spmi: pmic-arb: do not ack and clear peripheral interrupts in cleanup_irq

Currently, cleanup_irq() is invoked when a peripheral's interrupt
fires and there is no mapping present in the interrupt domain of
spmi interrupt controller.

The cleanup_irq clears the arbiter bit, clears the pmic interrupt
and disables it at the pmic in that order. The last disable in
cleanup_irq races with request_irq() in that it stomps over the
enable issued by request_irq. Fix this by not writing to the pmic
in cleanup_irq. The latched bit will be left set in the pmic,
which will not send us more interrupts even if the enable bit
stays enabled.

When a client wants to request an interrupt, use the activate
callback on the irq_domain to clear latched bit. This ensures
that the latched, if set due to the above changes in cleanup_irq
or when the bootloader leaves it set, gets cleaned up, paving way
for upcoming interrupts to trigger.

With this, there is a possibility of unwanted triggering of
interrupt right after the latched bit is cleared - the interrupt
may be left enabled too. To avoid that, clear the enable first
followed by clearing the latched bit in the activate callback.

Change-Id: If126d6f6cdf6c944ca513c53a71a91e225ee63e2
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>
diff --git a/drivers/spmi/spmi-pmic-arb.c b/drivers/spmi/spmi-pmic-arb.c
index 6c8154d..a5bfeab 100644
--- a/drivers/spmi/spmi-pmic-arb.c
+++ b/drivers/spmi/spmi-pmic-arb.c
@@ -533,18 +533,6 @@
 		"cleanup_irq apid=%d sid=0x%x per=0x%x irq=%d\n",
 		apid, sid, per, id);
 	writel_relaxed(irq_mask, pa->intr + pa->ver_ops->irq_clear(apid));
-
-	if (pmic_arb_write_cmd(pa->spmic, SPMI_CMD_EXT_WRITEL, sid,
-		       (per << 8) + QPNPINT_REG_LATCHED_CLR, &irq_mask, 1))
-		dev_err_ratelimited(&pa->spmic->dev,
-				"failed to ack irq_mask = 0x%x for ppid = %x\n",
-				irq_mask, ppid);
-
-	if (pmic_arb_write_cmd(pa->spmic, SPMI_CMD_EXT_WRITEL, sid,
-			       (per << 8) + QPNPINT_REG_EN_CLR, &irq_mask, 1))
-		dev_err_ratelimited(&pa->spmic->dev,
-				"failed to ack irq_mask = 0x%x for ppid = %x\n",
-				irq_mask, ppid);
 }
 
 static void periph_interrupt(struct spmi_pmic_arb *pa, u16 apid, bool show)
@@ -721,6 +709,17 @@
 			| IRQCHIP_SKIP_SET_WAKE,
 };
 
+static void qpnpint_irq_domain_activate(struct irq_domain *domain,
+					struct irq_data *d)
+{
+	u8 irq = HWIRQ_IRQ(d->hwirq);
+	u8 buf;
+
+	buf = BIT(irq);
+	qpnpint_spmi_write(d, QPNPINT_REG_EN_CLR, &buf, 1);
+	qpnpint_spmi_write(d, QPNPINT_REG_LATCHED_CLR, &buf, 1);
+}
+
 static int qpnpint_irq_domain_dt_translate(struct irq_domain *d,
 					   struct device_node *controller,
 					   const u32 *intspec,
@@ -1186,6 +1185,7 @@
 static const struct irq_domain_ops pmic_arb_irq_domain_ops = {
 	.map	= qpnpint_irq_domain_map,
 	.xlate	= qpnpint_irq_domain_dt_translate,
+	.activate	= qpnpint_irq_domain_activate,
 };
 
 static void spmi_pmic_arb_resume(void)