Re: [PATCH v2 04/12] drm/bridge/synopsys: dw-hdmi: Export some PHY related functions

From: Laurent Pinchart
Date: Fri Jan 12 2018 - 18:05:00 EST

Hi Jernej,

Thank you for th epatch.

On Wednesday, 10 January 2018 21:25:04 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.
>
> Functions exported here are actually not specific to Synopsys PHYs but
> to DWC HDMI controller PHY interface. This means that even if the PHY is
> completely custom, i.e. not designed by Synopsys, exported functions can
> be useful.
>
> Signed-off-by: Jernej Skrabec <jernej.skrabec@xxxxxxxx>
> ---
> drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 44 ++++++++++++++++++++--------
> include/drm/bridge/dw_hdmi.h | 11 ++++++++
> 2 files changed, 41 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c index
> 7ca14d7325b5..7d80f4b56683 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 +1067,22 @@ static void dw_hdmi_phy_sel_interface_control(struct
> dw_hdmi *hdmi, u8 enable) HDMI_PHY_CONF0_SELDIPIF_MASK);
> }
>
> +void dw_hdmi_phy_reset(struct dw_hdmi *hdmi)
> +{
> + /* 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);
> +}
> +EXPORT_SYMBOL_GPL(dw_hdmi_phy_reset);
> +
> +void dw_hdmi_phy_i2c_set_addr(struct dw_hdmi *hdmi, u8 address)
> +{
> + hdmi_phy_test_clear(hdmi, 1);
> + hdmi_writeb(hdmi, address, HDMI_PHY_I2CM_SLAVE_ADDR);
> + hdmi_phy_test_clear(hdmi, 0);
> +}
> +EXPORT_SYMBOL_GPL(dw_hdmi_phy_i2c_set_addr);
> +
> static void dw_hdmi_phy_power_off(struct dw_hdmi *hdmi)
> {
> const struct dw_hdmi_phy_data *phy = hdmi->phy.data;
> @@ -1203,16 +1221,11 @@ static int hdmi_phy_configure(struct dw_hdmi *hdmi)
> if (phy->has_svsret)
> 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_reset(hdmi);
>
> 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_i2c_set_addr(hdmi, HDMI_PHY_I2CM_SLAVE_ADDR_PHY_GEN2);
>
> /* Write to the PHY as configured by the platform */
> if (pdata->configure_phy)
> @@ -1251,15 +1264,16 @@ 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 +1285,9 @@ 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 +1306,7 @@ 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/include/drm/bridge/dw_hdmi.h b/include/drm/bridge/dw_hdmi.h
> index 182f83283e24..4a35e5065f6f 100644
> --- a/include/drm/bridge/dw_hdmi.h
> +++ b/include/drm/bridge/dw_hdmi.h
> @@ -157,7 +157,18 @@ void dw_hdmi_audio_enable(struct dw_hdmi *hdmi);
> void dw_hdmi_audio_disable(struct dw_hdmi *hdmi);
>
> /* PHY configuration */
> +void dw_hdmi_phy_i2c_set_addr(struct dw_hdmi *hdmi, u8 address);
> 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_reset(struct dw_hdmi *hdmi);

Nitpicking, could you move these last three functions between the I2C and HPD
functions ? They are, as the I2C functions, related to controlling the
interface between the HDMI controller and the PHY (the internal I2C bus and
direct signals), so it would make sense to group them together.

With that fixed,

Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>

Regarding HPD I think we could refactor the code in a cleaner why that
wouldn't require the three functions to be exported, but that shouldn't block
this patch series, it can always be done later.

> #endif /* __IMX_HDMI_H__ */

--
Regards,

Laurent Pinchart