|  | // 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"); |