[PATCH v2 3/3] gpio: xilinx: Utilize generic bitmap_get_value and _set_value

Syed Nayyar Waris
2021-02-12T13:23:50Z

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 | 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);
}

/**
--
2.29.0