drivers/gpu/drm/bridge/adv7511/adv7511_cec.c - linux/torvalds/linux - Git at Google

 /*
  * adv7511_cec.c - Analog Devices ADV7511/33 cec driver
  *
  * Copyright 2017 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
  *
  * This program is free software; you may redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; version 2 of the License.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  *
  */

 #include <linux/device.h>
 #include <linux/module.h>
 #include <linux/of_device.h>
 #include <linux/slab.h>
 #include <linux/clk.h>

 #include <media/cec.h>

 #include "adv7511.h"

 #define ADV7511_INT1_CEC_MASK \
 	(ADV7511_INT1_CEC_TX_READY | ADV7511_INT1_CEC_TX_ARBIT_LOST | \
 	 ADV7511_INT1_CEC_TX_RETRY_TIMEOUT | ADV7511_INT1_CEC_RX_READY1)

 static void adv_cec_tx_raw_status(struct adv7511 *adv7511, u8 tx_raw_status)
 {
 	unsigned int offset = adv7511->type == ADV7533 ?
 					ADV7533_REG_CEC_OFFSET : 0;
 	unsigned int val;

 	if (regmap_read(adv7511->regmap_cec,
 			ADV7511_REG_CEC_TX_ENABLE + offset, &val))
 		return;

 	if ((val & 0x01) == 0)
 		return;

 	if (tx_raw_status & ADV7511_INT1_CEC_TX_ARBIT_LOST) {
 		cec_transmit_attempt_done(adv7511->cec_adap,
 					  CEC_TX_STATUS_ARB_LOST);
 		return;
 	}
 	if (tx_raw_status & ADV7511_INT1_CEC_TX_RETRY_TIMEOUT) {
 		u8 status;
 		u8 err_cnt = 0;
 		u8 nack_cnt = 0;
 		u8 low_drive_cnt = 0;
 		unsigned int cnt;

 		/*
 		 * We set this status bit since this hardware performs
 		 * retransmissions.
 		 */
 		status = CEC_TX_STATUS_MAX_RETRIES;
 		if (regmap_read(adv7511->regmap_cec,
 			    ADV7511_REG_CEC_TX_LOW_DRV_CNT + offset, &cnt)) {
 			err_cnt = 1;
 			status |= CEC_TX_STATUS_ERROR;
 		} else {
 			nack_cnt = cnt & 0xf;
 			if (nack_cnt)
 				status |= CEC_TX_STATUS_NACK;
 			low_drive_cnt = cnt >> 4;
 			if (low_drive_cnt)
 				status |= CEC_TX_STATUS_LOW_DRIVE;
 		}
 		cec_transmit_done(adv7511->cec_adap, status,
 				  0, nack_cnt, low_drive_cnt, err_cnt);
 		return;
 	}
 	if (tx_raw_status & ADV7511_INT1_CEC_TX_READY) {
 		cec_transmit_attempt_done(adv7511->cec_adap, CEC_TX_STATUS_OK);
 		return;
 	}
 }

 void adv7511_cec_irq_process(struct adv7511 *adv7511, unsigned int irq1)
 {
 	unsigned int offset = adv7511->type == ADV7533 ?
 					ADV7533_REG_CEC_OFFSET : 0;
 	const u32 irq_tx_mask = ADV7511_INT1_CEC_TX_READY |
 				ADV7511_INT1_CEC_TX_ARBIT_LOST |
 				ADV7511_INT1_CEC_TX_RETRY_TIMEOUT;
 	struct cec_msg msg = {};
 	unsigned int len;
 	unsigned int val;
 	u8 i;

 	if (irq1 & irq_tx_mask)
 		adv_cec_tx_raw_status(adv7511, irq1);

 	if (!(irq1 & ADV7511_INT1_CEC_RX_READY1))
 		return;

 	if (regmap_read(adv7511->regmap_cec,
 			ADV7511_REG_CEC_RX_FRAME_LEN + offset, &len))
 		return;

 	msg.len = len & 0x1f;

 	if (msg.len > 16)
 		msg.len = 16;

 	if (!msg.len)
 		return;

 	for (i = 0; i < msg.len; i++) {
 		regmap_read(adv7511->regmap_cec,
 			    i + ADV7511_REG_CEC_RX_FRAME_HDR + offset, &val);
 		msg.msg[i] = val;
 	}

 	/* toggle to re-enable rx 1 */
 	regmap_write(adv7511->regmap_cec,
 		     ADV7511_REG_CEC_RX_BUFFERS + offset, 1);
 	regmap_write(adv7511->regmap_cec,
 		     ADV7511_REG_CEC_RX_BUFFERS + offset, 0);
 	cec_received_msg(adv7511->cec_adap, &msg);
 }

 static int adv7511_cec_adap_enable(struct cec_adapter *adap, bool enable)
 {
 	struct adv7511 *adv7511 = cec_get_drvdata(adap);
 	unsigned int offset = adv7511->type == ADV7533 ?
 					ADV7533_REG_CEC_OFFSET : 0;

 	if (adv7511->i2c_cec == NULL)
 		return -EIO;

 	if (!adv7511->cec_enabled_adap && enable) {
 		/* power up cec section */
 		regmap_update_bits(adv7511->regmap_cec,
 				   ADV7511_REG_CEC_CLK_DIV + offset,
 				   0x03, 0x01);
 		/* legacy mode and clear all rx buffers */
 		regmap_write(adv7511->regmap_cec,
 			     ADV7511_REG_CEC_RX_BUFFERS + offset, 0x07);
 		regmap_write(adv7511->regmap_cec,
 			     ADV7511_REG_CEC_RX_BUFFERS + offset, 0);
 		/* initially disable tx */
 		regmap_update_bits(adv7511->regmap_cec,
 				   ADV7511_REG_CEC_TX_ENABLE + offset, 1, 0);
 		/* enabled irqs: */
 		/* tx: ready */
 		/* tx: arbitration lost */
 		/* tx: retry timeout */
 		/* rx: ready 1 */
 		regmap_update_bits(adv7511->regmap,
 				   ADV7511_REG_INT_ENABLE(1), 0x3f,
 				   ADV7511_INT1_CEC_MASK);
 	} else if (adv7511->cec_enabled_adap && !enable) {
 		regmap_update_bits(adv7511->regmap,
 				   ADV7511_REG_INT_ENABLE(1), 0x3f, 0);
 		/* disable address mask 1-3 */
 		regmap_update_bits(adv7511->regmap_cec,
 				   ADV7511_REG_CEC_LOG_ADDR_MASK + offset,
 				   0x70, 0x00);
 		/* power down cec section */
 		regmap_update_bits(adv7511->regmap_cec,
 				   ADV7511_REG_CEC_CLK_DIV + offset,
 				   0x03, 0x00);
 		adv7511->cec_valid_addrs = 0;
 	}
 	adv7511->cec_enabled_adap = enable;
 	return 0;
 }

 static int adv7511_cec_adap_log_addr(struct cec_adapter *adap, u8 addr)
 {
 	struct adv7511 *adv7511 = cec_get_drvdata(adap);
 	unsigned int offset = adv7511->type == ADV7533 ?
 					ADV7533_REG_CEC_OFFSET : 0;
 	unsigned int i, free_idx = ADV7511_MAX_ADDRS;

 	if (!adv7511->cec_enabled_adap)
 		return addr == CEC_LOG_ADDR_INVALID ? 0 : -EIO;

 	if (addr == CEC_LOG_ADDR_INVALID) {
 		regmap_update_bits(adv7511->regmap_cec,
 				   ADV7511_REG_CEC_LOG_ADDR_MASK + offset,
 				   0x70, 0);
 		adv7511->cec_valid_addrs = 0;
 		return 0;
 	}

 	for (i = 0; i < ADV7511_MAX_ADDRS; i++) {
 		bool is_valid = adv7511->cec_valid_addrs & (1 << i);

 		if (free_idx == ADV7511_MAX_ADDRS && !is_valid)
 			free_idx = i;
 		if (is_valid && adv7511->cec_addr[i] == addr)
 			return 0;
 	}
 	if (i == ADV7511_MAX_ADDRS) {
 		i = free_idx;
 		if (i == ADV7511_MAX_ADDRS)
 			return -ENXIO;
 	}
 	adv7511->cec_addr[i] = addr;
 	adv7511->cec_valid_addrs |= 1 << i;

 	switch (i) {
 	case 0:
 		/* enable address mask 0 */
 		regmap_update_bits(adv7511->regmap_cec,
 				   ADV7511_REG_CEC_LOG_ADDR_MASK + offset,
 				   0x10, 0x10);
 		/* set address for mask 0 */
 		regmap_update_bits(adv7511->regmap_cec,
 				   ADV7511_REG_CEC_LOG_ADDR_0_1 + offset,
 				   0x0f, addr);
 		break;
 	case 1:
 		/* enable address mask 1 */
 		regmap_update_bits(adv7511->regmap_cec,
 				   ADV7511_REG_CEC_LOG_ADDR_MASK + offset,
 				   0x20, 0x20);
 		/* set address for mask 1 */
 		regmap_update_bits(adv7511->regmap_cec,
 				   ADV7511_REG_CEC_LOG_ADDR_0_1 + offset,
 				   0xf0, addr << 4);
 		break;
 	case 2:
 		/* enable address mask 2 */
 		regmap_update_bits(adv7511->regmap_cec,
 				   ADV7511_REG_CEC_LOG_ADDR_MASK + offset,
 				   0x40, 0x40);
 		/* set address for mask 1 */
 		regmap_update_bits(adv7511->regmap_cec,
 				   ADV7511_REG_CEC_LOG_ADDR_2 + offset,
 				   0x0f, addr);
 		break;
 	}
 	return 0;
 }

 static int adv7511_cec_adap_transmit(struct cec_adapter *adap, u8 attempts,
 				     u32 signal_free_time, struct cec_msg *msg)
 {
 	struct adv7511 *adv7511 = cec_get_drvdata(adap);
 	unsigned int offset = adv7511->type == ADV7533 ?
 					ADV7533_REG_CEC_OFFSET : 0;
 	u8 len = msg->len;
 	unsigned int i;

 	/*
 	 * The number of retries is the number of attempts - 1, but retry
 	 * at least once. It's not clear if a value of 0 is allowed, so
 	 * let's do at least one retry.
 	 */
 	regmap_update_bits(adv7511->regmap_cec,
 			   ADV7511_REG_CEC_TX_RETRY + offset,
 			   0x70, max(1, attempts - 1) << 4);

 	/* blocking, clear cec tx irq status */
 	regmap_update_bits(adv7511->regmap, ADV7511_REG_INT(1), 0x38, 0x38);

 	/* write data */
 	for (i = 0; i < len; i++)
 		regmap_write(adv7511->regmap_cec,
 			     i + ADV7511_REG_CEC_TX_FRAME_HDR + offset,
 			     msg->msg[i]);

 	/* set length (data + header) */
 	regmap_write(adv7511->regmap_cec,
 		     ADV7511_REG_CEC_TX_FRAME_LEN + offset, len);
 	/* start transmit, enable tx */
 	regmap_write(adv7511->regmap_cec,
 		     ADV7511_REG_CEC_TX_ENABLE + offset, 0x01);
 	return 0;
 }

 static const struct cec_adap_ops adv7511_cec_adap_ops = {
 	.adap_enable = adv7511_cec_adap_enable,
 	.adap_log_addr = adv7511_cec_adap_log_addr,
 	.adap_transmit = adv7511_cec_adap_transmit,
 };

 static int adv7511_cec_parse_dt(struct device *dev, struct adv7511 *adv7511)
 {
 	adv7511->cec_clk = devm_clk_get(dev, "cec");
 	if (IS_ERR(adv7511->cec_clk)) {
 		int ret = PTR_ERR(adv7511->cec_clk);

 		adv7511->cec_clk = NULL;
 		return ret;
 	}
 	clk_prepare_enable(adv7511->cec_clk);
 	adv7511->cec_clk_freq = clk_get_rate(adv7511->cec_clk);
 	return 0;
 }

 int adv7511_cec_init(struct device *dev, struct adv7511 *adv7511)
 {
 	unsigned int offset = adv7511->type == ADV7533 ?
 						ADV7533_REG_CEC_OFFSET : 0;
 	int ret = adv7511_cec_parse_dt(dev, adv7511);

 	if (ret)
 		goto err_cec_parse_dt;

 	adv7511->cec_adap = cec_allocate_adapter(&adv7511_cec_adap_ops,
 		adv7511, dev_name(dev), CEC_CAP_DEFAULTS, ADV7511_MAX_ADDRS);
 	if (IS_ERR(adv7511->cec_adap)) {
 		ret = PTR_ERR(adv7511->cec_adap);
 		goto err_cec_alloc;
 	}

 	regmap_write(adv7511->regmap, ADV7511_REG_CEC_CTRL + offset, 0);
 	/* cec soft reset */
 	regmap_write(adv7511->regmap_cec,
 		     ADV7511_REG_CEC_SOFT_RESET + offset, 0x01);
 	regmap_write(adv7511->regmap_cec,
 		     ADV7511_REG_CEC_SOFT_RESET + offset, 0x00);

 	/* legacy mode */
 	regmap_write(adv7511->regmap_cec,
 		     ADV7511_REG_CEC_RX_BUFFERS + offset, 0x00);

 	regmap_write(adv7511->regmap_cec,
 		     ADV7511_REG_CEC_CLK_DIV + offset,
 		     ((adv7511->cec_clk_freq / 750000) - 1) << 2);

 	ret = cec_register_adapter(adv7511->cec_adap, dev);
 	if (ret)
 		goto err_cec_register;
 	return 0;

 err_cec_register:
 	cec_delete_adapter(adv7511->cec_adap);
 	adv7511->cec_adap = NULL;
 err_cec_alloc:
 	dev_info(dev, "Initializing CEC failed with error %d, disabling CEC\n",
 		 ret);
 err_cec_parse_dt:
 	regmap_write(adv7511->regmap, ADV7511_REG_CEC_CTRL + offset,
 		     ADV7511_CEC_CTRL_POWER_DOWN);
 	return ret == -EPROBE_DEFER ? ret : 0;
 }
	/*
	* adv7511_cec.c - Analog Devices ADV7511/33 cec driver
	*
	* Copyright 2017 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
	*
	* This program is free software; you may redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; version 2 of the License.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
	* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
	* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
	* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
	* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
	* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
	* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	* SOFTWARE.
	*
	*/

	#include <linux/device.h>
	#include <linux/module.h>
	#include <linux/of_device.h>
	#include <linux/slab.h>
	#include <linux/clk.h>

	#include <media/cec.h>

	#include "adv7511.h"

	#define ADV7511_INT1_CEC_MASK \
	(ADV7511_INT1_CEC_TX_READY \| ADV7511_INT1_CEC_TX_ARBIT_LOST \| \
	ADV7511_INT1_CEC_TX_RETRY_TIMEOUT \| ADV7511_INT1_CEC_RX_READY1)

	static void adv_cec_tx_raw_status(struct adv7511 *adv7511, u8 tx_raw_status)
	{
	unsigned int offset = adv7511->type == ADV7533 ?
	ADV7533_REG_CEC_OFFSET : 0;
	unsigned int val;

	if (regmap_read(adv7511->regmap_cec,
	ADV7511_REG_CEC_TX_ENABLE + offset, &val))
	return;

	if ((val & 0x01) == 0)
	return;

	if (tx_raw_status & ADV7511_INT1_CEC_TX_ARBIT_LOST) {
	cec_transmit_attempt_done(adv7511->cec_adap,
	CEC_TX_STATUS_ARB_LOST);
	return;
	}
	if (tx_raw_status & ADV7511_INT1_CEC_TX_RETRY_TIMEOUT) {
	u8 status;
	u8 err_cnt = 0;
	u8 nack_cnt = 0;
	u8 low_drive_cnt = 0;
	unsigned int cnt;

	/*
	* We set this status bit since this hardware performs
	* retransmissions.
	*/
	status = CEC_TX_STATUS_MAX_RETRIES;
	if (regmap_read(adv7511->regmap_cec,
	ADV7511_REG_CEC_TX_LOW_DRV_CNT + offset, &cnt)) {
	err_cnt = 1;
	status \|= CEC_TX_STATUS_ERROR;
	} else {
	nack_cnt = cnt & 0xf;
	if (nack_cnt)
	status \|= CEC_TX_STATUS_NACK;
	low_drive_cnt = cnt >> 4;
	if (low_drive_cnt)
	status \|= CEC_TX_STATUS_LOW_DRIVE;
	}
	cec_transmit_done(adv7511->cec_adap, status,
	0, nack_cnt, low_drive_cnt, err_cnt);
	return;
	}
	if (tx_raw_status & ADV7511_INT1_CEC_TX_READY) {
	cec_transmit_attempt_done(adv7511->cec_adap, CEC_TX_STATUS_OK);
	return;
	}
	}

	void adv7511_cec_irq_process(struct adv7511 *adv7511, unsigned int irq1)
	{
	unsigned int offset = adv7511->type == ADV7533 ?
	ADV7533_REG_CEC_OFFSET : 0;
	const u32 irq_tx_mask = ADV7511_INT1_CEC_TX_READY \|
	ADV7511_INT1_CEC_TX_ARBIT_LOST \|
	ADV7511_INT1_CEC_TX_RETRY_TIMEOUT;
	struct cec_msg msg = {};
	unsigned int len;
	unsigned int val;
	u8 i;

	if (irq1 & irq_tx_mask)
	adv_cec_tx_raw_status(adv7511, irq1);

	if (!(irq1 & ADV7511_INT1_CEC_RX_READY1))
	return;

	if (regmap_read(adv7511->regmap_cec,
	ADV7511_REG_CEC_RX_FRAME_LEN + offset, &len))
	return;

	msg.len = len & 0x1f;

	if (msg.len > 16)
	msg.len = 16;

	if (!msg.len)
	return;

	for (i = 0; i < msg.len; i++) {
	regmap_read(adv7511->regmap_cec,
	i + ADV7511_REG_CEC_RX_FRAME_HDR + offset, &val);
	msg.msg[i] = val;
	}

	/* toggle to re-enable rx 1 */
	regmap_write(adv7511->regmap_cec,
	ADV7511_REG_CEC_RX_BUFFERS + offset, 1);
	regmap_write(adv7511->regmap_cec,
	ADV7511_REG_CEC_RX_BUFFERS + offset, 0);
	cec_received_msg(adv7511->cec_adap, &msg);
	}

	static int adv7511_cec_adap_enable(struct cec_adapter *adap, bool enable)
	{
	struct adv7511 *adv7511 = cec_get_drvdata(adap);
	unsigned int offset = adv7511->type == ADV7533 ?
	ADV7533_REG_CEC_OFFSET : 0;

	if (adv7511->i2c_cec == NULL)
	return -EIO;

	if (!adv7511->cec_enabled_adap && enable) {
	/* power up cec section */
	regmap_update_bits(adv7511->regmap_cec,
	ADV7511_REG_CEC_CLK_DIV + offset,
	0x03, 0x01);
	/* legacy mode and clear all rx buffers */
	regmap_write(adv7511->regmap_cec,
	ADV7511_REG_CEC_RX_BUFFERS + offset, 0x07);
	regmap_write(adv7511->regmap_cec,
	ADV7511_REG_CEC_RX_BUFFERS + offset, 0);
	/* initially disable tx */
	regmap_update_bits(adv7511->regmap_cec,
	ADV7511_REG_CEC_TX_ENABLE + offset, 1, 0);
	/* enabled irqs: */
	/* tx: ready */
	/* tx: arbitration lost */
	/* tx: retry timeout */
	/* rx: ready 1 */
	regmap_update_bits(adv7511->regmap,
	ADV7511_REG_INT_ENABLE(1), 0x3f,
	ADV7511_INT1_CEC_MASK);
	} else if (adv7511->cec_enabled_adap && !enable) {
	regmap_update_bits(adv7511->regmap,
	ADV7511_REG_INT_ENABLE(1), 0x3f, 0);
	/* disable address mask 1-3 */
	regmap_update_bits(adv7511->regmap_cec,
	ADV7511_REG_CEC_LOG_ADDR_MASK + offset,
	0x70, 0x00);
	/* power down cec section */
	regmap_update_bits(adv7511->regmap_cec,
	ADV7511_REG_CEC_CLK_DIV + offset,
	0x03, 0x00);
	adv7511->cec_valid_addrs = 0;
	}
	adv7511->cec_enabled_adap = enable;
	return 0;
	}

	static int adv7511_cec_adap_log_addr(struct cec_adapter *adap, u8 addr)
	{
	struct adv7511 *adv7511 = cec_get_drvdata(adap);
	unsigned int offset = adv7511->type == ADV7533 ?
	ADV7533_REG_CEC_OFFSET : 0;
	unsigned int i, free_idx = ADV7511_MAX_ADDRS;

	if (!adv7511->cec_enabled_adap)
	return addr == CEC_LOG_ADDR_INVALID ? 0 : -EIO;

	if (addr == CEC_LOG_ADDR_INVALID) {
	regmap_update_bits(adv7511->regmap_cec,
	ADV7511_REG_CEC_LOG_ADDR_MASK + offset,
	0x70, 0);
	adv7511->cec_valid_addrs = 0;
	return 0;
	}

	for (i = 0; i < ADV7511_MAX_ADDRS; i++) {
	bool is_valid = adv7511->cec_valid_addrs & (1 << i);

	if (free_idx == ADV7511_MAX_ADDRS && !is_valid)
	free_idx = i;
	if (is_valid && adv7511->cec_addr[i] == addr)
	return 0;
	}
	if (i == ADV7511_MAX_ADDRS) {
	i = free_idx;
	if (i == ADV7511_MAX_ADDRS)
	return -ENXIO;
	}
	adv7511->cec_addr[i] = addr;
	adv7511->cec_valid_addrs \|= 1 << i;

	switch (i) {
	case 0:
	/* enable address mask 0 */
	regmap_update_bits(adv7511->regmap_cec,
	ADV7511_REG_CEC_LOG_ADDR_MASK + offset,
	0x10, 0x10);
	/* set address for mask 0 */
	regmap_update_bits(adv7511->regmap_cec,
	ADV7511_REG_CEC_LOG_ADDR_0_1 + offset,
	0x0f, addr);
	break;
	case 1:
	/* enable address mask 1 */
	regmap_update_bits(adv7511->regmap_cec,
	ADV7511_REG_CEC_LOG_ADDR_MASK + offset,
	0x20, 0x20);
	/* set address for mask 1 */
	regmap_update_bits(adv7511->regmap_cec,
	ADV7511_REG_CEC_LOG_ADDR_0_1 + offset,
	0xf0, addr << 4);
	break;
	case 2:
	/* enable address mask 2 */
	regmap_update_bits(adv7511->regmap_cec,
	ADV7511_REG_CEC_LOG_ADDR_MASK + offset,
	0x40, 0x40);
	/* set address for mask 1 */
	regmap_update_bits(adv7511->regmap_cec,
	ADV7511_REG_CEC_LOG_ADDR_2 + offset,
	0x0f, addr);
	break;
	}
	return 0;
	}

	static int adv7511_cec_adap_transmit(struct cec_adapter *adap, u8 attempts,
	u32 signal_free_time, struct cec_msg *msg)
	{
	struct adv7511 *adv7511 = cec_get_drvdata(adap);
	unsigned int offset = adv7511->type == ADV7533 ?
	ADV7533_REG_CEC_OFFSET : 0;
	u8 len = msg->len;
	unsigned int i;

	/*
	* The number of retries is the number of attempts - 1, but retry
	* at least once. It's not clear if a value of 0 is allowed, so
	* let's do at least one retry.
	*/
	regmap_update_bits(adv7511->regmap_cec,
	ADV7511_REG_CEC_TX_RETRY + offset,
	0x70, max(1, attempts - 1) << 4);

	/* blocking, clear cec tx irq status */
	regmap_update_bits(adv7511->regmap, ADV7511_REG_INT(1), 0x38, 0x38);

	/* write data */
	for (i = 0; i < len; i++)
	regmap_write(adv7511->regmap_cec,
	i + ADV7511_REG_CEC_TX_FRAME_HDR + offset,
	msg->msg[i]);

	/* set length (data + header) */
	regmap_write(adv7511->regmap_cec,
	ADV7511_REG_CEC_TX_FRAME_LEN + offset, len);
	/* start transmit, enable tx */
	regmap_write(adv7511->regmap_cec,
	ADV7511_REG_CEC_TX_ENABLE + offset, 0x01);
	return 0;
	}

	static const struct cec_adap_ops adv7511_cec_adap_ops = {
	.adap_enable = adv7511_cec_adap_enable,
	.adap_log_addr = adv7511_cec_adap_log_addr,
	.adap_transmit = adv7511_cec_adap_transmit,
	};

	static int adv7511_cec_parse_dt(struct device dev, struct adv7511 adv7511)
	{
	adv7511->cec_clk = devm_clk_get(dev, "cec");
	if (IS_ERR(adv7511->cec_clk)) {
	int ret = PTR_ERR(adv7511->cec_clk);

	adv7511->cec_clk = NULL;
	return ret;
	}
	clk_prepare_enable(adv7511->cec_clk);
	adv7511->cec_clk_freq = clk_get_rate(adv7511->cec_clk);
	return 0;
	}

	int adv7511_cec_init(struct device dev, struct adv7511 adv7511)
	{
	unsigned int offset = adv7511->type == ADV7533 ?
	ADV7533_REG_CEC_OFFSET : 0;
	int ret = adv7511_cec_parse_dt(dev, adv7511);

	if (ret)
	goto err_cec_parse_dt;

	adv7511->cec_adap = cec_allocate_adapter(&adv7511_cec_adap_ops,
	adv7511, dev_name(dev), CEC_CAP_DEFAULTS, ADV7511_MAX_ADDRS);
	if (IS_ERR(adv7511->cec_adap)) {
	ret = PTR_ERR(adv7511->cec_adap);
	goto err_cec_alloc;
	}

	regmap_write(adv7511->regmap, ADV7511_REG_CEC_CTRL + offset, 0);
	/* cec soft reset */
	regmap_write(adv7511->regmap_cec,
	ADV7511_REG_CEC_SOFT_RESET + offset, 0x01);
	regmap_write(adv7511->regmap_cec,
	ADV7511_REG_CEC_SOFT_RESET + offset, 0x00);

	/* legacy mode */
	regmap_write(adv7511->regmap_cec,
	ADV7511_REG_CEC_RX_BUFFERS + offset, 0x00);

	regmap_write(adv7511->regmap_cec,
	ADV7511_REG_CEC_CLK_DIV + offset,
	((adv7511->cec_clk_freq / 750000) - 1) << 2);

	ret = cec_register_adapter(adv7511->cec_adap, dev);
	if (ret)
	goto err_cec_register;
	return 0;

	err_cec_register:
	cec_delete_adapter(adv7511->cec_adap);
	adv7511->cec_adap = NULL;
	err_cec_alloc:
	dev_info(dev, "Initializing CEC failed with error %d, disabling CEC\n",
	ret);
	err_cec_parse_dt:
	regmap_write(adv7511->regmap, ADV7511_REG_CEC_CTRL + offset,
	ADV7511_CEC_CTRL_POWER_DOWN);
	return ret == -EPROBE_DEFER ? ret : 0;
	}