Merge tag 'locks-v4.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton...

[sfrench/cifs-2.6.git] / arch / arc / plat-hsdk / platform.c

diff --git a/arch/arc/plat-hsdk/platform.c b/arch/arc/plat-hsdk/platform.c
index 2958aedb649ab183edcce1ca858006f67fd8ff21..2588b842407c281df0051b814fefd3cfcd9c31fe 100644 (file)
--- 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 = {