diff mbox series

[3/6] drm/bridge: extract some Analogix I2C DP common code

Message ID 20190523065352.8FD7668B05@newverein.lst.de (mailing list archive)
State New, archived
Headers show
Series Add anx6345 DP/eDP bridge for Olimex Teres-I | expand

Commit Message

Torsten Duwe May 23, 2019, 6:53 a.m. UTC 
From: Icenowy Zheng <icenowy@aosc.io>

Some code can be shared within different DP bridges by Analogix.

Extract them to a new module.

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
Signed-off-by: Torsten Duwe <duwe@suse.de>
---
 drivers/gpu/drm/bridge/analogix/Kconfig            |   4 +
 drivers/gpu/drm/bridge/analogix/Makefile           |   2 +
 drivers/gpu/drm/bridge/analogix/analogix-anx78xx.c | 146 +-----------------
 .../gpu/drm/bridge/analogix/analogix-i2c-dptx.c    | 169 +++++++++++++++++++++
 .../gpu/drm/bridge/analogix/analogix-i2c-dptx.h    |   2 +
 5 files changed, 178 insertions(+), 145 deletions(-)
 create mode 100644 drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.c

Comments

Chen-Yu Tsai May 23, 2019, 7:40 a.m. UTC | #1 
On Thu, May 23, 2019 at 2:54 PM Torsten Duwe <duwe@lst.de> wrote:
>
> From: Icenowy Zheng <icenowy@aosc.io>
>
> Some code can be shared within different DP bridges by Analogix.
>
> Extract them to a new module.
>
> Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
> Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
> Signed-off-by: Torsten Duwe <duwe@suse.de>
> ---
>  drivers/gpu/drm/bridge/analogix/Kconfig            |   4 +
>  drivers/gpu/drm/bridge/analogix/Makefile           |   2 +
>  drivers/gpu/drm/bridge/analogix/analogix-anx78xx.c | 146 +-----------------
>  .../gpu/drm/bridge/analogix/analogix-i2c-dptx.c    | 169 +++++++++++++++++++++
>  .../gpu/drm/bridge/analogix/analogix-i2c-dptx.h    |   2 +
>  5 files changed, 178 insertions(+), 145 deletions(-)
>  create mode 100644 drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.c
>

...

>  static int anx78xx_set_hpd(struct anx78xx *anx78xx)
> diff --git a/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.c b/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.c
> new file mode 100644
> index 000000000000..9cb30962032e
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.c
> @@ -0,0 +1,169 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright(c) 2017 Icenowy Zheng <icenowy@aosc.io>
> + *
> + * Based on analogix-anx78xx.c, which is:
> + *   Copyright(c) 2016, Analogix Semiconductor. All rights reserved.

If this was simple code movement, then the original copyright still applies.
A different copyright notice should not be used. I suppose the same applies
to the module author.

ChenYu
Laurent Pinchart May 23, 2019, 7:50 a.m. UTC | #2 
On Thu, May 23, 2019 at 03:40:25PM +0800, Chen-Yu Tsai wrote:
> On Thu, May 23, 2019 at 2:54 PM Torsten Duwe <duwe@lst.de> wrote:
> >
> > From: Icenowy Zheng <icenowy@aosc.io>
> >
> > Some code can be shared within different DP bridges by Analogix.
> >
> > Extract them to a new module.
> >
> > Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
> > Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
> > Signed-off-by: Torsten Duwe <duwe@suse.de>
> > ---
> >  drivers/gpu/drm/bridge/analogix/Kconfig            |   4 +
> >  drivers/gpu/drm/bridge/analogix/Makefile           |   2 +
> >  drivers/gpu/drm/bridge/analogix/analogix-anx78xx.c | 146 +-----------------
> >  .../gpu/drm/bridge/analogix/analogix-i2c-dptx.c    | 169 +++++++++++++++++++++
> >  .../gpu/drm/bridge/analogix/analogix-i2c-dptx.h    |   2 +
> >  5 files changed, 178 insertions(+), 145 deletions(-)
> >  create mode 100644 drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.c
> >
> 
> ...
> 
> >  static int anx78xx_set_hpd(struct anx78xx *anx78xx)
> > diff --git a/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.c b/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.c
> > new file mode 100644
> > index 000000000000..9cb30962032e
> > --- /dev/null
> > +++ b/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.c
> > @@ -0,0 +1,169 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright(c) 2017 Icenowy Zheng <icenowy@aosc.io>
> > + *
> > + * Based on analogix-anx78xx.c, which is:
> > + *   Copyright(c) 2016, Analogix Semiconductor. All rights reserved.
> 
> If this was simple code movement, then the original copyright still applies.
> A different copyright notice should not be used. I suppose the same applies
> to the module author.

And likely to patch 2/6 too.
Laurent Pinchart May 23, 2019, 7:54 a.m. UTC | #3 
Hi Torsten,

Thank you for the patch.

On Thu, May 23, 2019 at 08:53:52AM +0200, Torsten Duwe wrote:
> From: Icenowy Zheng <icenowy@aosc.io>
> 
> Some code can be shared within different DP bridges by Analogix.
> 
> Extract them to a new module.
> 
> Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
> Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
> Signed-off-by: Torsten Duwe <duwe@suse.de>
> ---
>  drivers/gpu/drm/bridge/analogix/Kconfig            |   4 +
>  drivers/gpu/drm/bridge/analogix/Makefile           |   2 +
>  drivers/gpu/drm/bridge/analogix/analogix-anx78xx.c | 146 +-----------------
>  .../gpu/drm/bridge/analogix/analogix-i2c-dptx.c    | 169 +++++++++++++++++++++
>  .../gpu/drm/bridge/analogix/analogix-i2c-dptx.h    |   2 +
>  5 files changed, 178 insertions(+), 145 deletions(-)
>  create mode 100644 drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.c
> 
> diff --git a/drivers/gpu/drm/bridge/analogix/Kconfig b/drivers/gpu/drm/bridge/analogix/Kconfig
> index c4d343a2f04d..ed2d05c12546 100644
> --- a/drivers/gpu/drm/bridge/analogix/Kconfig
> +++ b/drivers/gpu/drm/bridge/analogix/Kconfig
> @@ -1,6 +1,7 @@
>  # SPDX-License-Identifier: GPL-2.0-only
>  config DRM_ANALOGIX_ANX78XX
>  	tristate "Analogix ANX78XX bridge"
> +	select DRM_ANALOGIX_DP_I2C
>  	select DRM_KMS_HELPER
>  	select REGMAP_I2C
>  	help
> @@ -11,3 +12,6 @@ config DRM_ANALOGIX_ANX78XX
>  config DRM_ANALOGIX_DP
>  	tristate
>  	depends on DRM
> +
> +config DRM_ANALOGIX_DP_I2C
> +	tristate
> diff --git a/drivers/gpu/drm/bridge/analogix/Makefile b/drivers/gpu/drm/bridge/analogix/Makefile
> index ce1687e60975..2d523b67487d 100644
> --- a/drivers/gpu/drm/bridge/analogix/Makefile
> +++ b/drivers/gpu/drm/bridge/analogix/Makefile
> @@ -1,4 +1,6 @@
>  # SPDX-License-Identifier: GPL-2.0-only
>  analogix_dp-objs := analogix_dp_core.o analogix_dp_reg.o
> +analogix_dp_i2c-objs := analogix-i2c-dptx.o
>  obj-$(CONFIG_DRM_ANALOGIX_ANX78XX) += analogix-anx78xx.o
>  obj-$(CONFIG_DRM_ANALOGIX_DP) += analogix_dp.o
> +obj-$(CONFIG_DRM_ANALOGIX_DP_I2C) += analogix_dp_i2c.o

Do we need a separate module for this, or could it be included in
analogix_dp ?

> diff --git a/drivers/gpu/drm/bridge/analogix/analogix-anx78xx.c b/drivers/gpu/drm/bridge/analogix/analogix-anx78xx.c
> index f8433c93f463..bf8291d0ddd0 100644
> --- a/drivers/gpu/drm/bridge/analogix/analogix-anx78xx.c
> +++ b/drivers/gpu/drm/bridge/analogix/analogix-anx78xx.c
> @@ -45,8 +45,6 @@
>  #define I2C_IDX_RX_P1		4
>  
>  #define XTAL_CLK		270 /* 27M */
> -#define AUX_CH_BUFFER_SIZE	16
> -#define AUX_WAIT_TIMEOUT_MS	15
>  
>  static const u8 anx78xx_i2c_addresses[] = {
>  	[I2C_IDX_TX_P0] = TX_P0,
> @@ -109,153 +107,11 @@ static int anx78xx_clear_bits(struct regmap *map, u8 reg, u8 mask)
>  	return regmap_update_bits(map, reg, mask, 0);
>  }
>  
> -static bool anx78xx_aux_op_finished(struct anx78xx *anx78xx)
> -{
> -	unsigned int value;
> -	int err;
> -
> -	err = regmap_read(anx78xx->map[I2C_IDX_TX_P0], SP_DP_AUX_CH_CTRL2_REG,
> -			  &value);
> -	if (err < 0)
> -		return false;
> -
> -	return (value & SP_AUX_EN) == 0;
> -}
> -
> -static int anx78xx_aux_wait(struct anx78xx *anx78xx)
> -{
> -	unsigned long timeout;
> -	unsigned int status;
> -	int err;
> -
> -	timeout = jiffies + msecs_to_jiffies(AUX_WAIT_TIMEOUT_MS) + 1;
> -
> -	while (!anx78xx_aux_op_finished(anx78xx)) {
> -		if (time_after(jiffies, timeout)) {
> -			if (!anx78xx_aux_op_finished(anx78xx)) {
> -				DRM_ERROR("Timed out waiting AUX to finish\n");
> -				return -ETIMEDOUT;
> -			}
> -
> -			break;
> -		}
> -
> -		usleep_range(1000, 2000);
> -	}
> -
> -	/* Read the AUX channel access status */
> -	err = regmap_read(anx78xx->map[I2C_IDX_TX_P0], SP_AUX_CH_STATUS_REG,
> -			  &status);
> -	if (err < 0) {
> -		DRM_ERROR("Failed to read from AUX channel: %d\n", err);
> -		return err;
> -	}
> -
> -	if (status & SP_AUX_STATUS) {
> -		DRM_ERROR("Failed to wait for AUX channel (status: %02x)\n",
> -			  status);
> -		return -ETIMEDOUT;
> -	}
> -
> -	return 0;
> -}
> -
> -static int anx78xx_aux_address(struct anx78xx *anx78xx, unsigned int addr)
> -{
> -	int err;
> -
> -	err = regmap_write(anx78xx->map[I2C_IDX_TX_P0], SP_AUX_ADDR_7_0_REG,
> -			   addr & 0xff);
> -	if (err)
> -		return err;
> -
> -	err = regmap_write(anx78xx->map[I2C_IDX_TX_P0], SP_AUX_ADDR_15_8_REG,
> -			   (addr & 0xff00) >> 8);
> -	if (err)
> -		return err;
> -
> -	/*
> -	 * DP AUX CH Address Register #2, only update bits[3:0]
> -	 * [7:4] RESERVED
> -	 * [3:0] AUX_ADDR[19:16], Register control AUX CH address.
> -	 */
> -	err = regmap_update_bits(anx78xx->map[I2C_IDX_TX_P0],
> -				 SP_AUX_ADDR_19_16_REG,
> -				 SP_AUX_ADDR_19_16_MASK,
> -				 (addr & 0xf0000) >> 16);
> -
> -	if (err)
> -		return err;
> -
> -	return 0;
> -}
> -
>  static ssize_t anx78xx_aux_transfer(struct drm_dp_aux *aux,
>  				    struct drm_dp_aux_msg *msg)
>  {
>  	struct anx78xx *anx78xx = container_of(aux, struct anx78xx, aux);
> -	u8 ctrl1 = msg->request;
> -	u8 ctrl2 = SP_AUX_EN;
> -	u8 *buffer = msg->buffer;
> -	int err;
> -
> -	/* The DP AUX transmit and receive buffer has 16 bytes. */
> -	if (WARN_ON(msg->size > AUX_CH_BUFFER_SIZE))
> -		return -E2BIG;
> -
> -	/* Zero-sized messages specify address-only transactions. */
> -	if (msg->size < 1)
> -		ctrl2 |= SP_ADDR_ONLY;
> -	else	/* For non-zero-sized set the length field. */
> -		ctrl1 |= (msg->size - 1) << SP_AUX_LENGTH_SHIFT;
> -
> -	if ((msg->request & DP_AUX_I2C_READ) == 0) {
> -		/* When WRITE | MOT write values to data buffer */
> -		err = regmap_bulk_write(anx78xx->map[I2C_IDX_TX_P0],
> -					SP_DP_BUF_DATA0_REG, buffer,
> -					msg->size);
> -		if (err)
> -			return err;
> -	}
> -
> -	/* Write address and request */
> -	err = anx78xx_aux_address(anx78xx, msg->address);
> -	if (err)
> -		return err;
> -
> -	err = regmap_write(anx78xx->map[I2C_IDX_TX_P0], SP_DP_AUX_CH_CTRL1_REG,
> -			   ctrl1);
> -	if (err)
> -		return err;
> -
> -	/* Start transaction */
> -	err = regmap_update_bits(anx78xx->map[I2C_IDX_TX_P0],
> -				 SP_DP_AUX_CH_CTRL2_REG, SP_ADDR_ONLY |
> -				 SP_AUX_EN, ctrl2);
> -	if (err)
> -		return err;
> -
> -	err = anx78xx_aux_wait(anx78xx);
> -	if (err)
> -		return err;
> -
> -	msg->reply = DP_AUX_I2C_REPLY_ACK;
> -
> -	if ((msg->size > 0) && (msg->request & DP_AUX_I2C_READ)) {
> -		/* Read values from data buffer */
> -		err = regmap_bulk_read(anx78xx->map[I2C_IDX_TX_P0],
> -				       SP_DP_BUF_DATA0_REG, buffer,
> -				       msg->size);
> -		if (err)
> -			return err;
> -	}
> -
> -	err = anx78xx_clear_bits(anx78xx->map[I2C_IDX_TX_P0],
> -				 SP_DP_AUX_CH_CTRL2_REG, SP_ADDR_ONLY);
> -	if (err)
> -		return err;
> -
> -	return msg->size;
> +	return anx_aux_transfer(anx78xx->map[I2C_IDX_TX_P0], msg);
>  }
>  
>  static int anx78xx_set_hpd(struct anx78xx *anx78xx)
> diff --git a/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.c b/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.c
> new file mode 100644
> index 000000000000..9cb30962032e
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.c
> @@ -0,0 +1,169 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright(c) 2017 Icenowy Zheng <icenowy@aosc.io>
> + *
> + * Based on analogix-anx78xx.c, which is:
> + *   Copyright(c) 2016, Analogix Semiconductor. All rights reserved.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/regmap.h>
> +
> +#include <drm/drm.h>
> +#include <drm/drmP.h>
> +#include <drm/drm_dp_helper.h>
> +
> +#include "analogix-i2c-dptx.h"
> +
> +#define AUX_WAIT_TIMEOUT_MS	15
> +#define AUX_CH_BUFFER_SIZE	16
> +
> +static int anx_clear_bits(struct regmap *map, u8 reg, u8 mask)
> +{
> +	return regmap_update_bits(map, reg, mask, 0);
> +}
> +
> +static bool anx_aux_op_finished(struct regmap *map_dptx)
> +{
> +	unsigned int value;
> +	int err;
> +
> +	err = regmap_read(map_dptx, SP_DP_AUX_CH_CTRL2_REG, &value);
> +	if (err < 0)
> +		return false;
> +
> +	return (value & SP_AUX_EN) == 0;
> +}
> +
> +static int anx_aux_wait(struct regmap *map_dptx)
> +{
> +	unsigned long timeout;
> +	unsigned int status;
> +	int err;
> +
> +	timeout = jiffies + msecs_to_jiffies(AUX_WAIT_TIMEOUT_MS) + 1;
> +
> +	while (!anx_aux_op_finished(map_dptx)) {
> +		if (time_after(jiffies, timeout)) {
> +			if (!anx_aux_op_finished(map_dptx)) {
> +				DRM_ERROR("Timed out waiting AUX to finish\n");
> +				return -ETIMEDOUT;
> +			}
> +
> +			break;
> +		}
> +
> +		usleep_range(1000, 2000);
> +	}
> +
> +	/* Read the AUX channel access status */
> +	err = regmap_read(map_dptx, SP_AUX_CH_STATUS_REG, &status);
> +	if (err < 0) {
> +		DRM_ERROR("Failed to read from AUX channel: %d\n", err);
> +		return err;
> +	}
> +
> +	if (status & SP_AUX_STATUS) {
> +		DRM_ERROR("Failed to wait for AUX channel (status: %02x)\n",
> +			  status);
> +		return -ETIMEDOUT;
> +	}
> +
> +	return 0;
> +}
> +
> +static int anx_aux_address(struct regmap *map_dptx, unsigned int addr)
> +{
> +	int err;
> +
> +	err = regmap_write(map_dptx, SP_AUX_ADDR_7_0_REG, addr & 0xff);
> +	if (err)
> +		return err;
> +
> +	err = regmap_write(map_dptx, SP_AUX_ADDR_15_8_REG,
> +			   (addr & 0xff00) >> 8);
> +	if (err)
> +		return err;
> +
> +	/*
> +	 * DP AUX CH Address Register #2, only update bits[3:0]
> +	 * [7:4] RESERVED
> +	 * [3:0] AUX_ADDR[19:16], Register control AUX CH address.
> +	 */
> +	err = regmap_update_bits(map_dptx, SP_AUX_ADDR_19_16_REG,
> +				 SP_AUX_ADDR_19_16_MASK,
> +				 (addr & 0xf0000) >> 16);
> +
> +	if (err)
> +		return err;
> +
> +	return 0;
> +}
> +
> +ssize_t anx_aux_transfer(struct regmap *map_dptx, struct drm_dp_aux_msg *msg)
> +{
> +	u8 ctrl1 = msg->request;
> +	u8 ctrl2 = SP_AUX_EN;
> +	u8 *buffer = msg->buffer;
> +	int err;
> +
> +	/* The DP AUX transmit and receive buffer has 16 bytes. */
> +	if (WARN_ON(msg->size > AUX_CH_BUFFER_SIZE))
> +		return -E2BIG;
> +
> +	/* Zero-sized messages specify address-only transactions. */
> +	if (msg->size < 1)
> +		ctrl2 |= SP_ADDR_ONLY;
> +	else	/* For non-zero-sized set the length field. */
> +		ctrl1 |= (msg->size - 1) << SP_AUX_LENGTH_SHIFT;
> +
> +	if ((msg->request & DP_AUX_I2C_READ) == 0) {
> +		/* When WRITE | MOT write values to data buffer */
> +		err = regmap_bulk_write(map_dptx,
> +					SP_DP_BUF_DATA0_REG, buffer,
> +					msg->size);
> +		if (err)
> +			return err;
> +	}
> +
> +	/* Write address and request */
> +	err = anx_aux_address(map_dptx, msg->address);
> +	if (err)
> +		return err;
> +
> +	err = regmap_write(map_dptx, SP_DP_AUX_CH_CTRL1_REG, ctrl1);
> +	if (err)
> +		return err;
> +
> +	/* Start transaction */
> +	err = regmap_update_bits(map_dptx, SP_DP_AUX_CH_CTRL2_REG,
> +				 SP_ADDR_ONLY | SP_AUX_EN, ctrl2);
> +	if (err)
> +		return err;
> +
> +	err = anx_aux_wait(map_dptx);
> +	if (err)
> +		return err;
> +
> +	msg->reply = DP_AUX_I2C_REPLY_ACK;
> +
> +	if ((msg->size > 0) && (msg->request & DP_AUX_I2C_READ)) {
> +		/* Read values from data buffer */
> +		err = regmap_bulk_read(map_dptx,
> +				       SP_DP_BUF_DATA0_REG, buffer,
> +				       msg->size);
> +		if (err)
> +			return err;
> +	}
> +
> +	err = anx_clear_bits(map_dptx, SP_DP_AUX_CH_CTRL2_REG, SP_ADDR_ONLY);
> +	if (err)
> +		return err;
> +
> +	return msg->size;
> +}
> +EXPORT_SYMBOL(anx_aux_transfer);

As the code license is GPL and the analogic DP core core is exported
with EXPORT_SYMBOL_GPL, should it be the case here too ?

> +
> +MODULE_DESCRIPTION("Analogix DisplayPort Transmitter common code");
> +MODULE_AUTHOR("Icenowy Zheng <icenowy@aosc.io>");
> +MODULE_LICENSE("GPL v2");
> diff --git a/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.h b/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.h
> index bc0831b127bf..c2ca854613a0 100644
> --- a/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.h
> +++ b/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.h
> @@ -245,4 +245,6 @@
>  /* DP AUX Buffer Data Registers */
>  #define SP_DP_BUF_DATA0_REG		0xf0
>  
> +ssize_t anx_aux_transfer(struct regmap *map_dptx, struct drm_dp_aux_msg *msg);

The name is a bit generic, should it be anx_dp_aux_transfer() ?

> +
>  #endif
Torsten Duwe May 23, 2019, 11:52 a.m. UTC | #4 
On Thu, May 23, 2019 at 10:50:35AM +0300, Laurent Pinchart wrote:
> On Thu, May 23, 2019 at 03:40:25PM +0800, Chen-Yu Tsai wrote:
> > 
> > If this was simple code movement, then the original copyright still applies.
> > A different copyright notice should not be used. I suppose the same applies
> > to the module author.
> 
> And likely to patch 2/6 too.

Absolutely correct. Wdiff does not lie.
Re-evaluating...

	Torsten
Sam Ravnborg May 27, 2019, 8:11 p.m. UTC | #5 
Hi Torsten.

> index 000000000000..9cb30962032e
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.c
> @@ -0,0 +1,169 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright(c) 2017 Icenowy Zheng <icenowy@aosc.io>
> + *
> + * Based on analogix-anx78xx.c, which is:
> + *   Copyright(c) 2016, Analogix Semiconductor. All rights reserved.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/regmap.h>
> +
> +#include <drm/drm.h>
> +#include <drm/drmP.h>

Can we please avoid drmP.h in new files.
The header file is deprecated and we try to get rid of it.

	Sam
diff mbox series

Patch

diff --git a/drivers/gpu/drm/bridge/analogix/Kconfig b/drivers/gpu/drm/bridge/analogix/Kconfig
index c4d343a2f04d..ed2d05c12546 100644
--- a/drivers/gpu/drm/bridge/analogix/Kconfig
+++ b/drivers/gpu/drm/bridge/analogix/Kconfig
@@ -1,6 +1,7 @@ 
 # SPDX-License-Identifier: GPL-2.0-only
 config DRM_ANALOGIX_ANX78XX
 	tristate "Analogix ANX78XX bridge"
+	select DRM_ANALOGIX_DP_I2C
 	select DRM_KMS_HELPER
 	select REGMAP_I2C
 	help
@@ -11,3 +12,6 @@  config DRM_ANALOGIX_ANX78XX
 config DRM_ANALOGIX_DP
 	tristate
 	depends on DRM
+
+config DRM_ANALOGIX_DP_I2C
+	tristate
diff --git a/drivers/gpu/drm/bridge/analogix/Makefile b/drivers/gpu/drm/bridge/analogix/Makefile
index ce1687e60975..2d523b67487d 100644
--- a/drivers/gpu/drm/bridge/analogix/Makefile
+++ b/drivers/gpu/drm/bridge/analogix/Makefile
@@ -1,4 +1,6 @@ 
 # SPDX-License-Identifier: GPL-2.0-only
 analogix_dp-objs := analogix_dp_core.o analogix_dp_reg.o
+analogix_dp_i2c-objs := analogix-i2c-dptx.o
 obj-$(CONFIG_DRM_ANALOGIX_ANX78XX) += analogix-anx78xx.o
 obj-$(CONFIG_DRM_ANALOGIX_DP) += analogix_dp.o
+obj-$(CONFIG_DRM_ANALOGIX_DP_I2C) += analogix_dp_i2c.o
diff --git a/drivers/gpu/drm/bridge/analogix/analogix-anx78xx.c b/drivers/gpu/drm/bridge/analogix/analogix-anx78xx.c
index f8433c93f463..bf8291d0ddd0 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix-anx78xx.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix-anx78xx.c
@@ -45,8 +45,6 @@ 
 #define I2C_IDX_RX_P1		4
 
 #define XTAL_CLK		270 /* 27M */
-#define AUX_CH_BUFFER_SIZE	16
-#define AUX_WAIT_TIMEOUT_MS	15
 
 static const u8 anx78xx_i2c_addresses[] = {
 	[I2C_IDX_TX_P0] = TX_P0,
@@ -109,153 +107,11 @@  static int anx78xx_clear_bits(struct regmap *map, u8 reg, u8 mask)
 	return regmap_update_bits(map, reg, mask, 0);
 }
 
-static bool anx78xx_aux_op_finished(struct anx78xx *anx78xx)
-{
-	unsigned int value;
-	int err;
-
-	err = regmap_read(anx78xx->map[I2C_IDX_TX_P0], SP_DP_AUX_CH_CTRL2_REG,
-			  &value);
-	if (err < 0)
-		return false;
-
-	return (value & SP_AUX_EN) == 0;
-}
-
-static int anx78xx_aux_wait(struct anx78xx *anx78xx)
-{
-	unsigned long timeout;
-	unsigned int status;
-	int err;
-
-	timeout = jiffies + msecs_to_jiffies(AUX_WAIT_TIMEOUT_MS) + 1;
-
-	while (!anx78xx_aux_op_finished(anx78xx)) {
-		if (time_after(jiffies, timeout)) {
-			if (!anx78xx_aux_op_finished(anx78xx)) {
-				DRM_ERROR("Timed out waiting AUX to finish\n");
-				return -ETIMEDOUT;
-			}
-
-			break;
-		}
-
-		usleep_range(1000, 2000);
-	}
-
-	/* Read the AUX channel access status */
-	err = regmap_read(anx78xx->map[I2C_IDX_TX_P0], SP_AUX_CH_STATUS_REG,
-			  &status);
-	if (err < 0) {
-		DRM_ERROR("Failed to read from AUX channel: %d\n", err);
-		return err;
-	}
-
-	if (status & SP_AUX_STATUS) {
-		DRM_ERROR("Failed to wait for AUX channel (status: %02x)\n",
-			  status);
-		return -ETIMEDOUT;
-	}
-
-	return 0;
-}
-
-static int anx78xx_aux_address(struct anx78xx *anx78xx, unsigned int addr)
-{
-	int err;
-
-	err = regmap_write(anx78xx->map[I2C_IDX_TX_P0], SP_AUX_ADDR_7_0_REG,
-			   addr & 0xff);
-	if (err)
-		return err;
-
-	err = regmap_write(anx78xx->map[I2C_IDX_TX_P0], SP_AUX_ADDR_15_8_REG,
-			   (addr & 0xff00) >> 8);
-	if (err)
-		return err;
-
-	/*
-	 * DP AUX CH Address Register #2, only update bits[3:0]
-	 * [7:4] RESERVED
-	 * [3:0] AUX_ADDR[19:16], Register control AUX CH address.
-	 */
-	err = regmap_update_bits(anx78xx->map[I2C_IDX_TX_P0],
-				 SP_AUX_ADDR_19_16_REG,
-				 SP_AUX_ADDR_19_16_MASK,
-				 (addr & 0xf0000) >> 16);
-
-	if (err)
-		return err;
-
-	return 0;
-}
-
 static ssize_t anx78xx_aux_transfer(struct drm_dp_aux *aux,
 				    struct drm_dp_aux_msg *msg)
 {
 	struct anx78xx *anx78xx = container_of(aux, struct anx78xx, aux);
-	u8 ctrl1 = msg->request;
-	u8 ctrl2 = SP_AUX_EN;
-	u8 *buffer = msg->buffer;
-	int err;
-
-	/* The DP AUX transmit and receive buffer has 16 bytes. */
-	if (WARN_ON(msg->size > AUX_CH_BUFFER_SIZE))
-		return -E2BIG;
-
-	/* Zero-sized messages specify address-only transactions. */
-	if (msg->size < 1)
-		ctrl2 |= SP_ADDR_ONLY;
-	else	/* For non-zero-sized set the length field. */
-		ctrl1 |= (msg->size - 1) << SP_AUX_LENGTH_SHIFT;
-
-	if ((msg->request & DP_AUX_I2C_READ) == 0) {
-		/* When WRITE | MOT write values to data buffer */
-		err = regmap_bulk_write(anx78xx->map[I2C_IDX_TX_P0],
-					SP_DP_BUF_DATA0_REG, buffer,
-					msg->size);
-		if (err)
-			return err;
-	}
-
-	/* Write address and request */
-	err = anx78xx_aux_address(anx78xx, msg->address);
-	if (err)
-		return err;
-
-	err = regmap_write(anx78xx->map[I2C_IDX_TX_P0], SP_DP_AUX_CH_CTRL1_REG,
-			   ctrl1);
-	if (err)
-		return err;
-
-	/* Start transaction */
-	err = regmap_update_bits(anx78xx->map[I2C_IDX_TX_P0],
-				 SP_DP_AUX_CH_CTRL2_REG, SP_ADDR_ONLY |
-				 SP_AUX_EN, ctrl2);
-	if (err)
-		return err;
-
-	err = anx78xx_aux_wait(anx78xx);
-	if (err)
-		return err;
-
-	msg->reply = DP_AUX_I2C_REPLY_ACK;
-
-	if ((msg->size > 0) && (msg->request & DP_AUX_I2C_READ)) {
-		/* Read values from data buffer */
-		err = regmap_bulk_read(anx78xx->map[I2C_IDX_TX_P0],
-				       SP_DP_BUF_DATA0_REG, buffer,
-				       msg->size);
-		if (err)
-			return err;
-	}
-
-	err = anx78xx_clear_bits(anx78xx->map[I2C_IDX_TX_P0],
-				 SP_DP_AUX_CH_CTRL2_REG, SP_ADDR_ONLY);
-	if (err)
-		return err;
-
-	return msg->size;
+	return anx_aux_transfer(anx78xx->map[I2C_IDX_TX_P0], msg);
 }
 
 static int anx78xx_set_hpd(struct anx78xx *anx78xx)
diff --git a/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.c b/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.c
new file mode 100644
index 000000000000..9cb30962032e
--- /dev/null
+++ b/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.c
@@ -0,0 +1,169 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright(c) 2017 Icenowy Zheng <icenowy@aosc.io>
+ *
+ * Based on analogix-anx78xx.c, which is:
+ *   Copyright(c) 2016, Analogix Semiconductor. All rights reserved.
+ */
+
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+#include <drm/drm.h>
+#include <drm/drmP.h>
+#include <drm/drm_dp_helper.h>
+
+#include "analogix-i2c-dptx.h"
+
+#define AUX_WAIT_TIMEOUT_MS	15
+#define AUX_CH_BUFFER_SIZE	16
+
+static int anx_clear_bits(struct regmap *map, u8 reg, u8 mask)
+{
+	return regmap_update_bits(map, reg, mask, 0);
+}
+
+static bool anx_aux_op_finished(struct regmap *map_dptx)
+{
+	unsigned int value;
+	int err;
+
+	err = regmap_read(map_dptx, SP_DP_AUX_CH_CTRL2_REG, &value);
+	if (err < 0)
+		return false;
+
+	return (value & SP_AUX_EN) == 0;
+}
+
+static int anx_aux_wait(struct regmap *map_dptx)
+{
+	unsigned long timeout;
+	unsigned int status;
+	int err;
+
+	timeout = jiffies + msecs_to_jiffies(AUX_WAIT_TIMEOUT_MS) + 1;
+
+	while (!anx_aux_op_finished(map_dptx)) {
+		if (time_after(jiffies, timeout)) {
+			if (!anx_aux_op_finished(map_dptx)) {
+				DRM_ERROR("Timed out waiting AUX to finish\n");
+				return -ETIMEDOUT;
+			}
+
+			break;
+		}
+
+		usleep_range(1000, 2000);
+	}
+
+	/* Read the AUX channel access status */
+	err = regmap_read(map_dptx, SP_AUX_CH_STATUS_REG, &status);
+	if (err < 0) {
+		DRM_ERROR("Failed to read from AUX channel: %d\n", err);
+		return err;
+	}
+
+	if (status & SP_AUX_STATUS) {
+		DRM_ERROR("Failed to wait for AUX channel (status: %02x)\n",
+			  status);
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+static int anx_aux_address(struct regmap *map_dptx, unsigned int addr)
+{
+	int err;
+
+	err = regmap_write(map_dptx, SP_AUX_ADDR_7_0_REG, addr & 0xff);
+	if (err)
+		return err;
+
+	err = regmap_write(map_dptx, SP_AUX_ADDR_15_8_REG,
+			   (addr & 0xff00) >> 8);
+	if (err)
+		return err;
+
+	/*
+	 * DP AUX CH Address Register #2, only update bits[3:0]
+	 * [7:4] RESERVED
+	 * [3:0] AUX_ADDR[19:16], Register control AUX CH address.
+	 */
+	err = regmap_update_bits(map_dptx, SP_AUX_ADDR_19_16_REG,
+				 SP_AUX_ADDR_19_16_MASK,
+				 (addr & 0xf0000) >> 16);
+
+	if (err)
+		return err;
+
+	return 0;
+}
+
+ssize_t anx_aux_transfer(struct regmap *map_dptx, struct drm_dp_aux_msg *msg)
+{
+	u8 ctrl1 = msg->request;
+	u8 ctrl2 = SP_AUX_EN;
+	u8 *buffer = msg->buffer;
+	int err;
+
+	/* The DP AUX transmit and receive buffer has 16 bytes. */
+	if (WARN_ON(msg->size > AUX_CH_BUFFER_SIZE))
+		return -E2BIG;
+
+	/* Zero-sized messages specify address-only transactions. */
+	if (msg->size < 1)
+		ctrl2 |= SP_ADDR_ONLY;
+	else	/* For non-zero-sized set the length field. */
+		ctrl1 |= (msg->size - 1) << SP_AUX_LENGTH_SHIFT;
+
+	if ((msg->request & DP_AUX_I2C_READ) == 0) {
+		/* When WRITE | MOT write values to data buffer */
+		err = regmap_bulk_write(map_dptx,
+					SP_DP_BUF_DATA0_REG, buffer,
+					msg->size);
+		if (err)
+			return err;
+	}
+
+	/* Write address and request */
+	err = anx_aux_address(map_dptx, msg->address);
+	if (err)
+		return err;
+
+	err = regmap_write(map_dptx, SP_DP_AUX_CH_CTRL1_REG, ctrl1);
+	if (err)
+		return err;
+
+	/* Start transaction */
+	err = regmap_update_bits(map_dptx, SP_DP_AUX_CH_CTRL2_REG,
+				 SP_ADDR_ONLY | SP_AUX_EN, ctrl2);
+	if (err)
+		return err;
+
+	err = anx_aux_wait(map_dptx);
+	if (err)
+		return err;
+
+	msg->reply = DP_AUX_I2C_REPLY_ACK;
+
+	if ((msg->size > 0) && (msg->request & DP_AUX_I2C_READ)) {
+		/* Read values from data buffer */
+		err = regmap_bulk_read(map_dptx,
+				       SP_DP_BUF_DATA0_REG, buffer,
+				       msg->size);
+		if (err)
+			return err;
+	}
+
+	err = anx_clear_bits(map_dptx, SP_DP_AUX_CH_CTRL2_REG, SP_ADDR_ONLY);
+	if (err)
+		return err;
+
+	return msg->size;
+}
+EXPORT_SYMBOL(anx_aux_transfer);
+
+MODULE_DESCRIPTION("Analogix DisplayPort Transmitter common code");
+MODULE_AUTHOR("Icenowy Zheng <icenowy@aosc.io>");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.h b/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.h
index bc0831b127bf..c2ca854613a0 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.h
+++ b/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.h
@@ -245,4 +245,6 @@ 
 /* DP AUX Buffer Data Registers */
 #define SP_DP_BUF_DATA0_REG		0xf0
 
+ssize_t anx_aux_transfer(struct regmap *map_dptx, struct drm_dp_aux_msg *msg);
+
 #endif