diff options
author | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-12-15 14:52:16 -0300 |
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committer | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-12-15 14:52:16 -0300 |
commit | 8d91c1e411f55d7ea91b1183a2e9f8088fb4d5be (patch) | |
tree | e9891aa6c295060d065adffd610c4f49ecf884f3 /arch/arm/mach-omap2/clkt_clksel.c | |
parent | a71852147516bc1cb5b0b3cbd13639bfd4022dc8 (diff) |
Linux-libre 4.3.2-gnu
Diffstat (limited to 'arch/arm/mach-omap2/clkt_clksel.c')
-rw-r--r-- | arch/arm/mach-omap2/clkt_clksel.c | 466 |
1 files changed, 0 insertions, 466 deletions
diff --git a/arch/arm/mach-omap2/clkt_clksel.c b/arch/arm/mach-omap2/clkt_clksel.c deleted file mode 100644 index 7ee26108a..000000000 --- a/arch/arm/mach-omap2/clkt_clksel.c +++ /dev/null @@ -1,466 +0,0 @@ -/* - * clkt_clksel.c - OMAP2/3/4 clksel 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. - * - * - * clksel clocks are clocks that do not have a fixed parent, or that - * can divide their parent's rate, or possibly both at the same time, based - * on the contents of a hardware register bitfield. - * - * All of the various mux and divider settings can be encoded into - * struct clksel* data structures, and then these can be autogenerated - * from some hardware database for each new chip generation. This - * should avoid the need to write, review, and validate a lot of new - * clock code for each new chip, since it can be exported from the SoC - * design flow. This is now done on OMAP4. - * - * The fusion of mux and divider clocks is a software creation. In - * hardware reality, the multiplexer (parent selection) and the - * divider exist separately. XXX At some point these clksel clocks - * should be split into "divider" clocks and "mux" clocks to better - * match the hardware. - * - * (The name "clksel" comes from the name of the corresponding - * register field in the OMAP2/3 family of SoCs.) - * - * XXX Currently these clocks are only used in the OMAP2/3/4 code, but - * many of the OMAP1 clocks should be convertible to use this - * mechanism. - */ -#undef DEBUG - -#include <linux/kernel.h> -#include <linux/errno.h> -#include <linux/clk-provider.h> -#include <linux/io.h> -#include <linux/bug.h> - -#include "clock.h" - -/* Private functions */ - -/** - * _get_clksel_by_parent() - return clksel struct for a given clk & parent - * @clk: OMAP struct clk ptr to inspect - * @src_clk: OMAP struct clk ptr of the parent clk to search for - * - * Scan the struct clksel array associated with the clock to find - * the element associated with the supplied parent clock address. - * Returns a pointer to the struct clksel on success or NULL on error. - */ -static const struct clksel *_get_clksel_by_parent(struct clk_hw_omap *clk, - struct clk *src_clk) -{ - const struct clksel *clks; - - if (!src_clk) - return NULL; - - for (clks = clk->clksel; clks->parent; clks++) - if (clks->parent == src_clk) - break; /* Found the requested parent */ - - if (!clks->parent) { - /* This indicates a data problem */ - WARN(1, "clock: %s: could not find parent clock %s in clksel array\n", - __clk_get_name(clk->hw.clk), __clk_get_name(src_clk)); - return NULL; - } - - return clks; -} - -/** - * _write_clksel_reg() - program a clock's clksel register in hardware - * @clk: struct clk * to program - * @v: clksel bitfield value to program (with LSB at bit 0) - * - * Shift the clksel register bitfield value @v to its appropriate - * location in the clksel register and write it in. This function - * will ensure that the write to the clksel_reg reaches its - * destination before returning -- important since PRM and CM register - * accesses can be quite slow compared to ARM cycles -- but does not - * take into account any time the hardware might take to switch the - * clock source. - */ -static void _write_clksel_reg(struct clk_hw_omap *clk, u32 field_val) -{ - u32 v; - - v = omap2_clk_readl(clk, clk->clksel_reg); - v &= ~clk->clksel_mask; - v |= field_val << __ffs(clk->clksel_mask); - omap2_clk_writel(v, clk, clk->clksel_reg); - - v = omap2_clk_readl(clk, clk->clksel_reg); /* OCP barrier */ -} - -/** - * _clksel_to_divisor() - turn clksel field value into integer divider - * @clk: OMAP struct clk to use - * @field_val: register field value to find - * - * Given a struct clk of a rate-selectable clksel clock, and a register field - * value to search for, find the corresponding clock divisor. The register - * field value should be pre-masked and shifted down so the LSB is at bit 0 - * before calling. Returns 0 on error or returns the actual integer divisor - * upon success. - */ -static u32 _clksel_to_divisor(struct clk_hw_omap *clk, u32 field_val) -{ - const struct clksel *clks; - const struct clksel_rate *clkr; - struct clk *parent; - - parent = __clk_get_parent(clk->hw.clk); - - clks = _get_clksel_by_parent(clk, parent); - if (!clks) - return 0; - - for (clkr = clks->rates; clkr->div; clkr++) { - if (!(clkr->flags & cpu_mask)) - continue; - - if (clkr->val == field_val) - break; - } - - if (!clkr->div) { - /* This indicates a data error */ - WARN(1, "clock: %s: could not find fieldval %d for parent %s\n", - __clk_get_name(clk->hw.clk), field_val, - __clk_get_name(parent)); - return 0; - } - - return clkr->div; -} - -/** - * _divisor_to_clksel() - turn clksel integer divisor into a field value - * @clk: OMAP struct clk to use - * @div: integer divisor to search for - * - * Given a struct clk of a rate-selectable clksel clock, and a clock - * divisor, find the corresponding register field value. Returns the - * register field value _before_ left-shifting (i.e., LSB is at bit - * 0); or returns 0xFFFFFFFF (~0) upon error. - */ -static u32 _divisor_to_clksel(struct clk_hw_omap *clk, u32 div) -{ - const struct clksel *clks; - const struct clksel_rate *clkr; - struct clk *parent; - - /* should never happen */ - WARN_ON(div == 0); - - parent = __clk_get_parent(clk->hw.clk); - clks = _get_clksel_by_parent(clk, parent); - if (!clks) - return ~0; - - for (clkr = clks->rates; clkr->div; clkr++) { - if (!(clkr->flags & cpu_mask)) - continue; - - if (clkr->div == div) - break; - } - - if (!clkr->div) { - pr_err("clock: %s: could not find divisor %d for parent %s\n", - __clk_get_name(clk->hw.clk), div, - __clk_get_name(parent)); - return ~0; - } - - return clkr->val; -} - -/** - * _read_divisor() - get current divisor applied to parent clock (from hdwr) - * @clk: OMAP struct clk to use. - * - * Read the current divisor register value for @clk that is programmed - * into the hardware, convert it into the actual divisor value, and - * return it; or return 0 on error. - */ -static u32 _read_divisor(struct clk_hw_omap *clk) -{ - u32 v; - - if (!clk->clksel || !clk->clksel_mask) - return 0; - - v = omap2_clk_readl(clk, clk->clksel_reg); - v &= clk->clksel_mask; - v >>= __ffs(clk->clksel_mask); - - return _clksel_to_divisor(clk, v); -} - -/* Public functions */ - -/** - * omap2_clksel_round_rate_div() - find divisor for the given clock and rate - * @clk: OMAP struct clk to use - * @target_rate: desired clock rate - * @new_div: ptr to where we should store the divisor - * - * Finds 'best' divider value in an array based on the source and target - * rates. The divider array must be sorted with smallest divider first. - * This function is also used by the DPLL3 M2 divider code. - * - * Returns the rounded clock rate or returns 0xffffffff on error. - */ -u32 omap2_clksel_round_rate_div(struct clk_hw_omap *clk, - unsigned long target_rate, - u32 *new_div) -{ - unsigned long test_rate; - const struct clksel *clks; - const struct clksel_rate *clkr; - u32 last_div = 0; - struct clk *parent; - unsigned long parent_rate; - const char *clk_name; - - parent = __clk_get_parent(clk->hw.clk); - clk_name = __clk_get_name(clk->hw.clk); - parent_rate = __clk_get_rate(parent); - - if (!clk->clksel || !clk->clksel_mask) - return ~0; - - pr_debug("clock: clksel_round_rate_div: %s target_rate %ld\n", - clk_name, target_rate); - - *new_div = 1; - - clks = _get_clksel_by_parent(clk, parent); - if (!clks) - return ~0; - - for (clkr = clks->rates; clkr->div; clkr++) { - if (!(clkr->flags & cpu_mask)) - continue; - - /* Sanity check */ - if (clkr->div <= last_div) - pr_err("clock: %s: clksel_rate table not sorted\n", - clk_name); - - last_div = clkr->div; - - test_rate = parent_rate / clkr->div; - - if (test_rate <= target_rate) - break; /* found it */ - } - - if (!clkr->div) { - pr_err("clock: %s: could not find divisor for target rate %ld for parent %s\n", - clk_name, target_rate, __clk_get_name(parent)); - return ~0; - } - - *new_div = clkr->div; - - pr_debug("clock: new_div = %d, new_rate = %ld\n", *new_div, - (parent_rate / clkr->div)); - - return parent_rate / clkr->div; -} - -/* - * Clocktype interface functions to the OMAP clock code - * (i.e., those used in struct clk field function pointers, etc.) - */ - -/** - * omap2_clksel_find_parent_index() - return the array index of the current - * hardware parent of @hw - * @hw: struct clk_hw * to find the current hardware parent of - * - * Given a struct clk_hw pointer @hw to the 'hw' member of a struct - * clk_hw_omap record representing a source-selectable hardware clock, - * read the hardware register and determine what its parent is - * currently set to. Intended to be called only by the common clock - * framework struct clk_hw_ops.get_parent function pointer. Return - * the array index of this parent clock upon success -- there is no - * way to return an error, so if we encounter an error, just WARN() - * and pretend that we know that we're doing. - */ -u8 omap2_clksel_find_parent_index(struct clk_hw *hw) -{ - struct clk_hw_omap *clk = to_clk_hw_omap(hw); - const struct clksel *clks; - const struct clksel_rate *clkr; - u32 r, found = 0; - struct clk *parent; - const char *clk_name; - int ret = 0, f = 0; - - parent = __clk_get_parent(hw->clk); - clk_name = __clk_get_name(hw->clk); - - /* XXX should be able to return an error */ - WARN((!clk->clksel || !clk->clksel_mask), - "clock: %s: attempt to call on a non-clksel clock", clk_name); - - r = omap2_clk_readl(clk, clk->clksel_reg) & clk->clksel_mask; - r >>= __ffs(clk->clksel_mask); - - for (clks = clk->clksel; clks->parent && !found; clks++) { - for (clkr = clks->rates; clkr->div && !found; clkr++) { - if (!(clkr->flags & cpu_mask)) - continue; - - if (clkr->val == r) { - found = 1; - ret = f; - } - } - f++; - } - - /* This indicates a data error */ - WARN(!found, "clock: %s: init parent: could not find regval %0x\n", - clk_name, r); - - return ret; -} - - -/** - * omap2_clksel_recalc() - function ptr to pass via struct clk .recalc field - * @clk: struct clk * - * - * This function is intended to be called only by the clock framework. - * Each clksel clock should have its struct clk .recalc field set to this - * function. Returns the clock's current rate, based on its parent's rate - * and its current divisor setting in the hardware. - */ -unsigned long omap2_clksel_recalc(struct clk_hw *hw, unsigned long parent_rate) -{ - unsigned long rate; - u32 div = 0; - struct clk_hw_omap *clk = to_clk_hw_omap(hw); - - if (!parent_rate) - return 0; - - div = _read_divisor(clk); - if (!div) - rate = parent_rate; - else - rate = parent_rate / div; - - pr_debug("%s: recalc'd %s's rate to %lu (div %d)\n", __func__, - __clk_get_name(hw->clk), rate, div); - - return rate; -} - -/** - * omap2_clksel_round_rate() - find rounded rate for the given clock and rate - * @clk: OMAP struct clk to use - * @target_rate: desired clock rate - * - * This function is intended to be called only by the clock framework. - * Finds best target rate based on the source clock and possible dividers. - * rates. The divider array must be sorted with smallest divider first. - * - * Returns the rounded clock rate or returns 0xffffffff on error. - */ -long omap2_clksel_round_rate(struct clk_hw *hw, unsigned long target_rate, - unsigned long *parent_rate) -{ - struct clk_hw_omap *clk = to_clk_hw_omap(hw); - u32 new_div; - - return omap2_clksel_round_rate_div(clk, target_rate, &new_div); -} - -/** - * omap2_clksel_set_rate() - program clock rate in hardware - * @clk: struct clk * to program rate - * @rate: target rate to program - * - * This function is intended to be called only by the clock framework. - * Program @clk's rate to @rate in the hardware. The clock can be - * either enabled or disabled when this happens, although if the clock - * is enabled, some downstream devices may glitch or behave - * unpredictably when the clock rate is changed - this depends on the - * hardware. This function does not currently check the usecount of - * the clock, so if multiple drivers are using the clock, and the rate - * is changed, they will all be affected without any notification. - * Returns -EINVAL upon error, or 0 upon success. - */ -int omap2_clksel_set_rate(struct clk_hw *hw, unsigned long rate, - unsigned long parent_rate) -{ - struct clk_hw_omap *clk = to_clk_hw_omap(hw); - u32 field_val, validrate, new_div = 0; - - if (!clk->clksel || !clk->clksel_mask) - return -EINVAL; - - validrate = omap2_clksel_round_rate_div(clk, rate, &new_div); - if (validrate != rate) - return -EINVAL; - - field_val = _divisor_to_clksel(clk, new_div); - if (field_val == ~0) - return -EINVAL; - - _write_clksel_reg(clk, field_val); - - pr_debug("clock: %s: set rate to %ld\n", __clk_get_name(hw->clk), - __clk_get_rate(hw->clk)); - - return 0; -} - -/* - * Clksel parent setting function - not passed in struct clk function - * pointer - instead, the OMAP clock code currently assumes that any - * parent-setting clock is a clksel clock, and calls - * omap2_clksel_set_parent() by default - */ - -/** - * omap2_clksel_set_parent() - change a clock's parent clock - * @clk: struct clk * of the child clock - * @new_parent: struct clk * of the new parent clock - * - * This function is intended to be called only by the clock framework. - * Change the parent clock of clock @clk to @new_parent. This is - * intended to be used while @clk is disabled. This function does not - * currently check the usecount of the clock, so if multiple drivers - * are using the clock, and the parent is changed, they will all be - * affected without any notification. Returns -EINVAL upon error, or - * 0 upon success. - */ -int omap2_clksel_set_parent(struct clk_hw *hw, u8 field_val) -{ - struct clk_hw_omap *clk = to_clk_hw_omap(hw); - - if (!clk->clksel || !clk->clksel_mask) - return -EINVAL; - - _write_clksel_reg(clk, field_val); - return 0; -} |