Re: [PATCH 8/8] drm: rcar-du: Add shutdown callback function in platform_driver

From: Daniel Vetter
Date: Thu Apr 04 2019 - 03:47:14 EST


On Wed, Apr 03, 2019 at 06:44:44PM +0530, VenkataRajesh.Kalakodima@xxxxxxxxxxxx wrote:
> From: kalakodima venkata rajesh <venkatarajesh.kalakodima@xxxxxxxxxxxx>
>
> When rebooting, the Display driver is accessing H/W (reading DDR).
> Therefore, there is a problem of hanging when setting DDR to self
> refresh mode.
>
> This patch implement the shutdown function and solve this problem
> by stopping H/W access.
>
> In addtion, on the ulcb board, since initial values of versaclock
> are used as they are, signals are not output when initializing to
> 0 with shutdown, so this patch excludes processing to initialize
> versaclock to 0.
> drm: rcar-du: Add HDMI control clock when S2RAM
>
> Signed-off-by: Koji Matsuoka <koji.matsuoka.xm@xxxxxxxxxxx>
>
> (cherry picked from horms/renesas-bsp commit 3cfda6331c4069800dd4434427284aba8e6f1ed6)
> [slongerbeam: keep integer i in rcar_du_pm_shutdown(), needed because of
> 050e54d87f ("drm: rcar-du: drm: rcar-du: Add DU CMM support")]
>
> Signed-off-by: Steve Longerbeam <steve_longerbeam@xxxxxxxxxx>

Maybe look into drm_atomic_helper_shutdown instead of hand-rolling? That
should disable all display related stuff for you.
-Daniel

>
> drm: rcar-du: cmm: lut and clu backup not required during
> shutdown
> rcar_du_cmm_pm_suspend function copies LUT and CLU hardare
> register values to memory. In the patch which adds DU CMM
> support (https://github.com/renesas-rcar/du_cmm/commit/
> 9a65d02119e4ae405a89a850463a6a0d0f2c1ecb), the intention of
> the author was to backup the registers during suspend and
> restore it on resume. But rcar_du_cmm_pm_suspend was also
> called on system shutdown. Though it does not cause any harm,
> it is not required during shutdown as it does not make sense
> to backup. This patch ensures that rcar_du_cmm_pm_suspend is
> called only during suspend
>
> Fixes: https://github.com/renesas-rcar/du_cmm/commit/9a65d02119e4ae405a89a850463a6a0d0f2c1ecb
>
> Signed-off-by: Balasubramani Vivekanandan <balasubramani_vivekanandan@xxxxxxxxxx>
>
> - Resolved checkpatch errors
> - Resolved merge conflicts according to latest version
>
> Signed-off-by: kalakodima venkata rajesh <venkatarajesh.kalakodima@xxxxxxxxxxxx>
> ---
> drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 35 ++++++++++++++++++++
> drivers/gpu/drm/rcar-du/rcar_du_drv.c | 54 +++++++++++++++++++++++++------
> drivers/gpu/drm/rcar-du/rcar_du_encoder.c | 2 +-
> drivers/gpu/drm/rcar-du/rcar_du_encoder.h | 1 +
> include/drm/bridge/dw_hdmi.h | 1 +
> 5 files changed, 83 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> index 5971976..aa257d7 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> @@ -2033,6 +2033,41 @@ static void dw_hdmi_bridge_enable(struct drm_bridge *bridge)
> mutex_unlock(&hdmi->mutex);
> }
>
> +/*
> + * This function controls clocks of dw_hdmi through drm_bridge
> + * at system suspend/resume.
> + * Arguments:
> + * bridge: drm_bridge that contains dw_hdmi.
> + * flag: controlled flag.
> + * false: is used when suspend.
> + * true: is used when resume.
> + */
> +void dw_hdmi_s2r_ctrl(struct drm_bridge *bridge, int flag)
> +{
> + struct dw_hdmi *hdmi = bridge->driver_private;
> +
> + if (!hdmi)
> + return;
> +
> + if (flag) { /* enable clk */
> + if (hdmi->isfr_clk)
> + clk_prepare_enable(hdmi->isfr_clk);
> + if (hdmi->iahb_clk)
> + clk_prepare_enable(hdmi->iahb_clk);
> +
> + initialize_hdmi_ih_mutes(hdmi);
> + dw_hdmi_setup_i2c(hdmi);
> + dw_hdmi_i2c_init(hdmi);
> + dw_hdmi_phy_setup_hpd(hdmi, NULL);
> + } else { /* disable clk */
> + if (hdmi->isfr_clk)
> + clk_disable_unprepare(hdmi->isfr_clk);
> + if (hdmi->iahb_clk)
> + clk_disable_unprepare(hdmi->iahb_clk);
> + }
> +}
> +EXPORT_SYMBOL_GPL(dw_hdmi_s2r_ctrl);
> +
> static const struct drm_bridge_funcs dw_hdmi_bridge_funcs = {
> .attach = dw_hdmi_bridge_attach,
> .enable = dw_hdmi_bridge_enable,
> diff --git a/drivers/gpu/drm/rcar-du/rcar_du_drv.c b/drivers/gpu/drm/rcar-du/rcar_du_drv.c
> index 838b7c9..9eb63b0 100644
> --- a/drivers/gpu/drm/rcar-du/rcar_du_drv.c
> +++ b/drivers/gpu/drm/rcar-du/rcar_du_drv.c
> @@ -21,6 +21,7 @@
> #include <linux/slab.h>
> #include <linux/wait.h>
>
> +#include <drm/bridge/dw_hdmi.h>
> #include <drm/drmP.h>
> #include <drm/drm_atomic_helper.h>
> #include <drm/drm_crtc_helper.h>
> @@ -368,18 +369,14 @@ static struct drm_driver rcar_du_driver = {
> */
>
> #ifdef CONFIG_PM_SLEEP
> -static int rcar_du_pm_suspend(struct device *dev)
> +static int rcar_du_pm_shutdown(struct device *dev)
> {
> struct rcar_du_device *rcdu = dev_get_drvdata(dev);
> struct drm_atomic_state *state;
> - int i;
> -
> - if (rcar_du_has(rcdu, RCAR_DU_FEATURE_CMM)) {
> - for (i = 0; i < rcdu->num_crtcs; ++i)
> - rcar_du_cmm_pm_suspend(&rcdu->crtcs[i]);
> - }
> -
> - drm_kms_helper_poll_disable(rcdu->ddev);
> +#if IS_ENABLED(CONFIG_DRM_RCAR_DW_HDMI)
> + struct drm_encoder *encoder;
> +#endif
> + drm_kms_helper_poll_disable(rcdu->ddev);
> drm_fbdev_cma_set_suspend_unlocked(rcdu->fbdev, true);
>
> state = drm_atomic_helper_suspend(rcdu->ddev);
> @@ -389,11 +386,43 @@ static int rcar_du_pm_suspend(struct device *dev)
> return PTR_ERR(state);
> }
>
> +#if IS_ENABLED(CONFIG_DRM_RCAR_DW_HDMI)
> + list_for_each_entry(encoder,
> + &rcdu->ddev->mode_config.encoder_list,
> + head) {
> + struct rcar_du_encoder *renc = to_rcar_encoder(encoder);
> +
> + if (renc->bridge && (renc->output == RCAR_DU_OUTPUT_HDMI0 ||
> + renc->output == RCAR_DU_OUTPUT_HDMI1))
> + dw_hdmi_s2r_ctrl(encoder->bridge, false);
> + }
> +#endif
> rcdu->suspend_state = state;
>
> return 0;
> }
>
> +static int rcar_du_pm_suspend(struct device *dev)
> +{
> + struct rcar_du_device *rcdu = dev_get_drvdata(dev);
> +
> + int i, ret;
> +
> + if (rcar_du_has(rcdu, RCAR_DU_FEATURE_CMM)) {
> + for (i = 0; i < rcdu->num_crtcs; ++i)
> + rcar_du_cmm_pm_suspend(&rcdu->crtcs[i]);
> + }
> +
> + ret = rcar_du_pm_shutdown(dev);
> +
> + if (ret)
> + return ret;
> +
> + for (i = 0; i < rcdu->num_crtcs; ++i)
> + clk_set_rate(rcdu->crtcs[i].extclock, 0);
> + return 0;
> +}
> +
> static int rcar_du_pm_resume(struct device *dev)
> {
> struct rcar_du_device *rcdu = dev_get_drvdata(dev);
> @@ -504,6 +533,12 @@ static int rcar_du_probe(struct platform_device *pdev)
> return ret;
> }
>
> +static void rcar_du_shutdown(struct platform_device *pdev)
> +{
> +#ifdef CONFIG_PM_SLEEP
> + rcar_du_pm_shutdown(&pdev->dev);
> +#endif
> +}
> static struct platform_driver rcar_du_platform_driver = {
> .probe = rcar_du_probe,
> .remove = rcar_du_remove,
> @@ -512,6 +547,7 @@ static struct platform_driver rcar_du_platform_driver = {
> .pm = &rcar_du_pm_ops,
> .of_match_table = rcar_du_of_table,
> },
> + .shutdown = rcar_du_shutdown,
> };
>
> static int __init rcar_du_init(void)
> diff --git a/drivers/gpu/drm/rcar-du/rcar_du_encoder.c b/drivers/gpu/drm/rcar-du/rcar_du_encoder.c
> index f9c933d..98df8a2 100644
> --- a/drivers/gpu/drm/rcar-du/rcar_du_encoder.c
> +++ b/drivers/gpu/drm/rcar-du/rcar_du_encoder.c
> @@ -62,7 +62,7 @@ int rcar_du_encoder_init(struct rcar_du_device *rcdu,
>
> dev_dbg(rcdu->dev, "initializing encoder %pOF for output %u\n",
> enc_node, output);
> -
> + renc->bridge = bridge;
> /* Locate the DRM bridge from the encoder DT node. */
> bridge = of_drm_find_bridge(enc_node);
> if (!bridge) {
> diff --git a/drivers/gpu/drm/rcar-du/rcar_du_encoder.h b/drivers/gpu/drm/rcar-du/rcar_du_encoder.h
> index 2d2abca..cc5bfcb 100644
> --- a/drivers/gpu/drm/rcar-du/rcar_du_encoder.h
> +++ b/drivers/gpu/drm/rcar-du/rcar_du_encoder.h
> @@ -23,6 +23,7 @@ struct rcar_du_device;
> struct rcar_du_encoder {
> struct drm_encoder base;
> enum rcar_du_output output;
> + struct drm_bridge *bridge;
> };
>
> #define to_rcar_encoder(e) \
> diff --git a/include/drm/bridge/dw_hdmi.h b/include/drm/bridge/dw_hdmi.h
> index ccb5aa8..36383cf4 100644
> --- a/include/drm/bridge/dw_hdmi.h
> +++ b/include/drm/bridge/dw_hdmi.h
> @@ -171,5 +171,6 @@ enum drm_connector_status dw_hdmi_phy_read_hpd(struct dw_hdmi *hdmi,
> 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_s2r_ctrl(struct drm_bridge *bridge, int flag);
>
> #endif /* __IMX_HDMI_H__ */
> --
> 2.7.4
>
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--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch