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can: sun4i_can: add support for R40 CAN controller

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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.

Link: https://lore.kernel.org/all/20211122104616.537156-3-boger@wirenboard.com
Signed-off-by: Evgeny Boger <boger@wirenboard.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This commit is contained in:
Evgeny Boger 2021-11-22 13:46:15 +03:00 committed by Marc Kleine-Budde
parent d0342ceb78
commit 2c2fd0e68d
1 changed files with 60 additions and 2 deletions
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62
drivers/net/can/sun4i_can.c
View File

@ -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);
@ -750,9 +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
}, {
/* sentinel */
},
};
MODULE_DEVICE_TABLE(of, sun4ican_of_match);
@ -771,10 +810,28 @@ 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 +875,7 @@ 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);