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From:   Komal Bajaj <quic_kbajaj@quicinc.com>
To:     <agross@kernel.org>, <andersson@kernel.org>,
        <konrad.dybcio@linaro.org>, <robh+dt@kernel.org>,
        <krzysztof.kozlowski+dt@linaro.org>, <conor+dt@kernel.org>,
        <srinivas.kandagatla@linaro.org>
CC:     <linux-arm-msm@vger.kernel.org>, <devicetree@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>,
        Komal Bajaj <quic_kbajaj@quicinc.com>
Subject: [PATCH v6 4/6] soc: qcom: Add LLCC support for multi channel DDR
Date:   Wed, 2 Aug 2023 14:44:26 +0530
Message-ID: <20230802091429.20892-5-quic_kbajaj@quicinc.com>
In-Reply-To: <20230802091429.20892-1-quic_kbajaj@quicinc.com>
References: <20230802091429.20892-1-quic_kbajaj@quicinc.com>
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Add LLCC support for multi channel DDR configuration
based on a feature register.

Signed-off-by: Komal Bajaj <quic_kbajaj@quicinc.com>
---
 drivers/soc/qcom/llcc-qcom.c | 30 ++++++++++++++++++++++++++----
 1 file changed, 26 insertions(+), 4 deletions(-)

diff --git a/drivers/soc/qcom/llcc-qcom.c b/drivers/soc/qcom/llcc-qcom.c
index 808c5aaa7407..f6ed4e4aaf3b 100644
--- a/drivers/soc/qcom/llcc-qcom.c
+++ b/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/of_device.h>
 #include <linux/regmap.h>
@@ -999,6 +1000,26 @@ 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 != DEFAULT_CONFIG) {
+			ret = -EINVAL;
+			return ret;
+		}
+		*cfg_index = DEFAULT_CONFIG - 1;
+		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 */
@@ -1035,6 +1056,7 @@ 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;

@@ -1052,11 +1074,11 @@ static int qcom_llcc_probe(struct platform_device *pdev)
 	}

 	cfgs = of_device_get_match_data(&pdev->dev);
-	if (cfgs->num_config != DEFAULT_CONFIG) {
-		ret = -EINVAL;
+	ret = qcom_llcc_get_cfg_index(pdev, &cfg_index, cfgs->num_config);
+	if (ret)
 		goto err;
-	}
-	cfg = &cfgs->llcc_config[DEFAULT_CONFIG - 1];
+
+	cfg = &cfgs->llcc_config[cfg_index];

 	ret = regmap_read(regmap, cfg->reg_offset[LLCC_COMMON_STATUS0], &num_banks);
 	if (ret)
--
2.41.0