hwspinlock: sprd: Add hardware spinlock driver

Message ID f951b1c5aca85b4f1aa23fbf8a24ed315439bb58.1494914340.git.baolin.wang@spreadtrum.com
State New
Headers show

Commit Message

Baolin Wang May 16, 2017, 7:54 a.m.
The Spreadtrum hardware spinlock device can provide hardware assistance
for synchronization between the multiple subsystems.

Signed-off-by: Baolin Wang <baolin.wang@spreadtrum.com>

---
 drivers/hwspinlock/Kconfig           |    9 ++
 drivers/hwspinlock/Makefile          |    1 +
 drivers/hwspinlock/sprd_hwspinlock.c |  243 ++++++++++++++++++++++++++++++++++
 3 files changed, 253 insertions(+)
 create mode 100644 drivers/hwspinlock/sprd_hwspinlock.c

-- 
1.7.9.5

Comments

Bjorn Andersson May 16, 2017, 7:18 p.m. | #1
On Tue 16 May 00:54 PDT 2017, Baolin Wang wrote:

> diff --git a/drivers/hwspinlock/Makefile b/drivers/hwspinlock/Makefile

> index 6b59cb5a..03c442f 100644

> --- a/drivers/hwspinlock/Makefile

> +++ b/drivers/hwspinlock/Makefile

> @@ -7,3 +7,4 @@ obj-$(CONFIG_HWSPINLOCK_OMAP)		+= omap_hwspinlock.o

>  obj-$(CONFIG_HWSPINLOCK_QCOM)		+= qcom_hwspinlock.o

>  obj-$(CONFIG_HWSPINLOCK_SIRF)		+= sirf_hwspinlock.o

>  obj-$(CONFIG_HSEM_U8500)		+= u8500_hsem.o

> +obj-$(CONFIG_HWSPINLOCK_SPRD)		+= sprd_hwspinlock.o


Please move this one line up, to keep the alphabetical sort order
(please make sure to update the order in Kconfig accordingly).

> diff --git a/drivers/hwspinlock/sprd_hwspinlock.c b/drivers/hwspinlock/sprd_hwspinlock.c

> new file mode 100644

> index 0000000..898738f

> --- /dev/null

> +++ b/drivers/hwspinlock/sprd_hwspinlock.c

> @@ -0,0 +1,243 @@

> +/*

> + * Spreadtrum hardware spinlock driver

> + * Copyright (C) 2017 Spreadtrum  - http://www.spreadtrum.com

> + *

> + * This program is free software; you can redistribute it and/or

> + * modify it under the terms of the GNU General Public License

> + * version 2 as published by the Free Software Foundation.

> + *

> + * This program is distributed in the hope that it will be useful, but

> + * WITHOUT ANY WARRANTY; without even the implied warranty of

> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

> + * General Public License for more details.

> + */

> +

> +#include <linux/bitops.h>

> +#include <linux/clk.h>

> +#include <linux/delay.h>

> +#include <linux/device.h>

> +#include <linux/hwspinlock.h>

> +#include <linux/io.h>

> +#include <linux/kernel.h>

> +#include <linux/module.h>

> +#include <linux/of.h>

> +#include <linux/of_device.h>

> +#include <linux/platform_device.h>

> +#include <linux/pm_runtime.h>

> +#include <linux/slab.h>

> +#include <linux/spinlock.h>


I don't see a need for spinlock.h

> +

> +#include "hwspinlock_internal.h"

> +

> +/* hwspinlock registers definition */

> +#define HWSPINLOCK_RECCTRL		0x4

> +#define HWSPINLOCK_TTLSTS		0x8

> +#define HWSPINLOCK_FLAG0		0x10

> +#define HWSPINLOCK_FLAG1		0x14

> +#define HWSPINLOCK_FLAG2		0x18

> +#define HWSPINLOCK_FLAG3		0x1c


These flags are unused.

> +#define HWSPINLOCK_MASTERID(_X_)	(0x80 + 0x4 * (_X_))

> +#define HWSPINLOCK_TOKEN(_X_)		(0x800 + 0x4 * (_X_))

> +#define HWSPINLOCK_VERID		0xFFC


verid is unused.

> +

> +/* untoken lock value */


untaken? Perhaps "unlocked value" instead?

> +#define HWSPINLOCK_NOTTAKEN		0x55aa10c5

> +/* bits definition of RECCTRL reg */

> +#define HWSPINLOCK_ID			0x0


id is unused.

> +#define HWSPINLOCK_USER_BITS		0x1

> +

> +/* hwspinlock number */

> +#define SPRD_HWLOCKS_NUM		32

> +

> +struct sprd_hwspinlock_dev {

> +	void __iomem *base;

> +	struct clk *clk;

> +	unsigned char status[SPRD_HWLOCKS_NUM];

> +	struct hwspinlock_device bank;

> +};

> +

> +static const struct of_device_id sprd_hwspinlock_of_match[] = {

> +	{ .compatible = "sprd,hwspinlock-r3p0",},

> +	{ /* sentinel */ }

> +};


Please move this next to the definition of sprd_hwspinlock_driver and
add the missing MODULE_DEVICE_TABLE(of, sprd_hwspinlock_of_match);

> +

> +static struct sprd_hwspinlock_dev *sprd_lock_to_dev(struct hwspinlock *lock)

> +{

> +	struct hwspinlock_device *hwbank;

> +	unsigned int lock_id = hwlock_to_id(lock);

> +

> +	hwbank = container_of(lock, struct hwspinlock_device, lock[lock_id]);

> +	return container_of(hwbank, struct sprd_hwspinlock_dev, bank);


As you platform_set_drvdata the sprd_hwspinlock_dev in probe you can
implement this with function with

return dev_get_drvdata(lock->bank->dev);

> +}

> +

> +/* set the hardware spinlock record type */

> +static void sprd_set_hwspinlock_record(struct sprd_hwspinlock_dev *sprd_hwlock,

> +				       unsigned int type)

> +{

> +	writel_relaxed(type, sprd_hwlock->base + HWSPINLOCK_RECCTRL);


Please use writel() and please inline this write into the probe function.

> +}

> +

> +/* get the hardware spinlock master/user id */

> +static unsigned int sprd_get_hwspinlock_id(struct sprd_hwspinlock_dev *sprd_hwlock,

> +					   unsigned int lock_id)

> +{

> +	return readl_relaxed(sprd_hwlock->base + HWSPINLOCK_MASTERID(lock_id));


Please use readl() and please inline this function in
sprd_hwspinlock_trylock()

> +}

> +

> +/* record the hardware spinlock status */

> +static int sprd_record_hwspinlock_sts(struct hwspinlock *lock)


The hwlock->status is not read by anyone, so please remove this
function.

> +{

> +	struct sprd_hwspinlock_dev *sprd_hwlock = sprd_lock_to_dev(lock);

> +	unsigned int lock_id = hwlock_to_id(lock);

> +	unsigned char status;

> +

> +	if (lock_id >= SPRD_HWLOCKS_NUM) {

> +		dev_err(sprd_hwlock->bank.dev, "lock id is out of the range\n");

> +		return -ENXIO;

> +	}

> +

> +	/* get the hardware spinlock status */

> +	status = !!(readl_relaxed(sprd_hwlock->base + HWSPINLOCK_TTLSTS) &

> +		    BIT(lock_id));

> +

> +	sprd_hwlock->status[lock_id] = status;

> +	return 0;

> +}

> +

> +/* try to lock the hardware spinlock */

> +static int sprd_hwspinlock_trylock(struct hwspinlock *lock)

> +{

> +	struct sprd_hwspinlock_dev *sprd_hwlock = sprd_lock_to_dev(lock);

> +	void __iomem *addr = lock->priv;

> +

> +	if (!readl_relaxed(addr))

> +		goto locked;


Please use readl() and as sprd_record_hwspinlock_sts() doesn't seem to
be needed, return 1 here.

> +

> +	dev_warn(sprd_hwlock->bank.dev,

> +		 "hwspinlock [%d] lock failed and master/user id = %d!\n",

> +		 hwlock_to_id(lock),

> +		 sprd_get_hwspinlock_id(sprd_hwlock, hwlock_to_id(lock)));


Please use local variables, rather than calling these functions in the
parameter list.

> +	return 0;

> +

> +locked:

> +	sprd_record_hwspinlock_sts(lock);

> +	return 1;

> +}

> +

> +/* unlock the hardware spinlock */

> +static void sprd_hwspinlock_unlock(struct hwspinlock *lock)

> +{

> +	void __iomem *lock_addr = lock->priv;

> +

> +	writel_relaxed(HWSPINLOCK_NOTTAKEN, lock_addr);


Please use writel()

> +	sprd_record_hwspinlock_sts(lock);

> +}

> +

> +/* The specs recommended below number as the retry delay time */

> +static void sprd_hwspinlock_relax(struct hwspinlock *lock)

> +{

> +	ndelay(10);

> +}

> +

> +static const struct hwspinlock_ops sprd_hwspinlock_ops = {

> +	.trylock = sprd_hwspinlock_trylock,

> +	.unlock = sprd_hwspinlock_unlock,

> +	.relax = sprd_hwspinlock_relax,

> +};

> +

> +static int sprd_hwspinlock_probe(struct platform_device *pdev)

> +{

> +	struct sprd_hwspinlock_dev *sprd_hwlock;

> +	struct hwspinlock *lock;

> +	struct resource *res;

> +	int i, ret;

> +

> +	if (!pdev->dev.of_node)

> +		return -ENODEV;

> +

> +	sprd_hwlock = devm_kzalloc(&pdev->dev,

> +				   sizeof(struct sprd_hwspinlock_dev) +

> +				   SPRD_HWLOCKS_NUM * sizeof(*lock),

> +				   GFP_KERNEL);

> +	if (!sprd_hwlock)

> +		return -ENOMEM;

> +

> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

> +	sprd_hwlock->base = devm_ioremap_resource(&pdev->dev, res);

> +	if (IS_ERR(sprd_hwlock->base))

> +		return PTR_ERR(sprd_hwlock->base);

> +

> +	sprd_hwlock->clk = of_clk_get_by_name(pdev->dev.of_node, "enable");


Please use devm_clk_get(&pdev->dev, "enable");

> +	if (IS_ERR(sprd_hwlock->clk)) {

> +		dev_err(&pdev->dev, "get hwspinlock clock failed!\n");

> +		return PTR_ERR(sprd_hwlock->clk);

> +	}

> +

> +	clk_prepare_enable(sprd_hwlock->clk);

> +

> +	/* set the hwspinlock to record user id to identify subsystems */

> +	sprd_set_hwspinlock_record(sprd_hwlock, HWSPINLOCK_USER_BITS);

> +

> +	for (i = 0; i < SPRD_HWLOCKS_NUM; i++) {

> +		lock = &sprd_hwlock->bank.lock[i];

> +		lock->priv = sprd_hwlock->base + HWSPINLOCK_TOKEN(i);

> +	}

> +

> +	platform_set_drvdata(pdev, sprd_hwlock);

> +	pm_runtime_enable(&pdev->dev);

> +

> +	ret = hwspin_lock_register(&sprd_hwlock->bank, &pdev->dev,

> +				   &sprd_hwspinlock_ops, 0, SPRD_HWLOCKS_NUM);

> +	if (ret) {

> +		dev_err(&pdev->dev, "hwspinlock register failed!\n");


All error paths of hwspin_lock_register() will cause a log print already.

> +		pm_runtime_disable(&pdev->dev);

> +		clk_disable_unprepare(sprd_hwlock->clk);

> +		return ret;

> +	}

> +

> +	return 0;

> +}

> +

> +static int sprd_hwspinlock_remove(struct platform_device *pdev)

> +{

> +	struct sprd_hwspinlock_dev *sprd_hwlock = platform_get_drvdata(pdev);

> +	int ret;

> +

> +	ret = hwspin_lock_unregister(&sprd_hwlock->bank);

> +	if (ret) {

> +		dev_err(&pdev->dev, "hwspinlock unregister failed: %d\n", ret);


All errors in hwspin_lock_unregister() will cause log prints.

> +		return ret;


You don't want to return early from a platform_driver remove function,
the caller ignores this and you will just leak resources.

> +	}

> +

> +	pm_runtime_disable(&pdev->dev);

> +	clk_disable_unprepare(sprd_hwlock->clk);

> +	return 0;

> +}

> +

> +static struct platform_driver sprd_hwspinlock_driver = {

> +	.probe = sprd_hwspinlock_probe,

> +	.remove = sprd_hwspinlock_remove,

> +	.driver = {

> +		.name = "sprd_hwspinlock",

> +		.owner = THIS_MODULE,


No need to set .owner in platform_drivers anymore.

> +		.of_match_table = of_match_ptr(sprd_hwspinlock_of_match),

> +	},

> +};

> +


Regards,
Bjorn
Baolin Wang May 17, 2017, 2:54 a.m. | #2
Hi Bjorn,

On 17 May 2017 at 03:18, Bjorn Andersson <bjorn.andersson@linaro.org> wrote:
> On Tue 16 May 00:54 PDT 2017, Baolin Wang wrote:

>

>> diff --git a/drivers/hwspinlock/Makefile b/drivers/hwspinlock/Makefile

>> index 6b59cb5a..03c442f 100644

>> --- a/drivers/hwspinlock/Makefile

>> +++ b/drivers/hwspinlock/Makefile

>> @@ -7,3 +7,4 @@ obj-$(CONFIG_HWSPINLOCK_OMAP)         += omap_hwspinlock.o

>>  obj-$(CONFIG_HWSPINLOCK_QCOM)                += qcom_hwspinlock.o

>>  obj-$(CONFIG_HWSPINLOCK_SIRF)                += sirf_hwspinlock.o

>>  obj-$(CONFIG_HSEM_U8500)             += u8500_hsem.o

>> +obj-$(CONFIG_HWSPINLOCK_SPRD)                += sprd_hwspinlock.o

>

> Please move this one line up, to keep the alphabetical sort order

> (please make sure to update the order in Kconfig accordingly).


OK.

>

>> diff --git a/drivers/hwspinlock/sprd_hwspinlock.c b/drivers/hwspinlock/sprd_hwspinlock.c

>> new file mode 100644

>> index 0000000..898738f

>> --- /dev/null

>> +++ b/drivers/hwspinlock/sprd_hwspinlock.c

>> @@ -0,0 +1,243 @@

>> +/*

>> + * Spreadtrum hardware spinlock driver

>> + * Copyright (C) 2017 Spreadtrum  - http://www.spreadtrum.com

>> + *

>> + * This program is free software; you can redistribute it and/or

>> + * modify it under the terms of the GNU General Public License

>> + * version 2 as published by the Free Software Foundation.

>> + *

>> + * This program is distributed in the hope that it will be useful, but

>> + * WITHOUT ANY WARRANTY; without even the implied warranty of

>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

>> + * General Public License for more details.

>> + */

>> +

>> +#include <linux/bitops.h>

>> +#include <linux/clk.h>

>> +#include <linux/delay.h>

>> +#include <linux/device.h>

>> +#include <linux/hwspinlock.h>

>> +#include <linux/io.h>

>> +#include <linux/kernel.h>

>> +#include <linux/module.h>

>> +#include <linux/of.h>

>> +#include <linux/of_device.h>

>> +#include <linux/platform_device.h>

>> +#include <linux/pm_runtime.h>

>> +#include <linux/slab.h>

>> +#include <linux/spinlock.h>

>

> I don't see a need for spinlock.h


Will remove it.

>

>> +

>> +#include "hwspinlock_internal.h"

>> +

>> +/* hwspinlock registers definition */

>> +#define HWSPINLOCK_RECCTRL           0x4

>> +#define HWSPINLOCK_TTLSTS            0x8

>> +#define HWSPINLOCK_FLAG0             0x10

>> +#define HWSPINLOCK_FLAG1             0x14

>> +#define HWSPINLOCK_FLAG2             0x18

>> +#define HWSPINLOCK_FLAG3             0x1c

>

> These flags are unused.


These may be used in future, but I will remove them now.

>

>> +#define HWSPINLOCK_MASTERID(_X_)     (0x80 + 0x4 * (_X_))

>> +#define HWSPINLOCK_TOKEN(_X_)                (0x800 + 0x4 * (_X_))

>> +#define HWSPINLOCK_VERID             0xFFC

>

> verid is unused.


Will remove it.

>

>> +

>> +/* untoken lock value */

>

> untaken? Perhaps "unlocked value" instead?


OK.

>

>> +#define HWSPINLOCK_NOTTAKEN          0x55aa10c5

>> +/* bits definition of RECCTRL reg */

>> +#define HWSPINLOCK_ID                        0x0

>

> id is unused.


Will remove it now.

>

>> +#define HWSPINLOCK_USER_BITS         0x1

>> +

>> +/* hwspinlock number */

>> +#define SPRD_HWLOCKS_NUM             32

>> +

>> +struct sprd_hwspinlock_dev {

>> +     void __iomem *base;

>> +     struct clk *clk;

>> +     unsigned char status[SPRD_HWLOCKS_NUM];

>> +     struct hwspinlock_device bank;

>> +};

>> +

>> +static const struct of_device_id sprd_hwspinlock_of_match[] = {

>> +     { .compatible = "sprd,hwspinlock-r3p0",},

>> +     { /* sentinel */ }

>> +};

>

> Please move this next to the definition of sprd_hwspinlock_driver and

> add the missing MODULE_DEVICE_TABLE(of, sprd_hwspinlock_of_match);


OK.

>

>> +

>> +static struct sprd_hwspinlock_dev *sprd_lock_to_dev(struct hwspinlock *lock)

>> +{

>> +     struct hwspinlock_device *hwbank;

>> +     unsigned int lock_id = hwlock_to_id(lock);

>> +

>> +     hwbank = container_of(lock, struct hwspinlock_device, lock[lock_id]);

>> +     return container_of(hwbank, struct sprd_hwspinlock_dev, bank);

>

> As you platform_set_drvdata the sprd_hwspinlock_dev in probe you can

> implement this with function with

>

> return dev_get_drvdata(lock->bank->dev);


Yes, you are correct, and I will change it.

>

>> +}

>> +

>> +/* set the hardware spinlock record type */

>> +static void sprd_set_hwspinlock_record(struct sprd_hwspinlock_dev *sprd_hwlock,

>> +                                    unsigned int type)

>> +{

>> +     writel_relaxed(type, sprd_hwlock->base + HWSPINLOCK_RECCTRL);

>

> Please use writel() and please inline this write into the probe function.


OK.

>

>> +}

>> +

>> +/* get the hardware spinlock master/user id */

>> +static unsigned int sprd_get_hwspinlock_id(struct sprd_hwspinlock_dev *sprd_hwlock,

>> +                                        unsigned int lock_id)

>> +{

>> +     return readl_relaxed(sprd_hwlock->base + HWSPINLOCK_MASTERID(lock_id));

>

> Please use readl() and please inline this function in

> sprd_hwspinlock_trylock()


OK.

>

>> +}

>> +

>> +/* record the hardware spinlock status */

>> +static int sprd_record_hwspinlock_sts(struct hwspinlock *lock)

>

> The hwlock->status is not read by anyone, so please remove this

> function.


Sometime we will dump memory to analyze the status of hardware
spinlocks, but if you still complain that I will remove it.

>

>> +{

>> +     struct sprd_hwspinlock_dev *sprd_hwlock = sprd_lock_to_dev(lock);

>> +     unsigned int lock_id = hwlock_to_id(lock);

>> +     unsigned char status;

>> +

>> +     if (lock_id >= SPRD_HWLOCKS_NUM) {

>> +             dev_err(sprd_hwlock->bank.dev, "lock id is out of the range\n");

>> +             return -ENXIO;

>> +     }

>> +

>> +     /* get the hardware spinlock status */

>> +     status = !!(readl_relaxed(sprd_hwlock->base + HWSPINLOCK_TTLSTS) &

>> +                 BIT(lock_id));

>> +

>> +     sprd_hwlock->status[lock_id] = status;

>> +     return 0;

>> +}

>> +

>> +/* try to lock the hardware spinlock */

>> +static int sprd_hwspinlock_trylock(struct hwspinlock *lock)

>> +{

>> +     struct sprd_hwspinlock_dev *sprd_hwlock = sprd_lock_to_dev(lock);

>> +     void __iomem *addr = lock->priv;

>> +

>> +     if (!readl_relaxed(addr))

>> +             goto locked;

>

> Please use readl() and as sprd_record_hwspinlock_sts() doesn't seem to

> be needed, return 1 here.


OK.

>

>> +

>> +     dev_warn(sprd_hwlock->bank.dev,

>> +              "hwspinlock [%d] lock failed and master/user id = %d!\n",

>> +              hwlock_to_id(lock),

>> +              sprd_get_hwspinlock_id(sprd_hwlock, hwlock_to_id(lock)));

>

> Please use local variables, rather than calling these functions in the

> parameter list.


OK.

>

>> +     return 0;

>> +

>> +locked:

>> +     sprd_record_hwspinlock_sts(lock);

>> +     return 1;

>> +}

>> +

>> +/* unlock the hardware spinlock */

>> +static void sprd_hwspinlock_unlock(struct hwspinlock *lock)

>> +{

>> +     void __iomem *lock_addr = lock->priv;

>> +

>> +     writel_relaxed(HWSPINLOCK_NOTTAKEN, lock_addr);

>

> Please use writel()

>

>> +     sprd_record_hwspinlock_sts(lock);

>> +}

>> +

>> +/* The specs recommended below number as the retry delay time */

>> +static void sprd_hwspinlock_relax(struct hwspinlock *lock)

>> +{

>> +     ndelay(10);

>> +}

>> +

>> +static const struct hwspinlock_ops sprd_hwspinlock_ops = {

>> +     .trylock = sprd_hwspinlock_trylock,

>> +     .unlock = sprd_hwspinlock_unlock,

>> +     .relax = sprd_hwspinlock_relax,

>> +};

>> +

>> +static int sprd_hwspinlock_probe(struct platform_device *pdev)

>> +{

>> +     struct sprd_hwspinlock_dev *sprd_hwlock;

>> +     struct hwspinlock *lock;

>> +     struct resource *res;

>> +     int i, ret;

>> +

>> +     if (!pdev->dev.of_node)

>> +             return -ENODEV;

>> +

>> +     sprd_hwlock = devm_kzalloc(&pdev->dev,

>> +                                sizeof(struct sprd_hwspinlock_dev) +

>> +                                SPRD_HWLOCKS_NUM * sizeof(*lock),

>> +                                GFP_KERNEL);

>> +     if (!sprd_hwlock)

>> +             return -ENOMEM;

>> +

>> +     res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

>> +     sprd_hwlock->base = devm_ioremap_resource(&pdev->dev, res);

>> +     if (IS_ERR(sprd_hwlock->base))

>> +             return PTR_ERR(sprd_hwlock->base);

>> +

>> +     sprd_hwlock->clk = of_clk_get_by_name(pdev->dev.of_node, "enable");

>

> Please use devm_clk_get(&pdev->dev, "enable");


OK.

>

>> +     if (IS_ERR(sprd_hwlock->clk)) {

>> +             dev_err(&pdev->dev, "get hwspinlock clock failed!\n");

>> +             return PTR_ERR(sprd_hwlock->clk);

>> +     }

>> +

>> +     clk_prepare_enable(sprd_hwlock->clk);

>> +

>> +     /* set the hwspinlock to record user id to identify subsystems */

>> +     sprd_set_hwspinlock_record(sprd_hwlock, HWSPINLOCK_USER_BITS);

>> +

>> +     for (i = 0; i < SPRD_HWLOCKS_NUM; i++) {

>> +             lock = &sprd_hwlock->bank.lock[i];

>> +             lock->priv = sprd_hwlock->base + HWSPINLOCK_TOKEN(i);

>> +     }

>> +

>> +     platform_set_drvdata(pdev, sprd_hwlock);

>> +     pm_runtime_enable(&pdev->dev);

>> +

>> +     ret = hwspin_lock_register(&sprd_hwlock->bank, &pdev->dev,

>> +                                &sprd_hwspinlock_ops, 0, SPRD_HWLOCKS_NUM);

>> +     if (ret) {

>> +             dev_err(&pdev->dev, "hwspinlock register failed!\n");

>

> All error paths of hwspin_lock_register() will cause a log print already.


Will remove the error info.

>

>> +             pm_runtime_disable(&pdev->dev);

>> +             clk_disable_unprepare(sprd_hwlock->clk);

>> +             return ret;

>> +     }

>> +

>> +     return 0;

>> +}

>> +

>> +static int sprd_hwspinlock_remove(struct platform_device *pdev)

>> +{

>> +     struct sprd_hwspinlock_dev *sprd_hwlock = platform_get_drvdata(pdev);

>> +     int ret;

>> +

>> +     ret = hwspin_lock_unregister(&sprd_hwlock->bank);

>> +     if (ret) {

>> +             dev_err(&pdev->dev, "hwspinlock unregister failed: %d\n", ret);

>

> All errors in hwspin_lock_unregister() will cause log prints.


OK.

>

>> +             return ret;

>

> You don't want to return early from a platform_driver remove function,

> the caller ignores this and you will just leak resources.


Yes, will ignore the return value from hwspin_lock_unregister().

>

>> +     }

>> +

>> +     pm_runtime_disable(&pdev->dev);

>> +     clk_disable_unprepare(sprd_hwlock->clk);

>> +     return 0;

>> +}

>> +

>> +static struct platform_driver sprd_hwspinlock_driver = {

>> +     .probe = sprd_hwspinlock_probe,

>> +     .remove = sprd_hwspinlock_remove,

>> +     .driver = {

>> +             .name = "sprd_hwspinlock",

>> +             .owner = THIS_MODULE,

>

> No need to set .owner in platform_drivers anymore.


OK. Very appreciate for your comments. Thanks.

-- 
Baolin.wang
Best Regards

Patch hide | download patch | download mbox

diff --git a/drivers/hwspinlock/Kconfig b/drivers/hwspinlock/Kconfig
index 73a4016..25304e0 100644
--- a/drivers/hwspinlock/Kconfig
+++ b/drivers/hwspinlock/Kconfig
@@ -53,4 +53,13 @@  config HSEM_U8500
 
 	  If unsure, say N.
 
+config HWSPINLOCK_SPRD
+	tristate "SPRD Hardware Spinlock device"
+	depends on ARCH_SPRD
+	select HWSPINLOCK
+	help
+	  Say y here to support the SPRD Hardware Spinlock device.
+
+	  If unsure, say N.
+
 endmenu
diff --git a/drivers/hwspinlock/Makefile b/drivers/hwspinlock/Makefile
index 6b59cb5a..03c442f 100644
--- a/drivers/hwspinlock/Makefile
+++ b/drivers/hwspinlock/Makefile
@@ -7,3 +7,4 @@  obj-$(CONFIG_HWSPINLOCK_OMAP)		+= omap_hwspinlock.o
 obj-$(CONFIG_HWSPINLOCK_QCOM)		+= qcom_hwspinlock.o
 obj-$(CONFIG_HWSPINLOCK_SIRF)		+= sirf_hwspinlock.o
 obj-$(CONFIG_HSEM_U8500)		+= u8500_hsem.o
+obj-$(CONFIG_HWSPINLOCK_SPRD)		+= sprd_hwspinlock.o
diff --git a/drivers/hwspinlock/sprd_hwspinlock.c b/drivers/hwspinlock/sprd_hwspinlock.c
new file mode 100644
index 0000000..898738f
--- /dev/null
+++ b/drivers/hwspinlock/sprd_hwspinlock.c
@@ -0,0 +1,243 @@ 
+/*
+ * Spreadtrum hardware spinlock driver
+ * Copyright (C) 2017 Spreadtrum  - http://www.spreadtrum.com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ */
+
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/hwspinlock.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#include "hwspinlock_internal.h"
+
+/* hwspinlock registers definition */
+#define HWSPINLOCK_RECCTRL		0x4
+#define HWSPINLOCK_TTLSTS		0x8
+#define HWSPINLOCK_FLAG0		0x10
+#define HWSPINLOCK_FLAG1		0x14
+#define HWSPINLOCK_FLAG2		0x18
+#define HWSPINLOCK_FLAG3		0x1c
+#define HWSPINLOCK_MASTERID(_X_)	(0x80 + 0x4 * (_X_))
+#define HWSPINLOCK_TOKEN(_X_)		(0x800 + 0x4 * (_X_))
+#define HWSPINLOCK_VERID		0xFFC
+
+/* untoken lock value */
+#define HWSPINLOCK_NOTTAKEN		0x55aa10c5
+/* bits definition of RECCTRL reg */
+#define HWSPINLOCK_ID			0x0
+#define HWSPINLOCK_USER_BITS		0x1
+
+/* hwspinlock number */
+#define SPRD_HWLOCKS_NUM		32
+
+struct sprd_hwspinlock_dev {
+	void __iomem *base;
+	struct clk *clk;
+	unsigned char status[SPRD_HWLOCKS_NUM];
+	struct hwspinlock_device bank;
+};
+
+static const struct of_device_id sprd_hwspinlock_of_match[] = {
+	{ .compatible = "sprd,hwspinlock-r3p0",},
+	{ /* sentinel */ }
+};
+
+static struct sprd_hwspinlock_dev *sprd_lock_to_dev(struct hwspinlock *lock)
+{
+	struct hwspinlock_device *hwbank;
+	unsigned int lock_id = hwlock_to_id(lock);
+
+	hwbank = container_of(lock, struct hwspinlock_device, lock[lock_id]);
+	return container_of(hwbank, struct sprd_hwspinlock_dev, bank);
+}
+
+/* set the hardware spinlock record type */
+static void sprd_set_hwspinlock_record(struct sprd_hwspinlock_dev *sprd_hwlock,
+				       unsigned int type)
+{
+	writel_relaxed(type, sprd_hwlock->base + HWSPINLOCK_RECCTRL);
+}
+
+/* get the hardware spinlock master/user id */
+static unsigned int sprd_get_hwspinlock_id(struct sprd_hwspinlock_dev *sprd_hwlock,
+					   unsigned int lock_id)
+{
+	return readl_relaxed(sprd_hwlock->base + HWSPINLOCK_MASTERID(lock_id));
+}
+
+/* record the hardware spinlock status */
+static int sprd_record_hwspinlock_sts(struct hwspinlock *lock)
+{
+	struct sprd_hwspinlock_dev *sprd_hwlock = sprd_lock_to_dev(lock);
+	unsigned int lock_id = hwlock_to_id(lock);
+	unsigned char status;
+
+	if (lock_id >= SPRD_HWLOCKS_NUM) {
+		dev_err(sprd_hwlock->bank.dev, "lock id is out of the range\n");
+		return -ENXIO;
+	}
+
+	/* get the hardware spinlock status */
+	status = !!(readl_relaxed(sprd_hwlock->base + HWSPINLOCK_TTLSTS) &
+		    BIT(lock_id));
+
+	sprd_hwlock->status[lock_id] = status;
+	return 0;
+}
+
+/* try to lock the hardware spinlock */
+static int sprd_hwspinlock_trylock(struct hwspinlock *lock)
+{
+	struct sprd_hwspinlock_dev *sprd_hwlock = sprd_lock_to_dev(lock);
+	void __iomem *addr = lock->priv;
+
+	if (!readl_relaxed(addr))
+		goto locked;
+
+	dev_warn(sprd_hwlock->bank.dev,
+		 "hwspinlock [%d] lock failed and master/user id = %d!\n",
+		 hwlock_to_id(lock),
+		 sprd_get_hwspinlock_id(sprd_hwlock, hwlock_to_id(lock)));
+	return 0;
+
+locked:
+	sprd_record_hwspinlock_sts(lock);
+	return 1;
+}
+
+/* unlock the hardware spinlock */
+static void sprd_hwspinlock_unlock(struct hwspinlock *lock)
+{
+	void __iomem *lock_addr = lock->priv;
+
+	writel_relaxed(HWSPINLOCK_NOTTAKEN, lock_addr);
+	sprd_record_hwspinlock_sts(lock);
+}
+
+/* The specs recommended below number as the retry delay time */
+static void sprd_hwspinlock_relax(struct hwspinlock *lock)
+{
+	ndelay(10);
+}
+
+static const struct hwspinlock_ops sprd_hwspinlock_ops = {
+	.trylock = sprd_hwspinlock_trylock,
+	.unlock = sprd_hwspinlock_unlock,
+	.relax = sprd_hwspinlock_relax,
+};
+
+static int sprd_hwspinlock_probe(struct platform_device *pdev)
+{
+	struct sprd_hwspinlock_dev *sprd_hwlock;
+	struct hwspinlock *lock;
+	struct resource *res;
+	int i, ret;
+
+	if (!pdev->dev.of_node)
+		return -ENODEV;
+
+	sprd_hwlock = devm_kzalloc(&pdev->dev,
+				   sizeof(struct sprd_hwspinlock_dev) +
+				   SPRD_HWLOCKS_NUM * sizeof(*lock),
+				   GFP_KERNEL);
+	if (!sprd_hwlock)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	sprd_hwlock->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(sprd_hwlock->base))
+		return PTR_ERR(sprd_hwlock->base);
+
+	sprd_hwlock->clk = of_clk_get_by_name(pdev->dev.of_node, "enable");
+	if (IS_ERR(sprd_hwlock->clk)) {
+		dev_err(&pdev->dev, "get hwspinlock clock failed!\n");
+		return PTR_ERR(sprd_hwlock->clk);
+	}
+
+	clk_prepare_enable(sprd_hwlock->clk);
+
+	/* set the hwspinlock to record user id to identify subsystems */
+	sprd_set_hwspinlock_record(sprd_hwlock, HWSPINLOCK_USER_BITS);
+
+	for (i = 0; i < SPRD_HWLOCKS_NUM; i++) {
+		lock = &sprd_hwlock->bank.lock[i];
+		lock->priv = sprd_hwlock->base + HWSPINLOCK_TOKEN(i);
+	}
+
+	platform_set_drvdata(pdev, sprd_hwlock);
+	pm_runtime_enable(&pdev->dev);
+
+	ret = hwspin_lock_register(&sprd_hwlock->bank, &pdev->dev,
+				   &sprd_hwspinlock_ops, 0, SPRD_HWLOCKS_NUM);
+	if (ret) {
+		dev_err(&pdev->dev, "hwspinlock register failed!\n");
+		pm_runtime_disable(&pdev->dev);
+		clk_disable_unprepare(sprd_hwlock->clk);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int sprd_hwspinlock_remove(struct platform_device *pdev)
+{
+	struct sprd_hwspinlock_dev *sprd_hwlock = platform_get_drvdata(pdev);
+	int ret;
+
+	ret = hwspin_lock_unregister(&sprd_hwlock->bank);
+	if (ret) {
+		dev_err(&pdev->dev, "hwspinlock unregister failed: %d\n", ret);
+		return ret;
+	}
+
+	pm_runtime_disable(&pdev->dev);
+	clk_disable_unprepare(sprd_hwlock->clk);
+	return 0;
+}
+
+static struct platform_driver sprd_hwspinlock_driver = {
+	.probe = sprd_hwspinlock_probe,
+	.remove = sprd_hwspinlock_remove,
+	.driver = {
+		.name = "sprd_hwspinlock",
+		.owner = THIS_MODULE,
+		.of_match_table = of_match_ptr(sprd_hwspinlock_of_match),
+	},
+};
+
+static int __init sprd_hwspinlock_init(void)
+{
+	return platform_driver_register(&sprd_hwspinlock_driver);
+}
+postcore_initcall(sprd_hwspinlock_init);
+
+static void __exit sprd_hwspinlock_exit(void)
+{
+	platform_driver_unregister(&sprd_hwspinlock_driver);
+}
+module_exit(sprd_hwspinlock_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Hardware spinlock driver for Spreadtrum");
+MODULE_AUTHOR("Baolin Wang <baolin.wang@spreadtrum.com>");
+MODULE_AUTHOR("Lanqing Liu <lanqing.liu@spreadtrum.com>");
+MODULE_AUTHOR("Long Cheng <aiden.cheng@spreadtrum.com>");