thermal/drivers/k3_j72xx_bandgap: Map fuse_base only for erratum workaround

Some of TI's J721E SoCs require a software trimming procedure for the
temperature monitors to function properly. To determine if a particular
J721E is not affected by this erratum, both bits in the WKUP_SPARE_FUSE0
region must be set. Other SoCs, not affected by this erratum, will not
need this region.

Map the 'fuse_base' region only when the erratum fix is needed.

Signed-off-by: Bryan Brattlof <bb@ti.com>
Link: https://lore.kernel.org/r/20221031232702.10339-5-bb@ti.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@kernel.org>

diff --git a/drivers/thermal/k3_j72xx_bandgap.c b/drivers/thermal/k3_j72xx_bandgap.c
index 395a73c..031ea10 100644 (file)
--- a/drivers/thermal/k3_j72xx_bandgap.c
+++ b/drivers/thermal/k3_j72xx_bandgap.c
@@ -386,15 +386,32 @@ static int k3_j72xx_bandgap_probe(struct platform_device *pdev)
        if (IS_ERR(bgp->cfg2_base))
                return PTR_ERR(bgp->cfg2_base);
 
-       res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
-       fuse_base = devm_ioremap_resource(dev, res);
-       if (IS_ERR(fuse_base))
-               return PTR_ERR(fuse_base);
-
        driver_data = of_device_get_match_data(dev);
        if (driver_data)
                workaround_needed = driver_data->has_errata_i2128;
 
+       /*
+        * Some of TI's J721E SoCs require a software trimming procedure
+        * for the temperature monitors to function properly. To determine
+        * if this particular SoC is NOT affected, both bits in the
+        * WKUP_SPARE_FUSE0[31:30] will be set (0xC0000000) indicating
+        * when software trimming should NOT be applied.
+        *
+        * https://www.ti.com/lit/er/sprz455c/sprz455c.pdf
+        */
+       if (workaround_needed) {
+               res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
+               fuse_base = devm_ioremap_resource(dev, res);
+               if (IS_ERR(fuse_base))
+                       return PTR_ERR(fuse_base);
+
+               if ((readl(fuse_base) & 0xc0000000) == 0xc0000000)
+                       workaround_needed = false;
+       }
+
+       dev_dbg(bgp->dev, "Work around %sneeded\n",
+               workaround_needed ? "" : "not ");
+
        pm_runtime_enable(dev);
        ret = pm_runtime_get_sync(dev);
        if (ret < 0) {
@@ -427,13 +444,6 @@ static int k3_j72xx_bandgap_probe(struct platform_device *pdev)
                goto err_free_ref_table;
        }
 
-       /* Workaround not needed if bit30/bit31 is set even for J721e */
-       if (workaround_needed && (readl(fuse_base + 0x0) & 0xc0000000) == 0xc0000000)
-               workaround_needed = false;
-
-       dev_dbg(bgp->dev, "Work around %sneeded\n",
-               workaround_needed ? "" : "not ");
-
        if (!workaround_needed)
                init_table(5, ref_table, golden_factors);
        else