From mboxrd@z Thu Jan  1 00:00:00 1970
From: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Date: Mon, 07 Jun 2010 15:06:32 +0000
Subject: Re: [PATCH 1/4] Add the directory mach-sh2007 for SH-2007 board support
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To: linux-sh@vger.kernel.org

On 06/07/10 12:02, Paul Mundt wrote:
 > On Sat, Jun 05, 2010 at 10:32:19PM +0900, Hitoshi Mitake wrote:
 >> On 06/02/10 15:32, Paul Mundt wrote:
 >>>> +/* Support for external interrupt pins in IRQ mode */
 >>>> +enum {IRQ0 = 1, IRQ1, IRQ2, IRQ3, IRQ4, IRQ5, IRQ6, IRQ7};
 >>>> +static struct intc_vect irq_vectors[] __initdata = {
 >>>> +	INTC_IRQ(IRQ0, IRQ_SMC0),
 >>>> +	INTC_IRQ(IRQ1, IRQ_SMC1),
 >>>> +	INTC_IRQ(IRQ2, IRQ_CFCARD),
 >>>> +	INTC_IRQ(IRQ3, IRQ_IDE),
 >>>> +	INTC_IRQ(IRQ4, 3),
 >>>> +	INTC_IRQ(IRQ5, 4),
 >>>> +	INTC_IRQ(IRQ6, 5),
 >>>> +	INTC_IRQ(IRQ7, 7),
 >>>> +};
 >>>> +
 >>>> +static struct intc_mask_reg irq_mask_registers[] __initdata = {
 >>>> +	{ INTC_INTMSK0, INTC_INTMSKCLR0, 32,
 >>>> +	  { IRQ0, IRQ1, IRQ2, IRQ3, IRQ4, IRQ5, IRQ6, IRQ7 } },
 >>>> +};
 >>>> +
 >>>> +static struct intc_prio_reg irq_prio_registers[] __initdata = {
 >>>> +	{ INTC_INTPRI, 0, 32, 4,
 >>>> +	  { IRQ0, IRQ1, IRQ2, IRQ3, IRQ4, IRQ5, IRQ6, IRQ7 } },
 >>>> +};
 >>>> +
 >>>> +static struct intc_sense_reg irq_sense_registers[] __initdata = {
 >>>> +	{ INTC_ICR1, 32, 2,
 >>>> +	  { IRQ0, IRQ1, IRQ2, IRQ3, IRQ4, IRQ5, IRQ6, IRQ7 } },
 >>>> +};
 >>>> +
 >>>> +static struct intc_mask_reg irq_ack_registers[] __initdata = {
 >>>> +	{ INTC_INTREQ, 0, 32,
 >>>> +	  { IRQ0, IRQ1, IRQ2, IRQ3, IRQ4, IRQ5, IRQ6, IRQ7 } },
 >>>> +};
 >>>> +
 >>>> +static DECLARE_INTC_DESC_ACK(intc_irq_desc, "sh7780-irq", 
irq_vectors,
 >>>> +			NULL, irq_mask_registers, irq_prio_registers,
 >>>> +			irq_sense_registers, irq_ack_registers);
 >>>> +
 >>> None of this is needed, it's all taken care of by the SH7780 CPU code
 >>> already.
 >>
 >> These IRQs are things for devicde specific,
 >> I think this is required for board support.
 >> # I'm an only newbie, if I make some mistakes,
 >> # please point out :)
 >
 > I suspect this just stems from a misunderstanding of how to interact with
 > the IRQ code. All of these registers are part of the SH7780 CPU IRQ
 > controllers, and have nothing to do with the device. The only thing that
 > is device specific is how these IRQs are used, and we already expose full
 > control for that to the boards.
 >
 > If you read through arch/sh/kernel/cpu/sh4a/setup-sh7780.c you can see
 > that everything is already centrally managed by the CPU, so the only
 > thing you need to take care of is the IRQ mapping and IRQ mode pins
 > setting.
 >
 > If your board has an FPGA that's chained off of the IRLs then you can set
 > the controller in to IRL mode, or if you're simply using them as IRQ0-7
 > directly and letting the CPU controller take care of the masking, then
 > you can simply throw the controller in to IRQ mode.
 >
 > Simply grep for plat_irq_setup_pins() to see how the CPU/board
 > interaction works for this, you'll likely want IRQ_MODE_IRQ for this
 > case.
 >

Ah, I noticed my misunderstanding.
  plat_irq_setup_pins(IRQ_MODE_IRQ);
is enough for me to init ICR.
Thanks for your correcting!

And I have a question,
Can I set evt2irq(INTEVT) to struct resource.start directly?
# INTEVT is the value like 0x220
If I do so, mv_irq_demux can be NULL because
evt2irq(INTEVT) is equal to the first argument of do_IRQ().

I don't know the traditional way of SH board support,
and it seems that there is no board takes the way I described above.
So I cannot judge this way is correct or not...