diff options
Diffstat (limited to 'drivers/mailbox/imx-mailbox.c')
-rw-r--r-- | drivers/mailbox/imx-mailbox.c | 360 |
1 files changed, 360 insertions, 0 deletions
diff --git a/drivers/mailbox/imx-mailbox.c b/drivers/mailbox/imx-mailbox.c new file mode 100644 index 000000000..2f47023ca --- /dev/null +++ b/drivers/mailbox/imx-mailbox.c @@ -0,0 +1,360 @@ +// 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"); |