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

[Srinivas Neeli]

Hi,

> -----Original Message-----
> From: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
> Sent: Friday, March 26, 2021 10:58 PM
> To: Michal Simek <michals@xxxxxxxxxx>
> Cc: Syed Nayyar Waris <syednwaris@xxxxxxxxx>; Srinivas Neeli
> <sneeli@xxxxxxxxxx>; Andy Shevchenko
> <andriy.shevchenko@xxxxxxxxxxxxxxx>; William Breathitt Gray
> <vilhelm.gray@xxxxxxxxx>; Arnd Bergmann <arnd@xxxxxxxx>; Robert
> Richter <rrichter@xxxxxxxxxxx>; Linus Walleij <linus.walleij@xxxxxxxxxx>;
> Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>; Andrew Morton
> <akpm@xxxxxxxxxxxxxxxxxxxx>; Zhang Rui <rui.zhang@xxxxxxxxx>; Daniel
> Lezcano <daniel.lezcano@xxxxxxxxxx>; Amit Kucheria
> <amit.kucheria@xxxxxxxxxxxxx>; Linux-Arch <linux-arch@xxxxxxxxxxxxxxx>;
> linux-gpio <linux-gpio@xxxxxxxxxxxxxxx>; LKML <linux-
> kernel@xxxxxxxxxxxxxxx>; arm-soc <linux-arm-kernel@xxxxxxxxxxxxxxxxxxx>;
> linux-pm <linux-pm@xxxxxxxxxxxxxxx>; Srinivas Goud <sgoud@xxxxxxxxxx>
> 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@xxxxxxxxxx>
> 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@xxxxxxxxxxxx>
> > > Cc: Michal Simek <michal.simek@xxxxxxxxxx>
> > > Signed-off-by: Syed Nayyar Waris <syednwaris@xxxxxxxxx>
> > > Acked-by: William Breathitt Gray <vilhelm.gray@xxxxxxxxx>
> > > ---
> > >  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