LXR linux/drivers/remoteproc/da8xx

   1/*
   2 * Remote processor machine-specific module for DA8XX
   3 *
   4 * Copyright (C) 2013 Texas Instruments, Inc.
   5 *
   6 * This program is free software; you can redistribute it and/or
   7 * modify it under the terms of the GNU General Public License
   8 * version 2 as published by the Free Software Foundation.
   9 */
  10
  11#include <linux/bitops.h>
  12#include <linux/clk.h>
  13#include <linux/err.h>
  14#include <linux/interrupt.h>
  15#include <linux/io.h>
  16#include <linux/irq.h>
  17#include <linux/kernel.h>
  18#include <linux/module.h>
  19#include <linux/platform_device.h>
  20#include <linux/remoteproc.h>
  21
  22#include <mach/clock.h>   /* for davinci_clk_reset_assert/deassert() */
  23
  24#include "remoteproc_internal.h"
  25
  26static char *da8xx_fw_name;
  27module_param(da8xx_fw_name, charp, S_IRUGO);
  28MODULE_PARM_DESC(da8xx_fw_name,
  29                 "Name of DSP firmware file in /lib/firmware (if not specified defaults to 'rproc-dsp-fw')");
  30
  31/*
  32 * OMAP-L138 Technical References:
  33 * http://www.ti.com/product/omap-l138
  34 */
  35#define SYSCFG_CHIPSIG0 BIT(0)
  36#define SYSCFG_CHIPSIG1 BIT(1)
  37#define SYSCFG_CHIPSIG2 BIT(2)
  38#define SYSCFG_CHIPSIG3 BIT(3)
  39#define SYSCFG_CHIPSIG4 BIT(4)
  40
  41/**
  42 * struct da8xx_rproc - da8xx remote processor instance state
  43 * @rproc: rproc handle
  44 * @dsp_clk: placeholder for platform's DSP clk
  45 * @ack_fxn: chip-specific ack function for ack'ing irq
  46 * @irq_data: ack_fxn function parameter
  47 * @chipsig: virt ptr to DSP interrupt registers (CHIPSIG & CHIPSIG_CLR)
  48 * @bootreg: virt ptr to DSP boot address register (HOST1CFG)
  49 * @irq: irq # used by this instance
  50 */
  51struct da8xx_rproc {
  52        struct rproc *rproc;
  53        struct clk *dsp_clk;
  54        void (*ack_fxn)(struct irq_data *data);
  55        struct irq_data *irq_data;
  56        void __iomem *chipsig;
  57        void __iomem *bootreg;
  58        int irq;
  59};
  60
  61/**
  62 * handle_event() - inbound virtqueue message workqueue function
  63 *
  64 * This function is registered as a kernel thread and is scheduled by the
  65 * kernel handler.
  66 */
  67static irqreturn_t handle_event(int irq, void *p)
  68{
  69        struct rproc *rproc = (struct rproc *)p;
  70
  71        /* Process incoming buffers on all our vrings */
  72        rproc_vq_interrupt(rproc, 0);
  73        rproc_vq_interrupt(rproc, 1);
  74
  75        return IRQ_HANDLED;
  76}
  77
  78/**
  79 * da8xx_rproc_callback() - inbound virtqueue message handler
  80 *
  81 * This handler is invoked directly by the kernel whenever the remote
  82 * core (DSP) has modified the state of a virtqueue.  There is no
  83 * "payload" message indicating the virtqueue index as is the case with
  84 * mailbox-based implementations on OMAP4.  As such, this handler "polls"
  85 * each known virtqueue index for every invocation.
  86 */
  87static irqreturn_t da8xx_rproc_callback(int irq, void *p)
  88{
  89        struct rproc *rproc = (struct rproc *)p;
  90        struct da8xx_rproc *drproc = (struct da8xx_rproc *)rproc->priv;
  91        u32 chipsig;
  92
  93        chipsig = readl(drproc->chipsig);
  94        if (chipsig & SYSCFG_CHIPSIG0) {
  95                /* Clear interrupt level source */
  96                writel(SYSCFG_CHIPSIG0, drproc->chipsig + 4);
  97
  98                /*
  99                 * ACK intr to AINTC.
 100                 *
 101                 * It has already been ack'ed by the kernel before calling
 102                 * this function, but since the ARM<->DSP interrupts in the
 103                 * CHIPSIG register are "level" instead of "pulse" variety,
 104                 * we need to ack it after taking down the level else we'll
 105                 * be called again immediately after returning.
 106                 */
 107                drproc->ack_fxn(drproc->irq_data);
 108
 109                return IRQ_WAKE_THREAD;
 110        }
 111
 112        return IRQ_HANDLED;
 113}
 114
 115static int da8xx_rproc_start(struct rproc *rproc)
 116{
 117        struct device *dev = rproc->dev.parent;
 118        struct da8xx_rproc *drproc = (struct da8xx_rproc *)rproc->priv;
 119        struct clk *dsp_clk = drproc->dsp_clk;
 120
 121        /* hw requires the start (boot) address be on 1KB boundary */
 122        if (rproc->bootaddr & 0x3ff) {
 123                dev_err(dev, "invalid boot address: must be aligned to 1KB\n");
 124
 125                return -EINVAL;
 126        }
 127
 128        writel(rproc->bootaddr, drproc->bootreg);
 129
 130        clk_enable(dsp_clk);
 131        davinci_clk_reset_deassert(dsp_clk);
 132
 133        return 0;
 134}
 135
 136static int da8xx_rproc_stop(struct rproc *rproc)
 137{
 138        struct da8xx_rproc *drproc = rproc->priv;
 139
 140        clk_disable(drproc->dsp_clk);
 141
 142        return 0;
 143}
 144
 145/* kick a virtqueue */
 146static void da8xx_rproc_kick(struct rproc *rproc, int vqid)
 147{
 148        struct da8xx_rproc *drproc = (struct da8xx_rproc *)rproc->priv;
 149
 150        /* Interupt remote proc */
 151        writel(SYSCFG_CHIPSIG2, drproc->chipsig);
 152}
 153
 154static struct rproc_ops da8xx_rproc_ops = {
 155        .start = da8xx_rproc_start,
 156        .stop = da8xx_rproc_stop,
 157        .kick = da8xx_rproc_kick,
 158};
 159
 160static int reset_assert(struct device *dev)
 161{
 162        struct clk *dsp_clk;
 163
 164        dsp_clk = clk_get(dev, NULL);
 165        if (IS_ERR(dsp_clk)) {
 166                dev_err(dev, "clk_get error: %ld\n", PTR_ERR(dsp_clk));
 167                return PTR_ERR(dsp_clk);
 168        }
 169
 170        davinci_clk_reset_assert(dsp_clk);
 171        clk_put(dsp_clk);
 172
 173        return 0;
 174}
 175
 176static int da8xx_rproc_probe(struct platform_device *pdev)
 177{
 178        struct device *dev = &pdev->dev;
 179        struct da8xx_rproc *drproc;
 180        struct rproc *rproc;
 181        struct irq_data *irq_data;
 182        struct resource *bootreg_res;
 183        struct resource *chipsig_res;
 184        struct clk *dsp_clk;
 185        void __iomem *chipsig;
 186        void __iomem *bootreg;
 187        int irq;
 188        int ret;
 189
 190        irq = platform_get_irq(pdev, 0);
 191        if (irq < 0) {
 192                dev_err(dev, "platform_get_irq(pdev, 0) error: %d\n", irq);
 193                return irq;
 194        }
 195
 196        irq_data = irq_get_irq_data(irq);
 197        if (!irq_data) {
 198                dev_err(dev, "irq_get_irq_data(%d): NULL\n", irq);
 199                return -EINVAL;
 200        }
 201
 202        bootreg_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 203        bootreg = devm_ioremap_resource(dev, bootreg_res);
 204        if (IS_ERR(bootreg))
 205                return PTR_ERR(bootreg);
 206
 207        chipsig_res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 208        chipsig = devm_ioremap_resource(dev, chipsig_res);
 209        if (IS_ERR(chipsig))
 210                return PTR_ERR(chipsig);
 211
 212        dsp_clk = devm_clk_get(dev, NULL);
 213        if (IS_ERR(dsp_clk)) {
 214                dev_err(dev, "clk_get error: %ld\n", PTR_ERR(dsp_clk));
 215
 216                return PTR_ERR(dsp_clk);
 217        }
 218
 219        rproc = rproc_alloc(dev, "dsp", &da8xx_rproc_ops, da8xx_fw_name,
 220                sizeof(*drproc));
 221        if (!rproc)
 222                return -ENOMEM;
 223
 224        drproc = rproc->priv;
 225        drproc->rproc = rproc;
 226        rproc->has_iommu = false;
 227
 228        platform_set_drvdata(pdev, rproc);
 229
 230        /* everything the ISR needs is now setup, so hook it up */
 231        ret = devm_request_threaded_irq(dev, irq, da8xx_rproc_callback,
 232                                        handle_event, 0, "da8xx-remoteproc",
 233                                        rproc);
 234        if (ret) {
 235                dev_err(dev, "devm_request_threaded_irq error: %d\n", ret);
 236                goto free_rproc;
 237        }
 238
 239        /*
 240         * rproc_add() can end up enabling the DSP's clk with the DSP
 241         * *not* in reset, but da8xx_rproc_start() needs the DSP to be
 242         * held in reset at the time it is called.
 243         */
 244        ret = reset_assert(dev);
 245        if (ret)
 246                goto free_rproc;
 247
 248        drproc->chipsig = chipsig;
 249        drproc->bootreg = bootreg;
 250        drproc->ack_fxn = irq_data->chip->irq_ack;
 251        drproc->irq_data = irq_data;
 252        drproc->irq = irq;
 253        drproc->dsp_clk = dsp_clk;
 254
 255        ret = rproc_add(rproc);
 256        if (ret) {
 257                dev_err(dev, "rproc_add failed: %d\n", ret);
 258                goto free_rproc;
 259        }
 260
 261        return 0;
 262
 263free_rproc:
 264        rproc_put(rproc);
 265
 266        return ret;
 267}
 268
 269static int da8xx_rproc_remove(struct platform_device *pdev)
 270{
 271        struct device *dev = &pdev->dev;
 272        struct rproc *rproc = platform_get_drvdata(pdev);
 273        struct da8xx_rproc *drproc = (struct da8xx_rproc *)rproc->priv;
 274
 275        /*
 276         * It's important to place the DSP in reset before going away,
 277         * since a subsequent insmod of this module may enable the DSP's
 278         * clock before its program/boot-address has been loaded and
 279         * before this module's probe has had a chance to reset the DSP.
 280         * Without the reset, the DSP can lockup permanently when it
 281         * begins executing garbage.
 282         */
 283        reset_assert(dev);
 284
 285        /*
 286         * The devm subsystem might end up releasing things before
 287         * freeing the irq, thus allowing an interrupt to sneak in while
 288         * the device is being removed.  This should prevent that.
 289         */
 290        disable_irq(drproc->irq);
 291
 292        rproc_del(rproc);
 293        rproc_put(rproc);
 294
 295        return 0;
 296}
 297
 298static struct platform_driver da8xx_rproc_driver = {
 299        .probe = da8xx_rproc_probe,
 300        .remove = da8xx_rproc_remove,
 301        .driver = {
 302                .name = "davinci-rproc",
 303        },
 304};
 305
 306module_platform_driver(da8xx_rproc_driver);
 307
 308MODULE_LICENSE("GPL v2");
 309MODULE_DESCRIPTION("DA8XX Remote Processor control driver");
 310