brcmfmac: access PMU registers using standalone PMU core if available

On recent Broadcom chipsets PMU is present as separated core and it
can't be accessed using ChipCommon anymore as it fails with e.g.:
[   18.198412] Unhandled fault: imprecise external abort (0x1406) at 0xb6da200f

Add a new helper function that will return a proper core that should be
used for accessing PMU registers.
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/broadcom/brcm80211/brcmfmac/chip.c

@@ -1014,6 +1014,7 @@ static int brcmf_chip_setup(struct brcmf_chip_priv *chip)
 {
 	struct brcmf_chip *pub;
 	struct brcmf_core_priv *cc;
+	struct brcmf_core *pmu;
 	u32 base;
 	u32 val;
 	int ret = 0;
@@ -1030,9 +1031,10 @@ static int brcmf_chip_setup(struct brcmf_chip_priv *chip)
 							 capabilities_ext));
 
 	/* get pmu caps & rev */
+	pmu = brcmf_chip_get_pmu(pub); /* after reading cc_caps_ext */
 	if (pub->cc_caps & CC_CAP_PMU) {
 		val = chip->ops->read32(chip->ctx,
-					CORE_CC_REG(base, pmucapabilities));
+					CORE_CC_REG(pmu->base, pmucapabilities));
 		pub->pmurev = val & PCAP_REV_MASK;
 		pub->pmucaps = val;
 	}
@@ -1131,6 +1133,23 @@ struct brcmf_core *brcmf_chip_get_chipcommon(struct brcmf_chip *pub)
 	return &cc->pub;
 }
 
+struct brcmf_core *brcmf_chip_get_pmu(struct brcmf_chip *pub)
+{
+	struct brcmf_core *cc = brcmf_chip_get_chipcommon(pub);
+	struct brcmf_core *pmu;
+
+	/* See if there is separated PMU core available */
+	if (cc->rev >= 35 &&
+	    pub->cc_caps_ext & BCMA_CC_CAP_EXT_AOB_PRESENT) {
+		pmu = brcmf_chip_get_core(pub, BCMA_CORE_PMU);
+		if (pmu)
+			return pmu;
+	}
+
+	/* Fallback to ChipCommon core for older hardware */
+	return cc;
+}
+
 bool brcmf_chip_iscoreup(struct brcmf_core *pub)
 {
 	struct brcmf_core_priv *core;
@@ -1301,6 +1320,7 @@ bool brcmf_chip_sr_capable(struct brcmf_chip *pub)
 {
 	u32 base, addr, reg, pmu_cc3_mask = ~0;
 	struct brcmf_chip_priv *chip;
+	struct brcmf_core *pmu = brcmf_chip_get_pmu(pub);
 
 	brcmf_dbg(TRACE, "Enter\n");
 
@@ -1320,9 +1340,9 @@ bool brcmf_chip_sr_capable(struct brcmf_chip *pub)
 	case BRCM_CC_4335_CHIP_ID:
 	case BRCM_CC_4339_CHIP_ID:
 		/* read PMU chipcontrol register 3 */
-		addr = CORE_CC_REG(base, chipcontrol_addr);
+		addr = CORE_CC_REG(pmu->base, chipcontrol_addr);
 		chip->ops->write32(chip->ctx, addr, 3);
-		addr = CORE_CC_REG(base, chipcontrol_data);
+		addr = CORE_CC_REG(pmu->base, chipcontrol_data);
 		reg = chip->ops->read32(chip->ctx, addr);
 		return (reg & pmu_cc3_mask) != 0;
 	case BRCM_CC_43430_CHIP_ID:
@@ -1330,12 +1350,12 @@ bool brcmf_chip_sr_capable(struct brcmf_chip *pub)
 		reg = chip->ops->read32(chip->ctx, addr);
 		return reg != 0;
 	default:
-		addr = CORE_CC_REG(base, pmucapabilities_ext);
+		addr = CORE_CC_REG(pmu->base, pmucapabilities_ext);
 		reg = chip->ops->read32(chip->ctx, addr);
 		if ((reg & PCAPEXT_SR_SUPPORTED_MASK) == 0)
 			return false;
 
-		addr = CORE_CC_REG(base, retention_ctl);
+		addr = CORE_CC_REG(pmu->base, retention_ctl);
 		reg = chip->ops->read32(chip->ctx, addr);
 		return (reg & (PMU_RCTL_MACPHY_DISABLE_MASK |
 			       PMU_RCTL_LOGIC_DISABLE_MASK)) == 0;

drivers/net/wireless/broadcom/brcm80211/brcmfmac/chip.h

@@ -85,6 +85,7 @@ struct brcmf_chip *brcmf_chip_attach(void *ctx,
 void brcmf_chip_detach(struct brcmf_chip *chip);
 struct brcmf_core *brcmf_chip_get_core(struct brcmf_chip *chip, u16 coreid);
 struct brcmf_core *brcmf_chip_get_chipcommon(struct brcmf_chip *chip);
+struct brcmf_core *brcmf_chip_get_pmu(struct brcmf_chip *pub);
 bool brcmf_chip_iscoreup(struct brcmf_core *core);
 void brcmf_chip_coredisable(struct brcmf_core *core, u32 prereset, u32 reset);
 void brcmf_chip_resetcore(struct brcmf_core *core, u32 prereset, u32 reset,

drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c

@@ -3615,7 +3615,6 @@ brcmf_sdio_drivestrengthinit(struct brcmf_sdio_dev *sdiodev,
 	const struct sdiod_drive_str *str_tab = NULL;
 	u32 str_mask;
 	u32 str_shift;
-	u32 base;
 	u32 i;
 	u32 drivestrength_sel = 0;
 	u32 cc_data_temp;
@@ -3658,14 +3657,15 @@ brcmf_sdio_drivestrengthinit(struct brcmf_sdio_dev *sdiodev,
 	}
 
 	if (str_tab != NULL) {
+		struct brcmf_core *pmu = brcmf_chip_get_pmu(ci);
+
 		for (i = 0; str_tab[i].strength != 0; i++) {
 			if (drivestrength >= str_tab[i].strength) {
 				drivestrength_sel = str_tab[i].sel;
 				break;
 			}
 		}
-		base = brcmf_chip_get_chipcommon(ci)->base;
-		addr = CORE_CC_REG(base, chipcontrol_addr);
+		addr = CORE_CC_REG(pmu->base, chipcontrol_addr);
 		brcmf_sdiod_regwl(sdiodev, addr, 1, NULL);
 		cc_data_temp = brcmf_sdiod_regrl(sdiodev, addr, NULL);
 		cc_data_temp &= ~str_mask;
@@ -3835,8 +3835,7 @@ brcmf_sdio_probe_attach(struct brcmf_sdio *bus)
 		goto fail;
 
 	/* set PMUControl so a backplane reset does PMU state reload */
-	reg_addr = CORE_CC_REG(brcmf_chip_get_chipcommon(bus->ci)->base,
-			       pmucontrol);
+	reg_addr = CORE_CC_REG(brcmf_chip_get_pmu(bus->ci)->base, pmucontrol);
 	reg_val = brcmf_sdiod_regrl(bus->sdiodev, reg_addr, &err);
 	if (err)
 		goto fail;