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path: root/drivers/gpu/drm/nouveau/nv50_calc.c
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Diffstat (limited to 'drivers/gpu/drm/nouveau/nv50_calc.c')
-rw-r--r--drivers/gpu/drm/nouveau/nv50_calc.c97
1 files changed, 97 insertions, 0 deletions
diff --git a/drivers/gpu/drm/nouveau/nv50_calc.c b/drivers/gpu/drm/nouveau/nv50_calc.c
new file mode 100644
index 00000000..8cf63a8b
--- /dev/null
+++ b/drivers/gpu/drm/nouveau/nv50_calc.c
@@ -0,0 +1,97 @@
+/*
+ * 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 "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
+nva3_calc_pll(struct drm_device *dev, struct pll_lims *pll, int clk,
+ int *pN, int *pfN, int *pM, int *P)
+{
+ u32 best_err = ~0, err;
+ int M, lM, hM, N, fN;
+
+ *P = pll->vco1.maxfreq / clk;
+ if (*P > pll->max_p)
+ *P = pll->max_p;
+ if (*P < pll->min_p)
+ *P = pll->min_p;
+
+ lM = (pll->refclk + pll->vco1.max_inputfreq) / pll->vco1.max_inputfreq;
+ lM = max(lM, (int)pll->vco1.min_m);
+ hM = (pll->refclk + pll->vco1.min_inputfreq) / pll->vco1.min_inputfreq;
+ hM = min(hM, (int)pll->vco1.max_m);
+
+ for (M = lM; M <= hM; M++) {
+ u32 tmp = clk * *P * M;
+ N = tmp / pll->refclk;
+ fN = tmp % pll->refclk;
+ if (!pfN && fN >= pll->refclk / 2)
+ N++;
+
+ if (N < pll->vco1.min_n)
+ continue;
+ if (N > pll->vco1.max_n)
+ break;
+
+ err = abs(clk - (pll->refclk * N / M / *P));
+ if (err < best_err) {
+ best_err = err;
+ *pN = N;
+ *pM = M;
+ }
+
+ if (pfN) {
+ *pfN = (((fN << 13) / pll->refclk) - 4096) & 0xffff;
+ return clk;
+ }
+ }
+
+ if (unlikely(best_err == ~0)) {
+ NV_ERROR(dev, "unable to find matching pll values\n");
+ return -EINVAL;
+ }
+
+ return pll->refclk * *pN / *pM / *P;
+}