[PATCH] orion/kirkwood: reset PCIe unit on boot

[Olaf Rempel]

Patch found in QNAPs vendor source package, with some cleanups
(proper defines, shortened max. timeout from 1s to 200ms).

Without this patch the PCIe SATA controller (Marvell 88sx7042/sata_mv)
in my QNAP TS-419P (Marvell 88f6281/Kirkwood) stops working after a
few minutes.
The symptomes are described in this thread:
http://marc.info/?l=linux-ide&m=124822863706181&w=2
---
 arch/arm/plat-orion/pcie.c |   34 ++++++++++++++++++++++++++++++++++
 1 files changed, 34 insertions(+), 0 deletions(-)

diff --git a/arch/arm/plat-orion/pcie.c b/arch/arm/plat-orion/pcie.c
index 54c84a4..779553a 100644
--- a/arch/arm/plat-orion/pcie.c
+++ b/arch/arm/plat-orion/pcie.c
@@ -13,6 +13,7 @@
 #include <linux/mbus.h>
 #include <asm/mach/pci.h>
 #include <plat/pcie.h>
+#include <linux/delay.h>
 
 /*
  * PCIe unit register offsets.
@@ -46,6 +47,8 @@
 #define  PCIE_STAT_BUS_OFFS		8
 #define  PCIE_STAT_BUS_MASK		0xff
 #define  PCIE_STAT_LINK_DOWN		1
+#define PCIE_DEBUG_CTRL         0x1a60
+#define  PCIE_DEBUG_SOFT_RESET		(1<<20)
 
 
 u32 __init orion_pcie_dev_id(void __iomem *base)
@@ -85,6 +88,32 @@ void __init orion_pcie_set_local_bus_nr(void __iomem *base, int nr)
 	writel(stat, base + PCIE_STAT_OFF);
 }
 
+void __init orion_pcie_reset(void __iomem *base)
+{
+	u32 reg;
+	int i;
+
+	/*
+	 * MV-S104860-U0, Rev. C:
+	 * PCI Express Unit Soft Reset
+	 * When set, generates an internal reset in the PCI Express unit.
+	 * This bit should be cleared after the link is re-established.
+	 */
+	reg = readl(base + PCIE_DEBUG_CTRL);
+	reg |= PCIE_DEBUG_SOFT_RESET;
+	writel(reg, base + PCIE_DEBUG_CTRL);
+
+	for (i = 0; i < 20; i++) {
+		mdelay(10);
+
+		if (orion_pcie_link_up(base))
+			break;
+	}
+
+	reg &= ~(PCIE_DEBUG_SOFT_RESET);
+	writel(reg, base + PCIE_DEBUG_CTRL);
+}
+
 /*
  * Setup PCIE BARs and Address Decode Wins:
  * BAR[0,2] -> disabled, BAR[1] -> covers all DRAM banks
@@ -153,6 +182,11 @@ void __init orion_pcie_setup(void __iomem *base,
 	u32 mask;
 
 	/*
+	 * soft reset PCIe unit
+	 */
+	orion_pcie_reset(base);
+
+	/*
 	 * Point PCIe unit MBUS decode windows to DRAM space.
 	 */
 	orion_pcie_setup_wins(base, dram);
-- 
1.6.3.3