[PATCH 3/4] hwspinlock: qcom: Allow mmio usage in addition to syscon

[Bjorn Andersson]

In all modern Qualcomm platforms the mutex region of the TCSR is forked
off into its own block, all with a offset of 0 and stride of 4096. So
add support for directly memory mapping this register space, to avoid
the need to represent this block using a syscon.

Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
---
 drivers/hwspinlock/qcom_hwspinlock.c | 72 +++++++++++++++++++++-------
 1 file changed, 56 insertions(+), 16 deletions(-)

diff --git a/drivers/hwspinlock/qcom_hwspinlock.c b/drivers/hwspinlock/qcom_hwspinlock.c
index f0da544b14d2..d8d4d729816c 100644
--- a/drivers/hwspinlock/qcom_hwspinlock.c
+++ b/drivers/hwspinlock/qcom_hwspinlock.c
@@ -70,41 +70,81 @@ static const struct of_device_id qcom_hwspinlock_of_match[] = {
 };
 MODULE_DEVICE_TABLE(of, qcom_hwspinlock_of_match);
 
-static int qcom_hwspinlock_probe(struct platform_device *pdev)
+static struct regmap *qcom_hwspinlock_probe_syscon(struct platform_device *pdev,
+						   u32 *base, u32 *stride)
 {
-	struct hwspinlock_device *bank;
 	struct device_node *syscon;
-	struct reg_field field;
 	struct regmap *regmap;
-	size_t array_size;
-	u32 stride;
-	u32 base;
 	int ret;
-	int i;
 
 	syscon = of_parse_phandle(pdev->dev.of_node, "syscon", 0);
-	if (!syscon) {
-		dev_err(&pdev->dev, "no syscon property\n");
-		return -ENODEV;
-	}
+	if (!syscon)
+		return ERR_PTR(-ENODEV);
 
 	regmap = syscon_node_to_regmap(syscon);
 	of_node_put(syscon);
 	if (IS_ERR(regmap))
-		return PTR_ERR(regmap);
+		return regmap;
 
-	ret = of_property_read_u32_index(pdev->dev.of_node, "syscon", 1, &base);
+	ret = of_property_read_u32_index(pdev->dev.of_node, "syscon", 1, base);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "no offset in syscon\n");
-		return -EINVAL;
+		return ERR_PTR(-EINVAL);
 	}
 
-	ret = of_property_read_u32_index(pdev->dev.of_node, "syscon", 2, &stride);
+	ret = of_property_read_u32_index(pdev->dev.of_node, "syscon", 2, stride);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "no stride syscon\n");
-		return -EINVAL;
+		return ERR_PTR(-EINVAL);
 	}
 
+	return regmap;
+}
+
+static const struct regmap_config tcsr_mutex_config = {
+	.reg_bits		= 32,
+	.reg_stride		= 4,
+	.val_bits		= 32,
+	.max_register		= 0x40000,
+	.fast_io		= true,
+};
+
+static struct regmap *qcom_hwspinlock_probe_mmio(struct platform_device *pdev,
+						 u32 *offset, u32 *stride)
+{
+	struct device *dev = &pdev->dev;
+	struct resource *res;
+	void __iomem *base;
+
+	/* All modern platform has offset 0 and stride of 4k */
+	*offset = 0;
+	*stride = 0x1000;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(base))
+		return ERR_CAST(base);
+
+	return devm_regmap_init_mmio(dev, base, &tcsr_mutex_config);
+}
+
+static int qcom_hwspinlock_probe(struct platform_device *pdev)
+{
+	struct hwspinlock_device *bank;
+	struct reg_field field;
+	struct regmap *regmap;
+	size_t array_size;
+	u32 stride;
+	u32 base;
+	int i;
+
+	regmap = qcom_hwspinlock_probe_syscon(pdev, &base, &stride);
+	if (IS_ERR(regmap) && PTR_ERR(regmap) == -ENODEV)
+		regmap = qcom_hwspinlock_probe_mmio(pdev, &base, &stride);
+
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
 	array_size = QCOM_MUTEX_NUM_LOCKS * sizeof(struct hwspinlock);
 	bank = devm_kzalloc(&pdev->dev, sizeof(*bank) + array_size, GFP_KERNEL);
 	if (!bank)
-- 
2.26.2