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* Programmable Real-Time Unit Sub System (PRUSS) UIO driver (uio_pruss)
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* This driver exports PRUSS host event out interrupts and PRUSS, L3 RAM,
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* and DDR RAM to user space for applications interacting with PRUSS firmware
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* Copyright (C) 2010-11 Texas Instruments Incorporated - http://www.ti.com/
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation version 2.
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* This program is distributed "as is" WITHOUT ANY WARRANTY of any
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* kind, whether express or implied; without even the implied warranty
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* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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#include <linux/device.h>
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/platform_device.h>
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#include <linux/uio_driver.h>
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#include <linux/platform_data/uio_pruss.h>
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#include <linux/clk.h>
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#include <linux/dma-mapping.h>
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#include <linux/slab.h>
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#include <mach/sram.h>
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#define DRV_NAME "pruss_uio"
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#define DRV_VERSION "1.0"
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static int sram_pool_sz = SZ_16K;
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module_param(sram_pool_sz, int, 0);
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MODULE_PARM_DESC(sram_pool_sz, "sram pool size to allocate ");
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static int extram_pool_sz = SZ_256K;
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module_param(extram_pool_sz, int, 0);
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MODULE_PARM_DESC(extram_pool_sz, "external ram pool size to allocate");
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* Host event IRQ numbers from PRUSS - PRUSS can generate up to 8 interrupt
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* events to AINTC of ARM host processor - which can be used for IPC b/w PRUSS
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* firmware and user space application, async notification from PRU firmware
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* to user space application
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#define MAX_PRUSS_EVT 8
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#define PINTC_HIDISR 0x0038
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#define PINTC_HIPIR 0x0900
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#define HIPIR_NOPEND 0x80000000
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#define PINTC_HIER 0x1500
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struct uio_pruss_dev {
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struct uio_info *info;
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struct clk *pruss_clk;
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dma_addr_t sram_paddr;
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void __iomem *prussio_vaddr;
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unsigned int hostirq_start;
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unsigned int pintc_base;
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static irqreturn_t pruss_handler(int irq, struct uio_info *info)
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struct uio_pruss_dev *gdev = info->priv;
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int intr_bit = (irq - gdev->hostirq_start + 2);
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int val, intr_mask = (1 << intr_bit);
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void __iomem *base = gdev->prussio_vaddr + gdev->pintc_base;
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void __iomem *intren_reg = base + PINTC_HIER;
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void __iomem *intrdis_reg = base + PINTC_HIDISR;
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void __iomem *intrstat_reg = base + PINTC_HIPIR + (intr_bit << 2);
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val = ioread32(intren_reg);
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/* Is interrupt enabled and active ? */
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if (!(val & intr_mask) && (ioread32(intrstat_reg) & HIPIR_NOPEND))
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/* Disable interrupt */
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iowrite32(intr_bit, intrdis_reg);
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static void pruss_cleanup(struct platform_device *dev,
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struct uio_pruss_dev *gdev)
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struct uio_info *p = gdev->info;
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for (cnt = 0; cnt < MAX_PRUSS_EVT; cnt++, p++) {
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uio_unregister_device(p);
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iounmap(gdev->prussio_vaddr);
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if (gdev->ddr_vaddr) {
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dma_free_coherent(&dev->dev, extram_pool_sz, gdev->ddr_vaddr,
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if (gdev->sram_vaddr)
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sram_free(gdev->sram_vaddr, sram_pool_sz);
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clk_put(gdev->pruss_clk);
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static int __devinit pruss_probe(struct platform_device *dev)
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struct uio_pruss_dev *gdev;
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struct resource *regs_prussio;
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int ret = -ENODEV, cnt = 0, len;
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struct uio_pruss_pdata *pdata = dev->dev.platform_data;
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gdev = kzalloc(sizeof(struct uio_pruss_dev), GFP_KERNEL);
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gdev->info = kzalloc(sizeof(*p) * MAX_PRUSS_EVT, GFP_KERNEL);
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/* Power on PRU in case its not done as part of boot-loader */
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gdev->pruss_clk = clk_get(&dev->dev, "pruss");
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if (IS_ERR(gdev->pruss_clk)) {
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dev_err(&dev->dev, "Failed to get clock\n");
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ret = PTR_ERR(gdev->pruss_clk);
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clk_enable(gdev->pruss_clk);
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regs_prussio = platform_get_resource(dev, IORESOURCE_MEM, 0);
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dev_err(&dev->dev, "No PRUSS I/O resource specified\n");
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if (!regs_prussio->start) {
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dev_err(&dev->dev, "Invalid memory resource\n");
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gdev->sram_vaddr = sram_alloc(sram_pool_sz, &(gdev->sram_paddr));
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if (!gdev->sram_vaddr) {
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dev_err(&dev->dev, "Could not allocate SRAM pool\n");
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gdev->ddr_vaddr = dma_alloc_coherent(&dev->dev, extram_pool_sz,
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&(gdev->ddr_paddr), GFP_KERNEL | GFP_DMA);
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if (!gdev->ddr_vaddr) {
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dev_err(&dev->dev, "Could not allocate external memory\n");
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len = resource_size(regs_prussio);
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gdev->prussio_vaddr = ioremap(regs_prussio->start, len);
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if (!gdev->prussio_vaddr) {
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dev_err(&dev->dev, "Can't remap PRUSS I/O address range\n");
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gdev->pintc_base = pdata->pintc_base;
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gdev->hostirq_start = platform_get_irq(dev, 0);
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for (cnt = 0, p = gdev->info; cnt < MAX_PRUSS_EVT; cnt++, p++) {
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p->mem[0].addr = regs_prussio->start;
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p->mem[0].size = resource_size(regs_prussio);
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p->mem[0].memtype = UIO_MEM_PHYS;
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p->mem[1].addr = gdev->sram_paddr;
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p->mem[1].size = sram_pool_sz;
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p->mem[1].memtype = UIO_MEM_PHYS;
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p->mem[2].addr = gdev->ddr_paddr;
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p->mem[2].size = extram_pool_sz;
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p->mem[2].memtype = UIO_MEM_PHYS;
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p->name = kasprintf(GFP_KERNEL, "pruss_evt%d", cnt);
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p->version = DRV_VERSION;
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/* Register PRUSS IRQ lines */
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p->irq = gdev->hostirq_start + cnt;
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p->handler = pruss_handler;
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ret = uio_register_device(&dev->dev, p);
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platform_set_drvdata(dev, gdev);
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pruss_cleanup(dev, gdev);
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static int __devexit pruss_remove(struct platform_device *dev)
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struct uio_pruss_dev *gdev = platform_get_drvdata(dev);
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pruss_cleanup(dev, gdev);
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platform_set_drvdata(dev, NULL);
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static struct platform_driver pruss_driver = {
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.probe = pruss_probe,
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.remove = __devexit_p(pruss_remove),
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.owner = THIS_MODULE,
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static int __init pruss_init_module(void)
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return platform_driver_register(&pruss_driver);
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module_init(pruss_init_module);
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static void __exit pruss_exit_module(void)
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platform_driver_unregister(&pruss_driver);
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module_exit(pruss_exit_module);
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MODULE_LICENSE("GPL v2");
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MODULE_VERSION(DRV_VERSION);
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MODULE_AUTHOR("Amit Chatterjee <amit.chatterjee@ti.com>");
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MODULE_AUTHOR("Pratheesh Gangadhar <pratheesh@ti.com>");