,
 };
 
 #define LTC2943_REG_CONTROL_MODE_MASK (BIT(7) | BIT(6))
@@ -54,15 +57,12 @@ enum ltc294x_reg {
        ((x << 3) & LTC294X_REG_CONTROL_PRESCALER_MASK)
 #define LTC294X_REG_CONTROL_ALCC_CONFIG_DISABLED       0
 
-#define LTC2941_NUM_REGS       0x08
-#define LTC2943_NUM_REGS       0x18
-
 struct ltc294x_info {
        struct i2c_client *client;      /* I2C Client pointer */
        struct power_supply *supply;    /* Supply pointer */
        struct power_supply_desc supply_desc;   /* Supply description */
        struct delayed_work work;       /* Work scheduler */
-       unsigned long num_regs; /* Number of registers (chip type) */
+       enum ltc294x_id id;             /* Chip type */
        int charge;     /* Last charge register content */
        int r_sense;    /* mOhm */
        int Qlsb;       /* nAh */
@@ -146,7 +146,7 @@ static int ltc294x_reset(const struct ltc294x_info *info, int prescaler_exp)
        control = LTC294X_REG_CONTROL_PRESCALER_SET(prescaler_exp) |
                                LTC294X_REG_CONTROL_ALCC_CONFIG_DISABLED;
        /* Put the 2943 into "monitor" mode, so it measures every 10 sec */
-       if (info->num_regs == LTC2943_NUM_REGS)
+       if (info->id == LTC2941_ID)
                control |= LTC2943_REG_CONTROL_MODE_SCAN;
 
        if (value != control) {
@@ -263,7 +263,7 @@ static int ltc294x_get_current(const struct ltc294x_info *info, int *val)
        s32 value;
 
        ret = ltc294x_read_regs(info->client,
-               LTC294X_REG_CURRENT_MSB, &datar[0], 2);
+               LTC2943_REG_CURRENT_MSB, &datar[0], 2);
        value = (datar[0] << 8) | datar[1];
        value -= 0x7FFF;
        /* Value is in range -32k..+32k, r_sense is usually 10..50 mOhm,
@@ -280,7 +280,7 @@ static int ltc294x_get_temperature(const struct ltc294x_info *info, int *val)
        u32 value;
 
        ret = ltc294x_read_regs(info->client,
-               LTC294X_REG_TEMPERATURE_MSB, &datar[0], 2);
+               LTC2943_REG_TEMPERATURE_MSB, &datar[0], 2);
        value = (datar[0] << 8) | datar[1];
        /* Full-scale is 510 Kelvin, convert to centidegrees  */
        *val = (((51000 * value) / 0xFFFF) - 27215);
@@ -357,8 +357,8 @@ static enum power_supply_property ltc294x_properties[] = {
        POWER_SUPPLY_PROP_CHARGE_COUNTER,
        POWER_SUPPLY_PROP_CHARGE_NOW,
        POWER_SUPPLY_PROP_VOLTAGE_NOW,
-       POWER_SUPPLY_PROP_CURRENT_NOW,
        POWER_SUPPLY_PROP_TEMP,
+       POWER_SUPPLY_PROP_CURRENT_NOW,
 };
 
 static int ltc294x_i2c_remove(struct i2c_client *client)
@@ -388,7 +388,7 @@ static int ltc294x_i2c_probe(struct i2c_client *client,
 
        np = of_node_get(client->dev.of_node);
 
-       info->num_regs = (unsigned long)of_device_get_match_data(&client->dev);
+       info->id = (enum ltc294x_id)of_device_get_match_data(&client->dev);
        info->supply_desc.name = np->name;
 
        /* r_sense can be negative, when sense+ is connected to the battery
@@ -409,7 +409,7 @@ static int ltc294x_i2c_probe(struct i2c_client *client,
                prescaler_exp = LTC2941_MAX_PRESCALER_EXP;
        }
 
-       if (info->num_regs == LTC2943_NUM_REGS) {
+       if (info->id == LTC2943_ID) {
                if (prescaler_exp > LTC2943_MAX_PRESCALER_EXP)
                        prescaler_exp = LTC2943_MAX_PRESCALER_EXP;
                info->Qlsb = ((340 * 50000) / r_sense) /
@@ -424,18 +424,17 @@ static int ltc294x_i2c_probe(struct i2c_client *client,
        info->client = client;
        info->supply_desc.type = POWER_SUPPLY_TYPE_BATTERY;
        info->supply_desc.properties = ltc294x_properties;
-       if (info->num_regs >= LTC294X_REG_TEMPERATURE_LSB)
+       switch (info->id) {
+       case LTC2943_ID:
                info->supply_desc.num_properties =
                        ARRAY_SIZE(ltc294x_properties);
-       else if (info->num_regs >= LTC294X_REG_CURRENT_LSB)
-               info->supply_desc.num_properties =
-                       ARRAY_SIZE(ltc294x_properties) - 1;
-       else if (info->num_regs >= LTC294X_REG_VOLTAGE_LSB)
-               info->supply_desc.num_properties =
-                       ARRAY_SIZE(ltc294x_properties) - 2;
-       else
+               break;
+       case LTC2941_ID:
+       default:
                info->supply_desc.num_properties =
                        ARRAY_SIZE(ltc294x_properties) - 3;
+               break;
+       }
        info->supply_desc.get_property = ltc294x_get_property;
        info->supply_desc.set_property = ltc294x_set_property;
        info->supply_desc.property_is_writeable = ltc294x_property_is_writeable;
@@ -492,8 +491,8 @@ static SIMPLE_DEV_PM_OPS(ltc294x_pm_ops, ltc294x_suspend, ltc294x_resume);
 
 
 static const struct i2c_device_id ltc294x_i2c_id[] = {
-       {"ltc2941", LTC2941_NUM_REGS},
-       {"ltc2943", LTC2943_NUM_REGS},
+       { "ltc2941", LTC2941_ID, },
+       { "ltc2943", LTC2943_ID, },
        { },
 };
 MODULE_DEVICE_TABLE(i2c, ltc294x_i2c_id);
@@ -501,11 +500,11 @@ MODULE_DEVICE_TABLE(i2c, ltc294x_i2c_id);
 static const struct of_device_id ltc294x_i2c_of_match[] = {
        {
                .compatible = "lltc,ltc2941",
-               .data = (void *)LTC2941_NUM_REGS
+               .data = (void *)LTC2941_ID,
        },
        {
                .compatible = "lltc,ltc2943",
-               .data = (void *)LTC2943_NUM_REGS
+               .data = (void *)LTC2943_ID,
        },
        { },
 };