[PATCH v7 5/7] PCI: Add T_PERST_CLK_US macro

Thomas Richard
2024-06-19T10:15:48Z

"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@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 fd44565c4756..1a11f2fe3efe 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