1 files changed, 266 insertions, 0 deletions

diff --git a/arch/mips/alchemy/common/time.c b/arch/mips/alchemy/common/time.c
new file mode 100644
index 00000000000..563d9390a87
--- /dev/null
+++ b/arch/mips/alchemy/common/time.c
@@ -0,0 +1,266 @@
+/*
+ *
+ * Copyright (C) 2001, 2006, 2008 MontaVista Software, <source@mvista.com>
+ * Copied and modified Carsten Langgaard's time.c
+ *
+ * Carsten Langgaard, carstenl@mips.com
+ * Copyright (C) 1999,2000 MIPS Technologies, Inc.  All rights reserved.
+ *
+ * ########################################################################
+ *
+ *  This program is free software; you can distribute it and/or modify it
+ *  under the terms of the GNU General Public License (Version 2) as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope 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.
+ *
+ * ########################################################################
+ *
+ * Setting up the clock on the MIPS boards.
+ *
+ * We provide the clock interrupt processing and the timer offset compute
+ * functions.  If CONFIG_PM is selected, we also ensure the 32KHz timer is
+ * available.  -- Dan
+ */
+
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+
+#include <asm/mipsregs.h>
+#include <asm/time.h>
+#include <asm/mach-au1x00/au1000.h>
+
+static int no_au1xxx_32khz;
+extern int allow_au1k_wait; /* default off for CP0 Counter */
+
+#ifdef CONFIG_PM
+#if HZ < 100 || HZ > 1000
+#error "unsupported HZ value! Must be in [100,1000]"
+#endif
+#define MATCH20_INC (328 * 100 / HZ) /* magic number 328 is for HZ=100... */
+static unsigned long last_pc0, last_match20;
+#endif
+
+static DEFINE_SPINLOCK(time_lock);
+
+unsigned long wtimer;
+
+#ifdef CONFIG_PM
+static irqreturn_t counter0_irq(int irq, void *dev_id)
+{
+        unsigned long pc0;
+        int time_elapsed;
+        static int jiffie_drift;
+
+        if (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_M20) {
+                /* should never happen! */
+                printk(KERN_WARNING "counter 0 w status error\n");
+                return IRQ_NONE;
+        }
+
+        pc0 = au_readl(SYS_TOYREAD);
+        if (pc0 < last_match20)
+                /* counter overflowed */
+                time_elapsed = (0xffffffff - last_match20) + pc0;
+        else
+                time_elapsed = pc0 - last_match20;
+
+        while (time_elapsed > 0) {
+                do_timer(1);
+#ifndef CONFIG_SMP
+                update_process_times(user_mode(get_irq_regs()));
+#endif
+                time_elapsed -= MATCH20_INC;
+                last_match20 += MATCH20_INC;
+                jiffie_drift++;
+        }
+
+        last_pc0 = pc0;
+        au_writel(last_match20 + MATCH20_INC, SYS_TOYMATCH2);
+        au_sync();
+
+        /*
+         * Our counter ticks at 10.009765625 ms/tick, we we're running
+         * almost 10 uS too slow per tick.
+         */
+
+        if (jiffie_drift >= 999) {
+                jiffie_drift -= 999;
+                do_timer(1); /* increment jiffies by one */
+#ifndef CONFIG_SMP
+                update_process_times(user_mode(get_irq_regs()));
+#endif
+        }
+
+        return IRQ_HANDLED;
+}
+
+struct irqaction counter0_action = {
+        .handler        = counter0_irq,
+        .flags          = IRQF_DISABLED,
+        .name           = "alchemy-toy",
+        .dev_id         = NULL,
+};
+
+/* When we wakeup from sleep, we have to "catch up" on all of the
+ * timer ticks we have missed.
+ */
+void wakeup_counter0_adjust(void)
+{
+        unsigned long pc0;
+        int time_elapsed;
+
+        pc0 = au_readl(SYS_TOYREAD);
+        if (pc0 < last_match20)
+                /* counter overflowed */
+                time_elapsed = (0xffffffff - last_match20) + pc0;
+        else
+                time_elapsed = pc0 - last_match20;
+
+        while (time_elapsed > 0) {
+                time_elapsed -= MATCH20_INC;
+                last_match20 += MATCH20_INC;
+        }
+
+        last_pc0 = pc0;
+        au_writel(last_match20 + MATCH20_INC, SYS_TOYMATCH2);
+        au_sync();
+
+}
+
+/* This is just for debugging to set the timer for a sleep delay. */
+void wakeup_counter0_set(int ticks)
+{
+        unsigned long pc0;
+
+        pc0 = au_readl(SYS_TOYREAD);
+        last_pc0 = pc0;
+        au_writel(last_match20 + (MATCH20_INC * ticks), SYS_TOYMATCH2);
+        au_sync();
+}
+#endif
+
+/*
+ * I haven't found anyone that doesn't use a 12 MHz source clock,
+ * but just in case.....
+ */
+#define AU1000_SRC_CLK  12000000
+
+/*
+ * We read the real processor speed from the PLL.  This is important
+ * because it is more accurate than computing it from the 32 KHz
+ * counter, if it exists.  If we don't have an accurate processor
+ * speed, all of the peripherals that derive their clocks based on
+ * this advertised speed will introduce error and sometimes not work
+ * properly.  This function is futher convoluted to still allow configurations
+ * to do that in case they have really, really old silicon with a
+ * write-only PLL register, that we need the 32 KHz when power management
+ * "wait" is enabled, and we need to detect if the 32 KHz isn't present
+ * but requested......got it? :-)               -- Dan
+ */
+unsigned long calc_clock(void)
+{
+        unsigned long cpu_speed;
+        unsigned long flags;
+        unsigned long counter;
+
+        spin_lock_irqsave(&time_lock, flags);
+
+        /* Power management cares if we don't have a 32 KHz counter. */
+        no_au1xxx_32khz = 0;
+        counter = au_readl(SYS_COUNTER_CNTRL);
+        if (counter & SYS_CNTRL_E0) {
+                int trim_divide = 16;
+
+                au_writel(counter | SYS_CNTRL_EN1, SYS_COUNTER_CNTRL);
+
+                while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_T1S);
+                /* RTC now ticks at 32.768/16 kHz */
+                au_writel(trim_divide - 1, SYS_RTCTRIM);
+                while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_T1S);
+
+                while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_C1S);
+                au_writel(0, SYS_TOYWRITE);
+                while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_C1S);
+        } else
+                no_au1xxx_32khz = 1;
+
+        /*
+         * On early Au1000, sys_cpupll was write-only. Since these
+         * silicon versions of Au1000 are not sold by AMD, we don't bend
+         * over backwards trying to determine the frequency.
+         */
+        if (cur_cpu_spec[0]->cpu_pll_wo)
+#ifdef CONFIG_SOC_AU1000_FREQUENCY
+                cpu_speed = CONFIG_SOC_AU1000_FREQUENCY;
+#else
+                cpu_speed = 396000000;
+#endif
+        else
+                cpu_speed = (au_readl(SYS_CPUPLL) & 0x0000003f) * AU1000_SRC_CLK;
+        /* On Alchemy CPU:counter ratio is 1:1 */
+        mips_hpt_frequency = cpu_speed;
+        /* Equation: Baudrate = CPU / (SD * 2 * CLKDIV * 16) */
+        set_au1x00_uart_baud_base(cpu_speed / (2 * ((int)(au_readl(SYS_POWERCTRL)
+                                                          & 0x03) + 2) * 16));
+        spin_unlock_irqrestore(&time_lock, flags);
+        return cpu_speed;
+}
+
+void __init plat_time_init(void)
+{
+        unsigned int est_freq = calc_clock();
+
+        est_freq += 5000;    /* round */
+        est_freq -= est_freq%10000;
+        printk(KERN_INFO "CPU frequency %u.%02u MHz\n",
+               est_freq / 1000000, ((est_freq % 1000000) * 100) / 1000000);
+        set_au1x00_speed(est_freq);
+        set_au1x00_lcd_clock(); /* program the LCD clock */
+
+#ifdef CONFIG_PM
+        /*
+         * setup counter 0, since it keeps ticking after a
+         * 'wait' instruction has been executed. The CP0 timer and
+         * counter 1 do NOT continue running after 'wait'
+         *
+         * It's too early to call request_irq() here, so we handle
+         * counter 0 interrupt as a special irq and it doesn't show
+         * up under /proc/interrupts.
+         *
+         * Check to ensure we really have a 32 KHz oscillator before
+         * we do this.
+         */
+        if (no_au1xxx_32khz)
+                printk(KERN_WARNING "WARNING: no 32KHz clock found.\n");
+        else {
+                while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_C0S);
+                au_writel(0, SYS_TOYWRITE);
+                while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_C0S);
+
+                au_writel(au_readl(SYS_WAKEMSK) | (1 << 8), SYS_WAKEMSK);
+                au_writel(~0, SYS_WAKESRC);
+                au_sync();
+                while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_M20);
+
+                /* Setup match20 to interrupt once every HZ */
+                last_pc0 = last_match20 = au_readl(SYS_TOYREAD);
+                au_writel(last_match20 + MATCH20_INC, SYS_TOYMATCH2);
+                au_sync();
+                while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_M20);
+                setup_irq(AU1000_TOY_MATCH2_INT, &counter0_action);
+
+                /* We can use the real 'wait' instruction. */
+                allow_au1k_wait = 1;
+        }
+
+#endif
+}