From: vaibhav.hiremath@linaro.org (Vaibhav Hiremath) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH-RESEND 1/3] i2c: core: append hardware lock with bus lock Date: Wed, 3 Jun 2015 00:15:29 +0530 [thread overview] Message-ID: <1433270731-23790-2-git-send-email-vaibhav.hiremath@linaro.org> (raw) In-Reply-To: <1433270731-23790-1-git-send-email-vaibhav.hiremath@linaro.org> To justify the need for hardware lock, lets take a real usecase scenario - In case of Marvell SoC, PXA910 silicon, both AP and CP are present and these two ARM cores are sharing one pair of I2C pins. In order to keep I2C transaction operated with atomic, hardware lock (RIPC) is required. This patch extends support for atomic operation by adding hardware lock. History: The attempt has been made to push this patch-sets upstream sometime back in 2011, but not sure what happened later. I am making another attempt, hopefully will conclude it now. Link to previous patch: http://marc.info/?l=linux-i2c&m=130432846300735&w=2 Signed-off-by: Haojian Zhuang <haojian.zhuang@marvell.com> Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org> --- drivers/i2c/i2c-core.c | 22 ++++++++++++++++++---- include/linux/i2c.h | 5 +++++ 2 files changed, 23 insertions(+), 4 deletions(-) diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 987c124..daea523 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -868,8 +868,11 @@ void i2c_lock_adapter(struct i2c_adapter *adapter) if (parent) i2c_lock_adapter(parent); - else + else { rt_mutex_lock(&adapter->bus_lock); + if (adapter->hardware_lock) + adapter->hardware_lock(adapter); + } } EXPORT_SYMBOL_GPL(i2c_lock_adapter); @@ -880,11 +883,19 @@ EXPORT_SYMBOL_GPL(i2c_lock_adapter); static int i2c_trylock_adapter(struct i2c_adapter *adapter) { struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); + int ret = 0; if (parent) return i2c_trylock_adapter(parent); - else - return rt_mutex_trylock(&adapter->bus_lock); + else { + ret = rt_mutex_trylock(&adapter->bus_lock); + if (ret && adapter->hardware_trylock) { + ret = adapter->hardware_trylock(adapter); + if (!ret) + i2c_unlock_adapter(adapter); + } + return ret; + } } /** @@ -897,8 +908,11 @@ void i2c_unlock_adapter(struct i2c_adapter *adapter) if (parent) i2c_unlock_adapter(parent); - else + else { + if (adapter->hardware_unlock) + adapter->hardware_unlock(adapter); rt_mutex_unlock(&adapter->bus_lock); + } } EXPORT_SYMBOL_GPL(i2c_unlock_adapter); diff --git a/include/linux/i2c.h b/include/linux/i2c.h index e83a738..0758fb3 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -504,6 +504,11 @@ struct i2c_adapter { /* data fields that are valid for all devices */ struct rt_mutex bus_lock; + /* if hardware lock feature provided */ + void (*hardware_lock)(struct i2c_adapter *); + void (*hardware_unlock)(struct i2c_adapter *); + int (*hardware_trylock)(struct i2c_adapter *); + int timeout; /* in jiffies */ int retries; struct device dev; /* the adapter device */ -- 1.9.1
WARNING: multiple messages have this Message-ID (diff)
From: Vaibhav Hiremath <vaibhav.hiremath-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> To: linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Cc: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, wsa-z923LK4zBo2bacvFa/9K2g@public.gmane.org, Vaibhav Hiremath <vaibhav.hiremath-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>, Haojian Zhuang <haojian.zhuang-eYqpPyKDWXRBDgjK7y7TUQ@public.gmane.org> Subject: [PATCH-RESEND 1/3] i2c: core: append hardware lock with bus lock Date: Wed, 3 Jun 2015 00:15:29 +0530 [thread overview] Message-ID: <1433270731-23790-2-git-send-email-vaibhav.hiremath@linaro.org> (raw) In-Reply-To: <1433270731-23790-1-git-send-email-vaibhav.hiremath-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> To justify the need for hardware lock, lets take a real usecase scenario - In case of Marvell SoC, PXA910 silicon, both AP and CP are present and these two ARM cores are sharing one pair of I2C pins. In order to keep I2C transaction operated with atomic, hardware lock (RIPC) is required. This patch extends support for atomic operation by adding hardware lock. History: The attempt has been made to push this patch-sets upstream sometime back in 2011, but not sure what happened later. I am making another attempt, hopefully will conclude it now. Link to previous patch: http://marc.info/?l=linux-i2c&m=130432846300735&w=2 Signed-off-by: Haojian Zhuang <haojian.zhuang-eYqpPyKDWXRBDgjK7y7TUQ@public.gmane.org> Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> --- drivers/i2c/i2c-core.c | 22 ++++++++++++++++++---- include/linux/i2c.h | 5 +++++ 2 files changed, 23 insertions(+), 4 deletions(-) diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 987c124..daea523 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -868,8 +868,11 @@ void i2c_lock_adapter(struct i2c_adapter *adapter) if (parent) i2c_lock_adapter(parent); - else + else { rt_mutex_lock(&adapter->bus_lock); + if (adapter->hardware_lock) + adapter->hardware_lock(adapter); + } } EXPORT_SYMBOL_GPL(i2c_lock_adapter); @@ -880,11 +883,19 @@ EXPORT_SYMBOL_GPL(i2c_lock_adapter); static int i2c_trylock_adapter(struct i2c_adapter *adapter) { struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); + int ret = 0; if (parent) return i2c_trylock_adapter(parent); - else - return rt_mutex_trylock(&adapter->bus_lock); + else { + ret = rt_mutex_trylock(&adapter->bus_lock); + if (ret && adapter->hardware_trylock) { + ret = adapter->hardware_trylock(adapter); + if (!ret) + i2c_unlock_adapter(adapter); + } + return ret; + } } /** @@ -897,8 +908,11 @@ void i2c_unlock_adapter(struct i2c_adapter *adapter) if (parent) i2c_unlock_adapter(parent); - else + else { + if (adapter->hardware_unlock) + adapter->hardware_unlock(adapter); rt_mutex_unlock(&adapter->bus_lock); + } } EXPORT_SYMBOL_GPL(i2c_unlock_adapter); diff --git a/include/linux/i2c.h b/include/linux/i2c.h index e83a738..0758fb3 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -504,6 +504,11 @@ struct i2c_adapter { /* data fields that are valid for all devices */ struct rt_mutex bus_lock; + /* if hardware lock feature provided */ + void (*hardware_lock)(struct i2c_adapter *); + void (*hardware_unlock)(struct i2c_adapter *); + int (*hardware_trylock)(struct i2c_adapter *); + int timeout; /* in jiffies */ int retries; struct device dev; /* the adapter device */ -- 1.9.1
next prev parent reply other threads:[~2015-06-02 18:45 UTC|newest] Thread overview: 125+ messages / expand[flat|nested] mbox.gz Atom feed top [not found] <vaibhav.hiremath@linaro.org> 2015-06-02 18:45 ` [PATCH-RESEND 0/3] i2c: core/pxa: Add support for hardware lock Vaibhav Hiremath 2015-06-02 18:45 ` Vaibhav Hiremath 2015-06-02 18:45 ` Vaibhav Hiremath [this message] 2015-06-02 18:45 ` [PATCH-RESEND 1/3] i2c: core: append hardware lock with bus lock Vaibhav Hiremath 2015-06-02 18:45 ` [PATCH-RESEND 2/3] i2c: pxa: Add support for hardware lock Vaibhav Hiremath 2015-06-02 18:45 ` Vaibhav Hiremath 2015-06-02 18:45 ` [PATCH-RESEND 3/3] i2c: pxa: Add pin ctrl support for CP core access Vaibhav Hiremath 2015-06-02 18:45 ` Vaibhav Hiremath 2015-06-16 8:28 ` [PATCH-RESEND 0/3] i2c: core/pxa: Add support for hardware lock Vaibhav Hiremath 2015-06-16 8:28 ` Vaibhav Hiremath 2015-07-07 6:43 ` Vaibhav Hiremath 2015-07-07 6:43 ` Vaibhav Hiremath 2015-10-25 9:52 ` Wolfram Sang 2015-10-25 9:52 ` Wolfram Sang 2015-06-15 15:49 ` [PATCH-V2 00/12] i2c: pxa: Fixes, cleanup and support for pxa910 family Vaibhav Hiremath 2015-06-15 15:49 ` Vaibhav Hiremath 2015-06-15 15:49 ` [PATCH-V2 01/12] i2c: pxa: keep i2c irq ON in suspend Vaibhav Hiremath 2015-06-15 15:49 ` Vaibhav Hiremath 2015-06-15 15:49 ` [PATCH-V2 02/12] i2c: pxa: No need to set slave addr for i2c master mode reset Vaibhav Hiremath 2015-06-15 15:49 ` Vaibhav Hiremath 2015-07-03 20:58 ` Robert Jarzmik 2015-07-03 20:58 ` Robert Jarzmik 2015-06-15 15:49 ` [PATCH-V2 03/12] i2c: pxa: Return I2C_RETRY when timeout in pio mode Vaibhav Hiremath 2015-06-15 15:49 ` Vaibhav Hiremath 2015-06-16 5:31 ` Shubhrajyoti Datta 2015-06-16 5:31 ` Shubhrajyoti Datta 2015-06-16 7:41 ` Vaibhav Hiremath 2015-06-16 7:41 ` Vaibhav Hiremath 2015-07-03 21:07 ` Robert Jarzmik 2015-07-03 21:07 ` Robert Jarzmik 2015-06-15 15:49 ` [PATCH-V2 04/12] i2c: pxa: Reset i2c controller on timeout in interrupt and " Vaibhav Hiremath 2015-06-15 15:49 ` Vaibhav Hiremath 2015-07-03 15:27 ` Robert Jarzmik 2015-07-03 15:27 ` Robert Jarzmik 2015-07-03 18:13 ` Vaibhav Hiremath 2015-07-03 18:13 ` Vaibhav Hiremath 2015-06-15 15:49 ` [PATCH-V2 05/12] i2c: pxa: Remove compile warnning in 64bit mode Vaibhav Hiremath 2015-06-15 15:49 ` Vaibhav Hiremath 2015-06-15 15:49 ` [PATCH-V2 06/12] i2c: pxa: Update debug function to dump more info on error Vaibhav Hiremath 2015-06-15 15:49 ` Vaibhav Hiremath 2015-06-15 15:49 ` [PATCH-V2 07/12] i2c:pxa: Use devm_ variants in probe function Vaibhav Hiremath 2015-06-15 15:49 ` Vaibhav Hiremath 2015-07-03 15:28 ` Robert Jarzmik 2015-07-03 15:28 ` Robert Jarzmik 2015-07-03 18:14 ` Vaibhav Hiremath 2015-07-03 18:14 ` Vaibhav Hiremath 2015-06-15 15:49 ` [PATCH-V2 08/12] i2c: pxa: enable/disable i2c module across msg xfer Vaibhav Hiremath 2015-06-15 15:49 ` Vaibhav Hiremath 2015-07-03 15:28 ` Robert Jarzmik 2015-07-03 15:28 ` Robert Jarzmik 2015-07-03 18:23 ` Vaibhav Hiremath 2015-07-03 18:23 ` Vaibhav Hiremath 2015-07-03 18:48 ` Vaibhav Hiremath 2015-07-03 18:48 ` Vaibhav Hiremath 2015-07-03 19:44 ` Robert Jarzmik 2015-07-03 19:44 ` Robert Jarzmik 2015-06-15 15:49 ` [PATCH-V2 09/12] Documentation: binding: add new property 'disable_after_xfer' to i2c-pxa Vaibhav Hiremath 2015-06-15 15:49 ` Vaibhav Hiremath 2015-06-15 15:49 ` [PATCH-V2 10/12] i2c: pxa: Add support for pxa910/988 & new configuration features Vaibhav Hiremath 2015-06-15 15:49 ` Vaibhav Hiremath 2015-06-15 15:49 ` [PATCH-V2 11/12] i2c: pxa: Add ILCR (tLow & tHigh) configuration support Vaibhav Hiremath 2015-06-15 15:49 ` Vaibhav Hiremath 2015-07-03 15:28 ` Robert Jarzmik 2015-07-03 15:28 ` Robert Jarzmik 2015-07-03 18:17 ` Vaibhav Hiremath 2015-07-03 18:17 ` Vaibhav Hiremath 2015-06-15 15:49 ` [PATCH-V2 12/12] Documentation: binding: add sclk adjustment properties to i2c-pxa Vaibhav Hiremath 2015-06-15 15:49 ` Vaibhav Hiremath 2015-06-16 13:22 ` Rob Herring 2015-06-16 13:22 ` Rob Herring 2015-06-16 14:25 ` Vaibhav Hiremath 2015-06-16 14:25 ` Vaibhav Hiremath 2015-06-29 8:52 ` [PATCH-V2 00/12] i2c: pxa: Fixes, cleanup and support for pxa910 family Vaibhav Hiremath 2015-06-29 8:52 ` Vaibhav Hiremath 2015-07-02 16:54 ` Vaibhav Hiremath 2015-07-02 16:54 ` Vaibhav Hiremath 2015-06-17 18:58 [PATCH-v2 0/3] mfd: 88pm800: Add Device tree support Vaibhav Hiremath 2015-06-17 18:58 ` Vaibhav Hiremath 2015-06-17 18:58 ` [rtc-linux] " Vaibhav Hiremath 2015-06-17 18:58 ` [PATCH-v2 1/3] mfd: 88pm800: Add device " Vaibhav Hiremath 2015-06-17 18:58 ` Vaibhav Hiremath 2015-06-17 18:58 ` [rtc-linux] " Vaibhav Hiremath 2015-06-17 18:58 ` Vaibhav Hiremath 2015-06-17 18:58 ` [PATCH-v2] rtc: 88pm80x: add " Vaibhav Hiremath 2015-06-17 18:58 ` Vaibhav Hiremath 2015-06-17 18:58 ` [rtc-linux] " Vaibhav Hiremath 2015-06-20 0:43 ` Alexandre Belloni 2015-06-20 0:43 ` Alexandre Belloni 2015-06-20 0:43 ` Alexandre Belloni 2015-06-20 0:43 ` Alexandre Belloni 2015-06-25 7:46 ` Vaibhav Hiremath 2015-06-25 7:46 ` Vaibhav Hiremath 2015-06-25 7:46 ` Vaibhav Hiremath 2015-06-25 7:46 ` Vaibhav Hiremath 2015-07-07 6:37 ` Vaibhav Hiremath 2015-07-07 6:37 ` Vaibhav Hiremath 2015-07-07 6:37 ` Vaibhav Hiremath 2015-07-07 6:37 ` Vaibhav Hiremath 2015-06-17 18:58 ` [PATCH-v2 2/3] mfd: 88pm800: Allow configuration of interrupt clear method Vaibhav Hiremath 2015-06-17 18:58 ` Vaibhav Hiremath 2015-06-17 18:58 ` [rtc-linux] " Vaibhav Hiremath 2015-06-17 18:58 ` Vaibhav Hiremath 2015-06-17 18:58 ` [PATCH-v2 3/3] mfd: devicetree: bindings: Add new 88pm800 mfd binding Vaibhav Hiremath 2015-06-17 18:58 ` Vaibhav Hiremath 2015-06-17 18:58 ` [rtc-linux] " Vaibhav Hiremath 2015-06-17 18:58 ` Vaibhav Hiremath 2015-06-23 15:37 ` Rob Herring 2015-06-23 15:37 ` Rob Herring 2015-06-23 15:37 ` [rtc-linux] " Rob Herring 2015-06-23 15:37 ` Rob Herring 2015-06-23 17:02 ` Vaibhav Hiremath 2015-06-23 17:02 ` Vaibhav Hiremath 2015-06-23 17:02 ` [rtc-linux] " Vaibhav Hiremath 2015-06-24 0:29 ` Krzysztof Kozlowski 2015-06-24 0:29 ` Krzysztof Kozlowski 2015-06-24 0:29 ` [rtc-linux] " Krzysztof Kozlowski 2015-06-24 0:29 ` Krzysztof Kozlowski 2015-06-24 5:19 ` Vaibhav Hiremath 2015-06-24 5:19 ` Vaibhav Hiremath 2015-06-24 5:19 ` [rtc-linux] " Vaibhav Hiremath 2015-06-24 5:19 ` Vaibhav Hiremath 2015-06-23 5:07 ` [PATCH-v2 0/3] mfd: 88pm800: Add Device tree support Vaibhav Hiremath 2015-06-23 5:07 ` Vaibhav Hiremath 2015-06-23 5:07 ` [rtc-linux] " Vaibhav Hiremath 2015-06-23 5:07 ` Vaibhav Hiremath
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