[PATCH 3/3] cpufreq: qcom-nvmem: add compatible fallback for ipq806x for no SMEM

[Christian Marangi <ansuelsmth@gmail.com>]

On some IPQ806x SoC SMEM might be not initialized by SBL. This is the
case for some Google devices (the OnHub family) that can't make use of
SMEM to detect the SoC ID.

To handle these specific case, check if the SMEM is not initialized (by
checking if the qcom_smem_get_soc_id returns -ENODEV) and fallback to
OF machine compatible checking to identify the SoC variant.

Notice that the checking order is important as the machine compatible
are normally defined with the specific one following the generic SoC.
(for example compatible = "qcom,ipq8065", "qcom,ipq8064")

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
---
 drivers/cpufreq/qcom-cpufreq-nvmem.c | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/drivers/cpufreq/qcom-cpufreq-nvmem.c b/drivers/cpufreq/qcom-cpufreq-nvmem.c
index 3a8ed723a23e..c88a79a177b1 100644
--- a/drivers/cpufreq/qcom-cpufreq-nvmem.c
+++ b/drivers/cpufreq/qcom-cpufreq-nvmem.c
@@ -257,8 +257,8 @@ static int qcom_cpufreq_ipq8064_name_version(struct device *cpu_dev,
 					     char **pvs_name,
 					     struct qcom_cpufreq_drv *drv)
 {
+	int msm_id = -1, ret = 0;
 	int speed = 0, pvs = 0;
-	int msm_id, ret = 0;
 	u8 *speedbin;
 	size_t len;
 
@@ -275,8 +275,21 @@ static int qcom_cpufreq_ipq8064_name_version(struct device *cpu_dev,
 	get_krait_bin_format_a(cpu_dev, &speed, &pvs, speedbin);
 
 	ret = qcom_smem_get_soc_id(&msm_id);
-	if (ret)
-		goto exit;
+	if (ret) {
+		if (ret != -ENODEV)
+			goto exit;
+
+		/* Fallback to compatible match with no SMEM initialized */
+		if (of_machine_is_compatible("qcom,ipq8062"))
+			msm_id = QCOM_ID_IPQ8062;
+		else if (of_machine_is_compatible("qcom,ipq8065") ||
+			 of_machine_is_compatible("qcom,ipq8069"))
+			msm_id = QCOM_ID_IPQ8065;
+		else if (of_machine_is_compatible("qcom,ipq8064") ||
+			 of_machine_is_compatible("qcom,ipq8066") ||
+			 of_machine_is_compatible("qcom,ipq8068"))
+			msm_id = QCOM_ID_IPQ8064;
+	}
 
 	switch (msm_id) {
 	case QCOM_ID_IPQ8062:
-- 
2.51.0