qpnp-smb2: introduce workaround bit mask

Add a bit mask to enable workarounds only if they are needed for a
particular hardware revision.

Change-Id: Ibd9a896ff6746a48ddab249d7c8ab762ed3c2fbe
Signed-off-by: Harry Yang <harryy@codeaurora.org>
Signed-off-by: Nicholas Troast <ntroast@codeaurora.org>
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>

Documentation/devicetree/bindings/power/qcom-charger/qpnp-smb2.txt

@@ -21,6 +21,12 @@ Charger specific properties:
   Value type: <string>
   Definition: "qcom,qpnp-smb2".
 
+- qcom,pmic-revid
+  Usage:      required
+  Value type: phandle
+  Definition: Should specify the phandle of PMI's revid module. This is used to
+		identify the PMI subtype.
+
 - qcom,batteryless-platform
   Usage:      optional
   Value type: <empty>

drivers/power/qcom-charger/qpnp-smb2.c

@@ -18,6 +18,7 @@
 #include <linux/interrupt.h>
 #include <linux/of.h>
 #include <linux/of_irq.h>
+#include <linux/qpnp/qpnp-revid.h>
 #include <linux/regulator/driver.h>
 #include <linux/regulator/of_regulator.h>
 #include <linux/regulator/machine.h>
@@ -205,6 +206,7 @@ struct smb_dt_props {
 	int	wipower_max_uw;
 	u32	step_soc_threshold[STEP_CHARGING_MAX_STEPS - 1];
 	s32	step_cc_delta[STEP_CHARGING_MAX_STEPS];
+	struct	device_node *revid_dev_node;
 };
 
 struct smb2 {
@@ -1085,6 +1087,40 @@ static int smb2_init_hw(struct smb2 *chip)
 	return rc;
 }
 
+static int smb2_setup_wa_flags(struct smb2 *chip)
+{
+	struct pmic_revid_data *pmic_rev_id;
+	struct device_node *revid_dev_node;
+
+	revid_dev_node = of_parse_phandle(chip->chg.dev->of_node,
+					  "qcom,pmic-revid", 0);
+	if (!revid_dev_node) {
+		pr_err("Missing qcom,pmic-revid property\n");
+		return -EINVAL;
+	}
+
+	pmic_rev_id = get_revid_data(revid_dev_node);
+	if (IS_ERR_OR_NULL(pmic_rev_id)) {
+		/*
+		 * the revid peripheral must be registered, any failure
+		 * here only indicates that the rev-id module has not
+		 * probed yet.
+		 */
+		return -EPROBE_DEFER;
+	}
+
+	switch (pmic_rev_id->pmic_subtype) {
+	case PMICOBALT_SUBTYPE:
+		break;
+	default:
+		pr_err("PMIC subtype %d not supported\n",
+				pmic_rev_id->pmic_subtype);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 /****************************
  * DETERMINE INITIAL STATUS *
  ****************************/
@@ -1270,6 +1306,13 @@ static int smb2_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
+	rc = smb2_setup_wa_flags(chip);
+	if (rc < 0) {
+		if (rc != -EPROBE_DEFER)
+			pr_err("Couldn't setup wa flags rc=%d\n", rc);
+		return rc;
+	}
+
 	rc = smblib_init(chg);
 	if (rc < 0) {
 		pr_err("Smblib_init failed rc=%d\n", rc);

drivers/power/qcom-charger/smb-lib.h

@@ -161,6 +161,9 @@ struct smb_charger {
 
 	bool			step_chg_enabled;
 	bool			is_hdc;
+
+	/* workaround flag */
+	u32			wa_flags;
 };
 
 int smblib_read(struct smb_charger *chg, u16 addr, u8 *val);