drm/mgag200: Store values (not bits) in struct mgag200_pll_values

The fields in struct mgag200_pll_values currently hold the bits of
each register. Store the PLL values instead and let the PLL-update
code figure out the bits for each register.

Until now, the compute function either stored plain values or register
bits in struct mgag200_pll_values. The rsp update function used the
values as-is. This made it very hard to correctly interpret the stored
values (e.g., for logging or debugging). With the cleanup, the stored
values now have a clear meaning.

v2:
	* add a bit more context in the commit message (Sam)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210714142240.21979-7-tzimmermann@suse.de

diff --git a/drivers/gpu/drm/mgag200/mgag200_mode.c b/drivers/gpu/drm/mgag200/mgag200_mode.c
index 6085d807bb203504c4966ba657ad93c0133dd01b..6e730435357d5aa866c1f186e169f8c6a0a9ca0d 100644 (file)
--- a/drivers/gpu/drm/mgag200/mgag200_mode.c
+++ b/drivers/gpu/drm/mgag200/mgag200_mode.c
@@ -123,7 +123,7 @@ static int mgag200_compute_pixpll_values_g200(struct mga_device *mdev, long cloc
        const int in_div_max = 6;
        const int feed_div_min = 7;
        const int feed_div_max = 127;
-       u8 testm, testn;
+       u8 testp, testm, testn;
        u8 n = 0, m = 0, p, s;
        long f_vco;
        long computed;
@@ -141,10 +141,11 @@ static int mgag200_compute_pixpll_values_g200(struct mga_device *mdev, long cloc
                clock = p_clk_min >> 3;
 
        f_vco = clock;
-       for (p = 0;
-            p <= post_div_max && f_vco < p_clk_min;
-            p = (p << 1) + 1, f_vco <<= 1)
+       for (testp = 0;
+            testp <= post_div_max && f_vco < p_clk_min;
+            testp = (testp << 1) + 1, f_vco <<= 1)
                ;
+       p = testp + 1;
 
        delta = clock;
 
@@ -157,12 +158,12 @@ static int mgag200_compute_pixpll_values_g200(struct mga_device *mdev, long cloc
                                tmp_delta = computed - f_vco;
                        if (tmp_delta < delta) {
                                delta = tmp_delta;
-                               m = testm;
-                               n = testn;
+                               m = testm + 1;
+                               n = testn + 1;
                        }
                }
        }
-       f_vco = ref_clk * (n + 1) / (m + 1);
+       f_vco = ref_clk * n / m;
        if (f_vco < 100000)
                s = 0;
        else if (f_vco < 140000)
@@ -186,11 +187,17 @@ static int mgag200_compute_pixpll_values_g200(struct mga_device *mdev, long cloc
 static void mgag200_set_pixpll_g200(struct mga_device *mdev,
                                    const struct mgag200_pll_values *pixpllc)
 {
+       unsigned int pixpllcm, pixpllcn, pixpllcp, pixpllcs;
        u8 xpixpllcm, xpixpllcn, xpixpllcp;
 
-       xpixpllcm = pixpllc->m;
-       xpixpllcn = pixpllc->n;
-       xpixpllcp = pixpllc->p | (pixpllc->s << 3);
+       pixpllcm = pixpllc->m - 1;
+       pixpllcn = pixpllc->n - 1;
+       pixpllcp = pixpllc->p - 1;
+       pixpllcs = pixpllc->s;
+
+       xpixpllcm = pixpllcm;
+       xpixpllcn = pixpllcn;
+       xpixpllcp = (pixpllcs << 3) | pixpllcp;
 
        WREG_MISC_MASKED(MGAREG_MISC_CLKSEL_MGA, MGAREG_MISC_CLKSEL_MASK);
 
@@ -238,9 +245,9 @@ static int mgag200_compute_pixpll_values_g200se(struct mga_device *mdev, long cl
                                                tmpdelta = clock - computed;
                                        if (tmpdelta < delta) {
                                                delta = tmpdelta;
-                                               m = testm - 1;
-                                               n = testn - 1;
-                                               p = testp - 1;
+                                               m = testm;
+                                               n = testn;
+                                               p = testp;
                                        }
                                }
                        }
@@ -278,22 +285,19 @@ static int mgag200_compute_pixpll_values_g200se(struct mga_device *mdev, long cl
 
                                        if (tmpdelta < delta) {
                                                delta = tmpdelta;
-                                               m = testm - 1;
-                                               n = testn - 1;
-                                               p = testp - 1;
+                                               m = testm;
+                                               n = testn;
+                                               p = testp;
                                        }
                                }
                        }
                }
 
-               fvv = pllreffreq * (n + 1) / (m + 1);
+               fvv = pllreffreq * n / m;
                fvv = (fvv - 800000) / 50000;
-
                if (fvv > 15)
                        fvv = 15;
-
-               p |= (fvv << 4);
-               m |= 0x80;
+               s = fvv << 1;
 
                clock = clock / 2;
        }
@@ -315,11 +319,17 @@ static void mgag200_set_pixpll_g200se(struct mga_device *mdev,
                                      const struct mgag200_pll_values *pixpllc)
 {
        u32 unique_rev_id = mdev->model.g200se.unique_rev_id;
+       unsigned int pixpllcm, pixpllcn, pixpllcp, pixpllcs;
        u8 xpixpllcm, xpixpllcn, xpixpllcp;
 
-       xpixpllcm = pixpllc->m;
-       xpixpllcn = pixpllc->n;
-       xpixpllcp = pixpllc->p | (pixpllc->s << 3);
+       pixpllcm = pixpllc->m - 1;
+       pixpllcn = pixpllc->n - 1;
+       pixpllcp = pixpllc->p - 1;
+       pixpllcs = pixpllc->s;
+
+       xpixpllcm = pixpllcm | ((pixpllcn & BIT(8)) >> 1);
+       xpixpllcn = pixpllcn;
+       xpixpllcp = (pixpllcs << 3) | pixpllcp;
 
        WREG_MISC_MASKED(MGAREG_MISC_CLKSEL_MGA, MGAREG_MISC_CLKSEL_MASK);
 
@@ -348,7 +358,6 @@ static int mgag200_compute_pixpll_values_g200wb(struct mga_device *mdev, long cl
        delta = 0xffffffff;
 
        if (mdev->type == G200_EW3) {
-
                vcomax = 800000;
                vcomin = 400000;
                pllreffreq = 25000;
@@ -371,19 +380,16 @@ static int mgag200_compute_pixpll_values_g200wb(struct mga_device *mdev, long cl
                                                        tmpdelta = clock - computed;
                                                if (tmpdelta < delta) {
                                                        delta = tmpdelta;
-                                                       m = ((testn & 0x100) >> 1) |
-                                                               (testm);
-                                                       n = (testn & 0xFF);
-                                                       p = ((testn & 0x600) >> 3) |
-                                                               (testp2 << 3) |
-                                                               (testp);
+                                                       m = testm + 1;
+                                                       n = testn + 1;
+                                                       p = testp + 1;
+                                                       s = testp2;
                                                }
                                        }
                                }
                        }
                }
        } else {
-
                vcomax = 550000;
                vcomin = 150000;
                pllreffreq = 48000;
@@ -404,10 +410,10 @@ static int mgag200_compute_pixpll_values_g200wb(struct mga_device *mdev, long cl
                                                tmpdelta = clock - computed;
                                        if (tmpdelta < delta) {
                                                delta = tmpdelta;
-                                               n = testn - 1;
-                                               m = (testm - 1) |
-                                                       ((n >> 1) & 0x80);
-                                               p = testp - 1;
+                                               n = testn;
+                                               m = testm;
+                                               p = testp;
+                                               s = 0;
                                        }
                                }
                        }
@@ -425,13 +431,19 @@ static int mgag200_compute_pixpll_values_g200wb(struct mga_device *mdev, long cl
 static void mgag200_set_pixpll_g200wb(struct mga_device *mdev,
                                      const struct mgag200_pll_values *pixpllc)
 {
+       unsigned int pixpllcm, pixpllcn, pixpllcp, pixpllcs;
        u8 xpixpllcm, xpixpllcn, xpixpllcp, tmp;
        int i, j, tmpcount, vcount;
        bool pll_locked = false;
 
-       xpixpllcm = pixpllc->m;
-       xpixpllcn = pixpllc->n;
-       xpixpllcp = pixpllc->p | (pixpllc->s << 3);
+       pixpllcm = pixpllc->m - 1;
+       pixpllcn = pixpllc->n - 1;
+       pixpllcp = pixpllc->p - 1;
+       pixpllcs = pixpllc->s;
+
+       xpixpllcm = ((pixpllcn & BIT(8)) >> 1) | pixpllcm;
+       xpixpllcn = pixpllcn;
+       xpixpllcp = ((pixpllcn & GENMASK(10, 9)) >> 3) | (pixpllcs << 3) | pixpllcp;
 
        WREG_MISC_MASKED(MGAREG_MISC_CLKSEL_MGA, MGAREG_MISC_CLKSEL_MASK);
 
@@ -564,9 +576,9 @@ static int mgag200_compute_pixpll_values_g200ev(struct mga_device *mdev, long cl
                                        tmpdelta = clock - computed;
                                if (tmpdelta < delta) {
                                        delta = tmpdelta;
-                                       n = testn - 1;
-                                       m = testm - 1;
-                                       p = testp - 1;
+                                       n = testn;
+                                       m = testm;
+                                       p = testp;
                                }
                        }
                }
@@ -583,11 +595,17 @@ static int mgag200_compute_pixpll_values_g200ev(struct mga_device *mdev, long cl
 static void mgag200_set_pixpll_g200ev(struct mga_device *mdev,
                                      const struct mgag200_pll_values *pixpllc)
 {
+       unsigned int pixpllcm, pixpllcn, pixpllcp, pixpllcs;
        u8 xpixpllcm, xpixpllcn, xpixpllcp, tmp;
 
-       xpixpllcm = pixpllc->m;
-       xpixpllcn = pixpllc->n;
-       xpixpllcp = pixpllc->p | (pixpllc->s << 3);
+       pixpllcm = pixpllc->m - 1;
+       pixpllcn = pixpllc->n - 1;
+       pixpllcp = pixpllc->p - 1;
+       pixpllcs = pixpllc->s;
+
+       xpixpllcm = pixpllcm;
+       xpixpllcn = pixpllcn;
+       xpixpllcp = (pixpllcs << 3) | pixpllcp;
 
        WREG_MISC_MASKED(MGAREG_MISC_CLKSEL_MGA, MGAREG_MISC_CLKSEL_MASK);
 
@@ -675,9 +693,9 @@ static int mgag200_compute_pixpll_values_g200eh(struct mga_device *mdev, long cl
                                        tmpdelta = clock - computed;
                                if (tmpdelta < delta) {
                                        delta = tmpdelta;
-                                       n = testn;
-                                       m = testm;
-                                       p = testp;
+                                       n = testn + 1;
+                                       m = testm + 1;
+                                       p = testp + 1;
                                }
                                if (delta == 0)
                                        break;
@@ -709,12 +727,10 @@ static int mgag200_compute_pixpll_values_g200eh(struct mga_device *mdev, long cl
                                                tmpdelta = clock - computed;
                                        if (tmpdelta < delta) {
                                                delta = tmpdelta;
-                                               n = testn - 1;
-                                               m = (testm - 1);
-                                               p = testp - 1;
+                                               n = testn;
+                                               m = testm;
+                                               p = testp;
                                        }
-                                       if ((clock * testp) >= 600000)
-                                               p |= 0x80;
                                }
                        }
                }
@@ -731,13 +747,19 @@ static int mgag200_compute_pixpll_values_g200eh(struct mga_device *mdev, long cl
 static void mgag200_set_pixpll_g200eh(struct mga_device *mdev,
                                      const struct mgag200_pll_values *pixpllc)
 {
+       unsigned int pixpllcm, pixpllcn, pixpllcp, pixpllcs;
        u8 xpixpllcm, xpixpllcn, xpixpllcp, tmp;
        int i, j, tmpcount, vcount;
        bool pll_locked = false;
 
-       xpixpllcm = pixpllc->m;
-       xpixpllcn = pixpllc->n;
-       xpixpllcp = pixpllc->p | (pixpllc->s << 3);
+       pixpllcm = pixpllc->m - 1;
+       pixpllcn = pixpllc->n - 1;
+       pixpllcp = pixpllc->p - 1;
+       pixpllcs = pixpllc->s;
+
+       xpixpllcm = ((pixpllcn & BIT(8)) >> 1) | pixpllcm;
+       xpixpllcn = pixpllcn;
+       xpixpllcp = (pixpllcs << 3) | pixpllcp;
 
        WREG_MISC_MASKED(MGAREG_MISC_CLKSEL_MGA, MGAREG_MISC_CLKSEL_MASK);
 
@@ -830,9 +852,10 @@ static int mgag200_compute_pixpll_values_g200er(struct mga_device *mdev, long cl
                                                tmpdelta = clock - computed;
                                        if (tmpdelta < delta) {
                                                delta = tmpdelta;
-                                               m = testm | (testo << 3);
-                                               n = testn;
-                                               p = testr | (testr << 3);
+                                               m = (testm | (testo << 3)) + 1;
+                                               n = testn + 1;
+                                               p = testr + 1;
+                                               s = testr;
                                        }
                                }
                        }
@@ -850,11 +873,17 @@ static int mgag200_compute_pixpll_values_g200er(struct mga_device *mdev, long cl
 static void mgag200_set_pixpll_g200er(struct mga_device *mdev,
                                      const struct mgag200_pll_values *pixpllc)
 {
+       unsigned int pixpllcm, pixpllcn, pixpllcp, pixpllcs;
        u8 xpixpllcm, xpixpllcn, xpixpllcp, tmp;
 
-       xpixpllcm = pixpllc->m;
-       xpixpllcn = pixpllc->n;
-       xpixpllcp = pixpllc->p | (pixpllc->s << 3);
+       pixpllcm = pixpllc->m - 1;
+       pixpllcn = pixpllc->n - 1;
+       pixpllcp = pixpllc->p - 1;
+       pixpllcs = pixpllc->s;
+
+       xpixpllcm = pixpllcm;
+       xpixpllcn = pixpllcn;
+       xpixpllcp = (pixpllcs << 3) | pixpllcp;
 
        WREG_MISC_MASKED(MGAREG_MISC_CLKSEL_MGA, MGAREG_MISC_CLKSEL_MASK);