Merge branch 'clk/mxs-for-3.6' of git://git.linaro.org/people/shawnguo/linux-2.6...
[deliverable/linux.git] / arch / arm / plat-mxc / time.c
CommitLineData
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1/*
2 * linux/arch/arm/plat-mxc/time.c
3 *
4 * Copyright (C) 2000-2001 Deep Blue Solutions
5 * Copyright (C) 2002 Shane Nay (shane@minirl.com)
6 * Copyright (C) 2006-2007 Pavel Pisa (ppisa@pikron.com)
7 * Copyright (C) 2008 Juergen Beisert (kernel@pengutronix.de)
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * as published by the Free Software Foundation; either version 2
12 * of 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.
17 *
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., 51 Franklin Street, Fifth Floor, Boston,
21 * MA 02110-1301, USA.
22 */
23
24#include <linux/interrupt.h>
25#include <linux/irq.h>
26#include <linux/clockchips.h>
27#include <linux/clk.h>
821dc4df 28#include <linux/err.h>
d0f349fb 29
a09e64fb 30#include <mach/hardware.h>
c124befc 31#include <asm/sched_clock.h>
d0f349fb 32#include <asm/mach/time.h>
a09e64fb 33#include <mach/common.h>
ec996ba9 34
0f3332c4
SH
35/*
36 * There are 2 versions of the timer hardware on Freescale MXC hardware.
37 * Version 1: MX1/MXL, MX21, MX27.
38 * Version 2: MX25, MX31, MX35, MX37, MX51
39 */
40
ec996ba9
SH
41/* defines common for all i.MX */
42#define MXC_TCTL 0x00
0f3332c4 43#define MXC_TCTL_TEN (1 << 0) /* Enable module */
ec996ba9
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44#define MXC_TPRER 0x04
45
46/* MX1, MX21, MX27 */
47#define MX1_2_TCTL_CLK_PCLK1 (1 << 1)
48#define MX1_2_TCTL_IRQEN (1 << 4)
49#define MX1_2_TCTL_FRR (1 << 8)
50#define MX1_2_TCMP 0x08
51#define MX1_2_TCN 0x10
52#define MX1_2_TSTAT 0x14
53
54/* MX21, MX27 */
55#define MX2_TSTAT_CAPT (1 << 1)
56#define MX2_TSTAT_COMP (1 << 0)
57
13cf8df9 58/* MX31, MX35, MX25, MX5 */
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59#define V2_TCTL_WAITEN (1 << 3) /* Wait enable mode */
60#define V2_TCTL_CLK_IPG (1 << 6)
1f152b48 61#define V2_TCTL_CLK_PER (2 << 6)
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62#define V2_TCTL_FRR (1 << 9)
63#define V2_IR 0x0c
64#define V2_TSTAT 0x08
65#define V2_TSTAT_OF1 (1 << 0)
66#define V2_TCN 0x24
67#define V2_TCMP 0x10
d0f349fb 68
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SH
69#define timer_is_v1() (cpu_is_mx1() || cpu_is_mx21() || cpu_is_mx27())
70#define timer_is_v2() (!timer_is_v1())
71
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72static struct clock_event_device clockevent_mxc;
73static enum clock_event_mode clockevent_mode = CLOCK_EVT_MODE_UNUSED;
74
ec996ba9 75static void __iomem *timer_base;
d0f349fb 76
ec996ba9 77static inline void gpt_irq_disable(void)
d0f349fb 78{
ec996ba9
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79 unsigned int tmp;
80
0f3332c4 81 if (timer_is_v2())
38a66f51 82 __raw_writel(0, timer_base + V2_IR);
ec996ba9
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83 else {
84 tmp = __raw_readl(timer_base + MXC_TCTL);
85 __raw_writel(tmp & ~MX1_2_TCTL_IRQEN, timer_base + MXC_TCTL);
86 }
87}
88
89static inline void gpt_irq_enable(void)
90{
0f3332c4 91 if (timer_is_v2())
38a66f51 92 __raw_writel(1<<0, timer_base + V2_IR);
ec996ba9
SH
93 else {
94 __raw_writel(__raw_readl(timer_base + MXC_TCTL) | MX1_2_TCTL_IRQEN,
95 timer_base + MXC_TCTL);
96 }
97}
98
99static void gpt_irq_acknowledge(void)
100{
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101 if (timer_is_v1()) {
102 if (cpu_is_mx1())
103 __raw_writel(0, timer_base + MX1_2_TSTAT);
104 else
105 __raw_writel(MX2_TSTAT_CAPT | MX2_TSTAT_COMP,
106 timer_base + MX1_2_TSTAT);
107 } else if (timer_is_v2())
d943f2c8 108 __raw_writel(V2_TSTAT_OF1, timer_base + V2_TSTAT);
ec996ba9
SH
109}
110
234b6ced 111static void __iomem *sched_clock_reg;
d0f349fb 112
2f0778af 113static u32 notrace mxc_read_sched_clock(void)
c124befc 114{
2f0778af 115 return sched_clock_reg ? __raw_readl(sched_clock_reg) : 0;
c124befc
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116}
117
30c730f8 118static int __init mxc_clocksource_init(struct clk *timer_clk)
d0f349fb 119{
058b7a6f 120 unsigned int c = clk_get_rate(timer_clk);
234b6ced 121 void __iomem *reg = timer_base + (timer_is_v2() ? V2_TCN : MX1_2_TCN);
d0f349fb 122
234b6ced 123 sched_clock_reg = reg;
ec996ba9 124
2f0778af 125 setup_sched_clock(mxc_read_sched_clock, 32, c);
234b6ced
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126 return clocksource_mmio_init(reg, "mxc_timer1", c, 200, 32,
127 clocksource_mmio_readl_up);
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128}
129
130/* clock event */
131
ec996ba9 132static int mx1_2_set_next_event(unsigned long evt,
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133 struct clock_event_device *unused)
134{
135 unsigned long tcmp;
136
ec996ba9 137 tcmp = __raw_readl(timer_base + MX1_2_TCN) + evt;
d0f349fb 138
ec996ba9
SH
139 __raw_writel(tcmp, timer_base + MX1_2_TCMP);
140
141 return (int)(tcmp - __raw_readl(timer_base + MX1_2_TCN)) < 0 ?
142 -ETIME : 0;
143}
144
38a66f51 145static int v2_set_next_event(unsigned long evt,
ec996ba9
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146 struct clock_event_device *unused)
147{
148 unsigned long tcmp;
149
38a66f51 150 tcmp = __raw_readl(timer_base + V2_TCN) + evt;
ec996ba9 151
38a66f51 152 __raw_writel(tcmp, timer_base + V2_TCMP);
ec996ba9 153
38a66f51 154 return (int)(tcmp - __raw_readl(timer_base + V2_TCN)) < 0 ?
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155 -ETIME : 0;
156}
157
158#ifdef DEBUG
159static const char *clock_event_mode_label[] = {
160 [CLOCK_EVT_MODE_PERIODIC] = "CLOCK_EVT_MODE_PERIODIC",
161 [CLOCK_EVT_MODE_ONESHOT] = "CLOCK_EVT_MODE_ONESHOT",
162 [CLOCK_EVT_MODE_SHUTDOWN] = "CLOCK_EVT_MODE_SHUTDOWN",
163 [CLOCK_EVT_MODE_UNUSED] = "CLOCK_EVT_MODE_UNUSED"
164};
165#endif /* DEBUG */
166
167static void mxc_set_mode(enum clock_event_mode mode,
168 struct clock_event_device *evt)
169{
170 unsigned long flags;
171
172 /*
173 * The timer interrupt generation is disabled at least
174 * for enough time to call mxc_set_next_event()
175 */
176 local_irq_save(flags);
177
178 /* Disable interrupt in GPT module */
179 gpt_irq_disable();
180
181 if (mode != clockevent_mode) {
182 /* Set event time into far-far future */
0f3332c4 183 if (timer_is_v2())
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184 __raw_writel(__raw_readl(timer_base + V2_TCN) - 3,
185 timer_base + V2_TCMP);
ec996ba9
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186 else
187 __raw_writel(__raw_readl(timer_base + MX1_2_TCN) - 3,
188 timer_base + MX1_2_TCMP);
189
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190 /* Clear pending interrupt */
191 gpt_irq_acknowledge();
192 }
193
194#ifdef DEBUG
195 printk(KERN_INFO "mxc_set_mode: changing mode from %s to %s\n",
196 clock_event_mode_label[clockevent_mode],
197 clock_event_mode_label[mode]);
198#endif /* DEBUG */
199
200 /* Remember timer mode */
201 clockevent_mode = mode;
202 local_irq_restore(flags);
203
204 switch (mode) {
205 case CLOCK_EVT_MODE_PERIODIC:
206 printk(KERN_ERR"mxc_set_mode: Periodic mode is not "
207 "supported for i.MX\n");
208 break;
209 case CLOCK_EVT_MODE_ONESHOT:
210 /*
211 * Do not put overhead of interrupt enable/disable into
212 * mxc_set_next_event(), the core has about 4 minutes
213 * to call mxc_set_next_event() or shutdown clock after
214 * mode switching
215 */
216 local_irq_save(flags);
217 gpt_irq_enable();
218 local_irq_restore(flags);
219 break;
220 case CLOCK_EVT_MODE_SHUTDOWN:
221 case CLOCK_EVT_MODE_UNUSED:
222 case CLOCK_EVT_MODE_RESUME:
223 /* Left event sources disabled, no more interrupts appear */
224 break;
225 }
226}
227
228/*
229 * IRQ handler for the timer
230 */
231static irqreturn_t mxc_timer_interrupt(int irq, void *dev_id)
232{
233 struct clock_event_device *evt = &clockevent_mxc;
234 uint32_t tstat;
235
0f3332c4 236 if (timer_is_v2())
38a66f51 237 tstat = __raw_readl(timer_base + V2_TSTAT);
81ec1f92
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238 else
239 tstat = __raw_readl(timer_base + MX1_2_TSTAT);
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240
241 gpt_irq_acknowledge();
242
243 evt->event_handler(evt);
244
245 return IRQ_HANDLED;
246}
247
248static struct irqaction mxc_timer_irq = {
249 .name = "i.MX Timer Tick",
250 .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
251 .handler = mxc_timer_interrupt,
252};
253
254static struct clock_event_device clockevent_mxc = {
255 .name = "mxc_timer1",
256 .features = CLOCK_EVT_FEAT_ONESHOT,
257 .shift = 32,
258 .set_mode = mxc_set_mode,
ec996ba9 259 .set_next_event = mx1_2_set_next_event,
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260 .rating = 200,
261};
262
30c730f8 263static int __init mxc_clockevent_init(struct clk *timer_clk)
d0f349fb 264{
058b7a6f 265 unsigned int c = clk_get_rate(timer_clk);
d0f349fb 266
0f3332c4 267 if (timer_is_v2())
38a66f51 268 clockevent_mxc.set_next_event = v2_set_next_event;
ec996ba9 269
058b7a6f 270 clockevent_mxc.mult = div_sc(c, NSEC_PER_SEC,
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271 clockevent_mxc.shift);
272 clockevent_mxc.max_delta_ns =
273 clockevent_delta2ns(0xfffffffe, &clockevent_mxc);
274 clockevent_mxc.min_delta_ns =
275 clockevent_delta2ns(0xff, &clockevent_mxc);
276
320ab2b0 277 clockevent_mxc.cpumask = cpumask_of(0);
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278
279 clockevents_register_device(&clockevent_mxc);
280
281 return 0;
282}
283
2cfb4518 284void __init mxc_timer_init(void __iomem *base, int irq)
d0f349fb 285{
ec996ba9 286 uint32_t tctl_val;
2cfb4518 287 struct clk *timer_clk;
821dc4df
SH
288 struct clk *timer_ipg_clk;
289
2cfb4518
SH
290 timer_clk = clk_get_sys("imx-gpt.0", "per");
291 if (IS_ERR(timer_clk)) {
292 pr_err("i.MX timer: unable to get clk\n");
293 return;
821dc4df 294 }
ec996ba9 295
2cfb4518
SH
296 timer_ipg_clk = clk_get_sys("imx-gpt.0", "ipg");
297 if (!IS_ERR(timer_ipg_clk))
298 clk_prepare_enable(timer_ipg_clk);
299
46f417de 300 clk_prepare_enable(timer_clk);
d0f349fb 301
8db5d1a6 302 timer_base = base;
ec996ba9 303
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304 /*
305 * Initialise to a known state (all timers off, and timing reset)
306 */
d0f349fb 307
ec996ba9
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308 __raw_writel(0, timer_base + MXC_TCTL);
309 __raw_writel(0, timer_base + MXC_TPRER); /* see datasheet note */
310
0f3332c4 311 if (timer_is_v2())
1f152b48 312 tctl_val = V2_TCTL_CLK_PER | V2_TCTL_FRR | V2_TCTL_WAITEN | MXC_TCTL_TEN;
ec996ba9
SH
313 else
314 tctl_val = MX1_2_TCTL_FRR | MX1_2_TCTL_CLK_PCLK1 | MXC_TCTL_TEN;
315
316 __raw_writel(tctl_val, timer_base + MXC_TCTL);
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317
318 /* init and register the timer to the framework */
30c730f8
SH
319 mxc_clocksource_init(timer_clk);
320 mxc_clockevent_init(timer_clk);
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321
322 /* Make irqs happen */
ec996ba9 323 setup_irq(irq, &mxc_timer_irq);
d0f349fb 324}
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