From: Srinivas Neeli <srinivas.neeli@xilinx.com> To: linus.walleij@linaro.org, bgolaszewski@baylibre.com, michal.simek@xilinx.com, shubhrajyoti.datta@xilinx.com Cc: linux-gpio@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, git@xilinx.com Subject: [PATCH 2/8] gpio: zynq: protect direction in/out with a spinlock Date: Thu, 26 Dec 2019 17:42:12 +0530 [thread overview] Message-ID: <1577362338-28744-3-git-send-email-srinivas.neeli@xilinx.com> (raw) In-Reply-To: <1577362338-28744-1-git-send-email-srinivas.neeli@xilinx.com> From: Glenn Langedock <Glenn.Langedock@barco.com> Fix race condition when changing the direction (in/out) of the GPIO pin. The read-modify-write sequence (as coded in the driver) isn't atomic and requires synchronization (spinlock). Signed-off-by: Glenn Langedock <Glenn.Langedock@barco.com> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Srinivas Neeli <srinivas.neeli@xilinx.com> --- drivers/gpio/gpio-zynq.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/gpio/gpio-zynq.c b/drivers/gpio/gpio-zynq.c index 05ba16fffdad..9c8b8a397a26 100644 --- a/drivers/gpio/gpio-zynq.c +++ b/drivers/gpio/gpio-zynq.c @@ -10,6 +10,7 @@ #include <linux/gpio/driver.h> #include <linux/init.h> #include <linux/interrupt.h> +#include <linux/spinlock.h> #include <linux/io.h> #include <linux/module.h> #include <linux/platform_device.h> @@ -116,6 +117,7 @@ struct gpio_regs { * @irq: interrupt for the GPIO device * @p_data: pointer to platform data * @context: context registers + * @dirlock: lock used for direction in/out synchronization */ struct zynq_gpio { struct gpio_chip chip; @@ -124,6 +126,7 @@ struct zynq_gpio { int irq; const struct zynq_platform_data *p_data; struct gpio_regs context; + spinlock_t dirlock; /*lock used for direction in/out synchronization */ }; /** @@ -297,6 +300,7 @@ static int zynq_gpio_dir_in(struct gpio_chip *chip, unsigned int pin) { u32 reg; unsigned int bank_num, bank_pin_num; + unsigned long flags; struct zynq_gpio *gpio = gpiochip_get_data(chip); zynq_gpio_get_bank_pin(pin, &bank_num, &bank_pin_num, gpio); @@ -310,9 +314,11 @@ static int zynq_gpio_dir_in(struct gpio_chip *chip, unsigned int pin) return -EINVAL; /* clear the bit in direction mode reg to set the pin as input */ + spin_lock_irqsave(&gpio->dirlock, flags); reg = readl_relaxed(gpio->base_addr + ZYNQ_GPIO_DIRM_OFFSET(bank_num)); reg &= ~BIT(bank_pin_num); writel_relaxed(reg, gpio->base_addr + ZYNQ_GPIO_DIRM_OFFSET(bank_num)); + spin_unlock_irqrestore(&gpio->dirlock, flags); return 0; } @@ -334,11 +340,13 @@ static int zynq_gpio_dir_out(struct gpio_chip *chip, unsigned int pin, { u32 reg; unsigned int bank_num, bank_pin_num; + unsigned long flags; struct zynq_gpio *gpio = gpiochip_get_data(chip); zynq_gpio_get_bank_pin(pin, &bank_num, &bank_pin_num, gpio); /* set the GPIO pin as output */ + spin_lock_irqsave(&gpio->dirlock, flags); reg = readl_relaxed(gpio->base_addr + ZYNQ_GPIO_DIRM_OFFSET(bank_num)); reg |= BIT(bank_pin_num); writel_relaxed(reg, gpio->base_addr + ZYNQ_GPIO_DIRM_OFFSET(bank_num)); @@ -347,6 +355,7 @@ static int zynq_gpio_dir_out(struct gpio_chip *chip, unsigned int pin, reg = readl_relaxed(gpio->base_addr + ZYNQ_GPIO_OUTEN_OFFSET(bank_num)); reg |= BIT(bank_pin_num); writel_relaxed(reg, gpio->base_addr + ZYNQ_GPIO_OUTEN_OFFSET(bank_num)); + spin_unlock_irqrestore(&gpio->dirlock, flags); /* set the state of the pin */ zynq_gpio_set_value(chip, pin, state); @@ -885,6 +894,8 @@ static int zynq_gpio_probe(struct platform_device *pdev) return ret; } + spin_lock_init(&gpio->dirlock); + pm_runtime_set_active(&pdev->dev); pm_runtime_enable(&pdev->dev); ret = pm_runtime_get_sync(&pdev->dev); -- 2.7.4
WARNING: multiple messages have this Message-ID (diff)
From: Srinivas Neeli <srinivas.neeli@xilinx.com> To: linus.walleij@linaro.org, bgolaszewski@baylibre.com, michal.simek@xilinx.com, shubhrajyoti.datta@xilinx.com Cc: linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, git@xilinx.com Subject: [PATCH 2/8] gpio: zynq: protect direction in/out with a spinlock Date: Thu, 26 Dec 2019 17:42:12 +0530 [thread overview] Message-ID: <1577362338-28744-3-git-send-email-srinivas.neeli@xilinx.com> (raw) In-Reply-To: <1577362338-28744-1-git-send-email-srinivas.neeli@xilinx.com> From: Glenn Langedock <Glenn.Langedock@barco.com> Fix race condition when changing the direction (in/out) of the GPIO pin. The read-modify-write sequence (as coded in the driver) isn't atomic and requires synchronization (spinlock). Signed-off-by: Glenn Langedock <Glenn.Langedock@barco.com> Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Srinivas Neeli <srinivas.neeli@xilinx.com> --- drivers/gpio/gpio-zynq.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/gpio/gpio-zynq.c b/drivers/gpio/gpio-zynq.c index 05ba16fffdad..9c8b8a397a26 100644 --- a/drivers/gpio/gpio-zynq.c +++ b/drivers/gpio/gpio-zynq.c @@ -10,6 +10,7 @@ #include <linux/gpio/driver.h> #include <linux/init.h> #include <linux/interrupt.h> +#include <linux/spinlock.h> #include <linux/io.h> #include <linux/module.h> #include <linux/platform_device.h> @@ -116,6 +117,7 @@ struct gpio_regs { * @irq: interrupt for the GPIO device * @p_data: pointer to platform data * @context: context registers + * @dirlock: lock used for direction in/out synchronization */ struct zynq_gpio { struct gpio_chip chip; @@ -124,6 +126,7 @@ struct zynq_gpio { int irq; const struct zynq_platform_data *p_data; struct gpio_regs context; + spinlock_t dirlock; /*lock used for direction in/out synchronization */ }; /** @@ -297,6 +300,7 @@ static int zynq_gpio_dir_in(struct gpio_chip *chip, unsigned int pin) { u32 reg; unsigned int bank_num, bank_pin_num; + unsigned long flags; struct zynq_gpio *gpio = gpiochip_get_data(chip); zynq_gpio_get_bank_pin(pin, &bank_num, &bank_pin_num, gpio); @@ -310,9 +314,11 @@ static int zynq_gpio_dir_in(struct gpio_chip *chip, unsigned int pin) return -EINVAL; /* clear the bit in direction mode reg to set the pin as input */ + spin_lock_irqsave(&gpio->dirlock, flags); reg = readl_relaxed(gpio->base_addr + ZYNQ_GPIO_DIRM_OFFSET(bank_num)); reg &= ~BIT(bank_pin_num); writel_relaxed(reg, gpio->base_addr + ZYNQ_GPIO_DIRM_OFFSET(bank_num)); + spin_unlock_irqrestore(&gpio->dirlock, flags); return 0; } @@ -334,11 +340,13 @@ static int zynq_gpio_dir_out(struct gpio_chip *chip, unsigned int pin, { u32 reg; unsigned int bank_num, bank_pin_num; + unsigned long flags; struct zynq_gpio *gpio = gpiochip_get_data(chip); zynq_gpio_get_bank_pin(pin, &bank_num, &bank_pin_num, gpio); /* set the GPIO pin as output */ + spin_lock_irqsave(&gpio->dirlock, flags); reg = readl_relaxed(gpio->base_addr + ZYNQ_GPIO_DIRM_OFFSET(bank_num)); reg |= BIT(bank_pin_num); writel_relaxed(reg, gpio->base_addr + ZYNQ_GPIO_DIRM_OFFSET(bank_num)); @@ -347,6 +355,7 @@ static int zynq_gpio_dir_out(struct gpio_chip *chip, unsigned int pin, reg = readl_relaxed(gpio->base_addr + ZYNQ_GPIO_OUTEN_OFFSET(bank_num)); reg |= BIT(bank_pin_num); writel_relaxed(reg, gpio->base_addr + ZYNQ_GPIO_OUTEN_OFFSET(bank_num)); + spin_unlock_irqrestore(&gpio->dirlock, flags); /* set the state of the pin */ zynq_gpio_set_value(chip, pin, state); @@ -885,6 +894,8 @@ static int zynq_gpio_probe(struct platform_device *pdev) return ret; } + spin_lock_init(&gpio->dirlock); + pm_runtime_set_active(&pdev->dev); pm_runtime_enable(&pdev->dev); ret = pm_runtime_get_sync(&pdev->dev); -- 2.7.4 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2019-12-26 12:13 UTC|newest] Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-12-26 12:12 [PATCH 0/8] gpio: zynq: Update on gpio-zynq driver Srinivas Neeli 2019-12-26 12:12 ` Srinivas Neeli 2019-12-26 12:12 ` [PATCH 1/8] gpio: zynq: Fix for bug in zynq_gpio_restore_context API Srinivas Neeli 2019-12-26 12:12 ` Srinivas Neeli 2020-01-07 10:25 ` Linus Walleij 2020-01-07 10:25 ` Linus Walleij 2019-12-26 12:12 ` Srinivas Neeli [this message] 2019-12-26 12:12 ` [PATCH 2/8] gpio: zynq: protect direction in/out with a spinlock Srinivas Neeli 2020-01-02 17:40 ` Bartosz Golaszewski 2020-01-02 17:40 ` Bartosz Golaszewski 2019-12-26 12:12 ` [PATCH 3/8] dt-bindings: gpio: Add binding for Versal gpio Srinivas Neeli 2019-12-26 12:12 ` Srinivas Neeli 2019-12-26 12:12 ` [PATCH 4/8] devicetree-binding: Add pmc gpio node Srinivas Neeli 2019-12-26 12:12 ` Srinivas Neeli 2019-12-26 12:12 ` [PATCH 5/8] gpio: zynq: Add Versal support Srinivas Neeli 2019-12-26 12:12 ` Srinivas Neeli 2020-01-02 17:41 ` Bartosz Golaszewski 2020-01-02 17:41 ` Bartosz Golaszewski 2019-12-26 12:12 ` [PATCH 6/8] gpio: zynq: Disable the irq if it is not a wakeup source Srinivas Neeli 2019-12-26 12:12 ` Srinivas Neeli 2019-12-26 12:12 ` [PATCH 7/8] gpio: zynq: Add pmc gpio support Srinivas Neeli 2019-12-26 12:12 ` Srinivas Neeli 2020-01-02 17:55 ` Bartosz Golaszewski 2020-01-02 17:55 ` Bartosz Golaszewski 2019-12-26 12:12 ` [PATCH 8/8] gpio: zynq: Remove error prints in EPROBE_DEFER Srinivas Neeli 2019-12-26 12:12 ` Srinivas Neeli
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=1577362338-28744-3-git-send-email-srinivas.neeli@xilinx.com \ --to=srinivas.neeli@xilinx.com \ --cc=bgolaszewski@baylibre.com \ --cc=git@xilinx.com \ --cc=linus.walleij@linaro.org \ --cc=linux-arm-kernel@lists.infradead.org \ --cc=linux-gpio@vger.kernel.org \ --cc=linux-kernel@vger.kernel.org \ --cc=michal.simek@xilinx.com \ --cc=shubhrajyoti.datta@xilinx.com \ /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: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.