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/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                kfree(p->name);
 103        }
 104        iounmap(gdev->prussio_vaddr);
 105        if (gdev->ddr_vaddr) {
 106                dma_free_coherent(dev, extram_pool_sz, gdev->ddr_vaddr,
 107                        gdev->ddr_paddr);
 108        }
 109        if (gdev->sram_vaddr)
 110                gen_pool_free(gdev->sram_pool,
 111                              gdev->sram_vaddr,
 112                              sram_pool_sz);
 113        kfree(gdev->info);
 114        clk_disable(gdev->pruss_clk);
 115        clk_put(gdev->pruss_clk);
 116        kfree(gdev);
 117}
 118
 119static int pruss_probe(struct platform_device *pdev)
 120{
 121        struct uio_info *p;
 122        struct uio_pruss_dev *gdev;
 123        struct resource *regs_prussio;
 124        struct device *dev = &pdev->dev;
 125        int ret, cnt, i, len;
 126        struct uio_pruss_pdata *pdata = dev_get_platdata(dev);
 127
 128        gdev = kzalloc(sizeof(struct uio_pruss_dev), GFP_KERNEL);
 129        if (!gdev)
 130                return -ENOMEM;
 131
 132        gdev->info = kcalloc(MAX_PRUSS_EVT, sizeof(*p), GFP_KERNEL);
 133        if (!gdev->info) {
 134                ret = -ENOMEM;
 135                goto err_free_gdev;
 136        }
 137
 138        /* Power on PRU in case its not done as part of boot-loader */
 139        gdev->pruss_clk = clk_get(dev, "pruss");
 140        if (IS_ERR(gdev->pruss_clk)) {
 141                dev_err(dev, "Failed to get clock\n");
 142                ret = PTR_ERR(gdev->pruss_clk);
 143                goto err_free_info;
 144        }
 145
 146        ret = clk_enable(gdev->pruss_clk);
 147        if (ret) {
 148                dev_err(dev, "Failed to enable clock\n");
 149                goto err_clk_put;
 150        }
 151
 152        regs_prussio = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 153        if (!regs_prussio) {
 154                dev_err(dev, "No PRUSS I/O resource specified\n");
 155                ret = -EIO;
 156                goto err_clk_disable;
 157        }
 158
 159        if (!regs_prussio->start) {
 160                dev_err(dev, "Invalid memory resource\n");
 161                ret = -EIO;
 162                goto err_clk_disable;
 163        }
 164
 165        if (pdata->sram_pool) {
 166                gdev->sram_pool = pdata->sram_pool;
 167                gdev->sram_vaddr =
 168                        (unsigned long)gen_pool_dma_alloc(gdev->sram_pool,
 169                                        sram_pool_sz, &gdev->sram_paddr);
 170                if (!gdev->sram_vaddr) {
 171                        dev_err(dev, "Could not allocate SRAM pool\n");
 172                        ret = -ENOMEM;
 173                        goto err_clk_disable;
 174                }
 175        }
 176
 177        gdev->ddr_vaddr = dma_alloc_coherent(dev, extram_pool_sz,
 178                                &(gdev->ddr_paddr), GFP_KERNEL | GFP_DMA);
 179        if (!gdev->ddr_vaddr) {
 180                dev_err(dev, "Could not allocate external memory\n");
 181                ret = -ENOMEM;
 182                goto err_free_sram;
 183        }
 184
 185        len = resource_size(regs_prussio);
 186        gdev->prussio_vaddr = ioremap(regs_prussio->start, len);
 187        if (!gdev->prussio_vaddr) {
 188                dev_err(dev, "Can't remap PRUSS I/O  address range\n");
 189                ret = -ENOMEM;
 190                goto err_free_ddr_vaddr;
 191        }
 192
 193        gdev->pintc_base = pdata->pintc_base;
 194        gdev->hostirq_start = platform_get_irq(pdev, 0);
 195
 196        for (cnt = 0, p = gdev->info; cnt < MAX_PRUSS_EVT; cnt++, p++) {
 197                p->mem[0].addr = regs_prussio->start;
 198                p->mem[0].size = resource_size(regs_prussio);
 199                p->mem[0].memtype = UIO_MEM_PHYS;
 200
 201                p->mem[1].addr = gdev->sram_paddr;
 202                p->mem[1].size = sram_pool_sz;
 203                p->mem[1].memtype = UIO_MEM_PHYS;
 204
 205                p->mem[2].addr = gdev->ddr_paddr;
 206                p->mem[2].size = extram_pool_sz;
 207                p->mem[2].memtype = UIO_MEM_PHYS;
 208
 209                p->name = kasprintf(GFP_KERNEL, "pruss_evt%d", cnt);
 210                p->version = DRV_VERSION;
 211
 212                /* Register PRUSS IRQ lines */
 213                p->irq = gdev->hostirq_start + cnt;
 214                p->handler = pruss_handler;
 215                p->priv = gdev;
 216
 217                ret = uio_register_device(dev, p);
 218                if (ret < 0) {
 219                        kfree(p->name);
 220                        goto err_unloop;
 221                }
 222        }
 223
 224        platform_set_drvdata(pdev, gdev);
 225        return 0;
 226
 227err_unloop:
 228        for (i = 0, p = gdev->info; i < cnt; i++, p++) {
 229                uio_unregister_device(p);
 230                kfree(p->name);
 231        }
 232        iounmap(gdev->prussio_vaddr);
 233err_free_ddr_vaddr:
 234        dma_free_coherent(dev, extram_pool_sz, gdev->ddr_vaddr,
 235                          gdev->ddr_paddr);
 236err_free_sram:
 237        if (pdata->sram_pool)
 238                gen_pool_free(gdev->sram_pool, gdev->sram_vaddr, sram_pool_sz);
 239err_clk_disable:
 240        clk_disable(gdev->pruss_clk);
 241err_clk_put:
 242        clk_put(gdev->pruss_clk);
 243err_free_info:
 244        kfree(gdev->info);
 245err_free_gdev:
 246        kfree(gdev);
 247
 248        return ret;
 249}
 250
 251static int pruss_remove(struct platform_device *dev)
 252{
 253        struct uio_pruss_dev *gdev = platform_get_drvdata(dev);
 254
 255        pruss_cleanup(&dev->dev, gdev);
 256        return 0;
 257}
 258
 259static struct platform_driver pruss_driver = {
 260        .probe = pruss_probe,
 261        .remove = pruss_remove,
 262        .driver = {
 263                   .name = DRV_NAME,
 264                   },
 265};
 266
 267module_platform_driver(pruss_driver);
 268
 269MODULE_LICENSE("GPL v2");
 270MODULE_VERSION(DRV_VERSION);
 271MODULE_AUTHOR("Amit Chatterjee <amit.chatterjee@ti.com>");
 272MODULE_AUTHOR("Pratheesh Gangadhar <pratheesh@ti.com>");
 273