Revert "All NCT677X chips support RPM registers, so read the RPM directly"

This reverts commit d82b291af288a77835721c2792bbf1478cd25a58.

Sounded like a good idea, but NCT6776 returns an RPM > 0 even
if no fan is connected.

diff --git a/nct6775.c b/nct6775.c
index a0b90e948b7086142b7d147494f897a20fa918e4..8a62992013703c4cafbce9f988b4358cfec7fa0b 100644 (file)
--- a/nct6775.c
+++ b/nct6775.c
@@ -153,6 +153,8 @@ superio_exit(int ioreg)
  * REG_CHIP_ID is at port 0x58
  */
 
+static const u16 NCT6775_REG_FAN_MIN[] = { 0x3b, 0x3c, 0x3d };
+
 /* Voltage min/max registers for nr=7..14 are in bank 5 */
 
 static const u16 NCT6775_REG_IN_MAX[] = {
@@ -249,17 +251,15 @@ static const u16 NCT6775_REG_FAN_STOP_TIME[]
 static const u16 NCT6775_REG_PWM[] = { 0x109, 0x209, 0x309, 0x809, 0x909 };
 static const u16 NCT6775_REG_PWM_READ[] = { 0x01, 0x03, 0x11, 0x13, 0x15 };
 
-static const u16 NCT6775_REG_FAN[] = { 0x656, 0x658, 0x65a, 0x65c, 0x65e };
-
-static const u16 NCT6775_REG_FAN_MIN[] = { 0x3b, 0x3c, 0x3d };
+static const u16 NCT6775_REG_FAN[] = { 0x630, 0x632, 0x634, 0x636, 0x638 };
 
 static const u16 NCT6776_REG_FAN_MIN[] = { 0x63a, 0x63c, 0x63e, 0x640, 0x642};
 
-static const u16 NCT6779_REG_FAN[] = { 0x4c0, 0x4c2, 0x4c4, 0x4c6, 0x4c8 };
-
 static const u16 NCT6779_REG_TOLERANCE_H[]
        = { 0x10c, 0x20c, 0x30c, 0x80c, 0x90c };
 
+static const u16 NCT6779_REG_FAN[] = { 0x4b0, 0x4b2, 0x4b4, 0x4b6, 0x4b8 };
+
 static const u16 NCT6775_REG_TEMP[]
        = { 0x27, 0x150, 0x250, 0x62b, 0x62c, 0x62d };
 static const u16 NCT6779_REG_TEMP[] = { 0x27, 0x150 };
@@ -466,6 +466,18 @@ static unsigned int fan_from_reg13(u16 reg, unsigned int divreg)
        return 1350000U / reg;
 }
 
+static unsigned int fan_from_reg16(u16 reg, unsigned int divreg)
+{
+       if (reg == 0 || reg == 0xffff)
+               return 0;
+
+       /*
+        * Even though the registers are 16 bit wide, the fan divisor
+        * still applies.
+        */
+       return 1350000U / (reg << divreg);
+}
+
 static inline unsigned int
 div_from_reg(u8 reg)
 {
@@ -551,6 +563,7 @@ struct nct6775_data {
 
        const u16 *REG_ALARM;
 
+       unsigned int (*fan_from_reg)(u16 reg, unsigned int divreg);
        unsigned int (*fan_from_reg_min)(u16 reg, unsigned int divreg);
 
        struct mutex update_lock;
@@ -650,7 +663,6 @@ static bool is_word_sized(struct nct6775_data *data, u16 reg)
        case nct6779:
                return reg == 0x150 || reg == 0x153 || reg == 0x155 ||
                  ((reg & 0xfff0) == 0x4b0 && (reg & 0x000f) < 0x09) ||
-                 ((reg & 0xfff0) == 0x4c0 && (reg & 0x000f) < 0x09) ||
                  reg == 0x402 ||
                  reg == 0x63a || reg == 0x63c || reg == 0x63e ||
                  reg == 0x640 || reg == 0x642 ||
@@ -933,24 +945,28 @@ static struct nct6775_data *nct6775_update_device(struct device *dev)
 
                /* Measured fan speeds and limits */
                for (i = 0; i < 5; i++) {
+                       u16 reg;
 
                        if (!(data->has_fan & (1 << i)))
                                continue;
 
-                       data->rpm[i] = nct6775_read_value(data,
-                                                         data->REG_FAN[i]);
+                       reg = nct6775_read_value(data, data->REG_FAN[i]);
+                       data->rpm[i] = data->fan_from_reg(reg,
+                                                         data->fan_div[i]);
 
                        if (data->has_fan_min & (1 << i))
                                data->fan_min[i] = nct6775_read_value(data,
                                           data->REG_FAN_MIN[i]);
 
                        /*
-                        * If we failed to measure the fan speed and the clock
+                        * If we failed to measure the fan speed and clock
                         * divider can be increased, let's try that for next
-                        * time.
+                        * time
                         */
-                       if (data->has_fan_div && data->rpm[i] == 0 &&
-                           data->fan_div[i] < 0x07) {
+                       if (data->has_fan_div
+                           && (reg >= 0xff || (data->kind == nct6775
+                                               && reg == 0x00))
+                           && data->fan_div[i] < 0x07) {
                                dev_dbg(dev,
                                        "Increasing fan%d clock divider from %u to %u\n",
                                        i + 1, div_from_reg(data->fan_div[i]),
@@ -1313,7 +1329,10 @@ store_fan_min(struct device *dev, struct device_attribute *attr,
 
        mutex_lock(&data->update_lock);
        if (!data->has_fan_div) {
-               /* NCT6776F or NCT6779D; we know this is a 13 bit register */
+               /*
+                * Only NCT6776F for now, so we know that this is a 13 bit
+                * register
+                */
                if (!val) {
                        val = 0xff1f;
                } else {
@@ -1383,7 +1402,8 @@ write_div:
        }
 
 write_min:
-       nct6775_write_value(data, data->REG_FAN_MIN[nr], data->fan_min[nr]);
+       nct6775_write_value(data, data->REG_FAN_MIN[nr],
+                             data->fan_min[nr]);
        mutex_unlock(&data->update_lock);
 
        return count;
@@ -3079,6 +3099,7 @@ static int __devinit nct6775_probe(struct platform_device *pdev)
 
                data->ALARM_BITS = NCT6775_ALARM_BITS;
 
+               data->fan_from_reg = fan_from_reg16;
                data->fan_from_reg_min = fan_from_reg8;
 
                data->temp_label = nct6775_temp_label;
@@ -3138,6 +3159,7 @@ static int __devinit nct6775_probe(struct platform_device *pdev)
 
                data->ALARM_BITS = NCT6776_ALARM_BITS;
 
+               data->fan_from_reg = fan_from_reg13;
                data->fan_from_reg_min = fan_from_reg13;
 
                data->temp_label = nct6776_temp_label;
@@ -3196,6 +3218,7 @@ static int __devinit nct6775_probe(struct platform_device *pdev)
 
                data->ALARM_BITS = NCT6779_ALARM_BITS;
 
+               data->fan_from_reg = fan_from_reg13;
                data->fan_from_reg_min = fan_from_reg13;
 
                data->temp_label = nct6779_temp_label;