root/src/add-ons/accelerants/nvidia/engine/nv_dac2.c
/* program the secondary DAC */
/* Author:
   Rudolf Cornelissen 12/2003-5/2021
*/

#define MODULE_BIT 0x00001000

#include "nv_std.h"

static void nv_dac2_dump_pix_pll(void);
static status_t nv10_nv20_dac2_pix_pll_find(
        display_mode target,float * calc_pclk,uint8 * m_result,uint8 * n_result,uint8 * p_result, uint8 test);

/* see if an analog VGA monitor is connected to connector #2 */
bool nv_dac2_crt_connected()
{
        uint32 output, dac;
        bool present;

        switch(si->ps.card_type) {
        /* NOTE:
         * NV11 can't do this: It will report DAC1 status instead because it HAS no
         * actual secondary DAC function. */
        /* (It DOES have a secondary palette RAM and pixelclock PLL though.) */
        case NV11:
        /* on NV40 arch (confirmed NV43, G71, G73) this routine doesn't work. */
        /* (on NV44 (confirmed Geforce 6200LE) this routine *does* work.) */
        case NV43:
        case G71:
        case G73:
                LOG(4,("DAC2: no load detection available. reporting no CRT detected on connector #2\n"));
                return false;
        }

        /* save output connector setting */
        output = DAC2R(OUTPUT);
        /* save DAC state */
        dac = DAC2R(TSTCTRL);

        /* turn on DAC2 */
        DAC2W(TSTCTRL, (DAC2R(TSTCTRL) & 0xfffeffff));
        /* select primary CRTC (head) and turn off CRT (and DVI?) outputs */
        DAC2W(OUTPUT, (output & 0x0000feee));
        /* wait for signal lines to stabilize */
        snooze(1000);
        /* re-enable CRT output */
        DAC2W(OUTPUT, (DAC2R(OUTPUT) | 0x00000001));

        /* setup RGB test signal levels to approx 30% of DAC range and enable them
         * (NOTE: testsignal function block resides in DAC1 only (!)) */
        DACW(TSTDATA, ((0x2 << 30) | (0x140 << 20) | (0x140 << 10) | (0x140 << 0)));
        /* route test signals to output
         * (NOTE: testsignal function block resides in DAC1 only (!)) */
        DACW(TSTCTRL, (DACR(TSTCTRL) | 0x00001000));
        /* wait for signal lines to stabilize */
        snooze(1000);

        /* do actual detection: all signals paths high == CRT connected */
        if (DAC2R(TSTCTRL) & 0x10000000)
        {
                present = true;
                LOG(4,("DAC2: CRT detected on connector #2\n"));
        }
        else
        {
                present = false;
                LOG(4,("DAC2: no CRT detected on connector #2\n"));
        }

        /* kill test signal routing
         * (NOTE: testsignal function block resides in DAC1 only (!)) */
        DACW(TSTCTRL, (DACR(TSTCTRL) & 0xffffefff));

        /* restore output connector setting */
        DAC2W(OUTPUT, output);
        /* restore DAC state */
        DAC2W(TSTCTRL, dac);

        return present;
}

/*set the mode, brightness is a value from 0->2 (where 1 is equivalent to direct)*/
status_t nv_dac2_mode(int mode,float brightness)
{
        uint8 *r,*g,*b;
        int i, ri;

        /*set colour arrays to point to space reserved in shared info*/
        r = si->color_data;
        g = r + 256;
        b = g + 256;

        LOG(4,("DAC2: Setting screen mode %d brightness %f\n", mode, brightness));
        /* init the palette for brightness specified */
        /* (Nvidia cards always use MSbits from screenbuffer as index for PAL) */
        for (i = 0; i < 256; i++)
        {
                ri = i * brightness;
                if (ri > 255) ri = 255;
                b[i] = g[i] = r[i] = ri;
        }

        if (nv_dac2_palette(r,g,b) != B_OK) return B_ERROR;

        /* disable palette RAM adressing mask */
        NV_REG8(NV8_PAL2MASK) = 0xff;
        LOG(2,("DAC2: PAL pixrdmsk readback $%02x\n", NV_REG8(NV8_PAL2MASK)));

        return B_OK;
}

/*program the DAC palette using the given r,g,b values*/
status_t nv_dac2_palette(uint8 r[256],uint8 g[256],uint8 b[256])
{
        int i;

        LOG(4,("DAC2: setting palette\n"));

        /* select first PAL adress before starting programming */
        NV_REG8(NV8_PAL2INDW) = 0x00;

        /* loop through all 256 to program DAC */
        for (i = 0; i < 256; i++)
        {
                /* the 6 implemented bits are on b0-b5 of the bus */
                NV_REG8(NV8_PAL2DATA) = r[i];
                NV_REG8(NV8_PAL2DATA) = g[i];
                NV_REG8(NV8_PAL2DATA) = b[i];
        }
        if (NV_REG8(NV8_PAL2INDW) != 0x00)
        {
                LOG(8,("DAC2: PAL write index incorrect after programming\n"));
                return B_ERROR;
        }
if (1)
 {//reread LUT
        uint8 R, G, B;

        /* select first PAL adress to read (modulo 3 counter) */
        NV_REG8(NV8_PAL2INDR) = 0x00;
        for (i = 0; i < 256; i++)
        {
                R = NV_REG8(NV8_PAL2DATA);
                G = NV_REG8(NV8_PAL2DATA);
                B = NV_REG8(NV8_PAL2DATA);
                if ((r[i] != R) || (g[i] != G) || (b[i] != B)) 
                        LOG(1,("DAC2 palette %d: w %x %x %x, r %x %x %x\n", i, r[i], g[i], b[i], R, G, B)); // apsed
        }
 }

        return B_OK;
}

/*program the pixpll - frequency in kHz*/
status_t nv_dac2_set_pix_pll(display_mode target)
{
        uint8 m=0,n=0,p=0;

        float pix_setting, req_pclk;
        status_t result;

        /* fix a DVI or laptop flatpanel to 60Hz refresh! */
        /* Note:
         * The pixelclock drives the flatpanel modeline, not the CRTC modeline. */
        if (si->ps.monitors & CRTC2_TMDS)
        {
                LOG(4,("DAC2: Fixing DFP refresh to 60Hz!\n"));

                /* use the panel's modeline to determine the needed pixelclock */
                target.timing.pixel_clock = si->ps.p2_timing.pixel_clock;
        }

        req_pclk = (target.timing.pixel_clock)/1000.0;

        /* signal that we actually want to set the mode */
        result = nv_dac2_pix_pll_find(target,&pix_setting,&m,&n,&p, 1);
        if (result != B_OK) return result;

        /* dump old setup for learning purposes */
        nv_dac2_dump_pix_pll();

        /* some logging for learning purposes */
        LOG(4,("DAC2: current NV30_PLLSETUP settings: $%08x\n", DACR(NV30_PLLSETUP)));
        /* this register seems to (dis)connect functions blocks and PLLs:
         * there seem to be two PLL types per function block (on some cards),
         * b16-17 DAC1clk, b18-19 DAC2clk, b20-21 GPUclk, b22-23 MEMclk. */
        LOG(4,("DAC2: current (0x0000c040) settings: $%08x\n", NV_REG32(0x0000c040)));

        /* disable spread spectrum modes for the pixelPLLs _first_ */
        /* spread spectrum: b0,1 = GPUclk, b2,3 = MEMclk, b4,5 = DAC1clk, b6,7 = DAC2clk;
         * b16-19 influence clock routing to digital outputs (internal/external LVDS transmitters?) */
        if (si->ps.card_arch >= NV30A)
                DACW(NV30_PLLSETUP, (DACR(NV30_PLLSETUP) & ~0x000000f0));

        /* we offer this option because some panels have very tight restrictions,
         * and there's no overlapping settings range that makes them all work.
         * note:
         * this assumes the cards BIOS correctly programmed the panel (is likely) */
        //fixme: when VESA DDC EDID stuff is implemented, this option can be deleted...
        if ((si->ps.monitors & CRTC2_TMDS) && !si->settings.pgm_panel) {
                LOG(4,("DAC2: Not programming DFP refresh (specified in nvidia.settings)\n"));
        } else {
                LOG(4,("DAC2: Setting PIX PLL for pixelclock %f\n", req_pclk));

                /* program new frequency */
                DAC2W(PIXPLLC, ((p << 16) | (n << 8) | m));

                /* program 2nd set N and M scalers if they exist (b31=1 enables them) */
                if (si->ps.ext_pll) DAC2W(PIXPLLC2, 0x80000401);

                /* Give the PIXPLL frequency some time to lock... (there's no indication bit available) */
                snooze(1000);

                LOG(2,("DAC2: PIX PLL frequency should be locked now...\n"));
        }

        /* enable programmable PLLs */
        /* (confirmed PLLSEL to be a write-only register on NV04 and NV11!) */
        /* note:
         * setup PLL assignment _after_ programming PLL */
        if (si->ps.card_arch < NV40A) {
                DACW(PLLSEL, 0x30000f00);
        } else {
                DACW(NV40_PLLSEL2, (DACR(NV40_PLLSEL2) & ~0x10000100));
                DACW(PLLSEL, 0x30000f04);
        }

        return B_OK;
}

static void nv_dac2_dump_pix_pll(void)
{
        uint32 dividers1, dividers2;
        uint8 m1, n1, p1;
        uint8 m2 = 1, n2 = 1;
        float f_vco, f_phase, f_pixel;

        LOG(2,("DAC2: dumping current pixelPLL settings:\n"));

        dividers1 = DAC2R(PIXPLLC);
        m1 = (dividers1 & 0x000000ff);
        n1 = (dividers1 & 0x0000ff00) >> 8;
        p1 = 0x01 << ((dividers1 & 0x00070000) >> 16);
        LOG(2,("DAC2: divider1 settings ($%08x): M1=%d, N1=%d, P1=%d\n", dividers1, m1, n1, p1));

        if (si->ps.ext_pll) {
                dividers2 = DAC2R(PIXPLLC2);
                if (dividers2 & 0x80000000) {
                        /* the extended PLL part is enabled */
                        m2 = (dividers2 & 0x000000ff);
                        n2 = (dividers2 & 0x0000ff00) >> 8;
                        LOG(2,("DAC2: divider2 is enabled, settings ($%08x): M2=%d, N2=%d\n", dividers2, m2, n2));
                } else {
                        LOG(2,("DAC2: divider2 is disabled ($%08x)\n", dividers2));
                }
        }

        /* log the frequencies found */
        f_phase = si->ps.f_ref / (m1 * m2);
        f_vco = (f_phase * n1 * n2);
        f_pixel = f_vco / p1;

        LOG(2,("DAC2: phase discriminator frequency is %fMhz\n", f_phase));
        LOG(2,("DAC2: VCO frequency is %fMhz\n", f_vco));
        LOG(2,("DAC2: pixelclock is %fMhz\n", f_pixel));
        LOG(2,("DAC2: end of dump.\n"));

        /* apparantly if a VESA modecall during boot fails we need to explicitly select the PLL's
         * again (was already done during driver init) if we readout the current PLL setting.. */
        DACW(PLLSEL, 0x30000f00);
}

/* find nearest valid pix pll */
status_t nv_dac2_pix_pll_find
        (display_mode target,float * calc_pclk,uint8 * m_result,uint8 * n_result,uint8 * p_result, uint8 test)
{
        switch (si->ps.card_type) {
                default:   return nv10_nv20_dac2_pix_pll_find(target, calc_pclk, m_result, n_result, p_result, test);
        }
        return B_ERROR;
}


/* find nearest valid pixel PLL setting */
static status_t nv10_nv20_dac2_pix_pll_find(
        display_mode target, float* calc_pclk, uint8* m_result, uint8* n_result,
        uint8* p_result, uint8 test)
{
        int m = 0, n = 0, p = 0, m_min = 7, p_max = 0x10;
        float error, error_best = INFINITY;
        int best[3] = {0, 0, 0};
        float f_vco, max_pclk;
        float req_pclk = target.timing.pixel_clock/1000.0;

        LOG(4, ("DAC2: NV10/NV20 restrictions apply\n"));

        /* determine the max. pixelclock for the current videomode */
        switch (target.space)
        {
                case B_CMAP8:
                        max_pclk = si->ps.max_dac2_clock_8;
                        break;
                case B_RGB15_LITTLE:
                case B_RGB16_LITTLE:
                        max_pclk = si->ps.max_dac2_clock_16;
                        break;
                case B_RGB24_LITTLE:
                        max_pclk = si->ps.max_dac2_clock_24;
                        break;
                case B_RGB32_LITTLE:
                        max_pclk = si->ps.max_dac2_clock_32;
                        break;
                default:
                        /* use fail-safe value */
                        max_pclk = si->ps.max_dac2_clock_32;
                        break;
        }
        /* update PLL divider specs for C51 chipset */
        if ((CFGR(DEVID) & 0xfff0ffff) == 0x024010de) {
                m_min = 4;
                p_max = 0x20;
        }
        /* if some dualhead mode is active, an extra restriction might apply */
        if ((target.flags & DUALHEAD_BITS) && (target.space == B_RGB32_LITTLE))
                max_pclk = si->ps.max_dac2_clock_32dh;

        /* Make sure the requested pixelclock is within the PLL's operational limits */
        /* lower limit is min_pixel_vco divided by highest postscaler-factor */
        if (req_pclk < (si->ps.min_video_vco / p_max))
        {
                LOG(4,("DAC2: clamping pixclock: requested %fMHz, set to %fMHz\n",
                                                                                req_pclk, (float)(si->ps.min_video_vco / p_max)));
                req_pclk = (si->ps.min_video_vco / p_max);
        }
        /* upper limit is given by pins in combination with current active mode */
        if (req_pclk > max_pclk)
        {
                LOG(4,("DAC2: clamping pixclock: requested %fMHz, set to %fMHz\n",
                                                                                                                req_pclk, (float)max_pclk));
                req_pclk = max_pclk;
        }

        /* iterate through all valid PLL postscaler settings */
        for (p=0x01; p <= p_max; p = p<<1)
        {
                /* calculate the needed VCO frequency for this postscaler setting */
                f_vco = req_pclk * p;

                /* check if this is within range of the VCO specs */
                if ((f_vco >= si->ps.min_video_vco) && (f_vco <= si->ps.max_video_vco))
                {
                        /* FX5600 and FX5700 tweak for 2nd set N and M scalers */
                        if (si->ps.ext_pll) f_vco /= 4;

                        /* iterate trough all valid reference-frequency postscaler settings */
                        for (m = m_min; m <= 14; m++)
                        {
                                /* check if phase-discriminator will be within operational limits */
                                //fixme: PLL calcs will be resetup/splitup/updated...
                                if (si->ps.card_type == NV36) {
                                        if (((si->ps.f_ref / m) < 3.2) || ((si->ps.f_ref / m) > 6.4)) continue;
                                } else {
                                        if ((CFGR(DEVID) & 0xfff0ffff) == 0x024010de) {
                                                /* C51 chipset */
                                                if (((si->ps.f_ref / m) < 1.7) || ((si->ps.f_ref / m) > 6.4)) continue;
                                        } else {
                                                if (((si->ps.f_ref / m) < 1.0) || ((si->ps.f_ref / m) > 2.0)) continue;
                                        }
                                }

                                /* calculate VCO postscaler setting for current setup.. */
                                n = (int)(((f_vco * m) / si->ps.f_ref) + 0.5);
                                /* ..and check for validity */
                                if ((n < 1) || (n > 255))       continue;

                                /* find error in frequency this setting gives */
                                if (si->ps.ext_pll)
                                {
                                        /* FX5600 and FX5700 tweak for 2nd set N and M scalers */
                                        error = fabs((req_pclk / 4) - (((si->ps.f_ref / m) * n) / p));
                                }
                                else
                                        error = fabs(req_pclk - (((si->ps.f_ref / m) * n) / p));

                                /* note the setting if best yet */
                                if (error < error_best)
                                {
                                        error_best = error;
                                        best[0]=m;
                                        best[1]=n;
                                        best[2]=p;
                                }
                        }
                }
        }

        /* setup the scalers programming values for found optimum setting */
        m = best[0];
        n = best[1];
        p = best[2];

        /* log the VCO frequency found */
        f_vco = ((si->ps.f_ref / m) * n);
        /* FX5600 and FX5700 tweak for 2nd set N and M scalers */
        if (si->ps.ext_pll) f_vco *= 4;

        LOG(2,("DAC2: pix VCO frequency found %fMhz\n", f_vco));

        /* return the results */
        *calc_pclk = (f_vco / p);
        *m_result = m;
        *n_result = n;
        switch(p)
        {
        case 1:
                p = 0x00;
                break;
        case 2:
                p = 0x01;
                break;
        case 4:
                p = 0x02;
                break;
        case 8:
                p = 0x03;
                break;
        case 16:
                p = 0x04;
                break;
        case 32:
                p = 0x05;
                break;
        }
        *p_result = p;

        /* display the found pixelclock values */
        LOG(2,("DAC2: pix PLL check: requested %fMHz got %fMHz, mnp 0x%02x 0x%02x 0x%02x\n",
                req_pclk, *calc_pclk, *m_result, *n_result, *p_result));

        return B_OK;
}