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[4/8] gpio: pcie-idio-24: Implement get_multiple callback

Message ID 5d46c780a6e3be82e672dbd17ba70d275e35b51b.1520886945.git.vilhelm.gray@gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

William Breathitt Gray March 12, 2018, 8:49 p.m. UTC 
The ACCES I/O PCIe-IDIO-24 series of devices provides 24
optically-isolated digital inputs accessed via three 8-bit ports. Since
eight input lines are acquired on a single port input read, the
PCIe-IDIO-24 GPIO driver may improve multiple input reads by utilizing a
get_multiple callback. This patch implements the
idio_24_gpio_get_multiple function which serves as the respective
get_multiple callback.

Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
---
 drivers/gpio/gpio-pcie-idio-24.c | 63 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 63 insertions(+)

Comments

kernel test robot March 13, 2018, 2:33 p.m. UTC | #1 
Hi William,

I love your patch! Perhaps something to improve:

[auto build test WARNING on linus/master]
[also build test WARNING on v4.16-rc5 next-20180313]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/William-Breathitt-Gray/Implement-get_multiple-for-ACCES-and-PC104-drivers/20180313-202244
config: x86_64-randconfig-x014-201810 (attached as .config)
compiler: gcc-7 (Debian 7.3.0-1) 7.3.0
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

Note: it may well be a FALSE warning. FWIW you are at least aware of it now.
http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings

All warnings (new ones prefixed by >>):

   drivers//gpio/gpio-pcie-idio-24.c: In function 'idio_24_gpio_get_multiple':
>> drivers//gpio/gpio-pcie-idio-24.c:252:35: warning: 'port_state' may be used uninitialized in this function [-Wmaybe-uninitialized]
      bits[BIT_WORD(i)] |= port_state << bit_word_offset;
                           ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~

vim +/port_state +252 drivers//gpio/gpio-pcie-idio-24.c

   195	
   196	static int idio_24_gpio_get_multiple(struct gpio_chip *chip,
   197		unsigned long *mask, unsigned long *bits)
   198	{
   199		struct idio_24_gpio *const idio24gpio = gpiochip_get_data(chip);
   200		struct idio_24_gpio_reg __iomem *const reg = idio24gpio->reg;
   201		unsigned int i;
   202		const unsigned int gpio_reg_size = 8;
   203		unsigned int bit_word_offset;
   204		unsigned int bits_mask;
   205		const unsigned long reg_mask = GENMASK(gpio_reg_size, 0);
   206		unsigned long port_state;
   207		const unsigned long out_mode_mask = BIT(1);
   208	
   209		/* clear bits array to a clean slate */
   210		for (i = 0; i < chip->ngpio; i += BITS_PER_LONG)
   211			bits[i / BITS_PER_LONG] = 0;
   212	
   213		/* get bits are evaluated a gpio register size at a time */
   214		for (i = 0; i < chip->ngpio; i += gpio_reg_size) {
   215			bit_word_offset = i % BITS_PER_LONG;
   216			bits_mask = mask[BIT_WORD(i)] & (reg_mask << bit_word_offset);
   217			if (!bits_mask) {
   218				/* no get bits in this register so skip to next one */
   219				continue;
   220			}
   221	
   222			/* read bits from current gpio register */
   223			switch (i / gpio_reg_size) {
   224			case 0:
   225				port_state = ioread8(&reg->out0_7);
   226				break;
   227			case 1:
   228				port_state = ioread8(&reg->out8_15);
   229				break;
   230			case 2:
   231				port_state = ioread8(&reg->out16_23);
   232				break;
   233			case 3:
   234				port_state = ioread8(&reg->in0_7);
   235				break;
   236			case 4:
   237				port_state = ioread8(&reg->in8_15);
   238				break;
   239			case 5:
   240				port_state = ioread8(&reg->in16_23);
   241				break;
   242			case 6:
   243				/* TTL/CMOS Outputs/Inputs */
   244				if (ioread8(&reg->ctl) & out_mode_mask)
   245					port_state = ioread8(&reg->ttl_out0_7);
   246				else
   247					port_state = ioread8(&reg->ttl_in0_7);
   248				break;
   249			}
   250	
   251			/* store acquired bits */
 > 252			bits[BIT_WORD(i)] |= port_state << bit_word_offset;
   253		}
   254	
   255		return 0;
   256	}
   257	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
diff mbox

Patch

diff --git a/drivers/gpio/gpio-pcie-idio-24.c b/drivers/gpio/gpio-pcie-idio-24.c
index f666e2e69074..6efc85292c49 100644
--- a/drivers/gpio/gpio-pcie-idio-24.c
+++ b/drivers/gpio/gpio-pcie-idio-24.c
@@ -193,6 +193,68 @@  static int idio_24_gpio_get(struct gpio_chip *chip, unsigned int offset)
 	return !!(ioread8(&idio24gpio->reg->ttl_in0_7) & offset_mask);
 }
 
+static int idio_24_gpio_get_multiple(struct gpio_chip *chip,
+	unsigned long *mask, unsigned long *bits)
+{
+	struct idio_24_gpio *const idio24gpio = gpiochip_get_data(chip);
+	struct idio_24_gpio_reg __iomem *const reg = idio24gpio->reg;
+	unsigned int i;
+	const unsigned int gpio_reg_size = 8;
+	unsigned int bit_word_offset;
+	unsigned int bits_mask;
+	const unsigned long reg_mask = GENMASK(gpio_reg_size, 0);
+	unsigned long port_state;
+	const unsigned long out_mode_mask = BIT(1);
+
+	/* clear bits array to a clean slate */
+	for (i = 0; i < chip->ngpio; i += BITS_PER_LONG)
+		bits[i / BITS_PER_LONG] = 0;
+
+	/* get bits are evaluated a gpio register size at a time */
+	for (i = 0; i < chip->ngpio; i += gpio_reg_size) {
+		bit_word_offset = i % BITS_PER_LONG;
+		bits_mask = mask[BIT_WORD(i)] & (reg_mask << bit_word_offset);
+		if (!bits_mask) {
+			/* no get bits in this register so skip to next one */
+			continue;
+		}
+
+		/* read bits from current gpio register */
+		switch (i / gpio_reg_size) {
+		case 0:
+			port_state = ioread8(&reg->out0_7);
+			break;
+		case 1:
+			port_state = ioread8(&reg->out8_15);
+			break;
+		case 2:
+			port_state = ioread8(&reg->out16_23);
+			break;
+		case 3:
+			port_state = ioread8(&reg->in0_7);
+			break;
+		case 4:
+			port_state = ioread8(&reg->in8_15);
+			break;
+		case 5:
+			port_state = ioread8(&reg->in16_23);
+			break;
+		case 6:
+			/* TTL/CMOS Outputs/Inputs */
+			if (ioread8(&reg->ctl) & out_mode_mask)
+				port_state = ioread8(&reg->ttl_out0_7);
+			else
+				port_state = ioread8(&reg->ttl_in0_7);
+			break;
+		}
+
+		/* store acquired bits */
+		bits[BIT_WORD(i)] |= port_state << bit_word_offset;
+	}
+
+	return 0;
+}
+
 static void idio_24_gpio_set(struct gpio_chip *chip, unsigned int offset,
 	int value)
 {
@@ -397,6 +459,7 @@  static int idio_24_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	idio24gpio->chip.direction_input = idio_24_gpio_direction_input;
 	idio24gpio->chip.direction_output = idio_24_gpio_direction_output;
 	idio24gpio->chip.get = idio_24_gpio_get;
+	idio24gpio->chip.get_multiple = idio_24_gpio_get_multiple;
 	idio24gpio->chip.set = idio_24_gpio_set;
 
 	raw_spin_lock_init(&idio24gpio->lock);