ICP DAS LP-8x4x contains FPGA chip. The chip functions as an interrupt source providing 16 additional interrupts among other things. The interrupt lines are muxed to a GPIO pin of a 2nd level PXA-GPIO interrupt controller. GPIO pins of the 2nd level controller are in turn muxed to a CPU interrupt line. Until pxa is completely converted to device tree, it is impossible to use IRQCHIP_DECLARE() and the irqdomain needs to added manually. Drivers for the on-CPU IRQs and GPIO-IRQs are loaded using postcore_initcall(). We need to have all irq domain drivers loaded prior to DT parsing in order to allow normal initialization of IRQ resources with DT. Signed-off-by: Sergei Ianovich <ynvich@xxxxxxxxx> Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx> CC: Arnd Bergmann <arnd@xxxxxxxx> --- v3.1..v3.2 fixes to apply Linus Walleij's "Reviewed-by": * add kerneldoc comment for state container struct * rename irq -> hwirq for clarity * drop overzealous error checks from the hotpaths v3..v3.1 fixes according to Linus Walleij review comments: * update commit message * use state container instead of global variables * get hardware irq nums from irq_data, don't calculate them * use BIT() macro * add defines for system irq register masks * replace cycle control variable with break * use better names for resource variables * add a linear domain instead of a legacy one * use irq_create_mapping() instead of irq_alloc_desc() v2..v3 * no changes (except number 09/16 -> 11/21) v0..v2 * extract irqchip and move to drivers/irqchip/ * use device tree * use devm helpers where possible .../bindings/interrupt-controller/irq-lp8x4x.txt | 49 +++++ arch/arm/boot/dts/pxa27x-lp8x4x.dts | 10 + drivers/irqchip/Kconfig | 5 + drivers/irqchip/Makefile | 1 + drivers/irqchip/irq-lp8x4x.c | 227 +++++++++++++++++++++ 5 files changed, 292 insertions(+) create mode 100644 Documentation/devicetree/bindings/interrupt-controller/irq-lp8x4x.txt create mode 100644 drivers/irqchip/irq-lp8x4x.c diff --git a/Documentation/devicetree/bindings/interrupt-controller/irq-lp8x4x.txt b/Documentation/devicetree/bindings/interrupt-controller/irq-lp8x4x.txt new file mode 100644 index 0000000..c8940d2 --- /dev/null +++ b/Documentation/devicetree/bindings/interrupt-controller/irq-lp8x4x.txt @@ -0,0 +1,49 @@ +ICP DAS LP-8x4x FPGA Interrupt Controller + +ICP DAS LP-8x4x contains FPGA chip. The chip functions as a interrupt +source providing 16 additional interrupts among other things. + +Required properties: +- compatible : should be "icpdas,irq-lp8x4x" + +- reg: physical base address of the controller and length of memory mapped + region. + +- interrupt-controller : identifies the node as an interrupt controller + +- #interrupt-cells : should be 1 + +- interrupts : should provide interrupt + +- interrupt-parent : should provide a link to interrupt controller either + explicitly and implicitly from a parent node + +Example: + + fpga: fpga@17000006 { + compatible = "icpdas,irq-lp8x4x"; + reg = <0x17000006 0x16>; + interrupt-parent = <&gpio>; + interrupts = <3 IRQ_TYPE_EDGE_RISING>; + #interrupt-cells = <1>; + interrupt-controller; + status = "okay"; + }; + + uart@17009050 { + compatible = "icpdas,uart-lp8x4x"; + reg = <0x17009050 0x10 + 0x17009030 0x02>; + interrupt-parent = <&fpga>; + interrupts = <13>; + status = "okay"; + }; + + uart@17009060 { + compatible = "icpdas,uart-lp8x4x"; + reg = <0x17009060 0x10 + 0x17009032 0x02>; + interrupt-parent = <&fpga>; + interrupts = <14>; + status = "okay"; + }; diff --git a/arch/arm/boot/dts/pxa27x-lp8x4x.dts b/arch/arm/boot/dts/pxa27x-lp8x4x.dts index 07856e0..78dfd2e 100644 --- a/arch/arm/boot/dts/pxa27x-lp8x4x.dts +++ b/arch/arm/boot/dts/pxa27x-lp8x4x.dts @@ -167,6 +167,16 @@ reg = <0xa000 0x1000 0x901e 0x1>; }; + + fpgairq: irq@9006 { + compatible = "icpdas,irq-lp8x4x"; + reg = <0x9006 0x16>; + interrupt-parent = <&gpio>; + interrupts = <3 IRQ_TYPE_EDGE_FALLING>; + #interrupt-cells = <1>; + interrupt-controller; + status = "okay"; + }; }; }; }; diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig index 3792a1a..7e22729 100644 --- a/drivers/irqchip/Kconfig +++ b/drivers/irqchip/Kconfig @@ -35,6 +35,11 @@ config IMGPDC_IRQ select GENERIC_IRQ_CHIP select IRQ_DOMAIN +config LP8X4X_IRQ + bool + depends on OF + select IRQ_DOMAIN + config ORION_IRQCHIP bool select IRQ_DOMAIN diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile index c60b901..8a28927 100644 --- a/drivers/irqchip/Makefile +++ b/drivers/irqchip/Makefile @@ -22,3 +22,4 @@ obj-$(CONFIG_RENESAS_IRQC) += irq-renesas-irqc.o obj-$(CONFIG_VERSATILE_FPGA_IRQ) += irq-versatile-fpga.o obj-$(CONFIG_ARCH_VT8500) += irq-vt8500.o obj-$(CONFIG_TB10X_IRQC) += irq-tb10x.o +obj-$(CONFIG_LP8X4X_IRQ) += irq-lp8x4x.o diff --git a/drivers/irqchip/irq-lp8x4x.c b/drivers/irqchip/irq-lp8x4x.c new file mode 100644 index 0000000..12ccbb03 --- /dev/null +++ b/drivers/irqchip/irq-lp8x4x.c @@ -0,0 +1,227 @@ +/* + * linux/drivers/irqchip/irq-lp8x4x.c + * + * Support for ICP DAS LP-8x4x FPGA irq + * Copyright (C) 2013 Sergei Ianovich <ynvich@xxxxxxxxx> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation or any later version. + */ +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/irq.h> +#include <linux/irqdomain.h> +#include <linux/irqchip/chained_irq.h> +#include <linux/of.h> +#include <linux/platform_device.h> + +#define EOI 0x00000000 +#define INSINT 0x00000002 +#define ENSYSINT 0x00000004 +#define PRIMINT 0x00000006 +#define PRIMINT_MASK 0xe0 +#define SECOINT 0x00000008 +#define SECOINT_MASK 0x1f +#define ENRISEINT 0x0000000A +#define CLRRISEINT 0x0000000C +#define ENHILVINT 0x0000000E +#define CLRHILVINT 0x00000010 +#define ENFALLINT 0x00000012 +#define CLRFALLINT 0x00000014 +#define IRQ_MEM_SIZE 0x00000016 +#define LP8X4X_NUM_IRQ_DEFAULT 16 + +/** + * struct lp8x4x_irq_data - LP8X4X custom irq controller state container + * @base: base IO memory address + * @irq_domain: Interrupt translation domain; responsible for mapping + * between hwirq number and linux irq number + * @irq_sys_enabled: mask keeping track of interrupts enabled in the + * register which vendor calls 'system' + * @irq_high_enabled: mask keeping track of interrupts enabled in the + * register which vendor calls 'high' + * + * The structure implements State Container from + * Documentation/driver-model/design-patterns.txt + */ + +struct lp8x4x_irq_data { + void *base; + struct irq_domain *domain; + unsigned char irq_sys_enabled; + unsigned char irq_high_enabled; +}; + +static void lp8x4x_mask_irq(struct irq_data *d) +{ + unsigned mask; + unsigned long hwirq = d->hwirq; + struct lp8x4x_irq_data *host = irq_data_get_irq_chip_data(d); + + if (hwirq < 8) { + host->irq_high_enabled &= ~BIT(hwirq); + + mask = ioread8(host->base + ENHILVINT); + mask &= ~BIT(hwirq); + iowrite8(mask, host->base + ENHILVINT); + } else { + hwirq -= 8; + host->irq_sys_enabled &= ~BIT(hwirq); + + mask = ioread8(host->base + ENSYSINT); + mask &= ~BIT(hwirq); + iowrite8(mask, host->base + ENSYSINT); + } +} + +static void lp8x4x_unmask_irq(struct irq_data *d) +{ + unsigned mask; + unsigned long hwirq = d->hwirq; + struct lp8x4x_irq_data *host = irq_data_get_irq_chip_data(d); + + if (hwirq < 8) { + host->irq_high_enabled |= BIT(hwirq); + mask = ioread8(host->base + CLRHILVINT); + mask |= BIT(hwirq); + iowrite8(mask, host->base + CLRHILVINT); + + mask = ioread8(host->base + ENHILVINT); + mask |= BIT(hwirq); + iowrite8(mask, host->base + ENHILVINT); + } else { + hwirq -= 8; + host->irq_sys_enabled |= BIT(hwirq); + + mask = ioread8(host->base + SECOINT); + mask |= BIT(hwirq); + iowrite8(mask, host->base + SECOINT); + + mask = ioread8(host->base + ENSYSINT); + mask |= BIT(hwirq); + iowrite8(mask, host->base + ENSYSINT); + } +} + +static struct irq_chip lp8x4x_irq_chip = { + .name = "FPGA", + .irq_ack = lp8x4x_mask_irq, + .irq_mask = lp8x4x_mask_irq, + .irq_mask_ack = lp8x4x_mask_irq, + .irq_unmask = lp8x4x_unmask_irq, +}; + +static void lp8x4x_irq_handler(unsigned int irq, struct irq_desc *desc) +{ + int n; + unsigned long mask; + struct irq_chip *chip = irq_desc_get_chip(desc); + struct lp8x4x_irq_data *host = irq_desc_get_handler_data(desc); + + chained_irq_enter(chip, desc); + + for (;;) { + mask = ioread8(host->base + CLRHILVINT) & 0xff; + mask |= (ioread8(host->base + SECOINT) & SECOINT_MASK) << 8; + mask |= (ioread8(host->base + PRIMINT) & PRIMINT_MASK) << 8; + mask &= host->irq_high_enabled | (host->irq_sys_enabled << 8); + if (mask == 0) + break; + for_each_set_bit(n, &mask, BITS_PER_LONG) + generic_handle_irq(irq_find_mapping(host->domain, n)); + } + + iowrite8(0, host->base + EOI); + chained_irq_exit(chip, desc); +} + +static int lp8x4x_irq_domain_map(struct irq_domain *d, unsigned int irq, + irq_hw_number_t hw) +{ + struct lp8x4x_irq_data *host = d->host_data; + int err; + + err = irq_set_chip_data(irq, host); + if (err < 0) + return err; + + irq_set_chip_and_handler(irq, &lp8x4x_irq_chip, handle_level_irq); + set_irq_flags(irq, IRQF_VALID | IRQF_PROBE); + return 0; +} + +const struct irq_domain_ops lp8x4x_irq_domain_ops = { + .map = lp8x4x_irq_domain_map, + .xlate = irq_domain_xlate_onecell, +}; + +static struct of_device_id lp8x4x_irq_dt_ids[] = { + { .compatible = "icpdas,irq-lp8x4x", }, + {} +}; + +static int lp8x4x_irq_probe(struct platform_device *pdev) +{ + struct resource *res_mem, *res_irq; + struct device_node *np = pdev->dev.of_node; + struct lp8x4x_irq_data *host; + int i, err; + + res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0); + if (!res_mem || !res_irq || resource_size(res_mem) < IRQ_MEM_SIZE) + return -ENODEV; + + host = devm_kzalloc(&pdev->dev, sizeof(*host), GFP_KERNEL); + if (!host) + return -ENODEV; + + host->base = devm_ioremap_resource(&pdev->dev, res_mem); + if (!host->base) { + dev_err(&pdev->dev, "Failed to ioremap %p\n", host->base); + return -EFAULT; + } + + host->domain = irq_domain_add_linear(np, LP8X4X_NUM_IRQ_DEFAULT, + &lp8x4x_irq_domain_ops, host); + if (!host->domain) { + dev_err(&pdev->dev, "Failed to add IRQ domain\n"); + return -ENOMEM; + } + + for (i = 0; i < LP8X4X_NUM_IRQ_DEFAULT; i++) { + err = irq_create_mapping(host->domain, i); + if (err < 0) + dev_err(&pdev->dev, "Failed to map IRQ %i\n", i); + } + + /* Initialize chip registers */ + iowrite8(0, host->base + CLRRISEINT); + iowrite8(0, host->base + ENRISEINT); + iowrite8(0, host->base + CLRFALLINT); + iowrite8(0, host->base + ENFALLINT); + iowrite8(0, host->base + CLRHILVINT); + iowrite8(0, host->base + ENHILVINT); + iowrite8(0, host->base + ENSYSINT); + iowrite8(0, host->base + SECOINT); + + irq_set_handler_data(res_irq->start, host); + irq_set_chained_handler(res_irq->start, lp8x4x_irq_handler); + + return 0; +} + +static struct platform_driver lp8x4x_irq_driver = { + .probe = lp8x4x_irq_probe, + .driver = { + .name = "irq-lp8x4x", + .of_match_table = lp8x4x_irq_dt_ids, + }, +}; + +static int __init lp8x4x_irq_init(void) +{ + return platform_driver_register(&lp8x4x_irq_driver); +} +postcore_initcall(lp8x4x_irq_init); -- 1.8.4.2 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html