[PATCH v2 04/11] thermal: k3_j72xx_bandgap: map fuse_base only for erratum workaround

Bryan Brattlof
2022-10-25T19:15:47Z

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>
---
drivers/thermal/k3_j72xx_bandgap.c | 37 ++++++++++++++++++------------
1 file changed, 22 insertions(+), 15 deletions(-)

diff --git a/drivers/thermal/k3_j72xx_bandgap.c b/drivers/thermal/k3_j72xx_bandgap.c
index 71bf65e6afaed..031ea1091909a 100644
--- 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
@@ -501,9 +511,6 @@ static int k3_j72xx_bandgap_probe(struct platform_device *pdev)
*/
kfree(ref_table);

- if (workaround_needed)
- devm_iounmap(dev, fuse_base);
-
return 0;

err_free_ref_table:
--
2.38.1