From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Nikolaus Schaller" Subject: [PATCH v7 3/3] gpio: pca953x: fix address calculation for pcal6524 Date: Thu, 17 May 2018 06:59:49 +0200 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org To: galak@codeaurora.org, andy.shevchenko@gmail.com, Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Linus Walleij , Alexandre Courbot Cc: devicetree@vger.kernel.org, linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org, letux-kernel@openphoenux.org, kernel@pyra-handheld.com, "H. Nikolaus Schaller" List-Id: linux-gpio@vger.kernel.org The register constants are so far defined in a way that they fit for the pcal9555a when shifted by the number of banks, i.e. are multiplied by 2 in the accessor function. Now, the pcal6524 has 3 banks which means the relative offset is multiplied by 4 for the standard registers. Simply applying the bit shift to the extended registers gives a wrong result, since the base offset is already included in the offset. Therefore, we have to add code to the 24 bit accessor functions that adjusts the register number for these exended registers. The formula finally used was developed and proposed by Andy Shevchenko . Suggested-by: Andy Shevchenko Signed-off-by: H. Nikolaus Schaller --- drivers/gpio/gpio-pca953x.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c index c682921d7019..4ad553f4e41f 100644 --- a/drivers/gpio/gpio-pca953x.c +++ b/drivers/gpio/gpio-pca953x.c @@ -222,9 +222,11 @@ static int pca957x_write_regs_16(struct pca953x_chip *chip, int reg, u8 *val) static int pca953x_write_regs_24(struct pca953x_chip *chip, int reg, u8 *val) { int bank_shift = fls((chip->gpio_chip.ngpio - 1) / BANK_SZ); + int addr = (reg & PCAL_GPIO_MASK) << bank_shift; + int pinctrl = (reg & PCAL_PINCTRL_MASK) << 1; return i2c_smbus_write_i2c_block_data(chip->client, - (reg << bank_shift) | REG_ADDR_AI, + pinctrl | addr | REG_ADDR_AI, NBANK(chip), val); } @@ -264,9 +266,11 @@ static int pca953x_read_regs_16(struct pca953x_chip *chip, int reg, u8 *val) static int pca953x_read_regs_24(struct pca953x_chip *chip, int reg, u8 *val) { int bank_shift = fls((chip->gpio_chip.ngpio - 1) / BANK_SZ); + int addr = (reg & PCAL_GPIO_MASK) << bank_shift; + int pinctrl = (reg & PCAL_PINCTRL_MASK) << 1; return i2c_smbus_read_i2c_block_data(chip->client, - (reg << bank_shift) | REG_ADDR_AI, + pinctrl | addr | REG_ADDR_AI, NBANK(chip), val); } -- 2.12.2