Re: [PATCH 04/11] drm/bridge/synopsys: dw-hdmi: Export some PHY related functions

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Jernej,

Thank you for the patch.

On Saturday, 30 December 2017 23:01:56 EET Jernej Skrabec wrote:
> Parts of PHY code could be useful also for custom PHYs. For example,
> Allwinner A83T has custom PHY which is probably Synopsys gen2 PHY
> with few additional memory mapped registers, so most of the Synopsys PHY
> related code could be reused.
> 
> It turns out that even completely custom HDMI PHYs, such as the one
> found in Allwinner H3, can reuse some of those functions. This would
> suggest that (some?) functions exported in this commit are actually part
> of generic PHY interface and not really specific to Synopsys PHYs.

That's correct, those functions control the interface between the HDMI 
controller and the PHY. They're not specific to Synopsys PHYs, but they're 
specific to the PHY interface as designed by Synopsys.

> Export useful PHY functions.
> 
> Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
> ---
>  drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 45 ++++++++++++++++++++-------
>  drivers/gpu/drm/bridge/synopsys/dw-hdmi.h |  2 ++
>  include/drm/bridge/dw_hdmi.h              | 10 +++++++
>  3 files changed, 44 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c index
> 7ca14d7325b5..67467d0b683a 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> @@ -1037,19 +1037,21 @@ static void dw_hdmi_phy_enable_svsret(struct dw_hdmi
> *hdmi, u8 enable) HDMI_PHY_CONF0_SVSRET_MASK);
>  }
> 
> -static void dw_hdmi_phy_gen2_pddq(struct dw_hdmi *hdmi, u8 enable)
> +void dw_hdmi_phy_gen2_pddq(struct dw_hdmi *hdmi, u8 enable)
>  {
>  	hdmi_mask_writeb(hdmi, enable, HDMI_PHY_CONF0,
>  			 HDMI_PHY_CONF0_GEN2_PDDQ_OFFSET,
>  			 HDMI_PHY_CONF0_GEN2_PDDQ_MASK);
>  }
> +EXPORT_SYMBOL_GPL(dw_hdmi_phy_gen2_pddq);
> 
> -static void dw_hdmi_phy_gen2_txpwron(struct dw_hdmi *hdmi, u8 enable)
> +void dw_hdmi_phy_gen2_txpwron(struct dw_hdmi *hdmi, u8 enable)
>  {
>  	hdmi_mask_writeb(hdmi, enable, HDMI_PHY_CONF0,
>  			 HDMI_PHY_CONF0_GEN2_TXPWRON_OFFSET,
>  			 HDMI_PHY_CONF0_GEN2_TXPWRON_MASK);
>  }
> +EXPORT_SYMBOL_GPL(dw_hdmi_phy_gen2_txpwron);
> 
>  static void dw_hdmi_phy_sel_data_en_pol(struct dw_hdmi *hdmi, u8 enable)
>  {
> @@ -1065,6 +1067,23 @@ static void dw_hdmi_phy_sel_interface_control(struct
> dw_hdmi *hdmi, u8 enable) HDMI_PHY_CONF0_SELDIPIF_MASK);
>  }
> 
> +void dw_hdmi_phy_gen2_reset(struct dw_hdmi *hdmi, u8 enable)
> +{
> +	hdmi_mask_writeb(hdmi, enable, HDMI_MC_PHYRSTZ,
> +			 HDMI_MC_PHYRSTZ_PHYRSTZ_OFFSET,
> +			 HDMI_MC_PHYRSTZ_PHYRSTZ_MASK);
> +}
> +EXPORT_SYMBOL_GPL(dw_hdmi_phy_gen2_reset);
> +
> +void dw_hdmi_phy_set_slave_addr(struct dw_hdmi *hdmi)
> +{
> +	hdmi_phy_test_clear(hdmi, 1);
> +	hdmi_writeb(hdmi, HDMI_PHY_I2CM_SLAVE_ADDR_PHY_GEN2,
> +		    HDMI_PHY_I2CM_SLAVE_ADDR);
> +	hdmi_phy_test_clear(hdmi, 0);
> +}
> +EXPORT_SYMBOL_GPL(dw_hdmi_phy_set_slave_addr);

Should the I2C address be passed as an argument ?

>  static void dw_hdmi_phy_power_off(struct dw_hdmi *hdmi)
>  {
>  	const struct dw_hdmi_phy_data *phy = hdmi->phy.data;
> @@ -1204,15 +1223,12 @@ static int hdmi_phy_configure(struct dw_hdmi *hdmi)
>  		dw_hdmi_phy_enable_svsret(hdmi, 1);
> 
>  	/* PHY reset. The reset signal is active high on Gen2 PHYs. */
> -	hdmi_writeb(hdmi, HDMI_MC_PHYRSTZ_PHYRSTZ, HDMI_MC_PHYRSTZ);
> -	hdmi_writeb(hdmi, 0, HDMI_MC_PHYRSTZ);
> +	dw_hdmi_phy_gen2_reset(hdmi, 1);
> +	dw_hdmi_phy_gen2_reset(hdmi, 0);
> 
>  	hdmi_writeb(hdmi, HDMI_MC_HEACPHY_RST_ASSERT, HDMI_MC_HEACPHY_RST);
> 
> -	hdmi_phy_test_clear(hdmi, 1);
> -	hdmi_writeb(hdmi, HDMI_PHY_I2CM_SLAVE_ADDR_PHY_GEN2,
> -		    HDMI_PHY_I2CM_SLAVE_ADDR);
> -	hdmi_phy_test_clear(hdmi, 0);
> +	dw_hdmi_phy_set_slave_addr(hdmi);
> 
>  	/* Write to the PHY as configured by the platform */
>  	if (pdata->configure_phy)
> @@ -1251,15 +1267,16 @@ static void dw_hdmi_phy_disable(struct dw_hdmi
> *hdmi, void *data) dw_hdmi_phy_power_off(hdmi);
>  }
> 
> -static enum drm_connector_status dw_hdmi_phy_read_hpd(struct dw_hdmi *hdmi,
> -						      void *data)
> +enum drm_connector_status dw_hdmi_phy_read_hpd(struct dw_hdmi *hdmi,
> +					       void *data)
>  {
>  	return hdmi_readb(hdmi, HDMI_PHY_STAT0) & HDMI_PHY_HPD ?
>  		connector_status_connected : connector_status_disconnected;
>  }
> +EXPORT_SYMBOL_GPL(dw_hdmi_phy_read_hpd);
> 
> -static void dw_hdmi_phy_update_hpd(struct dw_hdmi *hdmi, void *data,
> -				   bool force, bool disabled, bool rxsense)
> +void dw_hdmi_phy_update_hpd(struct dw_hdmi *hdmi, void *data,
> +			    bool force, bool disabled, bool rxsense)
>  {
>  	u8 old_mask = hdmi->phy_mask;
> 
> @@ -1271,8 +1288,9 @@ static void dw_hdmi_phy_update_hpd(struct dw_hdmi
> *hdmi, void *data, if (old_mask != hdmi->phy_mask)
>  		hdmi_writeb(hdmi, hdmi->phy_mask, HDMI_PHY_MASK0);
>  }
> +EXPORT_SYMBOL_GPL(dw_hdmi_phy_update_hpd);
> 
> -static void dw_hdmi_phy_setup_hpd(struct dw_hdmi *hdmi, void *data)
> +void dw_hdmi_phy_setup_hpd(struct dw_hdmi *hdmi, void *data)
>  {
>  	/*
>  	 * Configure the PHY RX SENSE and HPD interrupts polarities and clear
> @@ -1291,6 +1309,7 @@ static void dw_hdmi_phy_setup_hpd(struct dw_hdmi
> *hdmi, void *data) hdmi_writeb(hdmi, ~(HDMI_IH_PHY_STAT0_HPD |
> HDMI_IH_PHY_STAT0_RX_SENSE), HDMI_IH_MUTE_PHY_STAT0);
>  }
> +EXPORT_SYMBOL_GPL(dw_hdmi_phy_setup_hpd);
> 
>  static const struct dw_hdmi_phy_ops dw_hdmi_synopsys_phy_ops = {
>  	.init = dw_hdmi_phy_init,
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.h
> b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.h index
> 9d90eb9c46e5..fd150430d0b3 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.h
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.h
> @@ -950,6 +950,8 @@ enum {
> 
>  /* MC_PHYRSTZ field values */
>  	HDMI_MC_PHYRSTZ_PHYRSTZ = 0x01,
> +	HDMI_MC_PHYRSTZ_PHYRSTZ_OFFSET = 0x00,
> +	HDMI_MC_PHYRSTZ_PHYRSTZ_MASK = 0x01,
> 
>  /* MC_HEACPHY_RST field values */
>  	HDMI_MC_HEACPHY_RST_ASSERT = 0x1,
> diff --git a/include/drm/bridge/dw_hdmi.h b/include/drm/bridge/dw_hdmi.h
> index 182f83283e24..f5cca4362154 100644
> --- a/include/drm/bridge/dw_hdmi.h
> +++ b/include/drm/bridge/dw_hdmi.h
> @@ -159,5 +159,15 @@ void dw_hdmi_audio_disable(struct dw_hdmi *hdmi);
>  /* PHY configuration */
>  void dw_hdmi_phy_i2c_write(struct dw_hdmi *hdmi, unsigned short data,
>  			   unsigned char addr);
> +enum drm_connector_status dw_hdmi_phy_read_hpd(struct dw_hdmi *hdmi,
> +					       void *data);
> +void dw_hdmi_phy_update_hpd(struct dw_hdmi *hdmi, void *data,
> +			    bool force, bool disabled, bool rxsense);
> +void dw_hdmi_phy_setup_hpd(struct dw_hdmi *hdmi, void *data);
> +
> +void dw_hdmi_phy_gen2_pddq(struct dw_hdmi *hdmi, u8 enable);
> +void dw_hdmi_phy_gen2_txpwron(struct dw_hdmi *hdmi, u8 enable);
> +void dw_hdmi_phy_gen2_reset(struct dw_hdmi *hdmi, u8 enable);
> +void dw_hdmi_phy_set_slave_addr(struct dw_hdmi *hdmi);
> 
>  #endif /* __IMX_HDMI_H__ */

-- 
Regards,

Laurent Pinchart