Read only one of the GPIO pins as an analog voltage. The ADC can be
switched to a different GPIO pin at runtime, but this is not supported.
Signed-off-by: Ira W. Snyder <iws@xxxxxxxxxxxxxxxx>
---
Documentation/hwmon/ltc4245 | 4 +--
drivers/hwmon/ltc4245.c | 71 ++++---------------------------------------
2 files changed, 7 insertions(+), 68 deletions(-)
diff --git a/Documentation/hwmon/ltc4245 b/Documentation/hwmon/ltc4245
index 02838a4..86b5880 100644
--- a/Documentation/hwmon/ltc4245
+++ b/Documentation/hwmon/ltc4245
@@ -72,9 +72,7 @@ in6_min_alarm 5v output undervoltage alarm
in7_min_alarm 3v output undervoltage alarm
in8_min_alarm Vee (-12v) output undervoltage alarm
-in9_input GPIO #1 voltage data
-in10_input GPIO #2 voltage data
-in11_input GPIO #3 voltage data
+in9_input GPIO voltage data
power1_input 12v power usage (mW)
power2_input 5v power usage (mW)
diff --git a/drivers/hwmon/ltc4245.c b/drivers/hwmon/ltc4245.c
index 1efa554..4926f3f 100644
--- a/drivers/hwmon/ltc4245.c
+++ b/drivers/hwmon/ltc4245.c
@@ -45,9 +45,7 @@ enum ltc4245_cmd {
LTC4245_VEEIN = 0x19,
LTC4245_VEESENSE = 0x1a,
LTC4245_VEEOUT = 0x1b,
- LTC4245_GPIOADC1 = 0x1c,
- LTC4245_GPIOADC2 = 0x1d,
- LTC4245_GPIOADC3 = 0x1e,
+ LTC4245_GPIOADC = 0x1c,
};
struct ltc4245_data {
@@ -61,7 +59,7 @@ struct ltc4245_data {
u8 cregs[0x08];
/* Voltage registers */
- u8 vregs[0x0f];
+ u8 vregs[0x0d];
};
static struct ltc4245_data *ltc4245_update_device(struct device *dev)
@@ -87,8 +85,8 @@ static struct ltc4245_data *ltc4245_update_device(struct device *dev)
data->cregs[i] = val;
}
- /* Read non-GPIO voltage registers -- 0x10 to 0x1b */
- for (i = 0; i < ARRAY_SIZE(data->vregs) - 3; i++) {
+ /* Read voltage registers -- 0x10 to 0x1c */
+ for (i = 0; i < ARRAY_SIZE(data->vregs); i++) {
val = i2c_smbus_read_byte_data(client, i + 0x10);
if (unlikely(val < 0))
data->vregs[i] = 0;
@@ -96,59 +94,6 @@ static struct ltc4245_data *ltc4245_update_device(struct device *dev)
data->vregs[i] = val;
}
- /*
- * On the LTC4245, the GPIO registers act stupidly. Changing
- * the MUX to read from any GPIO puts the value into all three
- * GPIO registers. To avoid this, we cache a copy of the
- * current GPIO state, and advance the MUX to the next state.
- *
- * This will mean that readings can be up to 3 cycles old,
- * which shouldn't be a problem. The hwmon interface is not
- * expected to be fast.
- */
- gpio = data->cregs[LTC4245_GPIO] & 0xC0;
- switch (gpio) {
- default:
- /*
- * this is just to keep the compiler happy, we
- * handle every possible state of the top two
- * bits in this register
- */
- case 0x00:
- case 0x40:
- addr = LTC4245_GPIOADC1;
- nextgpio = (data->cregs[LTC4245_GPIO] & 0x3f) | 0x80;
- break;
- case 0x80:
- addr = LTC4245_GPIOADC2;
- nextgpio = (data->cregs[LTC4245_GPIO] & 0x3f) | 0xc0;
- break;
- case 0xc0:
- addr = LTC4245_GPIOADC3;
- nextgpio = (data->cregs[LTC4245_GPIO] & 0x3f) | 0x40;
- break;
- }
-
- /* Read the current GPIO state, cache the value */
- val = i2c_smbus_read_byte_data(client, addr);
- if (unlikely(val < 0))
- data->vregs[addr - 0x10] = 0;
- else
- data->vregs[addr - 0x10] = val;
-
- /*
- * Set the GPIO MUX register to read the next GPIO
- *
- * According to the datasheet, the ADC must be stopped before
- * writing to the control register, so we disable it, and then
- * put it back to its earlier state
- */
- ctl = data->cregs[LTC4245_CONTROL];
- i2c_smbus_write_byte_data(client, LTC4245_CONTROL, ctl | 0x80);
- i2c_smbus_write_byte_data(client, LTC4245_GPIO, nextgpio);
- i2c_smbus_write_byte_data(client, LTC4245_CONTROL, ctl);
- data->cregs[LTC4245_GPIO] = nextgpio;
-
data->last_updated = jiffies;
data->valid = 1;
}
@@ -182,9 +127,7 @@ static int ltc4245_get_voltage(struct device *dev, u8 reg)
case LTC4245_VEEOUT:
voltage = regval * -55;
break;
- case LTC4245_GPIOADC1:
- case LTC4245_GPIOADC2:
- case LTC4245_GPIOADC3:
+ case LTC4245_GPIOADC:
voltage = regval * 10;
break;
default:
@@ -351,9 +294,7 @@ LTC4245_ALARM(in7_min_alarm, (1 << 2), LTC4245_FAULT2);
LTC4245_ALARM(in8_min_alarm, (1 << 3), LTC4245_FAULT2);
/* GPIO voltages */
-LTC4245_VOLTAGE(in9_input, LTC4245_GPIOADC1);
-LTC4245_VOLTAGE(in10_input, LTC4245_GPIOADC2);
-LTC4245_VOLTAGE(in11_input, LTC4245_GPIOADC3);
+LTC4245_VOLTAGE(in9_input, LTC4245_GPIOADC);
/* Power Consumption (virtual) */
LTC4245_POWER(power1_input, LTC4245_12VSENSE);
--
1.5.4.3
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