Message-ID: <20110305003004.GA1295@local>
Date:	Sat, 5 Mar 2011 01:30:04 +0100
From:	"Hans J. Koch" <hjk@...sjkoch.de>
To:	Pratheesh Gangadhar <pratheesh@...com>
Cc:	linux-kernel@...r.kernel.org, hjk@...sjkoch.de, gregkh@...e.de,
	tglx@...utronix.de, sshtylyov@...sta.com, arnd@...db.de,
	amit.chatterjee@...com,
	davinci-linux-open-source@...ux.davincidsp.com,
	linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH v11 1/1] PRUSS UIO driver support

On Sat, Mar 05, 2011 at 04:30:17AM +0530, Pratheesh Gangadhar wrote:
> This patch implements PRUSS (Programmable Real-time Unit Sub System)
> UIO driver which exports SOC resources associated with PRUSS like
> I/O, memories and IRQs to user space. PRUSS is dual 32-bit RISC
> processors which is efficient in performing embedded tasks that
> require manipulation of packed memory mapped data structures and
> handling system events that have tight real time constraints. This
> driver is currently supported on Texas Instruments DA850, AM18xx and
> OMAP-L138 devices.
> For example, PRUSS runs firmware for real-time critical industrial
> communication data link layer and communicates with application stack
> running in user space via shared memory and IRQs.
> 
> Signed-off-by: Pratheesh Gangadhar <pratheesh@...com>
> Reviewed-by: Thomas Gleixner <tglx@...utronix.de>
> Reviewed-by: Arnd Bergmann <arnd@...db.de>

Signed-off-by: Hans J. Koch <hjk@...sjkoch.de>

I think, we've got it. Thanks for your contribution and your patience.
Not many UIO programmers hang on through 11 patch versions...

Thanks,
Hans

> ---
>  drivers/uio/Kconfig                     |   17 ++
>  drivers/uio/Makefile                    |    1 +
>  drivers/uio/uio_pruss.c                 |  247 +++++++++++++++++++++++++++++++
>  include/linux/platform_data/uio_pruss.h |   25 +++
>  4 files changed, 290 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/uio/uio_pruss.c
>  create mode 100644 include/linux/platform_data/uio_pruss.h
> 
> diff --git a/drivers/uio/Kconfig b/drivers/uio/Kconfig
> index bb44079..6f3ea9b 100644
> --- a/drivers/uio/Kconfig
> +++ b/drivers/uio/Kconfig
> @@ -94,4 +94,21 @@ config UIO_NETX
>  	  To compile this driver as a module, choose M here; the module
>  	  will be called uio_netx.
>  
> +config UIO_PRUSS
> +	tristate "Texas Instruments PRUSS driver"
> +	depends on ARCH_DAVINCI_DA850
> +	help
> +	  PRUSS driver for OMAPL138/DA850/AM18XX devices
> +	  PRUSS driver requires user space components, examples and user space
> +	  driver is available from below SVN repo - you may use anonymous login
> +
> +	  https://gforge.ti.com/gf/project/pru_sw/
> +
> +	  More info on API is available at below wiki
> +
> +	  http://processors.wiki.ti.com/index.php/PRU_Linux_Application_Loader
> +
> +	  To compile this driver as a module, choose M here: the module
> +	  will be called uio_pruss.
> +
>  endif
> diff --git a/drivers/uio/Makefile b/drivers/uio/Makefile
> index 18fd818..d4dd9a5 100644
> --- a/drivers/uio/Makefile
> +++ b/drivers/uio/Makefile
> @@ -6,3 +6,4 @@ obj-$(CONFIG_UIO_AEC)	+= uio_aec.o
>  obj-$(CONFIG_UIO_SERCOS3)	+= uio_sercos3.o
>  obj-$(CONFIG_UIO_PCI_GENERIC)	+= uio_pci_generic.o
>  obj-$(CONFIG_UIO_NETX)	+= uio_netx.o
> +obj-$(CONFIG_UIO_PRUSS)         += uio_pruss.o
> diff --git a/drivers/uio/uio_pruss.c b/drivers/uio/uio_pruss.c
> new file mode 100644
> index 0000000..daf6e77
> --- /dev/null
> +++ b/drivers/uio/uio_pruss.c
> @@ -0,0 +1,247 @@
> +/*
> + * Programmable Real-Time Unit Sub System (PRUSS) UIO driver (uio_pruss)
> + *
> + * This driver exports PRUSS host event out interrupts and PRUSS, L3 RAM,
> + * and DDR RAM to user space for applications interacting with PRUSS firmware
> + *
> + * Copyright (C) 2010-11 Texas Instruments Incorporated - http://www.ti.com/
> + *
> + * 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.
> + */
> +#include <linux/device.h>
> +#include <linux/module.h>
> +#include <linux/moduleparam.h>
> +#include <linux/platform_device.h>
> +#include <linux/uio_driver.h>
> +#include <linux/platform_data/uio_pruss.h>
> +#include <linux/io.h>
> +#include <linux/clk.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/slab.h>
> +#include <mach/sram.h>
> +
> +#define DRV_NAME "pruss_uio"
> +#define DRV_VERSION "1.0"
> +
> +static int sram_pool_sz = SZ_16K;
> +module_param(sram_pool_sz, int, 0);
> +MODULE_PARM_DESC(sram_pool_sz, "sram pool size to allocate ");
> +
> +static int extram_pool_sz = SZ_256K;
> +module_param(extram_pool_sz, int, 0);
> +MODULE_PARM_DESC(extram_pool_sz, "external ram pool size to allocate");
> +
> +/*
> + * Host event IRQ numbers from PRUSS - PRUSS can generate upto 8 interrupt
> + * events to AINTC of ARM host processor - which can be used for IPC b/w PRUSS
> + * firmware and user space application, async notification from PRU firmware
> + * to user space application
> + * 3	PRU_EVTOUT0
> + * 4	PRU_EVTOUT1
> + * 5	PRU_EVTOUT2
> + * 6	PRU_EVTOUT3
> + * 7	PRU_EVTOUT4
> + * 8	PRU_EVTOUT5
> + * 9	PRU_EVTOUT6
> + * 10	PRU_EVTOUT7
> +*/
> +#define MAX_PRUSS_EVT	8
> +
> +#define PINTC_HIDISR	0x0038
> +#define PINTC_HIPIR	0x0900
> +#define HIPIR_NOPEND	0x80000000
> +#define PINTC_HIER	0x1500
> +
> +struct uio_pruss_dev {
> +	struct uio_info *info;
> +	struct clk *pruss_clk;
> +	dma_addr_t sram_paddr;
> +	dma_addr_t ddr_paddr;
> +	void __iomem *prussio_vaddr;
> +	void *sram_vaddr;
> +	void *ddr_vaddr;
> +	unsigned int hostirq_start;
> +	unsigned int pintc_base;
> +};
> +
> +static irqreturn_t pruss_handler(int irq, struct uio_info *info)
> +{
> +	struct uio_pruss_dev *gdev = info->priv;
> +	int intr_bit = (irq - gdev->hostirq_start + 2);
> +	int val, intr_mask = (1 << intr_bit);
> +	void __iomem *base = gdev->prussio_vaddr + gdev->pintc_base;
> +	void __iomem *intren_reg = base + PINTC_HIER;
> +	void __iomem *intrdis_reg = base + PINTC_HIDISR;
> +	void __iomem *intrstat_reg = base + PINTC_HIPIR + (intr_bit << 2);
> +
> +	val = ioread32(intren_reg);
> +	/* Is interrupt enabled and active ? */
> +	if (!(val & intr_mask) && (ioread32(intrstat_reg) & HIPIR_NOPEND))
> +		return IRQ_NONE;
> +	/* Disable interrupt */
> +	iowrite32(intr_bit, intrdis_reg);
> +	return IRQ_HANDLED;
> +}
> +
> +static void pruss_cleanup(struct platform_device *dev,
> +			struct uio_pruss_dev *gdev)
> +{
> +	int cnt;
> +	struct uio_info *p = gdev->info;
> +
> +	for (cnt = 0; cnt < MAX_PRUSS_EVT; cnt++, p++) {
> +		uio_unregister_device(p);
> +		kfree(p->name);
> +	}
> +	iounmap(gdev->prussio_vaddr);
> +	if (gdev->ddr_vaddr) {
> +		dma_free_coherent(&dev->dev, extram_pool_sz, gdev->ddr_vaddr,
> +			gdev->ddr_paddr);
> +	}
> +	if (gdev->sram_vaddr)
> +		sram_free(gdev->sram_vaddr, sram_pool_sz);
> +	kfree(gdev->info);
> +	clk_put(gdev->pruss_clk);
> +	kfree(gdev);
> +}
> +
> +static int __devinit pruss_probe(struct platform_device *dev)
> +{
> +	struct uio_info *p;
> +	struct uio_pruss_dev *gdev;
> +	struct resource *regs_prussio;
> +	int ret = -ENODEV, cnt = 0, len;
> +	struct uio_pruss_pdata *pdata = dev->dev.platform_data;
> +
> +	gdev = kzalloc(sizeof(struct uio_pruss_dev), GFP_KERNEL);
> +	if (!gdev)
> +		return -ENOMEM;
> +
> +	gdev->info = kzalloc(sizeof(*p) * MAX_PRUSS_EVT, GFP_KERNEL);
> +	if (!gdev->info) {
> +		kfree(gdev);
> +		return -ENOMEM;
> +	}
> +	/* Power on PRU in case its not done as part of boot-loader */
> +	gdev->pruss_clk = clk_get(&dev->dev, "pruss");
> +	if (IS_ERR(gdev->pruss_clk)) {
> +		dev_err(&dev->dev, "Failed to get clock\n");
> +		kfree(gdev->info);
> +		kfree(gdev);
> +		ret = PTR_ERR(gdev->pruss_clk);
> +		return ret;
> +	} else {
> +		clk_enable(gdev->pruss_clk);
> +	}
> +
> +	regs_prussio = platform_get_resource(dev, IORESOURCE_MEM, 0);
> +	if (!regs_prussio) {
> +		dev_err(&dev->dev, "No PRUSS I/O resource specified\n");
> +		goto out_free;
> +	}
> +
> +	if (!regs_prussio->start) {
> +		dev_err(&dev->dev, "Invalid memory resource\n");
> +		goto out_free;
> +	}
> +
> +	gdev->sram_vaddr = sram_alloc(sram_pool_sz, &(gdev->sram_paddr));
> +	if (!gdev->sram_vaddr) {
> +		dev_err(&dev->dev, "Could not allocate SRAM pool\n");
> +		goto out_free;
> +	}
> +
> +	gdev->ddr_vaddr = dma_alloc_coherent(&dev->dev, extram_pool_sz,
> +				&(gdev->ddr_paddr), GFP_KERNEL | GFP_DMA);
> +	if (!gdev->ddr_vaddr) {
> +		dev_err(&dev->dev, "Could not allocate external memory\n");
> +		goto out_free;
> +	}
> +
> +	len = resource_size(regs_prussio);
> +	gdev->prussio_vaddr = ioremap(regs_prussio->start, len);
> +	if (!gdev->prussio_vaddr) {
> +		dev_err(&dev->dev, "Can't remap PRUSS I/O  address range\n");
> +		goto out_free;
> +	}
> +
> +	gdev->pintc_base = pdata->pintc_base;
> +	gdev->hostirq_start = platform_get_irq(dev, 0);
> +
> +	for (cnt = 0, p = gdev->info; cnt < MAX_PRUSS_EVT; cnt++, p++) {
> +		p->mem[0].addr = regs_prussio->start;
> +		p->mem[0].size = resource_size(regs_prussio);
> +		p->mem[0].memtype = UIO_MEM_PHYS;
> +
> +		p->mem[1].addr = gdev->sram_paddr;
> +		p->mem[1].size = sram_pool_sz;
> +		p->mem[1].memtype = UIO_MEM_PHYS;
> +
> +		p->mem[2].addr = gdev->ddr_paddr;
> +		p->mem[2].size = extram_pool_sz;
> +		p->mem[2].memtype = UIO_MEM_PHYS;
> +
> +		p->name = kasprintf(GFP_KERNEL, "pruss_evt%d", cnt);
> +		p->version = DRV_VERSION;
> +
> +		/* Register PRUSS IRQ lines */
> +		p->irq = gdev->hostirq_start + cnt;
> +		p->handler = pruss_handler;
> +		p->priv = gdev;
> +
> +		ret = uio_register_device(&dev->dev, p);
> +		if (ret < 0)
> +			goto out_free;
> +	}
> +
> +	platform_set_drvdata(dev, gdev);
> +	return 0;
> +
> +out_free:
> +	pruss_cleanup(dev, gdev);
> +	return ret;
> +}
> +
> +static int __devexit pruss_remove(struct platform_device *dev)
> +{
> +	struct uio_pruss_dev *gdev = platform_get_drvdata(dev);
> +
> +	pruss_cleanup(dev, gdev);
> +	platform_set_drvdata(dev, NULL);
> +	return 0;
> +}
> +
> +static struct platform_driver pruss_driver = {
> +	.probe = pruss_probe,
> +	.remove = __devexit_p(pruss_remove),
> +	.driver = {
> +		   .name = DRV_NAME,
> +		   .owner = THIS_MODULE,
> +		   },
> +};
> +
> +static int __init pruss_init_module(void)
> +{
> +	return platform_driver_register(&pruss_driver);
> +}
> +
> +module_init(pruss_init_module);
> +
> +static void __exit pruss_exit_module(void)
> +{
> +	platform_driver_unregister(&pruss_driver);
> +}
> +
> +module_exit(pruss_exit_module);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_VERSION(DRV_VERSION);
> +MODULE_AUTHOR("Amit Chatterjee <amit.chatterjee@...com>");
> +MODULE_AUTHOR("Pratheesh Gangadhar <pratheesh@...com>");
> diff --git a/include/linux/platform_data/uio_pruss.h b/include/linux/platform_data/uio_pruss.h
> new file mode 100644
> index 0000000..f39140a
> --- /dev/null
> +++ b/include/linux/platform_data/uio_pruss.h
> @@ -0,0 +1,25 @@
> +/*
> + * include/linux/platform_data/uio_pruss.h
> + *
> + * Platform data for uio_pruss driver
> + *
> + * Copyright (C) 2010-11 Texas Instruments Incorporated - http://www.ti.com/
> + *
> + * 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_PRUSS_H_
> +#define _UIO_PRUSS_H_
> +
> +/* To configure the PRUSS INTC base offset for UIO driver */
> +struct uio_pruss_pdata {
> +	u32	pintc_base;
> +};
> +#endif /* _UIO_PRUSS_H_ */
> -- 
> 1.6.0.6
> 
> 
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