// SPDX-License-Identifier: GPL-2.0-only
/*
* Designware HDMI CEC driver
*
* Copyright (C) 2015-2017 Russell King.
*/
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <drm/drm_edid.h>
#include <media/cec.h>
#include <media/cec-notifier.h>
#include "dw-hdmi-cec.h"
enum {
HDMI_IH_CEC_STAT0 = 0x0106,
HDMI_IH_MUTE_CEC_STAT0 = 0x0186,
HDMI_CEC_CTRL = 0x7d00,
CEC_CTRL_START = BIT(0),
CEC_CTRL_FRAME_TYP = 3 << 1,
CEC_CTRL_RETRY = 0 << 1,
CEC_CTRL_NORMAL = 1 << 1,
CEC_CTRL_IMMED = 2 << 1,
HDMI_CEC_STAT = 0x7d01,
CEC_STAT_DONE = BIT(0),
CEC_STAT_EOM = BIT(1),
CEC_STAT_NACK = BIT(2),
CEC_STAT_ARBLOST = BIT(3),
CEC_STAT_ERROR_INIT = BIT(4),
CEC_STAT_ERROR_FOLL = BIT(5),
CEC_STAT_WAKEUP = BIT(6),
HDMI_CEC_MASK = 0x7d02,
HDMI_CEC_POLARITY = 0x7d03,
HDMI_CEC_INT = 0x7d04,
HDMI_CEC_ADDR_L = 0x7d05,
HDMI_CEC_ADDR_H = 0x7d06,
HDMI_CEC_TX_CNT = 0x7d07,
HDMI_CEC_RX_CNT = 0x7d08,
HDMI_CEC_TX_DATA0 = 0x7d10,
HDMI_CEC_RX_DATA0 = 0x7d20,
HDMI_CEC_LOCK = 0x7d30,
HDMI_CEC_WKUPCTRL = 0x7d31,
};
struct dw_hdmi_cec {
struct dw_hdmi *hdmi;
const struct dw_hdmi_cec_ops *ops;
u32 addresses;
struct cec_adapter *adap;
struct cec_msg rx_msg;
unsigned int tx_status;
bool tx_done;
bool rx_done;
struct cec_notifier *notify;
int irq;
u8 regs_polarity;
u8 regs_mask;
u8 regs_mute_stat0;
};
static void dw_hdmi_write(struct dw_hdmi_cec *cec, u8 val, int offset)
{
cec->ops->write(cec->hdmi, val, offset);
}
static u8 dw_hdmi_read(struct dw_hdmi_cec *cec, int offset)
{
return cec->ops->read(cec->hdmi, offset);
}
static int dw_hdmi_cec_log_addr(struct cec_adapter *adap, u8 logical_addr)
{
struct dw_hdmi_cec *cec = cec_get_drvdata(adap);
if (logical_addr == CEC_LOG_ADDR_INVALID)
cec->addresses = 0;
else
cec->addresses |= BIT(logical_addr) | BIT(15);
dw_hdmi_write(cec, cec->addresses & 255, HDMI_CEC_ADDR_L);
dw_hdmi_write(cec, cec->addresses >> 8, HDMI_CEC_ADDR_H);
return 0;
}
static int dw_hdmi_cec_transmit(struct cec_adapter *adap, u8 attempts,
u32 signal_free_time, struct cec_msg *msg)
{
struct dw_hdmi_cec *cec = cec_get_drvdata(adap);
unsigned int i, ctrl;
switch (signal_free_time) {
case CEC_SIGNAL_FREE_TIME_RETRY:
ctrl = CEC_CTRL_RETRY;
break;
case CEC_SIGNAL_FREE_TIME_NEW_INITIATOR:
default:
ctrl = CEC_CTRL_NORMAL;
break;
case CEC_SIGNAL_FREE_TIME_NEXT_XFER:
ctrl = CEC_CTRL_IMMED;
break;
}
for (i = 0; i < msg->len; i++)
dw_hdmi_write(cec, msg->msg[i], HDMI_CEC_TX_DATA0 + i);
dw_hdmi_write(cec, msg->len, HDMI_CEC_TX_CNT);
dw_hdmi_write(cec, ctrl | CEC_CTRL_START, HDMI_CEC_CTRL);
return 0;
}
static irqreturn_t dw_hdmi_cec_hardirq(int irq, void *data)
{
struct cec_adapter *adap = data;
struct dw_hdmi_cec *cec = cec_get_drvdata(adap);
unsigned int stat = dw_hdmi_read(cec, HDMI_IH_CEC_STAT0);
irqreturn_t ret = IRQ_HANDLED;
if (stat == 0)
return IRQ_NONE;
dw_hdmi_write(cec, stat, HDMI_IH_CEC_STAT0);
if (stat & CEC_STAT_ERROR_INIT) {
cec->tx_status = CEC_TX_STATUS_ERROR;
cec->tx_done = true;
ret = IRQ_WAKE_THREAD;
} else if (stat & CEC_STAT_DONE) {
cec->tx_status = CEC_TX_STATUS_OK;
cec->tx_done = true;
ret = IRQ_WAKE_THREAD;
} else if (stat & CEC_STAT_NACK) {
cec->tx_status = CEC_TX_STATUS_NACK;
cec->tx_done = true;
ret = IRQ_WAKE_THREAD;
} else if (stat & CEC_STAT_ARBLOST) {
cec->tx_status = CEC_TX_STATUS_ARB_LOST;
cec->tx_done = true;
ret = IRQ_WAKE_THREAD;
}
if (stat & CEC_STAT_EOM) {
unsigned int len, i;
len = dw_hdmi_read(cec, HDMI_CEC_RX_CNT);
if (len > sizeof(cec->rx_msg.msg))
len = sizeof(cec->rx_msg.msg);
for (i = 0; i < len; i++)
cec->rx_msg.msg[i] =
dw_hdmi_read(cec, HDMI_CEC_RX_DATA0 + i);
dw_hdmi_write(cec, 0, HDMI_CEC_LOCK);
cec->rx_msg.len = len;
smp_wmb();
cec->rx_done = true;
ret = IRQ_WAKE_THREAD;
}
return ret;
}
static irqreturn_t dw_hdmi_cec_thread(int irq, void *data)
{
struct cec_adapter *adap = data;
struct dw_hdmi_cec *cec = cec_get_drvdata(adap);
if (cec->tx_done) {
cec->tx_done = false;
cec_transmit_attempt_done(adap, cec->tx_status);
}
if (cec->rx_done) {
cec->rx_done = false;
smp_rmb();
cec_received_msg(adap, &cec->rx_msg);
}
return IRQ_HANDLED;
}
static int dw_hdmi_cec_enable(struct cec_adapter *adap, bool enable)
{
struct dw_hdmi_cec *cec = cec_get_drvdata(adap);
if (!enable) {
dw_hdmi_write(cec, ~0, HDMI_CEC_MASK);
dw_hdmi_write(cec, ~0, HDMI_IH_MUTE_CEC_STAT0);
dw_hdmi_write(cec, 0, HDMI_CEC_POLARITY);
cec->ops->disable(cec->hdmi);
} else {
unsigned int irqs;
dw_hdmi_write(cec, 0, HDMI_CEC_CTRL);
dw_hdmi_write(cec, ~0, HDMI_IH_CEC_STAT0);
dw_hdmi_write(cec, 0, HDMI_CEC_LOCK);
dw_hdmi_cec_log_addr(cec->adap, CEC_LOG_ADDR_INVALID);
cec->ops->enable(cec->hdmi);
irqs = CEC_STAT_ERROR_INIT | CEC_STAT_NACK | CEC_STAT_EOM |
CEC_STAT_ARBLOST | CEC_STAT_DONE;
dw_hdmi_write(cec, irqs, HDMI_CEC_POLARITY);
dw_hdmi_write(cec, ~irqs, HDMI_CEC_MASK);
dw_hdmi_write(cec, ~irqs, HDMI_IH_MUTE_CEC_STAT0);
}
return 0;
}
static const struct cec_adap_ops dw_hdmi_cec_ops = {
.adap_enable = dw_hdmi_cec_enable,
.adap_log_addr = dw_hdmi_cec_log_addr,
.adap_transmit = dw_hdmi_cec_transmit,
};
static void dw_hdmi_cec_del(void *data)
{
struct dw_hdmi_cec *cec = data;
cec_delete_adapter(cec->adap);
}
static int dw_hdmi_cec_probe(struct platform_device *pdev)
{
struct dw_hdmi_cec_data *data = dev_get_platdata(&pdev->dev);
struct dw_hdmi_cec *cec;
int ret;
if (!data)
return -ENXIO;
/*
* Our device is just a convenience - we want to link to the real
* hardware device here, so that userspace can see the association
* between the HDMI hardware and its associated CEC chardev.
*/
cec = devm_kzalloc(&pdev->dev, sizeof(*cec), GFP_KERNEL);
if (!cec)
return -ENOMEM;
cec->irq = data->irq;
cec->ops = data->ops;
cec->hdmi = data->hdmi;
platform_set_drvdata(pdev, cec);
dw_hdmi_write(cec, 0, HDMI_CEC_TX_CNT);
dw_hdmi_write(cec, ~0, HDMI_CEC_MASK);
dw_hdmi_write(cec, ~0, HDMI_IH_MUTE_CEC_STAT0);
dw_hdmi_write(cec, 0, HDMI_CEC_POLARITY);
cec->adap = cec_allocate_adapter(&dw_hdmi_cec_ops, cec, "dw_hdmi",
CEC_CAP_DEFAULTS |
CEC_CAP_CONNECTOR_INFO,
CEC_MAX_LOG_ADDRS);
if (IS_ERR(cec->adap))
return PTR_ERR(cec->adap);
/* override the module pointer */
cec->adap->owner = THIS_MODULE;
ret = devm_add_action_or_reset(&pdev->dev, dw_hdmi_cec_del, cec);
if (ret)
return ret;
ret = devm_request_threaded_irq(&pdev->dev, cec->irq,
dw_hdmi_cec_hardirq,
dw_hdmi_cec_thread, IRQF_SHARED,
"dw-hdmi-cec", cec->adap);
if (ret < 0)
return ret;
cec->notify = cec_notifier_cec_adap_register(pdev->dev.parent,
NULL, cec->adap);
if (!cec->notify)
return -ENOMEM;
ret = cec_register_adapter(cec->adap, pdev->dev.parent);
if (ret < 0) {
cec_notifier_cec_adap_unregister(cec->notify, cec->adap);
return ret;
}
/*
* CEC documentation says we must not call cec_delete_adapter
* after a successful call to cec_register_adapter().
*/
devm_remove_action(&pdev->dev, dw_hdmi_cec_del, cec);
return 0;
}
static void dw_hdmi_cec_remove(struct platform_device *pdev)
{
struct dw_hdmi_cec *cec = platform_get_drvdata(pdev);
cec_notifier_cec_adap_unregister(cec->notify, cec->adap);
cec_unregister_adapter(cec->adap);
}
static int __maybe_unused dw_hdmi_cec_resume(struct device *dev)
{
struct dw_hdmi_cec *cec = dev_get_drvdata(dev);
/* Restore logical address */
dw_hdmi_write(cec, cec->addresses & 255, HDMI_CEC_ADDR_L);
dw_hdmi_write(cec, cec->addresses >> 8, HDMI_CEC_ADDR_H);
/* Restore interrupt status/mask registers */
dw_hdmi_write(cec, cec->regs_polarity, HDMI_CEC_POLARITY);
dw_hdmi_write(cec, cec->regs_mask, HDMI_CEC_MASK);
dw_hdmi_write(cec, cec->regs_mute_stat0, HDMI_IH_MUTE_CEC_STAT0);
return 0;
}
static int __maybe_unused dw_hdmi_cec_suspend(struct device *dev)
{
struct dw_hdmi_cec *cec = dev_get_drvdata(dev);
/* store interrupt status/mask registers */
cec->regs_polarity = dw_hdmi_read(cec, HDMI_CEC_POLARITY);
cec->regs_mask = dw_hdmi_read(cec, HDMI_CEC_MASK);
cec->regs_mute_stat0 = dw_hdmi_read(cec, HDMI_IH_MUTE_CEC_STAT0);
return 0;
}
static const struct dev_pm_ops dw_hdmi_cec_pm = {
SET_SYSTEM_SLEEP_PM_OPS(dw_hdmi_cec_suspend, dw_hdmi_cec_resume)
};
static struct platform_driver dw_hdmi_cec_driver = {
.probe = dw_hdmi_cec_probe,
.remove_new = dw_hdmi_cec_remove,
.driver = {
.name = "dw-hdmi-cec",
.pm = &dw_hdmi_cec_pm,
},
};
module_platform_driver(dw_hdmi_cec_driver);
MODULE_AUTHOR("Russell King <[email protected]>");
MODULE_DESCRIPTION("Synopsys Designware HDMI CEC driver for i.MX");
MODULE_LICENSE("GPL");
MODULE_ALIAS(PLATFORM_MODULE_PREFIX "dw-hdmi-cec");
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