drivers/uio/uio_pruss.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Programmable Real-Time Unit Sub System (PRUSS) UIO driver (uio_pruss)
0004  *
0005  * This driver exports PRUSS host event out interrupts and PRUSS, L3 RAM,
0006  * and DDR RAM to user space for applications interacting with PRUSS firmware
0007  *
0008  * Copyright (C) 2010-11 Texas Instruments Incorporated - http://www.ti.com/
0009  */
0010 #include <linux/device.h>
0011 #include <linux/module.h>
0012 #include <linux/moduleparam.h>
0013 #include <linux/platform_device.h>
0014 #include <linux/uio_driver.h>
0015 #include <linux/platform_data/uio_pruss.h>
0016 #include <linux/io.h>
0017 #include <linux/clk.h>
0018 #include <linux/dma-mapping.h>
0019 #include <linux/sizes.h>
0020 #include <linux/slab.h>
0021 #include <linux/genalloc.h>
0022
0023 #define DRV_NAME "pruss_uio"
0024 #define DRV_VERSION "1.0"
0025
0026 static int sram_pool_sz = SZ_16K;
0027 module_param(sram_pool_sz, int, 0);
0028 MODULE_PARM_DESC(sram_pool_sz, "sram pool size to allocate ");
0029
0030 static int extram_pool_sz = SZ_256K;
0031 module_param(extram_pool_sz, int, 0);
0032 MODULE_PARM_DESC(extram_pool_sz, "external ram pool size to allocate");
0033
0034 /*
0035  * Host event IRQ numbers from PRUSS - PRUSS can generate up to 8 interrupt
0036  * events to AINTC of ARM host processor - which can be used for IPC b/w PRUSS
0037  * firmware and user space application, async notification from PRU firmware
0038  * to user space application
0039  * 3    PRU_EVTOUT0
0040  * 4    PRU_EVTOUT1
0041  * 5    PRU_EVTOUT2
0042  * 6    PRU_EVTOUT3
0043  * 7    PRU_EVTOUT4
0044  * 8    PRU_EVTOUT5
0045  * 9    PRU_EVTOUT6
0046  * 10   PRU_EVTOUT7
0047 */
0048 #define MAX_PRUSS_EVT   8
0049
0050 #define PINTC_HIDISR    0x0038
0051 #define PINTC_HIPIR 0x0900
0052 #define HIPIR_NOPEND    0x80000000
0053 #define PINTC_HIER  0x1500
0054
0055 struct uio_pruss_dev {
0056     struct uio_info *info;
0057     struct clk *pruss_clk;
0058     dma_addr_t sram_paddr;
0059     dma_addr_t ddr_paddr;
0060     void __iomem *prussio_vaddr;
0061     unsigned long sram_vaddr;
0062     void *ddr_vaddr;
0063     unsigned int hostirq_start;
0064     unsigned int pintc_base;
0065     struct gen_pool *sram_pool;
0066 };
0067
0068 static irqreturn_t pruss_handler(int irq, struct uio_info *info)
0069 {
0070     struct uio_pruss_dev *gdev = info->priv;
0071     int intr_bit = (irq - gdev->hostirq_start + 2);
0072     int val, intr_mask = (1 << intr_bit);
0073     void __iomem *base = gdev->prussio_vaddr + gdev->pintc_base;
0074     void __iomem *intren_reg = base + PINTC_HIER;
0075     void __iomem *intrdis_reg = base + PINTC_HIDISR;
0076     void __iomem *intrstat_reg = base + PINTC_HIPIR + (intr_bit << 2);
0077
0078     val = ioread32(intren_reg);
0079     /* Is interrupt enabled and active ? */
0080     if (!(val & intr_mask) && (ioread32(intrstat_reg) & HIPIR_NOPEND))
0081         return IRQ_NONE;
0082     /* Disable interrupt */
0083     iowrite32(intr_bit, intrdis_reg);
0084     return IRQ_HANDLED;
0085 }
0086
0087 static void pruss_cleanup(struct device *dev, struct uio_pruss_dev *gdev)
0088 {
0089     int cnt;
0090     struct uio_info *p = gdev->info;
0091
0092     for (cnt = 0; cnt < MAX_PRUSS_EVT; cnt++, p++) {
0093         uio_unregister_device(p);
0094     }
0095     iounmap(gdev->prussio_vaddr);
0096     if (gdev->ddr_vaddr) {
0097         dma_free_coherent(dev, extram_pool_sz, gdev->ddr_vaddr,
0098             gdev->ddr_paddr);
0099     }
0100     if (gdev->sram_vaddr)
0101         gen_pool_free(gdev->sram_pool,
0102                   gdev->sram_vaddr,
0103                   sram_pool_sz);
0104     clk_disable(gdev->pruss_clk);
0105 }
0106
0107 static int pruss_probe(struct platform_device *pdev)
0108 {
0109     struct uio_info *p;
0110     struct uio_pruss_dev *gdev;
0111     struct resource *regs_prussio;
0112     struct device *dev = &pdev->dev;
0113     int ret, cnt, i, len;
0114     struct uio_pruss_pdata *pdata = dev_get_platdata(dev);
0115
0116     gdev = devm_kzalloc(dev, sizeof(struct uio_pruss_dev), GFP_KERNEL);
0117     if (!gdev)
0118         return -ENOMEM;
0119
0120     gdev->info = devm_kcalloc(dev, MAX_PRUSS_EVT, sizeof(*p), GFP_KERNEL);
0121     if (!gdev->info)
0122         return -ENOMEM;
0123
0124     /* Power on PRU in case its not done as part of boot-loader */
0125     gdev->pruss_clk = devm_clk_get(dev, "pruss");
0126     if (IS_ERR(gdev->pruss_clk)) {
0127         dev_err(dev, "Failed to get clock\n");
0128         return PTR_ERR(gdev->pruss_clk);
0129     }
0130
0131     ret = clk_enable(gdev->pruss_clk);
0132     if (ret) {
0133         dev_err(dev, "Failed to enable clock\n");
0134         return ret;
0135     }
0136
0137     regs_prussio = platform_get_resource(pdev, IORESOURCE_MEM, 0);
0138     if (!regs_prussio) {
0139         dev_err(dev, "No PRUSS I/O resource specified\n");
0140         ret = -EIO;
0141         goto err_clk_disable;
0142     }
0143
0144     if (!regs_prussio->start) {
0145         dev_err(dev, "Invalid memory resource\n");
0146         ret = -EIO;
0147         goto err_clk_disable;
0148     }
0149
0150     if (pdata->sram_pool) {
0151         gdev->sram_pool = pdata->sram_pool;
0152         gdev->sram_vaddr =
0153             (unsigned long)gen_pool_dma_alloc(gdev->sram_pool,
0154                     sram_pool_sz, &gdev->sram_paddr);
0155         if (!gdev->sram_vaddr) {
0156             dev_err(dev, "Could not allocate SRAM pool\n");
0157             ret = -ENOMEM;
0158             goto err_clk_disable;
0159         }
0160     }
0161
0162     gdev->ddr_vaddr = dma_alloc_coherent(dev, extram_pool_sz,
0163                 &(gdev->ddr_paddr), GFP_KERNEL | GFP_DMA);
0164     if (!gdev->ddr_vaddr) {
0165         dev_err(dev, "Could not allocate external memory\n");
0166         ret = -ENOMEM;
0167         goto err_free_sram;
0168     }
0169
0170     len = resource_size(regs_prussio);
0171     gdev->prussio_vaddr = ioremap(regs_prussio->start, len);
0172     if (!gdev->prussio_vaddr) {
0173         dev_err(dev, "Can't remap PRUSS I/O  address range\n");
0174         ret = -ENOMEM;
0175         goto err_free_ddr_vaddr;
0176     }
0177
0178     gdev->pintc_base = pdata->pintc_base;
0179     gdev->hostirq_start = platform_get_irq(pdev, 0);
0180
0181     for (cnt = 0, p = gdev->info; cnt < MAX_PRUSS_EVT; cnt++, p++) {
0182         p->mem[0].addr = regs_prussio->start;
0183         p->mem[0].size = resource_size(regs_prussio);
0184         p->mem[0].memtype = UIO_MEM_PHYS;
0185
0186         p->mem[1].addr = gdev->sram_paddr;
0187         p->mem[1].size = sram_pool_sz;
0188         p->mem[1].memtype = UIO_MEM_PHYS;
0189
0190         p->mem[2].addr = gdev->ddr_paddr;
0191         p->mem[2].size = extram_pool_sz;
0192         p->mem[2].memtype = UIO_MEM_PHYS;
0193
0194         p->name = devm_kasprintf(dev, GFP_KERNEL, "pruss_evt%d", cnt);
0195         p->version = DRV_VERSION;
0196
0197         /* Register PRUSS IRQ lines */
0198         p->irq = gdev->hostirq_start + cnt;
0199         p->handler = pruss_handler;
0200         p->priv = gdev;
0201
0202         ret = uio_register_device(dev, p);
0203         if (ret < 0)
0204             goto err_unloop;
0205     }
0206
0207     platform_set_drvdata(pdev, gdev);
0208     return 0;
0209
0210 err_unloop:
0211     for (i = 0, p = gdev->info; i < cnt; i++, p++) {
0212         uio_unregister_device(p);
0213     }
0214     iounmap(gdev->prussio_vaddr);
0215 err_free_ddr_vaddr:
0216     dma_free_coherent(dev, extram_pool_sz, gdev->ddr_vaddr,
0217               gdev->ddr_paddr);
0218 err_free_sram:
0219     if (pdata->sram_pool)
0220         gen_pool_free(gdev->sram_pool, gdev->sram_vaddr, sram_pool_sz);
0221 err_clk_disable:
0222     clk_disable(gdev->pruss_clk);
0223
0224     return ret;
0225 }
0226
0227 static int pruss_remove(struct platform_device *dev)
0228 {
0229     struct uio_pruss_dev *gdev = platform_get_drvdata(dev);
0230
0231     pruss_cleanup(&dev->dev, gdev);
0232     return 0;
0233 }
0234
0235 static struct platform_driver pruss_driver = {
0236     .probe = pruss_probe,
0237     .remove = pruss_remove,
0238     .driver = {
0239            .name = DRV_NAME,
0240            },
0241 };
0242
0243 module_platform_driver(pruss_driver);
0244
0245 MODULE_LICENSE("GPL v2");
0246 MODULE_VERSION(DRV_VERSION);
0247 MODULE_AUTHOR("Amit Chatterjee <amit.chatterjee@ti.com>");
0248 MODULE_AUTHOR("Pratheesh Gangadhar <pratheesh@ti.com>");