Commit 2c2fd0e6 authored by Evgeny Boger's avatar Evgeny Boger Committed by Marc Kleine-Budde
Browse files

can: sun4i_can: add support for R40 CAN controller 

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: default avatarEvgeny Boger <boger@wirenboard.com>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent d0342ceb

drivers/net/can/sun4i_can.c

+60 −2
Original line number Diff line number Diff line
@@ -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);