From 0ea683931adb27d588fa74c30ac242ed2414e438 Mon Sep 17 00:00:00 2001 From: Serge Semin Date: Thu, 30 Jul 2020 18:28:02 +0300 Subject: [PATCH] gpio: dwapb: Convert driver to using the GPIO-lib-based IRQ-chip GPIO-lib provides a ready-to-use interface to initialize an IRQ-chip on top of a GPIO chip. It's better from maintainability and readability point of view to use one instead of supporting a hand-written Generic IRQ-chip-based implementation. Moreover the new implementation won't cause much functional overhead but will provide a cleaner driver code. All of that makes the DW APB GPIO driver conversion pretty much justified especially seeing a tendency of the other GPIO drivers getting converted too. Here is what we do in the framework of this commit to convert the driver to using the GPIO-lib-based IRQ-chip interface: 1) IRQ ack, mask and unmask callbacks are locally defined instead of using the Generic IRQ-chip ones. 2) An irq_chip structure instance is embedded into the dwapb_gpio private data. Note we can't have a static instance of that structure since GPIO-lib will add some hooks into it by calling gpiochip_set_irq_hooks(). A warning about that would have been printed by the GPIO-lib code if we used a single irq_chip structure instance for multiple DW APB GPIO controllers. 3) Initialize the gpio_irq_chip structure embedded into the gpio_chip descriptor. By default there is no IRQ enabled so any event raised will be handled by the handle_bad_irq() IRQ flow handler. If DW APB GPIO IP-core is synthesized to have non-shared reference IRQ-lines, then as before the hierarchical and cascaded cases are distinguished by checking how many parental IRQs are defined. (Note irq_set_chained_handler_and_data() won't initialize IRQs, which descriptors couldn't be found.) If DW APB GPIO IP is used on a platform with shared IRQ line, then we simply won't let the GPIO-lib to initialize the parental IRQs, but will handle them locally in the driver. 4) Discard linear IRQ-domain and Generic IRQ-chip initialization, since GPIO-lib IRQ-chip interface will create a new domain and accept a standard IRQ-chip structure pointer based on the setting we provided in the gpio_irq_chip structure. 5) Manually select a proper IRQ flow handler directly in the irq_set_type() callback by calling irq_set_handler_locked() method, since an ordinary (not Generic) irq_chip descriptor is now utilized. Note this shalln't give any regression 6) Alter CONFIG_GPIO_DWAPB kernel config to select CONFIG_GPIOLIB_IRQCHIP instead of CONFIG_GENERIC_IRQ_CHIP. Note neither 4) nor 5) shall cause a regression of commit 6a2f4b7dadd5 ("gpio: dwapb: use a second irq chip"), since the later isn't properly used here anyway. Signed-off-by: Serge Semin Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/20200730152808.2955-6-Sergey.Semin@baikalelectronics.ru Signed-off-by: Linus Walleij --- drivers/gpio/Kconfig | 2 +- drivers/gpio/gpio-dwapb.c | 203 +++++++++++++++++++++++++--------------------- 2 files changed, 111 insertions(+), 94 deletions(-) diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index 8030fd9..5cfdaf3 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -202,7 +202,7 @@ config GPIO_DAVINCI config GPIO_DWAPB tristate "Synopsys DesignWare APB GPIO driver" select GPIO_GENERIC - select GENERIC_IRQ_CHIP + select GPIOLIB_IRQCHIP help Say Y or M here to build support for the Synopsys DesignWare APB GPIO block. diff --git a/drivers/gpio/gpio-dwapb.c b/drivers/gpio/gpio-dwapb.c index f340011..eb3a6da 100644 --- a/drivers/gpio/gpio-dwapb.c +++ b/drivers/gpio/gpio-dwapb.c @@ -13,7 +13,6 @@ #include #include #include -#include #include #include #include @@ -83,8 +82,15 @@ struct dwapb_context { }; #endif +struct dwapb_gpio_port_irqchip { + struct irq_chip irqchip; + unsigned int nr_irqs; + unsigned int irq[DWAPB_MAX_GPIOS]; +}; + struct dwapb_gpio_port { struct gpio_chip gc; + struct dwapb_gpio_port_irqchip *pirq; bool is_registered; struct dwapb_gpio *gpio; #ifdef CONFIG_PM_SLEEP @@ -92,13 +98,14 @@ struct dwapb_gpio_port { #endif unsigned int idx; }; +#define to_dwapb_gpio(_gc) \ + (container_of(_gc, struct dwapb_gpio_port, gc)->gpio) struct dwapb_gpio { struct device *dev; void __iomem *regs; struct dwapb_gpio_port *ports; unsigned int nr_ports; - struct irq_domain *domain; unsigned int flags; struct reset_control *rst; struct clk_bulk_data clks[DWAPB_NR_CLOCKS]; @@ -193,12 +200,13 @@ static void dwapb_toggle_trigger(struct dwapb_gpio *gpio, unsigned int offs) static u32 dwapb_do_irq(struct dwapb_gpio *gpio) { + struct gpio_chip *gc = &gpio->ports[0].gc; unsigned long irq_status; irq_hw_number_t hwirq; irq_status = dwapb_read(gpio, GPIO_INTSTATUS); for_each_set_bit(hwirq, &irq_status, DWAPB_MAX_GPIOS) { - int gpio_irq = irq_find_mapping(gpio->domain, hwirq); + int gpio_irq = irq_find_mapping(gc->irq.domain, hwirq); u32 irq_type = irq_get_trigger_type(gpio_irq); generic_handle_irq(gpio_irq); @@ -225,11 +233,48 @@ static irqreturn_t dwapb_irq_handler_mfd(int irq, void *dev_id) return IRQ_RETVAL(dwapb_do_irq(dev_id)); } +static void dwapb_irq_ack(struct irq_data *d) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct dwapb_gpio *gpio = to_dwapb_gpio(gc); + u32 val = BIT(irqd_to_hwirq(d)); + unsigned long flags; + + spin_lock_irqsave(&gc->bgpio_lock, flags); + dwapb_write(gpio, GPIO_PORTA_EOI, val); + spin_unlock_irqrestore(&gc->bgpio_lock, flags); +} + +static void dwapb_irq_mask(struct irq_data *d) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct dwapb_gpio *gpio = to_dwapb_gpio(gc); + unsigned long flags; + u32 val; + + spin_lock_irqsave(&gc->bgpio_lock, flags); + val = dwapb_read(gpio, GPIO_INTMASK) | BIT(irqd_to_hwirq(d)); + dwapb_write(gpio, GPIO_INTMASK, val); + spin_unlock_irqrestore(&gc->bgpio_lock, flags); +} + +static void dwapb_irq_unmask(struct irq_data *d) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct dwapb_gpio *gpio = to_dwapb_gpio(gc); + unsigned long flags; + u32 val; + + spin_lock_irqsave(&gc->bgpio_lock, flags); + val = dwapb_read(gpio, GPIO_INTMASK) & ~BIT(irqd_to_hwirq(d)); + dwapb_write(gpio, GPIO_INTMASK, val); + spin_unlock_irqrestore(&gc->bgpio_lock, flags); +} + static void dwapb_irq_enable(struct irq_data *d) { - struct irq_chip_generic *igc = irq_data_get_irq_chip_data(d); - struct dwapb_gpio *gpio = igc->private; - struct gpio_chip *gc = &gpio->ports[0].gc; + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct dwapb_gpio *gpio = to_dwapb_gpio(gc); unsigned long flags; u32 val; @@ -242,9 +287,8 @@ static void dwapb_irq_enable(struct irq_data *d) static void dwapb_irq_disable(struct irq_data *d) { - struct irq_chip_generic *igc = irq_data_get_irq_chip_data(d); - struct dwapb_gpio *gpio = igc->private; - struct gpio_chip *gc = &gpio->ports[0].gc; + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct dwapb_gpio *gpio = to_dwapb_gpio(gc); unsigned long flags; u32 val; @@ -257,9 +301,8 @@ static void dwapb_irq_disable(struct irq_data *d) static int dwapb_irq_set_type(struct irq_data *d, u32 type) { - struct irq_chip_generic *igc = irq_data_get_irq_chip_data(d); - struct dwapb_gpio *gpio = igc->private; - struct gpio_chip *gc = &gpio->ports[0].gc; + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct dwapb_gpio *gpio = to_dwapb_gpio(gc); irq_hw_number_t bit = irqd_to_hwirq(d); unsigned long level, polarity, flags; @@ -293,7 +336,10 @@ static int dwapb_irq_set_type(struct irq_data *d, u32 type) break; } - irq_setup_alt_chip(d, type); + if (type & IRQ_TYPE_LEVEL_MASK) + irq_set_handler_locked(d, handle_level_irq); + else if (type & IRQ_TYPE_EDGE_BOTH) + irq_set_handler_locked(d, handle_edge_irq); dwapb_write(gpio, GPIO_INTTYPE_LEVEL, level); if (type != IRQ_TYPE_EDGE_BOTH) @@ -354,79 +400,67 @@ static int dwapb_gpio_set_config(struct gpio_chip *gc, unsigned offset, return dwapb_gpio_set_debounce(gc, offset, debounce); } +static int dwapb_convert_irqs(struct dwapb_gpio_port_irqchip *pirq, + struct dwapb_port_property *pp) +{ + int i; + + /* Group all available IRQs into an array of parental IRQs. */ + for (i = 0; i < pp->ngpio; ++i) { + if (!pp->irq[i]) + continue; + + pirq->irq[pirq->nr_irqs++] = pp->irq[i]; + } + + return pirq->nr_irqs ? 0 : -ENOENT; +} + static void dwapb_configure_irqs(struct dwapb_gpio *gpio, struct dwapb_gpio_port *port, struct dwapb_port_property *pp) { + struct dwapb_gpio_port_irqchip *pirq; struct gpio_chip *gc = &port->gc; - struct fwnode_handle *fwnode = pp->fwnode; - struct irq_chip_generic *irq_gc = NULL; - unsigned int ngpio = gc->ngpio; - struct irq_chip_type *ct; - irq_hw_number_t hwirq; - int err, i; - - if (memchr_inv(pp->irq, 0, sizeof(pp->irq)) == NULL) { - dev_warn(gpio->dev, "no IRQ for port%d\n", pp->idx); - return; - } - - gpio->domain = irq_domain_create_linear(fwnode, ngpio, - &irq_generic_chip_ops, gpio); - if (!gpio->domain) - return; + struct gpio_irq_chip *girq; + int err; - err = irq_alloc_domain_generic_chips(gpio->domain, ngpio, 2, - DWAPB_DRIVER_NAME, handle_bad_irq, - IRQ_NOREQUEST, 0, - IRQ_GC_INIT_NESTED_LOCK); - if (err) { - dev_info(gpio->dev, "irq_alloc_domain_generic_chips failed\n"); - irq_domain_remove(gpio->domain); - gpio->domain = NULL; + pirq = devm_kzalloc(gpio->dev, sizeof(*pirq), GFP_KERNEL); + if (!pirq) return; - } - irq_gc = irq_get_domain_generic_chip(gpio->domain, 0); - if (!irq_gc) { - irq_domain_remove(gpio->domain); - gpio->domain = NULL; - return; + if (dwapb_convert_irqs(pirq, pp)) { + dev_warn(gpio->dev, "no IRQ for port%d\n", pp->idx); + goto err_kfree_pirq; } - irq_gc->reg_base = gpio->regs; - irq_gc->private = gpio; - - for (i = 0; i < 2; i++) { - ct = &irq_gc->chip_types[i]; - ct->chip.irq_ack = irq_gc_ack_set_bit; - ct->chip.irq_mask = irq_gc_mask_set_bit; - ct->chip.irq_unmask = irq_gc_mask_clr_bit; - ct->chip.irq_set_type = dwapb_irq_set_type; - ct->chip.irq_enable = dwapb_irq_enable; - ct->chip.irq_disable = dwapb_irq_disable; + girq = &gc->irq; + girq->handler = handle_bad_irq; + girq->default_type = IRQ_TYPE_NONE; + + port->pirq = pirq; + pirq->irqchip.name = DWAPB_DRIVER_NAME; + pirq->irqchip.irq_ack = dwapb_irq_ack; + pirq->irqchip.irq_mask = dwapb_irq_mask; + pirq->irqchip.irq_unmask = dwapb_irq_unmask; + pirq->irqchip.irq_set_type = dwapb_irq_set_type; + pirq->irqchip.irq_enable = dwapb_irq_enable; + pirq->irqchip.irq_disable = dwapb_irq_disable; #ifdef CONFIG_PM_SLEEP - ct->chip.irq_set_wake = dwapb_irq_set_wake; + pirq->irqchip.irq_set_wake = dwapb_irq_set_wake; #endif - ct->regs.ack = gpio_reg_convert(gpio, GPIO_PORTA_EOI); - ct->regs.mask = gpio_reg_convert(gpio, GPIO_INTMASK); - ct->type = IRQ_TYPE_LEVEL_MASK; - } - - irq_gc->chip_types[0].type = IRQ_TYPE_LEVEL_MASK; - irq_gc->chip_types[0].handler = handle_level_irq; - irq_gc->chip_types[1].type = IRQ_TYPE_EDGE_BOTH; - irq_gc->chip_types[1].handler = handle_edge_irq; if (!pp->irq_shared) { - int i; - - for (i = 0; i < pp->ngpio; i++) { - if (pp->irq[i]) - irq_set_chained_handler_and_data(pp->irq[i], - dwapb_irq_handler, gpio); - } + girq->num_parents = pirq->nr_irqs; + girq->parents = pirq->irq; + girq->parent_handler_data = gpio; + girq->parent_handler = dwapb_irq_handler; } else { + /* This will let us handle the parent IRQ in the driver */ + girq->num_parents = 0; + girq->parents = NULL; + girq->parent_handler = NULL; + /* * Request a shared IRQ since where MFD would have devices * using the same irq pin @@ -436,33 +470,18 @@ static void dwapb_configure_irqs(struct dwapb_gpio *gpio, IRQF_SHARED, DWAPB_DRIVER_NAME, gpio); if (err) { dev_err(gpio->dev, "error requesting IRQ\n"); - irq_domain_remove(gpio->domain); - gpio->domain = NULL; - return; + goto err_kfree_pirq; } } - for (hwirq = 0; hwirq < ngpio; hwirq++) - irq_create_mapping(gpio->domain, hwirq); + girq->chip = &pirq->irqchip; port->gc.to_irq = dwapb_gpio_to_irq; -} - -static void dwapb_irq_teardown(struct dwapb_gpio *gpio) -{ - struct dwapb_gpio_port *port = &gpio->ports[0]; - struct gpio_chip *gc = &port->gc; - unsigned int ngpio = gc->ngpio; - irq_hw_number_t hwirq; - - if (!gpio->domain) - return; - for (hwirq = 0; hwirq < ngpio; hwirq++) - irq_dispose_mapping(irq_find_mapping(gpio->domain, hwirq)); + return; - irq_domain_remove(gpio->domain); - gpio->domain = NULL; +err_kfree_pirq: + devm_kfree(gpio->dev, pirq); } static int dwapb_gpio_add_port(struct dwapb_gpio *gpio, @@ -699,7 +718,6 @@ static int dwapb_gpio_probe(struct platform_device *pdev) out_unregister: dwapb_gpio_unregister(gpio); - dwapb_irq_teardown(gpio); clk_bulk_disable_unprepare(DWAPB_NR_CLOCKS, gpio->clks); return err; @@ -710,7 +728,6 @@ static int dwapb_gpio_remove(struct platform_device *pdev) struct dwapb_gpio *gpio = platform_get_drvdata(pdev); dwapb_gpio_unregister(gpio); - dwapb_irq_teardown(gpio); reset_control_assert(gpio->rst); clk_bulk_disable_unprepare(DWAPB_NR_CLOCKS, gpio->clks); -- 2.7.4