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drm/i915/skl: Implementation of SKL DPLL programming
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This patch implements SKL DPLL programming that includes:
        - DPLL allocation
        - wide range PLL calculation and programming
        - DP link rate programming
        - DDI to DPLL mapping

v2: Incorporated following changes
        - Added vfunc for function required outside
        - Fixed multiple comments in WRPLL calculation

v3: - Fix the DCO computation
    - Move the initialization up to not clobber the computed values
    - Use the correct macro for DP link rate programming.
    - Use wait_for() to wait for the PLL locked bit

v4: Rebase on top of nigthly (Damien)

v5: A few code cleanups in the WRPLL computation (Damien)
    - Use uint32_t when possible
    - Use abs_diff() in the WRPLL computation
    - Make the 64bits divisions use div64_u64()
    - Fix typo in dco_central_feq_deviation (freq)
    - Replace the chain of breaks with a goto

v6: Port of the patch to work on top of the shared DPLLs (Damien)
v7: Don't try to handle eDP in ddi_pll_select() (Damien)
v8: Modified as per review comments from Paulo (Satheesh)
v9: Rebase on top of Ander's clock computation staging work for atomic (Damien)

Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Satheeshakrishna M <satheeshakrishna.m@intel.com> (v3)
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
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@danvet
Satheeshakrishna M authored and danvet committed Nov 14, 2014
1 parent efa80ad commit 82d3543
Showing 1 changed file with 225 additions and 1 deletion.
226 changes: 225 additions & 1 deletion drivers/gpu/drm/i915/intel_ddi.c
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Original file line number Diff line number Diff line change
Expand Up @@ -937,6 +937,226 @@ hsw_ddi_pll_select(struct intel_crtc *intel_crtc,
return true;
}

struct skl_wrpll_params {
uint32_t dco_fraction;
uint32_t dco_integer;
uint32_t qdiv_ratio;
uint32_t qdiv_mode;
uint32_t kdiv;
uint32_t pdiv;
uint32_t central_freq;
};

static void
skl_ddi_calculate_wrpll(int clock /* in Hz */,
struct skl_wrpll_params *wrpll_params)
{
uint64_t afe_clock = clock * 5; /* AFE Clock is 5x Pixel clock */
uint64_t dco_central_freq[3] = {8400000000, 9000000000, 9600000000};
uint32_t min_dco_deviation = 400;
uint32_t min_dco_index = 3;
uint32_t P0[4] = {1, 2, 3, 7};
uint32_t P2[4] = {1, 2, 3, 5};
bool found = false;
uint32_t candidate_p = 0;
uint32_t candidate_p0[3] = {0}, candidate_p1[3] = {0};
uint32_t candidate_p2[3] = {0};
uint32_t dco_central_freq_deviation[3];
uint32_t i, P1, k, dco_count;
bool retry_with_odd = false;
uint64_t dco_freq;

/* Determine P0, P1 or P2 */
for (dco_count = 0; dco_count < 3; dco_count++) {
found = false;
candidate_p =
div64_u64(dco_central_freq[dco_count], afe_clock);
if (retry_with_odd == false)
candidate_p = (candidate_p % 2 == 0 ?
candidate_p : candidate_p + 1);

for (P1 = 1; P1 < candidate_p; P1++) {
for (i = 0; i < 4; i++) {
if (!(P0[i] != 1 || P1 == 1))
continue;

for (k = 0; k < 4; k++) {
if (P1 != 1 && P2[k] != 2)
continue;

if (candidate_p == P0[i] * P1 * P2[k]) {
/* Found possible P0, P1, P2 */
found = true;
candidate_p0[dco_count] = P0[i];
candidate_p1[dco_count] = P1;
candidate_p2[dco_count] = P2[k];
goto found;
}

}
}
}

found:
if (found) {
dco_central_freq_deviation[dco_count] =
div64_u64(10000 *
abs_diff((candidate_p * afe_clock),
dco_central_freq[dco_count]),
dco_central_freq[dco_count]);

if (dco_central_freq_deviation[dco_count] <
min_dco_deviation) {
min_dco_deviation =
dco_central_freq_deviation[dco_count];
min_dco_index = dco_count;
}
}

if (min_dco_index > 2 && dco_count == 2) {
retry_with_odd = true;
dco_count = 0;
}
}

if (min_dco_index > 2) {
WARN(1, "No valid values found for the given pixel clock\n");
} else {
wrpll_params->central_freq = dco_central_freq[min_dco_index];

switch (dco_central_freq[min_dco_index]) {
case 9600000000:
wrpll_params->central_freq = 0;
break;
case 9000000000:
wrpll_params->central_freq = 1;
break;
case 8400000000:
wrpll_params->central_freq = 3;
}

switch (candidate_p0[min_dco_index]) {
case 1:
wrpll_params->pdiv = 0;
break;
case 2:
wrpll_params->pdiv = 1;
break;
case 3:
wrpll_params->pdiv = 2;
break;
case 7:
wrpll_params->pdiv = 4;
break;
default:
WARN(1, "Incorrect PDiv\n");
}

switch (candidate_p2[min_dco_index]) {
case 5:
wrpll_params->kdiv = 0;
break;
case 2:
wrpll_params->kdiv = 1;
break;
case 3:
wrpll_params->kdiv = 2;
break;
case 1:
wrpll_params->kdiv = 3;
break;
default:
WARN(1, "Incorrect KDiv\n");
}

wrpll_params->qdiv_ratio = candidate_p1[min_dco_index];
wrpll_params->qdiv_mode =
(wrpll_params->qdiv_ratio == 1) ? 0 : 1;

dco_freq = candidate_p0[min_dco_index] *
candidate_p1[min_dco_index] *
candidate_p2[min_dco_index] * afe_clock;

/*
* Intermediate values are in Hz.
* Divide by MHz to match bsepc
*/
wrpll_params->dco_integer = div_u64(dco_freq, (24 * MHz(1)));
wrpll_params->dco_fraction =
div_u64(((div_u64(dco_freq, 24) -
wrpll_params->dco_integer * MHz(1)) * 0x8000), MHz(1));

}
}


static bool
skl_ddi_pll_select(struct intel_crtc *intel_crtc,
struct intel_encoder *intel_encoder,
int clock)
{
struct intel_shared_dpll *pll;
uint32_t ctrl1, cfgcr1, cfgcr2;

/*
* See comment in intel_dpll_hw_state to understand why we always use 0
* as the DPLL id in this function.
*/

ctrl1 = DPLL_CTRL1_OVERRIDE(0);

if (intel_encoder->type == INTEL_OUTPUT_HDMI) {
struct skl_wrpll_params wrpll_params = { 0, };

ctrl1 |= DPLL_CTRL1_HDMI_MODE(0);

skl_ddi_calculate_wrpll(clock * 1000, &wrpll_params);

cfgcr1 = DPLL_CFGCR1_FREQ_ENABLE |
DPLL_CFGCR1_DCO_FRACTION(wrpll_params.dco_fraction) |
wrpll_params.dco_integer;

cfgcr2 = DPLL_CFGCR2_QDIV_RATIO(wrpll_params.qdiv_ratio) |
DPLL_CFGCR2_QDIV_MODE(wrpll_params.qdiv_mode) |
DPLL_CFGCR2_KDIV(wrpll_params.kdiv) |
DPLL_CFGCR2_PDIV(wrpll_params.pdiv) |
wrpll_params.central_freq;
} else if (intel_encoder->type == INTEL_OUTPUT_DISPLAYPORT) {
struct drm_encoder *encoder = &intel_encoder->base;
struct intel_dp *intel_dp = enc_to_intel_dp(encoder);

switch (intel_dp->link_bw) {
case DP_LINK_BW_1_62:
ctrl1 |= DPLL_CRTL1_LINK_RATE(DPLL_CRTL1_LINK_RATE_810, 0);
break;
case DP_LINK_BW_2_7:
ctrl1 |= DPLL_CRTL1_LINK_RATE(DPLL_CRTL1_LINK_RATE_1350, 0);
break;
case DP_LINK_BW_5_4:
ctrl1 |= DPLL_CRTL1_LINK_RATE(DPLL_CRTL1_LINK_RATE_2700, 0);
break;
}

cfgcr1 = cfgcr2 = 0;
} else /* eDP */
return true;

intel_crtc->new_config->dpll_hw_state.ctrl1 = ctrl1;
intel_crtc->new_config->dpll_hw_state.cfgcr1 = cfgcr1;
intel_crtc->new_config->dpll_hw_state.cfgcr2 = cfgcr2;

pll = intel_get_shared_dpll(intel_crtc);
if (pll == NULL) {
DRM_DEBUG_DRIVER("failed to find PLL for pipe %c\n",
pipe_name(intel_crtc->pipe));
return false;
}

/* shared DPLL id 0 is DPLL 1 */
intel_crtc->new_config->ddi_pll_sel = pll->id + 1;

return true;
}

/*
* Tries to find a *shared* PLL for the CRTC and store it in
Expand All @@ -947,11 +1167,15 @@ hsw_ddi_pll_select(struct intel_crtc *intel_crtc,
*/
bool intel_ddi_pll_select(struct intel_crtc *intel_crtc)
{
struct drm_device *dev = intel_crtc->base.dev;
struct intel_encoder *intel_encoder =
intel_ddi_get_crtc_new_encoder(intel_crtc);
int clock = intel_crtc->new_config->port_clock;

return hsw_ddi_pll_select(intel_crtc, intel_encoder, clock);
if (IS_SKYLAKE(dev))
return skl_ddi_pll_select(intel_crtc, intel_encoder, clock);
else
return hsw_ddi_pll_select(intel_crtc, intel_encoder, clock);
}

void intel_ddi_set_pipe_settings(struct drm_crtc *crtc)
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