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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Designware HDMI CEC driver4 *5 * Copyright (C) 2015-2017 Russell King.6 */7#include <linux/interrupt.h>8#include <linux/io.h>9#include <linux/module.h>10#include <linux/platform_device.h>11#include <linux/sched.h>12#include <linux/slab.h>13 14#include <drm/drm_edid.h>15 16#include <media/cec.h>17#include <media/cec-notifier.h>18 19#include "dw-hdmi-cec.h"20 21enum {22 HDMI_IH_CEC_STAT0 = 0x0106,23 HDMI_IH_MUTE_CEC_STAT0 = 0x0186,24 25 HDMI_CEC_CTRL = 0x7d00,26 CEC_CTRL_START = BIT(0),27 CEC_CTRL_FRAME_TYP = 3 << 1,28 CEC_CTRL_RETRY = 0 << 1,29 CEC_CTRL_NORMAL = 1 << 1,30 CEC_CTRL_IMMED = 2 << 1,31 32 HDMI_CEC_STAT = 0x7d01,33 CEC_STAT_DONE = BIT(0),34 CEC_STAT_EOM = BIT(1),35 CEC_STAT_NACK = BIT(2),36 CEC_STAT_ARBLOST = BIT(3),37 CEC_STAT_ERROR_INIT = BIT(4),38 CEC_STAT_ERROR_FOLL = BIT(5),39 CEC_STAT_WAKEUP = BIT(6),40 41 HDMI_CEC_MASK = 0x7d02,42 HDMI_CEC_POLARITY = 0x7d03,43 HDMI_CEC_INT = 0x7d04,44 HDMI_CEC_ADDR_L = 0x7d05,45 HDMI_CEC_ADDR_H = 0x7d06,46 HDMI_CEC_TX_CNT = 0x7d07,47 HDMI_CEC_RX_CNT = 0x7d08,48 HDMI_CEC_TX_DATA0 = 0x7d10,49 HDMI_CEC_RX_DATA0 = 0x7d20,50 HDMI_CEC_LOCK = 0x7d30,51 HDMI_CEC_WKUPCTRL = 0x7d31,52};53 54struct dw_hdmi_cec {55 struct dw_hdmi *hdmi;56 const struct dw_hdmi_cec_ops *ops;57 u32 addresses;58 struct cec_adapter *adap;59 struct cec_msg rx_msg;60 unsigned int tx_status;61 bool tx_done;62 bool rx_done;63 struct cec_notifier *notify;64 int irq;65 66 u8 regs_polarity;67 u8 regs_mask;68 u8 regs_mute_stat0;69};70 71static void dw_hdmi_write(struct dw_hdmi_cec *cec, u8 val, int offset)72{73 cec->ops->write(cec->hdmi, val, offset);74}75 76static u8 dw_hdmi_read(struct dw_hdmi_cec *cec, int offset)77{78 return cec->ops->read(cec->hdmi, offset);79}80 81static int dw_hdmi_cec_log_addr(struct cec_adapter *adap, u8 logical_addr)82{83 struct dw_hdmi_cec *cec = cec_get_drvdata(adap);84 85 if (logical_addr == CEC_LOG_ADDR_INVALID)86 cec->addresses = 0;87 else88 cec->addresses |= BIT(logical_addr) | BIT(15);89 90 dw_hdmi_write(cec, cec->addresses & 255, HDMI_CEC_ADDR_L);91 dw_hdmi_write(cec, cec->addresses >> 8, HDMI_CEC_ADDR_H);92 93 return 0;94}95 96static int dw_hdmi_cec_transmit(struct cec_adapter *adap, u8 attempts,97 u32 signal_free_time, struct cec_msg *msg)98{99 struct dw_hdmi_cec *cec = cec_get_drvdata(adap);100 unsigned int i, ctrl;101 102 switch (signal_free_time) {103 case CEC_SIGNAL_FREE_TIME_RETRY:104 ctrl = CEC_CTRL_RETRY;105 break;106 case CEC_SIGNAL_FREE_TIME_NEW_INITIATOR:107 default:108 ctrl = CEC_CTRL_NORMAL;109 break;110 case CEC_SIGNAL_FREE_TIME_NEXT_XFER:111 ctrl = CEC_CTRL_IMMED;112 break;113 }114 115 for (i = 0; i < msg->len; i++)116 dw_hdmi_write(cec, msg->msg[i], HDMI_CEC_TX_DATA0 + i);117 118 dw_hdmi_write(cec, msg->len, HDMI_CEC_TX_CNT);119 dw_hdmi_write(cec, ctrl | CEC_CTRL_START, HDMI_CEC_CTRL);120 121 return 0;122}123 124static irqreturn_t dw_hdmi_cec_hardirq(int irq, void *data)125{126 struct cec_adapter *adap = data;127 struct dw_hdmi_cec *cec = cec_get_drvdata(adap);128 unsigned int stat = dw_hdmi_read(cec, HDMI_IH_CEC_STAT0);129 irqreturn_t ret = IRQ_HANDLED;130 131 if (stat == 0)132 return IRQ_NONE;133 134 dw_hdmi_write(cec, stat, HDMI_IH_CEC_STAT0);135 136 if (stat & CEC_STAT_ERROR_INIT) {137 cec->tx_status = CEC_TX_STATUS_ERROR;138 cec->tx_done = true;139 ret = IRQ_WAKE_THREAD;140 } else if (stat & CEC_STAT_DONE) {141 cec->tx_status = CEC_TX_STATUS_OK;142 cec->tx_done = true;143 ret = IRQ_WAKE_THREAD;144 } else if (stat & CEC_STAT_NACK) {145 cec->tx_status = CEC_TX_STATUS_NACK;146 cec->tx_done = true;147 ret = IRQ_WAKE_THREAD;148 } else if (stat & CEC_STAT_ARBLOST) {149 cec->tx_status = CEC_TX_STATUS_ARB_LOST;150 cec->tx_done = true;151 ret = IRQ_WAKE_THREAD;152 }153 154 if (stat & CEC_STAT_EOM) {155 unsigned int len, i;156 157 len = dw_hdmi_read(cec, HDMI_CEC_RX_CNT);158 if (len > sizeof(cec->rx_msg.msg))159 len = sizeof(cec->rx_msg.msg);160 161 for (i = 0; i < len; i++)162 cec->rx_msg.msg[i] =163 dw_hdmi_read(cec, HDMI_CEC_RX_DATA0 + i);164 165 dw_hdmi_write(cec, 0, HDMI_CEC_LOCK);166 167 cec->rx_msg.len = len;168 smp_wmb();169 cec->rx_done = true;170 171 ret = IRQ_WAKE_THREAD;172 }173 174 return ret;175}176 177static irqreturn_t dw_hdmi_cec_thread(int irq, void *data)178{179 struct cec_adapter *adap = data;180 struct dw_hdmi_cec *cec = cec_get_drvdata(adap);181 182 if (cec->tx_done) {183 cec->tx_done = false;184 cec_transmit_attempt_done(adap, cec->tx_status);185 }186 if (cec->rx_done) {187 cec->rx_done = false;188 smp_rmb();189 cec_received_msg(adap, &cec->rx_msg);190 }191 return IRQ_HANDLED;192}193 194static int dw_hdmi_cec_enable(struct cec_adapter *adap, bool enable)195{196 struct dw_hdmi_cec *cec = cec_get_drvdata(adap);197 198 if (!enable) {199 dw_hdmi_write(cec, ~0, HDMI_CEC_MASK);200 dw_hdmi_write(cec, ~0, HDMI_IH_MUTE_CEC_STAT0);201 dw_hdmi_write(cec, 0, HDMI_CEC_POLARITY);202 203 cec->ops->disable(cec->hdmi);204 } else {205 unsigned int irqs;206 207 dw_hdmi_write(cec, 0, HDMI_CEC_CTRL);208 dw_hdmi_write(cec, ~0, HDMI_IH_CEC_STAT0);209 dw_hdmi_write(cec, 0, HDMI_CEC_LOCK);210 211 dw_hdmi_cec_log_addr(cec->adap, CEC_LOG_ADDR_INVALID);212 213 cec->ops->enable(cec->hdmi);214 215 irqs = CEC_STAT_ERROR_INIT | CEC_STAT_NACK | CEC_STAT_EOM |216 CEC_STAT_ARBLOST | CEC_STAT_DONE;217 dw_hdmi_write(cec, irqs, HDMI_CEC_POLARITY);218 dw_hdmi_write(cec, ~irqs, HDMI_CEC_MASK);219 dw_hdmi_write(cec, ~irqs, HDMI_IH_MUTE_CEC_STAT0);220 }221 return 0;222}223 224static const struct cec_adap_ops dw_hdmi_cec_ops = {225 .adap_enable = dw_hdmi_cec_enable,226 .adap_log_addr = dw_hdmi_cec_log_addr,227 .adap_transmit = dw_hdmi_cec_transmit,228};229 230static void dw_hdmi_cec_del(void *data)231{232 struct dw_hdmi_cec *cec = data;233 234 cec_delete_adapter(cec->adap);235}236 237static int dw_hdmi_cec_probe(struct platform_device *pdev)238{239 struct dw_hdmi_cec_data *data = dev_get_platdata(&pdev->dev);240 struct dw_hdmi_cec *cec;241 int ret;242 243 if (!data)244 return -ENXIO;245 246 /*247 * Our device is just a convenience - we want to link to the real248 * hardware device here, so that userspace can see the association249 * between the HDMI hardware and its associated CEC chardev.250 */251 cec = devm_kzalloc(&pdev->dev, sizeof(*cec), GFP_KERNEL);252 if (!cec)253 return -ENOMEM;254 255 cec->irq = data->irq;256 cec->ops = data->ops;257 cec->hdmi = data->hdmi;258 259 platform_set_drvdata(pdev, cec);260 261 dw_hdmi_write(cec, 0, HDMI_CEC_TX_CNT);262 dw_hdmi_write(cec, ~0, HDMI_CEC_MASK);263 dw_hdmi_write(cec, ~0, HDMI_IH_MUTE_CEC_STAT0);264 dw_hdmi_write(cec, 0, HDMI_CEC_POLARITY);265 266 cec->adap = cec_allocate_adapter(&dw_hdmi_cec_ops, cec, "dw_hdmi",267 CEC_CAP_DEFAULTS |268 CEC_CAP_CONNECTOR_INFO,269 CEC_MAX_LOG_ADDRS);270 if (IS_ERR(cec->adap))271 return PTR_ERR(cec->adap);272 273 /* override the module pointer */274 cec->adap->owner = THIS_MODULE;275 276 ret = devm_add_action_or_reset(&pdev->dev, dw_hdmi_cec_del, cec);277 if (ret)278 return ret;279 280 ret = devm_request_threaded_irq(&pdev->dev, cec->irq,281 dw_hdmi_cec_hardirq,282 dw_hdmi_cec_thread, IRQF_SHARED,283 "dw-hdmi-cec", cec->adap);284 if (ret < 0)285 return ret;286 287 cec->notify = cec_notifier_cec_adap_register(pdev->dev.parent,288 NULL, cec->adap);289 if (!cec->notify)290 return -ENOMEM;291 292 ret = cec_register_adapter(cec->adap, pdev->dev.parent);293 if (ret < 0) {294 cec_notifier_cec_adap_unregister(cec->notify, cec->adap);295 return ret;296 }297 298 /*299 * CEC documentation says we must not call cec_delete_adapter300 * after a successful call to cec_register_adapter().301 */302 devm_remove_action(&pdev->dev, dw_hdmi_cec_del, cec);303 304 return 0;305}306 307static void dw_hdmi_cec_remove(struct platform_device *pdev)308{309 struct dw_hdmi_cec *cec = platform_get_drvdata(pdev);310 311 cec_notifier_cec_adap_unregister(cec->notify, cec->adap);312 cec_unregister_adapter(cec->adap);313}314 315static int __maybe_unused dw_hdmi_cec_resume(struct device *dev)316{317 struct dw_hdmi_cec *cec = dev_get_drvdata(dev);318 319 /* Restore logical address */320 dw_hdmi_write(cec, cec->addresses & 255, HDMI_CEC_ADDR_L);321 dw_hdmi_write(cec, cec->addresses >> 8, HDMI_CEC_ADDR_H);322 323 /* Restore interrupt status/mask registers */324 dw_hdmi_write(cec, cec->regs_polarity, HDMI_CEC_POLARITY);325 dw_hdmi_write(cec, cec->regs_mask, HDMI_CEC_MASK);326 dw_hdmi_write(cec, cec->regs_mute_stat0, HDMI_IH_MUTE_CEC_STAT0);327 328 return 0;329}330 331static int __maybe_unused dw_hdmi_cec_suspend(struct device *dev)332{333 struct dw_hdmi_cec *cec = dev_get_drvdata(dev);334 335 /* store interrupt status/mask registers */336 cec->regs_polarity = dw_hdmi_read(cec, HDMI_CEC_POLARITY);337 cec->regs_mask = dw_hdmi_read(cec, HDMI_CEC_MASK);338 cec->regs_mute_stat0 = dw_hdmi_read(cec, HDMI_IH_MUTE_CEC_STAT0);339 340 return 0;341}342 343static const struct dev_pm_ops dw_hdmi_cec_pm = {344 SET_SYSTEM_SLEEP_PM_OPS(dw_hdmi_cec_suspend, dw_hdmi_cec_resume)345};346 347static struct platform_driver dw_hdmi_cec_driver = {348 .probe = dw_hdmi_cec_probe,349 .remove_new = dw_hdmi_cec_remove,350 .driver = {351 .name = "dw-hdmi-cec",352 .pm = &dw_hdmi_cec_pm,353 },354};355module_platform_driver(dw_hdmi_cec_driver);356 357MODULE_AUTHOR("Russell King <rmk+kernel@armlinux.org.uk>");358MODULE_DESCRIPTION("Synopsys Designware HDMI CEC driver for i.MX");359MODULE_LICENSE("GPL");360MODULE_ALIAS(PLATFORM_MODULE_PREFIX "dw-hdmi-cec");361