linux/drivers/uio/uio_pruss.c
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   1/*
   2 * Programmable Real-Time Unit Sub System (PRUSS) UIO driver (uio_pruss)
   3 *
   4 * This driver exports PRUSS host event out interrupts and PRUSS, L3 RAM,
   5 * and DDR RAM to user space for applications interacting with PRUSS firmware
   6 *
   7 * Copyright (C) 2010-11 Texas Instruments Incorporated - http://www.ti.com/
   8 *
   9 * This program is free software; you can redistribute it and/or
  10 * modify it under the terms of the GNU General Public License as
  11 * published by the Free Software Foundation version 2.
  12 *
  13 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
  14 * kind, whether express or implied; without even the implied warranty
  15 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 * GNU General Public License for more details.
  17 */
  18#include <linux/device.h>
  19#include <linux/module.h>
  20#include <linux/moduleparam.h>
  21#include <linux/platform_device.h>
  22#include <linux/uio_driver.h>
  23#include <linux/platform_data/uio_pruss.h>
  24#include <linux/io.h>
  25#include <linux/clk.h>
  26#include <linux/dma-mapping.h>
  27#include <linux/slab.h>
  28#include <mach/sram.h>
  29
  30#define DRV_NAME "pruss_uio"
  31#define DRV_VERSION "1.0"
  32
  33static int sram_pool_sz = SZ_16K;
  34module_param(sram_pool_sz, int, 0);
  35MODULE_PARM_DESC(sram_pool_sz, "sram pool size to allocate ");
  36
  37static int extram_pool_sz = SZ_256K;
  38module_param(extram_pool_sz, int, 0);
  39MODULE_PARM_DESC(extram_pool_sz, "external ram pool size to allocate");
  40
  41/*
  42 * Host event IRQ numbers from PRUSS - PRUSS can generate up to 8 interrupt
  43 * events to AINTC of ARM host processor - which can be used for IPC b/w PRUSS
  44 * firmware and user space application, async notification from PRU firmware
  45 * to user space application
  46 * 3    PRU_EVTOUT0
  47 * 4    PRU_EVTOUT1
  48 * 5    PRU_EVTOUT2
  49 * 6    PRU_EVTOUT3
  50 * 7    PRU_EVTOUT4
  51 * 8    PRU_EVTOUT5
  52 * 9    PRU_EVTOUT6
  53 * 10   PRU_EVTOUT7
  54*/
  55#define MAX_PRUSS_EVT   8
  56
  57#define PINTC_HIDISR    0x0038
  58#define PINTC_HIPIR     0x0900
  59#define HIPIR_NOPEND    0x80000000
  60#define PINTC_HIER      0x1500
  61
  62struct uio_pruss_dev {
  63        struct uio_info *info;
  64        struct clk *pruss_clk;
  65        dma_addr_t sram_paddr;
  66        dma_addr_t ddr_paddr;
  67        void __iomem *prussio_vaddr;
  68        void *sram_vaddr;
  69        void *ddr_vaddr;
  70        unsigned int hostirq_start;
  71        unsigned int pintc_base;
  72};
  73
  74static irqreturn_t pruss_handler(int irq, struct uio_info *info)
  75{
  76        struct uio_pruss_dev *gdev = info->priv;
  77        int intr_bit = (irq - gdev->hostirq_start + 2);
  78        int val, intr_mask = (1 << intr_bit);
  79        void __iomem *base = gdev->prussio_vaddr + gdev->pintc_base;
  80        void __iomem *intren_reg = base + PINTC_HIER;
  81        void __iomem *intrdis_reg = base + PINTC_HIDISR;
  82        void __iomem *intrstat_reg = base + PINTC_HIPIR + (intr_bit << 2);
  83
  84        val = ioread32(intren_reg);
  85        /* Is interrupt enabled and active ? */
  86        if (!(val & intr_mask) && (ioread32(intrstat_reg) & HIPIR_NOPEND))
  87                return IRQ_NONE;
  88        /* Disable interrupt */
  89        iowrite32(intr_bit, intrdis_reg);
  90        return IRQ_HANDLED;
  91}
  92
  93static void pruss_cleanup(struct platform_device *dev,
  94                        struct uio_pruss_dev *gdev)
  95{
  96        int cnt;
  97        struct uio_info *p = gdev->info;
  98
  99        for (cnt = 0; cnt < MAX_PRUSS_EVT; cnt++, p++) {
 100                uio_unregister_device(p);
 101                kfree(p->name);
 102        }
 103        iounmap(gdev->prussio_vaddr);
 104        if (gdev->ddr_vaddr) {
 105                dma_free_coherent(&dev->dev, extram_pool_sz, gdev->ddr_vaddr,
 106                        gdev->ddr_paddr);
 107        }
 108        if (gdev->sram_vaddr)
 109                sram_free(gdev->sram_vaddr, sram_pool_sz);
 110        kfree(gdev->info);
 111        clk_put(gdev->pruss_clk);
 112        kfree(gdev);
 113}
 114
 115static int __devinit pruss_probe(struct platform_device *dev)
 116{
 117        struct uio_info *p;
 118        struct uio_pruss_dev *gdev;
 119        struct resource *regs_prussio;
 120        int ret = -ENODEV, cnt = 0, len;
 121        struct uio_pruss_pdata *pdata = dev->dev.platform_data;
 122
 123        gdev = kzalloc(sizeof(struct uio_pruss_dev), GFP_KERNEL);
 124        if (!gdev)
 125                return -ENOMEM;
 126
 127        gdev->info = kzalloc(sizeof(*p) * MAX_PRUSS_EVT, GFP_KERNEL);
 128        if (!gdev->info) {
 129                kfree(gdev);
 130                return -ENOMEM;
 131        }
 132        /* Power on PRU in case its not done as part of boot-loader */
 133        gdev->pruss_clk = clk_get(&dev->dev, "pruss");
 134        if (IS_ERR(gdev->pruss_clk)) {
 135                dev_err(&dev->dev, "Failed to get clock\n");
 136                kfree(gdev->info);
 137                kfree(gdev);
 138                ret = PTR_ERR(gdev->pruss_clk);
 139                return ret;
 140        } else {
 141                clk_enable(gdev->pruss_clk);
 142        }
 143
 144        regs_prussio = platform_get_resource(dev, IORESOURCE_MEM, 0);
 145        if (!regs_prussio) {
 146                dev_err(&dev->dev, "No PRUSS I/O resource specified\n");
 147                goto out_free;
 148        }
 149
 150        if (!regs_prussio->start) {
 151                dev_err(&dev->dev, "Invalid memory resource\n");
 152                goto out_free;
 153        }
 154
 155        gdev->sram_vaddr = sram_alloc(sram_pool_sz, &(gdev->sram_paddr));
 156        if (!gdev->sram_vaddr) {
 157                dev_err(&dev->dev, "Could not allocate SRAM pool\n");
 158                goto out_free;
 159        }
 160
 161        gdev->ddr_vaddr = dma_alloc_coherent(&dev->dev, extram_pool_sz,
 162                                &(gdev->ddr_paddr), GFP_KERNEL | GFP_DMA);
 163        if (!gdev->ddr_vaddr) {
 164                dev_err(&dev->dev, "Could not allocate external memory\n");
 165                goto out_free;
 166        }
 167
 168        len = resource_size(regs_prussio);
 169        gdev->prussio_vaddr = ioremap(regs_prussio->start, len);
 170        if (!gdev->prussio_vaddr) {
 171                dev_err(&dev->dev, "Can't remap PRUSS I/O  address range\n");
 172                goto out_free;
 173        }
 174
 175        gdev->pintc_base = pdata->pintc_base;
 176        gdev->hostirq_start = platform_get_irq(dev, 0);
 177
 178        for (cnt = 0, p = gdev->info; cnt < MAX_PRUSS_EVT; cnt++, p++) {
 179                p->mem[0].addr = regs_prussio->start;
 180                p->mem[0].size = resource_size(regs_prussio);
 181                p->mem[0].memtype = UIO_MEM_PHYS;
 182
 183                p->mem[1].addr = gdev->sram_paddr;
 184                p->mem[1].size = sram_pool_sz;
 185                p->mem[1].memtype = UIO_MEM_PHYS;
 186
 187                p->mem[2].addr = gdev->ddr_paddr;
 188                p->mem[2].size = extram_pool_sz;
 189                p->mem[2].memtype = UIO_MEM_PHYS;
 190
 191                p->name = kasprintf(GFP_KERNEL, "pruss_evt%d", cnt);
 192                p->version = DRV_VERSION;
 193
 194                /* Register PRUSS IRQ lines */
 195                p->irq = gdev->hostirq_start + cnt;
 196                p->handler = pruss_handler;
 197                p->priv = gdev;
 198
 199                ret = uio_register_device(&dev->dev, p);
 200                if (ret < 0)
 201                        goto out_free;
 202        }
 203
 204        platform_set_drvdata(dev, gdev);
 205        return 0;
 206
 207out_free:
 208        pruss_cleanup(dev, gdev);
 209        return ret;
 210}
 211
 212static int __devexit pruss_remove(struct platform_device *dev)
 213{
 214        struct uio_pruss_dev *gdev = platform_get_drvdata(dev);
 215
 216        pruss_cleanup(dev, gdev);
 217        platform_set_drvdata(dev, NULL);
 218        return 0;
 219}
 220
 221static struct platform_driver pruss_driver = {
 222        .probe = pruss_probe,
 223        .remove = __devexit_p(pruss_remove),
 224        .driver = {
 225                   .name = DRV_NAME,
 226                   .owner = THIS_MODULE,
 227                   },
 228};
 229
 230module_platform_driver(pruss_driver);
 231
 232MODULE_LICENSE("GPL v2");
 233MODULE_VERSION(DRV_VERSION);
 234MODULE_AUTHOR("Amit Chatterjee <amit.chatterjee@ti.com>");
 235MODULE_AUTHOR("Pratheesh Gangadhar <pratheesh@ti.com>");
 236
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