| // 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; |
| }; |
| |
| 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; |
| } |
| |
| 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_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(&pdev->dev, dw_hdmi_cec_del, cec); |
| if (ret) { |
| cec_delete_adapter(cec->adap); |
| 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 int 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); |
| |
| return 0; |
| } |
| |
| static struct platform_driver dw_hdmi_cec_driver = { |
| .probe = dw_hdmi_cec_probe, |
| .remove = dw_hdmi_cec_remove, |
| .driver = { |
| .name = "dw-hdmi-cec", |
| }, |
| }; |
| module_platform_driver(dw_hdmi_cec_driver); |
| |
| MODULE_AUTHOR("Russell King <rmk+kernel@armlinux.org.uk>"); |
| MODULE_DESCRIPTION("Synopsys Designware HDMI CEC driver for i.MX"); |
| MODULE_LICENSE("GPL"); |
| MODULE_ALIAS(PLATFORM_MODULE_PREFIX "dw-hdmi-cec"); |