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>

2 files changed, 74 insertions, 38 deletions

diff --git a/arch/arm/mach-clps711x/common.c b/arch/arm/mach-clps711x/common.c
index f15293bd797..509243d89a3 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 ac8823ccff9..de6fd192d1c 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