[RFC PATCH v8 7/7] PCI / PM: Add support for the PCIe WAKE# signal for OF

From: Jeffy Chen
Date: Thu Oct 26 2017 - 09:29:53 EST


Add pci-of.c to handle the PCIe WAKE# interrupt.

Also use the dedicated wakeirq infrastructure to simplify it.

Signed-off-by: Jeffy Chen <jeffy.chen@xxxxxxxxxxxxxx>
---

Changes in v8:
Add pci-of.c and use platform_pm_ops to handle the PCIe WAKE# signal.

Changes in v7:
Move PCIE_WAKE handling into pci core.

Changes in v6:
Fix device_init_wake error handling, and add some comments.

Changes in v5:
Rebase.

Changes in v3:
Fix error handling.

Changes in v2:
Use dev_pm_set_dedicated_wake_irq.

drivers/pci/Makefile | 2 +-
drivers/pci/pci-of.c | 136 +++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 137 insertions(+), 1 deletion(-)
create mode 100644 drivers/pci/pci-of.c

diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile
index 66a21acad952..4f76dbdb024c 100644
--- a/drivers/pci/Makefile
+++ b/drivers/pci/Makefile
@@ -49,7 +49,7 @@ obj-$(CONFIG_PCI_ECAM) += ecam.o

obj-$(CONFIG_XEN_PCIDEV_FRONTEND) += xen-pcifront.o

-obj-$(CONFIG_OF) += of.o
+obj-$(CONFIG_OF) += of.o pci-of.o

ccflags-$(CONFIG_PCI_DEBUG) := -DDEBUG

diff --git a/drivers/pci/pci-of.c b/drivers/pci/pci-of.c
new file mode 100644
index 000000000000..55a33206fc84
--- /dev/null
+++ b/drivers/pci/pci-of.c
@@ -0,0 +1,136 @@
+/*
+ * OF PCI PM support
+ *
+ * Copyright (c) 2017 Rockchip, Inc.
+ *
+ * Author: Jeffy Chen <jeffy.chen@xxxxxxxxxxxxxx>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/init.h>
+#include <linux/of_irq.h>
+#include <linux/pci.h>
+#include <linux/pm_wakeirq.h>
+#include "pci.h"
+
+struct of_pci_pm_data {
+ struct device *dev;
+ unsigned int wakeup_irq;
+ atomic_t wakeup_cnt;
+};
+
+static void *of_pci_setup(struct device *dev)
+{
+ struct of_pci_pm_data *data;
+ int irq;
+
+ if (!dev->of_node)
+ return NULL;
+
+ data = devm_kzalloc(dev, sizeof(struct of_pci_pm_data), GFP_KERNEL);
+ if (!data)
+ return ERR_PTR(-ENOMEM);
+
+ irq = of_irq_get_byname(dev->of_node, "wakeup");
+ if (irq < 0) {
+ if (irq == -EPROBE_DEFER)
+ return ERR_PTR(irq);
+
+ return NULL;
+ }
+
+ data->wakeup_irq = irq;
+ data->dev = dev;
+
+ device_init_wakeup(dev, false);
+
+ dev_info(dev, "Wakeup IRQ %d\n", irq);
+ return data;
+}
+
+static void *of_pci_setup_dev(struct pci_dev *pci_dev)
+{
+ return of_pci_setup(&pci_dev->dev);
+}
+
+static void *of_pci_setup_host_bridge(struct pci_host_bridge *bridge)
+{
+ return of_pci_setup(bridge->dev.parent);
+}
+
+static void of_pci_cleanup(void *pmdata)
+{
+ struct of_pci_pm_data *data = pmdata;
+
+ if (IS_ERR_OR_NULL(data)) {
+ device_init_wakeup(data->dev, false);
+ dev_pm_clear_wake_irq(data->dev);
+ }
+}
+
+static bool of_pci_can_wakeup(void *pmdata)
+{
+ struct of_pci_pm_data *data = pmdata;
+
+ if (IS_ERR_OR_NULL(data))
+ return false;
+
+ return data->wakeup_irq > 0;
+}
+
+static int of_pci_dev_wakeup(void *pmdata, bool enable)
+{
+ struct of_pci_pm_data *data = pmdata;
+ struct device *dev = data->dev;
+ int ret;
+
+ if (!enable) {
+ dev_pm_clear_wake_irq(dev);
+ return device_set_wakeup_enable(dev, false);
+ }
+
+ ret = device_set_wakeup_enable(dev, true);
+ if (ret < 0)
+ return ret;
+
+ ret = dev_pm_set_dedicated_wake_irq(dev, data->wakeup_irq);
+ if (ret < 0) {
+ device_set_wakeup_enable(dev, false);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int of_pci_bridge_wakeup(void *pmdata, bool enable)
+{
+ struct of_pci_pm_data *data = pmdata;
+
+ if (enable && atomic_inc_return(&data->wakeup_cnt) != 1)
+ return 0;
+
+ if (!enable && atomic_dec_return(&data->wakeup_cnt) != 0)
+ return 0;
+
+ return of_pci_dev_wakeup(pmdata, enable);
+}
+
+static const struct pci_platform_pm_ops of_pci_platform_pm = {
+ .setup_dev = of_pci_setup_dev,
+ .setup_host_bridge = of_pci_setup_host_bridge,
+ .cleanup = of_pci_cleanup,
+ .can_wakeup = of_pci_can_wakeup,
+ .dev_wakeup = of_pci_dev_wakeup,
+ .bridge_wakeup = of_pci_bridge_wakeup,
+};
+
+static int __init of_pci_init(void)
+{
+ pci_set_platform_pm(&of_pci_platform_pm);
+ return 0;
+}
+arch_initcall(of_pci_init);
--
2.11.0