diff options
Diffstat (limited to 'arch/arm/mach-pnx4008/time.c')
-rw-r--r-- | arch/arm/mach-pnx4008/time.c | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/arch/arm/mach-pnx4008/time.c b/arch/arm/mach-pnx4008/time.c new file mode 100644 index 000000000000..4ce680698529 --- /dev/null +++ b/arch/arm/mach-pnx4008/time.c | |||
@@ -0,0 +1,141 @@ | |||
1 | /* | ||
2 | * arch/arm/mach-pnx4008/time.c | ||
3 | * | ||
4 | * PNX4008 Timers | ||
5 | * | ||
6 | * Authors: Vitaly Wool, Dmitry Chigirev, Grigory Tolstolytkin <source@mvista.com> | ||
7 | * | ||
8 | * 2005 (c) MontaVista Software, Inc. This file is licensed under | ||
9 | * the terms of the GNU General Public License version 2. This program | ||
10 | * is licensed "as is" without any warranty of any kind, whether express | ||
11 | * or implied. | ||
12 | */ | ||
13 | |||
14 | #include <linux/config.h> | ||
15 | #include <linux/kernel.h> | ||
16 | #include <linux/init.h> | ||
17 | #include <linux/delay.h> | ||
18 | #include <linux/interrupt.h> | ||
19 | #include <linux/sched.h> | ||
20 | #include <linux/spinlock.h> | ||
21 | #include <linux/module.h> | ||
22 | #include <linux/kallsyms.h> | ||
23 | |||
24 | #include <asm/system.h> | ||
25 | #include <asm/hardware.h> | ||
26 | #include <asm/io.h> | ||
27 | #include <asm/leds.h> | ||
28 | #include <asm/irq.h> | ||
29 | #include <asm/mach/irq.h> | ||
30 | #include <asm/mach/time.h> | ||
31 | |||
32 | #include <linux/time.h> | ||
33 | #include <linux/timex.h> | ||
34 | #include <asm/errno.h> | ||
35 | |||
36 | /*! Note: all timers are UPCOUNTING */ | ||
37 | |||
38 | /*! | ||
39 | * Returns number of us since last clock interrupt. Note that interrupts | ||
40 | * will have been disabled by do_gettimeoffset() | ||
41 | */ | ||
42 | static unsigned long pnx4008_gettimeoffset(void) | ||
43 | { | ||
44 | u32 ticks_to_match = | ||
45 | __raw_readl(HSTIM_MATCH0) - __raw_readl(HSTIM_COUNTER); | ||
46 | u32 elapsed = LATCH - ticks_to_match; | ||
47 | return (elapsed * (tick_nsec / 1000)) / LATCH; | ||
48 | } | ||
49 | |||
50 | /*! | ||
51 | * IRQ handler for the timer | ||
52 | */ | ||
53 | static irqreturn_t pnx4008_timer_interrupt(int irq, void *dev_id, | ||
54 | struct pt_regs *regs) | ||
55 | { | ||
56 | if (__raw_readl(HSTIM_INT) & MATCH0_INT) { | ||
57 | |||
58 | write_seqlock(&xtime_lock); | ||
59 | |||
60 | do { | ||
61 | timer_tick(regs); | ||
62 | |||
63 | /* | ||
64 | * this algorithm takes care of possible delay | ||
65 | * for this interrupt handling longer than a normal | ||
66 | * timer period | ||
67 | */ | ||
68 | __raw_writel(__raw_readl(HSTIM_MATCH0) + LATCH, | ||
69 | HSTIM_MATCH0); | ||
70 | __raw_writel(MATCH0_INT, HSTIM_INT); /* clear interrupt */ | ||
71 | |||
72 | /* | ||
73 | * The goal is to keep incrementing HSTIM_MATCH0 | ||
74 | * register until HSTIM_MATCH0 indicates time after | ||
75 | * what HSTIM_COUNTER indicates. | ||
76 | */ | ||
77 | } while ((signed) | ||
78 | (__raw_readl(HSTIM_MATCH0) - | ||
79 | __raw_readl(HSTIM_COUNTER)) < 0); | ||
80 | |||
81 | write_sequnlock(&xtime_lock); | ||
82 | } | ||
83 | |||
84 | return IRQ_HANDLED; | ||
85 | } | ||
86 | |||
87 | static struct irqaction pnx4008_timer_irq = { | ||
88 | .name = "PNX4008 Tick Timer", | ||
89 | .flags = SA_INTERRUPT | SA_TIMER, | ||
90 | .handler = pnx4008_timer_interrupt | ||
91 | }; | ||
92 | |||
93 | /*! | ||
94 | * Set up timer and timer interrupt. | ||
95 | */ | ||
96 | static __init void pnx4008_setup_timer(void) | ||
97 | { | ||
98 | __raw_writel(RESET_COUNT, MSTIM_CTRL); | ||
99 | while (__raw_readl(MSTIM_COUNTER)) ; /* wait for reset to complete. 100% guarantee event */ | ||
100 | __raw_writel(0, MSTIM_CTRL); /* stop the timer */ | ||
101 | __raw_writel(0, MSTIM_MCTRL); | ||
102 | |||
103 | __raw_writel(RESET_COUNT, HSTIM_CTRL); | ||
104 | while (__raw_readl(HSTIM_COUNTER)) ; /* wait for reset to complete. 100% guarantee event */ | ||
105 | __raw_writel(0, HSTIM_CTRL); | ||
106 | __raw_writel(0, HSTIM_MCTRL); | ||
107 | __raw_writel(0, HSTIM_CCR); | ||
108 | __raw_writel(12, HSTIM_PMATCH); /* scale down to 1 MHZ */ | ||
109 | __raw_writel(LATCH, HSTIM_MATCH0); | ||
110 | __raw_writel(MR0_INT, HSTIM_MCTRL); | ||
111 | |||
112 | setup_irq(HSTIMER_INT, &pnx4008_timer_irq); | ||
113 | |||
114 | __raw_writel(COUNT_ENAB | DEBUG_EN, HSTIM_CTRL); /*start timer, stop when JTAG active */ | ||
115 | } | ||
116 | |||
117 | /* Timer Clock Control in PM register */ | ||
118 | #define TIMCLK_CTRL_REG IO_ADDRESS((PNX4008_PWRMAN_BASE + 0xBC)) | ||
119 | #define WATCHDOG_CLK_EN 1 | ||
120 | #define TIMER_CLK_EN 2 /* HS and MS timers? */ | ||
121 | |||
122 | static u32 timclk_ctrl_reg_save; | ||
123 | |||
124 | void pnx4008_timer_suspend(void) | ||
125 | { | ||
126 | timclk_ctrl_reg_save = __raw_readl(TIMCLK_CTRL_REG); | ||
127 | __raw_writel(0, TIMCLK_CTRL_REG); /* disable timers */ | ||
128 | } | ||
129 | |||
130 | void pnx4008_timer_resume(void) | ||
131 | { | ||
132 | __raw_writel(timclk_ctrl_reg_save, TIMCLK_CTRL_REG); /* enable timers */ | ||
133 | } | ||
134 | |||
135 | struct sys_timer pnx4008_timer = { | ||
136 | .init = pnx4008_setup_timer, | ||
137 | .offset = pnx4008_gettimeoffset, | ||
138 | .suspend = pnx4008_timer_suspend, | ||
139 | .resume = pnx4008_timer_resume, | ||
140 | }; | ||
141 | |||