cpufreq: qcom-nvmem: add support for IPQ6018

IPQ6018 SoC series comes in multiple SKU-s, and not all of them support
high frequency OPP points.

SoC itself does however have a single bit in QFPROM to indicate the CPU
speed-bin.
That bit is used to indicate frequency limit of 1.5GHz, but that alone is
not enough as IPQ6000 only goes up to 1.2GHz, but SMEM ID can be used to
limit it further.

IPQ6018 compatible is blacklisted from DT platdev as the cpufreq device
will get created by NVMEM CPUFreq driver.
Signed-off-by: Robert Marko <robimarko@gmail.com>
[ Viresh: Fixed rebase conflict. ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

drivers/cpufreq/cpufreq-dt-platdev.c

@@ -180,6 +180,7 @@ static const struct of_device_id blocklist[] __initconst = {
 	{ .compatible = "ti,am62a7", },
 	{ .compatible = "ti,am62p5", },
 
+	{ .compatible = "qcom,ipq6018", },
 	{ .compatible = "qcom,ipq8064", },
 	{ .compatible = "qcom,apq8064", },
 	{ .compatible = "qcom,msm8974", },

drivers/cpufreq/qcom-cpufreq-nvmem.c

@@ -30,6 +30,8 @@
 
 #include <dt-bindings/arm/qcom,ids.h>
 
+#define IPQ6000_VERSION	BIT(2)
+
 struct qcom_cpufreq_drv;
 
 struct qcom_cpufreq_match_data {
@@ -225,6 +227,57 @@ static int qcom_cpufreq_krait_name_version(struct device *cpu_dev,
 	return ret;
 }
 
+static int qcom_cpufreq_ipq6018_name_version(struct device *cpu_dev,
+					     struct nvmem_cell *speedbin_nvmem,
+					     char **pvs_name,
+					     struct qcom_cpufreq_drv *drv)
+{
+	u32 msm_id;
+	int ret;
+	u8 *speedbin;
+	*pvs_name = NULL;
+
+	ret = qcom_smem_get_soc_id(&msm_id);
+	if (ret)
+		return ret;
+
+	speedbin = nvmem_cell_read(speedbin_nvmem, NULL);
+	if (IS_ERR(speedbin))
+		return PTR_ERR(speedbin);
+
+	switch (msm_id) {
+	case QCOM_ID_IPQ6005:
+	case QCOM_ID_IPQ6010:
+	case QCOM_ID_IPQ6018:
+	case QCOM_ID_IPQ6028:
+		/* Fuse Value    Freq    BIT to set
+		 * ---------------------------------
+		 *   2’b0     No Limit     BIT(0)
+		 *   2’b1     1.5 GHz      BIT(1)
+		 */
+		drv->versions = 1 << (unsigned int)(*speedbin);
+		break;
+	case QCOM_ID_IPQ6000:
+		/*
+		 * IPQ6018 family only has one bit to advertise the CPU
+		 * speed-bin, but that is not enough for IPQ6000 which
+		 * is only rated up to 1.2GHz.
+		 * So for IPQ6000 manually set BIT(2) based on SMEM ID.
+		 */
+		drv->versions = IPQ6000_VERSION;
+		break;
+	default:
+		dev_err(cpu_dev,
+			"SoC ID %u is not part of IPQ6018 family, limiting to 1.2GHz!\n",
+			msm_id);
+		drv->versions = IPQ6000_VERSION;
+		break;
+	}
+
+	kfree(speedbin);
+	return 0;
+}
+
 static const char *generic_genpd_names[] = { "perf", NULL };
 
 static const struct qcom_cpufreq_match_data match_data_kryo = {
@@ -246,6 +299,10 @@ static const struct qcom_cpufreq_match_data match_data_qcs404 = {
 	.genpd_names = qcs404_genpd_names,
 };
 
+static const struct qcom_cpufreq_match_data match_data_ipq6018 = {
+	.get_version = qcom_cpufreq_ipq6018_name_version,
+};
+
 static int qcom_cpufreq_probe(struct platform_device *pdev)
 {
 	struct qcom_cpufreq_drv *drv;
@@ -372,6 +429,7 @@ static const struct of_device_id qcom_cpufreq_match_list[] __initconst = {
 	{ .compatible = "qcom,msm8909", .data = &match_data_msm8909 },
 	{ .compatible = "qcom,msm8996", .data = &match_data_kryo },
 	{ .compatible = "qcom,qcs404", .data = &match_data_qcs404 },
+	{ .compatible = "qcom,ipq6018", .data = &match_data_ipq6018 },
 	{ .compatible = "qcom,ipq8064", .data = &match_data_krait },
 	{ .compatible = "qcom,apq8064", .data = &match_data_krait },
 	{ .compatible = "qcom,msm8974", .data = &match_data_krait },