From 2c2fd0e68d9e1832d7661f434ee7ddd77bf1b985 Mon Sep 17 00:00:00 2001 From: Evgeny Boger Date: Mon, 22 Nov 2021 13:46:15 +0300 Subject: 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: Evgeny Boger Signed-off-by: Marc Kleine-Budde --- drivers/net/can/sun4i_can.c | 62 +++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 60 insertions(+), 2 deletions(-) diff --git a/drivers/net/can/sun4i_can.c b/drivers/net/can/sun4i_can.c index 54aa7c25c4de..37862e7f6840 100644 --- a/drivers/net/can/sun4i_can.c +++ b/drivers/net/can/sun4i_can.c @@ -61,6 +61,7 @@ #include #include #include +#include #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); -- cgit 1.4.1