[patch 72/86] gpio: pca953x: convert to use bitmap API

Andrew Morton
2019-12-05T00:53:40Z

From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Subject: gpio: pca953x: convert to use bitmap API

Instead of customized approach convert the driver to use bitmap API.

[andriy.shevchenko@linux.intel.com: reduce stack usage in couple of functions]
Link: http://lkml.kernel.org/r/20191023153056.64262-1-andriy.shevchenko@linux.intel.com
Link: http://lkml.kernel.org/r/20191022172922.61232-11-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Cc: William Breathitt Gray <vilhelm.gray@gmail.com>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

drivers/gpio/gpio-pca953x.c | 164 ++++++++++++++--------------------
1 file changed, 70 insertions(+), 94 deletions(-)

--- a/drivers/gpio/gpio-pca953x.c~gpio-pca953x-convert-to-use-bitmap-api
+++ a/drivers/gpio/gpio-pca953x.c
@@ -9,8 +9,7 @@
*/

#include <linux/acpi.h>
-#include <linux/bits.h>
-#include <linux/bitops.h>
+#include <linux/bitmap.h>
#include <linux/gpio/driver.h>
#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
@@ -116,6 +115,7 @@ MODULE_DEVICE_TABLE(acpi, pca953x_acpi_i

#define MAX_BANK 5
#define BANK_SZ 8
+#define MAX_LINE (MAX_BANK * BANK_SZ)

#define NBANK(chip) DIV_ROUND_UP(chip->gpio_chip.ngpio, BANK_SZ)

@@ -147,10 +147,10 @@ struct pca953x_chip {

#ifdef CONFIG_GPIO_PCA953X_IRQ
struct mutex irq_lock;
- u8 irq_mask[MAX_BANK];
- u8 irq_stat[MAX_BANK];
- u8 irq_trig_raise[MAX_BANK];
- u8 irq_trig_fall[MAX_BANK];
+ DECLARE_BITMAP(irq_mask, MAX_LINE);
+ DECLARE_BITMAP(irq_stat, MAX_LINE);
+ DECLARE_BITMAP(irq_trig_raise, MAX_LINE);
+ DECLARE_BITMAP(irq_trig_fall, MAX_LINE);
struct irq_chip irq_chip;
#endif
atomic_t wakeup_path;
@@ -334,12 +334,16 @@ static u8 pca953x_recalc_addr(struct pca
return regaddr;
}

-static int pca953x_write_regs(struct pca953x_chip *chip, int reg, u8 *val)
+static int pca953x_write_regs(struct pca953x_chip *chip, int reg, unsigned long *val)
{
u8 regaddr = pca953x_recalc_addr(chip, reg, 0, true, true);
- int ret;
+ u8 value[MAX_BANK];
+ int i, ret;
+
+ for (i = 0; i < NBANK(chip); i++)
+ value[i] = bitmap_get_value8(val, i * BANK_SZ);

- ret = regmap_bulk_write(chip->regmap, regaddr, val, NBANK(chip));
+ ret = regmap_bulk_write(chip->regmap, regaddr, value, NBANK(chip));
if (ret < 0) {
dev_err(&chip->client->dev, "failed writing register\n");
return ret;
@@ -348,17 +352,21 @@ static int pca953x_write_regs(struct pca
return 0;
}

-static int pca953x_read_regs(struct pca953x_chip *chip, int reg, u8 *val)
+static int pca953x_read_regs(struct pca953x_chip *chip, int reg, unsigned long *val)
{
u8 regaddr = pca953x_recalc_addr(chip, reg, 0, false, true);
- int ret;
+ u8 value[MAX_BANK];
+ int i, ret;

- ret = regmap_bulk_read(chip->regmap, regaddr, val, NBANK(chip));
+ ret = regmap_bulk_read(chip->regmap, regaddr, value, NBANK(chip));
if (ret < 0) {
dev_err(&chip->client->dev, "failed reading register\n");
return ret;
}

+ for (i = 0; i < NBANK(chip); i++)
+ bitmap_set_value8(val, value[i], i * BANK_SZ);
+
return 0;
}

@@ -460,10 +468,7 @@ static void pca953x_gpio_set_multiple(st
unsigned long *mask, unsigned long *bits)
{
struct pca953x_chip *chip = gpiochip_get_data(gc);
- unsigned long offset;
- unsigned long bank_mask;
- int bank;
- u8 reg_val[MAX_BANK];
+ DECLARE_BITMAP(reg_val, MAX_LINE);
int ret;

mutex_lock(&chip->i2c_lock);
@@ -471,11 +476,7 @@ static void pca953x_gpio_set_multiple(st
if (ret)
goto exit;

- for_each_set_clump8(offset, bank_mask, mask, gc->ngpio) {
- bank = offset / 8;
- reg_val[bank] &= ~bank_mask;
- reg_val[bank] |= bitmap_get_value8(bits, offset) & bank_mask;
- }
+ bitmap_replace(reg_val, reg_val, bits, mask, gc->ngpio);

pca953x_write_regs(chip, chip->regs->output, reg_val);
exit:
@@ -602,10 +603,9 @@ static void pca953x_irq_bus_sync_unlock(
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct pca953x_chip *chip = gpiochip_get_data(gc);
- u8 new_irqs;
- int level, i;
- u8 invert_irq_mask[MAX_BANK];
- u8 reg_direction[MAX_BANK];
+ DECLARE_BITMAP(irq_mask, MAX_LINE);
+ DECLARE_BITMAP(reg_direction, MAX_LINE);
+ int level;

pca953x_read_regs(chip, chip->regs->direction, reg_direction);

@@ -613,25 +613,18 @@ static void pca953x_irq_bus_sync_unlock(
/* Enable latch on interrupt-enabled inputs */
pca953x_write_regs(chip, PCAL953X_IN_LATCH, chip->irq_mask);

- for (i = 0; i < NBANK(chip); i++)
- invert_irq_mask[i] = ~chip->irq_mask[i];
+ bitmap_complement(irq_mask, chip->irq_mask, gc->ngpio);

/* Unmask enabled interrupts */
- pca953x_write_regs(chip, PCAL953X_INT_MASK, invert_irq_mask);
+ pca953x_write_regs(chip, PCAL953X_INT_MASK, irq_mask);
}

+ bitmap_or(irq_mask, chip->irq_trig_fall, chip->irq_trig_raise, gc->ngpio);
+ bitmap_and(irq_mask, irq_mask, reg_direction, gc->ngpio);
+
/* Look for any newly setup interrupt */
- for (i = 0; i < NBANK(chip); i++) {
- new_irqs = chip->irq_trig_fall[i] | chip->irq_trig_raise[i];
- new_irqs &= reg_direction[i];
-
- while (new_irqs) {
- level = __ffs(new_irqs);
- pca953x_gpio_direction_input(&chip->gpio_chip,
- level + (BANK_SZ * i));
- new_irqs &= ~(1 << level);
- }
- }
+ for_each_set_bit(level, irq_mask, gc->ngpio)
+ pca953x_gpio_direction_input(&chip->gpio_chip, level);

mutex_unlock(&chip->irq_lock);
}
@@ -672,15 +665,15 @@ static void pca953x_irq_shutdown(struct
chip->irq_trig_fall[d->hwirq / BANK_SZ] &= ~mask;
}

-static bool pca953x_irq_pending(struct pca953x_chip *chip, u8 *pending)
+static bool pca953x_irq_pending(struct pca953x_chip *chip, unsigned long *pending)
{
- u8 cur_stat[MAX_BANK];
- u8 old_stat[MAX_BANK];
- bool pending_seen = false;
- bool trigger_seen = false;
- u8 trigger[MAX_BANK];
- u8 reg_direction[MAX_BANK];
- int ret, i;
+ struct gpio_chip *gc = &chip->gpio_chip;
+ DECLARE_BITMAP(reg_direction, MAX_LINE);
+ DECLARE_BITMAP(old_stat, MAX_LINE);
+ DECLARE_BITMAP(cur_stat, MAX_LINE);
+ DECLARE_BITMAP(new_stat, MAX_LINE);
+ DECLARE_BITMAP(trigger, MAX_LINE);
+ int ret;

if (chip->driver_data & PCA_PCAL) {
/* Read the current interrupt status from the device */
@@ -693,16 +686,12 @@ static bool pca953x_irq_pending(struct p
if (ret)
return false;

- for (i = 0; i < NBANK(chip); i++) {
- /* Apply filter for rising/falling edge selection */
- pending[i] = (~cur_stat[i] & chip->irq_trig_fall[i]) |
- (cur_stat[i] & chip->irq_trig_raise[i]);
- pending[i] &= trigger[i];
- if (pending[i])
- pending_seen = true;
- }
+ /* Apply filter for rising/falling edge selection */
+ bitmap_replace(new_stat, chip->irq_trig_fall, chip->irq_trig_raise, cur_stat, gc->ngpio);
+
+ bitmap_and(pending, new_stat, trigger, gc->ngpio);

- return pending_seen;
+ return !bitmap_empty(pending, gc->ngpio);
}

ret = pca953x_read_regs(chip, chip->regs->input, cur_stat);
@@ -711,51 +700,38 @@ static bool pca953x_irq_pending(struct p

/* Remove output pins from the equation */
pca953x_read_regs(chip, chip->regs->direction, reg_direction);
- for (i = 0; i < NBANK(chip); i++)
- cur_stat[i] &= reg_direction[i];

- memcpy(old_stat, chip->irq_stat, NBANK(chip));
+ bitmap_copy(old_stat, chip->irq_stat, gc->ngpio);

- for (i = 0; i < NBANK(chip); i++) {
- trigger[i] = (cur_stat[i] ^ old_stat[i]) & chip->irq_mask[i];
- if (trigger[i])
- trigger_seen = true;
- }
+ bitmap_and(new_stat, cur_stat, reg_direction, gc->ngpio);
+ bitmap_xor(cur_stat, new_stat, old_stat, gc->ngpio);
+ bitmap_and(trigger, cur_stat, chip->irq_mask, gc->ngpio);

- if (!trigger_seen)
+ if (bitmap_empty(trigger, gc->ngpio))
return false;

- memcpy(chip->irq_stat, cur_stat, NBANK(chip));
+ bitmap_copy(chip->irq_stat, new_stat, gc->ngpio);

- for (i = 0; i < NBANK(chip); i++) {
- pending[i] = (old_stat[i] & chip->irq_trig_fall[i]) |
- (cur_stat[i] & chip->irq_trig_raise[i]);
- pending[i] &= trigger[i];
- if (pending[i])
- pending_seen = true;
- }
+ bitmap_and(cur_stat, chip->irq_trig_fall, old_stat, gc->ngpio);
+ bitmap_and(old_stat, chip->irq_trig_raise, new_stat, gc->ngpio);
+ bitmap_or(new_stat, old_stat, cur_stat, gc->ngpio);
+ bitmap_and(pending, new_stat, trigger, gc->ngpio);

- return pending_seen;
+ return !bitmap_empty(pending, gc->ngpio);
}

static irqreturn_t pca953x_irq_handler(int irq, void *devid)
{
struct pca953x_chip *chip = devid;
- u8 pending[MAX_BANK];
- u8 level;
- int i;
+ struct gpio_chip *gc = &chip->gpio_chip;
+ DECLARE_BITMAP(pending, MAX_LINE);
+ int level;

if (!pca953x_irq_pending(chip, pending))
return IRQ_NONE;

- for (i = 0; i < NBANK(chip); i++) {
- while (pending[i]) {
- level = __ffs(pending[i]);
- handle_nested_irq(irq_find_mapping(chip->gpio_chip.irq.domain,
- level + (BANK_SZ * i)));
- pending[i] &= ~(1 << level);
- }
- }
+ for_each_set_bit(level, pending, gc->ngpio)
+ handle_nested_irq(irq_find_mapping(gc->irq.domain, level));

return IRQ_HANDLED;
}
@@ -765,8 +741,9 @@ static int pca953x_irq_setup(struct pca9
{
struct i2c_client *client = chip->client;
struct irq_chip *irq_chip = &chip->irq_chip;
- u8 reg_direction[MAX_BANK];
- int ret, i;
+ DECLARE_BITMAP(reg_direction, MAX_LINE);
+ DECLARE_BITMAP(irq_stat, MAX_LINE);
+ int ret;

if (!client->irq)
return 0;
@@ -777,7 +754,7 @@ static int pca953x_irq_setup(struct pca9
if (!(chip->driver_data & PCA_INT))
return 0;

- ret = pca953x_read_regs(chip, chip->regs->input, chip->irq_stat);
+ ret = pca953x_read_regs(chip, chip->regs->input, irq_stat);
if (ret)
return ret;

@@ -787,8 +764,7 @@ static int pca953x_irq_setup(struct pca9
* this purpose.
*/
pca953x_read_regs(chip, chip->regs->direction, reg_direction);
- for (i = 0; i < NBANK(chip); i++)
- chip->irq_stat[i] &= reg_direction[i];
+ bitmap_and(chip->irq_stat, irq_stat, reg_direction, chip->gpio_chip.ngpio);
mutex_init(&chip->irq_lock);

ret = devm_request_threaded_irq(&client->dev, client->irq,
@@ -840,8 +816,8 @@ static int pca953x_irq_setup(struct pca9

static int device_pca95xx_init(struct pca953x_chip *chip, u32 invert)
{
+ DECLARE_BITMAP(val, MAX_LINE);
int ret;
- u8 val[MAX_BANK];

ret = regcache_sync_region(chip->regmap, chip->regs->output,
chip->regs->output + NBANK(chip));
@@ -855,9 +831,9 @@ static int device_pca95xx_init(struct pc

/* set platform specific polarity inversion */
if (invert)
- memset(val, 0xFF, NBANK(chip));
+ bitmap_fill(val, MAX_LINE);
else
- memset(val, 0, NBANK(chip));
+ bitmap_zero(val, MAX_LINE);

ret = pca953x_write_regs(chip, chip->regs->invert, val);
out:
@@ -866,8 +842,8 @@ out:

static int device_pca957x_init(struct pca953x_chip *chip, u32 invert)
{
+ DECLARE_BITMAP(val, MAX_LINE);
int ret;
- u8 val[MAX_BANK];

ret = device_pca95xx_init(chip, invert);
if (ret)
_