i.MX31: Add support for the CPLD on PDK Debug board.

The i.MX31 PDK consists of several boards, one of them is a debug
board containing a CPLD which controls some debug leds, switch
buttons, an interrupt chip and an Ethernet controller.
This patch adds support for detecting if the PDK board is present
(during boot) and adds the interrupt chip to the kernel.

Signed-off-by: Magnus Lilja <lilja.magnus@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 148 insertions, 2 deletions

diff --git a/arch/arm/mach-mx3/mx31pdk.c b/arch/arm/mach-mx3/mx31pdk.c
index 5345498aeff3..32599e507534 100644
--- a/arch/arm/mach-mx3/mx31pdk.c
+++ b/arch/arm/mach-mx3/mx31pdk.c
@@ -20,6 +20,7 @@
 #include <linux/init.h>
 #include <linux/clk.h>
 #include <linux/irq.h>
+#include <linux/gpio.h>
 
 #include <mach/hardware.h>
 #include <asm/mach-types.h>
@@ -46,13 +47,156 @@ static int mx31pdk_pins[] = {
         MX31_PIN_CTS1__CTS1,
         MX31_PIN_RTS1__RTS1,
         MX31_PIN_TXD1__TXD1,
-        MX31_PIN_RXD1__RXD1
+        MX31_PIN_RXD1__RXD1,
+        IOMUX_MODE(MX31_PIN_GPIO1_1, IOMUX_CONFIG_GPIO),
 };
 
 static struct imxuart_platform_data uart_pdata = {
         .flags = IMXUART_HAVE_RTSCTS,
 };
 
+/*
+ * Routines for the CPLD on the debug board. It contains a CPLD handling
+ * LEDs, switches, interrupts for Ethernet.
+ */
+
+static void mx31pdk_expio_irq_handler(uint32_t irq, struct irq_desc *desc)
+{
+        uint32_t imr_val;
+        uint32_t int_valid;
+        uint32_t expio_irq;
+
+        imr_val = __raw_readw(CPLD_INT_MASK_REG);
+        int_valid = __raw_readw(CPLD_INT_STATUS_REG) & ~imr_val;
+
+        expio_irq = MXC_EXP_IO_BASE;
+        for (; int_valid != 0; int_valid >>= 1, expio_irq++) {
+                if ((int_valid & 1) == 0)
+                        continue;
+                generic_handle_irq(expio_irq);
+        }
+}
+
+/*
+ * Disable an expio pin's interrupt by setting the bit in the imr.
+ * @param irq           an expio virtual irq number
+ */
+static void expio_mask_irq(uint32_t irq)
+{
+        uint16_t reg;
+        uint32_t expio = MXC_IRQ_TO_EXPIO(irq);
+
+        /* mask the interrupt */
+        reg = __raw_readw(CPLD_INT_MASK_REG);
+        reg |= 1 << expio;
+        __raw_writew(reg, CPLD_INT_MASK_REG);
+}
+
+/*
+ * Acknowledge an expanded io pin's interrupt by clearing the bit in the isr.
+ * @param irq           an expanded io virtual irq number
+ */
+static void expio_ack_irq(uint32_t irq)
+{
+        uint32_t expio = MXC_IRQ_TO_EXPIO(irq);
+
+        /* clear the interrupt status */
+        __raw_writew(1 << expio, CPLD_INT_RESET_REG);
+        __raw_writew(0, CPLD_INT_RESET_REG);
+        /* mask the interrupt */
+        expio_mask_irq(irq);
+}
+
+/*
+ * Enable a expio pin's interrupt by clearing the bit in the imr.
+ * @param irq           a expio virtual irq number
+ */
+static void expio_unmask_irq(uint32_t irq)
+{
+        uint16_t reg;
+        uint32_t expio = MXC_IRQ_TO_EXPIO(irq);
+
+        /* unmask the interrupt */
+        reg = __raw_readw(CPLD_INT_MASK_REG);
+        reg &= ~(1 << expio);
+        __raw_writew(reg, CPLD_INT_MASK_REG);
+}
+
+static struct irq_chip expio_irq_chip = {
+        .ack = expio_ack_irq,
+        .mask = expio_mask_irq,
+        .unmask = expio_unmask_irq,
+};
+
+static int __init mx31pdk_init_expio(void)
+{
+        int i;
+        int ret;
+
+        /* Check if there's a debug board connected */
+        if ((__raw_readw(CPLD_MAGIC_NUMBER1_REG) != 0xAAAA) ||
+            (__raw_readw(CPLD_MAGIC_NUMBER2_REG) != 0x5555) ||
+            (__raw_readw(CPLD_MAGIC_NUMBER3_REG) != 0xCAFE)) {
+                /* No Debug board found */
+                return -ENODEV;
+        }
+
+        pr_info("i.MX31PDK Debug board detected, rev = 0x%04X\n",
+                __raw_readw(CPLD_CODE_VER_REG));
+
+        /*
+         * Configure INT line as GPIO input
+         */
+        ret = gpio_request(IOMUX_TO_GPIO(MX31_PIN_GPIO1_1), "sms9217-irq");
+        if (ret)
+                pr_warning("could not get LAN irq gpio\n");
+        else
+                gpio_direction_input(IOMUX_TO_GPIO(MX31_PIN_GPIO1_1));
+
+        /* Disable the interrupts and clear the status */
+        __raw_writew(0, CPLD_INT_MASK_REG);
+        __raw_writew(0xFFFF, CPLD_INT_RESET_REG);
+        __raw_writew(0, CPLD_INT_RESET_REG);
+        __raw_writew(0x1F, CPLD_INT_MASK_REG);
+        for (i = MXC_EXP_IO_BASE;
+             i < (MXC_EXP_IO_BASE + MXC_MAX_EXP_IO_LINES);
+             i++) {
+                set_irq_chip(i, &expio_irq_chip);
+                set_irq_handler(i, handle_level_irq);
+                set_irq_flags(i, IRQF_VALID);
+        }
+        set_irq_type(EXPIO_PARENT_INT, IRQ_TYPE_LEVEL_LOW);
+        set_irq_chained_handler(EXPIO_PARENT_INT, mx31pdk_expio_irq_handler);
+
+        return 0;
+}
+
+/*
+ * This structure defines the MX31 memory map.
+ */
+static struct map_desc mx31pdk_io_desc[] __initdata = {
+        {
+                .virtual = SPBA0_BASE_ADDR_VIRT,
+                .pfn = __phys_to_pfn(SPBA0_BASE_ADDR),
+                .length = SPBA0_SIZE,
+                .type = MT_DEVICE_NONSHARED,
+        }, {
+                .virtual = CS5_BASE_ADDR_VIRT,
+                .pfn = __phys_to_pfn(CS5_BASE_ADDR),
+                .length = CS5_SIZE,
+                .type = MT_DEVICE,
+        },
+};
+
+/*
+ * Set up static virtual mappings.
+ */
+static void __init mx31pdk_map_io(void)
+{
+        mx31_map_io();
+        iotable_init(mx31pdk_io_desc, ARRAY_SIZE(mx31pdk_io_desc));
+}
+
 /*!
  * Board specific initialization.
  */
@@ -62,6 +206,8 @@ static void __init mxc_board_init(void)
                                       "mx31pdk");
 
         mxc_register_device(&mxc_uart_device0, &uart_pdata);
+
+        mx31pdk_init_expio();
 }
 
 static void __init mx31pdk_timer_init(void)
@@ -82,7 +228,7 @@ MACHINE_START(MX31_3DS, "Freescale MX31PDK (3DS)")
         .phys_io        = AIPS1_BASE_ADDR,
         .io_pg_offst    = ((AIPS1_BASE_ADDR_VIRT) >> 18) & 0xfffc,
         .boot_params    = PHYS_OFFSET + 0x100,
-        .map_io         = mx31_map_io,
+        .map_io         = mx31pdk_map_io,
         .init_irq       = mxc_init_irq,
         .init_machine   = mxc_board_init,
         .timer          = &mx31pdk_timer,