Re: [PATCH v2 1/2] gpio: tps65219: add GPIO support for TPS65219 PMIC

From: jerome Neanne
Date: Fri May 12 2023 - 03:16:12 EST




On 11/05/2023 22:57, Linus Walleij wrote:
+ /* Documentation is stating that GPIO0 direction must not be changed in Linux:
+ * Table 8-34. MFP_1_CONFIG(3): MULTI_DEVICE_ENABLE,
+ * Should only be changed in INITIALIZE state (prior to ON Request).
+ * Set statically by NVM, changing direction in application can cause a hang.
+ * Below can be used for test purpose only:
+ */
+
+#if 0
+ int ret = regmap_update_bits(gpio->tps->regmap, TPS65219_REG_MFP_1_CONFIG,
+ TPS65219_GPIO0_DIR_MASK, direction);
+ if (ret)
+ return ret;
+#endif
+ dev_err(gpio->tps->dev,
+ "GPIO%d direction set by NVM, change to %u failed, not allowed by specification\n",
+ offset, direction);
+ return -EOPNOTSUPP;
+}

Normally people would complain about #if 0 code.

But this is a special case!

I definitely want the code to be in there somehow.

What about:

if (IS_ENABLED(DEBUG))?

If someone enables debug with an explicit -DDEBUG to the compiler
this could be allowed.
I'm fine with your proposal. Will wait few days just in case anyone wants to add any comment then go for this.