Re: [PATCH v3 2/3] x86/platform/p2sb: New Primary to Sideband bridge support driver for Intel SOC's
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: 2016-06-13 13:53:36
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On Thu, 2016-06-09 at 17:05 +0300, Mika Westerberg wrote:
On Tue, Jun 07, 2016 at 02:55:52PM +0800, Tan Jui Nee wrote:quoted
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com> There is already one and at least one more user coming which require an access to Primary to Sideband bridge (P2SB) in order to get IO or MMIO bar hidden by BIOS. Create a driver to access P2SB for x86 devices. Signed-off-by: Yong, Jonathan <redacted> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> --- arch/x86/Kconfig | 14 ++++++ arch/x86/include/asm/p2sb.h | 27 +++++++++++ arch/x86/platform/intel/Makefile | 1 + arch/x86/platform/intel/p2sb.c | 99 ++++++++++++++++++++++++++++++++++++++++ 4 files changed, 141 insertions(+) create mode 100644 arch/x86/include/asm/p2sb.h create mode 100644 arch/x86/platform/intel/p2sb.cdiff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 2dc18605..589045e 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig@@ -606,6 +606,20 @@ config IOSF_MBI_DEBUGIf you don't require the option or are in doubt, say N. +config X86_INTEL_NON_ACPI + bool "Enable support non-ACPI Intel platforms" + select PINCTRL + ---help--- + Select this option to enables MMIO BAR access over the P2SB for + non-ACPI Intel SoC platforms. This driver uses the P2SB hide/unhide + mechanism cooperatively to pass the PCI BAR address to the platform + driver, currently GPIO on the following SoC products. + - Apollo LakeWhy do we need Kconfig option for this?
In one of previous review I was wondering how we could not to build this at all. I don't like this option either.
I think better is to make P2SB available on CPUs which have one, and that can be detected runtime. If P2SB is not available then p2sb_bar() returns -ENODEV.
Would work to me, though still the same question: is it possible to avoid building it on even most of Intel platforms, since there, I assume, will be not many users of the module? -- Andy Shevchenko [off-list ref] Intel Finland Oy -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html