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authorArnd Bergmann <arnd@arndb.de>2012-01-09 12:06:36 -0500
committerArnd Bergmann <arnd@arndb.de>2012-01-09 12:06:36 -0500
commit421b759b86eb8a914cbbd11f6d09a74f411762c6 (patch)
tree505ca7f23987d8eaaa519a7e8506b854e2c0d030 /arch/arm/kernel/smp_twd.c
parente067096c8d57d191f29d734cd5692695c95cc36e (diff)
parenta07613a54d700a974f3a4a657da78ef5d097315d (diff)
Merge branch 'samsung/cleanup' into next/boards
Conflicts: arch/arm/mach-imx/mach-imx6q.c arch/arm/mach-omap2/board-ti8168evm.c arch/arm/mach-s3c64xx/Kconfig arch/arm/mach-tegra/Makefile arch/arm/mach-tegra/board-dt-tegra20.c arch/arm/mach-tegra/common.c Lots of relatively simple conflicts between the board changes and stuff from the arm tree. This pulls in the resolution from the samsung/cleanup tree, so we don't get conflicting merges. Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'arch/arm/kernel/smp_twd.c')
-rw-r--r--arch/arm/kernel/smp_twd.c95
1 files changed, 88 insertions, 7 deletions
diff --git a/arch/arm/kernel/smp_twd.c b/arch/arm/kernel/smp_twd.c
index a8a6682d6b5..c8e938553d4 100644
--- a/arch/arm/kernel/smp_twd.c
+++ b/arch/arm/kernel/smp_twd.c
@@ -10,8 +10,11 @@
10 */ 10 */
11#include <linux/init.h> 11#include <linux/init.h>
12#include <linux/kernel.h> 12#include <linux/kernel.h>
13#include <linux/clk.h>
14#include <linux/cpufreq.h>
13#include <linux/delay.h> 15#include <linux/delay.h>
14#include <linux/device.h> 16#include <linux/device.h>
17#include <linux/err.h>
15#include <linux/smp.h> 18#include <linux/smp.h>
16#include <linux/jiffies.h> 19#include <linux/jiffies.h>
17#include <linux/clockchips.h> 20#include <linux/clockchips.h>
@@ -25,6 +28,7 @@
25/* set up by the platform code */ 28/* set up by the platform code */
26void __iomem *twd_base; 29void __iomem *twd_base;
27 30
31static struct clk *twd_clk;
28static unsigned long twd_timer_rate; 32static unsigned long twd_timer_rate;
29 33
30static struct clock_event_device __percpu **twd_evt; 34static struct clock_event_device __percpu **twd_evt;
@@ -89,6 +93,52 @@ void twd_timer_stop(struct clock_event_device *clk)
89 disable_percpu_irq(clk->irq); 93 disable_percpu_irq(clk->irq);
90} 94}
91 95
96#ifdef CONFIG_CPU_FREQ
97
98/*
99 * Updates clockevent frequency when the cpu frequency changes.
100 * Called on the cpu that is changing frequency with interrupts disabled.
101 */
102static void twd_update_frequency(void *data)
103{
104 twd_timer_rate = clk_get_rate(twd_clk);
105
106 clockevents_update_freq(*__this_cpu_ptr(twd_evt), twd_timer_rate);
107}
108
109static int twd_cpufreq_transition(struct notifier_block *nb,
110 unsigned long state, void *data)
111{
112 struct cpufreq_freqs *freqs = data;
113
114 /*
115 * The twd clock events must be reprogrammed to account for the new
116 * frequency. The timer is local to a cpu, so cross-call to the
117 * changing cpu.
118 */
119 if (state == CPUFREQ_POSTCHANGE || state == CPUFREQ_RESUMECHANGE)
120 smp_call_function_single(freqs->cpu, twd_update_frequency,
121 NULL, 1);
122
123 return NOTIFY_OK;
124}
125
126static struct notifier_block twd_cpufreq_nb = {
127 .notifier_call = twd_cpufreq_transition,
128};
129
130static int twd_cpufreq_init(void)
131{
132 if (!IS_ERR(twd_clk))
133 return cpufreq_register_notifier(&twd_cpufreq_nb,
134 CPUFREQ_TRANSITION_NOTIFIER);
135
136 return 0;
137}
138core_initcall(twd_cpufreq_init);
139
140#endif
141
92static void __cpuinit twd_calibrate_rate(void) 142static void __cpuinit twd_calibrate_rate(void)
93{ 143{
94 unsigned long count; 144 unsigned long count;
@@ -140,6 +190,35 @@ static irqreturn_t twd_handler(int irq, void *dev_id)
140 return IRQ_NONE; 190 return IRQ_NONE;
141} 191}
142 192
193static struct clk *twd_get_clock(void)
194{
195 struct clk *clk;
196 int err;
197
198 clk = clk_get_sys("smp_twd", NULL);
199 if (IS_ERR(clk)) {
200 pr_err("smp_twd: clock not found: %d\n", (int)PTR_ERR(clk));
201 return clk;
202 }
203
204 err = clk_prepare(clk);
205 if (err) {
206 pr_err("smp_twd: clock failed to prepare: %d\n", err);
207 clk_put(clk);
208 return ERR_PTR(err);
209 }
210
211 err = clk_enable(clk);
212 if (err) {
213 pr_err("smp_twd: clock failed to enable: %d\n", err);
214 clk_unprepare(clk);
215 clk_put(clk);
216 return ERR_PTR(err);
217 }
218
219 return clk;
220}
221
143/* 222/*
144 * Setup the local clock events for a CPU. 223 * Setup the local clock events for a CPU.
145 */ 224 */
@@ -165,7 +244,13 @@ void __cpuinit twd_timer_setup(struct clock_event_device *clk)
165 } 244 }
166 } 245 }
167 246
168 twd_calibrate_rate(); 247 if (!twd_clk)
248 twd_clk = twd_get_clock();
249
250 if (!IS_ERR_OR_NULL(twd_clk))
251 twd_timer_rate = clk_get_rate(twd_clk);
252 else
253 twd_calibrate_rate();
169 254
170 clk->name = "local_timer"; 255 clk->name = "local_timer";
171 clk->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT | 256 clk->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT |
@@ -173,15 +258,11 @@ void __cpuinit twd_timer_setup(struct clock_event_device *clk)
173 clk->rating = 350; 258 clk->rating = 350;
174 clk->set_mode = twd_set_mode; 259 clk->set_mode = twd_set_mode;
175 clk->set_next_event = twd_set_next_event; 260 clk->set_next_event = twd_set_next_event;
176 clk->shift = 20;
177 clk->mult = div_sc(twd_timer_rate, NSEC_PER_SEC, clk->shift);
178 clk->max_delta_ns = clockevent_delta2ns(0xffffffff, clk);
179 clk->min_delta_ns = clockevent_delta2ns(0xf, clk);
180 261
181 this_cpu_clk = __this_cpu_ptr(twd_evt); 262 this_cpu_clk = __this_cpu_ptr(twd_evt);
182 *this_cpu_clk = clk; 263 *this_cpu_clk = clk;
183 264
184 clockevents_register_device(clk); 265 clockevents_config_and_register(clk, twd_timer_rate,
185 266 0xf, 0xffffffff);
186 enable_percpu_irq(clk->irq, 0); 267 enable_percpu_irq(clk->irq, 0);
187} 268}