From patchwork Thu Jul 7 12:50:16 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Subject: plat-mxc: add missing initialisation of basic_mmio_gpio shadow variables From: =?utf-8?q?Lothar_Wa=C3=9Fmann?= X-Patchwork-Id: 103650 Message-Id: <1310043016-1121-1-git-send-email-LW@KARO-electronics.de> To: linux-arm-kernel@lists.infradead.org Cc: Grant Likely , Sascha Hauer , linux-kernel@vger.kernel.org, =?utf-8?q?Lothar=20Wa=C3=9Fmann?= Date: Thu, 7 Jul 2011 14:50:16 +0200 The bgpio_init() function does not initialise the shadow register for the GPIO direction register. Thus, when configuring the first GPIO with gpio_set_direction() all other GPIOs of the same bank will be configured as inputs. Since the bgpio layer cannot know whether the register is readable, the initialisation should be done by the caller of bgpio_init(). Also, the 'data' shadow variable that is used inside basic_mmio_gpio to cache the current value of the GPIO_DR register is initialised from the GPIO_PSR register within bgpio_init(). Thus when setting the output value of a certain GPIO, the other GPIO outputs of the same bank will be set or cleared depending on the pin state of the GPIO inputs during bgpio_init(). Signed-off-by: Lothar Waßmann --- drivers/gpio/gpio-mxc.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/drivers/gpio/gpio-mxc.c b/drivers/gpio/gpio-mxc.c index b351952..f7944ca 100644 --- a/drivers/gpio/gpio-mxc.c +++ b/drivers/gpio/gpio-mxc.c @@ -337,6 +337,8 @@ static int __devinit mxc_gpio_probe(struct platform_device *pdev) goto out_iounmap; port->bgc.gc.base = pdev->id * 32; + port->bgc.dir = port->bgc.read_reg(port->bgc.reg_dir); + port->bgc.data = port->bgc.read_reg(port->bgc.reg_set); err = gpiochip_add(&port->bgc.gc); if (err)