gpio: pca953x: Rewrite ->get_multiple() function

The commit 96d7c7b3e654 ("gpio: gpio-pca953x, Add get_multiple function")
basically did everything wrong from style and code reuse perspective, i.e.
- it didn't utilize existing PCA953x internal helpers
- it didn't utilize bitmap API
- it misses the point that ilog2(), besides that BANK_SFT is useless,
  can be used in macros
- it has indentation issues.

Rewrite the function completely.

Cc: Paul Thomas <pthomas8589@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
index 60ae18e..41be681 100644 (file)
--- a/drivers/gpio/gpio-pca953x.c
+++ b/drivers/gpio/gpio-pca953x.c
@@ -115,7 +115,6 @@ MODULE_DEVICE_TABLE(acpi, pca953x_acpi_ids);
 
 #define MAX_BANK 5
 #define BANK_SZ 8
-#define BANK_SFT 3 /* ilog2(BANK_SZ) */
 #define MAX_LINE       (MAX_BANK * BANK_SZ)
 
 #define NBANK(chip) DIV_ROUND_UP(chip->gpio_chip.ngpio, BANK_SZ)
@@ -469,38 +468,20 @@ static int pca953x_gpio_get_direction(struct gpio_chip *gc, unsigned off)
 }
 
 static int pca953x_gpio_get_multiple(struct gpio_chip *gc,
-                                     unsigned long *mask, unsigned long *bits)
+                                    unsigned long *mask, unsigned long *bits)
 {
        struct pca953x_chip *chip = gpiochip_get_data(gc);
-       unsigned int reg_val;
-       int offset, value, i, ret = 0;
-       u8 inreg;
+       DECLARE_BITMAP(reg_val, MAX_LINE);
+       int ret;
 
-       /* Force offset outside the range of i so that
-        * at least the first relevant register is read
-        */
-       offset = gc->ngpio;
-       for_each_set_bit(i, mask, gc->ngpio) {
-               /* whenever i goes into a new bank update inreg
-                * and read the register
-                */
-               if ((offset >> BANK_SFT) != (i >> BANK_SFT)) {
-                       offset = i;
-                       inreg = pca953x_recalc_addr(chip, chip->regs->input,
-                                                   offset, true, false);
-                       mutex_lock(&chip->i2c_lock);
-                       ret = regmap_read(chip->regmap, inreg, &reg_val);
-                       mutex_unlock(&chip->i2c_lock);
-                       if (ret < 0)
-                               return ret;
-               }
-               /* reg_val is relative to the last read byte,
-                * so only shift the relative bits
-                */
-               value = (reg_val >> (i % 8)) & 0x01;
-               __assign_bit(i, bits, value);
-       }
-       return ret;
+       mutex_lock(&chip->i2c_lock);
+       ret = pca953x_read_regs(chip, chip->regs->input, reg_val);
+       mutex_unlock(&chip->i2c_lock);
+       if (ret)
+               return ret;
+
+       bitmap_replace(bits, bits, reg_val, mask, gc->ngpio);
+       return 0;
 }
 
 static void pca953x_gpio_set_multiple(struct gpio_chip *gc,