drm/nv50: support fractional feedback divider on newer chips

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

4 files changed, 120 insertions, 24 deletions

diff --git a/drivers/gpu/drm/nouveau/Makefile b/drivers/gpu/drm/nouveau/Makefile
index 453df3f6053f..acd31ed861ef 100644
--- a/drivers/gpu/drm/nouveau/Makefile
+++ b/drivers/gpu/drm/nouveau/Makefile
@@ -22,7 +22,8 @@ nouveau-y := nouveau_drv.o nouveau_state.o nouveau_channel.o nouveau_mem.o \
              nv50_cursor.o nv50_display.o nv50_fbcon.o \
              nv04_dac.o nv04_dfp.o nv04_tv.o nv17_tv.o nv17_tv_modes.o \
              nv04_crtc.o nv04_display.o nv04_cursor.o nv04_fbcon.o \
-             nv17_gpio.o nv50_gpio.o
+             nv17_gpio.o nv50_gpio.o \
+             nv50_calc.o
 
 nouveau-$(CONFIG_DRM_NOUVEAU_DEBUG) += nouveau_debugfs.o
 nouveau-$(CONFIG_COMPAT) += nouveau_ioc32.o
diff --git a/drivers/gpu/drm/nouveau/nouveau_drv.h b/drivers/gpu/drm/nouveau/nouveau_drv.h
index 94d8dd27bde8..5b134438effe 100644
--- a/drivers/gpu/drm/nouveau/nouveau_drv.h
+++ b/drivers/gpu/drm/nouveau/nouveau_drv.h
@@ -1170,6 +1170,12 @@ int nv17_gpio_set(struct drm_device *dev, enum dcb_gpio_tag tag, int state);
 int nv50_gpio_get(struct drm_device *dev, enum dcb_gpio_tag tag);
 int nv50_gpio_set(struct drm_device *dev, enum dcb_gpio_tag tag, int state);
 
+/* nv50_calc. */
+int nv50_calc_pll(struct drm_device *, struct pll_lims *, int clk,
+                  int *N1, int *M1, int *N2, int *M2, int *P);
+int nv50_calc_pll2(struct drm_device *, struct pll_lims *,
+                   int clk, int *N, int *fN, int *M, int *P);
+
 #ifndef ioread32_native
 #ifdef __BIG_ENDIAN
 #define ioread16_native ioread16be
diff --git a/drivers/gpu/drm/nouveau/nv50_calc.c b/drivers/gpu/drm/nouveau/nv50_calc.c
new file mode 100644
index 000000000000..2cdc2bfe7179
--- /dev/null
+++ b/drivers/gpu/drm/nouveau/nv50_calc.c
@@ -0,0 +1,87 @@
+/*
+ * Copyright 2010 Red Hat Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Authors: Ben Skeggs
+ */
+
+#include "drmP.h"
+#include "drm_fixed.h"
+#include "nouveau_drv.h"
+#include "nouveau_hw.h"
+
+int
+nv50_calc_pll(struct drm_device *dev, struct pll_lims *pll, int clk,
+              int *N1, int *M1, int *N2, int *M2, int *P)
+{
+        struct nouveau_pll_vals pll_vals;
+        int ret;
+
+        ret = nouveau_calc_pll_mnp(dev, pll, clk, &pll_vals);
+        if (ret <= 0)
+                return ret;
+
+        *N1 = pll_vals.N1;
+        *M1 = pll_vals.M1;
+        *N2 = pll_vals.N2;
+        *M2 = pll_vals.M2;
+        *P = pll_vals.log2P;
+        return ret;
+}
+
+int
+nv50_calc_pll2(struct drm_device *dev, struct pll_lims *pll, int clk,
+               int *N, int *fN, int *M, int *P)
+{
+        fixed20_12 fb_div, a, b;
+
+        *P = pll->vco1.maxfreq / clk;
+        if (*P > pll->max_p)
+                *P = pll->max_p;
+        if (*P < pll->min_p)
+                *P = pll->min_p;
+
+        /* *M = ceil(refclk / pll->vco.max_inputfreq); */
+        a.full = dfixed_const(pll->refclk);
+        b.full = dfixed_const(pll->vco1.max_inputfreq);
+        a.full = dfixed_div(a, b);
+        a.full = dfixed_ceil(a);
+        *M = dfixed_trunc(a);
+
+        /* fb_div = (vco * *M) / refclk; */
+        fb_div.full = dfixed_const(clk * *P);
+        fb_div.full = dfixed_mul(fb_div, a);
+        a.full = dfixed_const(pll->refclk);
+        fb_div.full = dfixed_div(fb_div, a);
+
+        /* *N = floor(fb_div); */
+        a.full = dfixed_floor(fb_div);
+        *N = dfixed_trunc(fb_div);
+
+        /* *fN = (fmod(fb_div, 1.0) * 8192) - 4096; */
+        b.full = dfixed_const(8192);
+        a.full = dfixed_mul(a, b);
+        fb_div.full = dfixed_mul(fb_div, b);
+        fb_div.full = fb_div.full - a.full;
+        *fN = dfixed_trunc(fb_div) - 4096;
+        *fN &= 0xffff;
+
+        return clk;
+}
diff --git a/drivers/gpu/drm/nouveau/nv50_crtc.c b/drivers/gpu/drm/nouveau/nv50_crtc.c
index 41fe8aec0a12..b4e4a3b05eae 100644
--- a/drivers/gpu/drm/nouveau/nv50_crtc.c
+++ b/drivers/gpu/drm/nouveau/nv50_crtc.c
@@ -264,38 +264,40 @@ nv50_crtc_set_scale(struct nouveau_crtc *nv_crtc, int scaling_mode, bool update)
 int
 nv50_crtc_set_clock(struct drm_device *dev, int head, int pclk)
 {
-        uint32_t pll_reg = NV50_PDISPLAY_CRTC_CLK_CTRL1(head);
-        struct nouveau_pll_vals pll;
-        struct pll_lims limits;
+        uint32_t reg = NV50_PDISPLAY_CRTC_CLK_CTRL1(head);
+        struct pll_lims pll;
         uint32_t reg1, reg2;
-        int ret;
+        int ret, N1, M1, N2, M2, P;
 
-        ret = get_pll_limits(dev, pll_reg, &limits);
+        ret = get_pll_limits(dev, reg, &pll);
         if (ret)
                 return ret;
 
-        ret = nouveau_calc_pll_mnp(dev, &limits, pclk, &pll);
-        if (ret <= 0)
-                return ret;
+        if (pll.vco2.maxfreq) {
+                ret = nv50_calc_pll(dev, &pll, pclk, &N1, &M1, &N2, &M2, &P);
+                if (ret <= 0)
+                        return 0;
 
-        if (limits.vco2.maxfreq) {
                 NV_DEBUG(dev, "pclk %d out %d NM1 %d %d NM2 %d %d P %d\n",
-                         pclk, ret, pll.N1, pll.M1, pll.N2, pll.M2, pll.log2P);
-
-                reg1 = nv_rd32(dev, pll_reg + 4) & 0xff00ff00;
-                reg2 = nv_rd32(dev, pll_reg + 8) & 0x8000ff00;
-                nv_wr32(dev, pll_reg, 0x10000611);
-                nv_wr32(dev, pll_reg + 4, reg1 | (pll.M1 << 16) | pll.N1);
-                nv_wr32(dev, pll_reg + 8,
-                        reg2 | (pll.log2P << 28) | (pll.M2 << 16) | pll.N2);
+                         pclk, ret, N1, M1, N2, M2, P);
+
+                reg1 = nv_rd32(dev, reg + 4) & 0xff00ff00;
+                reg2 = nv_rd32(dev, reg + 8) & 0x8000ff00;
+                nv_wr32(dev, reg, 0x10000611);
+                nv_wr32(dev, reg + 4, reg1 | (M1 << 16) | N1);
+                nv_wr32(dev, reg + 8, reg2 | (P << 28) | (M2 << 16) | N2);
         } else {
-                NV_DEBUG(dev, "pclk %d out %d NM %d %d P %d\n",
-                         pclk, ret, pll.N1, pll.M1, pll.log2P);
+                ret = nv50_calc_pll2(dev, &pll, pclk, &N1, &N2, &M1, &P);
+                if (ret <= 0)
+                        return 0;
+
+                NV_DEBUG(dev, "pclk %d out %d N %d fN 0x%04x M %d P %d\n",
+                         pclk, ret, N1, N2, M1, P);
 
-                reg1 = nv_rd32(dev, pll_reg + 4) & 0xffc00000;
-                nv_wr32(dev, pll_reg, 0x50000610);
-                nv_wr32(dev, pll_reg + 4, reg1 |
-                        (pll.log2P << 16) | (pll.M1 << 8) | pll.N1);
+                reg1 = nv_rd32(dev, reg + 4) & 0xffc00000;
+                nv_wr32(dev, reg, 0x50000610);
+                nv_wr32(dev, reg + 4, reg1 | (P << 16) | (M1 << 8) | N1);
+                nv_wr32(dev, reg + 8, N2);
         }
 
         return 0;