diff options
Diffstat (limited to 'arch/arm/mach-omap2/dpll3xxx.c')
| -rw-r--r-- | arch/arm/mach-omap2/dpll3xxx.c | 599 |
1 files changed, 599 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/dpll3xxx.c b/arch/arm/mach-omap2/dpll3xxx.c new file mode 100644 index 000000000000..b32ccd954a1b --- /dev/null +++ b/arch/arm/mach-omap2/dpll3xxx.c @@ -0,0 +1,599 @@ +/* + * OMAP3/4 - specific DPLL control functions + * + * Copyright (C) 2009-2010 Texas Instruments, Inc. + * Copyright (C) 2009-2010 Nokia Corporation + * + * Written by Paul Walmsley + * Testing and integration fixes by Jouni Högander + * + * 36xx support added by Vishwanath BS, Richard Woodruff, and Nishanth + * Menon + * + * 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 <linux/kernel.h> +#include <linux/device.h> +#include <linux/list.h> +#include <linux/errno.h> +#include <linux/delay.h> +#include <linux/clk.h> +#include <linux/io.h> +#include <linux/bitops.h> + +#include <plat/cpu.h> +#include <plat/clock.h> +#include <asm/clkdev.h> + +#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; +} + +/** + * lookup_dco_sddiv - Set j-type DPLL4 compensation variables + * @clk: pointer to a DPLL struct clk + * @dco: digital control oscillator selector + * @sd_div: target sigma-delta divider + * @m: DPLL multiplier to set + * @n: DPLL divider to set + * + * See 36xx TRM section 3.5.3.3.3.2 "Type B DPLL (Low-Jitter)" + * + * XXX This code is not needed for 3430/AM35xx; can it be optimized + * out in non-multi-OMAP builds for those chips? + */ +static void lookup_dco_sddiv(struct clk *clk, u8 *dco, u8 *sd_div, u16 m, + u8 n) +{ + unsigned long fint, clkinp, sd; /* watch out for overflow */ + int mod1, mod2; + + clkinp = clk->parent->rate; + fint = (clkinp / n) * m; + + if (fint < 1000000000) + *dco = 2; + else + *dco = 4; + /* + * target sigma-delta to near 250MHz + * sd = ceil[(m/(n+1)) * (clkinp_MHz / 250)] + */ + clkinp /= 100000; /* shift from MHz to 10*Hz for 38.4 and 19.2 */ + mod1 = (clkinp * m) % (250 * n); + sd = (clkinp * m) / (250 * n); + mod2 = sd % 10; + sd /= 10; + + if (mod1 || mod2) + sd++; + *sd_div = sd; +} + +/* + * _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. No jitter correction for OMAP4 and 3630 + * since freqsel field is no longer present + */ + if (!cpu_is_omap44xx() && !cpu_is_omap3630()) { + 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); + + /* + * XXX This code is not needed for 3430/AM35XX; can it be optimized + * out in non-multi-OMAP builds for those chips? + */ + if ((dd->flags & DPLL_J_TYPE) && !(dd->flags & DPLL_NO_DCO_SEL)) { + u8 dco, sd_div; + lookup_dco_sddiv(clk, &dco, &sd_div, m, n); + /* XXX This probably will need revision for OMAP4 */ + v &= ~(OMAP3630_PERIPH_DPLL_DCO_SEL_MASK + | OMAP3630_PERIPH_DPLL_SD_DIV_MASK); + v |= dco << __ffs(OMAP3630_PERIPH_DPLL_DCO_SEL_MASK); + v |= sd_div << __ffs(OMAP3630_PERIPH_DPLL_SD_DIV_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 and OMAP3630 */ + if (!cpu_is_omap44xx() && !cpu_is_omap3630()) { + 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) || (dd->flags & DPLL_J_TYPE)) + rate = clk->parent->rate; + else + rate = clk->parent->rate * 2; + return rate; +} |