[S] Change in flashrom[main]: chipset_enable.c: Use PCI_ACCESS_ECAM to access pci register

[Peter Marheine (Code Review)]

Peter Marheine has submitted this change. ( https://review.coreboot.org/c/flashrom/+/83896?usp=email )

Change subject: chipset_enable.c: Use PCI_ACCESS_ECAM to access pci register
......................................................................

chipset_enable.c: Use PCI_ACCESS_ECAM to access pci register

In the latest pciutils(v3.13.0), it supports accessing pci registers
by ecam. This patch uses libpci version check to decide whether
flashrom calls libpci and use 0xcf8/0xcfc or ecam to access pci
registers.

BUG=b:359813524
TEST=with libpci >= 3.13.0, flashrom is working with ECAM access

Change-Id: I4549f87c8b01da0a1d3d8ce0b3b75c1f5fa2cbab
Signed-off-by: Kane Chen 
Reviewed-on: https://review.coreboot.org/c/flashrom/+/83896
Tested-by: build bot (Jenkins) 
Reviewed-by: Hsuan-ting Chen 
Reviewed-by: Peter Marheine 
---
M chipset_enable.c
M doc/release_notes/devel.rst
M meson.build
3 files changed, 22 insertions(+), 1 deletion(-)

Approvals:
  Hsuan-ting Chen: Looks good to me, approved
  Peter Marheine: Looks good to me, approved
  build bot (Jenkins): Verified

diff --git a/chipset_enable.c b/chipset_enable.c
index facf29e..9f0a0bb 100644
--- a/chipset_enable.c
+++ b/chipset_enable.c
@@ -938,7 +938,13 @@
    	msg_perr("Can't allocate PCI accessor.\n");
    	return ret;
    }
+#if CONFIG_USE_LIBPCI_ECAM == 1
+	pci_acc->method = PCI_ACCESS_ECAM;
+	msg_pdbg("Using libpci PCI_ACCESS_ECAM\n");
+#else
    pci_acc->method = PCI_ACCESS_I386_TYPE1;
+	msg_pdbg("Using libpci PCI_ACCESS_I386_TYPE1\n");
+#endif
    pci_init(pci_acc);
    register_shutdown(enable_flash_pch100_shutdown, pci_acc);

diff --git a/doc/release_notes/devel.rst b/doc/release_notes/devel.rst
index e28e347..5243f7c 100644
--- a/doc/release_notes/devel.rst
+++ b/doc/release_notes/devel.rst
@@ -22,4 +22,12 @@

As documented in the :doc:`v1.4 release notes <v_1_4>`, support for building
 flashrom with make has been removed; all Makefiles have been deleted. Meson is
-now the only supported tool for building flashrom from source.
\ No newline at end of file
+now the only supported tool for building flashrom from source.
+
+New Feature
+===========
+Libpci 3.13.0 and onwards support ECAM to access pci registers. Flashrom will
+be moved to ECAM from IO port 0xcf8/0xcfc if the libpci version is >= 3.13.0.
+The ECAM has been supported for a very long time, most platforms should support
+it. For those platforms don't support ECAM, libpci will terminate the process by
+exit.
diff --git a/meson.build b/meson.build
index 85d69b8..26d96d9 100644
--- a/meson.build
+++ b/meson.build
@@ -165,6 +165,13 @@
 libftdi1   = dependency('libftdi1', required : group_ftdi)
 libjaylink = dependency('libjaylink', required : group_jlink, version : '>=0.3.0')

+# ECAM is supported in libpci after 3.13.0
+if libpci.version().version_compare('>=3.13.0')
+    add_project_arguments('-DCONFIG_USE_LIBPCI_ECAM=1', language: 'c')
+else
+    add_project_arguments('-DCONFIG_USE_LIBPCI_ECAM=0', language: 'c')
+endif
+
 if host_machine.system() == 'windows'
   # Specifying an include_path that doesn't exist is an error,
   # but we only use this if the library is found in the same directory.