[PATCH v2 4/9] ram: k3-ddrss: Add support for a partial inline ECC region

[Neha Malcom Francis]

Instead of defaulting to choosing the entire DDR region when enabling
inline ECC, allow picking of a range within the DDR space using DT to
enable.

It expects such a node within the memory node, in the absence of which
we resort to enabling inline ECC for the entire DDR region:

inline_ecc: protected@9e780000 {
        device_type = "ecc";
        reg = <0x9e780000 0x0080000>;
        bootph-all;
};

Signed-off-by: Neha Malcom Francis <n-fran...@ti.com>
---
 drivers/ram/k3-ddrss/k3-ddrss.c | 55 +++++++++++++++++++++++++++++++--
 1 file changed, 52 insertions(+), 3 deletions(-)

diff --git a/drivers/ram/k3-ddrss/k3-ddrss.c b/drivers/ram/k3-ddrss/k3-ddrss.c
index a94755c3542..cd117d7eba7 100644
--- a/drivers/ram/k3-ddrss/k3-ddrss.c
+++ b/drivers/ram/k3-ddrss/k3-ddrss.c
@@ -155,6 +155,7 @@ struct k3_ddrss_desc {
        lpddr4_obj *driverdt;
        lpddr4_config config;
        lpddr4_privatedata pd;
+       struct k3_ddrss_ecc_region ecc_range;
        struct k3_ddrss_ecc_region ecc_regions[K3_DDRSS_MAX_ECC_REG];
        u64 ecc_reserved_space;
        u64 ddr_bank_base[CONFIG_NR_DRAM_BANKS];
@@ -733,6 +734,30 @@ static void k3_ddrss_ddr_reg_init(struct k3_ddrss_desc 
*ddrss)
        writel(DDRSS_ECC_CTRL_REG_DEFAULT, ddrss->ddrss_ss_cfg + 
DDRSS_ECC_CTRL_REG);
 }
 
+static void k3_ddrss_ddr_inline_ecc_base_size_calc(struct k3_ddrss_ecc_region 
*range)
+{
+       fdt_addr_t base;
+       fdt_size_t size;
+       ofnode node1;
+
+       node1 = ofnode_null();
+
+       do {
+               node1 = ofnode_by_prop_value(node1, "device_type", "ecc", 4);
+       } while (!ofnode_is_enabled(node1));
+
+       base = ofnode_get_addr_size(node1, "reg", &size);
+
+       if (base == FDT_ADDR_T_NONE) {
+               debug("%s: Failed to get ECC node reg and size\n", __func__);
+               range->start = 0;
+               range->range = 0;
+       } else {
+               range->start = base;
+               range->range = size;
+       }
+}
+
 static void k3_ddrss_lpddr4_ecc_calc_reserved_mem(struct k3_ddrss_desc *ddrss)
 {
        fdtdec_setup_mem_size_base_lowest();
@@ -782,8 +807,11 @@ static void k3_ddrss_lpddr4_ecc_init(struct k3_ddrss_desc 
*ddrss)
 
 static int k3_ddrss_probe(struct udevice *dev)
 {
+       u64 end;
        int ret;
        struct k3_ddrss_desc *ddrss = dev_get_priv(dev);
+       __maybe_unused u32 ddr_ram_size, ecc_res;
+       __maybe_unused struct k3_ddrss_ecc_region *range = &ddrss->ecc_range;
 
        debug("%s(dev=%p)\n", __func__, dev);
 
@@ -821,9 +849,30 @@ static int k3_ddrss_probe(struct udevice *dev)
 
                k3_ddrss_lpddr4_ecc_calc_reserved_mem(ddrss);
 
-               /* Always configure one region that covers full DDR space */
-               ddrss->ecc_regions[0].start = 0;
-               ddrss->ecc_regions[0].range = ddrss->ddr_ram_size - 
ddrss->ecc_reserved_space;
+               k3_ddrss_ddr_inline_ecc_base_size_calc(range);
+
+               end = ddrss->ecc_range.start + ddrss->ecc_range.range;
+               ddr_ram_size = ddrss->ddr_ram_size;
+               ecc_res = ddrss->ecc_reserved_space;
+
+               if (!range->range) {
+                       /* Configure entire DDR space by default */
+                       debug("%s: Defaulting to protecting entire DDR space 
using inline ECC\n",
+                             __func__);
+                       ddrss->ecc_range.start = ddrss->ddr_bank_base[0];
+                       ddrss->ecc_range.range = ddr_ram_size - ecc_res;
+               } else {
+                       ddrss->ecc_range.start = range->start;
+                       ddrss->ecc_range.range = range->range;
+               }
+
+               if (end > (ddr_ram_size - ecc_res))
+                       ddrss->ecc_regions[0].range = ddr_ram_size - ecc_res;
+               else
+                       ddrss->ecc_regions[0].range = ddrss->ecc_range.range;
+
+               ddrss->ecc_regions[0].start = ddrss->ecc_range.start - 
ddrss->ddr_bank_base[0];
+
                k3_ddrss_lpddr4_ecc_init(ddrss);
        }
 
-- 
2.34.1