Commit 5d96d8af authored by Damien Lespiau's avatar Damien Lespiau Committed by Daniel Vetter

drm/i915/skl: Deinit/init the display at suspend/resume

We need to re-init the display hardware when going out of suspend. This
includes:

  - Hooking the PCH to the reset logic
  - Restoring CDCDLK
  - Enabling the DDB power

Among those, only the CDCDLK one is a bit tricky. There's some
complexity in that:

  - DPLL0 (which is the source for CDCLK) has two VCOs, each with a set
    of supported frequencies. As eDP also uses DPLL0 for its link rate,
    once DPLL0 is on, we restrict the possible eDP link rates the chosen
    VCO.
  - CDCLK also limits the bandwidth available to push pixels.

So, as a first step, this commit restore what the BIOS set, until I can
do more testing.

In case that's of interest for the reviewer, I've unit tested the
function that derives the decimal frequency field:

  #include <stdio.h>
  #include <stdint.h>
  #include <assert.h>

  #define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x)))

  static const struct dpll_freq {
          unsigned int freq;
          unsigned int decimal;
  } freqs[] = {
          { .freq = 308570, .decimal = 0b01001100111},
          { .freq = 337500, .decimal = 0b01010100001},
          { .freq = 432000, .decimal = 0b01101011110},
          { .freq = 450000, .decimal = 0b01110000010},
          { .freq = 540000, .decimal = 0b10000110110},
          { .freq = 617140, .decimal = 0b10011010000},
          { .freq = 675000, .decimal = 0b10101000100},
  };

  static void intbits(unsigned int v)
  {
          int i;

          for(i = 10; i >= 0; i--)
                  putchar('0' + ((v >> i) & 1));
  }

  static unsigned int freq_decimal(unsigned int freq /* in kHz */)
  {
          return (freq - 1000) / 500;
  }

  static void test_freq(const struct dpll_freq *entry)
  {
          unsigned int decimal = freq_decimal(entry->freq);

          printf("freq: %d, expected: ", entry->freq);
          intbits(entry->decimal);
          printf(", got: ");
          intbits(decimal);
          putchar('\n');

          assert(decimal == entry->decimal);
  }

  int main(int argc, char **argv)
  {
          int i;

          for (i = 0; i < ARRAY_SIZE(freqs); i++)
                  test_freq(&freqs[i]);

          return 0;
  }

v2:
  - Rebase on top of -nightly
  - Use (freq - 1000) / 500 for the decimal frequency (Ville)
  - Fix setting the enable bit of HSW_NDE_RSTWRN_OPT (Ville)
  - Rename skl_display_{resume,suspend} to skl_{init,uninit}_cdclk to
    be consistent with the BXT code (Ville)
  - Store boot CDCLK in ddi_pll_init (Ville)
  - Merge dev_priv's skl_boot_cdclk into cdclk_freq
  - Use LCPLL_PLL_LOCK instead of (1 << 30) (Ville)
  - Replace various '0' by SKL_DPLL0 to be a bit more explicit that
    we're programming DPLL0
  - Busy poll the PCU before doing the frequency change. It takes about
    3/4 cycles, each separated by 10us, to get the ACK from the CPU
    (Ville)

v3:
  - Restore dev_priv->skl_boot_cdclk, leaving unification with
    dev_priv->cdclk_freq for a later patch (Daniel, Ville)
Reviewed-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: default avatarDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
parent e61b9958
......@@ -1047,6 +1047,8 @@ static int skl_suspend_complete(struct drm_i915_private *dev_priv)
*/
intel_csr_load_status_set(dev_priv, FW_UNINITIALIZED);
skl_uninit_cdclk(dev_priv);
return 0;
}
......@@ -1093,6 +1095,7 @@ static int skl_resume_prepare(struct drm_i915_private *dev_priv)
{
struct drm_device *dev = dev_priv->dev;
skl_init_cdclk(dev_priv);
intel_csr_load_program(dev);
return 0;
......
......@@ -1705,6 +1705,7 @@ struct drm_i915_private {
int num_fence_regs; /* 8 on pre-965, 16 otherwise */
unsigned int fsb_freq, mem_freq, is_ddr3;
unsigned int skl_boot_cdclk;
unsigned int cdclk_freq;
unsigned int hpll_freq;
......
......@@ -6699,6 +6699,9 @@ enum skl_disp_power_wells {
#define GEN9_MEM_LATENCY_LEVEL_1_5_SHIFT 8
#define GEN9_MEM_LATENCY_LEVEL_2_6_SHIFT 16
#define GEN9_MEM_LATENCY_LEVEL_3_7_SHIFT 24
#define SKL_PCODE_CDCLK_CONTROL 0x7
#define SKL_CDCLK_PREPARE_FOR_CHANGE 0x3
#define SKL_CDCLK_READY_FOR_CHANGE 0x1
#define GEN6_PCODE_WRITE_MIN_FREQ_TABLE 0x8
#define GEN6_PCODE_READ_MIN_FREQ_TABLE 0x9
#define GEN6_READ_OC_PARAMS 0xc
......
......@@ -2510,6 +2510,7 @@ void intel_ddi_pll_init(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = dev->dev_private;
uint32_t val = I915_READ(LCPLL_CTL);
int cdclk_freq;
if (IS_SKYLAKE(dev))
skl_shared_dplls_init(dev_priv);
......@@ -2518,12 +2519,15 @@ void intel_ddi_pll_init(struct drm_device *dev)
else
hsw_shared_dplls_init(dev_priv);
DRM_DEBUG_KMS("CDCLK running at %dKHz\n",
dev_priv->display.get_display_clock_speed(dev));
cdclk_freq = dev_priv->display.get_display_clock_speed(dev);
DRM_DEBUG_KMS("CDCLK running at %dKHz\n", cdclk_freq);
if (IS_SKYLAKE(dev)) {
dev_priv->skl_boot_cdclk = cdclk_freq;
if (!(I915_READ(LCPLL1_CTL) & LCPLL_PLL_ENABLE))
DRM_ERROR("LCPLL1 is disabled\n");
else
intel_display_power_get(dev_priv, POWER_DOMAIN_PLLS);
} else if (IS_BROXTON(dev)) {
broxton_init_cdclk(dev);
broxton_ddi_phy_init(dev);
......
......@@ -5527,6 +5527,214 @@ void broxton_uninit_cdclk(struct drm_device *dev)
intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS);
}
static const struct skl_cdclk_entry {
unsigned int freq;
unsigned int vco;
} skl_cdclk_frequencies[] = {
{ .freq = 308570, .vco = 8640 },
{ .freq = 337500, .vco = 8100 },
{ .freq = 432000, .vco = 8640 },
{ .freq = 450000, .vco = 8100 },
{ .freq = 540000, .vco = 8100 },
{ .freq = 617140, .vco = 8640 },
{ .freq = 675000, .vco = 8100 },
};
static unsigned int skl_cdclk_decimal(unsigned int freq)
{
return (freq - 1000) / 500;
}
static unsigned int skl_cdclk_get_vco(unsigned int freq)
{
unsigned int i;
for (i = 0; i < ARRAY_SIZE(skl_cdclk_frequencies); i++) {
const struct skl_cdclk_entry *e = &skl_cdclk_frequencies[i];
if (e->freq == freq)
return e->vco;
}
return 8100;
}
static void
skl_dpll0_enable(struct drm_i915_private *dev_priv, unsigned int required_vco)
{
unsigned int min_freq;
u32 val;
/* select the minimum CDCLK before enabling DPLL 0 */
val = I915_READ(CDCLK_CTL);
val &= ~CDCLK_FREQ_SEL_MASK | ~CDCLK_FREQ_DECIMAL_MASK;
val |= CDCLK_FREQ_337_308;
if (required_vco == 8640)
min_freq = 308570;
else
min_freq = 337500;
val = CDCLK_FREQ_337_308 | skl_cdclk_decimal(min_freq);
I915_WRITE(CDCLK_CTL, val);
POSTING_READ(CDCLK_CTL);
/*
* We always enable DPLL0 with the lowest link rate possible, but still
* taking into account the VCO required to operate the eDP panel at the
* desired frequency. The usual DP link rates operate with a VCO of
* 8100 while the eDP 1.4 alternate link rates need a VCO of 8640.
* The modeset code is responsible for the selection of the exact link
* rate later on, with the constraint of choosing a frequency that
* works with required_vco.
*/
val = I915_READ(DPLL_CTRL1);
val &= ~(DPLL_CTRL1_HDMI_MODE(SKL_DPLL0) | DPLL_CTRL1_SSC(SKL_DPLL0) |
DPLL_CTRL1_LINK_RATE_MASK(SKL_DPLL0));
val |= DPLL_CTRL1_OVERRIDE(SKL_DPLL0);
if (required_vco == 8640)
val |= DPLL_CTRL1_LINK_RATE(DPLL_CTRL1_LINK_RATE_1080,
SKL_DPLL0);
else
val |= DPLL_CTRL1_LINK_RATE(DPLL_CTRL1_LINK_RATE_810,
SKL_DPLL0);
I915_WRITE(DPLL_CTRL1, val);
POSTING_READ(DPLL_CTRL1);
I915_WRITE(LCPLL1_CTL, I915_READ(LCPLL1_CTL) | LCPLL_PLL_ENABLE);
if (wait_for(I915_READ(LCPLL1_CTL) & LCPLL_PLL_LOCK, 5))
DRM_ERROR("DPLL0 not locked\n");
}
static bool skl_cdclk_pcu_ready(struct drm_i915_private *dev_priv)
{
int ret;
u32 val;
/* inform PCU we want to change CDCLK */
val = SKL_CDCLK_PREPARE_FOR_CHANGE;
mutex_lock(&dev_priv->rps.hw_lock);
ret = sandybridge_pcode_read(dev_priv, SKL_PCODE_CDCLK_CONTROL, &val);
mutex_unlock(&dev_priv->rps.hw_lock);
return ret == 0 && (val & SKL_CDCLK_READY_FOR_CHANGE);
}
static bool skl_cdclk_wait_for_pcu_ready(struct drm_i915_private *dev_priv)
{
unsigned int i;
for (i = 0; i < 15; i++) {
if (skl_cdclk_pcu_ready(dev_priv))
return true;
udelay(10);
}
return false;
}
static void skl_set_cdclk(struct drm_i915_private *dev_priv, unsigned int freq)
{
u32 freq_select, pcu_ack;
DRM_DEBUG_DRIVER("Changing CDCLK to %dKHz\n", freq);
if (!skl_cdclk_wait_for_pcu_ready(dev_priv)) {
DRM_ERROR("failed to inform PCU about cdclk change\n");
return;
}
/* set CDCLK_CTL */
switch(freq) {
case 450000:
case 432000:
freq_select = CDCLK_FREQ_450_432;
pcu_ack = 1;
break;
case 540000:
freq_select = CDCLK_FREQ_540;
pcu_ack = 2;
break;
case 308570:
case 337500:
default:
freq_select = CDCLK_FREQ_337_308;
pcu_ack = 0;
break;
case 617140:
case 675000:
freq_select = CDCLK_FREQ_675_617;
pcu_ack = 3;
break;
}
I915_WRITE(CDCLK_CTL, freq_select | skl_cdclk_decimal(freq));
POSTING_READ(CDCLK_CTL);
/* inform PCU of the change */
mutex_lock(&dev_priv->rps.hw_lock);
sandybridge_pcode_write(dev_priv, SKL_PCODE_CDCLK_CONTROL, pcu_ack);
mutex_unlock(&dev_priv->rps.hw_lock);
}
void skl_uninit_cdclk(struct drm_i915_private *dev_priv)
{
/* disable DBUF power */
I915_WRITE(DBUF_CTL, I915_READ(DBUF_CTL) & ~DBUF_POWER_REQUEST);
POSTING_READ(DBUF_CTL);
udelay(10);
if (I915_READ(DBUF_CTL) & DBUF_POWER_STATE)
DRM_ERROR("DBuf power disable timeout\n");
/* disable DPLL0 */
I915_WRITE(LCPLL1_CTL, I915_READ(LCPLL1_CTL) & ~LCPLL_PLL_ENABLE);
if (wait_for(!(I915_READ(LCPLL1_CTL) & LCPLL_PLL_LOCK), 1))
DRM_ERROR("Couldn't disable DPLL0\n");
intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS);
}
void skl_init_cdclk(struct drm_i915_private *dev_priv)
{
u32 val;
unsigned int required_vco;
/* enable PCH reset handshake */
val = I915_READ(HSW_NDE_RSTWRN_OPT);
I915_WRITE(HSW_NDE_RSTWRN_OPT, val | RESET_PCH_HANDSHAKE_ENABLE);
/* enable PG1 and Misc I/O */
intel_display_power_get(dev_priv, POWER_DOMAIN_PLLS);
/* DPLL0 already enabed !? */
if (I915_READ(LCPLL1_CTL) & LCPLL_PLL_ENABLE) {
DRM_DEBUG_DRIVER("DPLL0 already running\n");
return;
}
/* enable DPLL0 */
required_vco = skl_cdclk_get_vco(dev_priv->skl_boot_cdclk);
skl_dpll0_enable(dev_priv, required_vco);
/* set CDCLK to the frequency the BIOS chose */
skl_set_cdclk(dev_priv, dev_priv->skl_boot_cdclk);
/* enable DBUF power */
I915_WRITE(DBUF_CTL, I915_READ(DBUF_CTL) | DBUF_POWER_REQUEST);
POSTING_READ(DBUF_CTL);
udelay(10);
if (!(I915_READ(DBUF_CTL) & DBUF_POWER_STATE))
DRM_ERROR("DBuf power enable timeout\n");
}
/* returns HPLL frequency in kHz */
static int valleyview_get_vco(struct drm_i915_private *dev_priv)
{
......
......@@ -1118,6 +1118,8 @@ void broxton_ddi_phy_init(struct drm_device *dev);
void broxton_ddi_phy_uninit(struct drm_device *dev);
void bxt_enable_dc9(struct drm_i915_private *dev_priv);
void bxt_disable_dc9(struct drm_i915_private *dev_priv);
void skl_init_cdclk(struct drm_i915_private *dev_priv);
void skl_uninit_cdclk(struct drm_i915_private *dev_priv);
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);
......
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