diff mbox series

[v3,3/3] gpio: xilinx: Utilize generic bitmap_get_value and _set_value

Message ID 4c259d34b5943bf384fd3cb0d98eccf798a34f0f.1615038553.git.syednwaris@gmail.com
State New
Headers show
Series Introduce the for_each_set_nbits macro | expand

Commit Message

Syed Nayyar Waris March 6, 2021, 2:06 p.m. UTC
This patch reimplements the xgpio_set_multiple() function in
drivers/gpio/gpio-xilinx.c to use the new generic functions:
bitmap_get_value() and bitmap_set_value(). The code is now simpler
to read and understand. Moreover, instead of looping for each bit
in xgpio_set_multiple() function, now we can check each channel at
a time and save cycles.

Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Syed Nayyar Waris <syednwaris@gmail.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
---
 drivers/gpio/gpio-xilinx.c | 63 +++++++++++++++++++-------------------
 1 file changed, 32 insertions(+), 31 deletions(-)

Comments

Michal Simek March 8, 2021, 7:13 a.m. UTC | #1
On 3/6/21 3:06 PM, Syed Nayyar Waris wrote:
> This patch reimplements the xgpio_set_multiple() function in

> drivers/gpio/gpio-xilinx.c to use the new generic functions:

> bitmap_get_value() and bitmap_set_value(). The code is now simpler

> to read and understand. Moreover, instead of looping for each bit

> in xgpio_set_multiple() function, now we can check each channel at

> a time and save cycles.

> 

> Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>

> Cc: Michal Simek <michal.simek@xilinx.com>

> Signed-off-by: Syed Nayyar Waris <syednwaris@gmail.com>

> Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>

> ---

>  drivers/gpio/gpio-xilinx.c | 63 +++++++++++++++++++-------------------

>  1 file changed, 32 insertions(+), 31 deletions(-)

> 

> diff --git a/drivers/gpio/gpio-xilinx.c b/drivers/gpio/gpio-xilinx.c

> index be539381fd82..8445e69cf37b 100644

> --- a/drivers/gpio/gpio-xilinx.c

> +++ b/drivers/gpio/gpio-xilinx.c

> @@ -15,6 +15,7 @@

>  #include <linux/of_device.h>

>  #include <linux/of_platform.h>

>  #include <linux/slab.h>

> +#include "gpiolib.h"

>  

>  /* Register Offset Definitions */

>  #define XGPIO_DATA_OFFSET   (0x0)	/* Data register  */

> @@ -141,37 +142,37 @@ static void xgpio_set_multiple(struct gpio_chip *gc, unsigned long *mask,

>  {

>  	unsigned long flags;

>  	struct xgpio_instance *chip = gpiochip_get_data(gc);

> -	int index = xgpio_index(chip, 0);

> -	int offset, i;

> -

> -	spin_lock_irqsave(&chip->gpio_lock[index], flags);

> -

> -	/* Write to GPIO signals */

> -	for (i = 0; i < gc->ngpio; i++) {

> -		if (*mask == 0)

> -			break;

> -		/* Once finished with an index write it out to the register */

> -		if (index !=  xgpio_index(chip, i)) {

> -			xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +

> -				       index * XGPIO_CHANNEL_OFFSET,

> -				       chip->gpio_state[index]);

> -			spin_unlock_irqrestore(&chip->gpio_lock[index], flags);

> -			index =  xgpio_index(chip, i);

> -			spin_lock_irqsave(&chip->gpio_lock[index], flags);

> -		}

> -		if (__test_and_clear_bit(i, mask)) {

> -			offset =  xgpio_offset(chip, i);

> -			if (test_bit(i, bits))

> -				chip->gpio_state[index] |= BIT(offset);

> -			else

> -				chip->gpio_state[index] &= ~BIT(offset);

> -		}

> -	}

> -

> -	xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +

> -		       index * XGPIO_CHANNEL_OFFSET, chip->gpio_state[index]);

> -

> -	spin_unlock_irqrestore(&chip->gpio_lock[index], flags);

> +	u32 *const state = chip->gpio_state;

> +	unsigned int *const width = chip->gpio_width;

> +

> +	DECLARE_BITMAP(old, 64);

> +	DECLARE_BITMAP(new, 64);

> +	DECLARE_BITMAP(changed, 64);

> +

> +	spin_lock_irqsave(&chip->gpio_lock[0], flags);

> +	spin_lock(&chip->gpio_lock[1]);

> +

> +	bitmap_set_value(old, 64, state[0], width[0], 0);

> +	bitmap_set_value(old, 64, state[1], width[1], width[0]);

> +	bitmap_replace(new, old, bits, mask, gc->ngpio);

> +

> +	bitmap_set_value(old, 64, state[0], 32, 0);

> +	bitmap_set_value(old, 64, state[1], 32, 32);

> +	state[0] = bitmap_get_value(new, 0, width[0]);

> +	state[1] = bitmap_get_value(new, width[0], width[1]);

> +	bitmap_set_value(new, 64, state[0], 32, 0);

> +	bitmap_set_value(new, 64, state[1], 32, 32);

> +	bitmap_xor(changed, old, new, 64);

> +

> +	if (((u32 *)changed)[0])

> +		xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET,

> +				state[0]);

> +	if (((u32 *)changed)[1])

> +		xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +

> +				XGPIO_CHANNEL_OFFSET, state[1]);

> +

> +	spin_unlock(&chip->gpio_lock[1]);

> +	spin_unlock_irqrestore(&chip->gpio_lock[0], flags);

>  }

>  

>  /**

> 


Srinivas N: Can you please test this code?

Thanks,
Michal
Bartosz Golaszewski March 26, 2021, 5:27 p.m. UTC | #2
On Mon, Mar 8, 2021 at 8:13 AM Michal Simek <michal.simek@xilinx.com> wrote:
>
>
>
> On 3/6/21 3:06 PM, Syed Nayyar Waris wrote:
> > This patch reimplements the xgpio_set_multiple() function in
> > drivers/gpio/gpio-xilinx.c to use the new generic functions:
> > bitmap_get_value() and bitmap_set_value(). The code is now simpler
> > to read and understand. Moreover, instead of looping for each bit
> > in xgpio_set_multiple() function, now we can check each channel at
> > a time and save cycles.
> >
> > Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> > Cc: Michal Simek <michal.simek@xilinx.com>
> > Signed-off-by: Syed Nayyar Waris <syednwaris@gmail.com>
> > Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
> > ---
> >  drivers/gpio/gpio-xilinx.c | 63 +++++++++++++++++++-------------------
> >  1 file changed, 32 insertions(+), 31 deletions(-)
> >
> > diff --git a/drivers/gpio/gpio-xilinx.c b/drivers/gpio/gpio-xilinx.c
> > index be539381fd82..8445e69cf37b 100644
> > --- a/drivers/gpio/gpio-xilinx.c
> > +++ b/drivers/gpio/gpio-xilinx.c
> > @@ -15,6 +15,7 @@
> >  #include <linux/of_device.h>
> >  #include <linux/of_platform.h>
> >  #include <linux/slab.h>
> > +#include "gpiolib.h"
> >
> >  /* Register Offset Definitions */
> >  #define XGPIO_DATA_OFFSET   (0x0)    /* Data register  */
> > @@ -141,37 +142,37 @@ static void xgpio_set_multiple(struct gpio_chip *gc, unsigned long *mask,
> >  {
> >       unsigned long flags;
> >       struct xgpio_instance *chip = gpiochip_get_data(gc);
> > -     int index = xgpio_index(chip, 0);
> > -     int offset, i;
> > -
> > -     spin_lock_irqsave(&chip->gpio_lock[index], flags);
> > -
> > -     /* Write to GPIO signals */
> > -     for (i = 0; i < gc->ngpio; i++) {
> > -             if (*mask == 0)
> > -                     break;
> > -             /* Once finished with an index write it out to the register */
> > -             if (index !=  xgpio_index(chip, i)) {
> > -                     xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +
> > -                                    index * XGPIO_CHANNEL_OFFSET,
> > -                                    chip->gpio_state[index]);
> > -                     spin_unlock_irqrestore(&chip->gpio_lock[index], flags);
> > -                     index =  xgpio_index(chip, i);
> > -                     spin_lock_irqsave(&chip->gpio_lock[index], flags);
> > -             }
> > -             if (__test_and_clear_bit(i, mask)) {
> > -                     offset =  xgpio_offset(chip, i);
> > -                     if (test_bit(i, bits))
> > -                             chip->gpio_state[index] |= BIT(offset);
> > -                     else
> > -                             chip->gpio_state[index] &= ~BIT(offset);
> > -             }
> > -     }
> > -
> > -     xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +
> > -                    index * XGPIO_CHANNEL_OFFSET, chip->gpio_state[index]);
> > -
> > -     spin_unlock_irqrestore(&chip->gpio_lock[index], flags);
> > +     u32 *const state = chip->gpio_state;
> > +     unsigned int *const width = chip->gpio_width;
> > +
> > +     DECLARE_BITMAP(old, 64);
> > +     DECLARE_BITMAP(new, 64);
> > +     DECLARE_BITMAP(changed, 64);
> > +
> > +     spin_lock_irqsave(&chip->gpio_lock[0], flags);
> > +     spin_lock(&chip->gpio_lock[1]);
> > +
> > +     bitmap_set_value(old, 64, state[0], width[0], 0);
> > +     bitmap_set_value(old, 64, state[1], width[1], width[0]);
> > +     bitmap_replace(new, old, bits, mask, gc->ngpio);
> > +
> > +     bitmap_set_value(old, 64, state[0], 32, 0);
> > +     bitmap_set_value(old, 64, state[1], 32, 32);
> > +     state[0] = bitmap_get_value(new, 0, width[0]);
> > +     state[1] = bitmap_get_value(new, width[0], width[1]);
> > +     bitmap_set_value(new, 64, state[0], 32, 0);
> > +     bitmap_set_value(new, 64, state[1], 32, 32);
> > +     bitmap_xor(changed, old, new, 64);
> > +
> > +     if (((u32 *)changed)[0])
> > +             xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET,
> > +                             state[0]);
> > +     if (((u32 *)changed)[1])
> > +             xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +
> > +                             XGPIO_CHANNEL_OFFSET, state[1]);
> > +
> > +     spin_unlock(&chip->gpio_lock[1]);
> > +     spin_unlock_irqrestore(&chip->gpio_lock[0], flags);
> >  }
> >
> >  /**
> >
>
> Srinivas N: Can you please test this code?
>
> Thanks,
> Michal

Hey, any chance of getting that Tested-by?

Bart
Andy Shevchenko March 26, 2021, 6:02 p.m. UTC | #3
On Sat, Mar 6, 2021 at 4:08 PM Syed Nayyar Waris <syednwaris@gmail.com> wrote:

> +       bitmap_set_value(old, 64, state[0], 32, 0);
> +       bitmap_set_value(old, 64, state[1], 32, 32);

Isn't it effectively bitnap_from_arr32() ?

> +       bitmap_set_value(new, 64, state[0], 32, 0);
> +       bitmap_set_value(new, 64, state[1], 32, 32);

Ditto.
William Breathitt Gray March 27, 2021, 12:02 p.m. UTC | #4
On Sat, Mar 27, 2021 at 09:29:26AM +0200, Andy Shevchenko wrote:
> On Saturday, March 27, 2021, Syed Nayyar Waris <syednwaris@gmail.com> wrote:
> 
> > On Fri, Mar 26, 2021 at 11:32 PM Andy Shevchenko
> > <andy.shevchenko@gmail.com> wrote:
> > >
> > > On Sat, Mar 6, 2021 at 4:08 PM Syed Nayyar Waris <syednwaris@gmail.com>
> > wrote:
> > >
> > > > +       bitmap_set_value(old, 64, state[0], 32, 0);
> > > > +       bitmap_set_value(old, 64, state[1], 32, 32);
> > >
> > > Isn't it effectively bitnap_from_arr32() ?
> > >
> > > > +       bitmap_set_value(new, 64, state[0], 32, 0);
> > > > +       bitmap_set_value(new, 64, state[1], 32, 32);
> > >
> > > Ditto.
> > >
> > > --
> > > With Best Regards,
> > > Andy Shevchenko
> >
> > Hi Andy,
> >
> > With bitmap_set_value() we are also specifying the offset (or start)
> > position too. so that the remainder of the array remains unaffected. I
> > think it would not be feasible to use bitmap_from/to_arr32()  here.
> 
> 
> You have hard coded start and nbits parameters to 32. How is it not the
> same?

Would these four lines become something like this:

	bitmap_from_arr32(old, state, 64);
	...
	bitmap_from_arr32(new, state, 64);

Sincerely,

William Breathitt Gray
Andy Shevchenko March 27, 2021, 4:35 p.m. UTC | #5
On Sat, Mar 27, 2021 at 2:02 PM William Breathitt Gray
<vilhelm.gray@gmail.com> wrote:
> On Sat, Mar 27, 2021 at 09:29:26AM +0200, Andy Shevchenko wrote:
> > On Saturday, March 27, 2021, Syed Nayyar Waris <syednwaris@gmail.com> wrote:
> > > On Fri, Mar 26, 2021 at 11:32 PM Andy Shevchenko
> > > <andy.shevchenko@gmail.com> wrote:
> > > > On Sat, Mar 6, 2021 at 4:08 PM Syed Nayyar Waris <syednwaris@gmail.com>
> > > wrote:
> > > >
> > > > > +       bitmap_set_value(old, 64, state[0], 32, 0);
> > > > > +       bitmap_set_value(old, 64, state[1], 32, 32);
> > > >
> > > > Isn't it effectively bitnap_from_arr32() ?
> > > >
> > > > > +       bitmap_set_value(new, 64, state[0], 32, 0);
> > > > > +       bitmap_set_value(new, 64, state[1], 32, 32);
> > > >
> > > > Ditto.

> > > With bitmap_set_value() we are also specifying the offset (or start)
> > > position too. so that the remainder of the array remains unaffected. I
> > > think it would not be feasible to use bitmap_from/to_arr32()  here.
> >
> >
> > You have hard coded start and nbits parameters to 32. How is it not the
> > same?
>
> Would these four lines become something like this:
>
>         bitmap_from_arr32(old, state, 64);
>         ...
>         bitmap_from_arr32(new, state, 64);

This is my understanding, but I might miss something. I mean driver
specifics that make my proposal incorrect.
Andy Shevchenko March 29, 2021, 3:24 p.m. UTC | #6
On Sat, Mar 06, 2021 at 07:36:30PM +0530, Syed Nayyar Waris wrote:
> This patch reimplements the xgpio_set_multiple() function in

> drivers/gpio/gpio-xilinx.c to use the new generic functions:

> bitmap_get_value() and bitmap_set_value(). The code is now simpler

> to read and understand. Moreover, instead of looping for each bit

> in xgpio_set_multiple() function, now we can check each channel at

> a time and save cycles.


...

> +	u32 *const state = chip->gpio_state;


Looking at this... What's the point of the const here?

Am I right that this tells: pointer is a const, while the data underneath
can be modified?

> +	unsigned int *const width = chip->gpio_width;


Ditto.

Putting const:s here and there for sake of the const is not good practice.
It makes code harder to read.

-- 
With Best Regards,
Andy Shevchenko
Srinivas Neeli March 31, 2021, 3:26 p.m. UTC | #7
Hi,

> -----Original Message-----

> From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

> Sent: Friday, March 26, 2021 10:58 PM

> To: Michal Simek <michals@xilinx.com>

> Cc: Syed Nayyar Waris <syednwaris@gmail.com>; Srinivas Neeli

> <sneeli@xilinx.com>; Andy Shevchenko

> <andriy.shevchenko@linux.intel.com>; William Breathitt Gray

> <vilhelm.gray@gmail.com>; Arnd Bergmann <arnd@arndb.de>; Robert

> Richter <rrichter@marvell.com>; Linus Walleij <linus.walleij@linaro.org>;

> Masahiro Yamada <yamada.masahiro@socionext.com>; Andrew Morton

> <akpm@linux-foundation.org>; Zhang Rui <rui.zhang@intel.com>; Daniel

> Lezcano <daniel.lezcano@linaro.org>; Amit Kucheria

> <amit.kucheria@verdurent.com>; Linux-Arch <linux-arch@vger.kernel.org>;

> linux-gpio <linux-gpio@vger.kernel.org>; LKML <linux-

> kernel@vger.kernel.org>; arm-soc <linux-arm-kernel@lists.infradead.org>;

> linux-pm <linux-pm@vger.kernel.org>; Srinivas Goud <sgoud@xilinx.com>

> Subject: Re: [PATCH v3 3/3] gpio: xilinx: Utilize generic bitmap_get_value and

> _set_value

> 

> On Mon, Mar 8, 2021 at 8:13 AM Michal Simek <michal.simek@xilinx.com>

> wrote:

> >

> >

> >

> > On 3/6/21 3:06 PM, Syed Nayyar Waris wrote:

> > > This patch reimplements the xgpio_set_multiple() function in

> > > drivers/gpio/gpio-xilinx.c to use the new generic functions:

> > > bitmap_get_value() and bitmap_set_value(). The code is now simpler

> > > to read and understand. Moreover, instead of looping for each bit in

> > > xgpio_set_multiple() function, now we can check each channel at a

> > > time and save cycles.

> > >

> > > Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>

> > > Cc: Michal Simek <michal.simek@xilinx.com>

> > > Signed-off-by: Syed Nayyar Waris <syednwaris@gmail.com>

> > > Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>

> > > ---

> > >  drivers/gpio/gpio-xilinx.c | 63

> > > +++++++++++++++++++-------------------

> > >  1 file changed, 32 insertions(+), 31 deletions(-)

> > >

> > > diff --git a/drivers/gpio/gpio-xilinx.c b/drivers/gpio/gpio-xilinx.c

> > > index be539381fd82..8445e69cf37b 100644

> > > --- a/drivers/gpio/gpio-xilinx.c

> > > +++ b/drivers/gpio/gpio-xilinx.c

> > > @@ -15,6 +15,7 @@

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

> > >  #include <linux/of_platform.h>

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

> > > +#include "gpiolib.h"

> > >

> > >  /* Register Offset Definitions */

> > >  #define XGPIO_DATA_OFFSET   (0x0)    /* Data register  */

> > > @@ -141,37 +142,37 @@ static void xgpio_set_multiple(struct

> > > gpio_chip *gc, unsigned long *mask,  {

> > >       unsigned long flags;

> > >       struct xgpio_instance *chip = gpiochip_get_data(gc);

> > > -     int index = xgpio_index(chip, 0);

> > > -     int offset, i;

> > > -

> > > -     spin_lock_irqsave(&chip->gpio_lock[index], flags);

> > > -

> > > -     /* Write to GPIO signals */

> > > -     for (i = 0; i < gc->ngpio; i++) {

> > > -             if (*mask == 0)

> > > -                     break;

> > > -             /* Once finished with an index write it out to the register */

> > > -             if (index !=  xgpio_index(chip, i)) {

> > > -                     xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +

> > > -                                    index * XGPIO_CHANNEL_OFFSET,

> > > -                                    chip->gpio_state[index]);

> > > -                     spin_unlock_irqrestore(&chip->gpio_lock[index], flags);

> > > -                     index =  xgpio_index(chip, i);

> > > -                     spin_lock_irqsave(&chip->gpio_lock[index], flags);

> > > -             }

> > > -             if (__test_and_clear_bit(i, mask)) {

> > > -                     offset =  xgpio_offset(chip, i);

> > > -                     if (test_bit(i, bits))

> > > -                             chip->gpio_state[index] |= BIT(offset);

> > > -                     else

> > > -                             chip->gpio_state[index] &= ~BIT(offset);

> > > -             }

> > > -     }

> > > -

> > > -     xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +

> > > -                    index * XGPIO_CHANNEL_OFFSET, chip->gpio_state[index]);

> > > -

> > > -     spin_unlock_irqrestore(&chip->gpio_lock[index], flags);

> > > +     u32 *const state = chip->gpio_state;

> > > +     unsigned int *const width = chip->gpio_width;

> > > +

> > > +     DECLARE_BITMAP(old, 64);

> > > +     DECLARE_BITMAP(new, 64);

> > > +     DECLARE_BITMAP(changed, 64);

> > > +

> > > +     spin_lock_irqsave(&chip->gpio_lock[0], flags);

> > > +     spin_lock(&chip->gpio_lock[1]);

> > > +

> > > +     bitmap_set_value(old, 64, state[0], width[0], 0);

> > > +     bitmap_set_value(old, 64, state[1], width[1], width[0]);

> > > +     bitmap_replace(new, old, bits, mask, gc->ngpio);

> > > +

> > > +     bitmap_set_value(old, 64, state[0], 32, 0);

> > > +     bitmap_set_value(old, 64, state[1], 32, 32);

> > > +     state[0] = bitmap_get_value(new, 0, width[0]);

> > > +     state[1] = bitmap_get_value(new, width[0], width[1]);

> > > +     bitmap_set_value(new, 64, state[0], 32, 0);

> > > +     bitmap_set_value(new, 64, state[1], 32, 32);

> > > +     bitmap_xor(changed, old, new, 64);

> > > +

> > > +     if (((u32 *)changed)[0])

> > > +             xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET,

> > > +                             state[0]);

> > > +     if (((u32 *)changed)[1])

> > > +             xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +

> > > +                             XGPIO_CHANNEL_OFFSET, state[1]);

> > > +

> > > +     spin_unlock(&chip->gpio_lock[1]);

> > > +     spin_unlock_irqrestore(&chip->gpio_lock[0], flags);

> > >  }

> > >

> > >  /**

> > >

> >

> > Srinivas N: Can you please test this code?

> >

> > Thanks,

> > Michal

> 

> Hey, any chance of getting that Tested-by?

I tested patches with few modifications in code (spin_lock handling and merge conflict).
functionality wise it's working fine.

> 

> Bart
Syed Nayyar Waris April 1, 2021, 11:15 a.m. UTC | #8
On Wed, Mar 31, 2021 at 8:56 PM Srinivas Neeli <sneeli@xilinx.com> wrote:
>

> Hi,

>

> > -----Original Message-----

> > From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

> > Sent: Friday, March 26, 2021 10:58 PM

> > To: Michal Simek <michals@xilinx.com>

> > Cc: Syed Nayyar Waris <syednwaris@gmail.com>; Srinivas Neeli

> > <sneeli@xilinx.com>; Andy Shevchenko

> > <andriy.shevchenko@linux.intel.com>; William Breathitt Gray

> > <vilhelm.gray@gmail.com>; Arnd Bergmann <arnd@arndb.de>; Robert

> > Richter <rrichter@marvell.com>; Linus Walleij <linus.walleij@linaro.org>;

> > Masahiro Yamada <yamada.masahiro@socionext.com>; Andrew Morton

> > <akpm@linux-foundation.org>; Zhang Rui <rui.zhang@intel.com>; Daniel

> > Lezcano <daniel.lezcano@linaro.org>; Amit Kucheria

> > <amit.kucheria@verdurent.com>; Linux-Arch <linux-arch@vger.kernel.org>;

> > linux-gpio <linux-gpio@vger.kernel.org>; LKML <linux-

> > kernel@vger.kernel.org>; arm-soc <linux-arm-kernel@lists.infradead.org>;

> > linux-pm <linux-pm@vger.kernel.org>; Srinivas Goud <sgoud@xilinx.com>

> > Subject: Re: [PATCH v3 3/3] gpio: xilinx: Utilize generic bitmap_get_value and

> > _set_value

> >

> > On Mon, Mar 8, 2021 at 8:13 AM Michal Simek <michal.simek@xilinx.com>

> > wrote:

> > >

> > >

> > >

> > > On 3/6/21 3:06 PM, Syed Nayyar Waris wrote:

> > > > This patch reimplements the xgpio_set_multiple() function in

> > > > drivers/gpio/gpio-xilinx.c to use the new generic functions:

> > > > bitmap_get_value() and bitmap_set_value(). The code is now simpler

> > > > to read and understand. Moreover, instead of looping for each bit in

> > > > xgpio_set_multiple() function, now we can check each channel at a

> > > > time and save cycles.

> > > >

> > > > Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>

> > > > Cc: Michal Simek <michal.simek@xilinx.com>

> > > > Signed-off-by: Syed Nayyar Waris <syednwaris@gmail.com>

> > > > Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>

> > > > ---

> > > >  drivers/gpio/gpio-xilinx.c | 63

> > > > +++++++++++++++++++-------------------

> > > >  1 file changed, 32 insertions(+), 31 deletions(-)

> > > >

> > > > diff --git a/drivers/gpio/gpio-xilinx.c b/drivers/gpio/gpio-xilinx.c

> > > > index be539381fd82..8445e69cf37b 100644

> > > > --- a/drivers/gpio/gpio-xilinx.c

> > > > +++ b/drivers/gpio/gpio-xilinx.c

> > > > @@ -15,6 +15,7 @@

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

> > > >  #include <linux/of_platform.h>

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

> > > > +#include "gpiolib.h"

> > > >

> > > >  /* Register Offset Definitions */

> > > >  #define XGPIO_DATA_OFFSET   (0x0)    /* Data register  */

> > > > @@ -141,37 +142,37 @@ static void xgpio_set_multiple(struct

> > > > gpio_chip *gc, unsigned long *mask,  {

> > > >       unsigned long flags;

> > > >       struct xgpio_instance *chip = gpiochip_get_data(gc);

> > > > -     int index = xgpio_index(chip, 0);

> > > > -     int offset, i;

> > > > -

> > > > -     spin_lock_irqsave(&chip->gpio_lock[index], flags);

> > > > -

> > > > -     /* Write to GPIO signals */

> > > > -     for (i = 0; i < gc->ngpio; i++) {

> > > > -             if (*mask == 0)

> > > > -                     break;

> > > > -             /* Once finished with an index write it out to the register */

> > > > -             if (index !=  xgpio_index(chip, i)) {

> > > > -                     xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +

> > > > -                                    index * XGPIO_CHANNEL_OFFSET,

> > > > -                                    chip->gpio_state[index]);

> > > > -                     spin_unlock_irqrestore(&chip->gpio_lock[index], flags);

> > > > -                     index =  xgpio_index(chip, i);

> > > > -                     spin_lock_irqsave(&chip->gpio_lock[index], flags);

> > > > -             }

> > > > -             if (__test_and_clear_bit(i, mask)) {

> > > > -                     offset =  xgpio_offset(chip, i);

> > > > -                     if (test_bit(i, bits))

> > > > -                             chip->gpio_state[index] |= BIT(offset);

> > > > -                     else

> > > > -                             chip->gpio_state[index] &= ~BIT(offset);

> > > > -             }

> > > > -     }

> > > > -

> > > > -     xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +

> > > > -                    index * XGPIO_CHANNEL_OFFSET, chip->gpio_state[index]);

> > > > -

> > > > -     spin_unlock_irqrestore(&chip->gpio_lock[index], flags);

> > > > +     u32 *const state = chip->gpio_state;

> > > > +     unsigned int *const width = chip->gpio_width;

> > > > +

> > > > +     DECLARE_BITMAP(old, 64);

> > > > +     DECLARE_BITMAP(new, 64);

> > > > +     DECLARE_BITMAP(changed, 64);

> > > > +

> > > > +     spin_lock_irqsave(&chip->gpio_lock[0], flags);

> > > > +     spin_lock(&chip->gpio_lock[1]);

> > > > +

> > > > +     bitmap_set_value(old, 64, state[0], width[0], 0);

> > > > +     bitmap_set_value(old, 64, state[1], width[1], width[0]);

> > > > +     bitmap_replace(new, old, bits, mask, gc->ngpio);

> > > > +

> > > > +     bitmap_set_value(old, 64, state[0], 32, 0);

> > > > +     bitmap_set_value(old, 64, state[1], 32, 32);

> > > > +     state[0] = bitmap_get_value(new, 0, width[0]);

> > > > +     state[1] = bitmap_get_value(new, width[0], width[1]);

> > > > +     bitmap_set_value(new, 64, state[0], 32, 0);

> > > > +     bitmap_set_value(new, 64, state[1], 32, 32);

> > > > +     bitmap_xor(changed, old, new, 64);

> > > > +

> > > > +     if (((u32 *)changed)[0])

> > > > +             xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET,

> > > > +                             state[0]);

> > > > +     if (((u32 *)changed)[1])

> > > > +             xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +

> > > > +                             XGPIO_CHANNEL_OFFSET, state[1]);

> > > > +

> > > > +     spin_unlock(&chip->gpio_lock[1]);

> > > > +     spin_unlock_irqrestore(&chip->gpio_lock[0], flags);

> > > >  }

> > > >

> > > >  /**

> > > >

> > >

> > > Srinivas N: Can you please test this code?

> > >

> > > Thanks,

> > > Michal

> >

> > Hey, any chance of getting that Tested-by?

> I tested patches with few modifications in code (spin_lock handling and merge conflict).

> functionality wise it's working fine.

>

> >

> > Bart


Hi Bartosz,

May I please know the URL of the tree that you are using. I had been
using the tree below for submitting this patchset on GPIO to you.
https://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio.git

I think I am using the wrong tree. On which tree should I base my
patches on for my next  (v4) submission? Should I use the tree below?
:
https://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux.git

Regards
Syed Nayyar Waris
Bartosz Golaszewski April 1, 2021, 12:51 p.m. UTC | #9
On Thu, Apr 1, 2021 at 1:16 PM Syed Nayyar Waris <syednwaris@gmail.com> wrote:
>

> On Wed, Mar 31, 2021 at 8:56 PM Srinivas Neeli <sneeli@xilinx.com> wrote:

> >

> > Hi,

> >

> > > -----Original Message-----

> > > From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

> > > Sent: Friday, March 26, 2021 10:58 PM

> > > To: Michal Simek <michals@xilinx.com>

> > > Cc: Syed Nayyar Waris <syednwaris@gmail.com>; Srinivas Neeli

> > > <sneeli@xilinx.com>; Andy Shevchenko

> > > <andriy.shevchenko@linux.intel.com>; William Breathitt Gray

> > > <vilhelm.gray@gmail.com>; Arnd Bergmann <arnd@arndb.de>; Robert

> > > Richter <rrichter@marvell.com>; Linus Walleij <linus.walleij@linaro.org>;

> > > Masahiro Yamada <yamada.masahiro@socionext.com>; Andrew Morton

> > > <akpm@linux-foundation.org>; Zhang Rui <rui.zhang@intel.com>; Daniel

> > > Lezcano <daniel.lezcano@linaro.org>; Amit Kucheria

> > > <amit.kucheria@verdurent.com>; Linux-Arch <linux-arch@vger.kernel.org>;

> > > linux-gpio <linux-gpio@vger.kernel.org>; LKML <linux-

> > > kernel@vger.kernel.org>; arm-soc <linux-arm-kernel@lists.infradead.org>;

> > > linux-pm <linux-pm@vger.kernel.org>; Srinivas Goud <sgoud@xilinx.com>

> > > Subject: Re: [PATCH v3 3/3] gpio: xilinx: Utilize generic bitmap_get_value and

> > > _set_value

> > >

> > > On Mon, Mar 8, 2021 at 8:13 AM Michal Simek <michal.simek@xilinx.com>

> > > wrote:

> > > >

> > > >

> > > >

> > > > On 3/6/21 3:06 PM, Syed Nayyar Waris wrote:

> > > > > This patch reimplements the xgpio_set_multiple() function in

> > > > > drivers/gpio/gpio-xilinx.c to use the new generic functions:

> > > > > bitmap_get_value() and bitmap_set_value(). The code is now simpler

> > > > > to read and understand. Moreover, instead of looping for each bit in

> > > > > xgpio_set_multiple() function, now we can check each channel at a

> > > > > time and save cycles.

> > > > >

> > > > > Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>

> > > > > Cc: Michal Simek <michal.simek@xilinx.com>

> > > > > Signed-off-by: Syed Nayyar Waris <syednwaris@gmail.com>

> > > > > Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>

> > > > > ---

> > > > >  drivers/gpio/gpio-xilinx.c | 63

> > > > > +++++++++++++++++++-------------------

> > > > >  1 file changed, 32 insertions(+), 31 deletions(-)

> > > > >

> > > > > diff --git a/drivers/gpio/gpio-xilinx.c b/drivers/gpio/gpio-xilinx.c

> > > > > index be539381fd82..8445e69cf37b 100644

> > > > > --- a/drivers/gpio/gpio-xilinx.c

> > > > > +++ b/drivers/gpio/gpio-xilinx.c

> > > > > @@ -15,6 +15,7 @@

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

> > > > >  #include <linux/of_platform.h>

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

> > > > > +#include "gpiolib.h"

> > > > >

> > > > >  /* Register Offset Definitions */

> > > > >  #define XGPIO_DATA_OFFSET   (0x0)    /* Data register  */

> > > > > @@ -141,37 +142,37 @@ static void xgpio_set_multiple(struct

> > > > > gpio_chip *gc, unsigned long *mask,  {

> > > > >       unsigned long flags;

> > > > >       struct xgpio_instance *chip = gpiochip_get_data(gc);

> > > > > -     int index = xgpio_index(chip, 0);

> > > > > -     int offset, i;

> > > > > -

> > > > > -     spin_lock_irqsave(&chip->gpio_lock[index], flags);

> > > > > -

> > > > > -     /* Write to GPIO signals */

> > > > > -     for (i = 0; i < gc->ngpio; i++) {

> > > > > -             if (*mask == 0)

> > > > > -                     break;

> > > > > -             /* Once finished with an index write it out to the register */

> > > > > -             if (index !=  xgpio_index(chip, i)) {

> > > > > -                     xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +

> > > > > -                                    index * XGPIO_CHANNEL_OFFSET,

> > > > > -                                    chip->gpio_state[index]);

> > > > > -                     spin_unlock_irqrestore(&chip->gpio_lock[index], flags);

> > > > > -                     index =  xgpio_index(chip, i);

> > > > > -                     spin_lock_irqsave(&chip->gpio_lock[index], flags);

> > > > > -             }

> > > > > -             if (__test_and_clear_bit(i, mask)) {

> > > > > -                     offset =  xgpio_offset(chip, i);

> > > > > -                     if (test_bit(i, bits))

> > > > > -                             chip->gpio_state[index] |= BIT(offset);

> > > > > -                     else

> > > > > -                             chip->gpio_state[index] &= ~BIT(offset);

> > > > > -             }

> > > > > -     }

> > > > > -

> > > > > -     xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +

> > > > > -                    index * XGPIO_CHANNEL_OFFSET, chip->gpio_state[index]);

> > > > > -

> > > > > -     spin_unlock_irqrestore(&chip->gpio_lock[index], flags);

> > > > > +     u32 *const state = chip->gpio_state;

> > > > > +     unsigned int *const width = chip->gpio_width;

> > > > > +

> > > > > +     DECLARE_BITMAP(old, 64);

> > > > > +     DECLARE_BITMAP(new, 64);

> > > > > +     DECLARE_BITMAP(changed, 64);

> > > > > +

> > > > > +     spin_lock_irqsave(&chip->gpio_lock[0], flags);

> > > > > +     spin_lock(&chip->gpio_lock[1]);

> > > > > +

> > > > > +     bitmap_set_value(old, 64, state[0], width[0], 0);

> > > > > +     bitmap_set_value(old, 64, state[1], width[1], width[0]);

> > > > > +     bitmap_replace(new, old, bits, mask, gc->ngpio);

> > > > > +

> > > > > +     bitmap_set_value(old, 64, state[0], 32, 0);

> > > > > +     bitmap_set_value(old, 64, state[1], 32, 32);

> > > > > +     state[0] = bitmap_get_value(new, 0, width[0]);

> > > > > +     state[1] = bitmap_get_value(new, width[0], width[1]);

> > > > > +     bitmap_set_value(new, 64, state[0], 32, 0);

> > > > > +     bitmap_set_value(new, 64, state[1], 32, 32);

> > > > > +     bitmap_xor(changed, old, new, 64);

> > > > > +

> > > > > +     if (((u32 *)changed)[0])

> > > > > +             xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET,

> > > > > +                             state[0]);

> > > > > +     if (((u32 *)changed)[1])

> > > > > +             xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +

> > > > > +                             XGPIO_CHANNEL_OFFSET, state[1]);

> > > > > +

> > > > > +     spin_unlock(&chip->gpio_lock[1]);

> > > > > +     spin_unlock_irqrestore(&chip->gpio_lock[0], flags);

> > > > >  }

> > > > >

> > > > >  /**

> > > > >

> > > >

> > > > Srinivas N: Can you please test this code?

> > > >

> > > > Thanks,

> > > > Michal

> > >

> > > Hey, any chance of getting that Tested-by?

> > I tested patches with few modifications in code (spin_lock handling and merge conflict).

> > functionality wise it's working fine.

> >

> > >

> > > Bart

>

> Hi Bartosz,

>

> May I please know the URL of the tree that you are using. I had been

> using the tree below for submitting this patchset on GPIO to you.

> https://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio.git

>

> I think I am using the wrong tree. On which tree should I base my

> patches on for my next  (v4) submission? Should I use the tree below?

> :

> https://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux.git

>

> Regards

> Syed Nayyar Waris


Yes this is the one. Please address new issues raised by reviewers.

Bart
Syed Nayyar Waris April 1, 2021, 5:47 p.m. UTC | #10
On Mon, Mar 29, 2021 at 8:54 PM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
>
> On Sat, Mar 06, 2021 at 07:36:30PM +0530, Syed Nayyar Waris wrote:
> > This patch reimplements the xgpio_set_multiple() function in
> > drivers/gpio/gpio-xilinx.c to use the new generic functions:
> > bitmap_get_value() and bitmap_set_value(). The code is now simpler
> > to read and understand. Moreover, instead of looping for each bit
> > in xgpio_set_multiple() function, now we can check each channel at
> > a time and save cycles.
>
> ...
>
> > +     u32 *const state = chip->gpio_state;
>
> Looking at this... What's the point of the const here?
>
> Am I right that this tells: pointer is a const, while the data underneath
> can be modified?
>
> > +     unsigned int *const width = chip->gpio_width;
>
> Ditto.
>
> Putting const:s here and there for sake of the const is not good practice.
> It makes code harder to read.
>
> --
> With Best Regards,
> Andy Shevchenko
>
Okay. I will incorporate your comments in my next submission. Thank You.

Regards
Syed Nayyar Waris
Syed Nayyar Waris April 1, 2021, 5:50 p.m. UTC | #11
On Sat, Mar 27, 2021 at 10:05 PM Andy Shevchenko
<andy.shevchenko@gmail.com> wrote:
>
> On Sat, Mar 27, 2021 at 2:02 PM William Breathitt Gray
> <vilhelm.gray@gmail.com> wrote:
> > On Sat, Mar 27, 2021 at 09:29:26AM +0200, Andy Shevchenko wrote:
> > > On Saturday, March 27, 2021, Syed Nayyar Waris <syednwaris@gmail.com> wrote:
> > > > On Fri, Mar 26, 2021 at 11:32 PM Andy Shevchenko
> > > > <andy.shevchenko@gmail.com> wrote:
> > > > > On Sat, Mar 6, 2021 at 4:08 PM Syed Nayyar Waris <syednwaris@gmail.com>
> > > > wrote:
> > > > >
> > > > > > +       bitmap_set_value(old, 64, state[0], 32, 0);
> > > > > > +       bitmap_set_value(old, 64, state[1], 32, 32);
> > > > >
> > > > > Isn't it effectively bitnap_from_arr32() ?
> > > > >
> > > > > > +       bitmap_set_value(new, 64, state[0], 32, 0);
> > > > > > +       bitmap_set_value(new, 64, state[1], 32, 32);
> > > > >
> > > > > Ditto.
>
> > > > With bitmap_set_value() we are also specifying the offset (or start)
> > > > position too. so that the remainder of the array remains unaffected. I
> > > > think it would not be feasible to use bitmap_from/to_arr32()  here.
> > >
> > >
> > > You have hard coded start and nbits parameters to 32. How is it not the
> > > same?
> >
> > Would these four lines become something like this:
> >
> >         bitmap_from_arr32(old, state, 64);
> >         ...
> >         bitmap_from_arr32(new, state, 64);
>
> This is my understanding, but I might miss something. I mean driver
> specifics that make my proposal incorrect.
>
> --
> With Best Regards,
> Andy Shevchenko

I initially (incorrectly) thought that all of the bitmap_set_value()
statements have to be replaced. But now I realised, only those
specific bitmap_set_value() calls containing 32 bits width have to
replaced.

I will incorporate the above review comments in my next v4 submission.

Regards
Syed Nayyar Waris
Syed Nayyar Waris April 2, 2021, 10:07 a.m. UTC | #12
On Mon, Mar 29, 2021 at 8:54 PM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
>

> On Sat, Mar 06, 2021 at 07:36:30PM +0530, Syed Nayyar Waris wrote:

> > This patch reimplements the xgpio_set_multiple() function in

> > drivers/gpio/gpio-xilinx.c to use the new generic functions:

> > bitmap_get_value() and bitmap_set_value(). The code is now simpler

> > to read and understand. Moreover, instead of looping for each bit

> > in xgpio_set_multiple() function, now we can check each channel at

> > a time and save cycles.

>

> ...

>

> > +     u32 *const state = chip->gpio_state;

>

> Looking at this... What's the point of the const here?

>

> Am I right that this tells: pointer is a const, while the data underneath

> can be modified?


Yes you are right and the data underneath can be modified.
I have removed the 'const' in v4

>

> > +     unsigned int *const width = chip->gpio_width;

>

> Ditto.

>

> Putting const:s here and there for sake of the const is not good practice.

> It makes code harder to read.


Okay.

>

> --

> With Best Regards,

> Andy Shevchenko

>

>
diff mbox series

Patch

diff --git a/drivers/gpio/gpio-xilinx.c b/drivers/gpio/gpio-xilinx.c
index be539381fd82..8445e69cf37b 100644
--- a/drivers/gpio/gpio-xilinx.c
+++ b/drivers/gpio/gpio-xilinx.c
@@ -15,6 +15,7 @@ 
 #include <linux/of_device.h>
 #include <linux/of_platform.h>
 #include <linux/slab.h>
+#include "gpiolib.h"
 
 /* Register Offset Definitions */
 #define XGPIO_DATA_OFFSET   (0x0)	/* Data register  */
@@ -141,37 +142,37 @@  static void xgpio_set_multiple(struct gpio_chip *gc, unsigned long *mask,
 {
 	unsigned long flags;
 	struct xgpio_instance *chip = gpiochip_get_data(gc);
-	int index = xgpio_index(chip, 0);
-	int offset, i;
-
-	spin_lock_irqsave(&chip->gpio_lock[index], flags);
-
-	/* Write to GPIO signals */
-	for (i = 0; i < gc->ngpio; i++) {
-		if (*mask == 0)
-			break;
-		/* Once finished with an index write it out to the register */
-		if (index !=  xgpio_index(chip, i)) {
-			xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +
-				       index * XGPIO_CHANNEL_OFFSET,
-				       chip->gpio_state[index]);
-			spin_unlock_irqrestore(&chip->gpio_lock[index], flags);
-			index =  xgpio_index(chip, i);
-			spin_lock_irqsave(&chip->gpio_lock[index], flags);
-		}
-		if (__test_and_clear_bit(i, mask)) {
-			offset =  xgpio_offset(chip, i);
-			if (test_bit(i, bits))
-				chip->gpio_state[index] |= BIT(offset);
-			else
-				chip->gpio_state[index] &= ~BIT(offset);
-		}
-	}
-
-	xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +
-		       index * XGPIO_CHANNEL_OFFSET, chip->gpio_state[index]);
-
-	spin_unlock_irqrestore(&chip->gpio_lock[index], flags);
+	u32 *const state = chip->gpio_state;
+	unsigned int *const width = chip->gpio_width;
+
+	DECLARE_BITMAP(old, 64);
+	DECLARE_BITMAP(new, 64);
+	DECLARE_BITMAP(changed, 64);
+
+	spin_lock_irqsave(&chip->gpio_lock[0], flags);
+	spin_lock(&chip->gpio_lock[1]);
+
+	bitmap_set_value(old, 64, state[0], width[0], 0);
+	bitmap_set_value(old, 64, state[1], width[1], width[0]);
+	bitmap_replace(new, old, bits, mask, gc->ngpio);
+
+	bitmap_set_value(old, 64, state[0], 32, 0);
+	bitmap_set_value(old, 64, state[1], 32, 32);
+	state[0] = bitmap_get_value(new, 0, width[0]);
+	state[1] = bitmap_get_value(new, width[0], width[1]);
+	bitmap_set_value(new, 64, state[0], 32, 0);
+	bitmap_set_value(new, 64, state[1], 32, 32);
+	bitmap_xor(changed, old, new, 64);
+
+	if (((u32 *)changed)[0])
+		xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET,
+				state[0]);
+	if (((u32 *)changed)[1])
+		xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +
+				XGPIO_CHANNEL_OFFSET, state[1]);
+
+	spin_unlock(&chip->gpio_lock[1]);
+	spin_unlock_irqrestore(&chip->gpio_lock[0], flags);
 }
 
 /**