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Diffstat (limited to 'arch/mips/pic32/pic32mzda/early_clk.c')
-rw-r--r--arch/mips/pic32/pic32mzda/early_clk.c106
1 files changed, 106 insertions, 0 deletions
diff --git a/arch/mips/pic32/pic32mzda/early_clk.c b/arch/mips/pic32/pic32mzda/early_clk.c
new file mode 100644
index 000000000000..96c090e9d637
--- /dev/null
+++ b/arch/mips/pic32/pic32mzda/early_clk.c
@@ -0,0 +1,106 @@
+/*
+ * Joshua Henderson <joshua.henderson@microchip.com>
+ * Copyright (C) 2015 Microchip Technology Inc. All rights reserved.
+ *
+ * This program is free software; you can distribute it and/or modify it
+ * under the terms of the GNU General Public License (Version 2) as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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.
+ */
+#include <asm/mach-pic32/pic32.h>
+
+#include "pic32mzda.h"
+
+/* Oscillators, PLL & clocks */
+#define ICLK_MASK 0x00000080
+#define PLLDIV_MASK 0x00000007
+#define CUROSC_MASK 0x00000007
+#define PLLMUL_MASK 0x0000007F
+#define PB_MASK 0x00000007
+#define FRC1 0
+#define FRC2 7
+#define SPLL 1
+#define POSC 2
+#define FRC_CLK 8000000
+
+#define PIC32_POSC_FREQ 24000000
+
+#define OSCCON 0x0000
+#define SPLLCON 0x0020
+#define PB1DIV 0x0140
+
+u32 pic32_get_sysclk(void)
+{
+ u32 osc_freq = 0;
+ u32 pllclk;
+ u32 frcdivn;
+ u32 osccon;
+ u32 spllcon;
+ int curr_osc;
+
+ u32 plliclk;
+ u32 pllidiv;
+ u32 pllodiv;
+ u32 pllmult;
+ u32 frcdiv;
+
+ void __iomem *osc_base = ioremap(PIC32_BASE_OSC, 0x200);
+
+ osccon = __raw_readl(osc_base + OSCCON);
+ spllcon = __raw_readl(osc_base + SPLLCON);
+
+ plliclk = (spllcon & ICLK_MASK);
+ pllidiv = ((spllcon >> 8) & PLLDIV_MASK) + 1;
+ pllodiv = ((spllcon >> 24) & PLLDIV_MASK);
+ pllmult = ((spllcon >> 16) & PLLMUL_MASK) + 1;
+ frcdiv = ((osccon >> 24) & PLLDIV_MASK);
+
+ pllclk = plliclk ? FRC_CLK : PIC32_POSC_FREQ;
+ frcdivn = ((1 << frcdiv) + 1) + (128 * (frcdiv == 7));
+
+ if (pllodiv < 2)
+ pllodiv = 2;
+ else if (pllodiv < 5)
+ pllodiv = (1 << pllodiv);
+ else
+ pllodiv = 32;
+
+ curr_osc = (int)((osccon >> 12) & CUROSC_MASK);
+
+ switch (curr_osc) {
+ case FRC1:
+ case FRC2:
+ osc_freq = FRC_CLK / frcdivn;
+ break;
+ case SPLL:
+ osc_freq = ((pllclk / pllidiv) * pllmult) / pllodiv;
+ break;
+ case POSC:
+ osc_freq = PIC32_POSC_FREQ;
+ break;
+ default:
+ break;
+ }
+
+ iounmap(osc_base);
+
+ return osc_freq;
+}
+
+u32 pic32_get_pbclk(int bus)
+{
+ u32 clk_freq;
+ void __iomem *osc_base = ioremap(PIC32_BASE_OSC, 0x200);
+ u32 pbxdiv = PB1DIV + ((bus - 1) * 0x10);
+ u32 pbdiv = (__raw_readl(osc_base + pbxdiv) & PB_MASK) + 1;
+
+ iounmap(osc_base);
+
+ clk_freq = pic32_get_sysclk();
+
+ return clk_freq / pbdiv;
+}