diff options
Diffstat (limited to 'arch/arc/plat-hsdk/platform.c')
| -rw-r--r-- | arch/arc/plat-hsdk/platform.c | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/arch/arc/plat-hsdk/platform.c b/arch/arc/plat-hsdk/platform.c index 2958aedb649a..2588b842407c 100644 --- a/arch/arc/plat-hsdk/platform.c +++ b/arch/arc/plat-hsdk/platform.c @@ -42,6 +42,66 @@ static void __init hsdk_init_per_cpu(unsigned int cpu) #define SDIO_UHS_REG_EXT (SDIO_BASE + 0x108) #define SDIO_UHS_REG_EXT_DIV_2 (2 << 30) +#define HSDK_GPIO_INTC (ARC_PERIPHERAL_BASE + 0x3000) + +static void __init hsdk_enable_gpio_intc_wire(void) +{ + /* + * Peripherals on CPU Card are wired to cpu intc via intermediate + * DW APB GPIO blocks (mainly for debouncing) + * + * --------------------- + * | snps,archs-intc | + * --------------------- + * | + * ---------------------- + * | snps,archs-idu-intc | + * ---------------------- + * | | | | | + * | [eth] [USB] [... other peripherals] + * | + * ------------------- + * | snps,dw-apb-intc | + * ------------------- + * | | | | + * [Bt] [HAPS] [... other peripherals] + * + * Current implementation of "irq-dw-apb-ictl" driver doesn't work well + * with stacked INTCs. In particular problem happens if its master INTC + * not yet instantiated. See discussion here - + * https://lkml.org/lkml/2015/3/4/755 + * + * So setup the first gpio block as a passive pass thru and hide it from + * DT hardware topology - connect intc directly to cpu intc + * The GPIO "wire" needs to be init nevertheless (here) + * + * One side adv is that peripheral interrupt handling avoids one nested + * intc ISR hop + * + * According to HSDK User's Manual [1], "Table 2 Interrupt Mapping" + * we have the following GPIO input lines used as sources of interrupt: + * - GPIO[0] - Bluetooth interrupt of RS9113 module + * - GPIO[2] - HAPS interrupt (on HapsTrak 3 connector) + * - GPIO[3] - Audio codec (MAX9880A) interrupt + * - GPIO[8-23] - Available on Arduino and PMOD_x headers + * For now there's no use of Arduino and PMOD_x headers in Linux + * use-case so we only enable lines 0, 2 and 3. + * + * [1] https://github.com/foss-for-synopsys-dwc-arc-processors/ARC-Development-Systems-Forum/wiki/docs/ARC_HSDK_User_Guide.pdf + */ +#define GPIO_INTEN (HSDK_GPIO_INTC + 0x30) +#define GPIO_INTMASK (HSDK_GPIO_INTC + 0x34) +#define GPIO_INTTYPE_LEVEL (HSDK_GPIO_INTC + 0x38) +#define GPIO_INT_POLARITY (HSDK_GPIO_INTC + 0x3c) +#define GPIO_INT_CONNECTED_MASK 0x0d + + iowrite32(0xffffffff, (void __iomem *) GPIO_INTMASK); + iowrite32(~GPIO_INT_CONNECTED_MASK, (void __iomem *) GPIO_INTMASK); + iowrite32(0x00000000, (void __iomem *) GPIO_INTTYPE_LEVEL); + iowrite32(0xffffffff, (void __iomem *) GPIO_INT_POLARITY); + iowrite32(GPIO_INT_CONNECTED_MASK, (void __iomem *) GPIO_INTEN); +} + static void __init hsdk_init_early(void) { /* @@ -62,6 +122,8 @@ static void __init hsdk_init_early(void) * minimum possible div-by-2. */ iowrite32(SDIO_UHS_REG_EXT_DIV_2, (void __iomem *) SDIO_UHS_REG_EXT); + + hsdk_enable_gpio_intc_wire(); } static const char *hsdk_compat[] __initconst = { |