From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peppe CAVALLARO Subject: [PATCH (sh-2.6) 1/4] clksource: Generic timer infrastructure Date: Tue, 22 Feb 2011 11:17:41 +0100 Message-ID: <1298369864-24429-2-git-send-email-peppe.cavallaro@st.com> References: <1298369864-24429-1-git-send-email-peppe.cavallaro@st.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Cc: Stuart MENEFY To: "linux-sh@vger.kernel.org" , "netdev@vger.kernel.org" Return-path: In-Reply-To: <1298369864-24429-1-git-send-email-peppe.cavallaro@st.com> Sender: linux-sh-owner@vger.kernel.org List-Id: netdev.vger.kernel.org From: Stuart Menefy Many devices targeted at the embedded market provide a number of generic timers which are capable of generating interrupts at a requested rate. These can then be used in the implementation of drivers for other peripherals which require a timer interrupt, without having to provide an additional timer as part of that peripheral. A code provides a simple abstraction layer which allows a timer to be registered, and for a driver to request a timer. Currently this doesn't provide any of the additional information, such as precision or position in clock framework which might be required for a fully featured driver. Signed-off-by: Stuart Menefy Hacked-by: Giuseppe Cavallaro --- drivers/clocksource/Makefile | 1 + drivers/clocksource/generictimer.c | 60 ++++++++++++++++++++++++++++++++++++ include/linux/generictimer.h | 41 ++++++++++++++++++++++++ 3 files changed, 102 insertions(+), 0 deletions(-) create mode 100644 drivers/clocksource/generictimer.c create mode 100644 include/linux/generictimer.h diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index be61ece..b0be293 100644 --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -6,3 +6,4 @@ obj-$(CONFIG_CS5535_CLOCK_EVENT_SRC) += cs5535-clockevt.o obj-$(CONFIG_SH_TIMER_CMT) += sh_cmt.o obj-$(CONFIG_SH_TIMER_MTU2) += sh_mtu2.o obj-$(CONFIG_SH_TIMER_TMU) += sh_tmu.o +obj-y += generictimer.o diff --git a/drivers/clocksource/generictimer.c b/drivers/clocksource/generictimer.c new file mode 100644 index 0000000..a74a87a --- /dev/null +++ b/drivers/clocksource/generictimer.c @@ -0,0 +1,60 @@ +/* + * Simple generic hardware timer interface + * + * Copyright (C) 2010 STMicroelectronics Limited + * Authors: Giuseppe Cavallaro + * Stuart Menefy + * + * May be copied or modified under the terms of the GNU General Public + * License. See linux/COPYING for more information. + */ + +#include +#include +#include +#include + +static DEFINE_MUTEX(gt_mutex); +static LIST_HEAD(gt_list); + +void generic_timer_register_device(struct generic_timer *gt) +{ + mutex_lock(>_mutex); + list_add(>->list, >_list); + mutex_unlock(>_mutex); +} + +struct generic_timer *generic_timer_claim(void (*handler) (void *), void *data) +{ + struct generic_timer *gt = NULL; + + if (!handler) { + pr_err("%s: invalid handler\n", __func__); + return NULL; + } + + mutex_lock(>_mutex); + if (!list_empty(>_list)) { + struct list_head *list = gt_list.next; + list_del(list); + gt = container_of(list, struct generic_timer, list); + } + mutex_unlock(>_mutex); + + if (!gt) + return NULL; + + /* Prepare the new handler */ + gt->priv_handler = handler; + gt->data = data; + + return gt; +} + +void generic_timer_release(struct generic_timer *gt) +{ + /* Just in case... */ + generic_timer_stop(gt); + + generic_timer_register_device(gt); +} diff --git a/include/linux/generictimer.h b/include/linux/generictimer.h new file mode 100644 index 0000000..87fb656 --- /dev/null +++ b/include/linux/generictimer.h @@ -0,0 +1,41 @@ +#ifndef __STM_GENERIC_TIMER_H +#define __STM_GENERIC_TIMER_H + +#include + +/* Generic timer device intrface */ + +struct generic_timer { + char *name; + struct list_head list; + void (*priv_handler)(void *data); + void *data; + void (*timer_start)(struct generic_timer *gt); + void (*timer_stop)(struct generic_timer *gt); + void (*set_rate)(struct generic_timer *gt, unsigned long rate); +}; + +void generic_timer_register_device(struct generic_timer *gt); + +/* Driver interface */ + +struct generic_timer *generic_timer_claim(void (*handler)(void *), void *data); +void generic_timer_release(struct generic_timer *gt); + +static inline void generic_timer_start(struct generic_timer *gt) +{ + gt->timer_start(gt); +} + +static inline void generic_timer_stop(struct generic_timer *gt) +{ + gt->timer_stop(gt); +} + +static inline void generic_timer_set_rate(struct generic_timer *gt, + unsigned long rate) +{ + gt->set_rate(gt, rate); +} + +#endif /* __STM_GENERIC_TIMER_H */ -- 1.7.4