EDAC, mpc85xx: Make mpc85xx-pci-edac a platform device

Originally the mpc85xx-pci-edac driver bound directly to the PCI
controller node.

Commit

905e75c46dba ("powerpc/fsl-pci: Unify pci/pcie initialization code")

turned the PCI controller code into a platform device. Since we can't
have two drivers binding to the same device, the EDAC code was changed
to be called into as a library-style submodule. However, this doesn't
work if the EDAC driver is built as a module.

Commit

8d8fcba6d1ea ("EDAC: Rip out the edac_subsys reference counting")

exposed another problem with this approach -- mpc85xx_pci_err_probe()
was being called in the same early boot phase that the PCI controller
is initialized, rather than in the device_initcall phase that the EDAC
layer expects. This caused a crash on boot.

To fix this, the PCI controller code now creates a child platform device
specifically for EDAC, which the mpc85xx-pci-edac driver binds to.

Reported-by: Michael Ellerman <[e-mail]>
Reviewed-by: Johannes Thumshirn <[e-mail]>
Signed-off-by: Scott Wood <[e-mail]>
Cc: Andrew Morton <[e-mail]>
Cc: Benjamin Herrenschmidt <[e-mail]>
Cc: Daniel Axtens <[e-mail]>
Cc: Doug Thompson <[e-mail]>
Cc: Jia Hongtao <[e-mail]>
Cc: Jiri Kosina <[e-mail]>
Cc: Kim Phillips <[e-mail]>
Cc: linux-edac <[e-mail]>
Cc: [e-mail]
Cc: Masanari Iida <[e-mail]>
Cc: Mauro Carvalho Chehab <[e-mail]>
Cc: Paul Mackerras <[e-mail]>
Cc: Randy Dunlap <[e-mail]>
Cc: Rob Herring <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Borislav Petkov <[e-mail]>

arch/powerpc/sysdev/fsl_pci.c

···
 #include <linux/pci.h>
 #include <linux/delay.h>
 #include <linux/string.h>
+#include <linux/fsl/edac.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/memblock.h>
 #include <linux/log2.h>
+#include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/suspend.h>
 #include <linux/syscore_ops.h>
···
 #endif
 }
 
+static int add_err_dev(struct platform_device *pdev)
+{
+	struct platform_device *errdev;
+	struct mpc85xx_edac_pci_plat_data pd = {
+		.of_node = pdev->dev.of_node
+	};
+
+	errdev = platform_device_register_resndata(&pdev->dev,
+						   "mpc85xx-pci-edac",
+						   PLATFORM_DEVID_AUTO,
+						   pdev->resource,
+						   pdev->num_resources,
+						   &pd, sizeof(pd));
+	if (IS_ERR(errdev))
+		return PTR_ERR(errdev);
+
+	return 0;
+}
+
 static int fsl_pci_probe(struct platform_device *pdev)
 {
 	struct device_node *node;
···
 
 	node = pdev->dev.of_node;
 	ret = fsl_add_bridge(pdev, fsl_pci_primary == node);
+	if (ret)
+		return ret;
 
-	mpc85xx_pci_err_probe(pdev);
+	ret = add_err_dev(pdev);
+	if (ret)
+		dev_err(&pdev->dev, "couldn't register error device: %d\n",
+			ret);
 
 	return 0;
 }

arch/powerpc/sysdev/fsl_pci.h

···
 static inline void fsl_pci_assign_primary(void) {}
 #endif
 
-#ifdef CONFIG_EDAC_MPC85XX
-int mpc85xx_pci_err_probe(struct platform_device *op);
-#else
-static inline int mpc85xx_pci_err_probe(struct platform_device *op)
-{
-	return -ENOTSUPP;
-}
-#endif
-
 #ifdef CONFIG_FSL_PCI
 extern int fsl_pci_mcheck_exception(struct pt_regs *);
 #else

drivers/edac/mpc85xx_edac.c

···
 #include <linux/edac.h>
 #include <linux/smp.h>
 #include <linux/gfp.h>
+#include <linux/fsl/edac.h>
 
 #include <linux/of_platform.h>
 #include <linux/of_device.h>
···
 	return IRQ_HANDLED;
 }
 
-int mpc85xx_pci_err_probe(struct platform_device *op)
+static int mpc85xx_pci_err_probe(struct platform_device *op)
 {
 	struct edac_pci_ctl_info *pci;
 	struct mpc85xx_pci_pdata *pdata;
+	struct mpc85xx_edac_pci_plat_data *plat_data;
+	struct device_node *of_node;
 	struct resource r;
 	int res = 0;
 
···
 	pdata->name = "mpc85xx_pci_err";
 	pdata->irq = NO_IRQ;
 
-	if (mpc85xx_pcie_find_capability(op->dev.of_node) > 0)
+	plat_data = op->dev.platform_data;
+	if (!plat_data) {
+		dev_err(&op->dev, "no platform data");
+		res = -ENXIO;
+		goto err;
+	}
+	of_node = plat_data->of_node;
+
+	if (mpc85xx_pcie_find_capability(of_node) > 0)
 		pdata->is_pcie = true;
 
 	dev_set_drvdata(&op->dev, pci);
···
 
 	pdata->edac_idx = edac_pci_idx++;
 
-	res = of_address_to_resource(op->dev.of_node, 0, &r);
+	res = of_address_to_resource(of_node, 0, &r);
 	if (res) {
 		printk(KERN_ERR "%s: Unable to get resource for "
 		       "PCI err regs\n", __func__);
···
 	}
 
 	if (edac_op_state == EDAC_OPSTATE_INT) {
-		pdata->irq = irq_of_parse_and_map(op->dev.of_node, 0);
+		pdata->irq = irq_of_parse_and_map(of_node, 0);
 		res = devm_request_irq(&op->dev, pdata->irq,
 				       mpc85xx_pci_isr,
 				       IRQF_SHARED,
···
 	devres_release_group(&op->dev, mpc85xx_pci_err_probe);
 	return res;
 }
-EXPORT_SYMBOL(mpc85xx_pci_err_probe);
 
+static const struct platform_device_id mpc85xx_pci_err_match[] = {
+	{
+		.name = "mpc85xx-pci-edac"
+	},
+	{}
+};
+
+static struct platform_driver mpc85xx_pci_err_driver = {
+	.probe = mpc85xx_pci_err_probe,
+	.id_table = mpc85xx_pci_err_match,
+	.driver = {
+		.name = "mpc85xx_pci_err",
+		.suppress_bind_attrs = true,
+	},
+};
 #endif				/* CONFIG_PCI */
 
 /**************************** L2 Err device ***************************/
···
 static struct platform_driver * const drivers[] = {
 	&mpc85xx_mc_err_driver,
 	&mpc85xx_l2_err_driver,
+#ifdef CONFIG_PCI
+	&mpc85xx_pci_err_driver,
+#endif
 };
 
 static int __init mpc85xx_mc_init(void)

include/linux/fsl/edac.h

···
+#ifndef FSL_EDAC_H
+#define FSL_EDAC_H
+
+struct mpc85xx_edac_pci_plat_data {
+	struct device_node *of_node;
+};
+
+#endif