3 * Vipin Kumar, ST Micoelectronics, vipin.kumar@st.com.
5 * See file CREDITS for list of people who contributed to this
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License as
10 * published by the Free Software Foundation; either version 2 of
11 * the License, or (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
26 #include <asm/arch/hardware.h>
27 #include <asm/arch/spr_gpt.h>
28 #include <asm/arch/spr_misc.h>
30 #define GPT_RESOLUTION (CONFIG_SPEAR_HZ_CLOCK / CONFIG_SPEAR_HZ)
31 #define READ_TIMER() (readl(&gpt_regs_p->count) & GPT_FREE_RUNNING)
33 static struct gpt_regs *const gpt_regs_p =
34 (struct gpt_regs *)CONFIG_SPEAR_TIMERBASE;
36 static struct misc_regs *const misc_regs_p =
37 (struct misc_regs *)CONFIG_SPEAR_MISCBASE;
39 static ulong timestamp;
46 /* Prescaler setting */
47 #if defined(CONFIG_SPEAR3XX)
48 writel(MISC_PRSC_CFG, &misc_regs_p->prsc2_clk_cfg);
49 synth = MISC_GPT4SYNTH;
50 #elif defined(CONFIG_SPEAR600)
51 writel(MISC_PRSC_CFG, &misc_regs_p->prsc1_clk_cfg);
52 synth = MISC_GPT3SYNTH;
54 # error Incorrect config. Can only be spear{600|300|310|320}
57 writel(readl(&misc_regs_p->periph_clk_cfg) | synth,
58 &misc_regs_p->periph_clk_cfg);
61 writel(GPT_PRESCALER_1 | GPT_MODE_AUTO_RELOAD, &gpt_regs_p->control);
63 /* load value for free running */
64 writel(GPT_FREE_RUNNING, &gpt_regs_p->compare);
66 /* auto reload, start timer */
67 writel(readl(&gpt_regs_p->control) | GPT_ENABLE, &gpt_regs_p->control);
75 * timer without interrupts
78 void reset_timer(void)
83 ulong get_timer(ulong base)
85 return (get_timer_masked() / GPT_RESOLUTION) - base;
88 void set_timer(ulong t)
93 void __udelay(unsigned long usec)
96 ulong start = get_timer_masked();
97 ulong tenudelcnt = CONFIG_SPEAR_HZ_CLOCK / (1000 * 100);
100 rndoff = (usec % 10) ? 1 : 0;
102 /* tenudelcnt timer tick gives 10 microsecconds delay */
103 tmo = ((usec / 10) + rndoff) * tenudelcnt;
105 while ((ulong) (get_timer_masked() - start) < tmo)
109 void reset_timer_masked(void)
112 lastdec = READ_TIMER();
116 ulong get_timer_masked(void)
118 ulong now = READ_TIMER();
120 if (now >= lastdec) {
122 timestamp += now - lastdec;
124 /* we have an overflow ... */
125 timestamp += now + GPT_FREE_RUNNING - lastdec;
132 void udelay_masked(unsigned long usec)
138 * This function is derived from PowerPC code (read timebase as long long).
139 * On ARM it just returns the timer value.
141 unsigned long long get_ticks(void)
147 * This function is derived from PowerPC code (timebase clock frequency).
148 * On ARM it returns the number of timer ticks per second.
150 ulong get_tbclk(void)
152 return CONFIG_SPEAR_HZ;