diff options
| -rw-r--r-- | drivers/uio/Kconfig | 16 | ||||
| -rw-r--r-- | drivers/uio/Makefile | 1 | ||||
| -rw-r--r-- | drivers/uio/uio_dmem_genirq.c | 354 | ||||
| -rw-r--r-- | include/linux/platform_data/uio_dmem_genirq.h | 26 |
4 files changed, 397 insertions, 0 deletions
diff --git a/drivers/uio/Kconfig b/drivers/uio/Kconfig index 6f3ea9bbc818..82e2b89d4480 100644 --- a/drivers/uio/Kconfig +++ b/drivers/uio/Kconfig @@ -44,6 +44,22 @@ config UIO_PDRV_GENIRQ If you don't know what to do here, say N. +config UIO_DMEM_GENIRQ + tristate "Userspace platform driver with generic irq and dynamic memory" + help + Platform driver for Userspace I/O devices, including generic + interrupt handling code. Shared interrupts are not supported. + + Memory regions can be specified with the same platform device + resources as the UIO_PDRV drivers, but dynamic regions can also + be specified. + The number and size of these regions is static, + but the memory allocation is not performed until + the associated device file is opened. The + memory is freed once the uio device is closed. + + If you don't know what to do here, say N. + config UIO_AEC tristate "AEC video timestamp device" depends on PCI diff --git a/drivers/uio/Makefile b/drivers/uio/Makefile index d4dd9a5552f8..b354c539507a 100644 --- a/drivers/uio/Makefile +++ b/drivers/uio/Makefile @@ -2,6 +2,7 @@ obj-$(CONFIG_UIO) += uio.o obj-$(CONFIG_UIO_CIF) += uio_cif.o obj-$(CONFIG_UIO_PDRV) += uio_pdrv.o obj-$(CONFIG_UIO_PDRV_GENIRQ) += uio_pdrv_genirq.o +obj-$(CONFIG_UIO_DMEM_GENIRQ) += uio_dmem_genirq.o obj-$(CONFIG_UIO_AEC) += uio_aec.o obj-$(CONFIG_UIO_SERCOS3) += uio_sercos3.o obj-$(CONFIG_UIO_PCI_GENERIC) += uio_pci_generic.o diff --git a/drivers/uio/uio_dmem_genirq.c b/drivers/uio/uio_dmem_genirq.c new file mode 100644 index 000000000000..4d4dd008c8b9 --- /dev/null +++ b/drivers/uio/uio_dmem_genirq.c @@ -0,0 +1,354 @@ +/* + * drivers/uio/uio_dmem_genirq.c + * + * Userspace I/O platform driver with generic IRQ handling code. + * + * Copyright (C) 2012 Damian Hobson-Garcia + * + * Based on uio_pdrv_genirq.c by Magnus Damm + * + * 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. + */ + +#include <linux/platform_device.h> +#include <linux/uio_driver.h> +#include <linux/spinlock.h> +#include <linux/bitops.h> +#include <linux/module.h> +#include <linux/interrupt.h> +#include <linux/platform_data/uio_dmem_genirq.h> +#include <linux/stringify.h> +#include <linux/pm_runtime.h> +#include <linux/dma-mapping.h> +#include <linux/slab.h> + +#include <linux/of.h> +#include <linux/of_platform.h> +#include <linux/of_address.h> + +#define DRIVER_NAME "uio_dmem_genirq" + +struct uio_dmem_genirq_platdata { + struct uio_info *uioinfo; + spinlock_t lock; + unsigned long flags; + struct platform_device *pdev; + unsigned int dmem_region_start; + unsigned int num_dmem_regions; + struct mutex alloc_lock; + unsigned int refcnt; +}; + +static int uio_dmem_genirq_open(struct uio_info *info, struct inode *inode) +{ + struct uio_dmem_genirq_platdata *priv = info->priv; + struct uio_mem *uiomem; + int ret = 0; + + uiomem = &priv->uioinfo->mem[priv->dmem_region_start]; + + mutex_lock(&priv->alloc_lock); + while (!priv->refcnt && uiomem < &priv->uioinfo->mem[MAX_UIO_MAPS]) { + void *addr; + if (!uiomem->size) + break; + + addr = dma_alloc_coherent(&priv->pdev->dev, uiomem->size, + (dma_addr_t *)&uiomem->addr, GFP_KERNEL); + if (!addr) { + ret = -ENOMEM; + break; + } + + uiomem->internal_addr = addr; + ++uiomem; + } + priv->refcnt++; + + mutex_unlock(&priv->alloc_lock); + /* Wait until the Runtime PM code has woken up the device */ + pm_runtime_get_sync(&priv->pdev->dev); + return ret; +} + +static int uio_dmem_genirq_release(struct uio_info *info, struct inode *inode) +{ + struct uio_dmem_genirq_platdata *priv = info->priv; + struct uio_mem *uiomem; + + /* Tell the Runtime PM code that the device has become idle */ + pm_runtime_put_sync(&priv->pdev->dev); + + uiomem = &priv->uioinfo->mem[priv->dmem_region_start]; + + mutex_lock(&priv->alloc_lock); + + priv->refcnt--; + while (!priv->refcnt && uiomem < &priv->uioinfo->mem[MAX_UIO_MAPS]) { + if (!uiomem->size) + break; + + dma_free_coherent(&priv->pdev->dev, uiomem->size, + uiomem->internal_addr, uiomem->addr); + uiomem->addr = DMA_ERROR_CODE; + ++uiomem; + } + + mutex_unlock(&priv->alloc_lock); + return 0; +} + +static irqreturn_t uio_dmem_genirq_handler(int irq, struct uio_info *dev_info) +{ + struct uio_dmem_genirq_platdata *priv = dev_info->priv; + + /* Just disable the interrupt in the interrupt controller, and + * remember the state so we can allow user space to enable it later. + */ + + if (!test_and_set_bit(0, &priv->flags)) + disable_irq_nosync(irq); + + return IRQ_HANDLED; +} + +static int uio_dmem_genirq_irqcontrol(struct uio_info *dev_info, s32 irq_on) +{ + struct uio_dmem_genirq_platdata *priv = dev_info->priv; + unsigned long flags; + + /* Allow user space to enable and disable the interrupt + * in the interrupt controller, but keep track of the + * state to prevent per-irq depth damage. + * + * Serialize this operation to support multiple tasks. + */ + + spin_lock_irqsave(&priv->lock, flags); + if (irq_on) { + if (test_and_clear_bit(0, &priv->flags)) + enable_irq(dev_info->irq); + } else { + if (!test_and_set_bit(0, &priv->flags)) + disable_irq(dev_info->irq); + } + spin_unlock_irqrestore(&priv->lock, flags); + + return 0; +} + +static int uio_dmem_genirq_probe(struct platform_device *pdev) +{ + struct uio_dmem_genirq_pdata *pdata = pdev->dev.platform_data; + struct uio_info *uioinfo = &pdata->uioinfo; + struct uio_dmem_genirq_platdata *priv; + struct uio_mem *uiomem; + int ret = -EINVAL; + int i; + + if (!uioinfo) { + int irq; + + /* alloc uioinfo for one device */ + uioinfo = kzalloc(sizeof(*uioinfo), GFP_KERNEL); + if (!uioinfo) { + ret = -ENOMEM; + dev_err(&pdev->dev, "unable to kmalloc\n"); + goto bad2; + } + uioinfo->name = pdev->dev.of_node->name; + uioinfo->version = "devicetree"; + + /* Multiple IRQs are not supported */ + irq = platform_get_irq(pdev, 0); + if (irq == -ENXIO) + uioinfo->irq = UIO_IRQ_NONE; + else + uioinfo->irq = irq; + } + + if (!uioinfo || !uioinfo->name || !uioinfo->version) { + dev_err(&pdev->dev, "missing platform_data\n"); + goto bad0; + } + + if (uioinfo->handler || uioinfo->irqcontrol || + uioinfo->irq_flags & IRQF_SHARED) { + dev_err(&pdev->dev, "interrupt configuration error\n"); + goto bad0; + } + + priv = kzalloc(sizeof(*priv), GFP_KERNEL); + if (!priv) { + ret = -ENOMEM; + dev_err(&pdev->dev, "unable to kmalloc\n"); + goto bad0; + } + + dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(32)); + + priv->uioinfo = uioinfo; + spin_lock_init(&priv->lock); + priv->flags = 0; /* interrupt is enabled to begin with */ + priv->pdev = pdev; + mutex_init(&priv->alloc_lock); + + if (!uioinfo->irq) { + ret = platform_get_irq(pdev, 0); + if (ret < 0) { + dev_err(&pdev->dev, "failed to get IRQ\n"); + goto bad0; + } + uioinfo->irq = ret; + } + uiomem = &uioinfo->mem[0]; + + for (i = 0; i < pdev->num_resources; ++i) { + struct resource *r = &pdev->resource[i]; + + if (r->flags != IORESOURCE_MEM) + continue; + + if (uiomem >= &uioinfo->mem[MAX_UIO_MAPS]) { + dev_warn(&pdev->dev, "device has more than " + __stringify(MAX_UIO_MAPS) + " I/O memory resources.\n"); + break; + } + + uiomem->memtype = UIO_MEM_PHYS; + uiomem->addr = r->start; + uiomem->size = resource_size(r); + ++uiomem; + } + + priv->dmem_region_start = i; + priv->num_dmem_regions = pdata->num_dynamic_regions; + + for (i = 0; i < pdata->num_dynamic_regions; ++i) { + if (uiomem >= &uioinfo->mem[MAX_UIO_MAPS]) { + dev_warn(&pdev->dev, "device has more than " + __stringify(MAX_UIO_MAPS) + " dynamic and fixed memory regions.\n"); + break; + } + uiomem->memtype = UIO_MEM_PHYS; + uiomem->addr = DMA_ERROR_CODE; + uiomem->size = pdata->dynamic_region_sizes[i]; + ++uiomem; + } + + while (uiomem < &uioinfo->mem[MAX_UIO_MAPS]) { + uiomem->size = 0; + ++uiomem; + } + + /* This driver requires no hardware specific kernel code to handle + * interrupts. Instead, the interrupt handler simply disables the + * interrupt in the interrupt controller. User space is responsible + * for performing hardware specific acknowledge and re-enabling of + * the interrupt in the interrupt controller. + * + * Interrupt sharing is not supported. + */ + + uioinfo->handler = uio_dmem_genirq_handler; + uioinfo->irqcontrol = uio_dmem_genirq_irqcontrol; + uioinfo->open = uio_dmem_genirq_open; + uioinfo->release = uio_dmem_genirq_release; + uioinfo->priv = priv; + + /* Enable Runtime PM for this device: + * The device starts in suspended state to allow the hardware to be + * turned off by default. The Runtime PM bus code should power on the + * hardware and enable clocks at open(). + */ + pm_runtime_enable(&pdev->dev); + + ret = uio_register_device(&pdev->dev, priv->uioinfo); + if (ret) { + dev_err(&pdev->dev, "unable to register uio device\n"); + goto bad1; + } + + platform_set_drvdata(pdev, priv); + return 0; + bad1: + kfree(priv); + pm_runtime_disable(&pdev->dev); + bad0: + /* kfree uioinfo for OF */ + if (pdev->dev.of_node) + kfree(uioinfo); + bad2: + return ret; +} + +static int uio_dmem_genirq_remove(struct platform_device *pdev) +{ + struct uio_dmem_genirq_platdata *priv = platform_get_drvdata(pdev); + + uio_unregister_device(priv->uioinfo); + pm_runtime_disable(&pdev->dev); + + priv->uioinfo->handler = NULL; + priv->uioinfo->irqcontrol = NULL; + + /* kfree uioinfo for OF */ + if (pdev->dev.of_node) + kfree(priv->uioinfo); + + kfree(priv); + return 0; +} + +static int uio_dmem_genirq_runtime_nop(struct device *dev) +{ + /* Runtime PM callback shared between ->runtime_suspend() + * and ->runtime_resume(). Simply returns success. + * + * In this driver pm_runtime_get_sync() and pm_runtime_put_sync() + * are used at open() and release() time. This allows the + * Runtime PM code to turn off power to the device while the + * device is unused, ie before open() and after release(). + * + * This Runtime PM callback does not need to save or restore + * any registers since user space is responsbile for hardware + * register reinitialization after open(). + */ + return 0; +} + +static const struct dev_pm_ops uio_dmem_genirq_dev_pm_ops = { + .runtime_suspend = uio_dmem_genirq_runtime_nop, + .runtime_resume = uio_dmem_genirq_runtime_nop, +}; + +#ifdef CONFIG_OF +static const struct of_device_id uio_of_genirq_match[] = { + { /* empty for now */ }, +}; +MODULE_DEVICE_TABLE(of, uio_of_genirq_match); +#else +# define uio_of_genirq_match NULL +#endif + +static struct platform_driver uio_dmem_genirq = { + .probe = uio_dmem_genirq_probe, + .remove = uio_dmem_genirq_remove, + .driver = { + .name = DRIVER_NAME, + .owner = THIS_MODULE, + .pm = &uio_dmem_genirq_dev_pm_ops, + .of_match_table = uio_of_genirq_match, + }, +}; + +module_platform_driver(uio_dmem_genirq); + +MODULE_AUTHOR("Damian Hobson-Garcia"); +MODULE_DESCRIPTION("Userspace I/O platform driver with dynamic memory."); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:" DRIVER_NAME); diff --git a/include/linux/platform_data/uio_dmem_genirq.h b/include/linux/platform_data/uio_dmem_genirq.h new file mode 100644 index 000000000000..973c1bb32168 --- /dev/null +++ b/include/linux/platform_data/uio_dmem_genirq.h @@ -0,0 +1,26 @@ +/* + * include/linux/platform_data/uio_dmem_genirq.h + * + * Copyright (C) 2012 Damian Hobson-Garcia + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation version 2. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any + * kind, whether express or implied; without even the implied warranty + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#ifndef _UIO_DMEM_GENIRQ_H +#define _UIO_DMEM_GENIRQ_H + +#include <linux/uio_driver.h> + +struct uio_dmem_genirq_pdata { + struct uio_info uioinfo; + unsigned int *dynamic_region_sizes; + unsigned int num_dynamic_regions; +}; +#endif /* _UIO_DMEM_GENIRQ_H */ |
