Re: [PATCH V1 03/15] spmi: pmic-arb: fix inconsistent use of apid and chan

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 2017-05-31 07:01, Stephen Boyd wrote:
On 05/30, Kiran Gunda wrote:
From: Abhijeet Dharmapurikar <adharmap@xxxxxxxxxxxxxx>

The driver currently uses "apid" and "chan" to mean apid. Remove
the use of chan and use only apid.

I'm not so sure. It currently uses "chan" to mean the offset to
add to the "PMIC Arbiter channel registers" so that we can access
the appropriate peripheral via the arbiter registers. I actually
can't remember what APID or PPID stand for, so perhaps describing
that as well would be helpful so we can navigate this acronym
soup.

Yes. You are correct.
Will describe the "apid" and "ppid" in the next version patch.

On a SPMI bus there is allocation to manage up to 4K peripherals.
However, in practice only few peripherals are instantiated
and only few among the instantiated ones actually interrupt.

APID is CPU's way of keeping track of peripherals that could interrupt.
There is a table that maps the 256 interrupting peripherals to
a number between 0 and 255. This number is called APID. Information about
that interrupting peripheral is stored in registers offset by its
corresponding apid.

That's all fine, but perhaps we shouldn't worry about "apid"
being attached to interrupts? I mean, I can imagine some
peripheral that doesn't interrupt, but we want to read/write it
and that must be done with the "channel" or "apid" or really the
"magic offset from the base of the channel registers" to do so.
Probably APID is fine, as long as APID means "application
processor peripheral id" or something along those lines.

Yes. you are right. APID means "Application peripheral id".

Signed-off-by: Abhijeet Dharmapurikar <adharmap@xxxxxxxxxxxxxx>
Signed-off-by: Kiran Gunda <kgunda@xxxxxxxxxxxxxx>
---
drivers/spmi/spmi-pmic-arb.c | 68 ++++++++++++++++++++++----------------------
 1 file changed, 34 insertions(+), 34 deletions(-)

diff --git a/drivers/spmi/spmi-pmic-arb.c b/drivers/spmi/spmi-pmic-arb.c
index 7f918ea..7201611 100644
--- a/drivers/spmi/spmi-pmic-arb.c
+++ b/drivers/spmi/spmi-pmic-arb.c
@@ -117,7 +117,7 @@ enum pmic_arb_cmd_op_code {
  * @spmic:		SPMI controller object
  * @apid_to_ppid:	in-memory copy of APID -> PPID mapping table.
  * @ver_ops:		version dependent operations.
- * @ppid_to_chan in-memory copy of PPID -> channel (APID) mapping table. + * @ppid_to_apid in-memory copy of PPID -> channel (APID) mapping table.

PPID->APID? No channel?
Sure. Will change it the next patch.

  *			v2 only.
  */
 struct spmi_pmic_arb {
@@ -140,9 +140,9 @@ struct spmi_pmic_arb {
 	struct spmi_controller	*spmic;
 	u16			*apid_to_ppid;
 	const struct pmic_arb_ver_ops *ver_ops;
-	u16			*ppid_to_chan;
-	u16			last_channel;
-	u8			*chan_to_owner;
+	u16			*ppid_to_apid;
+	u16			last_apid;
+	u8			*apid_to_owner;
 };

 /**
@@ -772,22 +772,22 @@ static int qpnpint_irq_domain_map(struct irq_domain *d,
 	return 0;
 }

-static u16 pmic_arb_find_chan(struct spmi_pmic_arb *pa, u16 ppid)
+static u16 pmic_arb_find_apid(struct spmi_pmic_arb *pa, u16 ppid)
 {
 	u32 regval, offset;
-	u16 chan;
+	u16 apid;
 	u16 id;

 	/*
 	 * PMIC_ARB_REG_CHNL is a table in HW mapping channel to ppid.

Is this comment still relevant?
We will change channel to apid in the next patch.

-	 * ppid_to_chan is an in-memory invert of that table.
+	 * ppid_to_apid is an in-memory invert of that table.
 	 */
-	for (chan = pa->last_channel; chan < pa->max_periph; chan++) {
+	for (apid = pa->last_apid; apid < pa->max_periph; apid++) {
 		regval = readl_relaxed(pa->cnfg +
-				      SPMI_OWNERSHIP_TABLE_REG(chan));
-		pa->chan_to_owner[chan] = SPMI_OWNERSHIP_PERIPH2OWNER(regval);
+				      SPMI_OWNERSHIP_TABLE_REG(apid));
+		pa->apid_to_owner[apid] = SPMI_OWNERSHIP_PERIPH2OWNER(regval);

-		offset = PMIC_ARB_REG_CHNL(chan);
+		offset = PMIC_ARB_REG_CHNL(apid);
 		if (offset >= pa->core_size)
 			break;

@@ -796,15 +796,15 @@ static u16 pmic_arb_find_chan(struct spmi_pmic_arb *pa, u16 ppid)
 			continue;

 		id = (regval >> 8) & PMIC_ARB_PPID_MASK;
-		pa->ppid_to_chan[id] = chan | PMIC_ARB_CHAN_VALID;
+		pa->ppid_to_apid[id] = apid | PMIC_ARB_CHAN_VALID;

Why do we still call the flag PMIC_ARB_CHAN_VALID then? Shouldn't
it be PMIC_ARB_APID_VALID?

Yes. Agree. Will change it to PMIC_ARB_APID_VALID in the next patch.
 		if (id == ppid) {
-			chan |= PMIC_ARB_CHAN_VALID;
+			apid |= PMIC_ARB_CHAN_VALID;
 			break;
 		}
 	}
-	pa->last_channel = chan & ~PMIC_ARB_CHAN_VALID;
+	pa->last_apid = apid & ~PMIC_ARB_CHAN_VALID;

-	return chan;
+	return apid;
 }


--
To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [Linux for Sparc]     [IETF Annouce]     [Security]     [Bugtraq]     [Linux MIPS]     [ECOS]     [Asterisk Internet PBX]     [Linux API]

  Powered by Linux