[PATCH] drm/i915/ehl: Add support for DPLL4 (v6)

Vivek Kasireddy
2019-06-06T00:24:24Z

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

Cc: Lucas De Marchi <lucas.demarchi@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>
Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
---
drivers/gpu/drm/i915/intel_display_power.c | 20 +++++++++++
drivers/gpu/drm/i915/intel_display_power.h | 6 ++++
drivers/gpu/drm/i915/intel_dpll_mgr.c | 40 +++++++++++++++++++---
drivers/gpu/drm/i915/intel_dpll_mgr.h | 5 +++
4 files changed, 67 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display_power.c b/drivers/gpu/drm/i915/intel_display_power.c
index 278a7edc94f5..fd6d0d6a285a 100644
--- a/drivers/gpu/drm/i915/intel_display_power.c
+++ b/drivers/gpu/drm/i915/intel_display_power.c
@@ -4524,6 +4524,26 @@ void intel_power_domains_resume(struct drm_i915_private *i915)
intel_power_domains_verify_state(i915);
}

+void icl_disable_dc_states(struct drm_i915_private *dev_priv,
+ struct intel_shared_dpll *pll)
+{
+ enum intel_display_power_domain domain;
+
+ for_each_power_domain(domain, ICL_DISPLAY_DC_OFF_POWER_DOMAINS)
+ pll->wakerefs[domain] = intel_display_power_get(dev_priv,
+ domain);
+}
+
+void icl_enable_dc_states(struct drm_i915_private *dev_priv,
+ struct intel_shared_dpll *pll)
+{
+ enum intel_display_power_domain domain;
+
+ for_each_power_domain(domain, ICL_DISPLAY_DC_OFF_POWER_DOMAINS)
+ intel_display_power_put(dev_priv, domain,
+ pll->wakerefs[domain]);
+}
+
#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)

static void intel_power_domains_dump_info(struct drm_i915_private *i915)
diff --git a/drivers/gpu/drm/i915/intel_display_power.h b/drivers/gpu/drm/i915/intel_display_power.h
index ff57b0a7fe59..2abaa3806ec6 100644
--- a/drivers/gpu/drm/i915/intel_display_power.h
+++ b/drivers/gpu/drm/i915/intel_display_power.h
@@ -12,6 +12,7 @@

struct drm_i915_private;
struct intel_encoder;
+struct intel_shared_dpll;

enum intel_display_power_domain {
POWER_DOMAIN_DISPLAY_CORE,
@@ -285,4 +286,9 @@ void chv_phy_powergate_lanes(struct intel_encoder *encoder,
bool chv_phy_powergate_ch(struct drm_i915_private *dev_priv, enum dpio_phy phy,
enum dpio_channel ch, bool override);

+void icl_disable_dc_states(struct drm_i915_private *dev_priv,
+ struct intel_shared_dpll *pll);
+void icl_enable_dc_states(struct drm_i915_private *dev_priv,
+ struct intel_shared_dpll *pll);
+
#endif /* __INTEL_DISPLAY_POWER_H__ */
diff --git a/drivers/gpu/drm/i915/intel_dpll_mgr.c b/drivers/gpu/drm/i915/intel_dpll_mgr.c
index 69787f259677..2829b37e2909 100644
--- a/drivers/gpu/drm/i915/intel_dpll_mgr.c
+++ b/drivers/gpu/drm/i915/intel_dpll_mgr.c
@@ -22,8 +22,8 @@
*/

#include "intel_dpio_phy.h"
-#include "intel_dpll_mgr.h"
#include "intel_drv.h"
+#include "intel_dpll_mgr.h"

/**
* DOC: Display PLLs
@@ -2806,6 +2806,12 @@ 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)) {
+ if (encoder->type != INTEL_OUTPUT_EDP)
+ 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 +2951,14 @@ 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 +3069,14 @@ 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);
+
+ /* Need to disable DC states when this DPLL is enabled. */
+ icl_disable_dc_states(dev_priv, pll);
+ }
+
icl_pll_power_enable(dev_priv, pll, enable_reg);

icl_dpll_write(dev_priv, pll);
@@ -3152,7 +3172,18 @@ 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);
+
+ icl_enable_dc_states(dev_priv, pll);
+ return;
+ }
+
+ icl_pll_disable(dev_priv, pll, enable_reg);
}

static void tbt_pll_disable(struct drm_i915_private *dev_priv,
@@ -3230,6 +3261,7 @@ 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/intel_dpll_mgr.h b/drivers/gpu/drm/i915/intel_dpll_mgr.h
index b5dd9c7ad772..cf05e53b3a12 100644
--- a/drivers/gpu/drm/i915/intel_dpll_mgr.h
+++ b/drivers/gpu/drm/i915/intel_dpll_mgr.h
@@ -117,6 +117,10 @@ 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 +316,7 @@ struct intel_shared_dpll {
* @info: platform specific info
*/
const struct dpll_info *info;
+ intel_wakeref_t wakerefs[POWER_DOMAIN_NUM];
};

#define SKL_DPLL0 0
--
2.21.0