linux/arch/arm/mach-omap2/clock3xxx.c
Tero Kristo 846fdf2a3d ARM: OMAP2+: clock: remove support for legacy mpurate command line param
The legacy support is wrong and dangerous, as it doesn't take any
OPPs into account and does not scale voltages. Switching mpurate should
be handled through cpufreq.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
2015-06-02 12:31:13 +03:00

111 lines
3.3 KiB
C

/*
* OMAP3-specific clock framework functions
*
* Copyright (C) 2007-2008 Texas Instruments, Inc.
* Copyright (C) 2007-2010 Nokia Corporation
*
* Paul Walmsley
* 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.
*/
#undef DEBUG
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/clk.h>
#include <linux/io.h>
#include "soc.h"
#include "clock.h"
#include "clock3xxx.h"
#include "prm2xxx_3xxx.h"
#include "prm-regbits-34xx.h"
#include "cm2xxx_3xxx.h"
#include "cm-regbits-34xx.h"
/*
* DPLL5_FREQ_FOR_USBHOST: USBHOST and USBTLL are the only clocks
* that are sourced by DPLL5, and both of these require this clock
* to be at 120 MHz for proper operation.
*/
#define DPLL5_FREQ_FOR_USBHOST 120000000
/* needed by omap3_core_dpll_m2_set_rate() */
struct clk *sdrc_ick_p, *arm_fck_p;
/**
* omap3_dpll4_set_rate - set rate for omap3 per-dpll
* @hw: clock to change
* @rate: target rate for clock
* @parent_rate: rate of the parent clock
*
* Check if the current SoC supports the per-dpll reprogram operation
* or not, and then do the rate change if supported. Returns -EINVAL
* if not supported, 0 for success, and potential error codes from the
* clock rate change.
*/
int omap3_dpll4_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
/*
* According to the 12-5 CDP code from TI, "Limitation 2.5"
* on 3430ES1 prevents us from changing DPLL multipliers or dividers
* on DPLL4.
*/
if (ti_clk_get_features()->flags & TI_CLK_DPLL4_DENY_REPROGRAM) {
pr_err("clock: DPLL4 cannot change rate due to silicon 'Limitation 2.5' on 3430ES1.\n");
return -EINVAL;
}
return omap3_noncore_dpll_set_rate(hw, rate, parent_rate);
}
/**
* omap3_dpll4_set_rate_and_parent - set rate and parent for omap3 per-dpll
* @hw: clock to change
* @rate: target rate for clock
* @parent_rate: rate of the parent clock
* @index: parent index, 0 - reference clock, 1 - bypass clock
*
* Check if the current SoC support the per-dpll reprogram operation
* or not, and then do the rate + parent change if supported. Returns
* -EINVAL if not supported, 0 for success, and potential error codes
* from the clock rate change.
*/
int omap3_dpll4_set_rate_and_parent(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate, u8 index)
{
if (ti_clk_get_features()->flags & TI_CLK_DPLL4_DENY_REPROGRAM) {
pr_err("clock: DPLL4 cannot change rate due to silicon 'Limitation 2.5' on 3430ES1.\n");
return -EINVAL;
}
return omap3_noncore_dpll_set_rate_and_parent(hw, rate, parent_rate,
index);
}
void __init omap3_clk_lock_dpll5(void)
{
struct clk *dpll5_clk;
struct clk *dpll5_m2_clk;
dpll5_clk = clk_get(NULL, "dpll5_ck");
clk_set_rate(dpll5_clk, DPLL5_FREQ_FOR_USBHOST);
clk_prepare_enable(dpll5_clk);
/* Program dpll5_m2_clk divider for no division */
dpll5_m2_clk = clk_get(NULL, "dpll5_m2_ck");
clk_prepare_enable(dpll5_m2_clk);
clk_set_rate(dpll5_m2_clk, DPLL5_FREQ_FOR_USBHOST);
clk_disable_unprepare(dpll5_m2_clk);
clk_disable_unprepare(dpll5_clk);
return;
}