diff mbox series

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

Message ID 5041c8cfc423f046ca9cf4f8f0a8bd03552ab6ea.1608963095.git.syednwaris@gmail.com
State New
Headers show
Series Introduce the for_each_set_clump macro | expand

Commit Message

Syed Nayyar Waris Dec. 26, 2020, 6:44 a.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: William Breathitt Gray <vilhelm.gray@gmail.com>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Syed Nayyar Waris <syednwaris@gmail.com>
---
 drivers/gpio/gpio-xilinx.c | 66 +++++++++++++++++++-------------------
 1 file changed, 33 insertions(+), 33 deletions(-)

Comments

Linus Walleij Dec. 27, 2020, 9:29 p.m. UTC | #1 
On Sat, Dec 26, 2020 at 7:44 AM Syed Nayyar Waris <syednwaris@gmail.com> 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 <vilhelm.gray@gmail.com>
> Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> Cc: Michal Simek <michal.simek@xilinx.com>
> Signed-off-by: Syed Nayyar Waris <syednwaris@gmail.com>

(...)

> +#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
Michal Simek Jan. 5, 2021, 11:04 a.m. UTC | #2 
Hi, +Srinivas,

On 27. 12. 20 22:29, Linus Walleij wrote:
> On Sat, Dec 26, 2020 at 7:44 AM Syed Nayyar Waris <syednwaris@gmail.com> 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 <vilhelm.gray@gmail.com>
>> Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
>> Cc: Michal Simek <michal.simek@xilinx.com>
>> Signed-off-by: Syed Nayyar Waris <syednwaris@gmail.com>
> 
> (...)
> 
>> +#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
diff mbox series

Patch

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 <linux/io.h>
 #include <linux/gpio/driver.h>
 #include <linux/slab.h>
+#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(&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);
 }
 
 /**
@@ -292,6 +293,7 @@  static int xgpio_probe(struct platform_device *pdev)
 		chip->gpio_width[0] = 32;
 
 	spin_lock_init(&chip->gpio_lock[0]);
+	spin_lock_init(&chip->gpio_lock[1]);
 
 	if (of_property_read_u32(np, "xlnx,is-dual", &is_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",
 					 &chip->gpio_width[1]))
 			chip->gpio_width[1] = 32;
-
-		spin_lock_init(&chip->gpio_lock[1]);
 	}
 
 	chip->gc.base = -1;