Thread (7 messages) 7 messages, 3 authors, 2021-08-16

Re: [PATCH v1 1/1] x86/platform: Increase maximum GPIO number for X86_64

From: "Rafael J. Wysocki" <rafael@kernel.org>
Date: 2021-08-16 13:33:36
Also in: linux-gpio, lkml

On Fri, Aug 6, 2021 at 4:44 PM Andy Shevchenko
[off-list ref] wrote:
quoted hunk ↗ jump to hunk
By default the 512 GPIOs is a maximum on any x86 platform.
With, for example, Intel Tiger Lake-H the SoC based controller
occupies up to 480 pins. This leaves only 32 available for
GPIO expanders or other drivers, like PMIC. Hence, bump the
maximum GPIO number to 1024 for X86_64 and leave 512 for X86_32.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 arch/x86/Kconfig | 13 +++++++++++++
 1 file changed, 13 insertions(+)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 45962aaf2b2c..495ed6229b52 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -340,6 +340,19 @@ config NEED_PER_CPU_PAGE_FIRST_CHUNK
 config ARCH_HIBERNATION_POSSIBLE
        def_bool y

+# The GPIO number here must be sorted by descending number. In case of
+# a multiplatform kernel, we just want the highest value required by the
+# selected platforms.
+config ARCH_NR_GPIO
+       int
+       default 1024 if X86_64
+       default 512 if X86_32
+       default 0
Wouldn't

default 1024 if X86_64
default 512

be sufficient?

It's either X86_64 or X86_32 anyway AFAICS.
+       help
+         Maximum number of GPIOs in the system.
+
+         If unsure, leave the default value.
+
 config ARCH_SUSPEND_POSSIBLE
        def_bool y

--
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