LXR linux/drivers/uio/uio

   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/sizes.h>
  28#include <linux/slab.h>
  29#include <linux/genalloc.h>
  30
  31#define DRV_NAME "pruss_uio"
  32#define DRV_VERSION "1.0"
  33
  34static int sram_pool_sz = SZ_16K;
  35module_param(sram_pool_sz, int, 0);
  36MODULE_PARM_DESC(sram_pool_sz, "sram pool size to allocate ");
  37
  38static int extram_pool_sz = SZ_256K;
  39module_param(extram_pool_sz, int, 0);
  40MODULE_PARM_DESC(extram_pool_sz, "external ram pool size to allocate");
  41
  42/*
  43 * Host event IRQ numbers from PRUSS - PRUSS can generate up to 8 interrupt
  44 * events to AINTC of ARM host processor - which can be used for IPC b/w PRUSS
  45 * firmware and user space application, async notification from PRU firmware
  46 * to user space application
  47 * 3    PRU_EVTOUT0
  48 * 4    PRU_EVTOUT1
  49 * 5    PRU_EVTOUT2
  50 * 6    PRU_EVTOUT3
  51 * 7    PRU_EVTOUT4
  52 * 8    PRU_EVTOUT5
  53 * 9    PRU_EVTOUT6
  54 * 10   PRU_EVTOUT7
  55*/
  56#define MAX_PRUSS_EVT   8
  57
  58#define PINTC_HIDISR    0x0038
  59#define PINTC_HIPIR     0x0900
  60#define HIPIR_NOPEND    0x80000000
  61#define PINTC_HIER      0x1500
  62
  63struct uio_pruss_dev {
  64        struct uio_info *info;
  65        struct clk *pruss_clk;
  66        dma_addr_t sram_paddr;
  67        dma_addr_t ddr_paddr;
  68        void __iomem *prussio_vaddr;
  69        unsigned long sram_vaddr;
  70        void *ddr_vaddr;
  71        unsigned int hostirq_start;
  72        unsigned int pintc_base;
  73        struct gen_pool *sram_pool;
  74};
  75
  76static irqreturn_t pruss_handler(int irq, struct uio_info *info)
  77{
  78        struct uio_pruss_dev *gdev = info->priv;
  79        int intr_bit = (irq - gdev->hostirq_start + 2);
  80        int val, intr_mask = (1 << intr_bit);
  81        void __iomem *base = gdev->prussio_vaddr + gdev->pintc_base;
  82        void __iomem *intren_reg = base + PINTC_HIER;
  83        void __iomem *intrdis_reg = base + PINTC_HIDISR;
  84        void __iomem *intrstat_reg = base + PINTC_HIPIR + (intr_bit << 2);
  85
  86        val = ioread32(intren_reg);
  87        /* Is interrupt enabled and active ? */
  88        if (!(val & intr_mask) && (ioread32(intrstat_reg) & HIPIR_NOPEND))
  89                return IRQ_NONE;
  90        /* Disable interrupt */
  91        iowrite32(intr_bit, intrdis_reg);
  92        return IRQ_HANDLED;
  93}
  94
  95static void pruss_cleanup(struct device *dev, struct uio_pruss_dev *gdev)
  96{
  97        int cnt;
  98        struct uio_info *p = gdev->info;
  99
 100        for (cnt = 0; cnt < MAX_PRUSS_EVT; cnt++, p++) {
 101                uio_unregister_device(p);
 102        }
 103        iounmap(gdev->prussio_vaddr);
 104        if (gdev->ddr_vaddr) {
 105                dma_free_coherent(dev, extram_pool_sz, gdev->ddr_vaddr,
 106                        gdev->ddr_paddr);
 107        }
 108        if (gdev->sram_vaddr)
 109                gen_pool_free(gdev->sram_pool,
 110                              gdev->sram_vaddr,
 111                              sram_pool_sz);
 112        clk_disable(gdev->pruss_clk);
 113}
 114
 115static int pruss_probe(struct platform_device *pdev)
 116{
 117        struct uio_info *p;
 118        struct uio_pruss_dev *gdev;
 119        struct resource *regs_prussio;
 120        struct device *dev = &pdev->dev;
 121        int ret, cnt, i, len;
 122        struct uio_pruss_pdata *pdata = dev_get_platdata(dev);
 123
 124        gdev = devm_kzalloc(dev, sizeof(struct uio_pruss_dev), GFP_KERNEL);
 125        if (!gdev)
 126                return -ENOMEM;
 127
 128        gdev->info = devm_kcalloc(dev, MAX_PRUSS_EVT, sizeof(*p), GFP_KERNEL);
 129        if (!gdev->info)
 130                return -ENOMEM;
 131
 132        /* Power on PRU in case its not done as part of boot-loader */
 133        gdev->pruss_clk = devm_clk_get(dev, "pruss");
 134        if (IS_ERR(gdev->pruss_clk)) {
 135                dev_err(dev, "Failed to get clock\n");
 136                return PTR_ERR(gdev->pruss_clk);
 137        }
 138
 139        ret = clk_enable(gdev->pruss_clk);
 140        if (ret) {
 141                dev_err(dev, "Failed to enable clock\n");
 142                return ret;
 143        }
 144
 145        regs_prussio = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 146        if (!regs_prussio) {
 147                dev_err(dev, "No PRUSS I/O resource specified\n");
 148                ret = -EIO;
 149                goto err_clk_disable;
 150        }
 151
 152        if (!regs_prussio->start) {
 153                dev_err(dev, "Invalid memory resource\n");
 154                ret = -EIO;
 155                goto err_clk_disable;
 156        }
 157
 158        if (pdata->sram_pool) {
 159                gdev->sram_pool = pdata->sram_pool;
 160                gdev->sram_vaddr =
 161                        (unsigned long)gen_pool_dma_alloc(gdev->sram_pool,
 162                                        sram_pool_sz, &gdev->sram_paddr);
 163                if (!gdev->sram_vaddr) {
 164                        dev_err(dev, "Could not allocate SRAM pool\n");
 165                        ret = -ENOMEM;
 166                        goto err_clk_disable;
 167                }
 168        }
 169
 170        gdev->ddr_vaddr = dma_alloc_coherent(dev, extram_pool_sz,
 171                                &(gdev->ddr_paddr), GFP_KERNEL | GFP_DMA);
 172        if (!gdev->ddr_vaddr) {
 173                dev_err(dev, "Could not allocate external memory\n");
 174                ret = -ENOMEM;
 175                goto err_free_sram;
 176        }
 177
 178        len = resource_size(regs_prussio);
 179        gdev->prussio_vaddr = ioremap(regs_prussio->start, len);
 180        if (!gdev->prussio_vaddr) {
 181                dev_err(dev, "Can't remap PRUSS I/O  address range\n");
 182                ret = -ENOMEM;
 183                goto err_free_ddr_vaddr;
 184        }
 185
 186        gdev->pintc_base = pdata->pintc_base;
 187        gdev->hostirq_start = platform_get_irq(pdev, 0);
 188
 189        for (cnt = 0, p = gdev->info; cnt < MAX_PRUSS_EVT; cnt++, p++) {
 190                p->mem[0].addr = regs_prussio->start;
 191                p->mem[0].size = resource_size(regs_prussio);
 192                p->mem[0].memtype = UIO_MEM_PHYS;
 193
 194                p->mem[1].addr = gdev->sram_paddr;
 195                p->mem[1].size = sram_pool_sz;
 196                p->mem[1].memtype = UIO_MEM_PHYS;
 197
 198                p->mem[2].addr = gdev->ddr_paddr;
 199                p->mem[2].size = extram_pool_sz;
 200                p->mem[2].memtype = UIO_MEM_PHYS;
 201
 202                p->name = devm_kasprintf(dev, GFP_KERNEL, "pruss_evt%d", cnt);
 203                p->version = DRV_VERSION;
 204
 205                /* Register PRUSS IRQ lines */
 206                p->irq = gdev->hostirq_start + cnt;
 207                p->handler = pruss_handler;
 208                p->priv = gdev;
 209
 210                ret = uio_register_device(dev, p);
 211                if (ret < 0)
 212                        goto err_unloop;
 213        }
 214
 215        platform_set_drvdata(pdev, gdev);
 216        return 0;
 217
 218err_unloop:
 219        for (i = 0, p = gdev->info; i < cnt; i++, p++) {
 220                uio_unregister_device(p);
 221        }
 222        iounmap(gdev->prussio_vaddr);
 223err_free_ddr_vaddr:
 224        dma_free_coherent(dev, extram_pool_sz, gdev->ddr_vaddr,
 225                          gdev->ddr_paddr);
 226err_free_sram:
 227        if (pdata->sram_pool)
 228                gen_pool_free(gdev->sram_pool, gdev->sram_vaddr, sram_pool_sz);
 229err_clk_disable:
 230        clk_disable(gdev->pruss_clk);
 231
 232        return ret;
 233}
 234
 235static int pruss_remove(struct platform_device *dev)
 236{
 237        struct uio_pruss_dev *gdev = platform_get_drvdata(dev);
 238
 239        pruss_cleanup(&dev->dev, gdev);
 240        return 0;
 241}
 242
 243static struct platform_driver pruss_driver = {
 244        .probe = pruss_probe,
 245        .remove = pruss_remove,
 246        .driver = {
 247                   .name = DRV_NAME,
 248                   },
 249};
 250
 251module_platform_driver(pruss_driver);
 252
 253MODULE_LICENSE("GPL v2");
 254MODULE_VERSION(DRV_VERSION);
 255MODULE_AUTHOR("Amit Chatterjee <amit.chatterjee@ti.com>");
 256MODULE_AUTHOR("Pratheesh Gangadhar <pratheesh@ti.com>");
 257