Re: [PATCH] net, can, ti_hecc: add DT support for the ti,hecc controller

From: Heiko Schocher
Date: Mon Oct 19 2015 - 03:27:30 EST

Hello Marc,

Am 19.10.2015 um 08:58 schrieb Marc Kleine-Budde:
On 10/19/2015 08:39 AM, Heiko Schocher wrote:
add DT support for the ti hecc controller, used on
am3517 SoCs.

A similar patch was posted a few days ago, see
http://comments.gmane.org/gmane.linux.can/8616 and my comments.

Uh, sorry! Seems I missed them ...

Please coordinate with Anton Glukhov (Cc'ed) and/or pick up his patches
as they are in better shape.

Yes, I try the patchset from Anton ... thanks for pointing to them.

@Anton: Do you have a newer version, which contains the comments
from Marc?

bye,
Heiko

Marc

Signed-off-by: Heiko Schocher <hs@xxxxxxx>
---

.../devicetree/bindings/net/can/ti_hecc-can.txt | 20 ++++++++++
arch/arm/boot/dts/am3517.dtsi | 13 +++++++
drivers/net/can/ti_hecc.c | 45 +++++++++++++++++++++-
3 files changed, 76 insertions(+), 2 deletions(-)
create mode 100644 Documentation/devicetree/bindings/net/can/ti_hecc-can.txt

diff --git a/Documentation/devicetree/bindings/net/can/ti_hecc-can.txt b/Documentation/devicetree/bindings/net/can/ti_hecc-can.txt
new file mode 100644
index 0000000..09fab59
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/can/ti_hecc-can.txt
@@ -0,0 +1,20 @@
+* TI HECC CAN *
+
+Required properties:
+ - compatible: Should be "ti,hecc"

We usually put the name of the first SoC this IP core appears in to the
compatible.

Ok, so "ti,am335xx-hecc" would be OK?
@Anton: you used "am35x" ... it should be "am35xx"

+ - reg: Should contain CAN controller registers location and length
+ - interrupts: Should contain IRQ line for the CAN controller

I'm missing the description of the ti,* properties. I think they are
required, too. Although the code doesn't enforce it.

Ok.

+
+Example:
+
+ can0: hecc@5c050000 {
+ compatible = "ti,hecc";
+ reg = <0x5c050000 0x4000>;
+ interrupts = <24>;
+ ti,hecc_scc_offset = <0>;
+ ti,hecc_scc_ram_offset = <0x3000>;
+ ti,hecc_ram_offset = <0x3000>;
+ ti,hecc_mbx_offset = <0x2000>;
+ ti,hecc_int_line = <0>;
+ ti,hecc_version = <1>;

Versioning in the OF world is done via the compatible. Are the offsets a
per SoC parameter? I'm not sure if it's better to put
the offsets into the driver.

I am unsure here too..

+ };
diff --git a/arch/arm/boot/dts/am3517.dtsi b/arch/arm/boot/dts/am3517.dtsi
index 5e3f5e8..47bc429 100644
--- a/arch/arm/boot/dts/am3517.dtsi
+++ b/arch/arm/boot/dts/am3517.dtsi
@@ -25,6 +25,19 @@
interrupt-names = "mc";
};

+ can0: hecc@5c050000 {
+ compatible = "ti,hecc";
+ reg = <0x5c050000 0x4000>;
+ interrupts = <24>;
+ ti,hecc_scc_offset = <0>;
+ ti,hecc_scc_ram_offset = <0x3000>;
+ ti,hecc_ram_offset = <0x3000>;
+ ti,hecc_mbx_offset = <0x2000>;
+ ti,hecc_int_line = <0>;
+ ti,hecc_version = <1>;
+ status = "disabled";
+ };
+
davinci_emac: ethernet@0x5c000000 {
compatible = "ti,am3517-emac";
ti,hwmods = "davinci_emac";
diff --git a/drivers/net/can/ti_hecc.c b/drivers/net/can/ti_hecc.c
index c08e8ea..f1705d5 100644
--- a/drivers/net/can/ti_hecc.c
+++ b/drivers/net/can/ti_hecc.c
@@ -875,16 +875,56 @@ static const struct net_device_ops ti_hecc_netdev_ops = {
.ndo_change_mtu = can_change_mtu,
};

+#if defined(CONFIG_OF)
+static const struct of_device_id ti_hecc_can_dt_ids[] = {
+ {
+ .compatible = "ti,hecc",
+ }, {
+ /* sentinel */
+ }
+};
+MODULE_DEVICE_TABLE(of, ti_hecc_can_dt_ids);
+#endif

Please remove the ifdef, use __maybe_unused instead.

+
+static const struct ti_hecc_platform_data
+*ti_hecc_can_get_driver_data(struct platform_device *pdev)
+{
+ if (pdev->dev.of_node) {
+ struct ti_hecc_platform_data *data;
+ struct device_node *np = pdev->dev.of_node;
+
+ data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return NULL;
+
+ of_property_read_u32(np, "ti,hecc_scc_offset",
+ &data->scc_hecc_offset);
+ of_property_read_u32(np, "ti,hecc_scc_ram_offset",
+ &data->scc_ram_offset);
+ of_property_read_u32(np, "ti,hecc_ram_offset",
+ &data->hecc_ram_offset);
+ of_property_read_u32(np, "ti,hecc_mbx_offset",
+ &data->mbx_offset);
+ of_property_read_u32(np, "ti,hecc_int_line",
+ &data->int_line);
+ of_property_read_u32(np, "ti,hecc_version",
+ &data->version);

I'm missing error handling here.

+ return data;
+ }
+ return (const struct ti_hecc_platform_data *)
+ dev_get_platdata(&pdev->dev);

Is this cast needed?

+}
+
static int ti_hecc_probe(struct platform_device *pdev)
{
struct net_device *ndev = (struct net_device *)0;
struct ti_hecc_priv *priv;
- struct ti_hecc_platform_data *pdata;
+ const struct ti_hecc_platform_data *pdata;
struct resource *mem, *irq;
void __iomem *addr;
int err = -ENODEV;

- pdata = dev_get_platdata(&pdev->dev);
+ pdata = ti_hecc_can_get_driver_data(pdev);
if (!pdata) {
dev_err(&pdev->dev, "No platform data\n");
goto probe_exit;
@@ -1040,6 +1080,7 @@ static int ti_hecc_resume(struct platform_device *pdev)
static struct platform_driver ti_hecc_driver = {
.driver = {
.name = DRV_NAME,
+ .of_match_table = of_match_ptr(ti_hecc_can_dt_ids),
},
.probe = ti_hecc_probe,
.remove = ti_hecc_remove,


Marc


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