1 // SPDX-License-Identifier: MIT 2 /* Copyright © 2025 Intel Corporation */ 3 4 #include <drm/drm_print.h> 5 6 #include "intel_display_core.h" 7 #include "intel_display_types.h" 8 #include "vlv_clock.h" 9 #include "vlv_sideband.h" 10 11 /* 12 * FIXME: The caching of hpll_freq and czclk_freq relies on the first calls 13 * occurring at a time when they can actually be read. This appears to be the 14 * case, but is somewhat fragile. Make the initialization explicit at a point 15 * where they can be reliably read. 16 */ 17 18 /* returns HPLL frequency in kHz */ 19 int vlv_clock_get_hpll_vco(struct drm_device *drm) 20 { 21 struct intel_display *display = to_intel_display(drm); 22 int hpll_freq, vco_freq[] = { 800, 1600, 2000, 2400 }; 23 24 if (!display->vlv_clock.hpll_freq) { 25 vlv_cck_get(display); 26 /* Obtain SKU information */ 27 hpll_freq = vlv_cck_read(display, CCK_FUSE_REG) & 28 CCK_FUSE_HPLL_FREQ_MASK; 29 vlv_cck_put(display); 30 31 display->vlv_clock.hpll_freq = vco_freq[hpll_freq] * 1000; 32 33 drm_dbg_kms(drm, "HPLL frequency: %d kHz\n", display->vlv_clock.hpll_freq); 34 } 35 36 return display->vlv_clock.hpll_freq; 37 } 38 39 static int vlv_clock_get_cck(struct drm_device *drm, 40 const char *name, u32 reg, int ref_freq) 41 { 42 struct intel_display *display = to_intel_display(drm); 43 u32 val; 44 int divider; 45 46 vlv_cck_get(display); 47 val = vlv_cck_read(display, reg); 48 vlv_cck_put(display); 49 50 divider = val & CCK_FREQUENCY_VALUES; 51 52 drm_WARN(drm, (val & CCK_FREQUENCY_STATUS) != 53 (divider << CCK_FREQUENCY_STATUS_SHIFT), 54 "%s change in progress\n", name); 55 56 return DIV_ROUND_CLOSEST(ref_freq << 1, divider + 1); 57 } 58 59 int vlv_clock_get_hrawclk(struct drm_device *drm) 60 { 61 /* RAWCLK_FREQ_VLV register updated from power well code */ 62 return vlv_clock_get_cck(drm, "hrawclk", CCK_DISPLAY_REF_CLOCK_CONTROL, 63 vlv_clock_get_hpll_vco(drm)); 64 } 65 66 int vlv_clock_get_czclk(struct drm_device *drm) 67 { 68 struct intel_display *display = to_intel_display(drm); 69 70 if (!display->vlv_clock.czclk_freq) { 71 display->vlv_clock.czclk_freq = vlv_clock_get_cck(drm, "czclk", CCK_CZ_CLOCK_CONTROL, 72 vlv_clock_get_hpll_vco(drm)); 73 drm_dbg_kms(drm, "CZ clock rate: %d kHz\n", display->vlv_clock.czclk_freq); 74 } 75 76 return display->vlv_clock.czclk_freq; 77 } 78 79 int vlv_clock_get_cdclk(struct drm_device *drm) 80 { 81 return vlv_clock_get_cck(drm, "cdclk", CCK_DISPLAY_CLOCK_CONTROL, 82 vlv_clock_get_hpll_vco(drm)); 83 } 84 85 int vlv_clock_get_gpll(struct drm_device *drm) 86 { 87 return vlv_clock_get_cck(drm, "GPLL ref", CCK_GPLL_CLOCK_CONTROL, 88 vlv_clock_get_czclk(drm)); 89 } 90