[coreboot-gerrit] [S] Change in coreboot[master]: drivers/uart/acpi: Drop 'disable_gpio_export_in_crs' flag

[Martin L Roth (Code Review)]

Martin L Roth has submitted this change. ( https://review.coreboot.org/c/coreboot/+/71851 )

(

1 is the latest approved patch-set.
No files were changed between the latest approved patch-set and the submitted one.
 )Change subject: drivers/uart/acpi: Drop 'disable_gpio_export_in_crs' flag
......................................................................

drivers/uart/acpi: Drop 'disable_gpio_export_in_crs' flag

Exposing the GPIOs via an ACPI PowerResource and the _CRS results in the
OS driver and ACPI thinking they own the GPIO. This can cause timing
problems because it's not clear which system should be controlling the
GPIO.

There's no reason to require explicit disablement however, so drop the
superfluous 'disable' flag, and change the _CRS generation to check if
the GPIOs will be exported via the 'has_power_resource' flag instead.

This mirrors the change made for drivers/i2c/generic.

TEST=untested, as no boards selected this option.

Change-Id: Icb60502a4a7c5e7a1fcf1ee60e23c77e00d6de7b
Signed-off-by: Matt DeVillier 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/71851
Reviewed-by: Martin L Roth 
Tested-by: build bot (Jenkins) 
---
M src/drivers/uart/acpi/acpi.c
M src/drivers/uart/acpi/chip.h
2 files changed, 28 insertions(+), 5 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Martin L Roth: Looks good to me, approved

diff --git a/src/drivers/uart/acpi/acpi.c b/src/drivers/uart/acpi/acpi.c
index 3081182..c43dc52 100644
--- a/src/drivers/uart/acpi/acpi.c
+++ b/src/drivers/uart/acpi/acpi.c
@@ -11,10 +11,10 @@
 {
    /*
     * Return false if:
-	 * 1. Request to explicitly disable export of GPIOs in CRS, or
+	 * 1. GPIOs are exported via a power resource, or
     * 2. Both reset and enable GPIOs are not provided.
     */
-	if (config->disable_gpio_export_in_crs ||
+	if (config->has_power_resource ||
        ((config->reset_gpio.pin_count == 0) &&
         (config->enable_gpio.pin_count == 0)))
    	return false;
diff --git a/src/drivers/uart/acpi/chip.h b/src/drivers/uart/acpi/chip.h
index 0311165..6c7d267 100644
--- a/src/drivers/uart/acpi/chip.h
+++ b/src/drivers/uart/acpi/chip.h
@@ -17,9 +17,6 @@
    struct acpi_gpio irq_gpio;	/* GPIO to be used instead of PIRQ */
    struct acpi_uart uart;		/* UART device information */

-	/* Disable reset and enable GPIO export in _CRS */
-	bool disable_gpio_export_in_crs;
-
    /* Does the device have a power resource? */
    bool has_power_resource;