+static unsigned int armada_mc_to_reg_temp(struct armada_thermal_data *data,
+ unsigned int temp_mc)
+{
+ s64 b = data->coef_b;
+ s64 m = data->coef_m;
+ s64 div = data->coef_div;
+ unsigned int sample;
+
+ if (data->inverted)
+ sample = div_s64(((temp_mc * div) + b), m);
+ else
+ sample = div_s64((b - (temp_mc * div)), m);
+
+ return sample & data->temp_mask;
+}
+
+/*
+ * The documentation states:
+ * high/low watermark = threshold +/- 0.4761 * 2^(hysteresis + 2)
+ * which is the mathematical derivation for:
+ * 0x0 <=> 1.9°C, 0x1 <=> 3.8°C, 0x2 <=> 7.6°C, 0x3 <=> 15.2°C
+ */
+static unsigned int hyst_levels_mc[] = {1900, 3800, 7600, 15200};
+
+static unsigned int armada_mc_to_reg_hyst(struct armada_thermal_data *data,
+ unsigned int hyst_mc)
+{
+ int i;
+
+ /*
+ * We will always take the smallest possible hysteresis to avoid risking
+ * the hardware integrity by enlarging the threshold by +8°C in the
+ * worst case.
+ */
+ for (i = ARRAY_SIZE(hyst_levels_mc) - 1; i > 0; i--)
+ if (hyst_mc >= hyst_levels_mc[i])
+ break;
+
+ return i & data->hyst_mask;
+}
+
+static void armada_set_overheat_thresholds(struct armada_thermal_priv *priv,
+ int thresh_mc, int hyst_mc)
+{
+ struct armada_thermal_data *data = priv->data;
+ unsigned int threshold = armada_mc_to_reg_temp(data, thresh_mc);
+ unsigned int hysteresis = armada_mc_to_reg_hyst(data, hyst_mc);
+ u32 ctrl1;
+
+ regmap_read(priv->syscon, data->syscon_control1_off, &ctrl1);
+
+ /* Set Threshold */
+ if (thresh_mc >= 0) {
+ ctrl1 &= ~(data->temp_mask << data->thresh_shift);
+ ctrl1 |= threshold << data->thresh_shift;
+ priv->current_threshold = thresh_mc;
+ }
+
+ /* Set Hysteresis */
+ if (hyst_mc >= 0) {
+ ctrl1 &= ~(data->hyst_mask << data->hyst_shift);
+ ctrl1 |= hysteresis << data->hyst_shift;
+ priv->current_hysteresis = hyst_mc;
+ }
+
+ regmap_write(priv->syscon, data->syscon_control1_off, ctrl1);
+}
+
+static irqreturn_t armada_overheat_isr(int irq, void *blob)
+{
+ /*
+ * Disable the IRQ and continue in thread context (thermal core
+ * notification and temperature monitoring).
+ */
+ disable_irq_nosync(irq);
+
+ return IRQ_WAKE_THREAD;
+}
+
+static irqreturn_t armada_overheat_isr_thread(int irq, void *blob)
+{
+ struct armada_thermal_priv *priv = blob;
+ int low_threshold = priv->current_threshold - priv->current_hysteresis;
+ int temperature;
+ u32 dummy;
+ int ret;
+
+ /* Notify the core in thread context */
+ thermal_zone_device_update(priv->overheat_sensor,
+ THERMAL_EVENT_UNSPECIFIED);
+
+ /*
+ * The overheat interrupt must be cleared by reading the DFX interrupt
+ * cause _after_ the temperature has fallen down to the low threshold.
+ * Otherwise future interrupts might not be served.
+ */
+ do {
+ msleep(OVERHEAT_INT_POLL_DELAY_MS);
+ mutex_lock(&priv->update_lock);
+ ret = armada_read_sensor(priv, &temperature);
+ mutex_unlock(&priv->update_lock);
+ if (ret)
+ goto enable_irq;
+ } while (temperature >= low_threshold);
+
+ regmap_read(priv->syscon, priv->data->dfx_irq_cause_off, &dummy);
+
+ /* Notify the thermal core that the temperature is acceptable again */
+ thermal_zone_device_update(priv->overheat_sensor,
+ THERMAL_EVENT_UNSPECIFIED);
+
+enable_irq:
+ enable_irq(irq);
+
+ return IRQ_HANDLED;
+}
+
git.samba.org / sfrench / cifs-2.6.git / blobdiff