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/*
* 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);
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 devm_mbox_controller_register(dev, &priv->mbox);
}
static int imx_mu_remove(struct platform_device *pdev)
{
struct imx_mu_priv *priv = platform_get_drvdata(pdev);
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");
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