diff mbox

[2/2] cec: add STM32 cec driver

Message ID 1494925280-4527-3-git-send-email-benjamin.gaignard@linaro.org (mailing list archive)
State New, archived
Headers show

Commit Message

Benjamin Gaignard May 16, 2017, 9:01 a.m. UTC
This patch add cec driver for STM32 platforms.
cec hardware block isn't not always used with hdmi so
cec notifier is not implemented. That will be done later
when STM32 DSI driver will be available.

Driver compliance has been tested with cec-ctl and cec-compliance
tools.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
---
 drivers/media/platform/Kconfig           |  11 +
 drivers/media/platform/Makefile          |   2 +
 drivers/media/platform/stm32/Makefile    |   1 +
 drivers/media/platform/stm32/stm32-cec.c | 368 +++++++++++++++++++++++++++++++
 4 files changed, 382 insertions(+)
 create mode 100644 drivers/media/platform/stm32/Makefile
 create mode 100644 drivers/media/platform/stm32/stm32-cec.c

Comments

Hans Verkuil May 16, 2017, 9:33 a.m. UTC | #1
Hi Benjamin,

Thanks for the patch! Always nice to see new CEC drivers.

On 16/05/17 11:01, Benjamin Gaignard wrote:
> This patch add cec driver for STM32 platforms.
> cec hardware block isn't not always used with hdmi so
> cec notifier is not implemented. That will be done later
> when STM32 DSI driver will be available.
> 
> Driver compliance has been tested with cec-ctl and cec-compliance
> tools.
> 
> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>

Since Yannick wrote the original driver, shouldn't there be a Signed-off-by
from him as well?

> ---
>  drivers/media/platform/Kconfig           |  11 +
>  drivers/media/platform/Makefile          |   2 +
>  drivers/media/platform/stm32/Makefile    |   1 +
>  drivers/media/platform/stm32/stm32-cec.c | 368 +++++++++++++++++++++++++++++++
>  4 files changed, 382 insertions(+)
>  create mode 100644 drivers/media/platform/stm32/Makefile
>  create mode 100644 drivers/media/platform/stm32/stm32-cec.c
> 
> diff --git a/drivers/media/platform/Kconfig b/drivers/media/platform/Kconfig
> index ac026ee..72efe34 100644
> --- a/drivers/media/platform/Kconfig
> +++ b/drivers/media/platform/Kconfig
> @@ -519,4 +519,15 @@ config VIDEO_STI_HDMI_CEC
>           CEC bus is present in the HDMI connector and enables communication
>           between compatible devices.
>  
> +config VIDEO_STM32_HDMI_CEC
> +       tristate "STMicroelectronics STM32 HDMI CEC driver"
> +       depends on CEC_CORE && (ARCH_STM32 || COMPILE_TEST)
> +       select REGMAP
> +       select REGMAP_MMIO
> +       ---help---
> +         This is a driver for STM32 interface. It uses the
> +         generic CEC framework interface.
> +         CEC bus is present in the HDMI connector and enables communication
> +         between compatible devices.
> +
>  endif #CEC_PLATFORM_DRIVERS
> diff --git a/drivers/media/platform/Makefile b/drivers/media/platform/Makefile
> index 63303d6..7cd9965 100644
> --- a/drivers/media/platform/Makefile
> +++ b/drivers/media/platform/Makefile
> @@ -44,6 +44,8 @@ obj-$(CONFIG_VIDEO_STI_HDMI_CEC) 	+= sti/cec/
>  
>  obj-$(CONFIG_VIDEO_STI_DELTA)		+= sti/delta/
>  
> +obj-$(CONFIG_VIDEO_STM32_HDMI_CEC) 	+= stm32/
> +
>  obj-$(CONFIG_BLACKFIN)                  += blackfin/
>  
>  obj-$(CONFIG_ARCH_DAVINCI)		+= davinci/
> diff --git a/drivers/media/platform/stm32/Makefile b/drivers/media/platform/stm32/Makefile
> new file mode 100644
> index 0000000..632b04c
> --- /dev/null
> +++ b/drivers/media/platform/stm32/Makefile
> @@ -0,0 +1 @@
> +obj-$(CONFIG_VIDEO_STM32_HDMI_CEC) += stm32-cec.o
> diff --git a/drivers/media/platform/stm32/stm32-cec.c b/drivers/media/platform/stm32/stm32-cec.c
> new file mode 100644
> index 0000000..a40a6eb
> --- /dev/null
> +++ b/drivers/media/platform/stm32/stm32-cec.c
> @@ -0,0 +1,368 @@
> +/*
> + * STM32 CEC driver
> + * Copyright (C) STMicroelectronic SA 2017

Isn't it STMicroelectronics instead of STMicroelectronic?

> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/interrupt.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +
> +#include <media/cec.h>
> +
> +#define CEC_NAME	"stm32-cec"
> +
> +/* CEC registers  */
> +#define CEC_CR		0x0000 /* Control Register */
> +#define CEC_CFGR	0x0004 /* ConFiGuration Register */
> +#define CEC_TXDR	0x0008 /* Rx data Register */
> +#define CEC_RXDR	0x000C /* Rx data Register */
> +#define CEC_ISR		0x0010 /* Interrupt and status Register */
> +#define CEC_IER		0x0014 /* Interrupt enable Register */
> +
> +#define TXEOM		BIT(2)
> +#define TXSOM		BIT(1)
> +#define CECEN		BIT(0)
> +
> +#define LSTN		BIT(31)
> +#define OAR		GENMASK(30, 16)
> +#define SFTOP		BIT(8)
> +#define BRDNOGEN	BIT(7)
> +#define LBPEGEN		BIT(6)
> +#define BREGEN		BIT(5)
> +#define BRESTP		BIT(4)
> +#define RXTOL		BIT(3)
> +#define SFT		GENMASK(2, 0)
> +#define FULL_CFG	(LSTN | SFTOP | BRDNOGEN | LBPEGEN | BREGEN | BRESTP \
> +			 | RXTOL | SFT | BRDNOGEN)
> +
> +#define TXACKE		BIT(12)
> +#define TXERR		BIT(11)
> +#define TXUDR		BIT(10)
> +#define TXEND		BIT(9)
> +#define TXBR		BIT(8)
> +#define ARBLST		BIT(7)
> +#define RXACKE		BIT(6)
> +#define RXOVR		BIT(2)
> +#define RXEND		BIT(1)
> +#define RXBR		BIT(0)
> +
> +#define ALL_TX_IT	(TXEND | TXBR | TXACKE | TXERR | TXUDR | ARBLST)
> +#define ALL_RX_IT	(RXEND | RXBR | RXACKE | RXOVR)
> +
> +struct stm32_cec {
> +	struct cec_adapter	*adap;
> +	struct device		*dev;
> +	struct clk		*clk_cec;
> +	struct clk		*clk_hdmi_cec;
> +	struct reset_control	*rstc;
> +	struct regmap		*regmap;
> +	int			irq;
> +	u32			irq_status;
> +	u8			rx_msg[CEC_MAX_MSG_SIZE];
> +	u8			tx_msg[CEC_MAX_MSG_SIZE];
> +	int			rx_len;
> +	int			tx_len;
> +	int			tx_cnt;
> +};
> +
> +static void cec_hw_init(struct stm32_cec *cec)
> +{
> +	regmap_update_bits(cec->regmap, CEC_CR, TXEOM | TXSOM | CECEN, 0);
> +
> +	regmap_update_bits(cec->regmap, CEC_IER, ALL_TX_IT | ALL_RX_IT,
> +			   ALL_TX_IT | ALL_RX_IT);
> +
> +	regmap_update_bits(cec->regmap, CEC_CFGR, FULL_CFG, FULL_CFG);
> +}
> +
> +static void stm32_tx_done(struct stm32_cec *cec, u32 status)
> +{
> +	if (status & (TXERR | TXUDR)) {
> +		cec_transmit_done(cec->adap, CEC_TX_STATUS_ERROR,
> +				  0, 0, 0, 1);
> +		return;
> +	}
> +
> +	if (status & ARBLST) {
> +		cec_transmit_done(cec->adap, CEC_TX_STATUS_ARB_LOST,
> +				  1, 0, 0, 0);
> +		return;
> +	}
> +
> +	if (status & TXACKE) {
> +		cec_transmit_done(cec->adap, CEC_TX_STATUS_NACK,
> +				  0, 1, 0, 0);
> +		return;
> +	}
> +
> +	if (cec->irq_status & TXBR) {
> +		/* send next byte */
> +		if (cec->tx_cnt < cec->tx_len)
> +			regmap_write(cec->regmap, CEC_TXDR,
> +				     cec->tx_msg[cec->tx_cnt++]);
> +
> +		/* TXEOM is set to command transmission of the last byte */
> +		if (cec->tx_cnt == cec->tx_len)
> +			regmap_update_bits(cec->regmap, CEC_CR, TXEOM, TXEOM);
> +	}
> +
> +	if (cec->irq_status & TXEND)
> +		cec_transmit_done(cec->adap, CEC_TX_STATUS_OK, 0, 0, 0, 0);
> +}
> +
> +static void stm32_rx_done(struct stm32_cec *cec, u32 status)
> +{
> +	if (cec->irq_status & (RXACKE | RXOVR)) {
> +		cec->rx_len = 0;
> +		return;
> +	}
> +
> +	if (cec->irq_status & RXBR) {
> +		u32 val;
> +
> +		regmap_read(cec->regmap, CEC_RXDR, &val);
> +		cec->rx_msg[cec->rx_len++] = val & 0xFF;

Wouldn't it be safer to handle this IRQ and the TXBR interrupt in
stm32_cec_irq_handler()? This can be done in atomic context and these are
more time-sensitive.

> +	}
> +
> +	if (cec->irq_status & RXEND) {
> +		struct cec_msg msg = {};
> +
> +		msg.len = cec->rx_len;
> +		memcpy(msg.msg, cec->rx_msg, msg.len);

Most drivers just embed a cec_msg struct in the top-level struct (stm32_cec
in this case). That way there is no need to have your own copies of the length
and message data (rx_len and rx_msg in this case).

Actually, the same applies to the tx part, just embed a cec_msg tx_msg.

> +		cec_received_msg(cec->adap, &msg);
> +
> +		cec->rx_len = 0;
> +	}
> +}
> +
> +static irqreturn_t stm32_cec_irq_thread(int irq, void *arg)
> +{
> +	struct stm32_cec *cec = arg;
> +
> +	if (cec->irq_status & ALL_TX_IT)
> +		stm32_tx_done(cec, cec->irq_status);
> +
> +	if (cec->irq_status & ALL_RX_IT)
> +		stm32_rx_done(cec, cec->irq_status);
> +
> +	cec->irq_status = 0;
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static irqreturn_t stm32_cec_irq_handler(int irq, void *arg)
> +{
> +	struct stm32_cec *cec = arg;
> +
> +	regmap_read(cec->regmap, CEC_ISR, &cec->irq_status);
> +
> +	regmap_update_bits(cec->regmap, CEC_ISR,
> +			   ALL_TX_IT | ALL_RX_IT,
> +			   ALL_TX_IT | ALL_RX_IT);
> +
> +	return IRQ_WAKE_THREAD;
> +}
> +
> +static int stm32_cec_adap_enable(struct cec_adapter *adap, bool enable)
> +{
> +	struct stm32_cec *cec = adap->priv;
> +	int ret = 0;
> +
> +	if (enable) {
> +		ret = clk_enable(cec->clk_cec);
> +		if (ret)
> +			dev_err(cec->dev, "fail to enable cec clock\n");
> +
> +		clk_enable(cec->clk_hdmi_cec);
> +		regmap_update_bits(cec->regmap, CEC_CR, CECEN, CECEN);
> +	} else {
> +		clk_disable(cec->clk_cec);
> +		clk_disable(cec->clk_hdmi_cec);
> +		regmap_update_bits(cec->regmap, CEC_CR, CECEN, 0);
> +	}
> +
> +	return ret;
> +}
> +
> +static int stm32_cec_adap_log_addr(struct cec_adapter *adap, u8 logical_addr)
> +{
> +	struct stm32_cec *cec = adap->priv;
> +
> +	regmap_update_bits(cec->regmap, CEC_CR, CECEN, 0);
> +
> +	if (logical_addr == CEC_LOG_ADDR_INVALID)
> +		regmap_update_bits(cec->regmap, CEC_CFGR, OAR, 0);
> +	else
> +		regmap_update_bits(cec->regmap, CEC_CFGR, OAR,
> +				   (1 << logical_addr) << 16);

Since this is a mask I assume that this CEC implementation can handle multiple
logical addresses? In that case you should allow that when you call cec_allocate_adapter:
instead of '1' use CEC_MAX_LOG_ADDRS as the last argument.

> +
> +	regmap_update_bits(cec->regmap, CEC_CR, CECEN, CECEN);
> +
> +	return 0;
> +}
> +
> +static int stm32_cec_adap_transmit(struct cec_adapter *adap, u8 attempts,
> +				   u32 signal_free_time, struct cec_msg *msg)
> +{
> +	struct stm32_cec *cec = adap->priv;
> +
> +	/* Copy message */
> +	memcpy(cec->tx_msg, msg->msg, msg->len);
> +
> +	cec->tx_len = msg->len;
> +	cec->tx_cnt = 0;
> +
> +	/*
> +	 * If the CEC message consists of only one byte,
> +	 * TXEOM must be set before of TXSOM.
> +	 */
> +	if (cec->tx_len == 1)
> +		regmap_update_bits(cec->regmap, CEC_CR, TXEOM, TXEOM);
> +
> +	/* TXSOM is set to command transmission of the first byte */
> +	regmap_update_bits(cec->regmap, CEC_CR, TXSOM, TXSOM);
> +
> +	/* Write the header (first byte of message) */
> +	regmap_write(cec->regmap, CEC_TXDR, cec->tx_msg[0]);
> +	cec->tx_cnt++;
> +
> +	return 0;
> +}
> +
> +static const struct cec_adap_ops stm32_cec_adap_ops = {
> +	.adap_enable = stm32_cec_adap_enable,
> +	.adap_log_addr = stm32_cec_adap_log_addr,
> +	.adap_transmit = stm32_cec_adap_transmit,
> +};
> +
> +static const struct regmap_config stm32_cec_regmap_cfg = {
> +	.reg_bits = 32,
> +	.val_bits = 32,
> +	.reg_stride = sizeof(u32),
> +	.max_register = 0x14,
> +	.fast_io = true,
> +};
> +
> +static int stm32_cec_probe(struct platform_device *pdev)
> +{
> +	struct resource *res;
> +	struct stm32_cec *cec;
> +	void __iomem *mmio;
> +	int ret;
> +
> +	cec = devm_kzalloc(&pdev->dev, sizeof(*cec), GFP_KERNEL);
> +	if (!cec)
> +		return -ENOMEM;
> +
> +	cec->dev = &pdev->dev;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	mmio = devm_ioremap_resource(&pdev->dev, res);
> +	if (IS_ERR(mmio))
> +		return PTR_ERR(mmio);
> +
> +	cec->regmap = devm_regmap_init_mmio_clk(&pdev->dev, "cec", mmio,
> +						&stm32_cec_regmap_cfg);
> +
> +	if (IS_ERR(cec->regmap))
> +		return PTR_ERR(cec->regmap);
> +
> +	cec->irq = platform_get_irq(pdev, 0);
> +	if (cec->irq < 0)
> +		return cec->irq;
> +
> +	ret = devm_request_threaded_irq(&pdev->dev, cec->irq,
> +					stm32_cec_irq_handler,
> +					stm32_cec_irq_thread,
> +					0,
> +					pdev->name, cec);
> +	if (ret)
> +		return ret;
> +
> +	cec->clk_cec = devm_clk_get(&pdev->dev, "cec");
> +	if (IS_ERR(cec->clk_cec)) {
> +		dev_err(&pdev->dev, "Cannot get cec clock\n");
> +		return PTR_ERR(cec->clk_cec);
> +	}
> +
> +	ret = clk_prepare(cec->clk_cec);
> +	if (ret) {
> +		dev_err(&pdev->dev, "Unable to prepare cec clock\n");
> +		return ret;
> +	}
> +
> +	cec->clk_hdmi_cec = devm_clk_get(&pdev->dev, "hdmi-cec");
> +	if (!IS_ERR(cec->clk_hdmi_cec)) {
> +		ret = clk_prepare(cec->clk_hdmi_cec);
> +		if (ret) {
> +			dev_err(&pdev->dev, "Unable to prepare hdmi-cec clock\n");
> +			return ret;
> +		}
> +	}
> +
> +	cec->adap = cec_allocate_adapter(&stm32_cec_adap_ops, cec,
> +			CEC_NAME,
> +			CEC_CAP_LOG_ADDRS | CEC_CAP_PASSTHROUGH |
> +			CEC_CAP_PHYS_ADDR | CEC_CAP_TRANSMIT, 1);

Add CEC_CAP_RC.

Add a comment that CEC_CAP_PHYS_ADDR is temporary until this driver is
switched to using a cec_notifier.

There is no CEC bus monitoring support for this hardware?

> +	ret = PTR_ERR_OR_ZERO(cec->adap);
> +	if (ret)
> +		return ret;
> +
> +	ret = cec_register_adapter(cec->adap, &pdev->dev);
> +	if (ret) {
> +		cec_delete_adapter(cec->adap);
> +		return ret;
> +	}
> +
> +	cec_hw_init(cec);
> +
> +	platform_set_drvdata(pdev, cec);
> +
> +	return 0;
> +}
> +
> +static int stm32_cec_remove(struct platform_device *pdev)
> +{
> +	struct stm32_cec *cec = platform_get_drvdata(pdev);
> +
> +	clk_unprepare(cec->clk_cec);
> +	clk_unprepare(cec->clk_hdmi_cec);
> +
> +	cec_unregister_adapter(cec->adap);
> +
> +	cec_delete_adapter(cec->adap);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id stm32_cec_of_match[] = {
> +	{ .compatible = "st,stm32-cec" },
> +	{ /* end node */ }
> +};
> +MODULE_DEVICE_TABLE(of, stm32_cec_of_match);
> +
> +static struct platform_driver stm32_cec_driver = {
> +	.probe  = stm32_cec_probe,
> +	.remove = stm32_cec_remove,
> +	.driver = {
> +		.name		= CEC_NAME,
> +		.of_match_table = stm32_cec_of_match,
> +	},
> +};
> +
> +module_platform_driver(stm32_cec_driver);
> +
> +MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@st.com>");
> +MODULE_AUTHOR("Yannick Fertre <yannick.fertre@st.com>");
> +MODULE_DESCRIPTION("STMicroelectronics STM32 Consumer Electronics Control");
> +MODULE_LICENSE("GPL v2");
> 

Regards,

	Hans
diff mbox

Patch

diff --git a/drivers/media/platform/Kconfig b/drivers/media/platform/Kconfig
index ac026ee..72efe34 100644
--- a/drivers/media/platform/Kconfig
+++ b/drivers/media/platform/Kconfig
@@ -519,4 +519,15 @@  config VIDEO_STI_HDMI_CEC
          CEC bus is present in the HDMI connector and enables communication
          between compatible devices.
 
+config VIDEO_STM32_HDMI_CEC
+       tristate "STMicroelectronics STM32 HDMI CEC driver"
+       depends on CEC_CORE && (ARCH_STM32 || COMPILE_TEST)
+       select REGMAP
+       select REGMAP_MMIO
+       ---help---
+         This is a driver for STM32 interface. It uses the
+         generic CEC framework interface.
+         CEC bus is present in the HDMI connector and enables communication
+         between compatible devices.
+
 endif #CEC_PLATFORM_DRIVERS
diff --git a/drivers/media/platform/Makefile b/drivers/media/platform/Makefile
index 63303d6..7cd9965 100644
--- a/drivers/media/platform/Makefile
+++ b/drivers/media/platform/Makefile
@@ -44,6 +44,8 @@  obj-$(CONFIG_VIDEO_STI_HDMI_CEC) 	+= sti/cec/
 
 obj-$(CONFIG_VIDEO_STI_DELTA)		+= sti/delta/
 
+obj-$(CONFIG_VIDEO_STM32_HDMI_CEC) 	+= stm32/
+
 obj-$(CONFIG_BLACKFIN)                  += blackfin/
 
 obj-$(CONFIG_ARCH_DAVINCI)		+= davinci/
diff --git a/drivers/media/platform/stm32/Makefile b/drivers/media/platform/stm32/Makefile
new file mode 100644
index 0000000..632b04c
--- /dev/null
+++ b/drivers/media/platform/stm32/Makefile
@@ -0,0 +1 @@ 
+obj-$(CONFIG_VIDEO_STM32_HDMI_CEC) += stm32-cec.o
diff --git a/drivers/media/platform/stm32/stm32-cec.c b/drivers/media/platform/stm32/stm32-cec.c
new file mode 100644
index 0000000..a40a6eb
--- /dev/null
+++ b/drivers/media/platform/stm32/stm32-cec.c
@@ -0,0 +1,368 @@ 
+/*
+ * STM32 CEC driver
+ * Copyright (C) STMicroelectronic SA 2017
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include <media/cec.h>
+
+#define CEC_NAME	"stm32-cec"
+
+/* CEC registers  */
+#define CEC_CR		0x0000 /* Control Register */
+#define CEC_CFGR	0x0004 /* ConFiGuration Register */
+#define CEC_TXDR	0x0008 /* Rx data Register */
+#define CEC_RXDR	0x000C /* Rx data Register */
+#define CEC_ISR		0x0010 /* Interrupt and status Register */
+#define CEC_IER		0x0014 /* Interrupt enable Register */
+
+#define TXEOM		BIT(2)
+#define TXSOM		BIT(1)
+#define CECEN		BIT(0)
+
+#define LSTN		BIT(31)
+#define OAR		GENMASK(30, 16)
+#define SFTOP		BIT(8)
+#define BRDNOGEN	BIT(7)
+#define LBPEGEN		BIT(6)
+#define BREGEN		BIT(5)
+#define BRESTP		BIT(4)
+#define RXTOL		BIT(3)
+#define SFT		GENMASK(2, 0)
+#define FULL_CFG	(LSTN | SFTOP | BRDNOGEN | LBPEGEN | BREGEN | BRESTP \
+			 | RXTOL | SFT | BRDNOGEN)
+
+#define TXACKE		BIT(12)
+#define TXERR		BIT(11)
+#define TXUDR		BIT(10)
+#define TXEND		BIT(9)
+#define TXBR		BIT(8)
+#define ARBLST		BIT(7)
+#define RXACKE		BIT(6)
+#define RXOVR		BIT(2)
+#define RXEND		BIT(1)
+#define RXBR		BIT(0)
+
+#define ALL_TX_IT	(TXEND | TXBR | TXACKE | TXERR | TXUDR | ARBLST)
+#define ALL_RX_IT	(RXEND | RXBR | RXACKE | RXOVR)
+
+struct stm32_cec {
+	struct cec_adapter	*adap;
+	struct device		*dev;
+	struct clk		*clk_cec;
+	struct clk		*clk_hdmi_cec;
+	struct reset_control	*rstc;
+	struct regmap		*regmap;
+	int			irq;
+	u32			irq_status;
+	u8			rx_msg[CEC_MAX_MSG_SIZE];
+	u8			tx_msg[CEC_MAX_MSG_SIZE];
+	int			rx_len;
+	int			tx_len;
+	int			tx_cnt;
+};
+
+static void cec_hw_init(struct stm32_cec *cec)
+{
+	regmap_update_bits(cec->regmap, CEC_CR, TXEOM | TXSOM | CECEN, 0);
+
+	regmap_update_bits(cec->regmap, CEC_IER, ALL_TX_IT | ALL_RX_IT,
+			   ALL_TX_IT | ALL_RX_IT);
+
+	regmap_update_bits(cec->regmap, CEC_CFGR, FULL_CFG, FULL_CFG);
+}
+
+static void stm32_tx_done(struct stm32_cec *cec, u32 status)
+{
+	if (status & (TXERR | TXUDR)) {
+		cec_transmit_done(cec->adap, CEC_TX_STATUS_ERROR,
+				  0, 0, 0, 1);
+		return;
+	}
+
+	if (status & ARBLST) {
+		cec_transmit_done(cec->adap, CEC_TX_STATUS_ARB_LOST,
+				  1, 0, 0, 0);
+		return;
+	}
+
+	if (status & TXACKE) {
+		cec_transmit_done(cec->adap, CEC_TX_STATUS_NACK,
+				  0, 1, 0, 0);
+		return;
+	}
+
+	if (cec->irq_status & TXBR) {
+		/* send next byte */
+		if (cec->tx_cnt < cec->tx_len)
+			regmap_write(cec->regmap, CEC_TXDR,
+				     cec->tx_msg[cec->tx_cnt++]);
+
+		/* TXEOM is set to command transmission of the last byte */
+		if (cec->tx_cnt == cec->tx_len)
+			regmap_update_bits(cec->regmap, CEC_CR, TXEOM, TXEOM);
+	}
+
+	if (cec->irq_status & TXEND)
+		cec_transmit_done(cec->adap, CEC_TX_STATUS_OK, 0, 0, 0, 0);
+}
+
+static void stm32_rx_done(struct stm32_cec *cec, u32 status)
+{
+	if (cec->irq_status & (RXACKE | RXOVR)) {
+		cec->rx_len = 0;
+		return;
+	}
+
+	if (cec->irq_status & RXBR) {
+		u32 val;
+
+		regmap_read(cec->regmap, CEC_RXDR, &val);
+		cec->rx_msg[cec->rx_len++] = val & 0xFF;
+	}
+
+	if (cec->irq_status & RXEND) {
+		struct cec_msg msg = {};
+
+		msg.len = cec->rx_len;
+		memcpy(msg.msg, cec->rx_msg, msg.len);
+		cec_received_msg(cec->adap, &msg);
+
+		cec->rx_len = 0;
+	}
+}
+
+static irqreturn_t stm32_cec_irq_thread(int irq, void *arg)
+{
+	struct stm32_cec *cec = arg;
+
+	if (cec->irq_status & ALL_TX_IT)
+		stm32_tx_done(cec, cec->irq_status);
+
+	if (cec->irq_status & ALL_RX_IT)
+		stm32_rx_done(cec, cec->irq_status);
+
+	cec->irq_status = 0;
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t stm32_cec_irq_handler(int irq, void *arg)
+{
+	struct stm32_cec *cec = arg;
+
+	regmap_read(cec->regmap, CEC_ISR, &cec->irq_status);
+
+	regmap_update_bits(cec->regmap, CEC_ISR,
+			   ALL_TX_IT | ALL_RX_IT,
+			   ALL_TX_IT | ALL_RX_IT);
+
+	return IRQ_WAKE_THREAD;
+}
+
+static int stm32_cec_adap_enable(struct cec_adapter *adap, bool enable)
+{
+	struct stm32_cec *cec = adap->priv;
+	int ret = 0;
+
+	if (enable) {
+		ret = clk_enable(cec->clk_cec);
+		if (ret)
+			dev_err(cec->dev, "fail to enable cec clock\n");
+
+		clk_enable(cec->clk_hdmi_cec);
+		regmap_update_bits(cec->regmap, CEC_CR, CECEN, CECEN);
+	} else {
+		clk_disable(cec->clk_cec);
+		clk_disable(cec->clk_hdmi_cec);
+		regmap_update_bits(cec->regmap, CEC_CR, CECEN, 0);
+	}
+
+	return ret;
+}
+
+static int stm32_cec_adap_log_addr(struct cec_adapter *adap, u8 logical_addr)
+{
+	struct stm32_cec *cec = adap->priv;
+
+	regmap_update_bits(cec->regmap, CEC_CR, CECEN, 0);
+
+	if (logical_addr == CEC_LOG_ADDR_INVALID)
+		regmap_update_bits(cec->regmap, CEC_CFGR, OAR, 0);
+	else
+		regmap_update_bits(cec->regmap, CEC_CFGR, OAR,
+				   (1 << logical_addr) << 16);
+
+	regmap_update_bits(cec->regmap, CEC_CR, CECEN, CECEN);
+
+	return 0;
+}
+
+static int stm32_cec_adap_transmit(struct cec_adapter *adap, u8 attempts,
+				   u32 signal_free_time, struct cec_msg *msg)
+{
+	struct stm32_cec *cec = adap->priv;
+
+	/* Copy message */
+	memcpy(cec->tx_msg, msg->msg, msg->len);
+
+	cec->tx_len = msg->len;
+	cec->tx_cnt = 0;
+
+	/*
+	 * If the CEC message consists of only one byte,
+	 * TXEOM must be set before of TXSOM.
+	 */
+	if (cec->tx_len == 1)
+		regmap_update_bits(cec->regmap, CEC_CR, TXEOM, TXEOM);
+
+	/* TXSOM is set to command transmission of the first byte */
+	regmap_update_bits(cec->regmap, CEC_CR, TXSOM, TXSOM);
+
+	/* Write the header (first byte of message) */
+	regmap_write(cec->regmap, CEC_TXDR, cec->tx_msg[0]);
+	cec->tx_cnt++;
+
+	return 0;
+}
+
+static const struct cec_adap_ops stm32_cec_adap_ops = {
+	.adap_enable = stm32_cec_adap_enable,
+	.adap_log_addr = stm32_cec_adap_log_addr,
+	.adap_transmit = stm32_cec_adap_transmit,
+};
+
+static const struct regmap_config stm32_cec_regmap_cfg = {
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = sizeof(u32),
+	.max_register = 0x14,
+	.fast_io = true,
+};
+
+static int stm32_cec_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	struct stm32_cec *cec;
+	void __iomem *mmio;
+	int ret;
+
+	cec = devm_kzalloc(&pdev->dev, sizeof(*cec), GFP_KERNEL);
+	if (!cec)
+		return -ENOMEM;
+
+	cec->dev = &pdev->dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	mmio = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(mmio))
+		return PTR_ERR(mmio);
+
+	cec->regmap = devm_regmap_init_mmio_clk(&pdev->dev, "cec", mmio,
+						&stm32_cec_regmap_cfg);
+
+	if (IS_ERR(cec->regmap))
+		return PTR_ERR(cec->regmap);
+
+	cec->irq = platform_get_irq(pdev, 0);
+	if (cec->irq < 0)
+		return cec->irq;
+
+	ret = devm_request_threaded_irq(&pdev->dev, cec->irq,
+					stm32_cec_irq_handler,
+					stm32_cec_irq_thread,
+					0,
+					pdev->name, cec);
+	if (ret)
+		return ret;
+
+	cec->clk_cec = devm_clk_get(&pdev->dev, "cec");
+	if (IS_ERR(cec->clk_cec)) {
+		dev_err(&pdev->dev, "Cannot get cec clock\n");
+		return PTR_ERR(cec->clk_cec);
+	}
+
+	ret = clk_prepare(cec->clk_cec);
+	if (ret) {
+		dev_err(&pdev->dev, "Unable to prepare cec clock\n");
+		return ret;
+	}
+
+	cec->clk_hdmi_cec = devm_clk_get(&pdev->dev, "hdmi-cec");
+	if (!IS_ERR(cec->clk_hdmi_cec)) {
+		ret = clk_prepare(cec->clk_hdmi_cec);
+		if (ret) {
+			dev_err(&pdev->dev, "Unable to prepare hdmi-cec clock\n");
+			return ret;
+		}
+	}
+
+	cec->adap = cec_allocate_adapter(&stm32_cec_adap_ops, cec,
+			CEC_NAME,
+			CEC_CAP_LOG_ADDRS | CEC_CAP_PASSTHROUGH |
+			CEC_CAP_PHYS_ADDR | CEC_CAP_TRANSMIT, 1);
+	ret = PTR_ERR_OR_ZERO(cec->adap);
+	if (ret)
+		return ret;
+
+	ret = cec_register_adapter(cec->adap, &pdev->dev);
+	if (ret) {
+		cec_delete_adapter(cec->adap);
+		return ret;
+	}
+
+	cec_hw_init(cec);
+
+	platform_set_drvdata(pdev, cec);
+
+	return 0;
+}
+
+static int stm32_cec_remove(struct platform_device *pdev)
+{
+	struct stm32_cec *cec = platform_get_drvdata(pdev);
+
+	clk_unprepare(cec->clk_cec);
+	clk_unprepare(cec->clk_hdmi_cec);
+
+	cec_unregister_adapter(cec->adap);
+
+	cec_delete_adapter(cec->adap);
+
+	return 0;
+}
+
+static const struct of_device_id stm32_cec_of_match[] = {
+	{ .compatible = "st,stm32-cec" },
+	{ /* end node */ }
+};
+MODULE_DEVICE_TABLE(of, stm32_cec_of_match);
+
+static struct platform_driver stm32_cec_driver = {
+	.probe  = stm32_cec_probe,
+	.remove = stm32_cec_remove,
+	.driver = {
+		.name		= CEC_NAME,
+		.of_match_table = stm32_cec_of_match,
+	},
+};
+
+module_platform_driver(stm32_cec_driver);
+
+MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@st.com>");
+MODULE_AUTHOR("Yannick Fertre <yannick.fertre@st.com>");
+MODULE_DESCRIPTION("STMicroelectronics STM32 Consumer Electronics Control");
+MODULE_LICENSE("GPL v2");