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/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
  34 static int sram_pool_sz = SZ_16K;
  35 module_param(sram_pool_sz, int, 0);
  36 MODULE_PARM_DESC(sram_pool_sz, "sram pool size to allocate ");
  37
  38 static int extram_pool_sz = SZ_256K;
  39 module_param(extram_pool_sz, int, 0);
  40 MODULE_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
  63 struct 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
  76 static 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
  95 static 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_put(gdev->pruss_clk);
 115         kfree(gdev);
 116 }
 117
 118 static int pruss_probe(struct platform_device *pdev)
 119 {
 120         struct uio_info *p;
 121         struct uio_pruss_dev *gdev;
 122         struct resource *regs_prussio;
 123         struct device *dev = &pdev->dev;
 124         int ret = -ENODEV, cnt = 0, len;
 125         struct uio_pruss_pdata *pdata = dev_get_platdata(dev);
 126
 127         gdev = kzalloc(sizeof(struct uio_pruss_dev), GFP_KERNEL);
 128         if (!gdev)
 129                 return -ENOMEM;
 130
 131         gdev->info = kzalloc(sizeof(*p) * MAX_PRUSS_EVT, GFP_KERNEL);
 132         if (!gdev->info) {
 133                 kfree(gdev);
 134                 return -ENOMEM;
 135         }
 136
 137         /* Power on PRU in case its not done as part of boot-loader */
 138         gdev->pruss_clk = clk_get(dev, "pruss");
 139         if (IS_ERR(gdev->pruss_clk)) {
 140                 dev_err(dev, "Failed to get clock\n");
 141                 ret = PTR_ERR(gdev->pruss_clk);
 142                 kfree(gdev->info);
 143                 kfree(gdev);
 144                 return ret;
 145         } else {
 146                 clk_enable(gdev->pruss_clk);
 147         }
 148
 149         regs_prussio = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 150         if (!regs_prussio) {
 151                 dev_err(dev, "No PRUSS I/O resource specified\n");
 152                 goto out_free;
 153         }
 154
 155         if (!regs_prussio->start) {
 156                 dev_err(dev, "Invalid memory resource\n");
 157                 goto out_free;
 158         }
 159
 160         if (pdata->sram_pool) {
 161                 gdev->sram_pool = pdata->sram_pool;
 162                 gdev->sram_vaddr =
 163                         (unsigned long)gen_pool_dma_alloc(gdev->sram_pool,
 164                                         sram_pool_sz, &gdev->sram_paddr);
 165                 if (!gdev->sram_vaddr) {
 166                         dev_err(dev, "Could not allocate SRAM pool\n");
 167                         goto out_free;
 168                 }
 169         }
 170
 171         gdev->ddr_vaddr = dma_alloc_coherent(dev, extram_pool_sz,
 172                                 &(gdev->ddr_paddr), GFP_KERNEL | GFP_DMA);
 173         if (!gdev->ddr_vaddr) {
 174                 dev_err(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, "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(pdev, 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, p);
 210                 if (ret < 0)
 211                         goto out_free;
 212         }
 213
 214         platform_set_drvdata(pdev, 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->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                    },
 236 };
 237
 238 module_platform_driver(pruss_driver);
 239
 240 MODULE_LICENSE("GPL v2");
 241 MODULE_VERSION(DRV_VERSION);
 242 MODULE_AUTHOR("Amit Chatterjee <amit.chatterjee@ti.com>");
 243 MODULE_AUTHOR("Pratheesh Gangadhar <pratheesh@ti.com>");