drivers/uio/uio_pruss.c

   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
  33 static int sram_pool_sz = SZ_16K;
  34 module_param(sram_pool_sz, int, 0);
  35 MODULE_PARM_DESC(sram_pool_sz, "sram pool size to allocate ");
  36
  37 static int extram_pool_sz = SZ_256K;
  38 module_param(extram_pool_sz, int, 0);
  39 MODULE_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
  62 struct 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
  75 static 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
  94 static 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
 118 static 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_get_platdata(&dev->dev);
 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                 ret = PTR_ERR(gdev->pruss_clk);
 140                 kfree(gdev->info);
 141                 kfree(gdev);
 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
 217 out_free:
 218         pruss_cleanup(dev, gdev);
 219         return ret;
 220 }
 221
 222 static 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         return 0;
 228 }
 229
 230 static struct platform_driver pruss_driver = {
 231         .probe = pruss_probe,
 232         .remove = pruss_remove,
 233         .driver = {
 234                    .name = DRV_NAME,
 235                    .owner = THIS_MODULE,
 236                    },
 237 };
 238
 239 module_platform_driver(pruss_driver);
 240
 241 MODULE_LICENSE("GPL v2");
 242 MODULE_VERSION(DRV_VERSION);
 243 MODULE_AUTHOR("Amit Chatterjee <amit.chatterjee@ti.com>");
 244 MODULE_AUTHOR("Pratheesh Gangadhar <pratheesh@ti.com>");