2 * linux/arch/arm/mach-clps711x/core.c
4 * Core support for the CLPS711x-based machines.
6 * Copyright (C) 2001,2011 Deep Blue Solutions Ltd
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (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, MA 02111-1307 USA
23 #include <linux/init.h>
24 #include <linux/sizes.h>
25 #include <linux/interrupt.h>
26 #include <linux/irq.h>
27 #include <linux/clk.h>
28 #include <linux/clkdev.h>
29 #include <linux/clockchips.h>
30 #include <linux/clocksource.h>
31 #include <linux/clk-provider.h>
32 #include <linux/sched_clock.h>
34 #include <asm/mach/map.h>
35 #include <asm/mach/time.h>
36 #include <asm/system_misc.h>
38 #include <mach/hardware.h>
42 static struct clk
*clk_pll
, *clk_bus
, *clk_uart
, *clk_timerl
, *clk_timerh
,
46 * This maps the generic CLPS711x registers
48 static struct map_desc clps711x_io_desc
[] __initdata
= {
50 .virtual = (unsigned long)CLPS711X_VIRT_BASE
,
51 .pfn
= __phys_to_pfn(CLPS711X_PHYS_BASE
),
57 void __init
clps711x_map_io(void)
59 iotable_init(clps711x_io_desc
, ARRAY_SIZE(clps711x_io_desc
));
62 void __init
clps711x_init_irq(void)
64 clps711x_intc_init(CLPS711X_PHYS_BASE
, SZ_16K
);
67 static u64 notrace
clps711x_sched_clock_read(void)
69 return ~readw_relaxed(CLPS711X_VIRT_BASE
+ TC1D
);
72 static void clps711x_clockevent_set_mode(enum clock_event_mode mode
,
73 struct clock_event_device
*evt
)
75 disable_irq(IRQ_TC2OI
);
78 case CLOCK_EVT_MODE_PERIODIC
:
79 enable_irq(IRQ_TC2OI
);
81 case CLOCK_EVT_MODE_ONESHOT
:
83 case CLOCK_EVT_MODE_SHUTDOWN
:
84 case CLOCK_EVT_MODE_UNUSED
:
85 case CLOCK_EVT_MODE_RESUME
:
86 /* Left event sources disabled, no more interrupts appear */
91 static struct clock_event_device clockevent_clps711x
= {
92 .name
= "clps711x-clockevent",
94 .features
= CLOCK_EVT_FEAT_PERIODIC
,
95 .set_mode
= clps711x_clockevent_set_mode
,
98 static irqreturn_t
clps711x_timer_interrupt(int irq
, void *dev_id
)
100 clockevent_clps711x
.event_handler(&clockevent_clps711x
);
105 static struct irqaction clps711x_timer_irq
= {
106 .name
= "clps711x-timer",
107 .flags
= IRQF_TIMER
| IRQF_IRQPOLL
,
108 .handler
= clps711x_timer_interrupt
,
111 static void add_fixed_clk(struct clk
*clk
, const char *name
, int rate
)
113 clk
= clk_register_fixed_rate(NULL
, name
, NULL
, CLK_IS_ROOT
, rate
);
114 clk_register_clkdev(clk
, name
, NULL
);
117 void __init
clps711x_timer_init(void)
119 int osc
, ext
, pll
, cpu
, bus
, timl
, timh
, uart
, spi
;
125 tmp
= clps_readl(PLLR
) >> 24;
127 pll
= (osc
* tmp
) / 2;
129 pll
= 73728000; /* Default value */
131 tmp
= clps_readl(SYSFLG2
);
132 if (tmp
& SYSFLG2_CKMODE
) {
148 if (tmp
& SYSFLG2_CKMODE
) {
149 tmp
= clps_readl(SYSCON2
);
150 if (tmp
& SYSCON2_OSTB
)
155 timh
= DIV_ROUND_CLOSEST(cpu
, 144);
157 timl
= DIV_ROUND_CLOSEST(timh
, 256);
159 /* All clocks are fixed */
160 add_fixed_clk(clk_pll
, "pll", pll
);
161 add_fixed_clk(clk_bus
, "bus", bus
);
162 add_fixed_clk(clk_uart
, "uart", uart
);
163 add_fixed_clk(clk_timerl
, "timer_lf", timl
);
164 add_fixed_clk(clk_timerh
, "timer_hf", timh
);
165 add_fixed_clk(clk_tint
, "tint", 64);
166 add_fixed_clk(clk_spi
, "spi", spi
);
168 pr_info("CPU frequency set at %i Hz.\n", cpu
);
170 /* Start Timer1 in free running mode (Low frequency) */
171 tmp
= clps_readl(SYSCON1
) & ~(SYSCON1_TC1S
| SYSCON1_TC1M
);
172 clps_writel(tmp
, SYSCON1
);
174 sched_clock_register(clps711x_sched_clock_read
, 16, timl
);
176 clocksource_mmio_init(CLPS711X_VIRT_BASE
+ TC1D
,
177 "clps711x_clocksource", timl
, 300, 16,
178 clocksource_mmio_readw_down
);
180 /* Set Timer2 prescaler */
181 clps_writew(DIV_ROUND_CLOSEST(timh
, HZ
), TC2D
);
183 /* Start Timer2 in prescale mode (High frequency)*/
184 tmp
= clps_readl(SYSCON1
) | SYSCON1_TC2M
| SYSCON1_TC2S
;
185 clps_writel(tmp
, SYSCON1
);
187 clockevents_config_and_register(&clockevent_clps711x
, timh
, 0, 0);
189 setup_irq(IRQ_TC2OI
, &clps711x_timer_irq
);
192 void clps711x_restart(enum reboot_mode mode
, const char *cmd
)
197 static void clps711x_idle(void)
199 clps_writel(1, HALT
);
204 void __init
clps711x_init_early(void)
206 arm_pm_idle
= clps711x_idle
;