Message ID | e3ea1e222fee3f721db50d2e6e7a4e76ada6610c.1431440230.git.jani.nikula@intel.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
On Tue, May 12, 2015 at 05:20:39PM +0300, Jani Nikula wrote: > Currently DSI PLL N1 is hardcoded off. Make it possible to use it > later. This should have no functional changes for now. > > Signed-off-by: Jani Nikula <jani.nikula@intel.com> > --- > drivers/gpu/drm/i915/intel_dsi_pll.c | 17 +++++++++++------ > 1 file changed, 11 insertions(+), 6 deletions(-) > > diff --git a/drivers/gpu/drm/i915/intel_dsi_pll.c b/drivers/gpu/drm/i915/intel_dsi_pll.c > index 9ada06ec88e5..effb561e00a0 100644 > --- a/drivers/gpu/drm/i915/intel_dsi_pll.c > +++ b/drivers/gpu/drm/i915/intel_dsi_pll.c > @@ -160,7 +160,7 @@ static u32 dsi_clk_from_pclk(u32 pclk, int pixel_format, int lane_count) > static int dsi_calc_mnp(int target_dsi_clk, struct dsi_mnp *dsi_mnp) > { > unsigned int calc_m = 0, calc_p = 0; > - unsigned int m, n, p; > + unsigned int m, n = 1, p; > int ref_clk = 25000; > int delta = target_dsi_clk; > u32 m_seed; > @@ -177,7 +177,7 @@ static int dsi_calc_mnp(int target_dsi_clk, struct dsi_mnp *dsi_mnp) > * Find the optimal m and p divisors with minimal delta > * +/- the required clock > */ > - int calc_dsi_clk = (m * ref_clk) / p; > + int calc_dsi_clk = (m * ref_clk) / (p * n); > int d = abs(target_dsi_clk - calc_dsi_clk); > if (d < delta) { > delta = d; > @@ -187,10 +187,11 @@ static int dsi_calc_mnp(int target_dsi_clk, struct dsi_mnp *dsi_mnp) > } > } > > + /* register has log2(N1), this works fine for powers of two */ > + n = ffz(~(n)); I think 'ffs() - 1' is what's been used elsewhere for this. Although in this case we could avoid it entirely by keeping n as the log2 value always. Either way would be fine by me. > m_seed = lfsr_converts[calc_m - 62]; > - n = 1; > dsi_mnp->dsi_pll_ctrl = 1 << (DSI_PLL_P1_POST_DIV_SHIFT + calc_p - 2); > - dsi_mnp->dsi_pll_div = (n - 1) << DSI_PLL_N1_DIV_SHIFT | > + dsi_mnp->dsi_pll_div = n << DSI_PLL_N1_DIV_SHIFT | > m_seed << DSI_PLL_M1_DIV_SHIFT; > > return 0; > @@ -293,7 +294,7 @@ u32 vlv_get_dsi_pclk(struct intel_encoder *encoder, int pipe_bpp) > struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base); > u32 dsi_clock, pclk; > u32 pll_ctl, pll_div; > - u32 m = 0, p = 0; > + u32 m = 0, p = 0, n; > int refclk = 25000; > int i; > > @@ -308,6 +309,10 @@ u32 vlv_get_dsi_pclk(struct intel_encoder *encoder, int pipe_bpp) > pll_ctl &= DSI_PLL_P1_POST_DIV_MASK; > pll_ctl = pll_ctl >> (DSI_PLL_P1_POST_DIV_SHIFT - 2); > > + /* N1 divisor */ > + n = (pll_div & DSI_PLL_N1_DIV_MASK) >> DSI_PLL_N1_DIV_SHIFT; > + n = 1 << n; /* register has log2(N1) */ > + > /* mask out the other bits and extract the M1 divisor */ > pll_div &= DSI_PLL_M1_DIV_MASK; > pll_div = pll_div >> DSI_PLL_M1_DIV_SHIFT; > @@ -335,7 +340,7 @@ u32 vlv_get_dsi_pclk(struct intel_encoder *encoder, int pipe_bpp) > > m = i + 62; > > - dsi_clock = (m * refclk) / p; > + dsi_clock = (m * refclk) / (p * n); > > /* pixel_format and pipe_bpp should agree */ > assert_bpp_mismatch(intel_dsi->pixel_format, pipe_bpp); > -- > 2.1.4
diff --git a/drivers/gpu/drm/i915/intel_dsi_pll.c b/drivers/gpu/drm/i915/intel_dsi_pll.c index 9ada06ec88e5..effb561e00a0 100644 --- a/drivers/gpu/drm/i915/intel_dsi_pll.c +++ b/drivers/gpu/drm/i915/intel_dsi_pll.c @@ -160,7 +160,7 @@ static u32 dsi_clk_from_pclk(u32 pclk, int pixel_format, int lane_count) static int dsi_calc_mnp(int target_dsi_clk, struct dsi_mnp *dsi_mnp) { unsigned int calc_m = 0, calc_p = 0; - unsigned int m, n, p; + unsigned int m, n = 1, p; int ref_clk = 25000; int delta = target_dsi_clk; u32 m_seed; @@ -177,7 +177,7 @@ static int dsi_calc_mnp(int target_dsi_clk, struct dsi_mnp *dsi_mnp) * Find the optimal m and p divisors with minimal delta * +/- the required clock */ - int calc_dsi_clk = (m * ref_clk) / p; + int calc_dsi_clk = (m * ref_clk) / (p * n); int d = abs(target_dsi_clk - calc_dsi_clk); if (d < delta) { delta = d; @@ -187,10 +187,11 @@ static int dsi_calc_mnp(int target_dsi_clk, struct dsi_mnp *dsi_mnp) } } + /* register has log2(N1), this works fine for powers of two */ + n = ffz(~(n)); m_seed = lfsr_converts[calc_m - 62]; - n = 1; dsi_mnp->dsi_pll_ctrl = 1 << (DSI_PLL_P1_POST_DIV_SHIFT + calc_p - 2); - dsi_mnp->dsi_pll_div = (n - 1) << DSI_PLL_N1_DIV_SHIFT | + dsi_mnp->dsi_pll_div = n << DSI_PLL_N1_DIV_SHIFT | m_seed << DSI_PLL_M1_DIV_SHIFT; return 0; @@ -293,7 +294,7 @@ u32 vlv_get_dsi_pclk(struct intel_encoder *encoder, int pipe_bpp) struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base); u32 dsi_clock, pclk; u32 pll_ctl, pll_div; - u32 m = 0, p = 0; + u32 m = 0, p = 0, n; int refclk = 25000; int i; @@ -308,6 +309,10 @@ u32 vlv_get_dsi_pclk(struct intel_encoder *encoder, int pipe_bpp) pll_ctl &= DSI_PLL_P1_POST_DIV_MASK; pll_ctl = pll_ctl >> (DSI_PLL_P1_POST_DIV_SHIFT - 2); + /* N1 divisor */ + n = (pll_div & DSI_PLL_N1_DIV_MASK) >> DSI_PLL_N1_DIV_SHIFT; + n = 1 << n; /* register has log2(N1) */ + /* mask out the other bits and extract the M1 divisor */ pll_div &= DSI_PLL_M1_DIV_MASK; pll_div = pll_div >> DSI_PLL_M1_DIV_SHIFT; @@ -335,7 +340,7 @@ u32 vlv_get_dsi_pclk(struct intel_encoder *encoder, int pipe_bpp) m = i + 62; - dsi_clock = (m * refclk) / p; + dsi_clock = (m * refclk) / (p * n); /* pixel_format and pipe_bpp should agree */ assert_bpp_mismatch(intel_dsi->pixel_format, pipe_bpp);
Currently DSI PLL N1 is hardcoded off. Make it possible to use it later. This should have no functional changes for now. Signed-off-by: Jani Nikula <jani.nikula@intel.com> --- drivers/gpu/drm/i915/intel_dsi_pll.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-)