linux/drivers/mailbox/imx-mailbox.c
Peng Fan 0a67003b19 mailbox: imx: add SCU MU support
i.MX8/8X SCU MU is dedicated for communication between SCU and Cortex-A
cores from hardware design, and could not be reused for other purpose.

Per i.MX8/8X Reference mannual, Chapter "12.9.2.3.2 Messaging Examples",
 Passing short messages: Transmit register(s) can be used to pass
 short messages from one to four words in length. For example, when
 a four-word message is desired, only one of the registers needs to
 have its corresponding interrupt enable bit set at the receiver side;
 the message’s first three words are written to the registers whose
 interrupt is masked, and the fourth word is written to the other
 register (which triggers an interrupt at the receiver side).

i.MX8/8X SCU firmware IPC is an implementation of passing short
messages. But current imx-mailbox driver only support one word
message, i.MX8/8X linux side firmware has to request four TX
and four RX to support IPC to SCU firmware. This is low efficent
and more interrupts triggered compared with one TX and
one RX.

To make SCU MU work,
  - parse the size of msg.
  - Only enable TR0/RR0 interrupt for transmit/receive message.
  - For TX/RX, only support one TX channel and one RX channel
  - For RX, support receive msg larger than 4 u32 words.
  - Support 6 channels, TX0/RX0/RXDB[0-3], not support TXDB.

Reviewed-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
2020-03-19 23:04:32 -05:00

574 lines
13 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2018 Pengutronix, Oleksij Rempel <o.rempel@pengutronix.de>
*/
#include <linux/clk.h>
#include <linux/firmware/imx/ipc.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/kernel.h>
#include <linux/mailbox_controller.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/slab.h>
#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)
/* 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
/* TX0/RX0/RXDB[0-3] */
#define IMX_MU_SCU_CHANS 6
#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_sc_rpc_msg_max {
struct imx_sc_rpc_msg hdr;
u32 data[7];
};
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];
const struct imx_mu_dcfg *dcfg;
struct clk *clk;
int irq;
bool side_b;
};
struct imx_mu_dcfg {
int (*tx)(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp, void *data);
int (*rx)(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp);
void (*init)(struct imx_mu_priv *priv);
u32 xTR[4]; /* Transmit Registers */
u32 xRR[4]; /* Receive Registers */
u32 xSR; /* Status Register */
u32 xCR; /* Control Register */
};
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, priv->dcfg->xCR);
val &= ~clr;
val |= set;
imx_mu_write(priv, val, priv->dcfg->xCR);
spin_unlock_irqrestore(&priv->xcr_lock, flags);
return val;
}
static int imx_mu_generic_tx(struct imx_mu_priv *priv,
struct imx_mu_con_priv *cp,
void *data)
{
u32 *arg = data;
switch (cp->type) {
case IMX_MU_TYPE_TX:
imx_mu_write(priv, *arg, priv->dcfg->xTR[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_generic_rx(struct imx_mu_priv *priv,
struct imx_mu_con_priv *cp)
{
u32 dat;
dat = imx_mu_read(priv, priv->dcfg->xRR[cp->idx]);
mbox_chan_received_data(cp->chan, (void *)&dat);
return 0;
}
static int imx_mu_scu_tx(struct imx_mu_priv *priv,
struct imx_mu_con_priv *cp,
void *data)
{
struct imx_sc_rpc_msg_max *msg = data;
u32 *arg = data;
int i, ret;
u32 xsr;
switch (cp->type) {
case IMX_MU_TYPE_TX:
if (msg->hdr.size > sizeof(*msg)) {
/*
* The real message size can be different to
* struct imx_sc_rpc_msg_max size
*/
dev_err(priv->dev, "Exceed max msg size (%zu) on TX, got: %i\n", sizeof(*msg), msg->hdr.size);
return -EINVAL;
}
for (i = 0; i < 4 && i < msg->hdr.size; i++)
imx_mu_write(priv, *arg++, priv->dcfg->xTR[i % 4]);
for (; i < msg->hdr.size; i++) {
ret = readl_poll_timeout(priv->base + priv->dcfg->xSR,
xsr,
xsr & IMX_MU_xSR_TEn(i % 4),
0, 100);
if (ret) {
dev_err(priv->dev, "Send data index: %d timeout\n", i);
return ret;
}
imx_mu_write(priv, *arg++, priv->dcfg->xTR[i % 4]);
}
imx_mu_xcr_rmw(priv, IMX_MU_xCR_TIEn(cp->idx), 0);
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_scu_rx(struct imx_mu_priv *priv,
struct imx_mu_con_priv *cp)
{
struct imx_sc_rpc_msg_max msg;
u32 *data = (u32 *)&msg;
int i, ret;
u32 xsr;
imx_mu_xcr_rmw(priv, 0, IMX_MU_xCR_RIEn(0));
*data++ = imx_mu_read(priv, priv->dcfg->xRR[0]);
if (msg.hdr.size > sizeof(msg)) {
dev_err(priv->dev, "Exceed max msg size (%zu) on RX, got: %i\n",
sizeof(msg), msg.hdr.size);
return -EINVAL;
}
for (i = 1; i < msg.hdr.size; i++) {
ret = readl_poll_timeout(priv->base + priv->dcfg->xSR, xsr,
xsr & IMX_MU_xSR_RFn(i % 4), 0, 100);
if (ret) {
dev_err(priv->dev, "timeout read idx %d\n", i);
return ret;
}
*data++ = imx_mu_read(priv, priv->dcfg->xRR[i % 4]);
}
imx_mu_xcr_rmw(priv, IMX_MU_xCR_RIEn(0), 0);
mbox_chan_received_data(cp->chan, (void *)&msg);
return 0;
}
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;
ctrl = imx_mu_read(priv, priv->dcfg->xCR);
val = imx_mu_read(priv, priv->dcfg->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)) {
priv->dcfg->rx(priv, cp);
} else if (val == IMX_MU_xSR_GIPn(cp->idx)) {
imx_mu_write(priv, IMX_MU_xSR_GIPn(cp->idx), priv->dcfg->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;
return priv->dcfg->tx(priv, cp, data);
}
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 |
IRQF_NO_SUSPEND, 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;
}
switch (cp->type) {
case IMX_MU_TYPE_TX:
imx_mu_xcr_rmw(priv, 0, IMX_MU_xCR_TIEn(cp->idx));
break;
case IMX_MU_TYPE_RX:
imx_mu_xcr_rmw(priv, 0, IMX_MU_xCR_RIEn(cp->idx));
break;
case IMX_MU_TYPE_RXDB:
imx_mu_xcr_rmw(priv, 0, IMX_MU_xCR_GIEn(cp->idx));
break;
default:
break;
}
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_scu_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 */
switch (type) {
case IMX_MU_TYPE_TX:
case IMX_MU_TYPE_RX:
if (idx != 0)
dev_err(mbox->dev, "Invalid chan idx: %d\n", idx);
chan = type;
break;
case IMX_MU_TYPE_RXDB:
chan = 2 + idx;
break;
default:
dev_err(mbox->dev, "Invalid chan type: %d\n", type);
return NULL;
}
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 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)
{
unsigned int i;
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->mbox.num_chans = IMX_MU_CHANS;
priv->mbox.of_xlate = imx_mu_xlate;
if (priv->side_b)
return;
/* Set default MU configuration */
imx_mu_write(priv, 0, priv->dcfg->xCR);
}
static void imx_mu_init_scu(struct imx_mu_priv *priv)
{
unsigned int i;
for (i = 0; i < IMX_MU_SCU_CHANS; i++) {
struct imx_mu_con_priv *cp = &priv->con_priv[i];
cp->idx = i < 2 ? 0 : i - 2;
cp->type = i < 2 ? i : IMX_MU_TYPE_RXDB;
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->mbox.num_chans = IMX_MU_SCU_CHANS;
priv->mbox.of_xlate = imx_mu_scu_xlate;
/* Set default MU configuration */
imx_mu_write(priv, 0, priv->dcfg->xCR);
}
static int imx_mu_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
struct imx_mu_priv *priv;
const struct imx_mu_dcfg *dcfg;
int ret;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->dev = dev;
priv->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(priv->base))
return PTR_ERR(priv->base);
priv->irq = platform_get_irq(pdev, 0);
if (priv->irq < 0)
return priv->irq;
dcfg = of_device_get_match_data(dev);
if (!dcfg)
return -EINVAL;
priv->dcfg = dcfg;
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;
}
priv->side_b = of_property_read_bool(np, "fsl,mu-side-b");
priv->dcfg->init(priv);
spin_lock_init(&priv->xcr_lock);
priv->mbox.dev = dev;
priv->mbox.ops = &imx_mu_ops;
priv->mbox.chans = priv->mbox_chans;
priv->mbox.txdone_irq = true;
platform_set_drvdata(pdev, 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 imx_mu_dcfg imx_mu_cfg_imx6sx = {
.tx = imx_mu_generic_tx,
.rx = imx_mu_generic_rx,
.init = imx_mu_init_generic,
.xTR = {0x0, 0x4, 0x8, 0xc},
.xRR = {0x10, 0x14, 0x18, 0x1c},
.xSR = 0x20,
.xCR = 0x24,
};
static const struct imx_mu_dcfg imx_mu_cfg_imx7ulp = {
.tx = imx_mu_generic_tx,
.rx = imx_mu_generic_rx,
.init = imx_mu_init_generic,
.xTR = {0x20, 0x24, 0x28, 0x2c},
.xRR = {0x40, 0x44, 0x48, 0x4c},
.xSR = 0x60,
.xCR = 0x64,
};
static const struct imx_mu_dcfg imx_mu_cfg_imx8_scu = {
.tx = imx_mu_scu_tx,
.rx = imx_mu_scu_rx,
.init = imx_mu_init_scu,
.xTR = {0x0, 0x4, 0x8, 0xc},
.xRR = {0x10, 0x14, 0x18, 0x1c},
.xSR = 0x20,
.xCR = 0x24,
};
static const struct of_device_id imx_mu_dt_ids[] = {
{ .compatible = "fsl,imx7ulp-mu", .data = &imx_mu_cfg_imx7ulp },
{ .compatible = "fsl,imx6sx-mu", .data = &imx_mu_cfg_imx6sx },
{ .compatible = "fsl,imx8-mu-scu", .data = &imx_mu_cfg_imx8_scu },
{ },
};
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");