[PATCH 1/3] soc: samsung: exynos-chipid: Pass revision reg offsets

[Sam Protsenko]

Old Exynos SoCs have both Product ID and Revision ID in one single
register, while new SoCs tend to have two separate registers for those
IDs. Implement handling of both cases by passing Revision ID register
offsets in driver data.

Signed-off-by: Sam Protsenko <semen.protsenko at linaro.org>
---
 drivers/soc/samsung/exynos-chipid.c       | 67 +++++++++++++++++++----
 include/linux/soc/samsung/exynos-chipid.h |  6 +-
 2 files changed, 58 insertions(+), 15 deletions(-)

diff --git a/drivers/soc/samsung/exynos-chipid.c b/drivers/soc/samsung/exynos-chipid.c
index 5c1d0f97f766..1264a18aef97 100644
--- a/drivers/soc/samsung/exynos-chipid.c
+++ b/drivers/soc/samsung/exynos-chipid.c
@@ -16,6 +16,7 @@
 #include <linux/errno.h>
 #include <linux/mfd/syscon.h>
 #include <linux/of.h>
+#include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
 #include <linux/slab.h>
@@ -24,6 +25,17 @@
 
 #include "exynos-asv.h"
 
+struct exynos_chipid_variant {
+	unsigned int rev_reg;		/* revision register offset */
+	unsigned int main_rev_bit;	/* main revision offset */
+	unsigned int sub_rev_bit;	/* sub revision offset */
+};
+
+struct exynos_chipid_info {
+	u32 product_id;
+	u32 revision;
+};
+
 static const struct exynos_soc_id {
 	const char *name;
 	unsigned int id;
@@ -49,31 +61,55 @@ static const char *product_id_to_soc_id(unsigned int product_id)
 	int i;
 
 	for (i = 0; i < ARRAY_SIZE(soc_ids); i++)
-		if ((product_id & EXYNOS_MASK) == soc_ids[i].id)
+		if (product_id == soc_ids[i].id)
 			return soc_ids[i].name;
 	return NULL;
 }
 
+static int exynos_chipid_get_chipid_info(struct regmap *regmap,
+		const struct exynos_chipid_variant *data,
+		struct exynos_chipid_info *soc_info)
+{
+	int ret;
+	unsigned int val, main_rev, sub_rev;
+
+	ret = regmap_read(regmap, EXYNOS_CHIPID_REG_PRO_ID, &val);
+	if (ret < 0)
+		return ret;
+	soc_info->product_id = val & EXYNOS_MASK;
+
+	ret = regmap_read(regmap, data->rev_reg, &val);
+	if (ret < 0)
+		return ret;
+	main_rev = (val >> data->main_rev_bit) & EXYNOS_REV_PART_LEN;
+	sub_rev = (val >> data->sub_rev_bit) & EXYNOS_REV_PART_LEN;
+	soc_info->revision = (main_rev << EXYNOS_REV_PART_OFF) | sub_rev;
+
+	return 0;
+}
+
 static int exynos_chipid_probe(struct platform_device *pdev)
 {
+	const struct exynos_chipid_variant *drv_data;
+	struct exynos_chipid_info soc_info;
 	struct soc_device_attribute *soc_dev_attr;
 	struct soc_device *soc_dev;
 	struct device_node *root;
 	struct regmap *regmap;
-	u32 product_id;
-	u32 revision;
 	int ret;
 
+	drv_data = of_device_get_match_data(&pdev->dev);
+	if (!drv_data)
+		return -EINVAL;
+
 	regmap = device_node_to_regmap(pdev->dev.of_node);
 	if (IS_ERR(regmap))
 		return PTR_ERR(regmap);
 
-	ret = regmap_read(regmap, EXYNOS_CHIPID_REG_PRO_ID, &product_id);
+	ret = exynos_chipid_get_chipid_info(regmap, drv_data, &soc_info);
 	if (ret < 0)
 		return ret;
 
-	revision = product_id & EXYNOS_REV_MASK;
-
 	soc_dev_attr = devm_kzalloc(&pdev->dev, sizeof(*soc_dev_attr),
 				    GFP_KERNEL);
 	if (!soc_dev_attr)
@@ -86,8 +122,8 @@ static int exynos_chipid_probe(struct platform_device *pdev)
 	of_node_put(root);
 
 	soc_dev_attr->revision = devm_kasprintf(&pdev->dev, GFP_KERNEL,
-						"%x", revision);
-	soc_dev_attr->soc_id = product_id_to_soc_id(product_id);
+						"%x", soc_info.revision);
+	soc_dev_attr->soc_id = product_id_to_soc_id(soc_info.product_id);
 	if (!soc_dev_attr->soc_id) {
 		pr_err("Unknown SoC\n");
 		return -ENODEV;
@@ -106,7 +142,7 @@ static int exynos_chipid_probe(struct platform_device *pdev)
 
 	dev_info(soc_device_to_device(soc_dev),
 		 "Exynos: CPU[%s] PRO_ID[0x%x] REV[0x%x] Detected\n",
-		 soc_dev_attr->soc_id, product_id, revision);
+		 soc_dev_attr->soc_id, soc_info.product_id, soc_info.revision);
 
 	return 0;
 
@@ -125,9 +161,18 @@ static int exynos_chipid_remove(struct platform_device *pdev)
 	return 0;
 }
 
+static const struct exynos_chipid_variant exynos4210_chipid_drv_data = {
+	.rev_reg	= 0x0,
+	.main_rev_bit	= 0,
+	.sub_rev_bit	= 4,
+};
+
 static const struct of_device_id exynos_chipid_of_device_ids[] = {
-	{ .compatible = "samsung,exynos4210-chipid" },
-	{}
+	{
+		.compatible	= "samsung,exynos4210-chipid",
+		.data		= &exynos4210_chipid_drv_data,
+	},
+	{ }
 };
 
 static struct platform_driver exynos_chipid_driver = {
diff --git a/include/linux/soc/samsung/exynos-chipid.h b/include/linux/soc/samsung/exynos-chipid.h
index 8bca6763f99c..5270725ba408 100644
--- a/include/linux/soc/samsung/exynos-chipid.h
+++ b/include/linux/soc/samsung/exynos-chipid.h
@@ -9,10 +9,8 @@
 #define __LINUX_SOC_EXYNOS_CHIPID_H
 
 #define EXYNOS_CHIPID_REG_PRO_ID	0x00
-#define EXYNOS_SUBREV_MASK		(0xf << 4)
-#define EXYNOS_MAINREV_MASK		(0xf << 0)
-#define EXYNOS_REV_MASK			(EXYNOS_SUBREV_MASK | \
-					 EXYNOS_MAINREV_MASK)
+#define EXYNOS_REV_PART_LEN		0xf
+#define EXYNOS_REV_PART_OFF		4
 #define EXYNOS_MASK			0xfffff000
 
 #define EXYNOS_CHIPID_REG_PKG_ID	0x04
-- 
2.30.2