/* * OMAP3/4 - specific DPLL control functions * * Copyright (C) 2009 Texas Instruments, Inc. * Copyright (C) 2009 Nokia Corporation * * Written by Paul Walmsley * Testing and integration fixes by Jouni Högander * * Parts of this code are based on code written by * Richard Woodruff, Tony Lindgren, Tuukka Tikkanen, Karthik Dasu * * 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. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "clock.h" #include "prm.h" #include "prm-regbits-34xx.h" #include "cm.h" #include "cm-regbits-34xx.h" /* CM_AUTOIDLE_PLL*.AUTO_* bit values */ #define DPLL_AUTOIDLE_DISABLE 0x0 #define DPLL_AUTOIDLE_LOW_POWER_STOP 0x1 #define MAX_DPLL_WAIT_TRIES 1000000 /* Private functions */ /* _omap3_dpll_write_clken - write clken_bits arg to a DPLL's enable bits */ static void _omap3_dpll_write_clken(struct clk *clk, u8 clken_bits) { const struct dpll_data *dd; u32 v; dd = clk->dpll_data; v = __raw_readl(dd->control_reg); v &= ~dd->enable_mask; v |= clken_bits << __ffs(dd->enable_mask); __raw_writel(v, dd->control_reg); } /* _omap3_wait_dpll_status: wait for a DPLL to enter a specific state */ static int _omap3_wait_dpll_status(struct clk *clk, u8 state) { const struct dpll_data *dd; int i = 0; int ret = -EINVAL; dd = clk->dpll_data; state <<= __ffs(dd->idlest_mask); while (((__raw_readl(dd->idlest_reg) & dd->idlest_mask) != state) && i < MAX_DPLL_WAIT_TRIES) { i++; udelay(1); } if (i == MAX_DPLL_WAIT_TRIES) { printk(KERN_ERR "clock: %s failed transition to '%s'\n", clk->name, (state) ? "locked" : "bypassed"); } else { pr_debug("clock: %s transition to '%s' in %d loops\n", clk->name, (state) ? "locked" : "bypassed", i); ret = 0; } return ret; } /* From 3430 TRM ES2 4.7.6.2 */ static u16 _omap3_dpll_compute_freqsel(struct clk *clk, u8 n) { unsigned long fint; u16 f = 0; fint = clk->dpll_data->clk_ref->rate / n; pr_debug("clock: fint is %lu\n", fint); if (fint >= 750000 && fint <= 1000000) f = 0x3; else if (fint > 1000000 && fint <= 1250000) f = 0x4; else if (fint > 1250000 && fint <= 1500000) f = 0x5; else if (fint > 1500000 && fint <= 1750000) f = 0x6; else if (fint > 1750000 && fint <= 2100000) f = 0x7; else if (fint > 7500000 && fint <= 10000000) f = 0xB; else if (fint > 10000000 && fint <= 12500000) f = 0xC; else if (fint > 12500000 && fint <= 15000000) f = 0xD; else if (fint > 15000000 && fint <= 17500000) f = 0xE; else if (fint > 17500000 && fint <= 21000000) f = 0xF; else pr_debug("clock: unknown freqsel setting for %d\n", n); return f; } /* * _omap3_noncore_dpll_lock - instruct a DPLL to lock and wait for readiness * @clk: pointer to a DPLL struct clk * * Instructs a non-CORE DPLL to lock. Waits for the DPLL to report * readiness before returning. Will save and restore the DPLL's * autoidle state across the enable, per the CDP code. If the DPLL * locked successfully, return 0; if the DPLL did not lock in the time * allotted, or DPLL3 was passed in, return -EINVAL. */ static int _omap3_noncore_dpll_lock(struct clk *clk) { u8 ai; int r; pr_debug("clock: locking DPLL %s\n", clk->name); ai = omap3_dpll_autoidle_read(clk); omap3_dpll_deny_idle(clk); _omap3_dpll_write_clken(clk, DPLL_LOCKED); r = _omap3_wait_dpll_status(clk, 1); if (ai) omap3_dpll_allow_idle(clk); return r; } /* * _omap3_noncore_dpll_bypass - instruct a DPLL to bypass and wait for readiness * @clk: pointer to a DPLL struct clk * * Instructs a non-CORE DPLL to enter low-power bypass mode. In * bypass mode, the DPLL's rate is set equal to its parent clock's * rate. Waits for the DPLL to report readiness before returning. * Will save and restore the DPLL's autoidle state across the enable, * per the CDP code. If the DPLL entered bypass mode successfully, * return 0; if the DPLL did not enter bypass in the time allotted, or * DPLL3 was passed in, or the DPLL does not support low-power bypass, * return -EINVAL. */ static int _omap3_noncore_dpll_bypass(struct clk *clk) { int r; u8 ai; if (!(clk->dpll_data->modes & (1 << DPLL_LOW_POWER_BYPASS))) return -EINVAL; pr_debug("clock: configuring DPLL %s for low-power bypass\n", clk->name); ai = omap3_dpll_autoidle_read(clk); _omap3_dpll_write_clken(clk, DPLL_LOW_POWER_BYPASS); r = _omap3_wait_dpll_status(clk, 0); if (ai) omap3_dpll_allow_idle(clk); else omap3_dpll_deny_idle(clk); return r; } /* * _omap3_noncore_dpll_stop - instruct a DPLL to stop * @clk: pointer to a DPLL struct clk * * Instructs a non-CORE DPLL to enter low-power stop. Will save and * restore the DPLL's autoidle state across the stop, per the CDP * code. If DPLL3 was passed in, or the DPLL does not support * low-power stop, return -EINVAL; otherwise, return 0. */ static int _omap3_noncore_dpll_stop(struct clk *clk) { u8 ai; if (!(clk->dpll_data->modes & (1 << DPLL_LOW_POWER_STOP))) return -EINVAL; pr_debug("clock: stopping DPLL %s\n", clk->name); ai = omap3_dpll_autoidle_read(clk); _omap3_dpll_write_clken(clk, DPLL_LOW_POWER_STOP); if (ai) omap3_dpll_allow_idle(clk); else omap3_dpll_deny_idle(clk); return 0; } /* * _omap3_noncore_dpll_program - set non-core DPLL M,N values directly * @clk: struct clk * of DPLL to set * @m: DPLL multiplier to set * @n: DPLL divider to set * @freqsel: FREQSEL value to set * * Program the DPLL with the supplied M, N values, and wait for the DPLL to * lock.. Returns -EINVAL upon error, or 0 upon success. */ static int omap3_noncore_dpll_program(struct clk *clk, u16 m, u8 n, u16 freqsel) { struct dpll_data *dd = clk->dpll_data; u32 v; /* 3430 ES2 TRM: 4.7.6.9 DPLL Programming Sequence */ _omap3_noncore_dpll_bypass(clk); /* Set jitter correction */ if (!cpu_is_omap44xx()) { v = __raw_readl(dd->control_reg); v &= ~dd->freqsel_mask; v |= freqsel << __ffs(dd->freqsel_mask); __raw_writel(v, dd->control_reg); } /* Set DPLL multiplier, divider */ v = __raw_readl(dd->mult_div1_reg); v &= ~(dd->mult_mask | dd->div1_mask); v |= m << __ffs(dd->mult_mask); v |= (n - 1) << __ffs(dd->div1_mask); __raw_writel(v, dd->mult_div1_reg); /* We let the clock framework set the other output dividers later */ /* REVISIT: Set ramp-up delay? */ _omap3_noncore_dpll_lock(clk); return 0; } /* Public functions */ /** * omap3_dpll_recalc - recalculate DPLL rate * @clk: DPLL struct clk * * Recalculate and propagate the DPLL rate. */ unsigned long omap3_dpll_recalc(struct clk *clk) { return omap2_get_dpll_rate(clk); } /* Non-CORE DPLL (e.g., DPLLs that do not control SDRC) clock functions */ /** * omap3_noncore_dpll_enable - instruct a DPLL to enter bypass or lock mode * @clk: pointer to a DPLL struct clk * * Instructs a non-CORE DPLL to enable, e.g., to enter bypass or lock. * The choice of modes depends on the DPLL's programmed rate: if it is * the same as the DPLL's parent clock, it will enter bypass; * otherwise, it will enter lock. This code will wait for the DPLL to * indicate readiness before returning, unless the DPLL takes too long * to enter the target state. Intended to be used as the struct clk's * enable function. If DPLL3 was passed in, or the DPLL does not * support low-power stop, or if the DPLL took too long to enter * bypass or lock, return -EINVAL; otherwise, return 0. */ int omap3_noncore_dpll_enable(struct clk *clk) { int r; struct dpll_data *dd; dd = clk->dpll_data; if (!dd) return -EINVAL; if (clk->rate == dd->clk_bypass->rate) { WARN_ON(clk->parent != dd->clk_bypass); r = _omap3_noncore_dpll_bypass(clk); } else { WARN_ON(clk->parent != dd->clk_ref); r = _omap3_noncore_dpll_lock(clk); } /* *FIXME: this is dubious - if clk->rate has changed, what about * propagating? */ if (!r) clk->rate = omap2_get_dpll_rate(clk); return r; } /** * omap3_noncore_dpll_disable - instruct a DPLL to enter low-power stop * @clk: pointer to a DPLL struct clk * * Instructs a non-CORE DPLL to enter low-power stop. This function is * intended for use in struct clkops. No return value. */ void omap3_noncore_dpll_disable(struct clk *clk) { _omap3_noncore_dpll_stop(clk); } /* Non-CORE DPLL rate set code */ /** * omap3_noncore_dpll_set_rate - set non-core DPLL rate * @clk: struct clk * of DPLL to set * @rate: rounded target rate * * Set the DPLL CLKOUT to the target rate. If the DPLL can enter * low-power bypass, and the target rate is the bypass source clock * rate, then configure the DPLL for bypass. Otherwise, round the * target rate if it hasn't been done already, then program and lock * the DPLL. Returns -EINVAL upon error, or 0 upon success. */ int omap3_noncore_dpll_set_rate(struct clk *clk, unsigned long rate) { struct clk *new_parent = NULL; u16 freqsel = 0; struct dpll_data *dd; int ret; if (!clk || !rate) return -EINVAL; dd = clk->dpll_data; if (!dd) return -EINVAL; if (rate == omap2_get_dpll_rate(clk)) return 0; /* * Ensure both the bypass and ref clocks are enabled prior to * doing anything; we need the bypass clock running to reprogram * the DPLL. */ omap2_clk_enable(dd->clk_bypass); omap2_clk_enable(dd->clk_ref); if (dd->clk_bypass->rate == rate && (clk->dpll_data->modes & (1 << DPLL_LOW_POWER_BYPASS))) { pr_debug("clock: %s: set rate: entering bypass.\n", clk->name); ret = _omap3_noncore_dpll_bypass(clk); if (!ret) new_parent = dd->clk_bypass; } else { if (dd->last_rounded_rate != rate) omap2_dpll_round_rate(clk, rate); if (dd->last_rounded_rate == 0) return -EINVAL; /* No freqsel on OMAP4 */ if (!cpu_is_omap44xx()) { freqsel = _omap3_dpll_compute_freqsel(clk, dd->last_rounded_n); if (!freqsel) WARN_ON(1); } pr_debug("clock: %s: set rate: locking rate to %lu.\n", clk->name, rate); ret = omap3_noncore_dpll_program(clk, dd->last_rounded_m, dd->last_rounded_n, freqsel); if (!ret) new_parent = dd->clk_ref; } if (!ret) { /* * Switch the parent clock in the heirarchy, and make sure * that the new parent's usecount is correct. Note: we * enable the new parent before disabling the old to avoid * any unnecessary hardware disable->enable transitions. */ if (clk->usecount) { omap2_clk_enable(new_parent); omap2_clk_disable(clk->parent); } clk_reparent(clk, new_parent); clk->rate = rate; } omap2_clk_disable(dd->clk_ref); omap2_clk_disable(dd->clk_bypass); return 0; } /* DPLL autoidle read/set code */ /** * omap3_dpll_autoidle_read - read a DPLL's autoidle bits * @clk: struct clk * of the DPLL to read * * Return the DPLL's autoidle bits, shifted down to bit 0. Returns * -EINVAL if passed a null pointer or if the struct clk does not * appear to refer to a DPLL. */ u32 omap3_dpll_autoidle_read(struct clk *clk) { const struct dpll_data *dd; u32 v; if (!clk || !clk->dpll_data) return -EINVAL; dd = clk->dpll_data; v = __raw_readl(dd->autoidle_reg); v &= dd->autoidle_mask; v >>= __ffs(dd->autoidle_mask); return v; } /** * omap3_dpll_allow_idle - enable DPLL autoidle bits * @clk: struct clk * of the DPLL to operate on * * Enable DPLL automatic idle control. This automatic idle mode * switching takes effect only when the DPLL is locked, at least on * OMAP3430. The DPLL will enter low-power stop when its downstream * clocks are gated. No return value. */ void omap3_dpll_allow_idle(struct clk *clk) { const struct dpll_data *dd; u32 v; if (!clk || !clk->dpll_data) return; dd = clk->dpll_data; /* * REVISIT: CORE DPLL can optionally enter low-power bypass * by writing 0x5 instead of 0x1. Add some mechanism to * optionally enter this mode. */ v = __raw_readl(dd->autoidle_reg); v &= ~dd->autoidle_mask; v |= DPLL_AUTOIDLE_LOW_POWER_STOP << __ffs(dd->autoidle_mask); __raw_writel(v, dd->autoidle_reg); } /** * omap3_dpll_deny_idle - prevent DPLL from automatically idling * @clk: struct clk * of the DPLL to operate on * * Disable DPLL automatic idle control. No return value. */ void omap3_dpll_deny_idle(struct clk *clk) { const struct dpll_data *dd; u32 v; if (!clk || !clk->dpll_data) return; dd = clk->dpll_data; v = __raw_readl(dd->autoidle_reg); v &= ~dd->autoidle_mask; v |= DPLL_AUTOIDLE_DISABLE << __ffs(dd->autoidle_mask); __raw_writel(v, dd->autoidle_reg); } /* Clock control for DPLL outputs */ /** * omap3_clkoutx2_recalc - recalculate DPLL X2 output virtual clock rate * @clk: DPLL output struct clk * * Using parent clock DPLL data, look up DPLL state. If locked, set our * rate to the dpll_clk * 2; otherwise, just use dpll_clk. */ unsigned long omap3_clkoutx2_recalc(struct clk *clk) { const struct dpll_data *dd; unsigned long rate; u32 v; struct clk *pclk; /* Walk up the parents of clk, looking for a DPLL */ pclk = clk->parent; while (pclk && !pclk->dpll_data) pclk = pclk->parent; /* clk does not have a DPLL as a parent? */ WARN_ON(!pclk); dd = pclk->dpll_data; WARN_ON(!dd->enable_mask); v = __raw_readl(dd->control_reg) & dd->enable_mask; v >>= __ffs(dd->enable_mask); if (v != OMAP3XXX_EN_DPLL_LOCKED) rate = clk->parent->rate; else rate = clk->parent->rate * 2; return rate; }