Re: [PATCH 4/5] gpio: xilinx: Utilize generic bitmap_get_value and _set_value

2021-01-05 Thread Michal Simek
Hi, +Srinivas,

On 27. 12. 20 22:29, Linus Walleij wrote:
> On Sat, Dec 26, 2020 at 7:44 AM 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: William Breathitt Gray 
>> Cc: Bartosz Golaszewski 
>> Cc: Michal Simek 
>> Signed-off-by: Syed Nayyar Waris 
> 
> (...)
> 
>> +#include <../drivers/gpio/clump_bits.h>
> 
> What is this?
> 
> Isn't a simple
> 
> #include "clump_bits.h"
> 
> enough?
> 
> We need an ACK from the Xilinx people that they think this
> actually improves the readability and maintainability of their
> driver.

Srinivas is going to send some patches against this driver. That's why
please take a look if both of these changes are fitting together.

Thanks,
Michal


Re: [PATCH 4/5] gpio: xilinx: Utilize generic bitmap_get_value and _set_value

2020-12-27 Thread Linus Walleij
On Sat, Dec 26, 2020 at 7:44 AM 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: William Breathitt Gray 
> Cc: Bartosz Golaszewski 
> Cc: Michal Simek 
> Signed-off-by: Syed Nayyar Waris 

(...)

> +#include <../drivers/gpio/clump_bits.h>

What is this?

Isn't a simple

#include "clump_bits.h"

enough?

We need an ACK from the Xilinx people that they think this
actually improves the readability and maintainability of their
driver.

Yours,
Linus Walleij


[PATCH 4/5] gpio: xilinx: Utilize generic bitmap_get_value and _set_value

2020-12-25 Thread Syed Nayyar Waris
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: William Breathitt Gray 
Cc: Bartosz Golaszewski 
Cc: Michal Simek 
Signed-off-by: Syed Nayyar Waris 
---
 drivers/gpio/gpio-xilinx.c | 66 +++---
 1 file changed, 33 insertions(+), 33 deletions(-)

diff --git a/drivers/gpio/gpio-xilinx.c b/drivers/gpio/gpio-xilinx.c
index 67f9f82e0db0..d565fbf128b7 100644
--- a/drivers/gpio/gpio-xilinx.c
+++ b/drivers/gpio/gpio-xilinx.c
@@ -14,6 +14,7 @@
 #include 
 #include 
 #include 
+#include <../drivers/gpio/clump_bits.h>
 
 /* Register Offset Definitions */
 #define XGPIO_DATA_OFFSET   (0x0)  /* Data register  */
@@ -138,37 +139,37 @@ 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(>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(>gpio_lock[index], flags);
-   index =  xgpio_index(chip, i);
-   spin_lock_irqsave(>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(>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(>gpio_lock[0], flags);
+   spin_lock(>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(>gpio_lock[1]);
+   spin_unlock_irqrestore(>gpio_lock[0], flags);
 }
 
 /**
@@ -292,6 +293,7 @@ static int xgpio_probe(struct platform_device *pdev)
chip->gpio_width[0] = 32;
 
spin_lock_init(>gpio_lock[0]);
+   spin_lock_init(>gpio_lock[1]);
 
if (of_property_read_u32(np, "xlnx,is-dual", _dual))
is_dual = 0;
@@ -313,8 +315,6 @@ static int xgpio_probe(struct platform_device *pdev)
if (of_property_read_u32(np, "xlnx,gpio2-width",
 >gpio_width[1]))
chip->gpio_width[1] = 32;
-
-   spin_lock_init(>gpio_lock[1]);
}
 
chip->gc.base = -1;
-- 
2.29.0