| // SPDX-License-Identifier: GPL-2.0 | 
 | /* | 
 |  * Copyright (c) 2018 Pengutronix, Oleksij Rempel <o.rempel@pengutronix.de> | 
 |  */ | 
 |  | 
 | #include <linux/clk.h> | 
 | #include <linux/interrupt.h> | 
 | #include <linux/io.h> | 
 | #include <linux/kernel.h> | 
 | #include <linux/mailbox_controller.h> | 
 | #include <linux/module.h> | 
 | #include <linux/of_device.h> | 
 | #include <linux/slab.h> | 
 |  | 
 | /* Transmit Register */ | 
 | #define IMX_MU_xTRn(x)		(0x00 + 4 * (x)) | 
 | /* Receive Register */ | 
 | #define IMX_MU_xRRn(x)		(0x10 + 4 * (x)) | 
 | /* Status Register */ | 
 | #define IMX_MU_xSR		0x20 | 
 | #define IMX_MU_xSR_GIPn(x)	BIT(28 + (3 - (x))) | 
 | #define IMX_MU_xSR_RFn(x)	BIT(24 + (3 - (x))) | 
 | #define IMX_MU_xSR_TEn(x)	BIT(20 + (3 - (x))) | 
 | #define IMX_MU_xSR_BRDIP	BIT(9) | 
 |  | 
 | /* Control Register */ | 
 | #define IMX_MU_xCR		0x24 | 
 | /* General Purpose Interrupt Enable */ | 
 | #define IMX_MU_xCR_GIEn(x)	BIT(28 + (3 - (x))) | 
 | /* Receive Interrupt Enable */ | 
 | #define IMX_MU_xCR_RIEn(x)	BIT(24 + (3 - (x))) | 
 | /* Transmit Interrupt Enable */ | 
 | #define IMX_MU_xCR_TIEn(x)	BIT(20 + (3 - (x))) | 
 | /* General Purpose Interrupt Request */ | 
 | #define IMX_MU_xCR_GIRn(x)	BIT(16 + (3 - (x))) | 
 |  | 
 | #define IMX_MU_CHANS		16 | 
 | #define IMX_MU_CHAN_NAME_SIZE	20 | 
 |  | 
 | enum imx_mu_chan_type { | 
 | 	IMX_MU_TYPE_TX,		/* Tx */ | 
 | 	IMX_MU_TYPE_RX,		/* Rx */ | 
 | 	IMX_MU_TYPE_TXDB,	/* Tx doorbell */ | 
 | 	IMX_MU_TYPE_RXDB,	/* Rx doorbell */ | 
 | }; | 
 |  | 
 | struct imx_mu_con_priv { | 
 | 	unsigned int		idx; | 
 | 	char			irq_desc[IMX_MU_CHAN_NAME_SIZE]; | 
 | 	enum imx_mu_chan_type	type; | 
 | 	struct mbox_chan	*chan; | 
 | 	struct tasklet_struct	txdb_tasklet; | 
 | }; | 
 |  | 
 | struct imx_mu_priv { | 
 | 	struct device		*dev; | 
 | 	void __iomem		*base; | 
 | 	spinlock_t		xcr_lock; /* control register lock */ | 
 |  | 
 | 	struct mbox_controller	mbox; | 
 | 	struct mbox_chan	mbox_chans[IMX_MU_CHANS]; | 
 |  | 
 | 	struct imx_mu_con_priv  con_priv[IMX_MU_CHANS]; | 
 | 	struct clk		*clk; | 
 | 	int			irq; | 
 |  | 
 | 	bool			side_b; | 
 | }; | 
 |  | 
 | static struct imx_mu_priv *to_imx_mu_priv(struct mbox_controller *mbox) | 
 | { | 
 | 	return container_of(mbox, struct imx_mu_priv, mbox); | 
 | } | 
 |  | 
 | static void imx_mu_write(struct imx_mu_priv *priv, u32 val, u32 offs) | 
 | { | 
 | 	iowrite32(val, priv->base + offs); | 
 | } | 
 |  | 
 | static u32 imx_mu_read(struct imx_mu_priv *priv, u32 offs) | 
 | { | 
 | 	return ioread32(priv->base + offs); | 
 | } | 
 |  | 
 | static u32 imx_mu_xcr_rmw(struct imx_mu_priv *priv, u32 set, u32 clr) | 
 | { | 
 | 	unsigned long flags; | 
 | 	u32 val; | 
 |  | 
 | 	spin_lock_irqsave(&priv->xcr_lock, flags); | 
 | 	val = imx_mu_read(priv, IMX_MU_xCR); | 
 | 	val &= ~clr; | 
 | 	val |= set; | 
 | 	imx_mu_write(priv, val, IMX_MU_xCR); | 
 | 	spin_unlock_irqrestore(&priv->xcr_lock, flags); | 
 |  | 
 | 	return val; | 
 | } | 
 |  | 
 | static void imx_mu_txdb_tasklet(unsigned long data) | 
 | { | 
 | 	struct imx_mu_con_priv *cp = (struct imx_mu_con_priv *)data; | 
 |  | 
 | 	mbox_chan_txdone(cp->chan, 0); | 
 | } | 
 |  | 
 | static irqreturn_t imx_mu_isr(int irq, void *p) | 
 | { | 
 | 	struct mbox_chan *chan = p; | 
 | 	struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox); | 
 | 	struct imx_mu_con_priv *cp = chan->con_priv; | 
 | 	u32 val, ctrl, dat; | 
 |  | 
 | 	ctrl = imx_mu_read(priv, IMX_MU_xCR); | 
 | 	val = imx_mu_read(priv, IMX_MU_xSR); | 
 |  | 
 | 	switch (cp->type) { | 
 | 	case IMX_MU_TYPE_TX: | 
 | 		val &= IMX_MU_xSR_TEn(cp->idx) & | 
 | 			(ctrl & IMX_MU_xCR_TIEn(cp->idx)); | 
 | 		break; | 
 | 	case IMX_MU_TYPE_RX: | 
 | 		val &= IMX_MU_xSR_RFn(cp->idx) & | 
 | 			(ctrl & IMX_MU_xCR_RIEn(cp->idx)); | 
 | 		break; | 
 | 	case IMX_MU_TYPE_RXDB: | 
 | 		val &= IMX_MU_xSR_GIPn(cp->idx) & | 
 | 			(ctrl & IMX_MU_xCR_GIEn(cp->idx)); | 
 | 		break; | 
 | 	default: | 
 | 		break; | 
 | 	} | 
 |  | 
 | 	if (!val) | 
 | 		return IRQ_NONE; | 
 |  | 
 | 	if (val == IMX_MU_xSR_TEn(cp->idx)) { | 
 | 		imx_mu_xcr_rmw(priv, 0, IMX_MU_xCR_TIEn(cp->idx)); | 
 | 		mbox_chan_txdone(chan, 0); | 
 | 	} else if (val == IMX_MU_xSR_RFn(cp->idx)) { | 
 | 		dat = imx_mu_read(priv, IMX_MU_xRRn(cp->idx)); | 
 | 		mbox_chan_received_data(chan, (void *)&dat); | 
 | 	} else if (val == IMX_MU_xSR_GIPn(cp->idx)) { | 
 | 		imx_mu_write(priv, IMX_MU_xSR_GIPn(cp->idx), IMX_MU_xSR); | 
 | 		mbox_chan_received_data(chan, NULL); | 
 | 	} else { | 
 | 		dev_warn_ratelimited(priv->dev, "Not handled interrupt\n"); | 
 | 		return IRQ_NONE; | 
 | 	} | 
 |  | 
 | 	return IRQ_HANDLED; | 
 | } | 
 |  | 
 | static int imx_mu_send_data(struct mbox_chan *chan, void *data) | 
 | { | 
 | 	struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox); | 
 | 	struct imx_mu_con_priv *cp = chan->con_priv; | 
 | 	u32 *arg = data; | 
 |  | 
 | 	switch (cp->type) { | 
 | 	case IMX_MU_TYPE_TX: | 
 | 		imx_mu_write(priv, *arg, IMX_MU_xTRn(cp->idx)); | 
 | 		imx_mu_xcr_rmw(priv, IMX_MU_xCR_TIEn(cp->idx), 0); | 
 | 		break; | 
 | 	case IMX_MU_TYPE_TXDB: | 
 | 		imx_mu_xcr_rmw(priv, IMX_MU_xCR_GIRn(cp->idx), 0); | 
 | 		tasklet_schedule(&cp->txdb_tasklet); | 
 | 		break; | 
 | 	default: | 
 | 		dev_warn_ratelimited(priv->dev, "Send data on wrong channel type: %d\n", cp->type); | 
 | 		return -EINVAL; | 
 | 	} | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | static int imx_mu_startup(struct mbox_chan *chan) | 
 | { | 
 | 	struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox); | 
 | 	struct imx_mu_con_priv *cp = chan->con_priv; | 
 | 	int ret; | 
 |  | 
 | 	if (cp->type == IMX_MU_TYPE_TXDB) { | 
 | 		/* Tx doorbell don't have ACK support */ | 
 | 		tasklet_init(&cp->txdb_tasklet, imx_mu_txdb_tasklet, | 
 | 			     (unsigned long)cp); | 
 | 		return 0; | 
 | 	} | 
 |  | 
 | 	ret = request_irq(priv->irq, imx_mu_isr, IRQF_SHARED, cp->irq_desc, | 
 | 			  chan); | 
 | 	if (ret) { | 
 | 		dev_err(priv->dev, | 
 | 			"Unable to acquire IRQ %d\n", priv->irq); | 
 | 		return ret; | 
 | 	} | 
 |  | 
 | 	switch (cp->type) { | 
 | 	case IMX_MU_TYPE_RX: | 
 | 		imx_mu_xcr_rmw(priv, IMX_MU_xCR_RIEn(cp->idx), 0); | 
 | 		break; | 
 | 	case IMX_MU_TYPE_RXDB: | 
 | 		imx_mu_xcr_rmw(priv, IMX_MU_xCR_GIEn(cp->idx), 0); | 
 | 		break; | 
 | 	default: | 
 | 		break; | 
 | 	} | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | static void imx_mu_shutdown(struct mbox_chan *chan) | 
 | { | 
 | 	struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox); | 
 | 	struct imx_mu_con_priv *cp = chan->con_priv; | 
 |  | 
 | 	if (cp->type == IMX_MU_TYPE_TXDB) { | 
 | 		tasklet_kill(&cp->txdb_tasklet); | 
 | 		return; | 
 | 	} | 
 |  | 
 | 	imx_mu_xcr_rmw(priv, 0, | 
 | 		   IMX_MU_xCR_TIEn(cp->idx) | IMX_MU_xCR_RIEn(cp->idx)); | 
 |  | 
 | 	free_irq(priv->irq, chan); | 
 | } | 
 |  | 
 | static const struct mbox_chan_ops imx_mu_ops = { | 
 | 	.send_data = imx_mu_send_data, | 
 | 	.startup = imx_mu_startup, | 
 | 	.shutdown = imx_mu_shutdown, | 
 | }; | 
 |  | 
 | static struct mbox_chan * imx_mu_xlate(struct mbox_controller *mbox, | 
 | 				       const struct of_phandle_args *sp) | 
 | { | 
 | 	u32 type, idx, chan; | 
 |  | 
 | 	if (sp->args_count != 2) { | 
 | 		dev_err(mbox->dev, "Invalid argument count %d\n", sp->args_count); | 
 | 		return ERR_PTR(-EINVAL); | 
 | 	} | 
 |  | 
 | 	type = sp->args[0]; /* channel type */ | 
 | 	idx = sp->args[1]; /* index */ | 
 | 	chan = type * 4 + idx; | 
 |  | 
 | 	if (chan >= mbox->num_chans) { | 
 | 		dev_err(mbox->dev, "Not supported channel number: %d. (type: %d, idx: %d)\n", chan, type, idx); | 
 | 		return ERR_PTR(-EINVAL); | 
 | 	} | 
 |  | 
 | 	return &mbox->chans[chan]; | 
 | } | 
 |  | 
 | static void imx_mu_init_generic(struct imx_mu_priv *priv) | 
 | { | 
 | 	if (priv->side_b) | 
 | 		return; | 
 |  | 
 | 	/* Set default MU configuration */ | 
 | 	imx_mu_write(priv, 0, IMX_MU_xCR); | 
 | } | 
 |  | 
 | static int imx_mu_probe(struct platform_device *pdev) | 
 | { | 
 | 	struct device *dev = &pdev->dev; | 
 | 	struct device_node *np = dev->of_node; | 
 | 	struct resource *iomem; | 
 | 	struct imx_mu_priv *priv; | 
 | 	unsigned int i; | 
 | 	int ret; | 
 |  | 
 | 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); | 
 | 	if (!priv) | 
 | 		return -ENOMEM; | 
 |  | 
 | 	priv->dev = dev; | 
 |  | 
 | 	iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0); | 
 | 	priv->base = devm_ioremap_resource(&pdev->dev, iomem); | 
 | 	if (IS_ERR(priv->base)) | 
 | 		return PTR_ERR(priv->base); | 
 |  | 
 | 	priv->irq = platform_get_irq(pdev, 0); | 
 | 	if (priv->irq < 0) | 
 | 		return priv->irq; | 
 |  | 
 | 	priv->clk = devm_clk_get(dev, NULL); | 
 | 	if (IS_ERR(priv->clk)) { | 
 | 		if (PTR_ERR(priv->clk) != -ENOENT) | 
 | 			return PTR_ERR(priv->clk); | 
 |  | 
 | 		priv->clk = NULL; | 
 | 	} | 
 |  | 
 | 	ret = clk_prepare_enable(priv->clk); | 
 | 	if (ret) { | 
 | 		dev_err(dev, "Failed to enable clock\n"); | 
 | 		return ret; | 
 | 	} | 
 |  | 
 | 	for (i = 0; i < IMX_MU_CHANS; i++) { | 
 | 		struct imx_mu_con_priv *cp = &priv->con_priv[i]; | 
 |  | 
 | 		cp->idx = i % 4; | 
 | 		cp->type = i >> 2; | 
 | 		cp->chan = &priv->mbox_chans[i]; | 
 | 		priv->mbox_chans[i].con_priv = cp; | 
 | 		snprintf(cp->irq_desc, sizeof(cp->irq_desc), | 
 | 			 "imx_mu_chan[%i-%i]", cp->type, cp->idx); | 
 | 	} | 
 |  | 
 | 	priv->side_b = of_property_read_bool(np, "fsl,mu-side-b"); | 
 |  | 
 | 	spin_lock_init(&priv->xcr_lock); | 
 |  | 
 | 	priv->mbox.dev = dev; | 
 | 	priv->mbox.ops = &imx_mu_ops; | 
 | 	priv->mbox.chans = priv->mbox_chans; | 
 | 	priv->mbox.num_chans = IMX_MU_CHANS; | 
 | 	priv->mbox.of_xlate = imx_mu_xlate; | 
 | 	priv->mbox.txdone_irq = true; | 
 |  | 
 | 	platform_set_drvdata(pdev, priv); | 
 |  | 
 | 	imx_mu_init_generic(priv); | 
 |  | 
 | 	return mbox_controller_register(&priv->mbox); | 
 | } | 
 |  | 
 | static int imx_mu_remove(struct platform_device *pdev) | 
 | { | 
 | 	struct imx_mu_priv *priv = platform_get_drvdata(pdev); | 
 |  | 
 | 	mbox_controller_unregister(&priv->mbox); | 
 | 	clk_disable_unprepare(priv->clk); | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | static const struct of_device_id imx_mu_dt_ids[] = { | 
 | 	{ .compatible = "fsl,imx6sx-mu" }, | 
 | 	{ }, | 
 | }; | 
 | MODULE_DEVICE_TABLE(of, imx_mu_dt_ids); | 
 |  | 
 | static struct platform_driver imx_mu_driver = { | 
 | 	.probe		= imx_mu_probe, | 
 | 	.remove		= imx_mu_remove, | 
 | 	.driver = { | 
 | 		.name	= "imx_mu", | 
 | 		.of_match_table = imx_mu_dt_ids, | 
 | 	}, | 
 | }; | 
 | module_platform_driver(imx_mu_driver); | 
 |  | 
 | MODULE_AUTHOR("Oleksij Rempel <o.rempel@pengutronix.de>"); | 
 | MODULE_DESCRIPTION("Message Unit driver for i.MX"); | 
 | MODULE_LICENSE("GPL v2"); |