linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Mathieu Poirier <mathieu.poirier@linaro.org>
To: stable@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Subject: [stable 4.19][PATCH 2/3] gpio: zynq: Report gpio direction at boot
Date: Mon, 10 Feb 2020 10:18:26 -0700	[thread overview]
Message-ID: <20200210171827.29693-3-mathieu.poirier@linaro.org> (raw)
In-Reply-To: <20200210171827.29693-1-mathieu.poirier@linaro.org>

From: Brandon Maier <Brandon.Maier@collins.com>

commit 6169005ceb8c715582eca70df3912cd2b351ede2 upstream

The Zynq's gpios can be configured by the bootloader. But Linux will
erroneously report all gpios as inputs unless we implement
get_direction().

Signed-off-by: Brandon Maier <Brandon.Maier@collins.com>
Tested-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Cc: stable <stable@vger.kernel.org> # 4.19
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
---
 drivers/gpio/gpio-zynq.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/drivers/gpio/gpio-zynq.c b/drivers/gpio/gpio-zynq.c
index a9238fb15013..5dec96155814 100644
--- a/drivers/gpio/gpio-zynq.c
+++ b/drivers/gpio/gpio-zynq.c
@@ -357,6 +357,28 @@ static int zynq_gpio_dir_out(struct gpio_chip *chip, unsigned int pin,
 	return 0;
 }
 
+/**
+ * zynq_gpio_get_direction - Read the direction of the specified GPIO pin
+ * @chip:	gpio_chip instance to be worked on
+ * @pin:	gpio pin number within the device
+ *
+ * This function returns the direction of the specified GPIO.
+ *
+ * Return: 0 for output, 1 for input
+ */
+static int zynq_gpio_get_direction(struct gpio_chip *chip, unsigned int pin)
+{
+	u32 reg;
+	unsigned int bank_num, bank_pin_num;
+	struct zynq_gpio *gpio = gpiochip_get_data(chip);
+
+	zynq_gpio_get_bank_pin(pin, &bank_num, &bank_pin_num, gpio);
+
+	reg = readl_relaxed(gpio->base_addr + ZYNQ_GPIO_DIRM_OFFSET(bank_num));
+
+	return !(reg & BIT(bank_pin_num));
+}
+
 /**
  * zynq_gpio_irq_mask - Disable the interrupts for a gpio pin
  * @irq_data:	per irq and chip data passed down to chip functions
@@ -829,6 +851,7 @@ static int zynq_gpio_probe(struct platform_device *pdev)
 	chip->free = zynq_gpio_free;
 	chip->direction_input = zynq_gpio_dir_in;
 	chip->direction_output = zynq_gpio_dir_out;
+	chip->get_direction = zynq_gpio_get_direction;
 	chip->base = of_alias_get_id(pdev->dev.of_node, "gpio");
 	chip->ngpio = gpio->p_data->ngpio;
 
-- 
2.20.1


  parent reply	other threads:[~2020-02-10 17:18 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-10 17:18 [stable 4.19][PATCH 0/3] stable: Candidates for 4.19.y Mathieu Poirier
2020-02-10 17:18 ` [stable 4.19][PATCH 1/3] serial: uartps: Add a timeout to the tx empty wait Mathieu Poirier
2020-02-10 17:18 ` Mathieu Poirier [this message]
2020-02-10 17:18 ` [stable 4.19][PATCH 3/3] spi: spi-mem: Add extra sanity checks on the op param Mathieu Poirier
2020-02-12 13:12 ` [stable 4.19][PATCH 0/3] stable: Candidates for 4.19.y Sasha Levin

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200210171827.29693-3-mathieu.poirier@linaro.org \
    --to=mathieu.poirier@linaro.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=stable@vger.kernel.org \
    --subject='Re: [stable 4.19][PATCH 2/3] gpio: zynq: Report gpio direction at boot' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).