2 * OMAP34xx M2 divider clock code
4 * Copyright (C) 2007-2008 Texas Instruments, Inc.
5 * Copyright (C) 2007-2010 Nokia Corporation
10 * Parts of this code are based on code written by
11 * Richard Woodruff, Tony Lindgren, Tuukka Tikkanen, Karthik Dasu
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License version 2 as
15 * published by the Free Software Foundation.
19 #include <linux/kernel.h>
20 #include <linux/errno.h>
21 #include <linux/clk.h>
25 #include "clock3xxx.h"
29 #define CYCLES_PER_MHZ 1000000
31 struct clk *sdrc_ick_p, *arm_fck_p;
34 * CORE DPLL (DPLL3) M2 divider rate programming functions
36 * These call into SRAM code to do the actual CM writes, since the SDRAM
37 * is clocked from DPLL3.
41 * omap3_core_dpll_m2_set_rate - set CORE DPLL M2 divider
42 * @clk: struct clk * of DPLL to set
43 * @rate: rounded target rate
45 * Program the DPLL M2 divider with the rounded target rate. Returns
46 * -EINVAL upon error, or 0 upon success.
48 int omap3_core_dpll_m2_set_rate(struct clk_hw *hw, unsigned long rate,
49 unsigned long parent_rate)
51 struct clk_hw_omap *clk = to_clk_hw_omap(hw);
55 unsigned long validrate, sdrcrate, _mpurate;
56 struct omap_sdrc_params *sdrc_cs0;
57 struct omap_sdrc_params *sdrc_cs1;
59 unsigned long clkrate;
64 new_div = DIV_ROUND_UP(parent_rate, rate);
65 validrate = parent_rate / new_div;
67 if (validrate != rate)
70 sdrcrate = clk_get_rate(sdrc_ick_p);
71 clkrate = clk_hw_get_rate(hw);
73 sdrcrate <<= ((rate / clkrate) >> 1);
75 sdrcrate >>= ((clkrate / rate) >> 1);
77 ret = omap2_sdrc_get_params(sdrcrate, &sdrc_cs0, &sdrc_cs1);
81 if (sdrcrate < MIN_SDRC_DLL_LOCK_FREQ) {
82 pr_debug("clock: will unlock SDRC DLL\n");
87 * XXX This only needs to be done when the CPU frequency changes
89 _mpurate = clk_get_rate(arm_fck_p) / CYCLES_PER_MHZ;
90 c = (_mpurate << SDRC_MPURATE_SCALE) >> SDRC_MPURATE_BASE_SHIFT;
91 c += 1; /* for safety */
92 c *= SDRC_MPURATE_LOOPS;
93 c >>= SDRC_MPURATE_SCALE;
97 pr_debug("clock: changing CORE DPLL rate from %lu to %lu\n",
99 pr_debug("clock: SDRC CS0 timing params used: RFR %08x CTRLA %08x CTRLB %08x MR %08x\n",
100 sdrc_cs0->rfr_ctrl, sdrc_cs0->actim_ctrla,
101 sdrc_cs0->actim_ctrlb, sdrc_cs0->mr);
103 pr_debug("clock: SDRC CS1 timing params used: RFR %08x CTRLA %08x CTRLB %08x MR %08x\n",
104 sdrc_cs1->rfr_ctrl, sdrc_cs1->actim_ctrla,
105 sdrc_cs1->actim_ctrlb, sdrc_cs1->mr);
108 omap3_configure_core_dpll(
109 new_div, unlock_dll, c, rate > clkrate,
110 sdrc_cs0->rfr_ctrl, sdrc_cs0->actim_ctrla,
111 sdrc_cs0->actim_ctrlb, sdrc_cs0->mr,
112 sdrc_cs1->rfr_ctrl, sdrc_cs1->actim_ctrla,
113 sdrc_cs1->actim_ctrlb, sdrc_cs1->mr);
115 omap3_configure_core_dpll(
116 new_div, unlock_dll, c, rate > clkrate,
117 sdrc_cs0->rfr_ctrl, sdrc_cs0->actim_ctrla,
118 sdrc_cs0->actim_ctrlb, sdrc_cs0->mr,