linux-imx

/*

 * Programmable Real-Time Unit Sub System (PRUSS) UIO driver (uio_pruss)

 *

 * This driver exports PRUSS host event out interrupts and PRUSS, L3 RAM,

 * and DDR RAM to user space for applications interacting with PRUSS firmware

 *

 * Copyright (C) 2010-11 Texas Instruments Incorporated - http://www.ti.com/

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License as

 * published by the Free Software Foundation version 2.

 *

 * This program is distributed "as is" WITHOUT ANY WARRANTY of any

 * kind, whether express or implied; without even the implied warranty

 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 */

#include <linux/device.h>

#include <linux/module.h>

#include <linux/moduleparam.h>

#include <linux/platform_device.h>

#include <linux/uio_driver.h>

#include <linux/platform_data/uio_pruss.h>

#include <linux/io.h>

#include <linux/clk.h>

#include <linux/dma-mapping.h>

#include <linux/sizes.h>

#include <linux/slab.h>

#include <linux/genalloc.h>

​

#define DRV_NAME "pruss_uio"

#define DRV_VERSION "1.0"

​

static int sram_pool_sz = SZ_16K;

module_param(sram_pool_sz, int, 0);

MODULE_PARM_DESC(sram_pool_sz, "sram pool size to allocate ");

​

static int extram_pool_sz = SZ_256K;

module_param(extram_pool_sz, int, 0);

MODULE_PARM_DESC(extram_pool_sz, "external ram pool size to allocate");

​

/*

 * Host event IRQ numbers from PRUSS - PRUSS can generate up to 8 interrupt

 * events to AINTC of ARM host processor - which can be used for IPC b/w PRUSS

 * firmware and user space application, async notification from PRU firmware

 * to user space application

 * 3    PRU_EVTOUT0

 * 4    PRU_EVTOUT1

 * 5    PRU_EVTOUT2

 * 6    PRU_EVTOUT3

 * 7    PRU_EVTOUT4

 * 8    PRU_EVTOUT5

 * 9    PRU_EVTOUT6

 * 10   PRU_EVTOUT7

*/

#define MAX_PRUSS_EVT   8

​

#define PINTC_HIDISR    0x0038

#define PINTC_HIPIR 0x0900

#define HIPIR_NOPEND    0x80000000

#define PINTC_HIER  0x1500

​

struct uio_pruss_dev {

    struct uio_info *info;

    struct clk *pruss_clk;

    dma_addr_t sram_paddr;

    dma_addr_t ddr_paddr;

    void __iomem *prussio_vaddr;

    unsigned long sram_vaddr;

    void *ddr_vaddr;

    unsigned int hostirq_start;

    unsigned int pintc_base;

    struct gen_pool *sram_pool;

};

​

static irqreturn_t pruss_handler(int irq, struct uio_info *info)

{

    struct uio_pruss_dev *gdev = info->priv;

    int intr_bit = (irq - gdev->hostirq_start + 2);

    int val, intr_mask = (1 << intr_bit);

    void __iomem *base = gdev->prussio_vaddr + gdev->pintc_base;

    void __iomem *intren_reg = base + PINTC_HIER;

    void __iomem *intrdis_reg = base + PINTC_HIDISR;

    void __iomem *intrstat_reg = base + PINTC_HIPIR + (intr_bit << 2);

​

    val = ioread32(intren_reg);

    /* Is interrupt enabled and active ? */

    if (!(val & intr_mask) && (ioread32(intrstat_reg) & HIPIR_NOPEND))

        return IRQ_NONE;

    /* Disable interrupt */

    iowrite32(intr_bit, intrdis_reg);

    return IRQ_HANDLED;