From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Shevchenko Subject: Re: [PATCH 3/8] gpio: pci-idio-16: Implement get_multiple callback Date: Tue, 13 Mar 2018 18:04:33 +0200 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: William Breathitt Gray Cc: Linus Walleij , "open list:GPIO SUBSYSTEM" , Linux Kernel Mailing List , linux-iio@vger.kernel.org List-Id: linux-gpio@vger.kernel.org On Mon, Mar 12, 2018 at 10:49 PM, William Breathitt Gray wrote: > +static int idio_16_gpio_get_multiple(struct gpio_chip *chip, > + unsigned long *mask, unsigned long *bits) > +{ > + /* clear bits array to a clean slate */ > + for (i = 0; i < chip->ngpio; i += BITS_PER_LONG) > + bits[i / BITS_PER_LONG] = 0; bitmap_clear() or bitmap_zero() > + /* 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; > + } for_each_set_bit() ? > + /* store acquired bits */ > + bits[BIT_WORD(i)] |= port_state << bit_word_offset; __set_bit() __clear_bit() We have bitmap API for *ages*. Is it too hard to check? -- With Best Regards, Andy Shevchenko