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

Vivek Kasireddy
2019-06-22T02:01:19Z

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

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_DOMAIN_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_DPLL_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
--
2.21.0