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authorVipin KUMAR <vipin.kumar@st.com>2010-01-15 19:15:43 +0530
committerTom Rix <Tom.Rix@windriver.com>2010-01-23 08:15:49 -0600
commit81c0ebf623ddbb6a4da8e051441c83e99a01b00b (patch)
tree88511791ad3eb77d078c1e2e5952df5949076c97 /cpu/arm926ejs/spear/timer.c
parent6fffcdf8c869a3d8436be8eff6428d8121aa76e6 (diff)
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SPEAr : Adding basic SPEAr architecture support.
SPEAr Architecture support added. It contains the support for following SPEAr blocks - Timer - System controller - Misc registers Signed-off-by: Vipin <vipin.kumar@st.com>
Diffstat (limited to 'cpu/arm926ejs/spear/timer.c')
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1 files changed, 153 insertions, 0 deletions
diff --git a/cpu/arm926ejs/spear/timer.c b/cpu/arm926ejs/spear/timer.c
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+/*
+ * (C) Copyright 2009
+ * Vipin Kumar, ST Micoelectronics, vipin.kumar@st.com.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/arch/hardware.h>
+#include <asm/arch/spr_gpt.h>
+#include <asm/arch/spr_misc.h>
+
+#define GPT_RESOLUTION (CONFIG_SPEAR_HZ_CLOCK / CONFIG_SPEAR_HZ)
+#define READ_TIMER() (readl(&gpt_regs_p->count) & GPT_FREE_RUNNING)
+
+static struct gpt_regs *const gpt_regs_p =
+ (struct gpt_regs *)CONFIG_SPEAR_TIMERBASE;
+
+static struct misc_regs *const misc_regs_p =
+ (struct misc_regs *)CONFIG_SPEAR_MISCBASE;
+
+static ulong timestamp;
+static ulong lastdec;
+
+int timer_init(void)
+{
+ u32 synth;
+
+ /* Prescaler setting */
+#if defined(CONFIG_SPEAR3XX)
+ writel(MISC_PRSC_CFG, &misc_regs_p->prsc2_clk_cfg);
+ synth = MISC_GPT4SYNTH;
+#elif defined(CONFIG_SPEAR600)
+ writel(MISC_PRSC_CFG, &misc_regs_p->prsc1_clk_cfg);
+ synth = MISC_GPT3SYNTH;
+#else
+# error Incorrect config. Can only be spear{600|300|310|320}
+#endif
+
+ writel(readl(&misc_regs_p->periph_clk_cfg) | synth,
+ &misc_regs_p->periph_clk_cfg);
+
+ /* disable timers */
+ writel(GPT_PRESCALER_1 | GPT_MODE_AUTO_RELOAD, &gpt_regs_p->control);
+
+ /* load value for free running */
+ writel(GPT_FREE_RUNNING, &gpt_regs_p->compare);
+
+ /* auto reload, start timer */
+ writel(readl(&gpt_regs_p->control) | GPT_ENABLE, &gpt_regs_p->control);
+
+ reset_timer_masked();
+
+ return 0;
+}
+
+/*
+ * timer without interrupts
+ */
+
+void reset_timer(void)
+{
+ reset_timer_masked();
+}
+
+ulong get_timer(ulong base)
+{
+ return (get_timer_masked() / GPT_RESOLUTION) - base;
+}
+
+void set_timer(ulong t)
+{
+ timestamp = t;
+}
+
+void __udelay(unsigned long usec)
+{
+ ulong tmo;
+ ulong start = get_timer_masked();
+ ulong tenudelcnt = CONFIG_SPEAR_HZ_CLOCK / (1000 * 100);
+ ulong rndoff;
+
+ rndoff = (usec % 10) ? 1 : 0;
+
+ /* tenudelcnt timer tick gives 10 microsecconds delay */
+ tmo = ((usec / 10) + rndoff) * tenudelcnt;
+
+ while ((ulong) (get_timer_masked() - start) < tmo)
+ ;
+}
+
+void reset_timer_masked(void)
+{
+ /* reset time */
+ lastdec = READ_TIMER();
+ timestamp = 0;
+}
+
+ulong get_timer_masked(void)
+{
+ ulong now = READ_TIMER();
+
+ if (now >= lastdec) {
+ /* normal mode */
+ timestamp += now - lastdec;
+ } else {
+ /* we have an overflow ... */
+ timestamp += now + GPT_FREE_RUNNING - lastdec;
+ }
+ lastdec = now;
+
+ return timestamp;
+}
+
+void udelay_masked(unsigned long usec)
+{
+ return udelay(usec);
+}
+
+/*
+ * This function is derived from PowerPC code (read timebase as long long).
+ * On ARM it just returns the timer value.
+ */
+unsigned long long get_ticks(void)
+{
+ return get_timer(0);
+}
+
+/*
+ * This function is derived from PowerPC code (timebase clock frequency).
+ * On ARM it returns the number of timer ticks per second.
+ */
+ulong get_tbclk(void)
+{
+ return CONFIG_SPEAR_HZ;
+}