Re: [PATCH] pinctrl: stm32: improve bank clocks management

From: Marek Vasut
Date: Mon Apr 25 2022 - 18:24:36 EST

On 4/25/22 11:27, Fabien DESSENNE wrote:
Hi Marek

On 22/04/2022 18:26, Marek Vasut wrote:
On 4/22/22 16:36, Fabien Dessenne wrote:
Instead of enabling/disabling the clock at each IO configuration update,
just keep the clock enabled from the probe.
This makes things simpler and more efficient (e.g. the time required to
toggle an output IO is drastically decreased) without significantly
increasing the power consumption.


  static struct irq_domain *stm32_pctrl_get_irq_domain(struct device_node *np)
@@ -1575,6 +1537,10 @@ int stm32_pctl_probe(struct platform_device *pdev)
              ret = stm32_gpiolib_register_bank(pctl, child);
              if (ret) {
+                for (i = 0; i < pctl->nbanks; i++)
+                    clk_disable_unprepare(pctl->banks[i].clk);

There are clk_bulk_*() functions, maybe you can use those to get rid of these loops ?

This sounds goods, but checking more in details I see that moving to the 'bulk' implementation would require to move the clk information from the "struct stm32_gpio_bank *banks" member to its parent "struct stm32_pinctrl".

This would make the clk device information stored in a different structure from the other device-related information (base address, reset control, ...). It's better to keep all those information together in the same struct.

As another drawback we would loose access to 'clk' from any function that have 'bank' (or 'struct gpio_chip *chip') as input parameter (e.g. stm32_gpio_get() called from gpiolib).

So I really prefer to keep the current implementation.

All right, I agree.

The rest looks good to me.

Reviewed-by: Marek Vasut <marex@xxxxxxx>