[PATCH v5 09/11] PCI: Add T_PERST_CLK_US macro

[Thomas Richard]

"Power Sequencing and Reset Signal Timings" table (section 2.9.2) in PCI
EXPRESS CARD ELECTROMECHANICAL SPECIFICATION, REV. 5.1 indicates PERST#
should be deasserted after minimum of 100us once REFCLK is stable (symbol
T_PERST-CLK).

Add a macro so that PCIe controller drivers can use it.

Signed-off-by: Thomas Richard <thomas.richard at bootlin.com>
---
 drivers/pci/pci.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 17fed1846847..c47b1d3b5887 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -16,6 +16,9 @@
 /* Power stable to PERST# inactive from PCIe card Electromechanical Spec */
 #define PCIE_T_PVPERL_MS		100
 
+/* REFCLK stable before PERST# inactive from PCIe card Electromechanical Spec */
+#define PCIE_T_PERST_CLK_US		100
+
 /*
  * PCIe r6.0, sec 5.3.3.2.1 <PME Synchronization>
  * Recommends 1ms to 10ms timeout to check L2 ready.

-- 
2.39.2