net: stmmac: Add generic suspend/resume helper for PCI-based controllers

Most glue driver for PCI-based DWMAC controllers utilize similar
platform suspend/resume routines. Add a generic implementation to reduce
duplicated code.

Signed-off-by: Yao Zi <ziyao@disroot.org>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Yanteng Si <siyanteng@cqsoftware.com.cn>
Link: https://patch.msgid.link/20251124160417.51514-2-ziyao@disroot.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/stmicro/stmmac/Kconfig b/drivers/net/ethernet/stmicro/stmmac/Kconfig
index 87c5bea6c2a243f3be998b2c3935bc1dc23bfe22..15ed5c1d071a08be7b89680087a3175df46dab16 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/Kconfig
+++ b/drivers/net/ethernet/stmicro/stmmac/Kconfig
@@ -349,6 +349,11 @@ config DWMAC_VISCONTI
 
 endif
 
+config STMMAC_LIBPCI
+       tristate
+       help
+         This option enables the PCI bus helpers for the stmmac driver.
+
 config DWMAC_INTEL
        tristate "Intel GMAC support"
        default X86

diff --git a/drivers/net/ethernet/stmicro/stmmac/Makefile b/drivers/net/ethernet/stmicro/stmmac/Makefile
index 1681a8a2831354b15391fd6e38c6bdf551a1041f..7bf528731034b64281248bc5f39fd60e52d43e9c 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/Makefile
+++ b/drivers/net/ethernet/stmicro/stmmac/Makefile
@@ -44,6 +44,7 @@ obj-$(CONFIG_DWMAC_VISCONTI)  += dwmac-visconti.o
 stmmac-platform-objs:= stmmac_platform.o
 dwmac-altr-socfpga-objs := dwmac-socfpga.o
 
+obj-$(CONFIG_STMMAC_LIBPCI)    += stmmac_libpci.o
 obj-$(CONFIG_STMMAC_PCI)       += stmmac-pci.o
 obj-$(CONFIG_DWMAC_INTEL)      += dwmac-intel.o
 obj-$(CONFIG_DWMAC_LOONGSON)   += dwmac-loongson.o

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_libpci.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_libpci.c
new file mode 100644 (file)
index 0000000..5c5dd50
--- /dev/null
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_libpci.c
@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * PCI bus helpers for STMMAC driver
+ * Copyright (C) 2025 Yao Zi <ziyao@disroot.org>
+ */
+
+#include <linux/device.h>
+#include <linux/pci.h>
+
+#include "stmmac_libpci.h"
+
+int stmmac_pci_plat_suspend(struct device *dev, void *bsp_priv)
+{
+       struct pci_dev *pdev = to_pci_dev(dev);
+       int ret;
+
+       ret = pci_save_state(pdev);
+       if (ret)
+               return ret;
+
+       pci_disable_device(pdev);
+       pci_wake_from_d3(pdev, true);
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(stmmac_pci_plat_suspend);
+
+int stmmac_pci_plat_resume(struct device *dev, void *bsp_priv)
+{
+       struct pci_dev *pdev = to_pci_dev(dev);
+       int ret;
+
+       pci_restore_state(pdev);
+       pci_set_power_state(pdev, PCI_D0);
+
+       ret = pci_enable_device(pdev);
+       if (ret)
+               return ret;
+
+       pci_set_master(pdev);
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(stmmac_pci_plat_resume);
+
+MODULE_DESCRIPTION("STMMAC PCI helper library");
+MODULE_AUTHOR("Yao Zi <ziyao@disroot.org>");
+MODULE_LICENSE("GPL");

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_libpci.h b/drivers/net/ethernet/stmicro/stmmac/stmmac_libpci.h
new file mode 100644 (file)
index 0000000..7155318
--- /dev/null
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_libpci.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2025 Yao Zi <ziyao@disroot.org>
+ */
+
+#ifndef __STMMAC_LIBPCI_H__
+#define __STMMAC_LIBPCI_H__
+
+int stmmac_pci_plat_suspend(struct device *dev, void *bsp_priv);
+int stmmac_pci_plat_resume(struct device *dev, void *bsp_priv);
+
+#endif /* __STMMAC_LIBPCI_H__ */