powerpc/5200: Refactor mpc5200 interrupt controller driver

Rework the mpc5200-pic driver to simplify it and fix up the setting
of desc->status when set_type is called for internal IRQs (so they
are reported as level, not edge).  The simplification is due to
splitting off the handling of external IRQs into a separate block
so they don't need to be handled as exceptions in the normal
CRIT, MAIN and PERP paths.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

diff --git a/arch/powerpc/platforms/52xx/mpc52xx_pic.c b/arch/powerpc/platforms/52xx/mpc52xx_pic.c
index c0a9559..480f806 100644 (file)
--- a/arch/powerpc/platforms/52xx/mpc52xx_pic.c
+++ b/arch/powerpc/platforms/52xx/mpc52xx_pic.c
@@ -190,10 +190,10 @@ static void mpc52xx_extirq_ack(unsigned int virq)
 
 static int mpc52xx_extirq_set_type(unsigned int virq, unsigned int flow_type)
 {
-       struct irq_desc *desc = get_irq_desc(virq);
        u32 ctrl_reg, type;
        int irq;
        int l2irq;
+       void *handler = handle_level_irq;
 
        irq = irq_map[virq].hwirq;
        l2irq = irq & MPC52xx_IRQ_L2_MASK;
@@ -201,32 +201,21 @@ static int mpc52xx_extirq_set_type(unsigned int virq, unsigned int flow_type)
        pr_debug("%s: irq=%x. l2=%d flow_type=%d\n", __func__, irq, l2irq, flow_type);
 
        switch (flow_type) {
-       case IRQF_TRIGGER_HIGH:
-               type = 0;
-               break;
-       case IRQF_TRIGGER_RISING:
-               type = 1;
-               break;
-       case IRQF_TRIGGER_FALLING:
-               type = 2;
-               break;
-       case IRQF_TRIGGER_LOW:
-               type = 3;
-               break;
+       case IRQF_TRIGGER_HIGH: type = 0; break;
+       case IRQF_TRIGGER_RISING: type = 1; handler = handle_edge_irq; break;
+       case IRQF_TRIGGER_FALLING: type = 2; handler = handle_edge_irq; break;
+       case IRQF_TRIGGER_LOW: type = 3; break;
        default:
                type = 0;
        }
 
-       desc->status &= ~(IRQ_TYPE_SENSE_MASK | IRQ_LEVEL);
-       desc->status |= flow_type & IRQ_TYPE_SENSE_MASK;
-       if (flow_type & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW))
-               desc->status |= IRQ_LEVEL;
-
        ctrl_reg = in_be32(&intr->ctrl);
        ctrl_reg &= ~(0x3 << (22 - (l2irq * 2)));
        ctrl_reg |= (type << (22 - (l2irq * 2)));
        out_be32(&intr->ctrl, ctrl_reg);
 
+       __set_irq_handler_unlocked(virq, handler);
+
        return 0;
 }
 
@@ -241,6 +230,11 @@ static struct irq_chip mpc52xx_extirq_irqchip = {
 /*
  * Main interrupt irq_chip
  */
+static int mpc52xx_null_set_type(unsigned int virq, unsigned int flow_type)
+{
+       return 0; /* Do nothing so that the sense mask will get updated */
+}
+
 static void mpc52xx_main_mask(unsigned int virq)
 {
        int irq;
@@ -268,6 +262,7 @@ static struct irq_chip mpc52xx_main_irqchip = {
        .mask = mpc52xx_main_mask,
        .mask_ack = mpc52xx_main_mask,
        .unmask = mpc52xx_main_unmask,
+       .set_type = mpc52xx_null_set_type,
 };
 
 /*
@@ -300,6 +295,7 @@ static struct irq_chip mpc52xx_periph_irqchip = {
        .mask = mpc52xx_periph_mask,
        .mask_ack = mpc52xx_periph_mask,
        .unmask = mpc52xx_periph_unmask,
+       .set_type = mpc52xx_null_set_type,
 };
 
 /*
@@ -343,8 +339,18 @@ static struct irq_chip mpc52xx_sdma_irqchip = {
        .mask = mpc52xx_sdma_mask,
        .unmask = mpc52xx_sdma_unmask,
        .ack = mpc52xx_sdma_ack,
+       .set_type = mpc52xx_null_set_type,
 };
 
+/**
+ * mpc52xx_is_extirq - Returns true if hwirq number is for an external IRQ
+ */
+static int mpc52xx_is_extirq(int l1, int l2)
+{
+       return ((l1 == 0) && (l2 == 0)) ||
+              ((l1 == 1) && (l2 >= 1) && (l2 <= 3));
+}
+
 /**
  * mpc52xx_irqhost_xlate - translate virq# from device tree interrupts property
  */
@@ -363,37 +369,22 @@ static int mpc52xx_irqhost_xlate(struct irq_host *h, struct device_node *ct,
 
        intrvect_l1 = (int)intspec[0];
        intrvect_l2 = (int)intspec[1];
-       intrvect_type = (int)intspec[2];
+       intrvect_type = (int)intspec[2] & 0x3;
 
        intrvect_linux = (intrvect_l1 << MPC52xx_IRQ_L1_OFFSET) &
                         MPC52xx_IRQ_L1_MASK;
        intrvect_linux |= intrvect_l2 & MPC52xx_IRQ_L2_MASK;
 
-       pr_debug("return %x, l1=%d, l2=%d\n", intrvect_linux, intrvect_l1,
-                intrvect_l2);
-
        *out_hwirq = intrvect_linux;
-       *out_flags = mpc52xx_map_senses[intrvect_type];
+       *out_flags = IRQ_TYPE_LEVEL_LOW;
+       if (mpc52xx_is_extirq(intrvect_l1, intrvect_l2))
+               *out_flags = mpc52xx_map_senses[intrvect_type];
 
+       pr_debug("return %x, l1=%d, l2=%d\n", intrvect_linux, intrvect_l1,
+                intrvect_l2);
        return 0;
 }
 
-/**
- * mpc52xx_irqx_gettype - determine the IRQ sense type (level/edge)
- *
- * Only external IRQs need this.
- */
-static int mpc52xx_irqx_gettype(int irq)
-{
-       int type;
-       u32 ctrl_reg;
-
-       ctrl_reg = in_be32(&intr->ctrl);
-       type = (ctrl_reg >> (22 - irq * 2)) & 0x3;
-
-       return mpc52xx_map_senses[type];
-}
-
 /**
  * mpc52xx_irqhost_map - Hook to map from virq to an irq_chip structure
  */
@@ -402,68 +393,46 @@ static int mpc52xx_irqhost_map(struct irq_host *h, unsigned int virq,
 {
        int l1irq;
        int l2irq;
-       struct irq_chip *good_irqchip;
-       void *good_handle;
+       struct irq_chip *irqchip;
+       void *hndlr;
        int type;
+       u32 reg;
 
        l1irq = (irq & MPC52xx_IRQ_L1_MASK) >> MPC52xx_IRQ_L1_OFFSET;
        l2irq = irq & MPC52xx_IRQ_L2_MASK;
 
        /*
-        * Most of ours IRQs will be level low
-        * Only external IRQs on some platform may be others
+        * External IRQs are handled differently by the hardware so they are
+        * handled by a dedicated irq_chip structure.
         */
-       type = IRQ_TYPE_LEVEL_LOW;
+       if (mpc52xx_is_extirq(l1irq, l2irq)) {
+               reg = in_be32(&intr->ctrl);
+               type = mpc52xx_map_senses[(reg >> (22 - l2irq * 2)) & 0x3];
+               if ((type == IRQ_TYPE_EDGE_FALLING) ||
+                   (type == IRQ_TYPE_EDGE_RISING))
+                       hndlr = handle_edge_irq;
+               else
+                       hndlr = handle_level_irq;
+
+               set_irq_chip_and_handler(virq, &mpc52xx_extirq_irqchip, hndlr);
+               pr_debug("%s: External IRQ%i virq=%x, hw=%x. type=%x\n",
+                        __func__, l2irq, virq, (int)irq, type);
+               return 0;
+       }
 
+       /* It is an internal SOC irq.  Choose the correct irq_chip */
        switch (l1irq) {
-       case MPC52xx_IRQ_L1_CRIT:
-               pr_debug("%s: Critical. l2=%x\n", __func__, l2irq);
-
-               BUG_ON(l2irq != 0);
-
-               type = mpc52xx_irqx_gettype(l2irq);
-               good_irqchip = &mpc52xx_extirq_irqchip;
-               break;
-
-       case MPC52xx_IRQ_L1_MAIN:
-               pr_debug("%s: Main IRQ[1-3] l2=%x\n", __func__, l2irq);
-
-               if ((l2irq >= 1) && (l2irq <= 3)) {
-                       type = mpc52xx_irqx_gettype(l2irq);
-                       good_irqchip = &mpc52xx_extirq_irqchip;
-               } else {
-                       good_irqchip = &mpc52xx_main_irqchip;
-               }
-               break;
-
-       case MPC52xx_IRQ_L1_PERP:
-               pr_debug("%s: Peripherals. l2=%x\n", __func__, l2irq);
-               good_irqchip = &mpc52xx_periph_irqchip;
-               break;
-
-       case MPC52xx_IRQ_L1_SDMA:
-               pr_debug("%s: SDMA. l2=%x\n", __func__, l2irq);
-               good_irqchip = &mpc52xx_sdma_irqchip;
-               break;
-
+       case MPC52xx_IRQ_L1_MAIN: irqchip = &mpc52xx_main_irqchip; break;
+       case MPC52xx_IRQ_L1_PERP: irqchip = &mpc52xx_periph_irqchip; break;
+       case MPC52xx_IRQ_L1_SDMA: irqchip = &mpc52xx_sdma_irqchip; break;
        default:
-               pr_err("%s: invalid virq requested (0x%x)\n", __func__, virq);
+               pr_err("%s: invalid irq: virq=%i, l1=%i, l2=%i\n",
+                      __func__, virq, l1irq, l2irq);
                return -EINVAL;
        }
 
-       switch (type) {
-       case IRQ_TYPE_EDGE_FALLING:
-       case IRQ_TYPE_EDGE_RISING:
-               good_handle = handle_edge_irq;
-               break;
-       default:
-               good_handle = handle_level_irq;
-       }
-
-       set_irq_chip_and_handler(virq, good_irqchip, good_handle);
-
-       pr_debug("%s: virq=%x, hw=%x. type=%x\n", __func__, virq,
-                (int)irq, type);
+       set_irq_chip_and_handler(virq, irqchip, handle_level_irq);
+       pr_debug("%s: virq=%x, l1=%i, l2=%i\n", __func__, virq, l1irq, l2irq);
 
        return 0;
 }
@@ -502,6 +471,8 @@ void __init mpc52xx_init_irq(void)
                panic(__FILE__  ": find_and_map failed on 'mpc5200-bestcomm'. "
                                "Check node !");
 
+       pr_debug("MPC5200 IRQ controller mapped to 0x%p\n", intr);
+
        /* Disable all interrupt sources. */
        out_be32(&sdma->IntPend, 0xffffffff);   /* 1 means clear pending */
        out_be32(&sdma->IntMask, 0xffffffff);   /* 1 means disabled */