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 <linux/genalloc.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        unsigned long sram_vaddr;
  69        void *ddr_vaddr;
  70        unsigned int hostirq_start;
  71        unsigned int pintc_base;
  72        struct gen_pool *sram_pool;
  73};
  74
  75static irqreturn_t pruss_handler(int irq, struct uio_info *info)
  76{
  77        struct uio_pruss_dev *gdev = info->priv;
  78        int intr_bit = (irq - gdev->hostirq_start + 2);
  79        int val, intr_mask = (1 << intr_bit);
  80        void __iomem *base = gdev->prussio_vaddr + gdev->pintc_base;
  81        void __iomem *intren_reg = base + PINTC_HIER;
  82        void __iomem *intrdis_reg = base + PINTC_HIDISR;
  83        void __iomem *intrstat_reg = base + PINTC_HIPIR + (intr_bit << 2);
  84
  85        val = ioread32(intren_reg);
  86        /* Is interrupt enabled and active ? */
  87        if (!(val & intr_mask) && (ioread32(intrstat_reg) & HIPIR_NOPEND))
  88                return IRQ_NONE;
  89        /* Disable interrupt */
  90        iowrite32(intr_bit, intrdis_reg);
  91        return IRQ_HANDLED;
  92}
  93
  94static void pruss_cleanup(struct platform_device *dev,
  95                        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->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_put(gdev->pruss_clk);
 115        kfree(gdev);
 116}
 117
 118static int pruss_probe(struct platform_device *dev)
 119{
 120        struct uio_info *p;
 121        struct uio_pruss_dev *gdev;
 122        struct resource *regs_prussio;
 123        int ret = -ENODEV, cnt = 0, len;
 124        struct uio_pruss_pdata *pdata = dev->dev.platform_data;
 125
 126        gdev = kzalloc(sizeof(struct uio_pruss_dev), GFP_KERNEL);
 127        if (!gdev)
 128                return -ENOMEM;
 129
 130        gdev->info = kzalloc(sizeof(*p) * MAX_PRUSS_EVT, GFP_KERNEL);
 131        if (!gdev->info) {
 132                kfree(gdev);
 133                return -ENOMEM;
 134        }
 135        /* Power on PRU in case its not done as part of boot-loader */
 136        gdev->pruss_clk = clk_get(&dev->dev, "pruss");
 137        if (IS_ERR(gdev->pruss_clk)) {
 138                dev_err(&dev->dev, "Failed to get clock\n");
 139                kfree(gdev->info);
 140                kfree(gdev);
 141                ret = PTR_ERR(gdev->pruss_clk);
 142                return ret;
 143        } else {
 144                clk_enable(gdev->pruss_clk);
 145        }
 146
 147        regs_prussio = platform_get_resource(dev, IORESOURCE_MEM, 0);
 148        if (!regs_prussio) {
 149                dev_err(&dev->dev, "No PRUSS I/O resource specified\n");
 150                goto out_free;
 151        }
 152
 153        if (!regs_prussio->start) {
 154                dev_err(&dev->dev, "Invalid memory resource\n");
 155                goto out_free;
 156        }
 157
 158        if (pdata->sram_pool) {
 159                gdev->sram_pool = pdata->sram_pool;
 160                gdev->sram_vaddr =
 161                        gen_pool_alloc(gdev->sram_pool, sram_pool_sz);
 162                if (!gdev->sram_vaddr) {
 163                        dev_err(&dev->dev, "Could not allocate SRAM pool\n");
 164                        goto out_free;
 165                }
 166                gdev->sram_paddr =
 167                        gen_pool_virt_to_phys(gdev->sram_pool,
 168                                              gdev->sram_vaddr);
 169        }
 170
 171        gdev->ddr_vaddr = dma_alloc_coherent(&dev->dev, extram_pool_sz,
 172                                &(gdev->ddr_paddr), GFP_KERNEL | GFP_DMA);
 173        if (!gdev->ddr_vaddr) {
 174                dev_err(&dev->dev, "Could not allocate external memory\n");
 175                goto out_free;
 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->dev, "Can't remap PRUSS I/O  address range\n");
 182                goto out_free;
 183        }
 184
 185        gdev->pintc_base = pdata->pintc_base;
 186        gdev->hostirq_start = platform_get_irq(dev, 0);
 187
 188        for (cnt = 0, p = gdev->info; cnt < MAX_PRUSS_EVT; cnt++, p++) {
 189                p->mem[0].addr = regs_prussio->start;
 190                p->mem[0].size = resource_size(regs_prussio);
 191                p->mem[0].memtype = UIO_MEM_PHYS;
 192
 193                p->mem[1].addr = gdev->sram_paddr;
 194                p->mem[1].size = sram_pool_sz;
 195                p->mem[1].memtype = UIO_MEM_PHYS;
 196
 197                p->mem[2].addr = gdev->ddr_paddr;
 198                p->mem[2].size = extram_pool_sz;
 199                p->mem[2].memtype = UIO_MEM_PHYS;
 200
 201                p->name = kasprintf(GFP_KERNEL, "pruss_evt%d", cnt);
 202                p->version = DRV_VERSION;
 203
 204                /* Register PRUSS IRQ lines */
 205                p->irq = gdev->hostirq_start + cnt;
 206                p->handler = pruss_handler;
 207                p->priv = gdev;
 208
 209                ret = uio_register_device(&dev->dev, p);
 210                if (ret < 0)
 211                        goto out_free;
 212        }
 213
 214        platform_set_drvdata(dev, gdev);
 215        return 0;
 216
 217out_free:
 218        pruss_cleanup(dev, gdev);
 219        return ret;
 220}
 221
 222static int pruss_remove(struct platform_device *dev)
 223{
 224        struct uio_pruss_dev *gdev = platform_get_drvdata(dev);
 225
 226        pruss_cleanup(dev, gdev);
 227        platform_set_drvdata(dev, NULL);
 228        return 0;
 229}
 230
 231static struct platform_driver pruss_driver = {
 232        .probe = pruss_probe,
 233        .remove = pruss_remove,
 234        .driver = {
 235                   .name = DRV_NAME,
 236                   .owner = THIS_MODULE,
 237                   },
 238};
 239
 240module_platform_driver(pruss_driver);
 241
 242MODULE_LICENSE("GPL v2");
 243MODULE_VERSION(DRV_VERSION);
 244MODULE_AUTHOR("Amit Chatterjee <amit.chatterjee@ti.com>");
 245MODULE_AUTHOR("Pratheesh Gangadhar <pratheesh@ti.com>");
 246
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