[MIPS] IRQ cleanups

This is a big irq cleanup patch.

* Use set_irq_chip() to register irq_chip.
* Initialize .mask, .unmask, .mask_ack field.  Functions for these
  method are already exist in most case.
* Do not initialize .startup, .shutdown, .enable, .disable fields if
  default routines provided by irq_chip_set_defaults() were suitable.
* Remove redundant irq_desc initializations.
* Remove unnecessary local_irq_save/local_irq_restore, spin_lock.

With this cleanup, it would be easy to switch to slightly lightwait
irq flow handlers (handle_level_irq(), etc.) instead of __do_IRQ().

Though whole this patch is quite large, changes in each irq_chip are
not quite simple.  Please review and test on your platform.  Thanks.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 6 insertions, 50 deletions

diff --git a/arch/mips/momentum/ocelot_c/uart-irq.c b/arch/mips/momentum/ocelot_c/uart-irq.c
index 510257dc205a..72faf81b36cc 100644
--- a/arch/mips/momentum/ocelot_c/uart-irq.c
+++ b/arch/mips/momentum/ocelot_c/uart-irq.c
@@ -60,39 +60,6 @@ static inline void unmask_uart_irq(unsigned int irq)
 }
 
 /*
- * Enables the IRQ in the FPGA
- */
-static void enable_uart_irq(unsigned int irq)
-{
-	unmask_uart_irq(irq);
-}
-
-/*
- * Initialize the IRQ in the FPGA
- */
-static unsigned int startup_uart_irq(unsigned int irq)
-{
-	unmask_uart_irq(irq);
-	return 0;
-}
-
-/*
- * Disables the IRQ in the FPGA
- */
-static void disable_uart_irq(unsigned int irq)
-{
-	mask_uart_irq(irq);
-}
-
-/*
- * Masks and ACKs an IRQ
- */
-static void mask_and_ack_uart_irq(unsigned int irq)
-{
-	mask_uart_irq(irq);
-}
-
-/*
  * End IRQ processing
  */
 static void end_uart_irq(unsigned int irq)
@@ -118,28 +85,17 @@ void ll_uart_irq(void)
 	do_IRQ(ls1bit8(irq_src) + 74);
 }
 
-#define shutdown_uart_irq	disable_uart_irq
-
 struct irq_chip uart_irq_type = {
 	.typename = "UART/FPGA",
-	.startup = startup_uart_irq,
-	.shutdown = shutdown_uart_irq,
-	.enable = enable_uart_irq,
-	.disable = disable_uart_irq,
-	.ack = mask_and_ack_uart_irq,
+	.ack = mask_uart_irq,
+	.mask = mask_uart_irq,
+	.mask_ack = mask_uart_irq,
+	.unmask = unmask_uart_irq,
 	.end = end_uart_irq,
 };
 
 void uart_irq_init(void)
 {
-	/* Reset irq handlers pointers to NULL */
-	irq_desc[80].status = IRQ_DISABLED;
-	irq_desc[80].action = 0;
-	irq_desc[80].depth = 2;
-	irq_desc[80].chip = &uart_irq_type;
-
-	irq_desc[81].status = IRQ_DISABLED;
-	irq_desc[81].action = 0;
-	irq_desc[81].depth = 2;
-	irq_desc[81].chip = &uart_irq_type;
+	set_irq_chip(80, &uart_irq_type);
+	set_irq_chip(81, &uart_irq_type);
 }