[PATCH 4/4] ARM: clps711x: Added simple clock framework
Alexander Shiyan
shc_work at mail.ru
Tue Aug 21 12:59:35 EDT 2012
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 at mail.ru>
---
arch/arm/Kconfig | 2 +
arch/arm/mach-clps711x/common.c | 89 ++++++++++++++++++++++-----
arch/arm/mach-clps711x/include/mach/timex.h | 23 +-------
3 files changed, 76 insertions(+), 38 deletions(-)
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 6d6e18f..2b23202 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -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.
diff --git a/arch/arm/mach-clps711x/common.c b/arch/arm/mach-clps711x/common.c
index f15293b..5f25ea3 100644
--- a/arch/arm/mach-clps711x/common.c
+++ b/arch/arm/mach-clps711x/common.c
@@ -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;
+
+ osc = 3686400;
+ ext = 13000000;
+
+ 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;
- syscon = clps_readl(SYSCON1);
- syscon |= SYSCON1_TC2S | SYSCON1_TC2M;
- clps_writel(syscon, SYSCON1);
+ tmp = clps_readl(SYSCON1);
+ tmp |= SYSCON1_TC2S | SYSCON1_TC2M;
+ clps_writel(tmp, SYSCON1);
- clps_writel(LATCH-1, TC2D); /* 512kHz / 100Hz - 1 */
+ clps_writel(latch - 1, TC2D);
setup_irq(IRQ_TC2OI, &clps711x_timer_irq);
}
diff --git a/arch/arm/mach-clps711x/include/mach/timex.h b/arch/arm/mach-clps711x/include/mach/timex.h
index ac8823c..de6fd19 100644
--- a/arch/arm/mach-clps711x/include/mach/timex.h
+++ b/arch/arm/mach-clps711x/include/mach/timex.h
@@ -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
--
1.7.8.6
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