diff options
Diffstat (limited to 'arch/arm/mach-omap2/clkt2xxx_dpllcore.c')
| -rw-r--r-- | arch/arm/mach-omap2/clkt2xxx_dpllcore.c | 196 |
1 files changed, 196 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 000000000..e8d417309 --- /dev/null +++ b/arch/arm/mach-omap2/clkt2xxx_dpllcore.c @@ -0,0 +1,196 @@ +/* + * 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 "clock.h" +#include "clock2xxx.h" +#include "opp2xxx.h" +#include "cm2xxx.h" +#include "cm-regbits-24xx.h" +#include "sdrc.h" +#include "sram.h" + +/* #define DOWN_VARIABLE_DPLL 1 */ /* Experimental */ + +/* + * dpll_core_ck: pointer to the combined dpll_ck + core_ck on OMAP2xxx + * (currently defined as "dpll_ck" in the OMAP2xxx clock tree). Set + * during dpll_ck init and used later by omap2xxx_clk_get_core_rate(). + */ +static struct clk_hw_omap *dpll_core_ck; + +/** + * omap2xxx_clk_get_core_rate - return the CORE_CLK rate + * + * 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(void) +{ + long long core_clk; + u32 v; + + WARN_ON(!dpll_core_ck); + + core_clk = omap2_get_dpll_rate(dpll_core_ck); + + v = omap2xxx_cm_get_core_clk_src(); + + 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 = omap2xxx_cm_get_core_clk_src(); + + 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_hw *hw, + unsigned long parent_rate) +{ + return omap2xxx_clk_get_core_rate(); +} + +int omap2_reprogram_dpllcore(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct clk_hw_omap *clk = to_clk_hw_omap(hw); + 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(); + mult = omap2xxx_cm_get_core_clk_src(); + + 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 = + omap_clk_ll_ops.clk_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 = omap2xxx_cm_get_core_pll_config(); + 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; +} + +/** + * omap2xxx_clkt_dpllcore_init - clk init function for dpll_ck + * @clk: struct clk *dpll_ck + * + * Store a local copy of @clk in dpll_core_ck so other code can query + * the core rate without having to clk_get(), which can sleep. Must + * only be called once. No return value. XXX If the clock + * registration process is ever changed such that dpll_ck is no longer + * statically defined, this code may need to change to increment some + * kind of use count on dpll_ck. + */ +void omap2xxx_clkt_dpllcore_init(struct clk_hw *hw) +{ + WARN(dpll_core_ck, "dpll_core_ck already set - should never happen"); + dpll_core_ck = to_clk_hw_omap(hw); +} |