[PATCH 3/3] memory: brcmstb_memc: Add new DDR attributes

From: Florian Fainelli
Date: Fri Mar 24 2023 - 12:52:55 EST


Provide information about the DDR size, type, width, total width,
dual/single rank. This is useful for reporting purposes and inventory of
the system(s).

Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
---
drivers/memory/brcmstb_memc.c | 80 ++++++++++++++++++++++++++++++++++-
1 file changed, 79 insertions(+), 1 deletion(-)

diff --git a/drivers/memory/brcmstb_memc.c b/drivers/memory/brcmstb_memc.c
index 67c75e21c95e..032567dfd6e2 100644
--- a/drivers/memory/brcmstb_memc.c
+++ b/drivers/memory/brcmstb_memc.c
@@ -13,7 +13,14 @@

#define REG_MEMC_CNTRLR_CONFIG 0x00
#define CNTRLR_CONFIG_LPDDR4_SHIFT 5
-#define CNTRLR_CONFIG_MASK 0xf
+#define CNTRLR_CONFIG_MASK GENMASK(3, 0)
+#define CNTRLR_CONFIG_SIZE_SHIFT 4
+#define CNTRLR_CONFIG_SIZE_MASK GENMASK(7, 4)
+#define CNTRLR_CONFIG_WIDTH_SHIFT 8
+#define CNTRLR_CONFIG_WIDTH_MASK GENMASK(9, 8)
+#define CNTRLR_CONFIG_TOT_WIDTH_SHIFT 10
+#define CNTRLR_CONFIG_TOT_WIDTH_MASK GENMASK(11, 10)
+#define CNTRLR_CONFIG_RANK_SHIFT 16
#define REG_MEMC_SRPD_CFG_21 0x20
#define REG_MEMC_SRPD_CFG_20 0x34
#define REG_MEMC_SRPD_CFG_1x 0x3c
@@ -63,6 +70,67 @@ static int brcmstb_memc_srpd_config(struct brcmstb_memc *memc,
return 0;
}

+static ssize_t ddr_rank_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct brcmstb_memc *memc = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%s\n",
+ memc->config_reg & CNTRLR_CONFIG_RANK_SHIFT ?
+ "dual" : "single");
+}
+
+static ssize_t ddr_size_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct brcmstb_memc *memc = dev_get_drvdata(dev);
+ u32 val = (memc->config_reg & CNTRLR_CONFIG_SIZE_MASK) >>
+ CNTRLR_CONFIG_SIZE_SHIFT;
+
+ return sprintf(buf, "%dMb\n", 256 << val);
+}
+
+static ssize_t ddr_total_width_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct brcmstb_memc *memc = dev_get_drvdata(dev);
+ u32 val = (memc->config_reg & CNTRLR_CONFIG_TOT_WIDTH_MASK) >>
+ CNTRLR_CONFIG_TOT_WIDTH_SHIFT;
+
+ return sprintf(buf, "x%d\n", 8 << val);
+}
+
+static ssize_t ddr_type_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct brcmstb_memc *memc = dev_get_drvdata(dev);
+ const char *ddr_type_to_str[] = {
+ "DDR2",
+ "DDR3",
+ "DDR4",
+ "GDDR5M",
+ "GDDR5",
+ "LPDDR4",
+ };
+ u32 val = memc->config_reg & CNTRLR_CONFIG_MASK;
+ const char *type = "unknown";
+
+ if (val < ARRAY_SIZE(ddr_type_to_str))
+ type = ddr_type_to_str[val];
+
+ return sprintf(buf, "%s\n", type);
+}
+
+static ssize_t ddr_width_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct brcmstb_memc *memc = dev_get_drvdata(dev);
+ u32 val = (memc->config_reg & CNTRLR_CONFIG_WIDTH_MASK) >>
+ CNTRLR_CONFIG_WIDTH_SHIFT;
+
+ return sprintf(buf, "x%d\n", 8 << val);
+}
+
static ssize_t frequency_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
@@ -105,10 +173,20 @@ static ssize_t srpd_store(struct device *dev, struct device_attribute *attr,
return count;
}

+static DEVICE_ATTR_RO(ddr_rank);
+static DEVICE_ATTR_RO(ddr_size);
+static DEVICE_ATTR_RO(ddr_total_width);
+static DEVICE_ATTR_RO(ddr_type);
+static DEVICE_ATTR_RO(ddr_width);
static DEVICE_ATTR_RO(frequency);
static DEVICE_ATTR_RW(srpd);

static struct attribute *dev_attrs[] = {
+ &dev_attr_ddr_rank.attr,
+ &dev_attr_ddr_size.attr,
+ &dev_attr_ddr_total_width.attr,
+ &dev_attr_ddr_type.attr,
+ &dev_attr_ddr_width.attr,
&dev_attr_frequency.attr,
&dev_attr_srpd.attr,
NULL,
--
2.34.1