soc: qcom: Add LLCC support for multi channel DDR

Add LLCC support for multi channel DDR configuration
based on a feature register.

Signed-off-by: Komal Bajaj <quic_kbajaj@quicinc.com>
Acked-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20230830105654.28057-5-quic_kbajaj@quicinc.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

drivers/soc/qcom/llcc-qcom.c

@@ -12,6 +12,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
+#include <linux/nvmem-consumer.h>
 #include <linux/of.h>
 #include <linux/regmap.h>
 #include <linux/sizes.h>
@@ -995,6 +996,24 @@ static int qcom_llcc_cfg_program(struct platform_device *pdev,
 	return ret;
 }
 
+static int qcom_llcc_get_cfg_index(struct platform_device *pdev, u8 *cfg_index, int num_config)
+{
+	int ret;
+
+	ret = nvmem_cell_read_u8(&pdev->dev, "multi-chan-ddr", cfg_index);
+	if (ret == -ENOENT || ret == -EOPNOTSUPP) {
+		if (num_config > 1)
+			return -EINVAL;
+		*cfg_index = 0;
+		return 0;
+	}
+
+	if (!ret && *cfg_index >= num_config)
+		ret = -EINVAL;
+
+	return ret;
+}
+
 static int qcom_llcc_remove(struct platform_device *pdev)
 {
 	/* Set the global pointer to a error code to avoid referencing it */
@@ -1031,6 +1050,7 @@ static int qcom_llcc_probe(struct platform_device *pdev)
 	const struct qcom_llcc_config *cfg;
 	const struct llcc_slice_config *llcc_cfg;
 	u32 sz;
+	u8 cfg_index;
 	u32 version;
 	struct regmap *regmap;
 
@@ -1052,7 +1072,10 @@ static int qcom_llcc_probe(struct platform_device *pdev)
 		ret = -EINVAL;
 		goto err;
 	}
-	cfg = &cfgs->llcc_config[0];
+	ret = qcom_llcc_get_cfg_index(pdev, &cfg_index, cfgs->num_config);
+	if (ret)
+		goto err;
+	cfg = &cfgs->llcc_config[cfg_index];
 
 	ret = regmap_read(regmap, cfg->reg_offset[LLCC_COMMON_STATUS0], &num_banks);
 	if (ret)