/*
* APM X-Gene SLIMpro MailBox Driver
*
* Copyright (c) 2015, Applied Micro Circuits Corporation
* Author: Feng Kan fkan@apm.com
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that 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/>.
*
*/
#include <linux/acpi.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/mailbox_controller.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/spinlock.h>
#define MBOX_CON_NAME "slimpro-mbox"
#define MBOX_REG_SET_OFFSET 0x1000
#define MBOX_CNT 8
#define MBOX_STATUS_AVAIL_MASK BIT(16)
#define MBOX_STATUS_ACK_MASK BIT(0)
/* Configuration and Status Registers */
#define REG_DB_IN 0x00
#define REG_DB_DIN0 0x04
#define REG_DB_DIN1 0x08
#define REG_DB_OUT 0x10
#define REG_DB_DOUT0 0x14
#define REG_DB_DOUT1 0x18
#define REG_DB_STAT 0x20
#define REG_DB_STATMASK 0x24
/**
* X-Gene SlimPRO mailbox channel information
*
* @dev: Device to which it is attached
* @chan: Pointer to mailbox communication channel
* @reg: Base address to access channel registers
* @irq: Interrupt number of the channel
* @rx_msg: Received message storage
*/
struct slimpro_mbox_chan {
struct device *dev;
struct mbox_chan *chan;
void __iomem *reg;
int irq;
u32 rx_msg[3];
};
/**
* X-Gene SlimPRO Mailbox controller data
*
* X-Gene SlimPRO Mailbox controller has 8 commnunication channels.
* Each channel has a separate IRQ number assgined to it.
*
* @mb_ctrl: Representation of the commnunication channel controller
* @mc: Array of SlimPRO mailbox channels of the controller
* @chans: Array of mailbox communication channels
*
*/
struct slimpro_mbox {
struct mbox_controller mb_ctrl;
struct slimpro_mbox_chan mc[MBOX_CNT];
struct mbox_chan chans[MBOX_CNT];
};
static void mb_chan_send_msg(struct slimpro_mbox_chan *mb_chan, u32 *msg)
{
writel(msg[1], mb_chan->reg + REG_DB_DOUT0);
writel(msg[2], mb_chan->reg + REG_DB_DOUT1);
writel(msg[0], mb_chan->reg + REG_DB_OUT);
}
static void mb_chan_recv_msg(struct slimpro_mbox_chan *mb_chan)
{
mb_chan->rx_msg[1] = readl(mb_chan->reg + REG_DB_DIN0);
mb_chan->rx_msg[2] = readl(mb_chan->reg + REG_DB_DIN1);
mb_chan->rx_msg[0] = readl(mb_chan->reg + REG_DB_IN);
}
static int mb_chan_status_ack(struct slimpro_mbox_chan *mb_chan)
{
u32 val = readl(mb_chan->reg + REG_DB_STAT);
if (val & MBOX_STATUS_ACK_MASK) {
writel(MBOX_STATUS_ACK_MASK, mb_chan->reg + REG_DB_STAT);
return 1;
}
return 0;
}
static int mb_chan_status_avail(struct slimpro_mbox_chan *mb_chan)
{
u32 val = readl(mb_chan->reg + REG_DB_STAT);
if (val & MBOX_STATUS_AVAIL_MASK) {
mb_chan_recv_msg(mb_chan);
writel(MBOX_STATUS_AVAIL_MASK, mb_chan->reg + REG_DB_STAT);
return 1;
}
return 0;
}
static irqreturn_t slimpro_mbox_irq(int irq, void *id)
{
struct slimpro_mbox_chan *mb_chan = id;
if (mb_chan_status_ack(mb_chan))
mbox_chan_txdone(mb_chan->chan, 0);
if (mb_chan_status_avail(mb_chan))
mbox_chan_received_data(mb_chan->chan, mb_chan->rx_msg);
return IRQ_HANDLED;
}
static int slimpro_mbox_send_data(struct mbox_chan *chan, void *msg)
{
struct slimpro_mbox_chan *mb_chan = chan->con_priv;
mb_chan_send_msg(mb_chan, msg);
return 0;
}
static int slimpro_mbox_startup(struct mbox_chan *chan)
{
struct slimpro_mbox_chan *mb_chan = chan->con_priv;
int rc;
u32 val;
rc = devm_request_irq(mb_chan->dev, mb_chan->irq, slimpro_mbox_irq, 0,
MBOX_CON_NAME, mb_chan);
if (unlikely(rc)) {
dev_err(mb_chan->dev, "failed to register mailbox interrupt %d\n",
mb_chan->irq);
return rc;
}
/* Enable HW interrupt */
writel(MBOX_STATUS_ACK_MASK | MBOX_STATUS_AVAIL_MASK,
mb_chan->reg + REG_DB_STAT);
/* Unmask doorbell status interrupt */
val = readl(mb_chan->reg + REG_DB_STATMASK);
val &= ~(MBOX_STATUS_ACK_MASK | MBOX_STATUS_AVAIL_MASK);
writel(val, mb_chan->reg + REG_DB_STATMASK);
return 0;
}
static void slimpro_mbox_shutdown(struct mbox_chan *chan)
{
struct slimpro_mbox_chan *mb_chan = chan->con_priv;
u32 val;
/* Mask doorbell status interrupt */
val = readl(mb_chan->reg + REG_DB_STATMASK);
val |= (MBOX_STATUS_ACK_MASK | MBOX_STATUS_AVAIL_MASK);
writel(val, mb_chan->reg + REG_DB_STATMASK);
devm_free_irq(mb_chan->dev, mb_chan->irq, mb_chan);
}
static struct mbox_chan_ops slimpro_mbox_ops = {
.send_data = slimpro_mbox_send_data,
.startup = slimpro_mbox_startup,
.shutdown = slimpro_mbox_shutdown,
};
static int slimpro_mbox_probe(struct platform_device *pdev)
{
struct slimpro_mbox *ctx;
struct resource *regs;
void __iomem *mb_base;
int rc;
int i;
ctx = devm_kzalloc(&pdev->dev, sizeof(struct slimpro_mbox), GFP_KERNEL);
if (!ctx)
return -ENOMEM;
platform_set_drvdata(pdev, ctx);
regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
mb_base = devm_ioremap(&pdev->dev, regs->start, resource_size(regs));
if (!mb_base)
return -ENOMEM;
/* Setup mailbox links */
for (i = 0; i < MBOX_CNT; i++) {
ctx->mc[i].irq = platform_get_irq(pdev, i);
if (ctx->mc[i].irq < 0) {
if (i == 0) {
dev_err(&pdev->dev, "no available IRQ\n");
return -EINVAL;
}
dev_info(&pdev->dev, "no IRQ for channel %d\n", i);
break;
}
ctx->mc[i].dev = &pdev->dev;
ctx->mc[i].reg = mb_base + i * MBOX_REG_SET_OFFSET;
ctx->mc[i].chan = &ctx->chans[i];
ctx->chans[i].con_priv = &ctx->mc[i];
}
/* Setup mailbox controller */
ctx->mb_ctrl.dev = &pdev->dev;
ctx->mb_ctrl.chans = ctx->chans;
ctx->mb_ctrl.txdone_irq = true;
ctx->mb_ctrl.ops = &slimpro_mbox_ops;
ctx->mb_ctrl.num_chans = i;
rc = mbox_controller_register(&ctx->mb_ctrl);
if (rc) {
dev_err(&pdev->dev,
"APM X-Gene SLIMpro MailBox register failed:%d\n", rc);
return rc;
}
dev_info(&pdev->dev, "APM X-Gene SLIMpro MailBox registered\n");
return 0;
}
static int slimpro_mbox_remove(struct platform_device *pdev)
{
struct slimpro_mbox *smb = platform_get_drvdata(pdev);
mbox_controller_unregister(&smb->mb_ctrl);
return 0;
}
static const struct of_device_id slimpro_of_match[] = {
{.compatible = "apm,xgene-slimpro-mbox" },
{ },
};
MODULE_DEVICE_TABLE(of, slimpro_of_match);
#ifdef CONFIG_ACPI
static const struct acpi_device_id slimpro_acpi_ids[] = {
{"APMC0D01", 0},
{}
};
MODULE_DEVICE_TABLE(acpi, slimpro_acpi_ids);
#endif
static struct platform_driver slimpro_mbox_driver = {
.probe = slimpro_mbox_probe,
.remove = slimpro_mbox_remove,
.driver = {
.name = "xgene-slimpro-mbox",
.of_match_table = of_match_ptr(slimpro_of_match),
.acpi_match_table = ACPI_PTR(slimpro_acpi_ids)
},
};
static int __init slimpro_mbox_init(void)
{
return platform_driver_register(&slimpro_mbox_driver);
}
static void __exit slimpro_mbox_exit(void)
{
platform_driver_unregister(&slimpro_mbox_driver);
}
subsys_initcall(slimpro_mbox_init);
module_exit(slimpro_mbox_exit);
MODULE_DESCRIPTION("APM X-Gene SLIMpro Mailbox Driver");
MODULE_LICENSE("GPL");
