From: Evgeny Boger <boger@wirenboard.com>
To: Maxime Ripard <mripard@kernel.org>, Chen-Yu Tsai <wens@csie.org>,
linux-arm-kernel@lists.infradead.org
Cc: Evgeny Boger <boger@wirenboard.com>,
devicetree@vger.kernel.org, linux-sunxi@lists.linux.dev,
linux-can@vger.kernel.org,
Wolfgang Grandegger <wg@grandegger.com>,
Marc Kleine-Budde <mkl@pengutronix.de>,
"David S . Miller" <davem@davemloft.net>,
Jeroen Hofstee <jhofstee@victronenergy.com>,
Gerhard Bertelsmann <info@gerhard-bertelsmann.de>
Subject: [PATCH 2/3] can: sun4i_can: add support for R40 CAN controller
Date: Mon, 22 Nov 2021 13:46:15 +0300 [thread overview]
Message-ID: <20211122104616.537156-3-boger@wirenboard.com> (raw)
In-Reply-To: <20211122104616.537156-1-boger@wirenboard.com>
Allwinner R40 (also known as A40i, T3, V40) has a CAN controller. The
controller is the same as in earlier A10 and A20 SoCs, but needs reset
line to be deasserted before use.
This patch adds a new compatible for R40 CAN controller. Depending
on the compatible, reset line can be requested from DT.
Signed-off-by: Evgeny Boger <boger@wirenboard.com>
---
drivers/net/can/sun4i_can.c | 61 ++++++++++++++++++++++++++++++++++++-
1 file changed, 60 insertions(+), 1 deletion(-)
diff --git a/drivers/net/can/sun4i_can.c b/drivers/net/can/sun4i_can.c
index 54aa7c25c4de..24a61326915e 100644
--- a/drivers/net/can/sun4i_can.c
+++ b/drivers/net/can/sun4i_can.c
@@ -61,6 +61,7 @@
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
+#include <linux/reset.h>
#define DRV_NAME "sun4i_can"
@@ -200,10 +201,20 @@
#define SUN4I_CAN_MAX_IRQ 20
#define SUN4I_MODE_MAX_RETRIES 100
+/**
+ * struct sun4ican_quirks - Differences between SoC variants.
+ *
+ * @has_reset: SoC needs reset deasserted.
+ */
+struct sun4ican_quirks {
+ bool has_reset;
+};
+
struct sun4ican_priv {
struct can_priv can;
void __iomem *base;
struct clk *clk;
+ struct reset_control *reset;
spinlock_t cmdreg_lock; /* lock for concurrent cmd register writes */
};
@@ -702,6 +713,13 @@ static int sun4ican_open(struct net_device *dev)
goto exit_irq;
}
+ /* software reset deassert */
+ err = reset_control_deassert(priv->reset);
+ if (err) {
+ netdev_err(dev, "could not deassert CAN reset\n");
+ goto exit_soft_reset;
+ }
+
/* turn on clocking for CAN peripheral block */
err = clk_prepare_enable(priv->clk);
if (err) {
@@ -723,6 +741,8 @@ static int sun4ican_open(struct net_device *dev)
exit_can_start:
clk_disable_unprepare(priv->clk);
exit_clock:
+ reset_control_assert(priv->reset);
+exit_soft_reset:
free_irq(dev->irq, dev);
exit_irq:
close_candev(dev);
@@ -736,6 +756,7 @@ static int sun4ican_close(struct net_device *dev)
netif_stop_queue(dev);
sun4i_can_stop(dev);
clk_disable_unprepare(priv->clk);
+ reset_control_assert(priv->reset);
free_irq(dev->irq, dev);
close_candev(dev);
@@ -750,8 +771,27 @@ static const struct net_device_ops sun4ican_netdev_ops = {
.ndo_start_xmit = sun4ican_start_xmit,
};
+static const struct sun4ican_quirks sun4ican_quirks_a10 = {
+ .has_reset = false,
+};
+
+static const struct sun4ican_quirks sun4ican_quirks_r40 = {
+ .has_reset = true,
+};
+
static const struct of_device_id sun4ican_of_match[] = {
- {.compatible = "allwinner,sun4i-a10-can"},
+ {
+ .compatible = "allwinner,sun4i-a10-can",
+ .data = &sun4ican_quirks_a10
+ },
+ {
+ .compatible = "allwinner,sun7i-a20-can",
+ .data = &sun4ican_quirks_a10
+ },
+ {
+ .compatible = "allwinner,sun8i-r40-can",
+ .data = &sun4ican_quirks_r40
+ },
{},
};
@@ -771,10 +811,28 @@ static int sun4ican_probe(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
struct clk *clk;
+ struct reset_control *reset = NULL;
void __iomem *addr;
int err, irq;
struct net_device *dev;
struct sun4ican_priv *priv;
+ const struct sun4ican_quirks *quirks;
+
+ quirks = of_device_get_match_data(&pdev->dev);
+ if (!quirks) {
+ dev_err(&pdev->dev, "failed to determine the quirks to use\n");
+ err = -ENODEV;
+ goto exit;
+ }
+
+ if (quirks->has_reset) {
+ reset = devm_reset_control_get_exclusive(&pdev->dev, NULL);
+ if (IS_ERR(reset)) {
+ dev_err(&pdev->dev, "unable to request reset\n");
+ err = PTR_ERR(reset);
+ goto exit;
+ }
+ }
clk = of_clk_get(np, 0);
if (IS_ERR(clk)) {
@@ -818,6 +876,7 @@ static int sun4ican_probe(struct platform_device *pdev)
CAN_CTRLMODE_3_SAMPLES;
priv->base = addr;
priv->clk = clk;
+ priv->reset = reset;
spin_lock_init(&priv->cmdreg_lock);
platform_set_drvdata(pdev, dev);
--
2.25.1
next prev parent reply other threads:[~2021-11-22 10:46 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-22 10:46 [PATCH 0/3] add support for Allwinner R40 CAN controller Evgeny Boger
2021-11-22 10:46 ` [PATCH 1/3] dt-bindings: net: can: " Evgeny Boger
2021-11-30 2:25 ` Rob Herring
2021-11-22 10:46 ` Evgeny Boger [this message]
2021-11-22 10:46 ` [PATCH 3/3] ARM: dts: sun8i: r40: add node for " Evgeny Boger
2021-11-22 10:56 ` Maxime Ripard
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