From ae0d7cbc99890b3a417a5705763784b8551a10d6 Mon Sep 17 00:00:00 2001 From: Paul Burton Date: Mon, 2 Dec 2013 16:48:37 +0000 Subject: [PATCH] MIPS: Malta: mux & enable SERIRQ interrupt This patch causes the kernel to mux the SERIRQ interrupt to the SERIRQ pin of the PIIX4 and to enable that interrupt. The kernel depends upon the interrupt when using the SuperIO UARTs (ttyS0 & ttyS1) but previously would not configure it, instead relying upon the bootloader having done so. If that is not the case then the typical result is that the system appears to hang once it reaches userland as no output is displayed on the UART. Signed-off-by: Paul Burton Reviewed-by: Markos Chandras Signed-off-by: John Crispin Patchwork: http://patchwork.linux-mips.org/patch/6182/ --- arch/mips/include/asm/mips-boards/piix4.h | 7 +++++++ arch/mips/pci/fixup-malta.c | 11 +++++++++++ 2 files changed, 18 insertions(+) diff --git a/arch/mips/include/asm/mips-boards/piix4.h b/arch/mips/include/asm/mips-boards/piix4.h index e33227998713..836e2ede24de 100644 --- a/arch/mips/include/asm/mips-boards/piix4.h +++ b/arch/mips/include/asm/mips-boards/piix4.h @@ -26,6 +26,10 @@ #define PIIX4_FUNC0_PIRQRC_IRQ_ROUTING_DISABLE (1 << 7) #define PIIX4_FUNC0_PIRQRC_IRQ_ROUTING_MASK 0xf #define PIIX4_FUNC0_PIRQRC_IRQ_ROUTING_MAX 16 +/* SERIRQ Control */ +#define PIIX4_FUNC0_SERIRQC 0x64 +#define PIIX4_FUNC0_SERIRQC_EN (1 << 7) +#define PIIX4_FUNC0_SERIRQC_CONT (1 << 6) /* Top Of Memory */ #define PIIX4_FUNC0_TOM 0x69 #define PIIX4_FUNC0_TOM_TOP_OF_MEMORY_MASK 0xf0 @@ -34,6 +38,9 @@ #define PIIX4_FUNC0_DLC_USBPR_EN (1 << 2) #define PIIX4_FUNC0_DLC_PASSIVE_RELEASE_EN (1 << 1) #define PIIX4_FUNC0_DLC_DELAYED_TRANSACTION_EN (1 << 0) +/* General Configuration */ +#define PIIX4_FUNC0_GENCFG 0xb0 +#define PIIX4_FUNC0_GENCFG_SERIRQ (1 << 16) /* IDE Timing */ #define PIIX4_FUNC1_IDETIM_PRIMARY_LO 0x40 diff --git a/arch/mips/pci/fixup-malta.c b/arch/mips/pci/fixup-malta.c index df36e2327c54..7a0eda782e35 100644 --- a/arch/mips/pci/fixup-malta.c +++ b/arch/mips/pci/fixup-malta.c @@ -54,6 +54,7 @@ int pcibios_plat_dev_init(struct pci_dev *dev) static void malta_piix_func0_fixup(struct pci_dev *pdev) { unsigned char reg_val; + u32 reg_val32; /* PIIX PIRQC[A:D] irq mappings */ static int piixirqmap[PIIX4_FUNC0_PIRQRC_IRQ_ROUTING_MAX] = { 0, 0, 0, 3, @@ -83,6 +84,16 @@ static void malta_piix_func0_fixup(struct pci_dev *pdev) pci_write_config_byte(pdev, PIIX4_FUNC0_TOM, reg_val | PIIX4_FUNC0_TOM_TOP_OF_MEMORY_MASK); } + + /* Mux SERIRQ to its pin */ + pci_read_config_dword(pdev, PIIX4_FUNC0_GENCFG, ®_val32); + pci_write_config_dword(pdev, PIIX4_FUNC0_GENCFG, + reg_val32 | PIIX4_FUNC0_GENCFG_SERIRQ); + + /* Enable SERIRQ */ + pci_read_config_byte(pdev, PIIX4_FUNC0_SERIRQC, ®_val); + reg_val |= PIIX4_FUNC0_SERIRQC_EN | PIIX4_FUNC0_SERIRQC_CONT; + pci_write_config_byte(pdev, PIIX4_FUNC0_SERIRQC, reg_val); } DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82371AB_0, -- 2.39.5