ARM: clps711x: Added simple clock framework

Modern CPUs from CLPS711X-line can operate at frequencies other than 73 MHz.
This patch adds simple clock framework for handling all possible CPU rates.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
This commit is contained in:
Alexander Shiyan 2012-08-21 20:59:35 +04:00 committed by Arnd Bergmann
parent 55d512e245
commit 61ae48c3cb
3 changed files with 76 additions and 38 deletions

View File

@ -384,6 +384,8 @@ config ARCH_CLPS711X
bool "Cirrus Logic CLPS711x/EP721x/EP731x-based"
select CPU_ARM720T
select ARCH_USES_GETTIMEOFFSET
select COMMON_CLK
select CLKDEV_LOOKUP
select NEED_MACH_MEMORY_H
help
Support for Cirrus Logic 711x/721x/731x based boards.

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@ -19,24 +19,25 @@
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/io.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/sched.h>
#include <linux/clk.h>
#include <linux/clkdev.h>
#include <linux/clk-provider.h>
#include <asm/sizes.h>
#include <mach/hardware.h>
#include <asm/irq.h>
#include <asm/leds.h>
#include <asm/pgtable.h>
#include <asm/page.h>
#include <asm/mach/map.h>
#include <asm/mach/time.h>
#include <asm/system_misc.h>
#include <mach/hardware.h>
static struct clk *clk_pll, *clk_bus, *clk_uart, *clk_timerl, *clk_timerh,
*clk_tint, *clk_spi;
static unsigned long latch;
/*
* This maps the generic CLPS711x registers
*/
@ -166,8 +167,8 @@ void __init clps711x_init_irq(void)
static unsigned long clps711x_gettimeoffset(void)
{
unsigned long hwticks;
hwticks = LATCH - (clps_readl(TC2D) & 0xffff); /* since last underflow */
return (hwticks * (tick_nsec / 1000)) / LATCH;
hwticks = latch - (clps_readl(TC2D) & 0xffff);
return (hwticks * (tick_nsec / 1000)) / latch;
}
/*
@ -185,15 +186,71 @@ static struct irqaction clps711x_timer_irq = {
.handler = p720t_timer_interrupt,
};
static void add_fixed_clk(struct clk *clk, const char *name, int rate)
{
clk = clk_register_fixed_rate(NULL, name, NULL, CLK_IS_ROOT, rate);
clk_register_clkdev(clk, name, NULL);
}
static void __init clps711x_timer_init(void)
{
unsigned int syscon;
int osc, ext, pll, cpu, bus, timl, timh, uart, spi;
u32 tmp;
syscon = clps_readl(SYSCON1);
syscon |= SYSCON1_TC2S | SYSCON1_TC2M;
clps_writel(syscon, SYSCON1);
osc = 3686400;
ext = 13000000;
clps_writel(LATCH-1, TC2D); /* 512kHz / 100Hz - 1 */
tmp = clps_readl(PLLR) >> 24;
if (tmp)
pll = (osc * tmp) / 2;
else
pll = 73728000; /* Default value */
tmp = clps_readl(SYSFLG2);
if (tmp & SYSFLG2_CKMODE) {
cpu = ext;
bus = cpu;
spi = 135400;
} else {
cpu = pll;
if (cpu >= 36864000)
bus = cpu / 2;
else
bus = 36864000 / 2;
spi = cpu / 576;
}
uart = bus / 10;
if (tmp & SYSFLG2_CKMODE) {
tmp = clps_readl(SYSCON2);
if (tmp & SYSCON2_OSTB)
timh = ext / 26;
else
timh = 541440;
} else
timh = cpu / 144;
timl = timh / 256;
/* All clocks are fixed */
add_fixed_clk(clk_pll, "pll", pll);
add_fixed_clk(clk_bus, "bus", bus);
add_fixed_clk(clk_uart, "uart", uart);
add_fixed_clk(clk_timerl, "timer_lf", timl);
add_fixed_clk(clk_timerh, "timer_hf", timh);
add_fixed_clk(clk_tint, "tint", 64);
add_fixed_clk(clk_spi, "spi", spi);
pr_info("CPU frequency set at %i Hz.\n", cpu);
latch = (timh + HZ / 2) / HZ;
tmp = clps_readl(SYSCON1);
tmp |= SYSCON1_TC2S | SYSCON1_TC2M;
clps_writel(tmp, SYSCON1);
clps_writel(latch - 1, TC2D);
setup_irq(IRQ_TC2OI, &clps711x_timer_irq);
}

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@ -1,23 +1,2 @@
/*
* arch/arm/mach-clps711x/include/mach/timex.h
*
* Prospector 720T architecture timex specifications
*
* Copyright (C) 2000 Deep Blue Solutions Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/* Bogus value */
#define CLOCK_TICK_RATE 512000