[PATCH v4 3/5] misc: k3_avs: Check validity of efuse voltage data

[Aniket Limaye]

From: Reid Tonking <reidt at ti.com>

k3_avs driver checks opp_ids when probing and overwrites the voltage
values in vd_data for the respective board. The new k3_avs_check_opp()
can be called from board files to check the efuse data and returns 0 if
valid.

Also add the same check in k3_avs_program_voltage() to error out if
the efuse data was not valid.

Signed-off-by: Reid Tonking <reidt at ti.com>
Signed-off-by: Aniket Limaye <a-limaye at ti.com>
---

v4:
- Update function name to k3_avs_check_opp and update description
- Link to v3: https://lore.kernel.org/u-boot/20241116071615.839623-4-a-limaye@ti.com/

v3:
- Fix voltage spelling in k3_check_opp() function description. No
  functional change
- Link to v2: https://lore.kernel.org/u-boot/20241023130033.1826413-4-a-limaye@ti.com/

v2:
- Update to also handle invalid efuse voltage reading in
  k3_avs_program_voltage() and reflect the same change in commit msg.
- Link to v1: https://lore.kernel.org/u-boot/20241017062911.2241167-4-a-limaye@ti.com/
---
 drivers/misc/k3_avs.c | 32 ++++++++++++++++++++++++++++++++
 include/k3-avs.h      |  1 +
 2 files changed, 33 insertions(+)

diff --git a/drivers/misc/k3_avs.c b/drivers/misc/k3_avs.c
index 9d950d034a5..0774e0a4c9e 100644
--- a/drivers/misc/k3_avs.c
+++ b/drivers/misc/k3_avs.c
@@ -121,6 +121,11 @@ static int k3_avs_program_voltage(struct k3_avs_privdata *priv,
 	if (!vd->supply)
 		return -ENODEV;
 
+	if (!volt) {
+		dev_err(priv->dev, "No efuse found for opp_%d\n", opp_id);
+		return -EINVAL;
+	}
+
 	vd->opp = opp_id;
 	vd->flags |= VD_FLAG_INIT_DONE;
 
@@ -192,6 +197,33 @@ static int match_opp(struct vd_data *vd, u32 freq)
 	return -EINVAL;
 }
 
+/**
+ * k3_check_opp: Check for presence of opp efuse
+ * @dev: AVS device
+ * @vdd_id: voltage domain ID
+ * @opp_id: opp id to check if voltage is present
+ *
+ * Checks to see if an opp has voltage. k3_avs probe will populate
+ * voltage data if efuse is present. Returns 0 if data is valid.
+ */
+int k3_avs_check_opp(struct udevice *dev, int vdd_id, int opp_id)
+{
+	struct k3_avs_privdata *priv = dev_get_priv(dev);
+	struct vd_data *vd;
+	int volt;
+
+	vd = get_vd(priv, vdd_id);
+	if (!vd)
+		return -EINVAL;
+
+	volt = vd->opps[opp_id].volt;
+	if (volt)
+		return 0;
+
+	printf("No efuse found for opp_%d\n", opp_id);
+	return -EINVAL;
+}
+
 /**
  * k3_avs_notify_freq: Notify clock rate change towards AVS subsystem
  * @dev_id: Device ID for the clock to be changed
diff --git a/include/k3-avs.h b/include/k3-avs.h
index f6f1031c9cc..5a973e4ed45 100644
--- a/include/k3-avs.h
+++ b/include/k3-avs.h
@@ -27,5 +27,6 @@
 
 int k3_avs_set_opp(struct udevice *dev, int vdd_id, int opp_id);
 int k3_avs_notify_freq(int dev_id, int clk_id, u32 freq);
+int k3_avs_check_opp(struct udevice *dev, int vdd_id, int opp_id);
 
 #endif
-- 
2.47.0