Re: [PATCH] drm/i915/ehl: Add support for DPLL4 (v8)

Souza, Jose
2019-06-27T00:14:25Z

On Fri, 2019-06-21 at 19:00 -0700, Vivek Kasireddy wrote:
> This patch adds support for DPLL4 on EHL that include the
> following restrictions:
>
> - DPLL4 cannot be used with DDIA (combo port A internal eDP usage).
> DPLL4 can be used with other DDIs, including DDID
> (combo port A external usage).
>
> - DPLL4 cannot be enabled when DC5 or DC6 are enabled.
>
> - The DPLL4 enable, lock, power enabled, and power state are
> connected
> to the MGPLL1_ENABLE register.
>
> v2: (suggestions from Bob Paauwe)
> - Rework ehl_get_dpll() function to call intel_find_shared_dpll() and
> iterate twice: once for Combo plls and once for MG plls.
>
> - Use MG pll funcs for DPLL4 instead of creating new ones and modify
> mg_pll_enable to include the restrictions for EHL.
>
> v3: Fix compilation error
>
> v4: (suggestions from Lucas and Ville)
> - Treat DPLL4 as a combo phy PLL and not as MG PLL
> - Disable DC states when this DPLL is being enabled
> - Reuse icl_get_dpll instead of creating a separate one for EHL
>
> v5: (suggestion from Ville)
> - Refcount the DC OFF power domains during the enabling and disabling
> of this DPLL.
>
> v6: rebase
>
> v7: (suggestion from Imre)
> - Add a new power domain instead of iterating over the domains
> assoicated with DC OFF power well.
>
> v8: (Ville and Imre)
> - Rename POWER_DOMAIN_DPLL4 TO POWER_DOMAIN_DPLL_DC_OFF
> - Grab a reference in intel_modeset_setup_hw_state() if this
> DPLL was already enabled perhaps by BIOS.
> - Check for the port type instead of the encoder
>

Reviewed-by: José Roberto de Souza <jose.souza@intel.com>

> Cc: José Roberto de Souza <jose.souza@intel.com>
> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> Cc: Matt Roper <matthew.d.roper@intel.com>
> Cc: Imre Deak <imre.deak@intel.com>
> Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
> ---
> drivers/gpu/drm/i915/display/intel_display.c | 6 +++
> .../drm/i915/display/intel_display_power.c | 3 ++
> .../drm/i915/display/intel_display_power.h | 1 +
> drivers/gpu/drm/i915/display/intel_dpll_mgr.c | 42
> +++++++++++++++++--
> drivers/gpu/drm/i915/display/intel_dpll_mgr.h | 6 +++
> 5 files changed, 55 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c
> b/drivers/gpu/drm/i915/display/intel_display.c
> index 8592a7d422de..a5f387e486ee 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -16778,6 +16778,12 @@ intel_modeset_setup_hw_state(struct
> drm_device *dev,
> for (i = 0; i < dev_priv->num_shared_dpll; i++) {
> struct intel_shared_dpll *pll = &dev_priv-
> >shared_dplls[i];
>
> + if (IS_ELKHARTLAKE(dev_priv) && pll->on &&
> + pll->info->id == DPLL_ID_EHL_DPLL4) {
> + pll->wakeref =
> intel_display_power_get(dev_priv,
> + POWER_DO
> MAIN_DPLL_DC_OFF);
> + }
> +
> if (!pll->on || pll->active_mask)
> continue;
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display_power.c
> b/drivers/gpu/drm/i915/display/intel_display_power.c
> index c93ad512014c..1c101a842331 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_power.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_power.c
> @@ -117,6 +117,8 @@ intel_display_power_domain_str(enum
> intel_display_power_domain domain)
> return "MODESET";
> case POWER_DOMAIN_GT_IRQ:
> return "GT_IRQ";
> + case POWER_DOMAIN_DPLL_DC_OFF:
> + return "DPLL_DC_OFF";
> default:
> MISSING_CASE(domain);
> return "?";
> @@ -2361,6 +2363,7 @@ void intel_display_power_put(struct
> drm_i915_private *dev_priv,
> ICL_PW_2_POWER_DOMAINS | \
> BIT_ULL(POWER_DOMAIN_MODESET) | \
> BIT_ULL(POWER_DOMAIN_AUX_A) | \
> + BIT_ULL(POWER_DOMAIN_DPLL_DC_OFF) | \
> BIT_ULL(POWER_DOMAIN_INIT))
>
> #define ICL_DDI_IO_A_POWER_DOMAINS ( \
> diff --git a/drivers/gpu/drm/i915/display/intel_display_power.h
> b/drivers/gpu/drm/i915/display/intel_display_power.h
> index ff57b0a7fe59..8f43f7051a16 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_power.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_power.h
> @@ -59,6 +59,7 @@ enum intel_display_power_domain {
> POWER_DOMAIN_GMBUS,
> POWER_DOMAIN_MODESET,
> POWER_DOMAIN_GT_IRQ,
> + POWER_DOMAIN_DPLL_DC_OFF,
> POWER_DOMAIN_INIT,
>
> POWER_DOMAIN_NUM,
> diff --git a/drivers/gpu/drm/i915/display/intel_dpll_mgr.c
> b/drivers/gpu/drm/i915/display/intel_dpll_mgr.c
> index 2d4e7b9a7b9d..81e1443cb583 100644
> --- a/drivers/gpu/drm/i915/display/intel_dpll_mgr.c
> +++ b/drivers/gpu/drm/i915/display/intel_dpll_mgr.c
> @@ -2806,6 +2806,10 @@ icl_get_dpll(struct intel_crtc_state
> *crtc_state,
> if (intel_port_is_combophy(dev_priv, port)) {
> min = DPLL_ID_ICL_DPLL0;
> max = DPLL_ID_ICL_DPLL1;
> +
> + if (IS_ELKHARTLAKE(dev_priv) && port != PORT_A)
> + max = DPLL_ID_EHL_DPLL4;
> +
> ret = icl_calc_dpll_state(crtc_state, encoder);
> } else if (intel_port_is_tc(dev_priv, port)) {
> if (encoder->type == INTEL_OUTPUT_DP_MST) {
> @@ -2945,8 +2949,14 @@ static bool combo_pll_get_hw_state(struct
> drm_i915_private *dev_priv,
> struct intel_shared_dpll *pll,
> struct intel_dpll_hw_state
> *hw_state)
> {
> - return icl_pll_get_hw_state(dev_priv, pll, hw_state,
> - CNL_DPLL_ENABLE(pll->info->id));
> + i915_reg_t enable_reg = CNL_DPLL_ENABLE(pll->info->id);
> +
> + if (IS_ELKHARTLAKE(dev_priv) &&
> + pll->info->id == DPLL_ID_EHL_DPLL4) {
> + enable_reg = MG_PLL_ENABLE(0);
> + }
> +
> + return icl_pll_get_hw_state(dev_priv, pll, hw_state,
> enable_reg);
> }
>
> static bool tbt_pll_get_hw_state(struct drm_i915_private *dev_priv,
> @@ -3057,6 +3067,19 @@ static void combo_pll_enable(struct
> drm_i915_private *dev_priv,
> {
> i915_reg_t enable_reg = CNL_DPLL_ENABLE(pll->info->id);
>
> + if (IS_ELKHARTLAKE(dev_priv) &&
> + pll->info->id == DPLL_ID_EHL_DPLL4) {
> + enable_reg = MG_PLL_ENABLE(0);
> +
> + /*
> + * We need to disable DC states when this DPLL is
> enabled.
> + * This can be done by taking a reference on DPLL4
> power
> + * domain.
> + */
> + pll->wakeref = intel_display_power_get(dev_priv,
> + POWER_DOMAIN_DPL
> L_DC_OFF);
> + }
> +
> icl_pll_power_enable(dev_priv, pll, enable_reg);
>
> icl_dpll_write(dev_priv, pll);
> @@ -3152,7 +3175,19 @@ static void icl_pll_disable(struct
> drm_i915_private *dev_priv,
> static void combo_pll_disable(struct drm_i915_private *dev_priv,
> struct intel_shared_dpll *pll)
> {
> - icl_pll_disable(dev_priv, pll, CNL_DPLL_ENABLE(pll->info->id));
> + i915_reg_t enable_reg = CNL_DPLL_ENABLE(pll->info->id);
> +
> + if (IS_ELKHARTLAKE(dev_priv) &&
> + pll->info->id == DPLL_ID_EHL_DPLL4) {
> + enable_reg = MG_PLL_ENABLE(0);
> + icl_pll_disable(dev_priv, pll, enable_reg);
> +
> + intel_display_power_put(dev_priv,
> POWER_DOMAIN_DPLL_DC_OFF,
> + pll->wakeref);
> + return;
> + }
> +
> + icl_pll_disable(dev_priv, pll, enable_reg);
> }
>
> static void tbt_pll_disable(struct drm_i915_private *dev_priv,
> @@ -3230,6 +3265,7 @@ static const struct intel_dpll_mgr icl_pll_mgr
> = {
> static const struct dpll_info ehl_plls[] = {
> { "DPLL 0", &combo_pll_funcs, DPLL_ID_ICL_DPLL0, 0 },
> { "DPLL 1", &combo_pll_funcs, DPLL_ID_ICL_DPLL1, 0 },
> + { "DPLL 4", &combo_pll_funcs, DPLL_ID_EHL_DPLL4, 0 },
> { },
> };
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dpll_mgr.h
> b/drivers/gpu/drm/i915/display/intel_dpll_mgr.h
> index d0570414f3d1..3e2aa1099562 100644
> --- a/drivers/gpu/drm/i915/display/intel_dpll_mgr.h
> +++ b/drivers/gpu/drm/i915/display/intel_dpll_mgr.h
> @@ -28,6 +28,7 @@
> #include <linux/types.h>
>
> #include "intel_display.h"
> +#include "intel_wakeref.h"
>
> /*FIXME: Move this to a more appropriate place. */
> #define abs_diff(a, b) ({ \
> @@ -117,6 +118,10 @@ enum intel_dpll_id {
> * @DPLL_ID_ICL_DPLL1: ICL combo PHY DPLL1
> */
> DPLL_ID_ICL_DPLL1 = 1,
> + /**
> + * @DPLL_ID_EHL_DPLL4: EHL combo PHY DPLL4
> + */
> + DPLL_ID_EHL_DPLL4 = 2,
> /**
> * @DPLL_ID_ICL_TBTPLL: ICL TBT PLL
> */
> @@ -312,6 +317,7 @@ struct intel_shared_dpll {
> * @info: platform specific info
> */
> const struct dpll_info *info;
> + intel_wakeref_t wakeref;
> };
>
> #define SKL_DPLL0 0