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

Ville Syrjälä
2015-04-15T14:14:05Z

On Wed, Apr 15, 2015 at 04:42:56PM +0300, Imre Deak wrote:
> 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>

That's quite a changelog I caused. Sorry :)

But I like how it's looking now. A few minor FIXMEs in there, but I
agree that those can be dealt with later.

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.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

--
Ville Syrjälä
Intel OTC