AT91SAM7: add compile time pll constant computation.

git-svn-id: https://src.develer.com/svnoss/bertos/trunk@3384 38d2e660-2303-0410-9eaa-f027e97ec537

diff --git a/bertos/cpu/arm/hw/pll_at91.h b/bertos/cpu/arm/hw/pll_at91.h
new file mode 100644 (file)
index 0000000..50f4a0c
--- /dev/null
+++ b/bertos/cpu/arm/hw/pll_at91.h
@@ -0,0 +1,153 @@
+/**
+ * \file
+ * <!--
+ * This file is part of BeRTOS.
+ *
+ * Bertos is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * As a special exception, you may use this file as part of a free software
+ * library without restriction.  Specifically, if other files instantiate
+ * templates or use macros or inline functions from this file, or you compile
+ * this file and link it with other files to produce an executable, this
+ * file does not by itself cause the resulting executable to be covered by
+ * the GNU General Public License.  This exception does not however
+ * invalidate any other reasons why the executable file might be covered by
+ * the GNU General Public License.
+ *
+ * Copyright 2010 Develer S.r.l. (http://www.develer.com/)
+ *
+ * -->
+ *
+ *
+ * \author Giovanni Bajo <rasky@develer.com>
+ *
+ * \brief AT91SAM7S256 CRT.
+ */
+
+#include <io/arm.h>
+#include <cfg/macros.h>
+
+#if 1
+// Versione completamente unrollata
+
+#define CREATE_PLL_STEP(xtal, cpufreq)
+
+#define PLL_STEP(xtal, cpufreq, d, k) \
+    do { \
+        uint32_t m = (((cpufreq * (1LL << k) * (d))  + (xtal / 2)) / xtal) - 1; \
+        if (m < 2048) \
+        { \
+            uint32_t pll = (d != 0) ? (xtal * (m + 1)) / (d) : 0; \
+            if (80000000 <= pll && pll <= 160000000) \
+            { \
+               uint32_t err = ABS((int32_t)((pll >> k) - cpufreq)); \
+                if (err < best_err) \
+                { \
+                    best_err=err; best_m=m; best_k=k; best_d=d; \
+                } \
+            } \
+        } \
+    } while (0)
+
+#else
+
+// Versione con funzione nestata (GCC only)
+// Tempo di compilazione più rapido
+
+#define CREATE_PLL_STEP(xtal, cpufreq) \
+    void __attribute__((always_inline)) PLL_STEP(int u1, int u2, int32_t d, long long k)  \
+    { \
+        (void)u1; (void)u2; \
+        uint32_t m = ((((cpufreq * (1LL << k) * (d))  + (xtal / 2)) / xtal) - 1; \
+        if (m < 2048) \
+        { \
+            uint32_t pll = (xtal * (m + 1)) / (d); \
+            if (80000000UL <= pll && pll <= 160000000UL) \
+            { \
+                uint32_t err = ABS((int32_t)((pll >> k) - cpufreq)); \
+                if (err < best_err) \
+                { \
+                    best_err=err; best_m=m; best_k=k; best_d=d; \
+                } \
+            } \
+        } \
+    }
+
+#endif
+
+#define PLL_MACRO_STEP(xtal, cpufreq, d) \
+    do { \
+        if ((d) > 0 && (d) <= 255 && \
+            (d) <= xtal / 1000000 && (d) >= xtal / 32000000) \
+        { \
+            PLL_STEP(xtal, cpufreq, d, 0); \
+            PLL_STEP(xtal, cpufreq, d, 1); \
+            PLL_STEP(xtal, cpufreq, d, 2); \
+            PLL_STEP(xtal, cpufreq, d, 3); \
+            PLL_STEP(xtal, cpufreq, d, 4); \
+            PLL_STEP(xtal, cpufreq, d, 5); \
+            PLL_STEP(xtal, cpufreq, d, 6); \
+        } \
+    } while (0)
+
+#define PLL_ITERATION_4(xtal, cpufreq, d) \
+    PLL_MACRO_STEP(xtal, cpufreq, d)
+
+#define PLL_ITERATION_3(xtal, cpufreq, d) \
+    PLL_ITERATION_4(xtal, cpufreq, (d)*4+0); \
+    PLL_ITERATION_4(xtal, cpufreq, (d)*4+1); \
+    PLL_ITERATION_4(xtal, cpufreq, (d)*4+2); \
+    PLL_ITERATION_4(xtal, cpufreq, (d)*4+3);
+
+#define PLL_ITERATION_2(xtal, cpufreq, d) \
+    PLL_ITERATION_3(xtal, cpufreq, (d)*4+0); \
+    PLL_ITERATION_3(xtal, cpufreq, (d)*4+1); \
+    PLL_ITERATION_3(xtal, cpufreq, (d)*4+2); \
+    PLL_ITERATION_3(xtal, cpufreq, (d)*4+3);
+
+#define PLL_ITERATION_1(xtal, cpufreq, d) \
+    PLL_ITERATION_2(xtal, cpufreq, (d)*4+0); \
+    PLL_ITERATION_2(xtal, cpufreq, (d)*4+1); \
+    PLL_ITERATION_2(xtal, cpufreq, (d)*4+2); \
+    PLL_ITERATION_2(xtal, cpufreq, (d)*4+3);
+
+#define PLL_ITERATION(xtal, cpufreq) \
+    PLL_ITERATION_1(xtal, cpufreq, 0); \
+    PLL_ITERATION_1(xtal, cpufreq, 1); \
+    PLL_ITERATION_1(xtal, cpufreq, 2); \
+    PLL_ITERATION_1(xtal, cpufreq, 3)
+
+#define PLL_CALC(xtal, cpufreq, m, d, k) do \
+    { \
+        uint32_t best_err=cpufreq, best_m, best_k, best_d; \
+        CREATE_PLL_STEP(xtal, cpufreq) \
+        PLL_ITERATION(xtal, cpufreq); \
+        *(m)=best_m; *(d)=best_d; *(k)=best_k; \
+    } while (0)
+
+#if 0
+int main(int argc, char *argv[])
+{
+    int32_t m, d, k;
+    PLL_CALC(18420000, 48023000, &m, &d, &k);
+
+    if (__builtin_constant_p(m) && __builtin_constant_p(k) && __builtin_constant_p(d))
+        printf("SUCCESS -- compile time evaluation\n");
+    else
+        printf("FAILURE -- run time evaluation\n");
+
+    printf("M:%d D:%d K:%d\n", m, d, k);
+}
+#endif