[PATCH v4 30/49] drm/i915/bxt: add display initialize/uninitialize sequence (CDCLK)

Imre Deak
2015-04-15T13:43:01Z

From: Vandana Kannan <vandana.kannan@intel.com>

Add CDCLK specific display clock initialization sequence as per BSpec.

Note that the CDCLK initialization/uninitialization are done at their
current place only for simplicity, in a future patch - when more of the
runtime PM features will be enabled - these will be moved to power
well#1 and modeset encoder enabling/disabling hooks respectively. This
also means that atm dynamic power gating power well #1 is effectively
disabled.

The call to uninitialize CDCLK during system/runtime suspend will be
added later in this patchset.

v1: Added function definitions in header files
v2: Imre's review comments addressed
- Moved CDCLK related definitions to i915_reg.h
- Removed defintions for CDCLK frequency
- Split uninit_cdclk() by adding a phy_uninit function
- Calculate freq and decimal based on input frequency
- Program SSA precharge based on input frequency
- Use wait_for 1ms instead 200us udelay for DE PLL locking
- Removed initial value for divider, freq, decimal, ratio.
- Replaced polling loops with wait_for
- Parameterized latency optim setting
- Fix the parts where DE PLL has to be disabled.
- Call CDCLK selection from mode set

v3: (imre)
- add note about the plan to move the cdclk/phy init to a better place
- take rps.hw_lock around pcode access
- move DE PLL register macros here from another patch since they are
used here first
- add BXT_ prefix to CDCLK flags
- add missing masking when programming CDCLK_FREQ_DECIMAL

v4: (ville)
- split the CDCLK/PHY parts into two patches, update commit message
accordingly
- s/DISPLAY_PCU_CONTROL/HSW_PCODE_DE_WRITE_FREQ_REQ/
- simplify BXT_DE_PLL_RATIO macros
- fix BXT_DE_PLL_RATIO_MASK
- s/bxt_select_cdclk_freq/broxton_set_cdclk_freq/
- move cdclk init/uninit/set code from intel_ddi.c to intel_display.c
- remove redundant code comments for broxton_set_cdclk_freq()
- sanitize fixed point<->integer frequency value conversion
- use DRM_ERROR instead of WARN
- do RMW when programming BXT_DE_PLL_CTL for safety
- add note about PLL lock timeout being exactly 200us
- make PCU error messages more descriptive
- instead of using 0 freq to mean PLL off/bypass freq use 19200
for clarity, as the latter one is the actual rate
- simplify pcode programming, removing duplicated
sandybridge_pcode_write() call
- sanitize code flow, remove unnecessary scratch vars in
broxton_set_cdclk() (imre)
- Remove bound check for maxmimum freq to match current code.
This check will be added later at a more proper platform
independent place once atomic support lands.
- add note to remove freq guard band which isn't needed on BXT
- add note to reduce freq to minimum if no pipe is enabled
- combine broxton_modeset_global_pipes() with
valleyview_modeset_global_pipes()

Signed-off-by: Vandana Kannan <vandana.kannan@intel.com> (v2)
Signed-off-by: Imre Deak <imre.deak@intel.com>
---
drivers/gpu/drm/i915/i915_reg.h | 20 ++++
drivers/gpu/drm/i915/intel_ddi.c | 2 +
drivers/gpu/drm/i915/intel_display.c | 226 ++++++++++++++++++++++++++++++++++-
drivers/gpu/drm/i915/intel_drv.h | 3 +
4 files changed, 248 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 4b53b20..c79bf8d 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -5452,6 +5452,9 @@ enum skl_disp_power_wells {
#define DISP_FBC_WM_DIS (1<<15)
#define DISP_ARB_CTL2 0x45004
#define DISP_DATA_PARTITION_5_6 (1<<6)
+#define DBUF_CTL 0x45008
+#define DBUF_POWER_REQUEST (1<<31)
+#define DBUF_POWER_STATE (1<<30)
#define GEN7_MSG_CTL 0x45010
#define WAIT_FOR_PCH_RESET_ACK (1<<1)
#define WAIT_FOR_PCH_FLR_ACK (1<<0)
@@ -6403,6 +6406,7 @@ enum skl_disp_power_wells {
#define GEN6_PCODE_WRITE_D_COMP 0x11
#define GEN6_ENCODE_RC6_VID(mv) (((mv) - 245) / 5)
#define GEN6_DECODE_RC6_VID(vids) (((vids) * 5) + 245)
+#define HSW_PCODE_DE_WRITE_FREQ_REQ 0x17
#define DISPLAY_IPS_CONTROL 0x19
#define HSW_PCODE_DYNAMIC_DUTY_CYCLE_CONTROL 0x1A
#define GEN6_PCODE_DATA 0x138128
@@ -6874,6 +6878,13 @@ enum skl_disp_power_wells {
#define CDCLK_FREQ_675_617 (3<<26)
#define CDCLK_FREQ_DECIMAL_MASK (0x7ff)

+#define BXT_CDCLK_CD2X_DIV_SEL_MASK (3<<22)
+#define BXT_CDCLK_CD2X_DIV_SEL_1 (0<<22)
+#define BXT_CDCLK_CD2X_DIV_SEL_1_5 (1<<22)
+#define BXT_CDCLK_CD2X_DIV_SEL_2 (2<<22)
+#define BXT_CDCLK_CD2X_DIV_SEL_4 (3<<22)
+#define BXT_CDCLK_SSA_PRECHARGE_ENABLE (1<<16)
+
/* LCPLL_CTL */
#define LCPLL1_CTL 0x46010
#define LCPLL2_CTL 0x46014
@@ -6938,6 +6949,15 @@ enum skl_disp_power_wells {
#define GET_CFG_CR1_REG(id) (DPLL1_CFGCR1 + (id - SKL_DPLL1) * 8)
#define GET_CFG_CR2_REG(id) (DPLL1_CFGCR2 + (id - SKL_DPLL1) * 8)

+/* BXT display engine PLL */
+#define BXT_DE_PLL_CTL 0x6d000
+#define BXT_DE_PLL_RATIO(x) (x) /* {60,65,100} * 19.2MHz */
+#define BXT_DE_PLL_RATIO_MASK 0xff
+
+#define BXT_DE_PLL_ENABLE 0x46070
+#define BXT_DE_PLL_PLL_ENABLE (1 << 31)
+#define BXT_DE_PLL_LOCK (1 << 30)
+
/* Please see hsw_read_dcomp() and hsw_write_dcomp() before using this register,
* since on HSW we can't write to it using I915_WRITE. */
#define D_COMP_HSW (MCHBAR_MIRROR_BASE_SNB + 0x5F0C)
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index 5b50484..25d697b 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -1880,6 +1880,8 @@ void intel_ddi_pll_init(struct drm_device *dev)
if (IS_SKYLAKE(dev)) {
if (!(I915_READ(LCPLL1_CTL) & LCPLL_PLL_ENABLE))
DRM_ERROR("LCPLL1 is disabled\n");
+ } else if (IS_BROXTON(dev)) {
+ broxton_init_cdclk(dev);
} else {
/*
* The LCPLL register should be turned on by the BIOS. For now
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index bb5f2a5..5ee5d8c 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -5196,6 +5196,181 @@ static void modeset_update_crtc_power_domains(struct drm_atomic_state *state)
intel_display_set_init_power(dev_priv, false);
}

+void broxton_set_cdclk(struct drm_device *dev, int frequency)
+{
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ uint32_t divider;
+ uint32_t ratio;
+ uint32_t current_freq;
+ int ret;
+
+ /* frequency = 19.2MHz * ratio / 2 / div{1,1.5,2,4} */
+ switch (frequency) {
+ case 144000:
+ divider = BXT_CDCLK_CD2X_DIV_SEL_4;
+ ratio = BXT_DE_PLL_RATIO(60);
+ break;
+ case 288000:
+ divider = BXT_CDCLK_CD2X_DIV_SEL_2;
+ ratio = BXT_DE_PLL_RATIO(60);
+ break;
+ case 384000:
+ divider = BXT_CDCLK_CD2X_DIV_SEL_1_5;
+ ratio = BXT_DE_PLL_RATIO(60);
+ break;
+ case 576000:
+ divider = BXT_CDCLK_CD2X_DIV_SEL_1;
+ ratio = BXT_DE_PLL_RATIO(60);
+ break;
+ case 624000:
+ divider = BXT_CDCLK_CD2X_DIV_SEL_1;
+ ratio = BXT_DE_PLL_RATIO(65);
+ break;
+ case 19200:
+ /*
+ * Bypass frequency with DE PLL disabled. Init ratio, divider
+ * to suppress GCC warning.
+ */
+ ratio = 0;
+ divider = 0;
+ break;
+ default:
+ DRM_ERROR("unsupported CDCLK freq %d", frequency);
+
+ return;
+ }
+
+ mutex_lock(&dev_priv->rps.hw_lock);
+ /* Inform power controller of upcoming frequency change */
+ ret = sandybridge_pcode_write(dev_priv, HSW_PCODE_DE_WRITE_FREQ_REQ,
+ 0x80000000);
+ mutex_unlock(&dev_priv->rps.hw_lock);
+
+ if (ret) {
+ DRM_ERROR("PCode CDCLK freq change notify failed (err %d, freq %d)\n",
+ ret, frequency);
+ return;
+ }
+
+ current_freq = I915_READ(CDCLK_CTL) & CDCLK_FREQ_DECIMAL_MASK;
+ /* convert from .1 fixpoint MHz with -1MHz offset to kHz */
+ current_freq = current_freq * 500 + 1000;
+
+ /*
+ * DE PLL has to be disabled when
+ * - setting to 19.2MHz (bypass, PLL isn't used)
+ * - before setting to 624MHz (PLL needs toggling)
+ * - before setting to any frequency from 624MHz (PLL needs toggling)
+ */
+ if (frequency == 19200 || frequency == 624000 ||
+ current_freq == 624000) {
+ I915_WRITE(BXT_DE_PLL_ENABLE, ~BXT_DE_PLL_PLL_ENABLE);
+ /* Timeout 200us */
+ if (wait_for(!(I915_READ(BXT_DE_PLL_ENABLE) & BXT_DE_PLL_LOCK),
+ 1))
+ DRM_ERROR("timout waiting for DE PLL unlock\n");
+ }
+
+ if (frequency != 19200) {
+ uint32_t val;
+
+ val = I915_READ(BXT_DE_PLL_CTL);
+ val &= ~BXT_DE_PLL_RATIO_MASK;
+ val |= ratio;
+ I915_WRITE(BXT_DE_PLL_CTL, val);
+
+ I915_WRITE(BXT_DE_PLL_ENABLE, BXT_DE_PLL_PLL_ENABLE);
+ /* Timeout 200us */
+ if (wait_for(I915_READ(BXT_DE_PLL_ENABLE) & BXT_DE_PLL_LOCK, 1))
+ DRM_ERROR("timeout waiting for DE PLL lock\n");
+
+ val = I915_READ(CDCLK_CTL);
+ val &= ~BXT_CDCLK_CD2X_DIV_SEL_MASK;
+ val |= divider;
+ /*
+ * Disable SSA Precharge when CD clock frequency < 500 MHz,
+ * enable otherwise.
+ */
+ val &= ~BXT_CDCLK_SSA_PRECHARGE_ENABLE;
+ if (frequency >= 500000)
+ val |= BXT_CDCLK_SSA_PRECHARGE_ENABLE;
+
+ val &= ~CDCLK_FREQ_DECIMAL_MASK;
+ /* convert from kHz to .1 fixpoint MHz with -1MHz offset */
+ val |= (frequency - 1000) / 500;
+ I915_WRITE(CDCLK_CTL, val);
+ }
+
+ mutex_lock(&dev_priv->rps.hw_lock);
+ ret = sandybridge_pcode_write(dev_priv, HSW_PCODE_DE_WRITE_FREQ_REQ,
+ DIV_ROUND_UP(frequency, 25000));
+ mutex_unlock(&dev_priv->rps.hw_lock);
+
+ if (ret) {
+ DRM_ERROR("PCode CDCLK freq set failed, (err %d, freq %d)\n",
+ ret, frequency);
+ return;
+ }
+
+ dev_priv->cdclk_freq = frequency;
+}
+
+void broxton_init_cdclk(struct drm_device *dev)
+{
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ uint32_t val;
+
+ /*
+ * NDE_RSTWRN_OPT RST PCH Handshake En must always be 0b on BXT
+ * or else the reset will hang because there is no PCH to respond.
+ * Move the handshake programming to initialization sequence.
+ * Previously was left up to BIOS.
+ */
+ val = I915_READ(HSW_NDE_RSTWRN_OPT);
+ val &= ~RESET_PCH_HANDSHAKE_ENABLE;
+ I915_WRITE(HSW_NDE_RSTWRN_OPT, val);
+
+ /* Enable PG1 for cdclk */
+ intel_display_power_get(dev_priv, POWER_DOMAIN_PLLS);
+
+ /* check if cd clock is enabled */
+ if (I915_READ(BXT_DE_PLL_ENABLE) & BXT_DE_PLL_PLL_ENABLE) {
+ DRM_DEBUG_KMS("Display already initialized\n");
+ return;
+ }
+
+ /*
+ * FIXME:
+ * - The initial CDCLK needs to be read from VBT.
+ * Need to make this change after VBT has changes for BXT.
+ * - check if setting the max (or any) cdclk freq is really necessary
+ * here, it belongs to modeset time
+ */
+ broxton_set_cdclk(dev, 624000);
+
+ I915_WRITE(DBUF_CTL, I915_READ(DBUF_CTL) | DBUF_POWER_REQUEST);
+ udelay(10);
+
+ if (!(I915_READ(DBUF_CTL) & DBUF_POWER_STATE))
+ DRM_ERROR("DBuf power enable timeout!\n");
+}
+
+void broxton_uninit_cdclk(struct drm_device *dev)
+{
+ struct drm_i915_private *dev_priv = dev->dev_private;
+
+ I915_WRITE(DBUF_CTL, I915_READ(DBUF_CTL) & ~DBUF_POWER_REQUEST);
+ udelay(10);
+
+ if (I915_READ(DBUF_CTL) & DBUF_POWER_STATE)
+ DRM_ERROR("DBuf power disable timeout!\n");
+
+ /* Set minimum (bypass) frequency, in effect turning off the DE PLL */
+ broxton_set_cdclk(dev, 19200);
+
+ intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS);
+}
+
/* returns HPLL frequency in kHz */
static int valleyview_get_vco(struct drm_i915_private *dev_priv)
{
@@ -5363,6 +5538,26 @@ static int valleyview_calc_cdclk(struct drm_i915_private *dev_priv,
return 200000;
}

+static int broxton_calc_cdclk(struct drm_i915_private *dev_priv,
+ int max_pixclk)
+{
+ /*
+ * FIXME:
+ * - remove the guardband, it's not needed on BXT
+ * - set 19.2MHz bypass frequency if there are no active pipes
+ */
+ if (max_pixclk > 576000*9/10)
+ return 624000;
+ else if (max_pixclk > 384000*9/10)
+ return 576000;
+ else if (max_pixclk > 288000*9/10)
+ return 384000;
+ else if (max_pixclk > 144000*9/10)
+ return 288000;
+ else
+ return 144000;
+}
+
/* compute the max pixel clock for new configuration */
static int intel_mode_max_pixclk(struct drm_atomic_state *state)
{
@@ -5392,12 +5587,17 @@ static int valleyview_modeset_global_pipes(struct drm_atomic_state *state,
struct drm_i915_private *dev_priv = to_i915(state->dev);
struct intel_crtc *intel_crtc;
int max_pixclk = intel_mode_max_pixclk(state);
+ int cdclk;

if (max_pixclk < 0)
return max_pixclk;

- if (valleyview_calc_cdclk(dev_priv, max_pixclk) ==
- dev_priv->cdclk_freq)
+ if (IS_VALLEYVIEW(dev_priv))
+ cdclk = valleyview_calc_cdclk(dev_priv, max_pixclk);
+ else
+ cdclk = broxton_calc_cdclk(dev_priv, max_pixclk);
+
+ if (cdclk == dev_priv->cdclk_freq)
return 0;

/* disable/enable all currently active pipes while we change cdclk */
@@ -8827,6 +9027,23 @@ void hsw_disable_pc8(struct drm_i915_private *dev_priv)
intel_prepare_ddi(dev);
}

+static void broxton_modeset_global_resources(struct drm_atomic_state *state)
+{
+ struct drm_device *dev = state->dev;
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ int max_pixclk = intel_mode_max_pixclk(state);
+ int req_cdclk;
+
+ /* see the comment in valleyview_modeset_global_resources */
+ if (WARN_ON(max_pixclk < 0))
+ return;
+
+ req_cdclk = broxton_calc_cdclk(dev_priv, max_pixclk);
+
+ if (req_cdclk != dev_priv->cdclk_freq)
+ broxton_set_cdclk(dev, req_cdclk);
+}
+
static int haswell_crtc_compute_clock(struct intel_crtc *crtc,
struct intel_crtc_state *crtc_state)
{
@@ -11983,7 +12200,7 @@ static int __intel_set_mode(struct drm_crtc *crtc,
* mode set on this crtc. For other crtcs we need to use the
* adjusted_mode bits in the crtc directly.
*/
- if (IS_VALLEYVIEW(dev)) {
+ if (IS_VALLEYVIEW(dev) || IS_BROXTON(dev)) {
ret = valleyview_modeset_global_pipes(state, &prepare_pipes);
if (ret)
goto done;
@@ -14005,6 +14222,9 @@ static void intel_init_display(struct drm_device *dev)
} else if (IS_VALLEYVIEW(dev)) {
dev_priv->display.modeset_global_resources =
valleyview_modeset_global_resources;
+ } else if (IS_BROXTON(dev)) {
+ dev_priv->display.modeset_global_resources =
+ broxton_modeset_global_resources;
}

switch (INTEL_INFO(dev)->gen) {
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 6a2ee0c..5ba88eb 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1112,6 +1112,9 @@ void intel_prepare_reset(struct drm_device *dev);
void intel_finish_reset(struct drm_device *dev);
void hsw_enable_pc8(struct drm_i915_private *dev_priv);
void hsw_disable_pc8(struct drm_i915_private *dev_priv);
+void broxton_init_cdclk(struct drm_device *dev);
+void broxton_uninit_cdclk(struct drm_device *dev);
+void broxton_set_cdclk(struct drm_device *dev, int frequency);
void intel_dp_get_m_n(struct intel_crtc *crtc,
struct intel_crtc_state *pipe_config);
void intel_dp_set_m_n(struct intel_crtc *crtc, enum link_m_n_set m_n);
--
2.1.0