[PATCH 4/4] soc: samsung: exynos-chipid: fix revision calculation for gs101

[Alexey Klimov]

The main revision for gs101 SoC is not reported in the CHIPID_REV
register. The gs101 Product ID and revisions registers have a behaviour
split between old Exynos SoCs and new SoCs. The sub-revision is
reported in CHIPID_REV register in [19:16] bits but main revision
is still present in Product ID [7:0].

To construct soc_info->revision correctly for gs101 the main_rev
should not be reset from a value read from CHIPID_REV.

Signed-off-by: Alexey Klimov <alexey.klimov@xxxxxxxxxx>
---
 drivers/soc/samsung/exynos-chipid.c       | 20 ++++++++++++++++----
 include/linux/soc/samsung/exynos-chipid.h |  1 +
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/drivers/soc/samsung/exynos-chipid.c b/drivers/soc/samsung/exynos-chipid.c
index 7fee6094db12..3b952ffd8cf7 100644
--- a/drivers/soc/samsung/exynos-chipid.c
+++ b/drivers/soc/samsung/exynos-chipid.c
@@ -87,14 +87,26 @@ static int exynos_chipid_get_chipid_info(struct regmap *regmap,
 	soc_info->product_id = val & EXYNOS_MASK;
 
 	if (data->rev_reg != EXYNOS_CHIPID_REG_PRO_ID) {
-		ret = regmap_read(regmap, data->rev_reg, &val);
+		unsigned int val2;
+
+		ret = regmap_read(regmap, data->rev_reg, &val2);
 		if (ret < 0)
 			return ret;
+
+		if (data->main_rev_shift == 0)
+			main_rev = (val >> data->main_rev_shift)
+				   & EXYNOS_REV_PART_MASK_GS101;
+		else
+			main_rev = (val2 >> data->main_rev_shift)
+				   & EXYNOS_REV_PART_MASK;
+
+		sub_rev = (val2 >> data->sub_rev_shift) & EXYNOS_REV_PART_MASK;
+	} else {
+		main_rev = (val >> data->main_rev_shift) & EXYNOS_REV_PART_MASK;
+		sub_rev = (val >> data->sub_rev_shift) & EXYNOS_REV_PART_MASK;
 	}
-	main_rev = (val >> data->main_rev_shift) & EXYNOS_REV_PART_MASK;
-	sub_rev = (val >> data->sub_rev_shift) & EXYNOS_REV_PART_MASK;
-	soc_info->revision = (main_rev << EXYNOS_REV_PART_SHIFT) | sub_rev;
 
+	soc_info->revision = (main_rev << EXYNOS_REV_PART_SHIFT) | sub_rev;
 	return 0;
 }
 
diff --git a/include/linux/soc/samsung/exynos-chipid.h b/include/linux/soc/samsung/exynos-chipid.h
index 62f0e2531068..1eb13068f513 100644
--- a/include/linux/soc/samsung/exynos-chipid.h
+++ b/include/linux/soc/samsung/exynos-chipid.h
@@ -10,6 +10,7 @@
 
 #define EXYNOS_CHIPID_REG_PRO_ID	0x00
 #define EXYNOS_REV_PART_MASK		0xf
+#define EXYNOS_REV_PART_MASK_GS101	0xff
 #define EXYNOS_REV_PART_SHIFT		4
 #define EXYNOS_MASK			0xfffff000
 
-- 
2.43.0