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authorJosé Pekkarinen <jose.pekkarinen@nokia.com>2016-04-11 10:41:07 +0300
committerJosé Pekkarinen <jose.pekkarinen@nokia.com>2016-04-13 08:17:18 +0300
commite09b41010ba33a20a87472ee821fa407a5b8da36 (patch)
treed10dc367189862e7ca5c592f033dc3726e1df4e3 /kernel/arch/arm/mach-omap2/clkt_dpll.c
parentf93b97fd65072de626c074dbe099a1fff05ce060 (diff)
These changes are the raw update to linux-4.4.6-rt14. Kernel sources
are taken from kernel.org, and rt patch from the rt wiki download page. During the rebasing, the following patch collided: Force tick interrupt and get rid of softirq magic(I70131fb85). Collisions have been removed because its logic was found on the source already. Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769 Signed-off-by: José Pekkarinen <jose.pekkarinen@nokia.com>
Diffstat (limited to 'kernel/arch/arm/mach-omap2/clkt_dpll.c')
-rw-r--r--kernel/arch/arm/mach-omap2/clkt_dpll.c370
1 files changed, 0 insertions, 370 deletions
diff --git a/kernel/arch/arm/mach-omap2/clkt_dpll.c b/kernel/arch/arm/mach-omap2/clkt_dpll.c
deleted file mode 100644
index f251a14cb..000000000
--- a/kernel/arch/arm/mach-omap2/clkt_dpll.c
+++ /dev/null
@@ -1,370 +0,0 @@
-/*
- * OMAP2/3/4 DPLL clock functions
- *
- * Copyright (C) 2005-2008 Texas Instruments, Inc.
- * Copyright (C) 2004-2010 Nokia Corporation
- *
- * Contacts:
- * Richard Woodruff <r-woodruff2@ti.com>
- * Paul Walmsley
- *
- * 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.
- */
-#undef DEBUG
-
-#include <linux/kernel.h>
-#include <linux/errno.h>
-#include <linux/clk-provider.h>
-#include <linux/io.h>
-
-#include <asm/div64.h>
-
-#include "clock.h"
-
-/* DPLL rate rounding: minimum DPLL multiplier, divider values */
-#define DPLL_MIN_MULTIPLIER 2
-#define DPLL_MIN_DIVIDER 1
-
-/* Possible error results from _dpll_test_mult */
-#define DPLL_MULT_UNDERFLOW -1
-
-/*
- * Scale factor to mitigate roundoff errors in DPLL rate rounding.
- * The higher the scale factor, the greater the risk of arithmetic overflow,
- * but the closer the rounded rate to the target rate. DPLL_SCALE_FACTOR
- * must be a power of DPLL_SCALE_BASE.
- */
-#define DPLL_SCALE_FACTOR 64
-#define DPLL_SCALE_BASE 2
-#define DPLL_ROUNDING_VAL ((DPLL_SCALE_BASE / 2) * \
- (DPLL_SCALE_FACTOR / DPLL_SCALE_BASE))
-
-/*
- * DPLL valid Fint frequency range for OMAP36xx and OMAP4xxx.
- * From device data manual section 4.3 "DPLL and DLL Specifications".
- */
-#define OMAP3PLUS_DPLL_FINT_JTYPE_MIN 500000
-#define OMAP3PLUS_DPLL_FINT_JTYPE_MAX 2500000
-
-/* _dpll_test_fint() return codes */
-#define DPLL_FINT_UNDERFLOW -1
-#define DPLL_FINT_INVALID -2
-
-/* Private functions */
-
-/*
- * _dpll_test_fint - test whether an Fint value is valid for the DPLL
- * @clk: DPLL struct clk to test
- * @n: divider value (N) to test
- *
- * Tests whether a particular divider @n will result in a valid DPLL
- * internal clock frequency Fint. See the 34xx TRM 4.7.6.2 "DPLL Jitter
- * Correction". Returns 0 if OK, -1 if the enclosing loop can terminate
- * (assuming that it is counting N upwards), or -2 if the enclosing loop
- * should skip to the next iteration (again assuming N is increasing).
- */
-static int _dpll_test_fint(struct clk_hw_omap *clk, unsigned int n)
-{
- struct dpll_data *dd;
- long fint, fint_min, fint_max;
- int ret = 0;
-
- dd = clk->dpll_data;
-
- /* DPLL divider must result in a valid jitter correction val */
- fint = __clk_get_rate(__clk_get_parent(clk->hw.clk)) / n;
-
- if (dd->flags & DPLL_J_TYPE) {
- fint_min = OMAP3PLUS_DPLL_FINT_JTYPE_MIN;
- fint_max = OMAP3PLUS_DPLL_FINT_JTYPE_MAX;
- } else {
- fint_min = ti_clk_features.fint_min;
- fint_max = ti_clk_features.fint_max;
- }
-
- if (!fint_min || !fint_max) {
- WARN(1, "No fint limits available!\n");
- return DPLL_FINT_INVALID;
- }
-
- if (fint < ti_clk_features.fint_min) {
- pr_debug("rejecting n=%d due to Fint failure, lowering max_divider\n",
- n);
- dd->max_divider = n;
- ret = DPLL_FINT_UNDERFLOW;
- } else if (fint > ti_clk_features.fint_max) {
- pr_debug("rejecting n=%d due to Fint failure, boosting min_divider\n",
- n);
- dd->min_divider = n;
- ret = DPLL_FINT_INVALID;
- } else if (fint > ti_clk_features.fint_band1_max &&
- fint < ti_clk_features.fint_band2_min) {
- pr_debug("rejecting n=%d due to Fint failure\n", n);
- ret = DPLL_FINT_INVALID;
- }
-
- return ret;
-}
-
-static unsigned long _dpll_compute_new_rate(unsigned long parent_rate,
- unsigned int m, unsigned int n)
-{
- unsigned long long num;
-
- num = (unsigned long long)parent_rate * m;
- do_div(num, n);
- return num;
-}
-
-/*
- * _dpll_test_mult - test a DPLL multiplier value
- * @m: pointer to the DPLL m (multiplier) value under test
- * @n: current DPLL n (divider) value under test
- * @new_rate: pointer to storage for the resulting rounded rate
- * @target_rate: the desired DPLL rate
- * @parent_rate: the DPLL's parent clock rate
- *
- * This code tests a DPLL multiplier value, ensuring that the
- * resulting rate will not be higher than the target_rate, and that
- * the multiplier value itself is valid for the DPLL. Initially, the
- * integer pointed to by the m argument should be prescaled by
- * multiplying by DPLL_SCALE_FACTOR. The code will replace this with
- * a non-scaled m upon return. This non-scaled m will result in a
- * new_rate as close as possible to target_rate (but not greater than
- * target_rate) given the current (parent_rate, n, prescaled m)
- * triple. Returns DPLL_MULT_UNDERFLOW in the event that the
- * non-scaled m attempted to underflow, which can allow the calling
- * function to bail out early; or 0 upon success.
- */
-static int _dpll_test_mult(int *m, int n, unsigned long *new_rate,
- unsigned long target_rate,
- unsigned long parent_rate)
-{
- int r = 0, carry = 0;
-
- /* Unscale m and round if necessary */
- if (*m % DPLL_SCALE_FACTOR >= DPLL_ROUNDING_VAL)
- carry = 1;
- *m = (*m / DPLL_SCALE_FACTOR) + carry;
-
- /*
- * The new rate must be <= the target rate to avoid programming
- * a rate that is impossible for the hardware to handle
- */
- *new_rate = _dpll_compute_new_rate(parent_rate, *m, n);
- if (*new_rate > target_rate) {
- (*m)--;
- *new_rate = 0;
- }
-
- /* Guard against m underflow */
- if (*m < DPLL_MIN_MULTIPLIER) {
- *m = DPLL_MIN_MULTIPLIER;
- *new_rate = 0;
- r = DPLL_MULT_UNDERFLOW;
- }
-
- if (*new_rate == 0)
- *new_rate = _dpll_compute_new_rate(parent_rate, *m, n);
-
- return r;
-}
-
-/**
- * _omap2_dpll_is_in_bypass - check if DPLL is in bypass mode or not
- * @v: bitfield value of the DPLL enable
- *
- * Checks given DPLL enable bitfield to see whether the DPLL is in bypass
- * mode or not. Returns 1 if the DPLL is in bypass, 0 otherwise.
- */
-static int _omap2_dpll_is_in_bypass(u32 v)
-{
- u8 mask, val;
-
- mask = ti_clk_features.dpll_bypass_vals;
-
- /*
- * Each set bit in the mask corresponds to a bypass value equal
- * to the bitshift. Go through each set-bit in the mask and
- * compare against the given register value.
- */
- while (mask) {
- val = __ffs(mask);
- mask ^= (1 << val);
- if (v == val)
- return 1;
- }
-
- return 0;
-}
-
-/* Public functions */
-u8 omap2_init_dpll_parent(struct clk_hw *hw)
-{
- struct clk_hw_omap *clk = to_clk_hw_omap(hw);
- u32 v;
- struct dpll_data *dd;
-
- dd = clk->dpll_data;
- if (!dd)
- return -EINVAL;
-
- v = omap2_clk_readl(clk, dd->control_reg);
- v &= dd->enable_mask;
- v >>= __ffs(dd->enable_mask);
-
- /* Reparent the struct clk in case the dpll is in bypass */
- if (_omap2_dpll_is_in_bypass(v))
- return 1;
-
- return 0;
-}
-
-/**
- * omap2_get_dpll_rate - returns the current DPLL CLKOUT rate
- * @clk: struct clk * of a DPLL
- *
- * DPLLs can be locked or bypassed - basically, enabled or disabled.
- * When locked, the DPLL output depends on the M and N values. When
- * bypassed, on OMAP2xxx, the output rate is either the 32KiHz clock
- * or sys_clk. Bypass rates on OMAP3 depend on the DPLL: DPLLs 1 and
- * 2 are bypassed with dpll1_fclk and dpll2_fclk respectively
- * (generated by DPLL3), while DPLL 3, 4, and 5 bypass rates are sys_clk.
- * Returns the current DPLL CLKOUT rate (*not* CLKOUTX2) if the DPLL is
- * locked, or the appropriate bypass rate if the DPLL is bypassed, or 0
- * if the clock @clk is not a DPLL.
- */
-unsigned long omap2_get_dpll_rate(struct clk_hw_omap *clk)
-{
- long long dpll_clk;
- u32 dpll_mult, dpll_div, v;
- struct dpll_data *dd;
-
- dd = clk->dpll_data;
- if (!dd)
- return 0;
-
- /* Return bypass rate if DPLL is bypassed */
- v = omap2_clk_readl(clk, dd->control_reg);
- v &= dd->enable_mask;
- v >>= __ffs(dd->enable_mask);
-
- if (_omap2_dpll_is_in_bypass(v))
- return __clk_get_rate(dd->clk_bypass);
-
- v = omap2_clk_readl(clk, dd->mult_div1_reg);
- dpll_mult = v & dd->mult_mask;
- dpll_mult >>= __ffs(dd->mult_mask);
- dpll_div = v & dd->div1_mask;
- dpll_div >>= __ffs(dd->div1_mask);
-
- dpll_clk = (long long) __clk_get_rate(dd->clk_ref) * dpll_mult;
- do_div(dpll_clk, dpll_div + 1);
-
- return dpll_clk;
-}
-
-/* DPLL rate rounding code */
-
-/**
- * omap2_dpll_round_rate - round a target rate for an OMAP DPLL
- * @clk: struct clk * for a DPLL
- * @target_rate: desired DPLL clock rate
- *
- * Given a DPLL and a desired target rate, round the target rate to a
- * possible, programmable rate for this DPLL. Attempts to select the
- * minimum possible n. Stores the computed (m, n) in the DPLL's
- * dpll_data structure so set_rate() will not need to call this
- * (expensive) function again. Returns ~0 if the target rate cannot
- * be rounded, or the rounded rate upon success.
- */
-long omap2_dpll_round_rate(struct clk_hw *hw, unsigned long target_rate,
- unsigned long *parent_rate)
-{
- struct clk_hw_omap *clk = to_clk_hw_omap(hw);
- int m, n, r, scaled_max_m;
- int min_delta_m = INT_MAX, min_delta_n = INT_MAX;
- unsigned long scaled_rt_rp;
- unsigned long new_rate = 0;
- struct dpll_data *dd;
- unsigned long ref_rate;
- long delta;
- long prev_min_delta = LONG_MAX;
- const char *clk_name;
-
- if (!clk || !clk->dpll_data)
- return ~0;
-
- dd = clk->dpll_data;
-
- ref_rate = __clk_get_rate(dd->clk_ref);
- clk_name = __clk_get_name(hw->clk);
- pr_debug("clock: %s: starting DPLL round_rate, target rate %lu\n",
- clk_name, target_rate);
-
- scaled_rt_rp = target_rate / (ref_rate / DPLL_SCALE_FACTOR);
- scaled_max_m = dd->max_multiplier * DPLL_SCALE_FACTOR;
-
- dd->last_rounded_rate = 0;
-
- for (n = dd->min_divider; n <= dd->max_divider; n++) {
-
- /* Is the (input clk, divider) pair valid for the DPLL? */
- r = _dpll_test_fint(clk, n);
- if (r == DPLL_FINT_UNDERFLOW)
- break;
- else if (r == DPLL_FINT_INVALID)
- continue;
-
- /* Compute the scaled DPLL multiplier, based on the divider */
- m = scaled_rt_rp * n;
-
- /*
- * Since we're counting n up, a m overflow means we
- * can bail out completely (since as n increases in
- * the next iteration, there's no way that m can
- * increase beyond the current m)
- */
- if (m > scaled_max_m)
- break;
-
- r = _dpll_test_mult(&m, n, &new_rate, target_rate,
- ref_rate);
-
- /* m can't be set low enough for this n - try with a larger n */
- if (r == DPLL_MULT_UNDERFLOW)
- continue;
-
- /* skip rates above our target rate */
- delta = target_rate - new_rate;
- if (delta < 0)
- continue;
-
- if (delta < prev_min_delta) {
- prev_min_delta = delta;
- min_delta_m = m;
- min_delta_n = n;
- }
-
- pr_debug("clock: %s: m = %d: n = %d: new_rate = %lu\n",
- clk_name, m, n, new_rate);
-
- if (delta == 0)
- break;
- }
-
- if (prev_min_delta == LONG_MAX) {
- pr_debug("clock: %s: cannot round to rate %lu\n",
- clk_name, target_rate);
- return ~0;
- }
-
- dd->last_rounded_m = min_delta_m;
- dd->last_rounded_n = min_delta_n;
- dd->last_rounded_rate = target_rate - prev_min_delta;
-
- return dd->last_rounded_rate;
-}
-