[PATCH 66/89] drm/i915/skl: Implementation of SKL DPLL programming

Damien Lespiau
2014-09-04T11:29:01Z

From: Satheeshakrishna M <satheeshakrishna.m@intel.com>

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)

Signed-off-by: Satheeshakrishna M <satheeshakrishna.m@intel.com> (v3)
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
---
drivers/gpu/drm/i915/intel_ddi.c | 225 ++++++++++++++++++++++++++++++++++++++-
1 file changed, 224 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index 439cd50..f68e04c 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -915,6 +915,225 @@ 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 (!((P2[k] != 2 && 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->config.dpll_hw_state.ctrl1 = ctrl1;
+ intel_crtc->config.dpll_hw_state.cfgcr1 = cfgcr1;
+ intel_crtc->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->config.ddi_pll_sel = pll->id + 1;
+
+ return true;
+}

/*
* Tries to find a *shared* PLL for the CRTC and store it in
@@ -926,12 +1145,16 @@ hsw_ddi_pll_select(struct intel_crtc *intel_crtc,
bool intel_ddi_pll_select(struct intel_crtc *intel_crtc)
{
struct drm_crtc *crtc = &intel_crtc->base;
+ struct drm_device *dev = crtc->dev;
struct intel_encoder *intel_encoder = intel_ddi_get_crtc_encoder(crtc);
int clock = intel_crtc->config.port_clock;

intel_put_shared_dpll(intel_crtc);

- 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)
--
1.8.3.1