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From: robherring2@gmail.com (Rob Herring)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 3/9] ARM: versatile: add DT based PCI detection
Date: Tue, 30 Dec 2014 13:28:32 -0600	[thread overview]
Message-ID: <1419967718-26909-4-git-send-email-robherring2@gmail.com> (raw)
In-Reply-To: <1419967718-26909-1-git-send-email-robherring2@gmail.com>

From: Rob Herring <robh@kernel.org>

Disable the Versatile PCI DT node when no PCI backplane is detected. This
will prevent the Versatile PCI driver from probing when PCI is not
populated.

Signed-off-by: Rob Herring <robh@kernel.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Linus Walleij <linus.walleij@linaro.org>
---
 arch/arm/mach-versatile/versatile_dt.c | 46 ++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/arch/arm/mach-versatile/versatile_dt.c b/arch/arm/mach-versatile/versatile_dt.c
index 9f9bc61..5053810 100644
--- a/arch/arm/mach-versatile/versatile_dt.c
+++ b/arch/arm/mach-versatile/versatile_dt.c
@@ -22,15 +22,61 @@
  */
 
 #include <linux/init.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
 #include <linux/of_irq.h>
 #include <linux/of_platform.h>
+#include <linux/slab.h>
 #include <asm/mach-types.h>
 #include <asm/mach/arch.h>
 
 #include "core.h"
 
+#define VERSATILE_SYS_PCICTL_OFFSET           0x44
+
+static void __init versatile_dt_pci_init(void)
+{
+	u32 val;
+	void __iomem *base;
+	struct device_node *np;
+	struct property *newprop;
+
+	np = of_find_compatible_node(NULL, NULL, "arm,core-module-versatile");
+	if (!np)
+		return;
+
+	base = of_iomap(np, 0);
+	if (!base)
+		return;
+
+	/* Check if PCI backplane is detected */
+	val = __raw_readl(base + VERSATILE_SYS_PCICTL_OFFSET);
+	if (val & 1)
+		goto err;
+
+	np = of_find_compatible_node(NULL, NULL, "arm,versatile-pci");
+	if (!np)
+		goto err;
+
+	newprop = kzalloc(sizeof(*newprop), GFP_KERNEL);
+	if (!newprop)
+		goto err;
+
+	newprop->name = kstrdup("status", GFP_KERNEL);
+	newprop->value = kstrdup("disabled", GFP_KERNEL);
+	newprop->length = sizeof("disabled");
+	of_update_property(np, newprop);
+
+	pr_info("Not plugged into PCI backplane!\n");
+err:
+	iounmap(base);
+}
+
 static void __init versatile_dt_init(void)
 {
+	versatile_dt_pci_init();
+
 	of_platform_populate(NULL, of_default_bus_match_table,
 			     versatile_auxdata_lookup, NULL);
 }
-- 
2.1.0

  parent reply	other threads:[~2014-12-30 19:28 UTC|newest]

Thread overview: 43+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-12-30 19:28 [PATCH 0/9] ARM Versatile multi-platform support Rob Herring
2014-12-30 19:28 ` [PATCH 1/9] dt/bindings: add versatile PCI binding Rob Herring
2014-12-30 19:28 ` [PATCH 2/9] dts: versatile: add PCI controller binding Rob Herring
2014-12-30 19:28 ` Rob Herring [this message]
2014-12-30 21:37   ` [PATCH 3/9] ARM: versatile: add DT based PCI detection Arnd Bergmann
2014-12-30 23:05     ` Rob Herring
2014-12-31 15:23       ` Arnd Bergmann
2014-12-31 16:13         ` Peter Maydell
2014-12-31 19:22           ` Rob Herring
2014-12-31 21:07             ` Peter Maydell
2015-01-01 15:35               ` Arnd Bergmann
2015-01-01 15:52                 ` Peter Maydell
2015-01-08 19:37   ` Linus Walleij
2015-01-08 21:34     ` Rob Herring
2014-12-30 19:28 ` [PATCH 4/9] pci: add DT based ARM Versatile PCI host driver Rob Herring
2014-12-30 21:58   ` Arnd Bergmann
2015-01-02 18:14     ` Rob Herring
2015-01-02 20:52       ` Arnd Bergmann
2015-01-02 23:13         ` Rob Herring
2015-01-05  9:35           ` Arnd Bergmann
2015-01-24  1:01     ` Bjorn Helgaas
2015-01-24  0:54   ` Bjorn Helgaas
2014-12-30 19:28 ` [PATCH 5/9] dts: versatile: add sysregs nodes Rob Herring
2015-01-08 19:44   ` Linus Walleij
2015-01-08 23:53     ` Rob Herring
2015-01-09  7:10       ` Linus Walleij
2015-01-09 11:53         ` Lorenzo Pieralisi
2015-01-15 16:06       ` Lorenzo Pieralisi
2015-01-19 10:25         ` Linus Walleij
2014-12-30 19:28 ` [PATCH 6/9] ARM: versatile: switch to DT only booting and remove legacy code Rob Herring
2014-12-30 19:28 ` [PATCH 7/9] ARM: versatile: move mach includes into mach directory Rob Herring
2014-12-30 22:05   ` Arnd Bergmann
2014-12-30 19:28 ` [PATCH 8/9] ARM: versatile: convert to multi-platform Rob Herring
2014-12-30 19:28 ` [PATCH 9/9] ARM: versatile: consolidate code to single file Rob Herring
2014-12-30 22:08 ` [PATCH 0/9] ARM Versatile multi-platform support Arnd Bergmann
2014-12-31  9:25 ` Peter Maydell
2015-01-05  9:50   ` Marc Zyngier
2015-01-05 10:08     ` Peter Maydell
2015-01-05 11:19       ` Marc Zyngier
2015-01-05 17:41         ` Peter Maydell
2015-01-08 19:47 ` Linus Walleij
2015-01-08 21:38   ` Rob Herring
2015-01-09  8:34     ` Linus Walleij

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