Re: [PATCH v2 15/15] drivers: thermal: tsens: Add interrupt support

Stephen Boyd
2019-08-28T21:42:32Z

Quoting Amit Kucheria (2019-08-27 05:14:11)
> diff --git a/drivers/thermal/qcom/tsens-common.c b/drivers/thermal/qcom/tsens-common.c
> index 06b44cfd5eab9..c549f8e1488ba 100644
> --- a/drivers/thermal/qcom/tsens-common.c
> +++ b/drivers/thermal/qcom/tsens-common.c
> @@ -114,6 +146,314 @@ static int tsens_hw_to_mC(struct tsens_sensor *s, int field)
> return sign_extend32(temp, priv->tempres) * 100;
> }
>
> +/**
> + * tsens_mC_to_hw - Return correct value to be written to threshold
> + * registers, whether in ADC code or deciCelsius depending on IP version

Document arguments and return value? Maybe summary can be 'convert
tsens temperature to hardware register value'?

> + */
> +static int tsens_mC_to_hw(struct tsens_sensor *s, int temp)
> +{
> + struct tsens_priv *priv = s->priv;
> +
> + if (priv->feat->adc) {
> + /* milliC to C to adc code */
> + return degc_to_code(temp / 1000, s);
> + }
> +
> + /* milliC to deciC */
> + return temp / 100;
> +}
> +
> +static inline unsigned int tsens_ver(struct tsens_priv *priv)

Can this return the enum instead of unsigned int?

> +{
> + return priv->feat->ver_major;
> +}
> +
> +/**
> + * tsens_set_interrupt_v1 - Disable an interrupt (enable = false)
> + * Re-enable an interrupt (enable = true)
> + */
> +static void tsens_set_interrupt_v1(struct tsens_priv *priv, u32 hw_id,
> + enum tsens_irq_type irq_type, bool enable)
> +{
> + u32 index;
> +
> + if (enable) {
> + switch (irq_type) {
> + case UPPER:
> + index = UP_INT_CLEAR_0 + hw_id;
> + break;
> + case LOWER:
> + index = LOW_INT_CLEAR_0 + hw_id;
> + break;
> + }
> + regmap_field_write(priv->rf[index], 0);
> + } else {
> + switch (irq_type) {
> + case UPPER:
> + index = UP_INT_CLEAR_0 + hw_id;
> + break;
> + case LOWER:
> + index = LOW_INT_CLEAR_0 + hw_id;
> + break;
> + }
> + regmap_field_write(priv->rf[index], 1);
> + }

De-dup the switch statement and have

regmap_field_write(priv->rf[index], enable ? 1 : 0);

> +}
> +
> +/**
> + * tsens_set_interrupt_v2 - Disable an interrupt (enable = false)
> + * Re-enable an interrupt (enable = true)
> + */
> +static void tsens_set_interrupt_v2(struct tsens_priv *priv, u32 hw_id,
> + enum tsens_irq_type irq_type, bool enable)
> +{
> + u32 index_mask, index_clear;
> +
> + if (enable) {
> + switch (irq_type) {
> + case UPPER:
> + index_mask = UP_INT_MASK_0 + hw_id;
> + break;
> + case LOWER:
> + index_mask = LOW_INT_MASK_0 + hw_id;
> + break;
> + }
> + regmap_field_write(priv->rf[index_mask], 0);
> + } else {
> + /* To disable the interrupt flag for a sensor:

Nitpick: Wrong comment style.

> + * 1. Mask further interrupts for this sensor
> + * 2. Write 1 followed by 0 to clear the interrupt
> + */
> + switch (irq_type) {
> + case UPPER:
> + index_mask = UP_INT_MASK_0 + hw_id;
> + index_clear = UP_INT_CLEAR_0 + hw_id;
> + break;
> + case LOWER:
> + index_mask = LOW_INT_MASK_0 + hw_id;
> + index_clear = LOW_INT_CLEAR_0 + hw_id;
> + break;
> + }

Please extract index_mask and index_clear assignments to one switch
statement and then change the sequence to an if/else

if (enable) {
regmap_field_write(priv->rf[index_mask], 1);
regmap_field_write(priv->rf[index_clear], 1);
regmap_field_write(priv->rf[index_clear], 0);
} else {
regmap_field_write(priv->rf[index_mask], 0);
}

> +}
> +
> +/**
> + * tsens_set_interrupt - Disable an interrupt (enable = false)
> + * Re-enable an interrupt (enable = true)
> + */
> +static void tsens_set_interrupt(struct tsens_priv *priv, u32 hw_id,
> + enum tsens_irq_type irq_type, bool enable)
> +{
> + dev_dbg(priv->dev, "[%u] %s: %s -> %s\n", hw_id, __func__,
> + irq_type ? ((irq_type == 1) ? "UP" : "CRITICAL") : "LOW",
> + enable ? "en" : "dis");
> + if (tsens_ver(priv) > VER_1_X)
> + tsens_set_interrupt_v2(priv, hw_id, irq_type, enable);
> + else
> + tsens_set_interrupt_v1(priv, hw_id, irq_type, enable);
> +}
> +
> +/**
> + * tsens_threshold_violated - Check if a sensor temperature violated a preset threshold
> + *

Document arguments?

> + * Return: 0 if threshold was not violated, 1 if it was violated and negative
> + * errno in case of errors
> + */
> +static int tsens_threshold_violated(struct tsens_priv *priv, u32 hw_id,
> + struct tsens_irq_data *d)
> +{
> + int ret;
> +
> + ret = regmap_field_read(priv->rf[UPPER_STATUS_0 + hw_id], &d->up_viol);
> + if (ret)
> + return ret;
> + ret = regmap_field_read(priv->rf[LOWER_STATUS_0 + hw_id], &d->low_viol);
> + if (ret)
> + return ret;
> + if (d->up_viol || d->low_viol)
> + return 1;
> +
> + return 0;
> +}
> +
> +static int tsens_read_irq_state(struct tsens_priv *priv, u32 hw_id,
> + struct tsens_sensor *s, struct tsens_irq_data *d)
> +{
> + int ret;
> +
> + ret = regmap_field_read(priv->rf[UP_INT_CLEAR_0 + hw_id], &d->up_irq_clear);
> + if (ret)
> + return ret;
> + ret = regmap_field_read(priv->rf[LOW_INT_CLEAR_0 + hw_id], &d->low_irq_clear);
> + if (ret)
> + return ret;
> + if (tsens_ver(priv) > VER_1_X) {
> + ret = regmap_field_read(priv->rf[UP_INT_MASK_0 + hw_id], &d->up_irq_mask);
> + if (ret)
> + return ret;
> + ret = regmap_field_read(priv->rf[LOW_INT_MASK_0 + hw_id], &d->low_irq_mask);
> + if (ret)
> + return ret;
> + } else {
> + /* No mask register on older TSENS */
> + d->up_irq_mask = 0;
> + d->low_irq_mask = 0;
> + }
> +
> + d->up_thresh = tsens_hw_to_mC(s, UP_THRESH_0 + hw_id);
> + d->low_thresh = tsens_hw_to_mC(s, LOW_THRESH_0 + hw_id);
> +
> + dev_dbg(priv->dev, "[%u] %s%s: status(%u|%u) | clr(%u|%u) | mask(%u|%u)\n",
> + hw_id, __func__, (d->up_viol || d->low_viol) ? "(V)" : "",
> + d->low_viol, d->up_viol, d->low_irq_clear, d->up_irq_clear,
> + d->low_irq_mask, d->up_irq_mask);
> + dev_dbg(priv->dev, "[%u] %s%s: thresh: (%d:%d)\n", hw_id, __func__,
> + (d->up_viol || d->low_viol) ? "(violation)" : "",
> + d->low_thresh, d->up_thresh);
> +
> + return 0;
> +}
> +
> +static inline u32 masked_irq(u32 hw_id, u32 mask, enum tsens_ver ver)
> +{
> + if (ver > VER_1_X)
> + return mask & (1 << hw_id);
> +
> + /* v1, v0.1 don't have a irq mask register */
> + return 0;
> +}
> +
> +irqreturn_t tsens_irq_thread(int irq, void *data)
> +{
> + struct tsens_priv *priv = data;
> + struct tsens_irq_data d;
> + bool enable = true, disable = false;
> + unsigned long flags;
> + int temp, ret, i;
> +
> + /*
> + * Check if any sensor raised an IRQ - for each sensor connected to the
> + * TSENS block if it set the threshold violation bit.
> + */
> + for (i = 0; i < priv->num_sensors; i++) {
> + bool trigger = 0;

How about trigger = false? It's a bool.

> + struct tsens_sensor *s = &priv->sensor[i];
> + u32 hw_id = s->hw_id;
> +
> + if (IS_ERR(priv->sensor[i].tzd))
> + continue;
> + if (!tsens_threshold_violated(priv, hw_id, &d))
> + continue;
> + ret = get_temp_tsens_valid(s, &temp);
> + if (ret) {
> + dev_err(priv->dev, "[%u] %s: error reading sensor\n", hw_id, __func__);

I hope there isn't an interrupt storm where we're trying to print out
messages from the irq handler.

> + continue;
> + }
> +
> + spin_lock_irqsave(&priv->ul_lock, flags);
> +
> + tsens_read_irq_state(priv, hw_id, s, &d);
> +
> + if (d.up_viol &&
> + !masked_irq(hw_id, d.up_irq_mask, tsens_ver(priv))) {
> + tsens_set_interrupt(priv, hw_id, UPPER, disable);
> + if (d.up_thresh > temp) {
> + dev_dbg(priv->dev, "[%u] %s: re-arm upper\n",
> + priv->sensor[i].hw_id, __func__);
> + /* unmask the interrupt for this sensor */
> + tsens_set_interrupt(priv, hw_id, UPPER, enable);
> + } else {
> + trigger = 1;
> + /* Keep irq masked */
> + }
> + } else if (d.low_viol &&
> + !masked_irq(hw_id, d.low_irq_mask, tsens_ver(priv))) {
> + tsens_set_interrupt(priv, hw_id, LOWER, disable);
> + if (d.low_thresh < temp) {
> + dev_dbg(priv->dev, "[%u] %s: re-arm low\n",
> + priv->sensor[i].hw_id, __func__);
> + /* unmask the interrupt for this sensor */
> + tsens_set_interrupt(priv, hw_id, LOWER, enable);
> + } else {
> + trigger = 1;
> + /* Keep irq masked */
> + }
> + }
> +
> + spin_unlock_irqrestore(&priv->ul_lock, flags);
> +
> + if (trigger) {
> + dev_dbg(priv->dev, "[%u] %s: TZ update trigger (%d mC)\n",
> + hw_id, __func__, temp);
> + thermal_zone_device_update(priv->sensor[i].tzd,
> + THERMAL_EVENT_UNSPECIFIED);
> + } else {
> + dev_dbg(priv->dev, "[%u] %s: no violation: %d\n",
> + hw_id, __func__, temp);
> + }
> + }
> +
> + return IRQ_HANDLED;

Should we return IRQ_NONE in the case that the above for loop didn't
find anything in those if/else-ifs?

> +}
> +
> +int tsens_set_trips(void *_sensor, int low, int high)
> +{
> + struct tsens_sensor *s = _sensor;
> + struct tsens_priv *priv = s->priv;
> + struct device *dev = priv->dev;
> + struct tsens_irq_data d;
> + unsigned long flags;
> + int high_val, low_val, cl_high, cl_low;
> + bool enable = true;
> + u32 hw_id = s->hw_id;
> +
> + dev_dbg(dev, "[%u] %s: proposed thresholds: (%d:%d)\n",
> + hw_id, __func__, low, high);
> +
> + cl_high = clamp_val(high, -40000, 120000);
> + cl_low = clamp_val(low, -40000, 120000);
> +
> + high_val = tsens_mC_to_hw(s, cl_high);
> + low_val = tsens_mC_to_hw(s, cl_low);
> +
> + spin_lock_irqsave(&priv->ul_lock, flags);
> +
> + tsens_read_irq_state(priv, hw_id, s, &d);
> +
> + /* Write the new thresholds and clear the status */
> + regmap_field_write(priv->rf[LOW_THRESH_0 + hw_id], low_val);
> + regmap_field_write(priv->rf[UP_THRESH_0 + hw_id], high_val);
> + tsens_set_interrupt(priv, hw_id, LOWER, enable);
> + tsens_set_interrupt(priv, hw_id, UPPER, enable);

Just pass true? Why is there an enable local variable?

> +
> + spin_unlock_irqrestore(&priv->ul_lock, flags);
> +
> + dev_dbg(dev, "[%u] %s: (%d:%d)->(%d:%d)\n",
> + s->hw_id, __func__, d.low_thresh, d.up_thresh, cl_low, cl_high);
> +
> + return 0;
> +}
> +
[...]
> @@ -319,28 +659,31 @@ int __init init_common(struct tsens_priv *priv)
> ret = PTR_ERR(priv->rf[SENSOR_EN]);
> goto err_put_device;
> }
> - /* now alloc regmap_fields in tm_map */
> - for (i = 0, j = LAST_TEMP_0; i < priv->feat->max_sensors; i++, j++) {
> - priv->rf[j] = devm_regmap_field_alloc(dev, priv->tm_map,
> - priv->fields[j]);
> - if (IS_ERR(priv->rf[j])) {
> - ret = PTR_ERR(priv->rf[j]);
> - goto err_put_device;
> - }
> + priv->rf[INT_EN] = devm_regmap_field_alloc(dev, priv->tm_map,
> + priv->fields[INT_EN]);
> + if (IS_ERR(priv->rf[INT_EN])) {
> + ret = PTR_ERR(priv->rf[INT_EN]);
> + goto err_put_device;
> }
>
> - /* Save away resolution of signed temperature value for this IP */
> - priv->tempres = priv->fields[LAST_TEMP_0].msb - priv->fields[LAST_TEMP_0].lsb;
> -
> - for (i = 0, j = VALID_0; i < priv->feat->max_sensors; i++, j++) {
> - priv->rf[j] = devm_regmap_field_alloc(dev, priv->tm_map,
> - priv->fields[j]);
> - if (IS_ERR(priv->rf[j])) {
> - ret = PTR_ERR(priv->rf[j]);
> - goto err_put_device;
> + /* This loop might need changes if enum regfield_ids is reordered */
> + for (j = LAST_TEMP_0; j <= UP_THRESH_15; j += 16) {
> + for (i = 0; i < priv->feat->max_sensors; i++) {
> + int idx = j + i;
> +
> + priv->rf[idx] = devm_regmap_field_alloc(dev, priv->tm_map,
> + priv->fields[idx]);
> + if (IS_ERR(priv->rf[idx])) {
> + ret = PTR_ERR(priv->rf[idx]);
> + goto err_put_device;
> + }
> }
> }
> + /* Save away resolution of signed temperature value for this IP */
> + priv->tempres = priv->fields[LAST_TEMP_0].msb - priv->fields[LAST_TEMP_0].lsb;

Leave this where it was, i.e. before the for loop? Or is that a bug and
it doesn't actually work unless it's after the for loop? In which case,
this should go to the previous patch.

>
> + spin_lock_init(&priv->ul_lock);
> + tsens_enable_irq(priv);
> tsens_debug_init(op);
>
> return 0;
> diff --git a/drivers/thermal/qcom/tsens.c b/drivers/thermal/qcom/tsens.c
> index 772aa76b50e12..a4335717aeede 100644
> --- a/drivers/thermal/qcom/tsens.c
> +++ b/drivers/thermal/qcom/tsens.c
> @@ -96,7 +99,33 @@ static int tsens_register(struct tsens_priv *priv)
> if (priv->ops->enable)
> priv->ops->enable(priv, i);
> }
> +
> + pdev = of_find_device_by_node(priv->dev->of_node);
> + if (!pdev) {
> + dev_err(&pdev->dev, "%s: device node not found in DT\n", __func__);

Do we really need this? Maybe just bail out in silence because this
should never happen?

> + return -ENODEV;
> + }
> +
> + irq = platform_get_irq_byname(pdev, "uplow");
> + if (irq < 0) {
> + dev_err(&pdev->dev, "%s: missing irq in dt: uplow\n", __func__);

You can drop the error print. I upstreamed a change to print the error
generically in the core.

> + return irq;

Did we need to put_device() here?

> + }
> +
> + ret = devm_request_threaded_irq(&pdev->dev, irq,
> + NULL, tsens_irq_thread,
> + IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
> + dev_name(&pdev->dev), priv);
> + if (ret) {
> + dev_err(&pdev->dev, "%s: failed to get irq\n", __func__);
> + goto err_put_device;
> + }
> + enable_irq_wake(irq);
> return 0;
> +
> +err_put_device:
> + put_device(&pdev->dev);
> + return ret;