The Chrome OS Embedded Controller can expose a CEC bus, this patch add the driver for such feature of the Embedded Controller.
This driver is part of the cros-ec MFD and will be add as a sub-device when the feature bit is exposed by the EC.
The controller will only handle a single logical address and handles all the messages retries and will only expose Success or Error.
When the logical address is invalid, the controller will act as a CEC sniffer and transfer all messages on the bus.
Signed-off-by: Neil Armstrong narmstrong@baylibre.com --- drivers/media/platform/Kconfig | 11 + drivers/media/platform/Makefile | 2 + drivers/media/platform/cros-ec/Makefile | 1 + drivers/media/platform/cros-ec/cros-ec-cec.c | 331 +++++++++++++++++++++++++++ 4 files changed, 345 insertions(+) create mode 100644 drivers/media/platform/cros-ec/Makefile create mode 100644 drivers/media/platform/cros-ec/cros-ec-cec.c
diff --git a/drivers/media/platform/Kconfig b/drivers/media/platform/Kconfig index c7a1cf8..e55a8ed2 100644 --- a/drivers/media/platform/Kconfig +++ b/drivers/media/platform/Kconfig @@ -546,6 +546,17 @@ menuconfig CEC_PLATFORM_DRIVERS
if CEC_PLATFORM_DRIVERS
+config VIDEO_CROS_EC_CEC + tristate "Chrome OS EC CEC driver" + depends on MFD_CROS_EC || COMPILE_TEST + select CEC_CORE + select CEC_NOTIFIER + ---help--- + If you say yes here you will get support for the + Chrome OS Embedded Controller's CEC. + The CEC bus is present in the HDMI connector and enables communication + between compatible devices. + config VIDEO_MESON_AO_CEC tristate "Amlogic Meson AO CEC driver" depends on ARCH_MESON || COMPILE_TEST diff --git a/drivers/media/platform/Makefile b/drivers/media/platform/Makefile index 932515d..0e0582e 100644 --- a/drivers/media/platform/Makefile +++ b/drivers/media/platform/Makefile @@ -92,3 +92,5 @@ obj-$(CONFIG_VIDEO_QCOM_CAMSS) += qcom/camss-8x16/ obj-$(CONFIG_VIDEO_QCOM_VENUS) += qcom/venus/
obj-y += meson/ + +obj-y += cros-ec/ diff --git a/drivers/media/platform/cros-ec/Makefile b/drivers/media/platform/cros-ec/Makefile new file mode 100644 index 0000000..9ce97f9 --- /dev/null +++ b/drivers/media/platform/cros-ec/Makefile @@ -0,0 +1 @@ +obj-$(CONFIG_VIDEO_CROS_EC_CEC) += cros-ec-cec.o diff --git a/drivers/media/platform/cros-ec/cros-ec-cec.c b/drivers/media/platform/cros-ec/cros-ec-cec.c new file mode 100644 index 0000000..fea90da --- /dev/null +++ b/drivers/media/platform/cros-ec/cros-ec-cec.c @@ -0,0 +1,331 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * CEC driver for Chrome OS Embedded Controller + * + * Copyright (c) 2018 BayLibre, SAS + * Author: Neil Armstrong narmstrong@baylibre.com + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/dmi.h> +#include <linux/cec.h> +#include <linux/slab.h> +#include <linux/interrupt.h> +#include <media/cec.h> +#include <media/cec-notifier.h> +#include <linux/mfd/cros_ec.h> +#include <linux/mfd/cros_ec_commands.h> + +#define DRV_NAME "cros-ec-cec" + +/** + * struct cros_ec_cec - Driver data for EC CEC + * + * @cros_ec: Pointer to EC device + * @notifier: Notifier info for responding to EC events + * @adap: CEC adapter + * @notify: CEC notifier pointer + * @rc_msg: storage for a received message + */ +struct cros_ec_cec { + struct cros_ec_device *cros_ec; + struct notifier_block notifier; + struct cec_adapter *adap; + struct cec_notifier *notify; + struct cec_msg rx_msg; +}; + +static void handle_cec_message(struct cros_ec_cec *cros_ec_cec) +{ + struct cros_ec_device *cros_ec = cros_ec_cec->cros_ec; + uint8_t *cec_message = cros_ec->event_data.data.cec_message; + unsigned int len = cros_ec->event_size; + + cros_ec_cec->rx_msg.len = len; + memcpy(cros_ec_cec->rx_msg.msg, cec_message, len); + + cec_received_msg(cros_ec_cec->adap, &cros_ec_cec->rx_msg); +} + +static void handle_cec_event(struct cros_ec_cec *cros_ec_cec) +{ + struct cros_ec_device *cros_ec = cros_ec_cec->cros_ec; + uint32_t events = cros_ec->event_data.data.cec_events; + + if (events & EC_MKBP_CEC_SEND_OK) + cec_transmit_attempt_done(cros_ec_cec->adap, + CEC_TX_STATUS_OK); + + if (events & EC_MKBP_CEC_SEND_FAILED) + cec_transmit_attempt_done(cros_ec_cec->adap, + CEC_TX_STATUS_ERROR); +} + +static int cros_ec_cec_event(struct notifier_block *nb, + unsigned long queued_during_suspend, void *_notify) +{ + struct cros_ec_cec *cros_ec_cec; + struct cros_ec_device *cros_ec; + + cros_ec_cec = container_of(nb, struct cros_ec_cec, notifier); + cros_ec = cros_ec_cec->cros_ec; + + if (cros_ec->event_data.event_type == EC_MKBP_CEC_EVENT) { + handle_cec_event(cros_ec_cec); + return NOTIFY_OK; + } + + if (cros_ec->event_data.event_type == EC_MKBP_EVENT_CEC_MESSAGE) { + handle_cec_message(cros_ec_cec); + return NOTIFY_OK; + } + + return NOTIFY_DONE; +} + +static int cros_ec_cec_set_log_addr(struct cec_adapter *adap, u8 logical_addr) +{ + struct cros_ec_cec *cros_ec_cec = adap->priv; + struct cros_ec_device *cros_ec = cros_ec_cec->cros_ec; + struct { + struct cros_ec_command msg; + struct ec_params_cec_set data; + } __packed msg; + int ret = 0; + + if (logical_addr == CEC_LOG_ADDR_INVALID) + return 0; + + memset(&msg, 0, sizeof(msg)); + msg.msg.command = EC_CMD_CEC_SET; + msg.msg.outsize = sizeof(msg.data); + msg.data.cmd = CEC_CMD_LOGICAL_ADDRESS; + msg.data.address = logical_addr; + + ret = cros_ec_cmd_xfer_status(cros_ec, &msg.msg); + if (ret < 0) { + dev_err(cros_ec->dev, + "error setting CEC logical address on EC: %d\n", ret); + return ret; + } + + return 0; +} + +static int cros_ec_cec_transmit(struct cec_adapter *adap, u8 attempts, + u32 signal_free_time, struct cec_msg *cec_msg) +{ + struct cros_ec_cec *cros_ec_cec = adap->priv; + struct cros_ec_device *cros_ec = cros_ec_cec->cros_ec; + struct { + struct cros_ec_command msg; + struct ec_params_cec_write data; + } __packed msg; + int ret = 0; + + if (cec_msg->len > MAX_CEC_MSG_LEN) + return -EINVAL; + + memset(&msg, 0, sizeof(msg)); + msg.msg.command = EC_CMD_CEC_WRITE_MSG; + msg.msg.outsize = cec_msg->len; + memcpy(msg.data.msg, cec_msg->msg, cec_msg->len); + + ret = cros_ec_cmd_xfer_status(cros_ec, &msg.msg); + if (ret < 0) { + dev_err(cros_ec->dev, + "error writting CEC msg on EC: %d\n", ret); + return ret; + } + + return 0; +} + +static int cros_ec_cec_adap_enable(struct cec_adapter *adap, bool enable) +{ + struct cros_ec_cec *cros_ec_cec = adap->priv; + struct cros_ec_device *cros_ec = cros_ec_cec->cros_ec; + struct { + struct cros_ec_command msg; + struct ec_params_cec_set data; + } __packed msg; + int ret = 0; + + memset(&msg, 0, sizeof(msg)); + msg.msg.command = EC_CMD_CEC_SET; + msg.msg.outsize = sizeof(msg.data); + msg.data.cmd = CEC_CMD_ENABLE; + msg.data.enable = enable; + + ret = cros_ec_cmd_xfer_status(cros_ec, &msg.msg); + if (ret < 0) { + dev_err(cros_ec->dev, + "error %sabling CEC on EC: %d\n", + (enable ? "en" : "dis"), ret); + return ret; + } + + return 0; +} + +static const struct cec_adap_ops cros_ec_cec_ops = { + .adap_enable = cros_ec_cec_adap_enable, + .adap_log_addr = cros_ec_cec_set_log_addr, + .adap_transmit = cros_ec_cec_transmit, +}; + +#ifdef CONFIG_PM_SLEEP +static int cros_ec_cec_suspend(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct cros_ec_cec *cros_ec_cec = dev_get_drvdata(&pdev->dev); + + if (device_may_wakeup(dev)) + enable_irq_wake(cros_ec_cec->cros_ec->irq); + + return 0; +} + +static int cros_ec_cec_resume(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct cros_ec_cec *cros_ec_cec = dev_get_drvdata(&pdev->dev); + + if (device_may_wakeup(dev)) + disable_irq_wake(cros_ec_cec->cros_ec->irq); + + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(cros_ec_cec_pm_ops, + cros_ec_cec_suspend, cros_ec_cec_resume); + + +struct cec_dmi_match { + char *sys_vendor; + char *product_name; + char *devname; + char *conn; +}; + +static const struct cec_dmi_match cec_dmi_match_table[] = { + /* Google Fizz */ + { "Google", "Fizz", "0000:00:02.0", "HDMI-A-1" }, +}; + +static int cros_ec_cec_get_notifier(struct cec_notifier **notify) +{ + int i; + + for (i = 0 ; i < ARRAY_SIZE(cec_dmi_match_table) ; ++i) { + const struct cec_dmi_match *m = &cec_dmi_match_table[i]; + + if (dmi_match(DMI_SYS_VENDOR, m->sys_vendor) && + dmi_match(DMI_PRODUCT_NAME, m->product_name)) { + *notify = cec_notifier_get_byname(m->devname, m->conn); + return 0; + } + } + + return -EINVAL; +} + +static int cros_ec_cec_probe(struct platform_device *pdev) +{ + struct cros_ec_dev *ec_dev = dev_get_drvdata(pdev->dev.parent); + struct cros_ec_device *cros_ec = ec_dev->ec_dev; + struct cros_ec_cec *cros_ec_cec; + unsigned int cec_caps = CEC_CAP_DEFAULTS; + int ret; + + cros_ec_cec = devm_kzalloc(&pdev->dev, sizeof(*cros_ec_cec), + GFP_KERNEL); + if (!cros_ec_cec) + return -ENOMEM; + + platform_set_drvdata(pdev, cros_ec_cec); + cros_ec_cec->cros_ec = cros_ec; + + ret = cros_ec_cec_get_notifier(&cros_ec_cec->notify); + if (ret) { + dev_warn(&pdev->dev, "no CEC notifier available\n"); + cec_caps |= CEC_CAP_PHYS_ADDR; + } else if (!cros_ec_cec->notify) { + return -EPROBE_DEFER; + } + + ret = device_init_wakeup(&pdev->dev, 1); + if (ret) { + dev_err(&pdev->dev, "failed to initialize wakeup\n"); + return ret; + } + + cros_ec_cec->adap = cec_allocate_adapter(&cros_ec_cec_ops, cros_ec_cec, + DRV_NAME, cec_caps, 1); + if (IS_ERR(cros_ec_cec->adap)) + return PTR_ERR(cros_ec_cec->adap); + + cros_ec_cec->adap->owner = THIS_MODULE; + + /* Get CEC events from the EC. */ + cros_ec_cec->notifier.notifier_call = cros_ec_cec_event; + ret = blocking_notifier_chain_register(&cros_ec->event_notifier, + &cros_ec_cec->notifier); + if (ret) { + dev_err(&pdev->dev, "failed to register notifier\n"); + cec_delete_adapter(cros_ec_cec->adap); + return ret; + } + + ret = cec_register_adapter(cros_ec_cec->adap, &pdev->dev); + if (ret < 0) { + cec_delete_adapter(cros_ec_cec->adap); + return ret; + } + + cec_register_cec_notifier(cros_ec_cec->adap, cros_ec_cec->notify); + + return 0; +} + +static int cros_ec_cec_remove(struct platform_device *pdev) +{ + struct cros_ec_cec *cros_ec_cec = platform_get_drvdata(pdev); + struct device *dev = &pdev->dev; + int ret; + + ret = blocking_notifier_chain_unregister( + &cros_ec_cec->cros_ec->event_notifier, + &cros_ec_cec->notifier); + + if (ret) { + dev_err(dev, "failed to unregister notifier\n"); + return ret; + } + + cec_unregister_adapter(cros_ec_cec->adap); + + if (cros_ec_cec->notify) + cec_notifier_put(cros_ec_cec->notify); + + return 0; +} + +static struct platform_driver cros_ec_cec_driver = { + .probe = cros_ec_cec_probe, + .remove = cros_ec_cec_remove, + .driver = { + .name = DRV_NAME, + .pm = &cros_ec_cec_pm_ops, + }, +}; + +module_platform_driver(cros_ec_cec_driver); + +MODULE_DESCRIPTION("CEC driver for Chrome OS ECs"); +MODULE_AUTHOR("Neil Armstrong narmstrong@baylibre.com"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:" DRV_NAME);