[PATCH 1/3][can-next] can: rcar_can: Fix erroneous registration

[Fabrizio Castro <fabrizio.castro@bp.renesas.com>]

Assigning 2 to "renesas,can-clock-select" tricks the driver into
registering the CAN interface, even though we don't want that.
This patch fixes this problem and also allows for architectures
missing some of the clocks (e.g. RZ/G2) to behave as expected.

Fixes: 862e2b6af9413b43 ("can: rcar_can: support all input clocks")
Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Signed-off-by: Chris Paterson <Chris.Paterson2@renesas.com>
---

This patch applies on linux-can-next-for-4.19-20180727

 drivers/net/can/rcar/rcar_can.c | 43 +++++++++++++++++++++++++++++++++--------
 1 file changed, 35 insertions(+), 8 deletions(-)

diff --git a/drivers/net/can/rcar/rcar_can.c b/drivers/net/can/rcar/rcar_can.c
index 11662f4..fbd9284 100644
--- a/drivers/net/can/rcar/rcar_can.c
+++ b/drivers/net/can/rcar/rcar_can.c
@@ -21,9 +21,13 @@
 #include <linux/clk.h>
 #include <linux/can/platform/rcar_can.h>
 #include <linux/of.h>
+#include <linux/of_device.h>
 
 #define RCAR_CAN_DRV_NAME	"rcar_can"
 
+#define RCAR_SUPPORTED_CLOCKS	(BIT(CLKR_CLKP1) | BIT(CLKR_CLKP2) | \
+				 BIT(CLKR_CLKEXT))
+
 /* Mailbox configuration:
  * mailbox 60 - 63 - Rx FIFO mailboxes
  * mailbox 56 - 59 - Tx FIFO mailboxes
@@ -745,10 +749,12 @@ static int rcar_can_probe(struct platform_device *pdev)
 	u32 clock_select = CLKR_CLKP1;
 	int err = -ENODEV;
 	int irq;
+	uintptr_t allowed_clks = RCAR_SUPPORTED_CLOCKS;
 
 	if (pdev->dev.of_node) {
 		of_property_read_u32(pdev->dev.of_node,
 				     "renesas,can-clock-select", &clock_select);
+		allowed_clks = (uintptr_t)of_device_get_match_data(&pdev->dev);
 	} else {
 		pdata = dev_get_platdata(&pdev->dev);
 		if (!pdata) {
@@ -789,7 +795,7 @@ static int rcar_can_probe(struct platform_device *pdev)
 		goto fail_clk;
 	}
 
-	if (clock_select >= ARRAY_SIZE(clock_names)) {
+	if (!(BIT(clock_select) & allowed_clks)) {
 		err = -EINVAL;
 		dev_err(&pdev->dev, "invalid CAN clock selected\n");
 		goto fail_clk;
@@ -899,13 +905,34 @@ static int __maybe_unused rcar_can_resume(struct device *dev)
 static SIMPLE_DEV_PM_OPS(rcar_can_pm_ops, rcar_can_suspend, rcar_can_resume);
 
 static const struct of_device_id rcar_can_of_table[] __maybe_unused = {
-	{ .compatible = "renesas,can-r8a7778" },
-	{ .compatible = "renesas,can-r8a7779" },
-	{ .compatible = "renesas,can-r8a7790" },
-	{ .compatible = "renesas,can-r8a7791" },
-	{ .compatible = "renesas,rcar-gen1-can" },
-	{ .compatible = "renesas,rcar-gen2-can" },
-	{ .compatible = "renesas,rcar-gen3-can" },
+	{
+		.compatible = "renesas,can-r8a7778",
+		.data = (void *)RCAR_SUPPORTED_CLOCKS,
+	},
+	{
+		.compatible = "renesas,can-r8a7779",
+		.data = (void *)RCAR_SUPPORTED_CLOCKS,
+	},
+	{
+		.compatible = "renesas,can-r8a7790",
+		.data = (void *)RCAR_SUPPORTED_CLOCKS,
+	},
+	{
+		.compatible = "renesas,can-r8a7791",
+		.data = (void *)RCAR_SUPPORTED_CLOCKS,
+	},
+	{
+		.compatible = "renesas,rcar-gen1-can",
+		.data = (void *)RCAR_SUPPORTED_CLOCKS,
+	},
+	{
+		.compatible = "renesas,rcar-gen2-can",
+		.data = (void *)RCAR_SUPPORTED_CLOCKS,
+	},
+	{
+		.compatible = "renesas,rcar-gen3-can",
+		.data = (void *)RCAR_SUPPORTED_CLOCKS,
+	},
 	{ }
 };
 MODULE_DEVICE_TABLE(of, rcar_can_of_table);
-- 
2.7.4