alistair23-linux/arch/arm/mach-omap2/clock2xxx.c
Ranjith Lohithakshan 419cc97d36 OMAP2/3 clock: Extend find_idlest() to pass back idle state value
Current implementation defines clock idle state indicators based on the
cpu information (cpu_is_omap24xx() or cpu_is_omap34xx()) in a system wide
manner. This patch extends the find_idlest() function in clkops to pass
back the idle state indicator for that clock, thus allowing idle state
indicators to be defined on a per clock basis if required.

This is specifically needed on AM35xx devices as the new IPSS clocks
indicates the idle status (0 is idle, 1 is ready) in a way just
opposite to how its handled in OMAP3 (0 is ready, 1 is idle).

Signed-off-by: Ranjith Lohithakshan <ranjithl@ti.com>
[paul@pwsan.com: updated to apply after commit 98c45457 et seq.]
Signed-off-by: Paul Walmsley <paul@pwsan.com>
2010-02-24 12:05:54 -07:00

126 lines
3.1 KiB
C

/*
* clock2xxx.c - OMAP2xxx-specific clock integration code
*
* Copyright (C) 2005-2008 Texas Instruments, Inc.
* Copyright (C) 2004-2010 Nokia Corporation
*
* Contacts:
* Richard Woodruff <r-woodruff2@ti.com>
* Paul Walmsley
*
* Based on earlier work by Tuukka Tikkanen, Tony Lindgren,
* Gordon McNutt and RidgeRun, Inc.
*
* 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 <plat/clock.h>
#include "clock.h"
#include "clock2xxx.h"
#include "cm.h"
#include "cm-regbits-24xx.h"
struct clk *vclk, *sclk, *dclk;
/*
* Omap24xx specific clock functions
*/
#ifdef CONFIG_ARCH_OMAP2430
/**
* omap2430_clk_i2chs_find_idlest - return CM_IDLEST info for 2430 I2CHS
* @clk: struct clk * being enabled
* @idlest_reg: void __iomem ** to store CM_IDLEST reg address into
* @idlest_bit: pointer to a u8 to store the CM_IDLEST bit shift into
* @idlest_val: pointer to a u8 to store the CM_IDLEST indicator
*
* OMAP2430 I2CHS CM_IDLEST bits are in CM_IDLEST1_CORE, but the
* CM_*CLKEN bits are in CM_{I,F}CLKEN2_CORE. This custom function
* passes back the correct CM_IDLEST register address for I2CHS
* modules. No return value.
*/
static void omap2430_clk_i2chs_find_idlest(struct clk *clk,
void __iomem **idlest_reg,
u8 *idlest_bit,
u8 *idlest_val)
{
*idlest_reg = OMAP_CM_REGADDR(CORE_MOD, CM_IDLEST);
*idlest_bit = clk->enable_bit;
*idlest_val = OMAP24XX_CM_IDLEST_VAL;
}
#else
#define omap2430_clk_i2chs_find_idlest NULL
#endif
/* 2430 I2CHS has non-standard IDLEST register */
const struct clkops clkops_omap2430_i2chs_wait = {
.enable = omap2_dflt_clk_enable,
.disable = omap2_dflt_clk_disable,
.find_idlest = omap2430_clk_i2chs_find_idlest,
.find_companion = omap2_clk_dflt_find_companion,
};
/*
* Set clocks for bypass mode for reboot to work.
*/
void omap2xxx_clk_prepare_for_reboot(void)
{
u32 rate;
if (vclk == NULL || sclk == NULL)
return;
rate = clk_get_rate(sclk);
clk_set_rate(vclk, rate);
}
/*
* Switch the MPU rate if specified on cmdline.
* We cannot do this early until cmdline is parsed.
*/
static int __init omap2xxx_clk_arch_init(void)
{
struct clk *virt_prcm_set, *sys_ck, *dpll_ck, *mpu_ck;
unsigned long sys_ck_rate;
if (!cpu_is_omap24xx())
return 0;
if (!mpurate)
return -EINVAL;
virt_prcm_set = clk_get(NULL, "virt_prcm_set");
sys_ck = clk_get(NULL, "sys_ck");
dpll_ck = clk_get(NULL, "dpll_ck");
mpu_ck = clk_get(NULL, "mpu_ck");
if (clk_set_rate(virt_prcm_set, mpurate))
printk(KERN_ERR "Could not find matching MPU rate\n");
recalculate_root_clocks();
sys_ck_rate = clk_get_rate(sys_ck);
pr_info("Switched to new clocking rate (Crystal/DPLL/MPU): "
"%ld.%01ld/%ld/%ld MHz\n",
(sys_ck_rate / 1000000), (sys_ck_rate / 100000) % 10,
(clk_get_rate(dpll_ck) / 1000000),
(clk_get_rate(mpu_ck) / 1000000));
return 0;
}
arch_initcall(omap2xxx_clk_arch_init);