MIPS: ath79: Improve the DDR controller interface

The DDR controller need to be used by the IRQ controller to flush
the write buffer of some devices before running the IRQ handler.
It is also used by the PCI controller to setup the PCI memory windows.

The current interface used to access the DDR controller doesn't
provides any useful abstraction and simply rely on a shared global
pointer.

Replace this by a simple API to setup the PCI memory windows and use
the write buffer flush independently of the SoC type. That remove the
need for the shared global pointer, simplify the IRQ handler code.

[ralf@linux-mips.org: Folded in Alban Bedel's follup fix.]

Signed-off-by: Alban Bedel <albeu@free.fr>
Cc: linux-mips@linux-mips.org
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: Qais Yousef <qais.yousef@imgtec.com>
Cc: Wolfram Sang <wsa@the-dreams.de>
Cc: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Cc: Gabor Juhos <juhosg@openwrt.org>
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/9773/
Patchwork: http://patchwork.linux-mips.org/patch/10543/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 33 insertions, 2 deletions

diff --git a/arch/mips/ath79/common.c b/arch/mips/ath79/common.c
index eb3966cd8cfc..3cedd1f95e0f 100644
--- a/arch/mips/ath79/common.c
+++ b/arch/mips/ath79/common.c
@@ -38,11 +38,27 @@ unsigned int ath79_soc_rev;
 void __iomem *ath79_pll_base;
 void __iomem *ath79_reset_base;
 EXPORT_SYMBOL_GPL(ath79_reset_base);
-void __iomem *ath79_ddr_base;
+static void __iomem *ath79_ddr_base;
+static void __iomem *ath79_ddr_wb_flush_base;
+static void __iomem *ath79_ddr_pci_win_base;
+
+void ath79_ddr_ctrl_init(void)
+{
+	ath79_ddr_base = ioremap_nocache(AR71XX_DDR_CTRL_BASE,
+					 AR71XX_DDR_CTRL_SIZE);
+	if (soc_is_ar71xx() || soc_is_ar934x()) {
+		ath79_ddr_wb_flush_base = ath79_ddr_base + 0x9c;
+		ath79_ddr_pci_win_base = ath79_ddr_base + 0x7c;
+	} else {
+		ath79_ddr_wb_flush_base = ath79_ddr_base + 0x7c;
+		ath79_ddr_pci_win_base = 0;
+	}
+}
+EXPORT_SYMBOL_GPL(ath79_ddr_ctrl_init);
 
 void ath79_ddr_wb_flush(u32 reg)
 {
-	void __iomem *flush_reg = ath79_ddr_base + reg;
+	void __iomem *flush_reg = ath79_ddr_wb_flush_base + reg;
 
 	/* Flush the DDR write buffer. */
 	__raw_writel(0x1, flush_reg);
@@ -56,6 +72,21 @@ void ath79_ddr_wb_flush(u32 reg)
 }
 EXPORT_SYMBOL_GPL(ath79_ddr_wb_flush);
 
+void ath79_ddr_set_pci_windows(void)
+{
+	BUG_ON(!ath79_ddr_pci_win_base);
+
+	__raw_writel(AR71XX_PCI_WIN0_OFFS, ath79_ddr_pci_win_base + 0);
+	__raw_writel(AR71XX_PCI_WIN1_OFFS, ath79_ddr_pci_win_base + 1);
+	__raw_writel(AR71XX_PCI_WIN2_OFFS, ath79_ddr_pci_win_base + 2);
+	__raw_writel(AR71XX_PCI_WIN3_OFFS, ath79_ddr_pci_win_base + 3);
+	__raw_writel(AR71XX_PCI_WIN4_OFFS, ath79_ddr_pci_win_base + 4);
+	__raw_writel(AR71XX_PCI_WIN5_OFFS, ath79_ddr_pci_win_base + 5);
+	__raw_writel(AR71XX_PCI_WIN6_OFFS, ath79_ddr_pci_win_base + 6);
+	__raw_writel(AR71XX_PCI_WIN7_OFFS, ath79_ddr_pci_win_base + 7);
+}
+EXPORT_SYMBOL_GPL(ath79_ddr_set_pci_windows);
+
 void ath79_device_reset_set(u32 mask)
 {
 	unsigned long flags;