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Commit 44d4c6ee authored by Shobhit Kumar's avatar Shobhit Kumar Committed by Daniel Vetter
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drm/i915: Compute dsi_clk from pixel clock 

Pixel clock based calculation is recommended in the MIPI host controller
documentation

v2: Based on review comments from Jani and Ville
    - Use dsi_clk in KHz rather than converting in Hz and back to MHz
    - RR formula is retained though not used but return dsi_clk in KHz now
    - Moved the m-n-p changes into a separate patch
    - Removed the parameter check for intel_dsi->dsi_clock_freq. This will be
      bought back in if needed when appropriate panel drivers are done

v3: Removed the unused mnp calculation from static table
Signed-off-by: default avatarVijayakumar Balakrishnan <vijayakumar.balakrishnan@intel.com>
Signed-off-by: default avatarShobhit Kumar <shobhit.kumar@intel.com>
Reviewed-by: default avatarJani Nikula <jani.nikula@intel.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
parent e9fe51c6
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Showing with 31 additions and 58 deletions
drivers/gpu/drm/i915/intel_dsi_pll.c
View file @ 44d4c6ee
......@@ -50,6 +50,8 @@ static const u32 lfsr_converts[] = {
71, 35 /* 91 - 92 */
};
#ifdef DSI_CLK_FROM_RR
static u32 dsi_rr_formula(const struct drm_display_mode *mode,
int pixel_format, int video_mode_format,
int lane_count, bool eotp)
......@@ -121,7 +123,7 @@ static u32 dsi_rr_formula(const struct drm_display_mode *mode,
/* the dsi clock is divided by 2 in the hardware to get dsi ddr clock */
dsi_bit_clock_hz = bytes_per_x_frames_x_lanes * 8;
dsi_clk = dsi_bit_clock_hz / (1000 * 1000);
dsi_clk = dsi_bit_clock_hz / 1000;
if (eotp && video_mode_format == VIDEO_MODE_BURST)
dsi_clk *= 2;
......@@ -129,64 +131,37 @@ static u32 dsi_rr_formula(const struct drm_display_mode *mode,
return dsi_clk;
}
#ifdef MNP_FROM_TABLE
struct dsi_clock_table {
u32 freq;
u8 m;
u8 p;
};
static const struct dsi_clock_table dsi_clk_tbl[] = {
{300, 72, 6}, {313, 75, 6}, {323, 78, 6}, {333, 80, 6},
{343, 82, 6}, {353, 85, 6}, {363, 87, 6}, {373, 90, 6},
{383, 92, 6}, {390, 78, 5}, {393, 79, 5}, {400, 80, 5},
{401, 80, 5}, {402, 80, 5}, {403, 81, 5}, {404, 81, 5},
{405, 81, 5}, {406, 81, 5}, {407, 81, 5}, {408, 82, 5},
{409, 82, 5}, {410, 82, 5}, {411, 82, 5}, {412, 82, 5},
{413, 83, 5}, {414, 83, 5}, {415, 83, 5}, {416, 83, 5},
{417, 83, 5}, {418, 84, 5}, {419, 84, 5}, {420, 84, 5},
{430, 86, 5}, {440, 88, 5}, {450, 90, 5}, {460, 92, 5},
{470, 75, 4}, {480, 77, 4}, {490, 78, 4}, {500, 80, 4},
{510, 82, 4}, {520, 83, 4}, {530, 85, 4}, {540, 86, 4},
{550, 88, 4}, {560, 90, 4}, {570, 91, 4}, {580, 70, 3},
{590, 71, 3}, {600, 72, 3}, {610, 73, 3}, {620, 74, 3},
{630, 76, 3}, {640, 77, 3}, {650, 78, 3}, {660, 79, 3},
{670, 80, 3}, {680, 82, 3}, {690, 83, 3}, {700, 84, 3},
{710, 85, 3}, {720, 86, 3}, {730, 88, 3}, {740, 89, 3},
{750, 90, 3}, {760, 91, 3}, {770, 92, 3}, {780, 62, 2},
{790, 63, 2}, {800, 64, 2}, {880, 70, 2}, {900, 72, 2},
{1000, 80, 2}, /* dsi clock frequency in Mhz*/
};
#else
static int dsi_calc_mnp(u32 dsi_clk, struct dsi_mnp *dsi_mnp)
/* Get DSI clock from pixel clock */
static u32 dsi_clk_from_pclk(const struct drm_display_mode *mode,
int pixel_format, int lane_count)
{
unsigned int i;
u8 m;
u8 n;
u8 p;
u32 m_seed;
if (dsi_clk < 300 || dsi_clk > 1000)
return -ECHRNG;
u32 dsi_clk_khz;
u32 bpp;
for (i = 0; i <= ARRAY_SIZE(dsi_clk_tbl); i++) {
if (dsi_clk_tbl[i].freq > dsi_clk)
break;
switch (pixel_format) {
default:
case VID_MODE_FORMAT_RGB888:
case VID_MODE_FORMAT_RGB666_LOOSE:
bpp = 24;
break;
case VID_MODE_FORMAT_RGB666:
bpp = 18;
break;
case VID_MODE_FORMAT_RGB565:
bpp = 16;
break;
}
m = dsi_clk_tbl[i].m;
p = dsi_clk_tbl[i].p;
m_seed = lfsr_converts[m - 62];
n = 1;
dsi_mnp->dsi_pll_ctrl = 1 << (DSI_PLL_P1_POST_DIV_SHIFT + p - 2);
dsi_mnp->dsi_pll_div = (n - 1) << DSI_PLL_N1_DIV_SHIFT |
m_seed << DSI_PLL_M1_DIV_SHIFT;
/* DSI data rate = pixel clock * bits per pixel / lane count
pixel clock is converted from KHz to Hz */
dsi_clk_khz = DIV_ROUND_CLOSEST(mode->clock * bpp, lane_count);
return 0;
return dsi_clk_khz;
}
#else
#endif
static int dsi_calc_mnp(u32 dsi_clk, struct dsi_mnp *dsi_mnp)
{
......@@ -200,13 +175,14 @@ static int dsi_calc_mnp(u32 dsi_clk, struct dsi_mnp *dsi_mnp)
u32 calc_p;
u32 m_seed;
if (dsi_clk < 300 || dsi_clk > 1150) {
/* dsi_clk is expected in KHZ */
if (dsi_clk < 300000 || dsi_clk > 1150000) {
DRM_ERROR("DSI CLK Out of Range\n");
return -ECHRNG;
}
ref_clk = 25000;
target_dsi_clk = dsi_clk * 1000;
target_dsi_clk = dsi_clk;
error = 0xFFFFFFFF;
calc_m = 0;
calc_p = 0;
......@@ -235,8 +211,6 @@ static int dsi_calc_mnp(u32 dsi_clk, struct dsi_mnp *dsi_mnp)
return 0;
}
#endif
/*
* XXX: The muxing and gating is hard coded for now. Need to add support for
* sharing PLLs with two DSI outputs.
......@@ -251,9 +225,8 @@ static void vlv_configure_dsi_pll(struct intel_encoder *encoder)
struct dsi_mnp dsi_mnp;
u32 dsi_clk;
dsi_clk = dsi_rr_formula(mode, intel_dsi->pixel_format,
intel_dsi->video_mode_format,
intel_dsi->lane_count, !intel_dsi->eot_disable);
dsi_clk = dsi_clk_from_pclk(mode, intel_dsi->pixel_format,
intel_dsi->lane_count);
ret = dsi_calc_mnp(dsi_clk, &dsi_mnp);
if (ret) {
......
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