On Sat, 31 Jul 2021 19:31:52 +0100
"Lad, Prabhakar" [off-list ref] wrote:

Hi Jonathan,

Thank you for the review.

...

quoted

quoted

+#define DRIVER_NAME          "rzg2l-adc"  

As only used in one place, just put it inline there so we don't need
to go find if we want to know the value - I'm lazy.
 

Its being used in two places
1: indio_dev->name = DRIVER_NAME #In probe call
2: .name = DRIVER_NAME # In platform_driver struct

Let me know if you want me to replace them inline and drop the above macro.

oops.  Searching apparently failed me ;)  Fine as is.

...

quoted

quoted

+static const struct iio_info rzg2l_adc_iio_info = {
+     .read_raw = rzg2l_adc_read_raw,
+     .read_label = rzg2l_adc_read_label,
+};
+
+static irqreturn_t rzg2l_adc_isr(int irq, void *dev_id)
+{
+     struct rzg2l_adc *adc = (struct rzg2l_adc *)dev_id;  

No need for explicit cast from void * to another pointer type.
This is always valid without in C.
 

Agreed.

quoted

quoted

+     unsigned long intst;
+     u32 reg;
+     int ch;
+
+     reg = rzg2l_adc_readl(adc, RZG2L_ADSTS);
+
+     /* A/D conversion channel select error interrupt */
+     if (reg & RZG2L_ADSTS_CSEST) {
+             rzg2l_adc_writel(adc, RZG2L_ADSTS, reg);
+             return IRQ_HANDLED;
+     }
+
+     intst = reg & RZG2L_ADSTS_INTST_MASK;
+     if (!intst)
+             return IRQ_NONE;
+
+     for_each_set_bit(ch, &intst, RZG2L_ADC_MAX_CHANNELS) {
+             if (intst & BIT(ch))  

I'm missing how this if can fail given we only end up in here when the bit is
set.
 

ADC has 8 channels RZG2L_ADSTS register bits [0:7] will be set to 1
when the given channel ADC conversion has been completed. So the above
if condition checks if the bit is set to 1 and then reads the
corresponding value of that channel.

Just looking at the two lines of code above
for_each_set_bit(ch, &intst, RZG2L_ADC_MAX_CHANNELS) 
will only call the the next line if the bit is set.  E.g. It will only call
it
if (intst & BIT(ch))

So you can only get into the body of the for loop if this bit is set and the
condition is always true.  Hence drop 
if (intst & BIT(ch)) 

quoted

quoted

+                     adc->last_val[ch] = rzg2l_adc_readl(adc, RZG2L_ADCR(ch)) &
+                                         RZG2L_ADCR_AD_MASK;
+     }
+
+     /* clear the channel interrupt */
+     rzg2l_adc_writel(adc, RZG2L_ADSTS, reg);
+
+     complete(&adc->completion);
+
+     return IRQ_HANDLED;
+}
+

...

quoted

quoted

+
+     pm_runtime_enable(dev);  

I think you also want to set the state to suspended to ensure the resume is
called on get.
 

pm_runtime_set_suspended() should only be called when runtime is
disabled or is it that I am missing something ?

If you want the runtime pm code to assume your device is suspended initially
then you set the state before you call pm_runtime_enable(dev).


J