[PATCH 06/14] m68k/atari: use dedicated irq_chip for timer D interrupts

Michael Schmitz
2013-03-25T01:16:57Z

The MFP timer D is used as a polling timer for EtherNEC and NetUSBee
on Atari. Set up a dedicated IRQ chip for timer D to simplify interrupt
sharing, and use the new 'polling' IRQ handler for its interrupts.

Signed-off-by: Michael Schmitz <schmitz@debian.org>
---
arch/m68k/atari/ataints.c | 70 +++++++++++++++++++++++++++++++++++++
arch/m68k/include/asm/atariints.h | 9 +++++
2 files changed, 79 insertions(+), 0 deletions(-)

diff --git a/arch/m68k/atari/ataints.c b/arch/m68k/atari/ataints.c
index 3f41092..2cf7349 100644
--- a/arch/m68k/atari/ataints.c
+++ b/arch/m68k/atari/ataints.c
@@ -122,6 +122,62 @@ static struct irq_chip atari_irq_chip = {
};

/*
+ * ST-MFP timer D chained interrupts - each driver gets its own timer
+ * interrupt instance.
+ */
+
+struct mfptimerbase {
+ volatile struct MFP *mfp;
+ unsigned char mfp_mask, mfp_data;
+ unsigned short int_mask;
+ int handler_irq, mfptimer_irq, server_irq;
+ char *name;
+} stmfp_base = {
+ .mfp = &st_mfp,
+ .int_mask = 0x0,
+ .handler_irq = IRQ_MFP_TIMD,
+ .mfptimer_irq = IRQ_MFP_TIMER1,
+ .name = "MFP Timer D"
+};
+
+static irqreturn_t mfptimer_handler(int irq, void *dev_id)
+{
+ struct mfptimerbase *base = dev_id;
+ int mach_irq;
+ unsigned char ints;
+
+ mach_irq = base->mfptimer_irq;
+ ints = base->int_mask;
+ for (; ints; mach_irq++, ints >>= 1) {
+ if (ints & 1)
+ generic_handle_irq(mach_irq);
+ }
+ return IRQ_HANDLED;
+}
+
+
+static void atari_mfptimer_enable(struct irq_data *data)
+{
+ int mfp_num = data->irq - IRQ_MFP_TIMER1;
+ stmfp_base.int_mask |= 1 << mfp_num;
+ atari_enable_irq(IRQ_MFP_TIMD);
+}
+
+static void atari_mfptimer_disable(struct irq_data *data)
+{
+ int mfp_num = data->irq - IRQ_MFP_TIMER1;
+ stmfp_base.int_mask &= ~(1 << mfp_num);
+ if (!stmfp_base.int_mask)
+ atari_disable_irq(IRQ_MFP_TIMD);
+}
+
+static struct irq_chip atari_mfptimer_chip = {
+ .name = "timer_d",
+ .irq_enable = atari_mfptimer_enable,
+ .irq_disable = atari_mfptimer_disable,
+};
+
+/*
* void atari_init_IRQ (void)
*
* Parameters: None
@@ -198,6 +254,20 @@ void __init atari_init_IRQ(void)
/* Initialize the PSG: all sounds off, both ports output */
sound_ym.rd_data_reg_sel = 7;
sound_ym.wd_data = 0xff;
+
+ m68k_setup_irq_controller(&atari_mfptimer_chip, handle_polled_irq,
+ IRQ_MFP_TIMER1, 8);
+
+ /* prepare timer D data for use as poll interrupt */
+ /* set Timer D data Register - needs to be > 0 */
+ st_mfp.tim_dt_d = 254; /* < 100 Hz */
+ /* start timer D, div = 1:100 */
+ st_mfp.tim_ct_cd = (st_mfp.tim_ct_cd & 0xf0) | 0x6;
+
+ /* request timer D dispatch handler */
+ if (request_irq(IRQ_MFP_TIMD, mfptimer_handler, IRQF_SHARED,
+ stmfp_base.name, &stmfp_base))
+ pr_err("Couldn't register %s interrupt\n", stmfp_base.name);
}

diff --git a/arch/m68k/include/asm/atariints.h b/arch/m68k/include/asm/atariints.h
index 12c759a..953e0ac 100644
--- a/arch/m68k/include/asm/atariints.h
+++ b/arch/m68k/include/asm/atariints.h
@@ -94,6 +94,15 @@
#define IRQ_SCCA_RX (52)
#define IRQ_SCCA_SPCOND (54)

+/* shared MFP timer D interrupts - hires timer for EtherNEC et al. */
+#define IRQ_MFP_TIMER1 (64)
+#define IRQ_MFP_TIMER2 (65)
+#define IRQ_MFP_TIMER3 (66)
+#define IRQ_MFP_TIMER4 (67)
+#define IRQ_MFP_TIMER5 (68)
+#define IRQ_MFP_TIMER6 (69)
+#define IRQ_MFP_TIMER7 (70)
+#define IRQ_MFP_TIMER8 (71)

#define INT_CLK 24576 /* CLK while int_clk =2.456MHz and divide = 100 */
#define INT_TICKS 246 /* to make sched_time = 99.902... HZ */
--
1.7.0.4