sh: extend INTC with force_enable

Extend the shared INTC code with force_enable support to
allow keeping mask bits statically enabled. Needed by
upcoming INTC SDHI patches that mux together a bunch of
vectors to a single linux interrupt which is masked by
a priority register, but needs individual mask bits
constantly enabled.

Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

2 files changed, 133 insertions, 19 deletions

diff --git a/drivers/sh/intc.c b/drivers/sh/intc.c
index 5ec0fffa7db4..ccee18945d91 100644
--- a/drivers/sh/intc.c
+++ b/drivers/sh/intc.c
@@ -259,6 +259,43 @@ static void intc_disable(unsigned int irq)
         }
 }
 
+static void (*intc_enable_noprio_fns[])(unsigned long addr,
+                                        unsigned long handle,
+                                        void (*fn)(unsigned long,
+                                                   unsigned long,
+                                                   unsigned long),
+                                        unsigned int irq) = {
+        [MODE_ENABLE_REG] = intc_mode_field,
+        [MODE_MASK_REG] = intc_mode_zero,
+        [MODE_DUAL_REG] = intc_mode_field,
+        [MODE_PRIO_REG] = intc_mode_field,
+        [MODE_PCLR_REG] = intc_mode_field,
+};
+
+static void intc_enable_disable(struct intc_desc_int *d,
+                                unsigned long handle, int do_enable)
+{
+        unsigned long addr;
+        unsigned int cpu;
+        void (*fn)(unsigned long, unsigned long,
+                   void (*)(unsigned long, unsigned long, unsigned long),
+                   unsigned int);
+
+        if (do_enable) {
+                for (cpu = 0; cpu < SMP_NR(d, _INTC_ADDR_E(handle)); cpu++) {
+                        addr = INTC_REG(d, _INTC_ADDR_E(handle), cpu);
+                        fn = intc_enable_noprio_fns[_INTC_MODE(handle)];
+                        fn(addr, handle, intc_reg_fns[_INTC_FN(handle)], 0);
+                }
+        } else {
+                for (cpu = 0; cpu < SMP_NR(d, _INTC_ADDR_D(handle)); cpu++) {
+                        addr = INTC_REG(d, _INTC_ADDR_D(handle), cpu);
+                        fn = intc_disable_fns[_INTC_MODE(handle)];
+                        fn(addr, handle, intc_reg_fns[_INTC_FN(handle)], 0);
+                }
+        }
+}
+
 static int intc_set_wake(unsigned int irq, unsigned int on)
 {
         return 0; /* allow wakeup, but setup hardware in intc_suspend() */
@@ -417,19 +454,21 @@ static intc_enum __init intc_grp_id(struct intc_desc *desc,
         return 0;
 }
 
-static unsigned int __init intc_mask_data(struct intc_desc *desc,
-                                          struct intc_desc_int *d,
-                                          intc_enum enum_id, int do_grps)
+static unsigned int __init _intc_mask_data(struct intc_desc *desc,
+                                           struct intc_desc_int *d,
+                                           intc_enum enum_id,
+                                           unsigned int *reg_idx,
+                                           unsigned int *fld_idx)
 {
         struct intc_mask_reg *mr = desc->hw.mask_regs;
-        unsigned int i, j, fn, mode;
+        unsigned int fn, mode;
         unsigned long reg_e, reg_d;
 
-        for (i = 0; mr && enum_id && i < desc->hw.nr_mask_regs; i++) {
-                mr = desc->hw.mask_regs + i;
+        while (mr && enum_id && *reg_idx < desc->hw.nr_mask_regs) {
+                mr = desc->hw.mask_regs + *reg_idx;
 
-                for (j = 0; j < ARRAY_SIZE(mr->enum_ids); j++) {
-                        if (mr->enum_ids[j] != enum_id)
+                for (; *fld_idx < ARRAY_SIZE(mr->enum_ids); (*fld_idx)++) {
+                        if (mr->enum_ids[*fld_idx] != enum_id)
                                 continue;
 
                         if (mr->set_reg && mr->clr_reg) {
@@ -455,29 +494,49 @@ static unsigned int __init intc_mask_data(struct intc_desc *desc,
                                         intc_get_reg(d, reg_e),
                                         intc_get_reg(d, reg_d),
                                         1,
-                                        (mr->reg_width - 1) - j);
+                                        (mr->reg_width - 1) - *fld_idx);
                 }
+
+                *fld_idx = 0;
+                (*reg_idx)++;
         }
 
+        return 0;
+}
+
+static unsigned int __init intc_mask_data(struct intc_desc *desc,
+                                          struct intc_desc_int *d,
+                                          intc_enum enum_id, int do_grps)
+{
+        unsigned int i = 0;
+        unsigned int j = 0;
+        unsigned int ret;
+
+        ret = _intc_mask_data(desc, d, enum_id, &i, &j);
+        if (ret)
+                return ret;
+
         if (do_grps)
                 return intc_mask_data(desc, d, intc_grp_id(desc, enum_id), 0);
 
         return 0;
 }
 
-static unsigned int __init intc_prio_data(struct intc_desc *desc,
-                                          struct intc_desc_int *d,
-                                          intc_enum enum_id, int do_grps)
+static unsigned int __init _intc_prio_data(struct intc_desc *desc,
+                                           struct intc_desc_int *d,
+                                           intc_enum enum_id,
+                                           unsigned int *reg_idx,
+                                           unsigned int *fld_idx)
 {
         struct intc_prio_reg *pr = desc->hw.prio_regs;
-        unsigned int i, j, fn, mode, bit;
+        unsigned int fn, n, mode, bit;
         unsigned long reg_e, reg_d;
 
-        for (i = 0; pr && enum_id && i < desc->hw.nr_prio_regs; i++) {
-                pr = desc->hw.prio_regs + i;
+        while (pr && enum_id && *reg_idx < desc->hw.nr_prio_regs) {
+                pr = desc->hw.prio_regs + *reg_idx;
 
-                for (j = 0; j < ARRAY_SIZE(pr->enum_ids); j++) {
-                        if (pr->enum_ids[j] != enum_id)
+                for (; *fld_idx < ARRAY_SIZE(pr->enum_ids); (*fld_idx)++) {
+                        if (pr->enum_ids[*fld_idx] != enum_id)
                                 continue;
 
                         if (pr->set_reg && pr->clr_reg) {
@@ -495,24 +554,69 @@ static unsigned int __init intc_prio_data(struct intc_desc *desc,
                         }
 
                         fn += (pr->reg_width >> 3) - 1;
+                        n = *fld_idx + 1;
 
-                        BUG_ON((j + 1) * pr->field_width > pr->reg_width);
+                        BUG_ON(n * pr->field_width > pr->reg_width);
 
-                        bit = pr->reg_width - ((j + 1) * pr->field_width);
+                        bit = pr->reg_width - (n * pr->field_width);
 
                         return _INTC_MK(fn, mode,
                                         intc_get_reg(d, reg_e),
                                         intc_get_reg(d, reg_d),
                                         pr->field_width, bit);
                 }
+
+                *fld_idx = 0;
+                (*reg_idx)++;
         }
 
+        return 0;
+}
+
+static unsigned int __init intc_prio_data(struct intc_desc *desc,
+                                          struct intc_desc_int *d,
+                                          intc_enum enum_id, int do_grps)
+{
+        unsigned int i = 0;
+        unsigned int j = 0;
+        unsigned int ret;
+
+        ret = _intc_prio_data(desc, d, enum_id, &i, &j);
+        if (ret)
+                return ret;
+
         if (do_grps)
                 return intc_prio_data(desc, d, intc_grp_id(desc, enum_id), 0);
 
         return 0;
 }
 
+static void __init intc_enable_disable_enum(struct intc_desc *desc,
+                                            struct intc_desc_int *d,
+                                            intc_enum enum_id, int enable)
+{
+        unsigned int i, j, data;
+
+        /* go through and enable/disable all mask bits */
+        i = j = 0;
+        do {
+                data = _intc_mask_data(desc, d, enum_id, &i, &j);
+                if (data)
+                        intc_enable_disable(d, data, enable);
+                j++;
+        } while (data);
+
+        /* go through and enable/disable all priority fields */
+        i = j = 0;
+        do {
+                data = _intc_prio_data(desc, d, enum_id, &i, &j);
+                if (data)
+                        intc_enable_disable(d, data, enable);
+
+                j++;
+        } while (data);
+}
+
 static unsigned int __init intc_ack_data(struct intc_desc *desc,
                                           struct intc_desc_int *d,
                                           intc_enum enum_id)
@@ -747,6 +851,11 @@ void __init register_intc_controller(struct intc_desc *desc)
                 d->chip.mask_ack = intc_mask_ack;
         }
 
+
+        /* disable bits matching force_enable before registering irqs */
+        if (desc->force_enable)
+                intc_enable_disable_enum(desc, d, desc->force_enable, 0);
+
         BUG_ON(k > 256); /* _INTC_ADDR_E() and _INTC_ADDR_D() are 8 bits */
 
         /* register the vectors one by one */
@@ -792,6 +901,10 @@ void __init register_intc_controller(struct intc_desc *desc)
                         set_irq_data(irq2, (void *)irq);
                 }
         }
+
+        /* enable bits matching force_enable after registering irqs */
+        if (desc->force_enable)
+                intc_enable_disable_enum(desc, d, desc->force_enable, 1);
 }
 
 static int intc_suspend(struct sys_device *dev, pm_message_t state)
diff --git a/include/linux/sh_intc.h b/include/linux/sh_intc.h
index 7b37526bb73f..66b4b0c45e71 100644
--- a/include/linux/sh_intc.h
+++ b/include/linux/sh_intc.h
@@ -71,6 +71,7 @@ struct intc_hw_desc {
 
 struct intc_desc {
         char *name;
+        intc_enum force_enable;
         struct intc_hw_desc hw;
 };