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linux_kernel/drivers/mailbox/mailbox-altera.c
Thomas Gleixner 9952f6918d treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 201 
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms and conditions of the gnu general public license
  version 2 as published by the free software foundation this program
  is distributed in the hope it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details you should have received a copy of the gnu general
  public license along with this program if not see http www gnu org
  licenses

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 228 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Steve Winslow <swinslow@gmail.com>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190528171438.107155473@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:29:52 -07:00

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright Altera Corporation (C) 2013-2014. All rights reserved
*/
#include <linux/device.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.h>
#include <linux/platform_device.h>
#define DRIVER_NAME "altera-mailbox"
#define MAILBOX_CMD_REG 0x00
#define MAILBOX_PTR_REG 0x04
#define MAILBOX_STS_REG 0x08
#define MAILBOX_INTMASK_REG 0x0C
#define INT_PENDING_MSK 0x1
#define INT_SPACE_MSK 0x2
#define STS_PENDING_MSK 0x1
#define STS_FULL_MSK 0x2
#define STS_FULL_OFT 0x1
#define MBOX_PENDING(status) (((status) & STS_PENDING_MSK))
#define MBOX_FULL(status) (((status) & STS_FULL_MSK) >> STS_FULL_OFT)
enum altera_mbox_msg {
MBOX_CMD = 0,
MBOX_PTR,
};
#define MBOX_POLLING_MS 5 /* polling interval 5ms */
struct altera_mbox {
bool is_sender; /* 1-sender, 0-receiver */
bool intr_mode;
int irq;
void __iomem *mbox_base;
struct device *dev;
struct mbox_controller controller;
/* If the controller supports only RX polling mode */
struct timer_list rxpoll_timer;
struct mbox_chan *chan;
};
static struct altera_mbox *mbox_chan_to_altera_mbox(struct mbox_chan *chan)
{
if (!chan || !chan->con_priv)
return NULL;
return (struct altera_mbox *)chan->con_priv;
}
static inline int altera_mbox_full(struct altera_mbox *mbox)
{
u32 status;
status = readl_relaxed(mbox->mbox_base + MAILBOX_STS_REG);
return MBOX_FULL(status);
}
static inline int altera_mbox_pending(struct altera_mbox *mbox)
{
u32 status;
status = readl_relaxed(mbox->mbox_base + MAILBOX_STS_REG);
return MBOX_PENDING(status);
}
static void altera_mbox_rx_intmask(struct altera_mbox *mbox, bool enable)
{
u32 mask;
mask = readl_relaxed(mbox->mbox_base + MAILBOX_INTMASK_REG);
if (enable)
mask |= INT_PENDING_MSK;
else
mask &= ~INT_PENDING_MSK;
writel_relaxed(mask, mbox->mbox_base + MAILBOX_INTMASK_REG);
}
static void altera_mbox_tx_intmask(struct altera_mbox *mbox, bool enable)
{
u32 mask;
mask = readl_relaxed(mbox->mbox_base + MAILBOX_INTMASK_REG);
if (enable)
mask |= INT_SPACE_MSK;
else
mask &= ~INT_SPACE_MSK;
writel_relaxed(mask, mbox->mbox_base + MAILBOX_INTMASK_REG);
}
static bool altera_mbox_is_sender(struct altera_mbox *mbox)
{
u32 reg;
/* Write a magic number to PTR register and read back this register.
* This register is read-write if it is a sender.
*/
#define MBOX_MAGIC 0xA5A5AA55
writel_relaxed(MBOX_MAGIC, mbox->mbox_base + MAILBOX_PTR_REG);
reg = readl_relaxed(mbox->mbox_base + MAILBOX_PTR_REG);
if (reg == MBOX_MAGIC) {
/* Clear to 0 */
writel_relaxed(0, mbox->mbox_base + MAILBOX_PTR_REG);
return true;
}
return false;
}
static void altera_mbox_rx_data(struct mbox_chan *chan)
{
struct altera_mbox *mbox = mbox_chan_to_altera_mbox(chan);
u32 data[2];
if (altera_mbox_pending(mbox)) {
data[MBOX_PTR] =
readl_relaxed(mbox->mbox_base + MAILBOX_PTR_REG);
data[MBOX_CMD] =
readl_relaxed(mbox->mbox_base + MAILBOX_CMD_REG);
mbox_chan_received_data(chan, (void *)data);
}
}
static void altera_mbox_poll_rx(struct timer_list *t)
{
struct altera_mbox *mbox = from_timer(mbox, t, rxpoll_timer);
altera_mbox_rx_data(mbox->chan);
mod_timer(&mbox->rxpoll_timer,
jiffies + msecs_to_jiffies(MBOX_POLLING_MS));
}
static irqreturn_t altera_mbox_tx_interrupt(int irq, void *p)
{
struct mbox_chan *chan = (struct mbox_chan *)p;
struct altera_mbox *mbox = mbox_chan_to_altera_mbox(chan);
altera_mbox_tx_intmask(mbox, false);
mbox_chan_txdone(chan, 0);
return IRQ_HANDLED;
}
static irqreturn_t altera_mbox_rx_interrupt(int irq, void *p)
{
struct mbox_chan *chan = (struct mbox_chan *)p;
altera_mbox_rx_data(chan);
return IRQ_HANDLED;
}
static int altera_mbox_startup_sender(struct mbox_chan *chan)
{
int ret;
struct altera_mbox *mbox = mbox_chan_to_altera_mbox(chan);
if (mbox->intr_mode) {
ret = request_irq(mbox->irq, altera_mbox_tx_interrupt, 0,
DRIVER_NAME, chan);
if (unlikely(ret)) {
dev_err(mbox->dev,
"failed to register mailbox interrupt:%d\n",
ret);
return ret;
}
}
return 0;
}
static int altera_mbox_startup_receiver(struct mbox_chan *chan)
{
int ret;
struct altera_mbox *mbox = mbox_chan_to_altera_mbox(chan);
if (mbox->intr_mode) {
ret = request_irq(mbox->irq, altera_mbox_rx_interrupt, 0,
DRIVER_NAME, chan);
if (unlikely(ret)) {
mbox->intr_mode = false;
goto polling; /* use polling if failed */
}
altera_mbox_rx_intmask(mbox, true);
return 0;
}
polling:
/* Setup polling timer */
mbox->chan = chan;
timer_setup(&mbox->rxpoll_timer, altera_mbox_poll_rx, 0);
mod_timer(&mbox->rxpoll_timer,
jiffies + msecs_to_jiffies(MBOX_POLLING_MS));
return 0;
}
static int altera_mbox_send_data(struct mbox_chan *chan, void *data)
{
struct altera_mbox *mbox = mbox_chan_to_altera_mbox(chan);
u32 *udata = (u32 *)data;
if (!mbox || !data)
return -EINVAL;
if (!mbox->is_sender) {
dev_warn(mbox->dev,
"failed to send. This is receiver mailbox.\n");
return -EINVAL;
}
if (altera_mbox_full(mbox))
return -EBUSY;
/* Enable interrupt before send */
if (mbox->intr_mode)
altera_mbox_tx_intmask(mbox, true);
/* Pointer register must write before command register */
writel_relaxed(udata[MBOX_PTR], mbox->mbox_base + MAILBOX_PTR_REG);
writel_relaxed(udata[MBOX_CMD], mbox->mbox_base + MAILBOX_CMD_REG);
return 0;
}
static bool altera_mbox_last_tx_done(struct mbox_chan *chan)
{
struct altera_mbox *mbox = mbox_chan_to_altera_mbox(chan);
/* Return false if mailbox is full */
return altera_mbox_full(mbox) ? false : true;
}
static bool altera_mbox_peek_data(struct mbox_chan *chan)
{
struct altera_mbox *mbox = mbox_chan_to_altera_mbox(chan);
return altera_mbox_pending(mbox) ? true : false;
}
static int altera_mbox_startup(struct mbox_chan *chan)
{
struct altera_mbox *mbox = mbox_chan_to_altera_mbox(chan);
int ret = 0;
if (!mbox)
return -EINVAL;
if (mbox->is_sender)
ret = altera_mbox_startup_sender(chan);
else
ret = altera_mbox_startup_receiver(chan);
return ret;
}
static void altera_mbox_shutdown(struct mbox_chan *chan)
{
struct altera_mbox *mbox = mbox_chan_to_altera_mbox(chan);
if (mbox->intr_mode) {
/* Unmask all interrupt masks */
writel_relaxed(~0, mbox->mbox_base + MAILBOX_INTMASK_REG);
free_irq(mbox->irq, chan);
} else if (!mbox->is_sender) {
del_timer_sync(&mbox->rxpoll_timer);
}
}
static const struct mbox_chan_ops altera_mbox_ops = {
.send_data = altera_mbox_send_data,
.startup = altera_mbox_startup,
.shutdown = altera_mbox_shutdown,
.last_tx_done = altera_mbox_last_tx_done,
.peek_data = altera_mbox_peek_data,
};
static int altera_mbox_probe(struct platform_device *pdev)
{
struct altera_mbox *mbox;
struct resource *regs;
struct mbox_chan *chans;
int ret;
mbox = devm_kzalloc(&pdev->dev, sizeof(*mbox),
GFP_KERNEL);
if (!mbox)
return -ENOMEM;
/* Allocated one channel */
chans = devm_kzalloc(&pdev->dev, sizeof(*chans), GFP_KERNEL);
if (!chans)
return -ENOMEM;
regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
mbox->mbox_base = devm_ioremap_resource(&pdev->dev, regs);
if (IS_ERR(mbox->mbox_base))
return PTR_ERR(mbox->mbox_base);
/* Check is it a sender or receiver? */
mbox->is_sender = altera_mbox_is_sender(mbox);
mbox->irq = platform_get_irq(pdev, 0);
if (mbox->irq >= 0)
mbox->intr_mode = true;
mbox->dev = &pdev->dev;
/* Hardware supports only one channel. */
chans[0].con_priv = mbox;
mbox->controller.dev = mbox->dev;
mbox->controller.num_chans = 1;
mbox->controller.chans = chans;
mbox->controller.ops = &altera_mbox_ops;
if (mbox->is_sender) {
if (mbox->intr_mode) {
mbox->controller.txdone_irq = true;
} else {
mbox->controller.txdone_poll = true;
mbox->controller.txpoll_period = MBOX_POLLING_MS;
}
}
ret = devm_mbox_controller_register(&pdev->dev, &mbox->controller);
if (ret) {
dev_err(&pdev->dev, "Register mailbox failed\n");
goto err;
}
platform_set_drvdata(pdev, mbox);
err:
return ret;
}
static const struct of_device_id altera_mbox_match[] = {
{ .compatible = "altr,mailbox-1.0" },
{ /* Sentinel */ }
};
MODULE_DEVICE_TABLE(of, altera_mbox_match);
static struct platform_driver altera_mbox_driver = {
.probe = altera_mbox_probe,
.driver = {
.name = DRIVER_NAME,
.of_match_table = altera_mbox_match,
},
};
module_platform_driver(altera_mbox_driver);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Altera mailbox specific functions");
MODULE_AUTHOR("Ley Foon Tan <lftan@altera.com>");
MODULE_ALIAS("platform:altera-mailbox");
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