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Subject[RESEND PATCH v4 3/3] gpio: xilinx: Utilize generic bitmap_get_value and _set_value
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 | 52 +++++++++++++++++++-------------------
1 file changed, 26 insertions(+), 26 deletions(-)

diff --git a/drivers/gpio/gpio-xilinx.c b/drivers/gpio/gpio-xilinx.c
index b411d3156e0b..512198250b02 100644
--- a/drivers/gpio/gpio-xilinx.c
+++ b/drivers/gpio/gpio-xilinx.c
@@ -18,6 +18,7 @@
#include <linux/of_platform.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>
+#include "gpiolib.h"

/* Register Offset Definitions */
#define XGPIO_DATA_OFFSET (0x0) /* Data register */
@@ -161,35 +162,34 @@ 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, flags);
+ u32 *state = chip->gpio_state;
+ unsigned int *width = chip->gpio_width;
+ DECLARE_BITMAP(old, 64);
+ DECLARE_BITMAP(new, 64);
+ DECLARE_BITMAP(changed, 64);

- /* 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, flags);
- index = xgpio_index(chip, i);
- spin_lock_irqsave(&chip->gpio_lock, 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);
- }
- }
+ spin_lock_irqsave(&chip->gpio_lock, flags);

- xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +
- index * XGPIO_CHANNEL_OFFSET, chip->gpio_state[index]);
+ /* Copy initial value of state bits into 'old' contiguously */
+ bitmap_set_value(old, 64, state[0], width[0], 0);
+ bitmap_set_value(old, 64, state[1], width[1], width[0]);
+ /* Copy value from 'old' into 'new' with mask applied */
+ bitmap_replace(new, old, bits, mask, gc->ngpio);
+
+ bitmap_from_arr32(old, state, 64);
+ /* Update 'state' */
+ state[0] = bitmap_get_value(new, 0, width[0]);
+ state[1] = bitmap_get_value(new, width[0], width[1]);
+ bitmap_from_arr32(new, state, 64);
+ /* XOR operation sets only changed bits */
+ 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_irqrestore(&chip->gpio_lock, flags);
}
--
2.29.0
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