[PATCH v2 1/2] soc: qcom: pmic_glink: Add RTC client support

[Kamal Wadhwa]

On some Qualcomm targets like Hamoa and Glymur, PMIC RTC is only reachable over
the GLINK interface, so add a new RTC auxiliary device ("rtc-glink") to let the
new RTC glink driver bind against it, mirroring the existing
altmode/UCSI/power-supply clients.

Also add pmic_glink_client_unregister() so the RTC aux client can detach from the
clients list before unregistering the RTC in order to avoid use-after-free issue
in a scenario when an alarm IRQ is received during teardown.

Enable the RTC client on Glymur and Hamoa/X1E80100 variants, as only those
currently support this RTC client from the firmware side.

Assisted-by: Claude:claude-sonnet-5
Signed-off-by: Raj Aryan <raryan@xxxxxxxxxxxxxxxx>
Signed-off-by: Kamal Wadhwa <kamal.wadhwa@xxxxxxxxxxxxxxxx>
---
 drivers/soc/qcom/pmic_glink.c       | 43 ++++++++++++++++++++++++++++++++++++-
 include/linux/soc/qcom/pmic_glink.h |  1 +
 2 files changed, 43 insertions(+), 1 deletion(-)

diff --git a/drivers/soc/qcom/pmic_glink.c b/drivers/soc/qcom/pmic_glink.c
index 84fd0c82c0c4..8af6f4a65e61 100644
--- a/drivers/soc/qcom/pmic_glink.c
+++ b/drivers/soc/qcom/pmic_glink.c
@@ -21,6 +21,7 @@ enum {
 	PMIC_GLINK_CLIENT_BATT = 0,
 	PMIC_GLINK_CLIENT_ALTMODE,
 	PMIC_GLINK_CLIENT_UCSI,
+	PMIC_GLINK_CLIENT_RTC,
 };
 
 struct pmic_glink_data {
@@ -40,6 +41,7 @@ struct pmic_glink {
 	struct auxiliary_device altmode_aux;
 	struct auxiliary_device ps_aux;
 	struct auxiliary_device ucsi_aux;
+	struct auxiliary_device rtc_aux;
 
 	/* serializing client_state and pdr_state updates */
 	struct mutex state_lock;
@@ -118,6 +120,17 @@ void pmic_glink_client_register(struct pmic_glink_client *client)
 }
 EXPORT_SYMBOL_GPL(pmic_glink_client_register);
 
+void pmic_glink_client_unregister(struct pmic_glink_client *client)
+{
+	struct pmic_glink *pg = client->pg;
+	unsigned long flags;
+
+	spin_lock_irqsave(&pg->client_lock, flags);
+	list_del_init(&client->node);
+	spin_unlock_irqrestore(&pg->client_lock, flags);
+}
+EXPORT_SYMBOL_GPL(pmic_glink_client_unregister);
+
 int pmic_glink_send(struct pmic_glink_client *client, void *data, size_t len)
 {
 	struct pmic_glink *pg = client->pg;
@@ -342,6 +355,12 @@ static int pmic_glink_probe(struct platform_device *pdev)
 			goto out_release_altmode_aux;
 	}
 
+	if (pg->data->client_mask & BIT(PMIC_GLINK_CLIENT_RTC)) {
+		ret = pmic_glink_add_aux_device(pg, &pg->rtc_aux, "rtc-glink");
+		if (ret)
+			goto out_release_ps_aux;
+	}
+
 	if (pg->data->charger_pdr_service_name && pg->data->charger_pdr_service_path) {
 		service = pdr_add_lookup(pg->pdr, pg->data->charger_pdr_service_name,
 					 pg->data->charger_pdr_service_path);
@@ -359,6 +378,9 @@ static int pmic_glink_probe(struct platform_device *pdev)
 	return 0;
 
 out_release_aux_devices:
+	if (pg->data->client_mask & BIT(PMIC_GLINK_CLIENT_RTC))
+		pmic_glink_del_aux_device(pg, &pg->rtc_aux);
+out_release_ps_aux:
 	if (pg->data->client_mask & BIT(PMIC_GLINK_CLIENT_BATT))
 		pmic_glink_del_aux_device(pg, &pg->ps_aux);
 out_release_altmode_aux:
@@ -385,11 +407,20 @@ static void pmic_glink_remove(struct platform_device *pdev)
 		pmic_glink_del_aux_device(pg, &pg->altmode_aux);
 	if (pg->data->client_mask & BIT(PMIC_GLINK_CLIENT_UCSI))
 		pmic_glink_del_aux_device(pg, &pg->ucsi_aux);
+	if (pg->data->client_mask & BIT(PMIC_GLINK_CLIENT_RTC))
+		pmic_glink_del_aux_device(pg, &pg->rtc_aux);
 
 	guard(mutex)(&__pmic_glink_lock);
 	__pmic_glink = NULL;
 }
 
+static const struct pmic_glink_data pmic_glink_glymur_data = {
+	.client_mask = BIT(PMIC_GLINK_CLIENT_BATT) |
+		       BIT(PMIC_GLINK_CLIENT_ALTMODE) |
+		       BIT(PMIC_GLINK_CLIENT_UCSI) |
+		       BIT(PMIC_GLINK_CLIENT_RTC),
+};
+
 static const struct pmic_glink_data pmic_glink_adsp_data = {
 	.client_mask = BIT(PMIC_GLINK_CLIENT_BATT) |
 		       BIT(PMIC_GLINK_CLIENT_ALTMODE) |
@@ -404,10 +435,20 @@ static const struct pmic_glink_data pmic_glink_soccp_data = {
 		       BIT(PMIC_GLINK_CLIENT_UCSI),
 };
 
+static const struct pmic_glink_data pmic_glink_x1e80100_data = {
+	.client_mask = BIT(PMIC_GLINK_CLIENT_BATT) |
+		       BIT(PMIC_GLINK_CLIENT_ALTMODE) |
+		       BIT(PMIC_GLINK_CLIENT_UCSI) |
+		       BIT(PMIC_GLINK_CLIENT_RTC),
+	.charger_pdr_service_name = "tms/servreg",
+	.charger_pdr_service_path = "msm/adsp/charger_pd",
+};
+
 static const struct of_device_id pmic_glink_of_match[] = {
-	{ .compatible = "qcom,glymur-pmic-glink", .data = &pmic_glink_soccp_data },
+	{ .compatible = "qcom,glymur-pmic-glink", .data = &pmic_glink_glymur_data },
 	{ .compatible = "qcom,kaanapali-pmic-glink", .data = &pmic_glink_soccp_data },
 	{ .compatible = "qcom,pmic-glink", .data = &pmic_glink_adsp_data },
+	{ .compatible = "qcom,x1e80100-pmic-glink", .data = &pmic_glink_x1e80100_data },
 	{}
 };
 MODULE_DEVICE_TABLE(of, pmic_glink_of_match);
diff --git a/include/linux/soc/qcom/pmic_glink.h b/include/linux/soc/qcom/pmic_glink.h
index 7cddf1027752..c78dc7a8c99e 100644
--- a/include/linux/soc/qcom/pmic_glink.h
+++ b/include/linux/soc/qcom/pmic_glink.h
@@ -29,5 +29,6 @@ struct pmic_glink_client *devm_pmic_glink_client_alloc(struct device *dev,
 						       void (*pdr)(void *, int),
 						       void *priv);
 void pmic_glink_client_register(struct pmic_glink_client *client);
+void pmic_glink_client_unregister(struct pmic_glink_client *client);
 
 #endif

-- 
2.43.0