+/*
+ * CPU clock
+ * Fout = (m * Fin) / (p * 2^s)
+ * m = MDIV+8, p = PDIV+2, s = SDIV
+ *
+ * m = (Fout * p * 2^s) / Fin
+ */
+
+#define SYS_CLK_FREQ 7372800
+
+static void gp2x_set_cpuclk_(unsigned int mhz)
+{
+ unsigned int mdiv, pdiv, sdiv = 0;
+ unsigned int v;
+ int i;
+
+ pdiv = 3;
+ mdiv = (mhz * pdiv * 1000000) / SYS_CLK_FREQ;
+ if (mdiv & ~0xff) {
+ fprintf(stderr, "invalid cpuclk MHz: %u\n", mhz);
+ return;
+ }
+ v = ((mdiv-8)<<8) | ((pdiv-2)<<2) | sdiv;
+ gp2x_memregs[0x910>>1] = v;
+
+ for (i = 0; i < 10000; i++)
+ if (!(gp2x_memregs[0x902>>1] & 1))
+ break;
+
+ cpuclk_was_changed = 1;
+}
+
+/* RAM timings */
+#define TIMING_CHECK(t, adj, mask) \
+ t += adj; \
+ if (t & ~mask) \
+ goto bad
+
+static void set_ram_timing_vals(int tCAS, int tRC, int tRAS, int tWR, int tMRD, int tRFC, int tRP, int tRCD)
+{
+ int i;
+ TIMING_CHECK(tCAS, -2, 0x1);
+ TIMING_CHECK(tRC, -1, 0xf);
+ TIMING_CHECK(tRAS, -1, 0xf);
+ TIMING_CHECK(tWR, -1, 0xf);
+ TIMING_CHECK(tMRD, -1, 0xf);
+ TIMING_CHECK(tRFC, -1, 0xf);
+ TIMING_CHECK(tRP, -1, 0xf);
+ TIMING_CHECK(tRCD, -1, 0xf);
+
+ /* get spend_cycles() into cache */
+ spend_cycles(1);
+
+ gp2x_memregs[0x3802>>1] = ((tMRD & 0xF) << 12) | ((tRFC & 0xF) << 8) | ((tRP & 0xF) << 4) | (tRCD & 0xF);
+ gp2x_memregs[0x3804>>1] = 0x8000 | ((tCAS & 1) << 12) | ((tRC & 0xF) << 8) | ((tRAS & 0xF) << 4) | (tWR & 0xF);
+
+ /* be sure we don't access the mem while it's being reprogrammed */
+ spend_cycles(128*1024);
+ for (i = 0; i < 8*1024; i++)
+ if (!(gp2x_memregs[0x3804>>1] & 0x8000))
+ break;
+
+ printf("RAM timings set.\n");
+ return;
+bad:
+ fprintf(stderr, "RAM timings invalid.\n");
+}
+
+static void set_ram_timings_(void)
+{
+ /* craigix: --cas 2 --trc 6 --tras 4 --twr 1 --tmrd 1 --trfc 1 --trp 2 --trcd 2 */
+ set_ram_timing_vals(2, 6, 4, 1, 1, 1, 2, 2);
+}
+
+static void unset_ram_timings_(void)
+{
+ gp2x_memregs[0x3802>>1] = memtimex_old[0];
+ gp2x_memregs[0x3804>>1] = memtimex_old[1] | 0x8000;
+ printf("RAM timings reset to startup values.\n");
+}
+
+/* LCD refresh */
+typedef struct
+{
+ unsigned short reg, valmask, val;
+}
+reg_setting;
+
+/* 120.00 97/0/2/7|25/ 7/ 7/11/37 */
+static const reg_setting lcd_rate_120[] =
+{
+ { 0x0914, 0xffff, (97<<8)|(0<<2)|2 }, /* UPLLSETVREG */
+ { 0x0924, 0xff00, (2<<14)|(7<<8) }, /* DISPCSETREG */
+ { 0x281A, 0x00ff, 25 }, /* .HSWID(T2) */
+ { 0x281C, 0x00ff, 7 }, /* .HSSTR(T8) */
+ { 0x281E, 0x00ff, 7 }, /* .HSEND(T7) */
+ { 0x2822, 0x01ff, 11 }, /* .VSEND (T9) */
+ { 0x2826, 0x0ff0, 37<<4 }, /* .DESTR(T3) */
+ { 0, 0, 0 }
+};
+
+/* 100.00 96/0/2/7|29/25/53/15/37 */
+static const reg_setting lcd_rate_100[] =
+{
+ { 0x0914, 0xffff, (96<<8)|(0<<2)|2 }, /* UPLLSETVREG */
+ { 0x0924, 0xff00, (2<<14)|(7<<8) }, /* DISPCSETREG */
+ { 0x281A, 0x00ff, 29 }, /* .HSWID(T2) */
+ { 0x281C, 0x00ff, 25 }, /* .HSSTR(T8) */
+ { 0x281E, 0x00ff, 53 }, /* .HSEND(T7) */
+ { 0x2822, 0x01ff, 15 }, /* .VSEND (T9) */
+ { 0x2826, 0x0ff0, 37<<4 }, /* .DESTR(T3) */
+ { 0, 0, 0 }
+};
+
+static reg_setting lcd_rate_defaults[] =
+{
+ { 0x0914, 0xffff, 0 },
+ { 0x0924, 0xff00, 0 },
+ { 0x281A, 0x00ff, 0 },
+ { 0x281C, 0x00ff, 0 },
+ { 0x281E, 0x00ff, 0 },
+ { 0x2822, 0x01ff, 0 },
+ { 0x2826, 0x0ff0, 0 },
+ { 0, 0, 0 }
+};
+
+static void get_reg_setting(reg_setting *set)
+{
+ for (; set->reg; set++)
+ {
+ unsigned short val = gp2x_memregs[set->reg >> 1];
+ val &= set->valmask;
+ set->val = val;
+ }
+}
+
+static void set_reg_setting(const reg_setting *set)
+{
+ for (; set->reg; set++)
+ {
+ unsigned short val = gp2x_memregs[set->reg >> 1];
+ val &= ~set->valmask;
+ val |= set->val;
+ gp2x_memregs[set->reg >> 1] = val;
+ }
+}
+
+static void set_lcd_custom_rate_(int is_pal)
+{
+ if (gp2x_memregs[0x2800>>1] & 0x100) // tv-out
+ return;
+
+ printf("setting custom LCD refresh (%d Hz)... ", is_pal ? 100 : 120);
+ fflush(stdout);
+
+ set_reg_setting(is_pal ? lcd_rate_100 : lcd_rate_120);
+ printf("done.\n");
+}
+
+static void unset_lcd_custom_rate_(void)
+{
+ printf("reset to prev LCD refresh.\n");
+ set_reg_setting(lcd_rate_defaults);
+}
+
+static void set_lcd_gamma_(int g100, int A_SNs_curve)
+{
+ float gamma = (float) g100 / 100;
+ int i;
+ gamma = 1 / gamma;
+
+ /* enable gamma */
+ gp2x_memregs[0x2880>>1] &= ~(1<<12);
+
+ gp2x_memregs[0x295C>>1] = 0;
+ for (i = 0; i < 256; i++)
+ {
+ unsigned char g;
+ unsigned short s;
+ const unsigned short grey50=143, grey75=177, grey25=97;
+ double blah;
+
+ if (A_SNs_curve)
+ {
+ // The next formula is all about gaussian interpolation
+ blah = (( -128 * exp(-powf((float) i/64.0f + 2.0f , 2.0f))) +
+ ( -64 * exp(-powf((float) i/64.0f + 1.0f , 2.0f))) +
+ (grey25 * exp(-powf((float) i/64.0f - 1.0f , 2.0f))) +
+ (grey50 * exp(-powf((float) i/64.0f - 2.0f , 2.0f))) +
+ (grey75 * exp(-powf((float) i/64.0f - 3.0f , 2.0f))) +
+ ( 256 * exp(-powf((float) i/64.0f - 4.0f , 2.0f))) +
+ ( 320 * exp(-powf((float) i/64.0f - 5.0f , 2.0f))) +
+ ( 384 * exp(-powf((float) i/64.0f - 6.0f , 2.0f)))) / 1.772637;
+ blah += 0.5;
+ }
+ else
+ {
+ blah = i;
+ }
+
+ g = (unsigned char)(255.0 * pow(blah/255.0, gamma));
+ //printf("%d : %d\n", i, g);
+ s = (g<<8) | g;
+ gp2x_memregs[0x295E>>1]= s;
+ gp2x_memregs[0x295E>>1]= g;
+ }
+
+ gamma_was_changed = 1;
+}
+
+static int gp2x_read_battery_(void)
+{
+ return -1; /* TODO? */
+}