Re: [PATCH v3 1/2] drm: bridge: dw-hdmi: Add hook for resume

From: Sean Paul
Date: Thu Jun 06 2019 - 12:40:44 EST


On Tue, Jun 04, 2019 at 01:42:06PM -0700, Douglas Anderson wrote:
> On Rockchip rk3288-based Chromebooks when you do a suspend/resume
> cycle:
>
> 1. You lose the ability to detect an HDMI device being plugged in.
>
> 2. If you're using the i2c bus built in to dw_hdmi then it stops
> working.
>
> Let's add a hook to the core dw-hdmi driver so that we can call it in
> dw_hdmi-rockchip in the next commit.
>
> NOTE: the exact set of steps I've done here in resume come from
> looking at the normal dw_hdmi init sequence in upstream Linux plus the
> sequence that we did in downstream Chrome OS 3.14. Testing show that
> it seems to work, but if an extra step is needed or something here is
> not needed we could improve it.
>
> As part of this change we'll refactor the hardware init bits of
> dw-hdmi to happen all in one function and all at the same time. Since
> we need to init the interrupt mutes before we request the IRQ, this
> means moving the hardware init earlier in the function, but there
> should be no problems with that. Also as part of this we now
> unconditionally init the "i2c" parts of dw-hdmi, but again that ought
> to be fine.
>

Reviewed-by: Sean Paul <sean@xxxxxxxxxx>

> Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> ---
>
> Changes in v3:
> - Change resume to void function (Laurent)
>
> Changes in v2:
> - No empty stub for suspend (Laurent)
> - Refactor to use the same code in probe and resume (Laurent)
> - Unconditionally init i2c (seems OK + needed before hdmi->i2c init)
> - Combine "init" of i2c and "setup" of i2c (no reason to split)
>
> drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 48 ++++++++++++++---------
> include/drm/bridge/dw_hdmi.h | 2 +
> 2 files changed, 31 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> index 66bd66bad44c..a00ccf123877 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> @@ -228,6 +228,13 @@ static void hdmi_mask_writeb(struct dw_hdmi *hdmi, u8 data, unsigned int reg,
>
> static void dw_hdmi_i2c_init(struct dw_hdmi *hdmi)
> {
> + hdmi_writeb(hdmi, HDMI_PHY_I2CM_INT_ADDR_DONE_POL,
> + HDMI_PHY_I2CM_INT_ADDR);
> +
> + hdmi_writeb(hdmi, HDMI_PHY_I2CM_CTLINT_ADDR_NAC_POL |
> + HDMI_PHY_I2CM_CTLINT_ADDR_ARBITRATION_POL,
> + HDMI_PHY_I2CM_CTLINT_ADDR);
> +
> /* Software reset */
> hdmi_writeb(hdmi, 0x00, HDMI_I2CM_SOFTRSTZ);
>
> @@ -1926,16 +1933,6 @@ static int dw_hdmi_setup(struct dw_hdmi *hdmi, struct drm_display_mode *mode)
> return 0;
> }
>
> -static void dw_hdmi_setup_i2c(struct dw_hdmi *hdmi)
> -{
> - hdmi_writeb(hdmi, HDMI_PHY_I2CM_INT_ADDR_DONE_POL,
> - HDMI_PHY_I2CM_INT_ADDR);
> -
> - hdmi_writeb(hdmi, HDMI_PHY_I2CM_CTLINT_ADDR_NAC_POL |
> - HDMI_PHY_I2CM_CTLINT_ADDR_ARBITRATION_POL,
> - HDMI_PHY_I2CM_CTLINT_ADDR);
> -}
> -
> static void initialize_hdmi_ih_mutes(struct dw_hdmi *hdmi)
> {
> u8 ih_mute;
> @@ -2436,6 +2433,21 @@ static const struct regmap_config hdmi_regmap_32bit_config = {
> .max_register = HDMI_I2CM_FS_SCL_LCNT_0_ADDR << 2,
> };
>
> +static void dw_hdmi_init_hw(struct dw_hdmi *hdmi)
> +{
> + initialize_hdmi_ih_mutes(hdmi);
> +
> + /*
> + * Reset HDMI DDC I2C master controller and mute I2CM interrupts.
> + * Even if we are using a separate i2c adapter doing this doesn't
> + * hurt.
> + */
> + dw_hdmi_i2c_init(hdmi);
> +
> + if (hdmi->phy.ops->setup_hpd)
> + hdmi->phy.ops->setup_hpd(hdmi, hdmi->phy.data);
> +}
> +
> static struct dw_hdmi *
> __dw_hdmi_probe(struct platform_device *pdev,
> const struct dw_hdmi_plat_data *plat_data)
> @@ -2587,7 +2599,7 @@ __dw_hdmi_probe(struct platform_device *pdev,
> prod_id1 & HDMI_PRODUCT_ID1_HDCP ? "with" : "without",
> hdmi->phy.name);
>
> - initialize_hdmi_ih_mutes(hdmi);
> + dw_hdmi_init_hw(hdmi);
>
> irq = platform_get_irq(pdev, 0);
> if (irq < 0) {
> @@ -2626,10 +2638,6 @@ __dw_hdmi_probe(struct platform_device *pdev,
> hdmi->bridge.of_node = pdev->dev.of_node;
> #endif
>
> - dw_hdmi_setup_i2c(hdmi);
> - if (hdmi->phy.ops->setup_hpd)
> - hdmi->phy.ops->setup_hpd(hdmi, hdmi->phy.data);
> -
> memset(&pdevinfo, 0, sizeof(pdevinfo));
> pdevinfo.parent = dev;
> pdevinfo.id = PLATFORM_DEVID_AUTO;
> @@ -2682,10 +2690,6 @@ __dw_hdmi_probe(struct platform_device *pdev,
> hdmi->cec = platform_device_register_full(&pdevinfo);
> }
>
> - /* Reset HDMI DDC I2C master controller and mute I2CM interrupts */
> - if (hdmi->i2c)
> - dw_hdmi_i2c_init(hdmi);
> -
> return hdmi;
>
> err_iahb:
> @@ -2789,6 +2793,12 @@ void dw_hdmi_unbind(struct dw_hdmi *hdmi)
> }
> EXPORT_SYMBOL_GPL(dw_hdmi_unbind);
>
> +void dw_hdmi_resume(struct dw_hdmi *hdmi)
> +{
> + dw_hdmi_init_hw(hdmi);
> +}
> +EXPORT_SYMBOL_GPL(dw_hdmi_resume);
> +
> MODULE_AUTHOR("Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>");
> MODULE_AUTHOR("Andy Yan <andy.yan@xxxxxxxxxxxxxx>");
> MODULE_AUTHOR("Yakir Yang <ykk@xxxxxxxxxxxxxx>");
> diff --git a/include/drm/bridge/dw_hdmi.h b/include/drm/bridge/dw_hdmi.h
> index 66e70770cce5..601243b56b69 100644
> --- a/include/drm/bridge/dw_hdmi.h
> +++ b/include/drm/bridge/dw_hdmi.h
> @@ -154,6 +154,8 @@ struct dw_hdmi *dw_hdmi_bind(struct platform_device *pdev,
> struct drm_encoder *encoder,
> const struct dw_hdmi_plat_data *plat_data);
>
> +void dw_hdmi_resume(struct dw_hdmi *hdmi);
> +
> void dw_hdmi_setup_rx_sense(struct dw_hdmi *hdmi, bool hpd, bool rx_sense);
>
> void dw_hdmi_set_sample_rate(struct dw_hdmi *hdmi, unsigned int rate);
> --
> 2.22.0.rc1.311.g5d7573a151-goog
>

--
Sean Paul, Software Engineer, Google / Chromium OS