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
Arnd Bergmann
parent
55d512e245
commit
61ae48c3cb
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@ -384,6 +384,8 @@ config ARCH_CLPS711X
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bool "Cirrus Logic CLPS711x/EP721x/EP731x-based"
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select CPU_ARM720T
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select ARCH_USES_GETTIMEOFFSET
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select COMMON_CLK
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select CLKDEV_LOOKUP
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select NEED_MACH_MEMORY_H
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help
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Support for Cirrus Logic 711x/721x/731x based boards.
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@ -19,24 +19,25 @@
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/io.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/io.h>
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#include <linux/irq.h>
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#include <linux/sched.h>
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#include <linux/clk.h>
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#include <linux/clkdev.h>
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#include <linux/clk-provider.h>
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#include <asm/sizes.h>
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#include <mach/hardware.h>
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#include <asm/irq.h>
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#include <asm/leds.h>
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#include <asm/pgtable.h>
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#include <asm/page.h>
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#include <asm/mach/map.h>
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#include <asm/mach/time.h>
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#include <asm/system_misc.h>
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#include <mach/hardware.h>
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static struct clk *clk_pll, *clk_bus, *clk_uart, *clk_timerl, *clk_timerh,
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*clk_tint, *clk_spi;
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static unsigned long latch;
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/*
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* This maps the generic CLPS711x registers
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*/
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@ -166,8 +167,8 @@ void __init clps711x_init_irq(void)
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static unsigned long clps711x_gettimeoffset(void)
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{
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unsigned long hwticks;
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hwticks = LATCH - (clps_readl(TC2D) & 0xffff); /* since last underflow */
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return (hwticks * (tick_nsec / 1000)) / LATCH;
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hwticks = latch - (clps_readl(TC2D) & 0xffff);
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return (hwticks * (tick_nsec / 1000)) / latch;
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}
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/*
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@ -185,15 +186,71 @@ static struct irqaction clps711x_timer_irq = {
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.handler = p720t_timer_interrupt,
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};
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static void add_fixed_clk(struct clk *clk, const char *name, int rate)
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{
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clk = clk_register_fixed_rate(NULL, name, NULL, CLK_IS_ROOT, rate);
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clk_register_clkdev(clk, name, NULL);
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}
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static void __init clps711x_timer_init(void)
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{
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unsigned int syscon;
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int osc, ext, pll, cpu, bus, timl, timh, uart, spi;
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u32 tmp;
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syscon = clps_readl(SYSCON1);
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syscon |= SYSCON1_TC2S | SYSCON1_TC2M;
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clps_writel(syscon, SYSCON1);
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osc = 3686400;
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ext = 13000000;
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clps_writel(LATCH-1, TC2D); /* 512kHz / 100Hz - 1 */
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tmp = clps_readl(PLLR) >> 24;
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if (tmp)
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pll = (osc * tmp) / 2;
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else
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pll = 73728000; /* Default value */
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tmp = clps_readl(SYSFLG2);
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if (tmp & SYSFLG2_CKMODE) {
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cpu = ext;
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bus = cpu;
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spi = 135400;
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} else {
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cpu = pll;
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if (cpu >= 36864000)
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bus = cpu / 2;
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else
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bus = 36864000 / 2;
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spi = cpu / 576;
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}
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uart = bus / 10;
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if (tmp & SYSFLG2_CKMODE) {
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tmp = clps_readl(SYSCON2);
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if (tmp & SYSCON2_OSTB)
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timh = ext / 26;
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else
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timh = 541440;
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} else
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timh = cpu / 144;
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timl = timh / 256;
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/* All clocks are fixed */
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add_fixed_clk(clk_pll, "pll", pll);
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add_fixed_clk(clk_bus, "bus", bus);
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add_fixed_clk(clk_uart, "uart", uart);
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add_fixed_clk(clk_timerl, "timer_lf", timl);
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add_fixed_clk(clk_timerh, "timer_hf", timh);
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add_fixed_clk(clk_tint, "tint", 64);
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add_fixed_clk(clk_spi, "spi", spi);
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pr_info("CPU frequency set at %i Hz.\n", cpu);
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latch = (timh + HZ / 2) / HZ;
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tmp = clps_readl(SYSCON1);
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tmp |= SYSCON1_TC2S | SYSCON1_TC2M;
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clps_writel(tmp, SYSCON1);
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clps_writel(latch - 1, TC2D);
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setup_irq(IRQ_TC2OI, &clps711x_timer_irq);
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}
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@ -1,23 +1,2 @@
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/*
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* arch/arm/mach-clps711x/include/mach/timex.h
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*
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* Prospector 720T architecture timex specifications
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*
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* Copyright (C) 2000 Deep Blue Solutions Ltd.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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/* Bogus value */
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#define CLOCK_TICK_RATE 512000
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