The SJA1000 CAN controller on RZ/N1 SoC has no clock divider register
(CDR) support compared to others.
This patch adds support for RZ/N1 SJA1000 CAN Controller, by adding
SoC specific compatible to handle this difference as well as using
clk framework to retrieve the CAN clock frequency.
Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
---
v3->v4:
* Updated commit description.
* Updated clock handling as per bindings.
v2->v3:
* No change.
v1->v2:
* Updated commit description as SJA1000_NO_HW_LOOPBACK_QUIRK is removed
* Added error handling on clk error path
* Started using "devm_clk_get_optional_enabled" for clk get,prepare and enable.
---
drivers/net/can/sja1000/sja1000_platform.c | 38 +++++++++++++++++++---
1 file changed, 33 insertions(+), 5 deletions(-)
diff --git a/drivers/net/can/sja1000/sja1000_platform.c b/drivers/net/can/sja1000/sja1000_platform.c
index 81bc741905fd..6779d5357069 100644
--- a/drivers/net/can/sja1000/sja1000_platform.c
+++ b/drivers/net/can/sja1000/sja1000_platform.c
@@ -14,6 +14,7 @@
#include <linux/irq.h>
#include <linux/can/dev.h>
#include <linux/can/platform/sja1000.h>
+#include <linux/clk.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_device.h>
@@ -103,6 +104,11 @@ static void sp_technologic_init(struct sja1000_priv *priv, struct device_node *o
spin_lock_init(&tp->io_lock);
}
+static void sp_rzn1_init(struct sja1000_priv *priv, struct device_node *of)
+{
+ priv->flags = SJA1000_QUIRK_NO_CDR_REG;
+}
+
static void sp_populate(struct sja1000_priv *priv,
struct sja1000_platform_data *pdata,
unsigned long resource_mem_flags)
@@ -153,11 +159,13 @@ static void sp_populate_of(struct sja1000_priv *priv, struct device_node *of)
priv->write_reg = sp_write_reg8;
}
- err = of_property_read_u32(of, "nxp,external-clock-frequency", &prop);
- if (!err)
- priv->can.clock.freq = prop / 2;
- else
- priv->can.clock.freq = SP_CAN_CLOCK; /* default */
+ if (!priv->can.clock.freq) {
+ err = of_property_read_u32(of, "nxp,external-clock-frequency", &prop);
+ if (!err)
+ priv->can.clock.freq = prop / 2;
+ else
+ priv->can.clock.freq = SP_CAN_CLOCK; /* default */
+ }
err = of_property_read_u32(of, "nxp,tx-output-mode", &prop);
if (!err)
@@ -192,8 +200,13 @@ static struct sja1000_of_data technologic_data = {
.init = sp_technologic_init,
};
+static struct sja1000_of_data renesas_data = {
+ .init = sp_rzn1_init,
+};
+
static const struct of_device_id sp_of_table[] = {
{ .compatible = "nxp,sja1000", .data = NULL, },
+ { .compatible = "renesas,rzn1-sja1000", .data = &renesas_data, },
{ .compatible = "technologic,sja1000", .data = &technologic_data, },
{ /* sentinel */ },
};
@@ -210,6 +223,7 @@ static int sp_probe(struct platform_device *pdev)
struct device_node *of = pdev->dev.of_node;
const struct sja1000_of_data *of_data = NULL;
size_t priv_sz = 0;
+ struct clk *clk;
pdata = dev_get_platdata(&pdev->dev);
if (!pdata && !of) {
@@ -234,6 +248,11 @@ static int sp_probe(struct platform_device *pdev)
irq = platform_get_irq(pdev, 0);
if (irq < 0)
return irq;
+
+ clk = devm_clk_get_optional_enabled(&pdev->dev, NULL);
+ if (IS_ERR(clk))
+ return dev_err_probe(&pdev->dev, PTR_ERR(clk),
+ "CAN clk operation failed");
} else {
res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
if (!res_irq)
@@ -262,6 +281,15 @@ static int sp_probe(struct platform_device *pdev)
priv->reg_base = addr;
if (of) {
+ if (clk) {
+ priv->can.clock.freq = clk_get_rate(clk) / 2;
+ if (!priv->can.clock.freq) {
+ err = -EINVAL;
+ dev_err(&pdev->dev, "Zero CAN clk rate");
+ goto exit_free;
+ }
+ }
+
sp_populate_of(priv, of);
if (of_data && of_data->init)
--
2.25.1
