diff options
Diffstat (limited to 'arch/arm/mach-omap2/clkt2xxx_dpllcore.c')
| -rw-r--r-- | arch/arm/mach-omap2/clkt2xxx_dpllcore.c | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/clkt2xxx_dpllcore.c b/arch/arm/mach-omap2/clkt2xxx_dpllcore.c new file mode 100644 index 00000000..4ae43922 --- /dev/null +++ b/arch/arm/mach-omap2/clkt2xxx_dpllcore.c @@ -0,0 +1,173 @@ +/* + * DPLL + CORE_CLK composite clock functions + * + * Copyright (C) 2005-2008 Texas Instruments, Inc. + * Copyright (C) 2004-2010 Nokia Corporation + * + * Contacts: + * Richard Woodruff <r-woodruff2@ti.com> + * Paul Walmsley + * + * Based on earlier work by Tuukka Tikkanen, Tony Lindgren, + * Gordon McNutt and RidgeRun, Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * XXX The DPLL and CORE clocks should be split into two separate clock + * types. + */ +#undef DEBUG + +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/clk.h> +#include <linux/io.h> + +#include <plat/clock.h> +#include <plat/sram.h> +#include <plat/sdrc.h> + +#include "clock.h" +#include "clock2xxx.h" +#include "opp2xxx.h" +#include "cm2xxx_3xxx.h" +#include "cm-regbits-24xx.h" + +/* #define DOWN_VARIABLE_DPLL 1 */ /* Experimental */ + +/** + * omap2xxx_clk_get_core_rate - return the CORE_CLK rate + * @clk: pointer to the combined dpll_ck + core_ck (currently "dpll_ck") + * + * Returns the CORE_CLK rate. CORE_CLK can have one of three rate + * sources on OMAP2xxx: the DPLL CLKOUT rate, DPLL CLKOUTX2, or 32KHz + * (the latter is unusual). This currently should be called with + * struct clk *dpll_ck, which is a composite clock of dpll_ck and + * core_ck. + */ +unsigned long omap2xxx_clk_get_core_rate(struct clk *clk) +{ + long long core_clk; + u32 v; + + core_clk = omap2_get_dpll_rate(clk); + + v = omap2_cm_read_mod_reg(PLL_MOD, CM_CLKSEL2); + v &= OMAP24XX_CORE_CLK_SRC_MASK; + + if (v == CORE_CLK_SRC_32K) + core_clk = 32768; + else + core_clk *= v; + + return core_clk; +} + +/* + * Uses the current prcm set to tell if a rate is valid. + * You can go slower, but not faster within a given rate set. + */ +static long omap2_dpllcore_round_rate(unsigned long target_rate) +{ + u32 high, low, core_clk_src; + + core_clk_src = omap2_cm_read_mod_reg(PLL_MOD, CM_CLKSEL2); + core_clk_src &= OMAP24XX_CORE_CLK_SRC_MASK; + + if (core_clk_src == CORE_CLK_SRC_DPLL) { /* DPLL clockout */ + high = curr_prcm_set->dpll_speed * 2; + low = curr_prcm_set->dpll_speed; + } else { /* DPLL clockout x 2 */ + high = curr_prcm_set->dpll_speed; + low = curr_prcm_set->dpll_speed / 2; + } + +#ifdef DOWN_VARIABLE_DPLL + if (target_rate > high) + return high; + else + return target_rate; +#else + if (target_rate > low) + return high; + else + return low; +#endif + +} + +unsigned long omap2_dpllcore_recalc(struct clk *clk) +{ + return omap2xxx_clk_get_core_rate(clk); +} + +int omap2_reprogram_dpllcore(struct clk *clk, unsigned long rate) +{ + u32 cur_rate, low, mult, div, valid_rate, done_rate; + u32 bypass = 0; + struct prcm_config tmpset; + const struct dpll_data *dd; + + cur_rate = omap2xxx_clk_get_core_rate(dclk); + mult = omap2_cm_read_mod_reg(PLL_MOD, CM_CLKSEL2); + mult &= OMAP24XX_CORE_CLK_SRC_MASK; + + if ((rate == (cur_rate / 2)) && (mult == 2)) { + omap2xxx_sdrc_reprogram(CORE_CLK_SRC_DPLL, 1); + } else if ((rate == (cur_rate * 2)) && (mult == 1)) { + omap2xxx_sdrc_reprogram(CORE_CLK_SRC_DPLL_X2, 1); + } else if (rate != cur_rate) { + valid_rate = omap2_dpllcore_round_rate(rate); + if (valid_rate != rate) + return -EINVAL; + + if (mult == 1) + low = curr_prcm_set->dpll_speed; + else + low = curr_prcm_set->dpll_speed / 2; + + dd = clk->dpll_data; + if (!dd) + return -EINVAL; + + tmpset.cm_clksel1_pll = __raw_readl(dd->mult_div1_reg); + tmpset.cm_clksel1_pll &= ~(dd->mult_mask | + dd->div1_mask); + div = ((curr_prcm_set->xtal_speed / 1000000) - 1); + tmpset.cm_clksel2_pll = omap2_cm_read_mod_reg(PLL_MOD, CM_CLKSEL2); + tmpset.cm_clksel2_pll &= ~OMAP24XX_CORE_CLK_SRC_MASK; + if (rate > low) { + tmpset.cm_clksel2_pll |= CORE_CLK_SRC_DPLL_X2; + mult = ((rate / 2) / 1000000); + done_rate = CORE_CLK_SRC_DPLL_X2; + } else { + tmpset.cm_clksel2_pll |= CORE_CLK_SRC_DPLL; + mult = (rate / 1000000); + done_rate = CORE_CLK_SRC_DPLL; + } + tmpset.cm_clksel1_pll |= (div << __ffs(dd->mult_mask)); + tmpset.cm_clksel1_pll |= (mult << __ffs(dd->div1_mask)); + + /* Worst case */ + tmpset.base_sdrc_rfr = SDRC_RFR_CTRL_BYPASS; + + if (rate == curr_prcm_set->xtal_speed) /* If asking for 1-1 */ + bypass = 1; + + /* For omap2xxx_sdrc_init_params() */ + omap2xxx_sdrc_reprogram(CORE_CLK_SRC_DPLL_X2, 1); + + /* Force dll lock mode */ + omap2_set_prcm(tmpset.cm_clksel1_pll, tmpset.base_sdrc_rfr, + bypass); + + /* Errata: ret dll entry state */ + omap2xxx_sdrc_init_params(omap2xxx_sdrc_dll_is_unlocked()); + omap2xxx_sdrc_reprogram(done_rate, 0); + } + + return 0; +} + |