| Message ID | 20210816115953.72533-1-andriy.shevchenko@linux.intel.com |
|---|---|
| Headers | show |
| Series | gpio: mlxbf2: Introduce proper interrupt handling | expand |
On Mon, Aug 16, 2021 at 3:01 PM Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote: > > This is just a WIP / TODO series based on the discussion [1]. > I hope nVidia will finish it and fix the initial problem sooner than later. > > Bart, Linus, First 4 patches may be directly applied to the tree (they are > at least compile-tested, but I believe they won't change any functionality. > > Patch 5 is some stubs that should have been done in the driver. > Patch 6 is follow up removal of custom GPIO IRQ handling from > Mellanox GBE driver. Both of them are quite far from finishing, > but it's a start for nVidia to develop and test proper solution. > > In any case, I will probably sent end this week the ACPI IRQ abuse > part from the GBE driver (I won't touch OF path). > > ARs for nVidia: > 0) review this series; > 1) properly develop GPIO driver; > 2) replace custom code with correct one; > 3) send the work for review to GPIO and ACPI maintainers (basically list > of this series). > > On my side I will help you if you have any questions regarding to GPIO > and ACPI. Missed link [1]: https://x-lore.kernel.org/linux-acpi/YRUskkALrPLa2cSf@smile.fi.intel.com/T/#u > Andy Shevchenko (6): > gpio: mlxbf2: Convert to device PM ops > gpio: mlxbf2: Drop wrong use of ACPI_PTR() > gpio: mlxbf2: Use devm_platform_ioremap_resource() > gpio: mlxbf2: Use DEFINE_RES_MEM_NAMED() helper macro > TODO: gpio: mlxbf2: Introduce IRQ support > TODO: net: mellanox: mlxbf_gige: Replace non-standard interrupt > handling > > drivers/gpio/gpio-mlxbf2.c | 151 ++++++++++--- > .../mellanox/mlxbf_gige/mlxbf_gige_gpio.c | 212 ------------------ > 2 files changed, 120 insertions(+), 243 deletions(-) > delete mode 100644 drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_gpio.c > > -- > 2.30.2 >
Acked-by: Asmaa Mnebhi <asmaa@nvidia.com> -----Original Message----- From: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Sent: Monday, August 16, 2021 8:00 AM To: Andy Shevchenko <andriy.shevchenko@linux.intel.com>; David Thompson <davthompson@nvidia.com>; linux-kernel@vger.kernel.org; linux-gpio@vger.kernel.org; netdev@vger.kernel.org; linux-acpi@vger.kernel.org Cc: Linus Walleij <linus.walleij@linaro.org>; Bartosz Golaszewski <bgolaszewski@baylibre.com>; David S. Miller <davem@davemloft.net>; Jakub Kicinski <kuba@kernel.org>; Rafael J. Wysocki <rjw@rjwysocki.net>; Asmaa Mnebhi <asmaa@nvidia.com>; Liming Sun <limings@nvidia.com> Subject: [PATCH v1 1/6] gpio: mlxbf2: Convert to device PM ops Importance: High Convert driver to use modern device PM ops interface. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> --- drivers/gpio/gpio-mlxbf2.c | 21 ++++++--------------- 1 file changed, 6 insertions(+), 15 deletions(-) diff --git a/drivers/gpio/gpio-mlxbf2.c b/drivers/gpio/gpio-mlxbf2.c index befa5e109943..68c471c10fa4 100644 --- a/drivers/gpio/gpio-mlxbf2.c +++ b/drivers/gpio/gpio-mlxbf2.c @@ -47,12 +47,10 @@ #define YU_GPIO_MODE0_SET 0x54 #define YU_GPIO_MODE0_CLEAR 0x58 -#ifdef CONFIG_PM struct mlxbf2_gpio_context_save_regs { u32 gpio_mode0; u32 gpio_mode1; }; -#endif /* BlueField-2 gpio block context structure. */ struct mlxbf2_gpio_context { @@ -61,9 +59,7 @@ struct mlxbf2_gpio_context { /* YU GPIO blocks address */ void __iomem *gpio_io; -#ifdef CONFIG_PM struct mlxbf2_gpio_context_save_regs *csave_regs; -#endif }; /* BlueField-2 gpio shared structure. */ @@ -284,11 +280,9 @@ mlxbf2_gpio_probe(struct platform_device *pdev) return 0; } -#ifdef CONFIG_PM -static int mlxbf2_gpio_suspend(struct platform_device *pdev, - pm_message_t state) +static int __maybe_unused mlxbf2_gpio_suspend(struct device *dev) { - struct mlxbf2_gpio_context *gs = platform_get_drvdata(pdev); + struct mlxbf2_gpio_context *gs = dev_get_drvdata(dev); gs->csave_regs->gpio_mode0 = readl(gs->gpio_io + YU_GPIO_MODE0); @@ -298,9 +292,9 @@ static int mlxbf2_gpio_suspend(struct platform_device *pdev, return 0; } -static int mlxbf2_gpio_resume(struct platform_device *pdev) +static int __maybe_unused mlxbf2_gpio_resume(struct device *dev) { - struct mlxbf2_gpio_context *gs = platform_get_drvdata(pdev); + struct mlxbf2_gpio_context *gs = dev_get_drvdata(dev); writel(gs->csave_regs->gpio_mode0, gs->gpio_io + YU_GPIO_MODE0); @@ -309,7 +303,7 @@ static int mlxbf2_gpio_resume(struct platform_device *pdev) return 0; } -#endif +static SIMPLE_DEV_PM_OPS(mlxbf2_pm_ops, mlxbf2_gpio_suspend, +mlxbf2_gpio_resume); static const struct acpi_device_id __maybe_unused mlxbf2_gpio_acpi_match[] = { { "MLNXBF22", 0 }, @@ -321,12 +315,9 @@ static struct platform_driver mlxbf2_gpio_driver = { .driver = { .name = "mlxbf2_gpio", .acpi_match_table = ACPI_PTR(mlxbf2_gpio_acpi_match), + .pm = &mlxbf2_pm_ops, }, .probe = mlxbf2_gpio_probe, -#ifdef CONFIG_PM - .suspend = mlxbf2_gpio_suspend, - .resume = mlxbf2_gpio_resume, -#endif }; module_platform_driver(mlxbf2_gpio_driver); -- 2.30.2
Hi Andy, Thanks for your help! Please see my comments/questions below. -----Original Message----- From: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Sent: Monday, August 16, 2021 8:00 AM To: Andy Shevchenko <andriy.shevchenko@linux.intel.com>; David Thompson <davthompson@nvidia.com>; linux-kernel@vger.kernel.org; linux-gpio@vger.kernel.org; netdev@vger.kernel.org; linux-acpi@vger.kernel.org Cc: Linus Walleij <linus.walleij@linaro.org>; Bartosz Golaszewski <bgolaszewski@baylibre.com>; David S. Miller <davem@davemloft.net>; Jakub Kicinski <kuba@kernel.org>; Rafael J. Wysocki <rjw@rjwysocki.net>; Asmaa Mnebhi <asmaa@nvidia.com>; Liming Sun <limings@nvidia.com> Subject: [PATCH v1 5/6] TODO: gpio: mlxbf2: Introduce IRQ support Importance: High TBD Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> --- drivers/gpio/gpio-mlxbf2.c | 106 +++++++++++++++++++++++++++++++++++++ 1 file changed, 106 insertions(+) diff --git a/drivers/gpio/gpio-mlxbf2.c b/drivers/gpio/gpio-mlxbf2.c index 3ed95e958c17..bd4c29120b62 100644 --- a/drivers/gpio/gpio-mlxbf2.c +++ b/drivers/gpio/gpio-mlxbf2.c @@ -43,9 +43,13 @@ #define YU_GPIO_MODE0 0x0c #define YU_GPIO_DATASET 0x14 #define YU_GPIO_DATACLEAR 0x18 +#define YU_GPIO_CAUSE_FALL_EN 0x48 #define YU_GPIO_MODE1_CLEAR 0x50 #define YU_GPIO_MODE0_SET 0x54 #define YU_GPIO_MODE0_CLEAR 0x58 +#define YU_GPIO_CAUSE_OR_CAUSE_EVTEN0 0x80 +#define YU_GPIO_CAUSE_OR_EVTEN0 0x94 +#define YU_GPIO_CAUSE_OR_CLRCAUSE 0x98 struct mlxbf2_gpio_context_save_regs { u32 gpio_mode0; @@ -218,6 +222,108 @@ static int mlxbf2_gpio_direction_output(struct gpio_chip *chip, return ret; } +static void mlxbf2_gpio_irq_enable(struct mlxbf2_gpio_context *gs, int +offset) { + unsigned long flags; + u32 val; + + spin_lock_irqsave(&gs->gc.bgpio_lock, flags); + val = readl(gs->gpio_io + YU_GPIO_CAUSE_OR_CLRCAUSE); + val |= BIT(offset); + writel(val, gs->gpio_io + YU_GPIO_CAUSE_OR_CLRCAUSE); + + /* The INT_N interrupt level is active low. + * So enable cause fall bit to detect when GPIO + * state goes low. + */ + val = readl(gs->gpio_io + YU_GPIO_CAUSE_FALL_EN); + val |= BIT(offset); + writel(val, gs->gpio_io + YU_GPIO_CAUSE_FALL_EN); + + /* Enable PHY interrupt by setting the priority level */ + val = readl(gs->gpio_io + YU_GPIO_CAUSE_OR_EVTEN0); + val |= BIT(offset); + writel(val, gs->gpio_io + YU_GPIO_CAUSE_OR_EVTEN0); + spin_unlock_irqrestore(&gs->gc.bgpio_lock, flags); } + +static void mlxbf2_gpio_irq_disable(struct mlxbf2_gpio_context *gs, int +offset) { + unsigned long flags; + u32 val; + + spin_lock_irqsave(&gs->gc.bgpio_lock, flags); + val = readl(gs->gpio_io + YU_GPIO_CAUSE_OR_EVTEN0); + val &= ~BIT(offset); + writel(val, gs->gpio_io + YU_GPIO_CAUSE_OR_EVTEN0); + spin_unlock_irqrestore(&gs->gc.bgpio_lock, flags); } + +static void mlxbf2_gpio_irq_ack(struct mlxbf2_gpio_context *gs, int +offset) { + unsigned long flags; + u32 val; + + spin_lock_irqsave(&gs->gc.bgpio_lock, flags); + val = readl(gs->gpio_io + YU_GPIO_CAUSE_OR_CLRCAUSE); + val |= BIT(offset); + writel(val, gs->gpio_io + YU_GPIO_CAUSE_OR_CLRCAUSE); + spin_unlock_irqrestore(&gs->gc.bgpio_lock, flags); } + +static irqreturn_t mlxbf2_gpio_irq_handler(int irq, void *ptr) { So how do you suggest registering this handler? 1) should I still use BF_RSH0_DEVICE_YU_INT shared interrupt signal? 2) or does Linux kernel know (based on parsing GpioInt) how trigger the handler based on the GPIO datain changing (active low/high)? In this case, the kernel will call this handler whenever the GPIO pin (9 or 12) value changes. I need to check whether GPIO is active low/high but lets assume for now it is open drain active low. We will use acpi_dev_gpio_irq_get to translate GpioInt to a Linux IRQ number: irq = acpi_dev_gpio_irq_get_by(ACPI_COMPANION(dev), " phy-gpios ", 0); ret = devm_request_irq(dev, irq, mlxbf2_gpio_irq_handler, IRQF_ONESHOT | IRQF_SHARED, dev_name(dev), gs); And I will need to add GpioInt to the GPI0 ACPI table as follows: // GPIO Controller Device(GPI0) { Name(_HID, "MLNXBF22") Name(_UID, Zero) Name(_CCA, 1) Name(_CRS, ResourceTemplate() { // for gpio[0] yu block Memory32Fixed(ReadWrite, 0x0280c000, 0x00000100) GpioInt (Level, ActiveLow, Exclusive, PullDefault, , " \\_SB.GPI0") {9} }) Name(_DSD, Package() { ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"), Package() { Package () { "phy-gpios", Package() {^GPI0, 0, 0, 0 }}, Package () { "rst-pin", 32 }, // GPIO pin triggering soft reset on BlueSphere and PRIS } }) } + struct mlxbf2_gpio_context *gs = ptr; + struct gpio_chip *gc = &gs->gc; + unsigned long pending; + u32 level; + + pending = readl(gs->gpio_io + YU_GPIO_CAUSE_OR_CAUSE_EVTEN0); + for_each_set_bit(level, &pending, gc->ngpio) { + int nested_irq = irq_find_mapping(gc->irq.domain, level); + + handle_nested_irq(nested_irq); Now how can the mlxbf_gige_main.c driver also retrieve this nested_irq to register its interrupt handler as well? This irq.domain is only visible to the gpio-mlxbf2.c driver isn't it? phydev->irq (below) should be populated with nested_irq at init time because it is used to register the phy interrupt in this generic function: void phy_request_interrupt(struct phy_device *phydev) { int err; err = request_threaded_irq(phydev->irq, NULL, phy_interrupt, IRQF_ONESHOT | IRQF_SHARED, phydev_name(phydev), phydev); if (err) { phydev_warn(phydev, "Error %d requesting IRQ %d, falling back to polling\n", err, phydev->irq); phydev->irq = PHY_POLL; } else { if (phy_enable_interrupts(phydev)) { phydev_warn(phydev, "Can't enable interrupt, falling back to polling\n"); phy_free_interrupt(phydev); phydev->irq = PHY_POLL; } } } EXPORT_SYMBOL(phy_request_interrupt); + } + + return IRQ_RETVAL(pending); +} + +static void mlxbf2_gpio_irq_mask(struct irq_data *irqd) { + struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd); + struct mlxbf2_gpio_context *gs = gpiochip_get_data(gc); + int offset = irqd_to_hwirq(irqd) % MLXBF2_GPIO_MAX_PINS_PER_BLOCK; Why is the modulo needed? Isn't the hwirq returned a number between 0 and MLXBF2_GPIO_MAX_PINS_PER_BLOCK-1 ? + + mlxbf2_gpio_irq_disable(gs, offset); +} + +static void mlxbf2_gpio_irq_unmask(struct irq_data *irqd) { + struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd); + struct mlxbf2_gpio_context *gs = gpiochip_get_data(gc); + int offset = irqd_to_hwirq(irqd) % MLXBF2_GPIO_MAX_PINS_PER_BLOCK; + + mlxbf2_gpio_irq_enable(gs, offset); +} + +static void mlxbf2_gpio_irq_bus_lock(struct irq_data *irqd) { + mutex_lock(yu_arm_gpio_lock_param.lock); +} + +static void mlxbf2_gpio_irq_bus_sync_unlock(struct irq_data *irqd) { + mutex_unlock(yu_arm_gpio_lock_param.lock); +} + +static struct irq_chip mlxbf2_gpio_irq_chip = { + .name = "mlxbf2_gpio", + .irq_mask = mlxbf2_gpio_irq_mask, + .irq_unmask = mlxbf2_gpio_irq_unmask, + .irq_bus_lock = mlxbf2_gpio_irq_bus_lock, + .irq_bus_sync_unlock = mlxbf2_gpio_irq_bus_sync_unlock, +}; + We also need to make sure that the gpio driver is loaded before the mlxbf-gige driver. Otherwise, the mlxbf-gige 1G interface fails to come up. I have implemented this dependency on the gpio driver before, something like this at the end of the mlxbf-gige driver: MODULE_SOFTDEP("pre: gpio_mlxbf2"); /* BlueField-2 GPIO driver initialization routine. */ static int mlxbf2_gpio_probe(struct platform_device *pdev) -- 2.30.2
On Mon, Aug 16, 2021 at 09:34:50PM +0000, Asmaa Mnebhi wrote: > From: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > Sent: Monday, August 16, 2021 8:00 AM ... > +static irqreturn_t mlxbf2_gpio_irq_handler(int irq, void *ptr) { > > So how do you suggest registering this handler? As usual. This handler should be probably registered via standard mechanisms. Perhaps it's hierarchical IRQ, then use that facility of GPIO library. (see gpio-dwapb.c for the example). > 1) should I still use BF_RSH0_DEVICE_YU_INT shared interrupt signal? I don't know your hardware connection between GPIO and GIC. You have to look into TRM and see how they are connected and what should be programmed for the mode you want to run this in. > 2) or does Linux kernel know (based on parsing GpioInt) how trigger the > handler based on the GPIO datain changing (active low/high)? In this case, > the kernel will call this handler whenever the GPIO pin (9 or 12) value > changes. After driver in place kernel will know how to map, register and handle the GPIO interrupt. But the GIC part is out of the picture here. It may be you will need additional stuff there, like disabling (or else) the interrupts, or providing a bypass. I can't answer to this. > I need to check whether GPIO is active low/high but lets assume for > now it is open drain active low. We will use acpi_dev_gpio_irq_get to > translate GpioInt to a Linux IRQ number: > irq = acpi_dev_gpio_irq_get_by(ACPI_COMPANION(dev), "phy-gpios", 0); > ret = devm_request_irq(dev, irq, mlxbf2_gpio_irq_handler, IRQF_ONESHOT | IRQF_SHARED, dev_name(dev), gs); Yes. (I dunno about one short and shared flags, but you should know it better than me) > And I will need to add GpioInt to the GPI0 ACPI table as follows: But you told me that it's already on the market, how are you suppose to change existing tables? > // GPIO Controller > Device(GPI0) { > Name(_HID, "MLNXBF22") > Name(_UID, Zero) > Name(_CCA, 1) > Name(_CRS, ResourceTemplate() { > // for gpio[0] yu block > Memory32Fixed(ReadWrite, 0x0280c000, 0x00000100) > GpioInt (Level, ActiveLow, Exclusive, PullDefault, , " \\_SB.GPI0") {9} > }) > Name(_DSD, Package() { > ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"), > Package() { > Package () { "phy-gpios", Package() {^GPI0, 0, 0, 0 }}, > Package () { "rst-pin", 32 }, // GPIO pin triggering soft reset on BlueSphere and PRIS > } > }) > } No, it's completely wrong. The resources are provided by GPIO controller and consumed by devices. You showed me the table for the consumer, which is good (of course if you wish to use Edge triggered interrupts there). ... > + handle_nested_irq(nested_irq); > Now how can the mlxbf_gige_main.c driver also retrieve this nested_irq to > register its interrupt handler as well? This irq.domain is only visible to > the gpio-mlxbf2.c driver isn't it? phydev->irq (below) should be populated > with nested_irq at init time because it is used to register the phy interrupt > in this generic function: nested here is an example, you have to check which one to use. Moreover the code misses ->irq_set_type() callback. So, yes, domain will be GPIOs but IRQ core will handle it properly. > void phy_request_interrupt(struct phy_device *phydev) > { > int err; > > err = request_threaded_irq(phydev->irq, NULL, phy_interrupt, > IRQF_ONESHOT | IRQF_SHARED, > phydev_name(phydev), phydev); You have several IRQ resources (Interrupt() and GpioInt() ones) in the consumer device node. I don't know how your hardware is designed, but if you want to use GPIO, then this phydev->irq should be a Linux vIRQ returned from above mentioned acpi_dev_gpio_irq_get_by() call. Everything else is magically happens. ... > + int offset = irqd_to_hwirq(irqd) % MLXBF2_GPIO_MAX_PINS_PER_BLOCK; > Why is the modulo needed? Isn't the hwirq returned a number between 0 and > MLXBF2_GPIO_MAX_PINS_PER_BLOCK-1 ? It's copy'n'paste from somewhere, since you have device per bank you don't need it. ... > We also need to make sure that the gpio driver is loaded before the > mlxbf-gige driver. Otherwise, the mlxbf-gige 1G interface fails to come up. > I have implemented this dependency on the gpio driver before, something like > this at the end of the mlxbf-gige driver: > MODULE_SOFTDEP("pre: gpio_mlxbf2"); No, when you have GPIO device is listed in the tables the IRQ mapping will return you deferred probe. It doesn't matter when device will appear, but it will be functional only when all resource requirements are satisfied. Above soft dependency doesn't guarantee this, deferred probe does.
Hi Asmaa > > And I will need to add GpioInt to the GPI0 ACPI table as follows: > > But you told me that it's already on the market, how are you suppose to change > existing tables? BIOSes have as many bugs a the kernel. So your product should be designed so you can upgrade the kernel and upgrade the BIOS. phylib itself does not care if there is an interrupt or not. It will fall back to polling. So if your driver finds itself running with old tables, it does not matter. Just print a warning to the kernel logs suggesting the user upgrades their BIOS firmware. > > // GPIO Controller > > Device(GPI0) { > > Name(_HID, "MLNXBF22") > > Name(_UID, Zero) > > Name(_CCA, 1) > > Name(_CRS, ResourceTemplate() { > > // for gpio[0] yu block > > Memory32Fixed(ReadWrite, 0x0280c000, 0x00000100) > > GpioInt (Level, ActiveLow, Exclusive, PullDefault, , " \\_SB.GPI0") {9} > > }) > > Name(_DSD, Package() { > > ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"), > > Package() { > > Package () { "phy-gpios", Package() {^GPI0, 0, 0, 0 }}, > > Package () { "rst-pin", 32 }, // GPIO pin triggering soft reset on BlueSphere and PRIS > > } > > }) > > } > > No, it's completely wrong. The resources are provided by GPIO controller and > consumed by devices. In the device tree world, you list the interrupt in the PHY node. Documentation/devicetree/bindings/net/ethernet-phy.yaml gives an example: ethernet { #address-cells = <1>; #size-cells = <0>; ethernet-phy@0 { compatible = "ethernet-phy-id0141.0e90", "ethernet-phy-ieee802.3-c45"; interrupt-parent = <&PIC>; interrupts = <35 1>; reg = <0>; resets = <&rst 8>; reset-names = "phy"; reset-gpios = <&gpio1 4 1>; reset-assert-us = <1000>; reset-deassert-us = <2000>; }; }; You need to do something similar in the ACPI world. There was a very long discussion in this area recently, and some patches merged. You probably need to build on that. See: firmware-guide/acpi/dsd/phy.rst Andrew
Thank you Andrew and Andy! I will prepare 2 patches (one for gpio-mlxbf2.c and one for mlxbf-gige) and send it your way. -----Original Message----- From: Andrew Lunn <andrew@lunn.ch> Sent: Wednesday, August 18, 2021 6:40 PM To: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Asmaa Mnebhi <asmaa@nvidia.com>; David Thompson <davthompson@nvidia.com>; linux-kernel@vger.kernel.org; linux-gpio@vger.kernel.org; netdev@vger.kernel.org; linux-acpi@vger.kernel.org; Linus Walleij <linus.walleij@linaro.org>; Bartosz Golaszewski <bgolaszewski@baylibre.com>; David S. Miller <davem@davemloft.net>; Jakub Kicinski <kuba@kernel.org>; Rafael J. Wysocki <rjw@rjwysocki.net>; Liming Sun <limings@nvidia.com> Subject: Re: [PATCH v1 5/6] TODO: gpio: mlxbf2: Introduce IRQ support Importance: High Hi Asmaa > > And I will need to add GpioInt to the GPI0 ACPI table as follows: > > But you told me that it's already on the market, how are you suppose > to change existing tables? BIOSes have as many bugs a the kernel. So your product should be designed so you can upgrade the kernel and upgrade the BIOS. phylib itself does not care if there is an interrupt or not. It will fall back to polling. So if your driver finds itself running with old tables, it does not matter. Just print a warning to the kernel logs suggesting the user upgrades their BIOS firmware. > > // GPIO Controller > > Device(GPI0) { > > Name(_HID, "MLNXBF22") > > Name(_UID, Zero) > > Name(_CCA, 1) > > Name(_CRS, ResourceTemplate() { > > // for gpio[0] yu block > > Memory32Fixed(ReadWrite, 0x0280c000, 0x00000100) > > GpioInt (Level, ActiveLow, Exclusive, PullDefault, , " \\_SB.GPI0") {9} > > }) > > Name(_DSD, Package() { > > ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"), > > Package() { > > Package () { "phy-gpios", Package() {^GPI0, 0, 0, 0 }}, > > Package () { "rst-pin", 32 }, // GPIO pin triggering soft reset on BlueSphere and PRIS > > } > > }) > > } > > No, it's completely wrong. The resources are provided by GPIO > controller and consumed by devices. In the device tree world, you list the interrupt in the PHY node. Documentation/devicetree/bindings/net/ethernet-phy.yaml gives an example: ethernet { #address-cells = <1>; #size-cells = <0>; ethernet-phy@0 { compatible = "ethernet-phy-id0141.0e90", "ethernet-phy-ieee802.3-c45"; interrupt-parent = <&PIC>; interrupts = <35 1>; reg = <0>; resets = <&rst 8>; reset-names = "phy"; reset-gpios = <&gpio1 4 1>; reset-assert-us = <1000>; reset-deassert-us = <2000>; }; }; You need to do something similar in the ACPI world. There was a very long discussion in this area recently, and some patches merged. You probably need to build on that. See: firmware-guide/acpi/dsd/phy.rst Andrew
Hi Andy, Hi Andrew,
I have a question regarding patch submission. I am going to mimic what Andy has done for v5/6 and v6/6 and send 2 patches in a bundle as follows:
/* for the cover letter */ : Subject: [PATCH v1 0/2] gpio: mlxbf2: Introduce proper interrupt handling
Subject: [PATCH v1 1/2] gpio: mlxbf2: Introduce IRQ support
Subject: [PATCH v1 2/2] net: mellanox: mlxbf_gige: Replace non-standard interrupt handling
Questions:
1) do the subject lines look ok? i.e. sending patches that target "net" as opposed to "net-next"
2) would you like me to add a "Fixes" tag to each patch as follows? I am not sure if you consider this a bug?
Fixes: f92e1869d74e ("Add Mellanox BlueField Gigabit Ethernet driver")
Thank you.
Asmaa
-----Original Message-----
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Sent: Wednesday, August 18, 2021 10:08 AM
To: Asmaa Mnebhi <asmaa@nvidia.com>
Cc: David Thompson <davthompson@nvidia.com>; linux-kernel@vger.kernel.org; linux-gpio@vger.kernel.org; netdev@vger.kernel.org; linux-acpi@vger.kernel.org; Linus Walleij <linus.walleij@linaro.org>; Bartosz Golaszewski <bgolaszewski@baylibre.com>; David S. Miller <davem@davemloft.net>; Jakub Kicinski <kuba@kernel.org>; Rafael J. Wysocki <rjw@rjwysocki.net>; Liming Sun <limings@nvidia.com>
Subject: Re: [PATCH v1 5/6] TODO: gpio: mlxbf2: Introduce IRQ support
Importance: High
On Mon, Aug 16, 2021 at 09:34:50PM +0000, Asmaa Mnebhi wrote:
> From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Sent: Monday, August 16, 2021 8:00 AM
...
> +static irqreturn_t mlxbf2_gpio_irq_handler(int irq, void *ptr) {
>
> So how do you suggest registering this handler?
As usual. This handler should be probably registered via standard mechanisms.
Perhaps it's hierarchical IRQ, then use that facility of GPIO library.
(see gpio-dwapb.c for the example).
> 1) should I still use BF_RSH0_DEVICE_YU_INT shared interrupt signal?
I don't know your hardware connection between GPIO and GIC. You have to look into TRM and see how they are connected and what should be programmed for the mode you want to run this in.
> 2) or does Linux kernel know (based on parsing GpioInt) how trigger
> the handler based on the GPIO datain changing (active low/high)? In
> this case, the kernel will call this handler whenever the GPIO pin (9
> or 12) value changes.
After driver in place kernel will know how to map, register and handle the GPIO interrupt. But the GIC part is out of the picture here. It may be you will need additional stuff there, like disabling (or else) the interrupts, or providing a bypass. I can't answer to this.
> I need to check whether GPIO is active low/high but lets assume for
> now it is open drain active low. We will use acpi_dev_gpio_irq_get to
> translate GpioInt to a Linux IRQ number:
> irq = acpi_dev_gpio_irq_get_by(ACPI_COMPANION(dev), "phy-gpios", 0);
> ret = devm_request_irq(dev, irq, mlxbf2_gpio_irq_handler, IRQF_ONESHOT
> | IRQF_SHARED, dev_name(dev), gs);
Yes.
(I dunno about one short and shared flags, but you should know it better than me)
> And I will need to add GpioInt to the GPI0 ACPI table as follows:
But you told me that it's already on the market, how are you suppose to change existing tables?
> // GPIO Controller
> Device(GPI0) {
> Name(_HID, "MLNXBF22")
> Name(_UID, Zero)
> Name(_CCA, 1)
> Name(_CRS, ResourceTemplate() {
> // for gpio[0] yu block
> Memory32Fixed(ReadWrite, 0x0280c000, 0x00000100)
> GpioInt (Level, ActiveLow, Exclusive, PullDefault, , " \\_SB.GPI0") {9}
> })
> Name(_DSD, Package() {
> ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
> Package() {
> Package () { "phy-gpios", Package() {^GPI0, 0, 0, 0 }},
> Package () { "rst-pin", 32 }, // GPIO pin triggering soft reset on BlueSphere and PRIS
> }
> })
> }
No, it's completely wrong. The resources are provided by GPIO controller and consumed by devices. You showed me the table for the consumer, which is good (of course if you wish to use Edge triggered interrupts there).
...
> + handle_nested_irq(nested_irq);
> Now how can the mlxbf_gige_main.c driver also retrieve this nested_irq
> to register its interrupt handler as well? This irq.domain is only
> visible to the gpio-mlxbf2.c driver isn't it? phydev->irq (below)
> should be populated with nested_irq at init time because it is used to
> register the phy interrupt in this generic function:
nested here is an example, you have to check which one to use.
Moreover the code misses ->irq_set_type() callback.
So, yes, domain will be GPIOs but IRQ core will handle it properly.
> void phy_request_interrupt(struct phy_device *phydev) {
> int err;
>
> err = request_threaded_irq(phydev->irq, NULL, phy_interrupt,
> IRQF_ONESHOT | IRQF_SHARED,
> phydev_name(phydev), phydev);
You have several IRQ resources (Interrupt() and GpioInt() ones) in the consumer device node. I don't know how your hardware is designed, but if you want to use GPIO, then this phydev->irq should be a Linux vIRQ returned from above mentioned acpi_dev_gpio_irq_get_by() call. Everything else is magically happens.
...
> + int offset = irqd_to_hwirq(irqd) % MLXBF2_GPIO_MAX_PINS_PER_BLOCK;
> Why is the modulo needed? Isn't the hwirq returned a number between 0
> and
> MLXBF2_GPIO_MAX_PINS_PER_BLOCK-1 ?
It's copy'n'paste from somewhere, since you have device per bank you don't need it.
...
> We also need to make sure that the gpio driver is loaded before the
> mlxbf-gige driver. Otherwise, the mlxbf-gige 1G interface fails to come up.
> I have implemented this dependency on the gpio driver before,
> something like this at the end of the mlxbf-gige driver:
> MODULE_SOFTDEP("pre: gpio_mlxbf2");
No, when you have GPIO device is listed in the tables the IRQ mapping will return you deferred probe. It doesn't matter when device will appear, but it will be functional only when all resource requirements are satisfied.
Above soft dependency doesn't guarantee this, deferred probe does.
--
With Best Regards,
Andy Shevchenko
This is just a WIP / TODO series based on the discussion [1]. I hope nVidia will finish it and fix the initial problem sooner than later. Bart, Linus, First 4 patches may be directly applied to the tree (they are at least compile-tested, but I believe they won't change any functionality. Patch 5 is some stubs that should have been done in the driver. Patch 6 is follow up removal of custom GPIO IRQ handling from Mellanox GBE driver. Both of them are quite far from finishing, but it's a start for nVidia to develop and test proper solution. In any case, I will probably sent end this week the ACPI IRQ abuse part from the GBE driver (I won't touch OF path). ARs for nVidia: 0) review this series; 1) properly develop GPIO driver; 2) replace custom code with correct one; 3) send the work for review to GPIO and ACPI maintainers (basically list of this series). On my side I will help you if you have any questions regarding to GPIO and ACPI. Andy Shevchenko (6): gpio: mlxbf2: Convert to device PM ops gpio: mlxbf2: Drop wrong use of ACPI_PTR() gpio: mlxbf2: Use devm_platform_ioremap_resource() gpio: mlxbf2: Use DEFINE_RES_MEM_NAMED() helper macro TODO: gpio: mlxbf2: Introduce IRQ support TODO: net: mellanox: mlxbf_gige: Replace non-standard interrupt handling drivers/gpio/gpio-mlxbf2.c | 151 ++++++++++--- .../mellanox/mlxbf_gige/mlxbf_gige_gpio.c | 212 ------------------ 2 files changed, 120 insertions(+), 243 deletions(-) delete mode 100644 drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_gpio.c