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 DECLARE_GLOBAL_DATA_PTR;
41 #define timestamp gd->arch.tbl
42 #define lastdec gd->arch.lastinc
48 /* Prescaler setting */
49 #if defined(CONFIG_SPEAR3XX)
50 writel(MISC_PRSC_CFG, &misc_regs_p->prsc2_clk_cfg);
51 synth = MISC_GPT4SYNTH;
52 #elif defined(CONFIG_SPEAR600)
53 writel(MISC_PRSC_CFG, &misc_regs_p->prsc1_clk_cfg);
54 synth = MISC_GPT3SYNTH;
56 # error Incorrect config. Can only be spear{600|300|310|320}
59 writel(readl(&misc_regs_p->periph_clk_cfg) | synth,
60 &misc_regs_p->periph_clk_cfg);
63 writel(GPT_PRESCALER_1 | GPT_MODE_AUTO_RELOAD, &gpt_regs_p->control);
65 /* load value for free running */
66 writel(GPT_FREE_RUNNING, &gpt_regs_p->compare);
68 /* auto reload, start timer */
69 writel(readl(&gpt_regs_p->control) | GPT_ENABLE, &gpt_regs_p->control);
72 lastdec = READ_TIMER();
79 * timer without interrupts
81 ulong get_timer(ulong base)
83 return (get_timer_masked() / GPT_RESOLUTION) - base;
86 void __udelay(unsigned long usec)
89 ulong start = get_timer_masked();
90 ulong tenudelcnt = CONFIG_SPEAR_HZ_CLOCK / (1000 * 100);
93 rndoff = (usec % 10) ? 1 : 0;
95 /* tenudelcnt timer tick gives 10 microsecconds delay */
96 tmo = ((usec / 10) + rndoff) * tenudelcnt;
98 while ((ulong) (get_timer_masked() - start) < tmo)
102 ulong get_timer_masked(void)
104 ulong now = READ_TIMER();
106 if (now >= lastdec) {
108 timestamp += now - lastdec;
110 /* we have an overflow ... */
111 timestamp += now + GPT_FREE_RUNNING - lastdec;
118 void udelay_masked(unsigned long usec)
124 * This function is derived from PowerPC code (read timebase as long long).
125 * On ARM it just returns the timer value.
127 unsigned long long get_ticks(void)
133 * This function is derived from PowerPC code (timebase clock frequency).
134 * On ARM it returns the number of timer ticks per second.
136 ulong get_tbclk(void)
138 return CONFIG_SPEAR_HZ;