[PATCH v2 4/5] soc: qcom: Add LLCC support for multi channel DDR

[Komal Bajaj]

Add LLCC support for multi channel DDR configurations
based off of a feature register.

Signed-off-by: Komal Bajaj <quic_kbajaj@xxxxxxxxxxx>
---
 drivers/soc/qcom/llcc-qcom.c       | 56 ++++++++++++++++++++++++++++--
 include/linux/soc/qcom/llcc-qcom.h |  2 ++
 2 files changed, 55 insertions(+), 3 deletions(-)

diff --git a/drivers/soc/qcom/llcc-qcom.c b/drivers/soc/qcom/llcc-qcom.c
index 00699a0c047e..f4d3e266c629 100644
--- a/drivers/soc/qcom/llcc-qcom.c
+++ b/drivers/soc/qcom/llcc-qcom.c
@@ -17,6 +17,7 @@
 #include <linux/regmap.h>
 #include <linux/sizes.h>
 #include <linux/slab.h>
+#include <linux/firmware/qcom/qcom_scm.h>
 #include <linux/soc/qcom/llcc-qcom.h>
 
 #define ACTIVATE                      BIT(0)
@@ -924,6 +925,40 @@ static int qcom_llcc_cfg_program(struct platform_device *pdev,
 	return ret;
 }
 
+static int qcom_llcc_get_cfg_index(struct platform_device *pdev, u32 *cfg_index)
+{
+	struct device *dev = &pdev->dev;
+	struct resource *ch_res = NULL;
+
+	u32 ch_reg_sz;
+	u32 ch_reg_off;
+	u32 val;
+	int ret = 0;
+
+	ch_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "multi_channel_register");
+	if (ch_res) {
+		if (of_property_read_u32(dev->of_node, "multi-ch-bit-off", &ch_reg_off)) {
+			dev_err(&pdev->dev,
+				"Couldn't get offset for multi channel feature register\n");
+			return -ENODEV;
+		}
+		if (of_property_read_u32_index(dev->of_node, "multi-ch-bit-off", 1, &ch_reg_sz)) {
+			dev_err(&pdev->dev,
+				"Couldn't get size of multi channel feature register\n");
+			return -ENODEV;
+		}
+
+		if (qcom_scm_io_readl(ch_res->start, &val)) {
+			dev_err(&pdev->dev, "Couldn't access multi channel feature register\n");
+			ret = -EINVAL;
+		}
+		*cfg_index = (val >> ch_reg_off) & ((1 << ch_reg_sz) - 1);
+	} else
+		*cfg_index = 0;
+
+	return ret;
+}
+
 static int qcom_llcc_remove(struct platform_device *pdev)
 {
 	/* Set the global pointer to a error code to avoid referencing it */
@@ -956,10 +991,13 @@ static int qcom_llcc_probe(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	int ret, i;
 	struct platform_device *llcc_edac;
-	const struct qcom_llcc_config *cfg;
+	const struct qcom_llcc_config *cfg, *entry;
 	const struct llcc_slice_config *llcc_cfg;
+
 	u32 sz;
+	u32 cfg_index;
 	u32 version;
+	u32 no_of_entries = 0;
 
 	drv_data = devm_kzalloc(dev, sizeof(*drv_data), GFP_KERNEL);
 	if (!drv_data) {
@@ -999,8 +1037,20 @@ static int qcom_llcc_probe(struct platform_device *pdev)
 	num_banks >>= LLCC_LB_CNT_SHIFT;
 	drv_data->num_banks = num_banks;
 
-	llcc_cfg = cfg[0].sct_data;
-	sz = cfg[0].size;
+	ret = qcom_llcc_get_cfg_index(pdev, &cfg_index);
+	if (ret)
+		goto err;
+
+	for (entry = cfg; entry->sct_data; entry++, no_of_entries++)
+		;
+	if (cfg_index >= no_of_entries) {
+		ret = -EINVAL;
+		goto err;
+	}
+
+	drv_data->cfg_index = cfg_index;
+	llcc_cfg = cfg[cfg_index].sct_data;
+	sz = cfg[cfg_index].size;
 
 	for (i = 0; i < sz; i++)
 		if (llcc_cfg[i].slice_id > drv_data->max_slices)
diff --git a/include/linux/soc/qcom/llcc-qcom.h b/include/linux/soc/qcom/llcc-qcom.h
index ad1fd718169d..225891a02f5d 100644
--- a/include/linux/soc/qcom/llcc-qcom.h
+++ b/include/linux/soc/qcom/llcc-qcom.h
@@ -125,6 +125,7 @@ struct llcc_edac_reg_offset {
  * @cfg: pointer to the data structure for slice configuration
  * @edac_reg_offset: Offset of the LLCC EDAC registers
  * @lock: mutex associated with each slice
+ * @cfg_index: index of config table if multiple configs present for a target
  * @cfg_size: size of the config data table
  * @max_slices: max slices as read from device tree
  * @num_banks: Number of llcc banks
@@ -139,6 +140,7 @@ struct llcc_drv_data {
 	const struct llcc_slice_config *cfg;
 	const struct llcc_edac_reg_offset *edac_reg_offset;
 	struct mutex lock;
+	u32 cfg_index;
 	u32 cfg_size;
 	u32 max_slices;
 	u32 num_banks;
-- 
2.39.1