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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright 2017 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
*/
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/gpio/consumer.h>
#include <media/cec-pin.h>
struct cec_gpio {
struct cec_adapter *adap;
struct device *dev;
struct gpio_desc *cec_gpio;
int cec_irq;
bool cec_is_low;
bool cec_have_irq;
struct gpio_desc *hpd_gpio;
int hpd_irq;
bool hpd_is_high;
ktime_t hpd_ts;
};
static bool cec_gpio_read(struct cec_adapter *adap)
{
struct cec_gpio *cec = cec_get_drvdata(adap);
if (cec->cec_is_low)
return false;
return gpiod_get_value(cec->cec_gpio);
}
static void cec_gpio_high(struct cec_adapter *adap)
{
struct cec_gpio *cec = cec_get_drvdata(adap);
if (!cec->cec_is_low)
return;
cec->cec_is_low = false;
gpiod_set_value(cec->cec_gpio, 1);
}
static void cec_gpio_low(struct cec_adapter *adap)
{
struct cec_gpio *cec = cec_get_drvdata(adap);
if (cec->cec_is_low)
return;
if (WARN_ON_ONCE(cec->cec_have_irq))
free_irq(cec->cec_irq, cec);
cec->cec_have_irq = false;
cec->cec_is_low = true;
gpiod_set_value(cec->cec_gpio, 0);
}
static irqreturn_t cec_hpd_gpio_irq_handler_thread(int irq, void *priv)
{
struct cec_gpio *cec = priv;
cec_queue_pin_hpd_event(cec->adap, cec->hpd_is_high, cec->hpd_ts);
return IRQ_HANDLED;
}
static irqreturn_t cec_hpd_gpio_irq_handler(int irq, void *priv)
{
struct cec_gpio *cec = priv;
bool is_high = gpiod_get_value(cec->hpd_gpio);
if (is_high == cec->hpd_is_high)
return IRQ_HANDLED;
cec->hpd_ts = ktime_get();
cec->hpd_is_high = is_high;
return IRQ_WAKE_THREAD;
}
static irqreturn_t cec_gpio_irq_handler(int irq, void *priv)
{
struct cec_gpio *cec = priv;
cec_pin_changed(cec->adap, gpiod_get_value(cec->cec_gpio));
return IRQ_HANDLED;
}
static bool cec_gpio_enable_irq(struct cec_adapter *adap)
{
struct cec_gpio *cec = cec_get_drvdata(adap);
if (cec->cec_have_irq)
return true;
if (request_irq(cec->cec_irq, cec_gpio_irq_handler,
IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
adap->name, cec))
return false;
cec->cec_have_irq = true;
return true;
}
static void cec_gpio_disable_irq(struct cec_adapter *adap)
{
struct cec_gpio *cec = cec_get_drvdata(adap);
if (cec->cec_have_irq)
free_irq(cec->cec_irq, cec);
cec->cec_have_irq = false;
}
static void cec_gpio_status(struct cec_adapter *adap, struct seq_file *file)
{
struct cec_gpio *cec = cec_get_drvdata(adap);
seq_printf(file, "mode: %s\n", cec->cec_is_low ? "low-drive" : "read");
if (cec->cec_have_irq)
seq_printf(file, "using irq: %d\n", cec->cec_irq);
if (cec->hpd_gpio)
seq_printf(file, "hpd: %s\n",
cec->hpd_is_high ? "high" : "low");
}
static int cec_gpio_read_hpd(struct cec_adapter *adap)
{
struct cec_gpio *cec = cec_get_drvdata(adap);
if (!cec->hpd_gpio)
return -ENOTTY;
return gpiod_get_value(cec->hpd_gpio);
}
static void cec_gpio_free(struct cec_adapter *adap)
{
cec_gpio_disable_irq(adap);
}
static const struct cec_pin_ops cec_gpio_pin_ops = {
.read = cec_gpio_read,
.low = cec_gpio_low,
.high = cec_gpio_high,
.enable_irq = cec_gpio_enable_irq,
.disable_irq = cec_gpio_disable_irq,
.status = cec_gpio_status,
.free = cec_gpio_free,
.read_hpd = cec_gpio_read_hpd,
};
static int cec_gpio_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct cec_gpio *cec;
int ret;
cec = devm_kzalloc(dev, sizeof(*cec), GFP_KERNEL);
if (!cec)
return -ENOMEM;
cec->dev = dev;
cec->cec_gpio = devm_gpiod_get(dev, "cec", GPIOD_OUT_HIGH_OPEN_DRAIN);
if (IS_ERR(cec->cec_gpio))
return PTR_ERR(cec->cec_gpio);
cec->cec_irq = gpiod_to_irq(cec->cec_gpio);
cec->hpd_gpio = devm_gpiod_get_optional(dev, "hpd", GPIOD_IN);
if (IS_ERR(cec->hpd_gpio))
return PTR_ERR(cec->hpd_gpio);
cec->adap = cec_pin_allocate_adapter(&cec_gpio_pin_ops,
cec, pdev->name, CEC_CAP_DEFAULTS | CEC_CAP_PHYS_ADDR |
CEC_CAP_MONITOR_ALL | CEC_CAP_MONITOR_PIN);
if (IS_ERR(cec->adap))
return PTR_ERR(cec->adap);
if (cec->hpd_gpio) {
cec->hpd_irq = gpiod_to_irq(cec->hpd_gpio);
ret = devm_request_threaded_irq(dev, cec->hpd_irq,
cec_hpd_gpio_irq_handler,
cec_hpd_gpio_irq_handler_thread,
IRQF_ONESHOT |
IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
"hpd-gpio", cec);
if (ret)
return ret;
}
ret = cec_register_adapter(cec->adap, &pdev->dev);
if (ret) {
cec_delete_adapter(cec->adap);
return ret;
}
platform_set_drvdata(pdev, cec);
return 0;
}
static int cec_gpio_remove(struct platform_device *pdev)
{
struct cec_gpio *cec = platform_get_drvdata(pdev);
cec_unregister_adapter(cec->adap);
return 0;
}
static const struct of_device_id cec_gpio_match[] = {
{
.compatible = "cec-gpio",
},
{},
};
MODULE_DEVICE_TABLE(of, cec_gpio_match);
static struct platform_driver cec_gpio_pdrv = {
.probe = cec_gpio_probe,
.remove = cec_gpio_remove,
.driver = {
.name = "cec-gpio",
.of_match_table = cec_gpio_match,
},
};
module_platform_driver(cec_gpio_pdrv);
MODULE_AUTHOR("Hans Verkuil <hans.verkuil@cisco.com>");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("CEC GPIO driver");
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