drivers/remoteproc/da8xx_remoteproc.c

   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
  26 static char *da8xx_fw_name;
  27 module_param(da8xx_fw_name, charp, S_IRUGO);
  28 MODULE_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  */
  51 struct 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  */
  67 static 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  */
  87 static 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
 115 static 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
 136 static int da8xx_rproc_stop(struct rproc *rproc)
 137 {
 138         struct da8xx_rproc *drproc = rproc->priv;
 139
 140         davinci_clk_reset_assert(drproc->dsp_clk);
 141         clk_disable(drproc->dsp_clk);
 142
 143         return 0;
 144 }
 145
 146 /* kick a virtqueue */
 147 static void da8xx_rproc_kick(struct rproc *rproc, int vqid)
 148 {
 149         struct da8xx_rproc *drproc = (struct da8xx_rproc *)rproc->priv;
 150
 151         /* Interrupt remote proc */
 152         writel(SYSCFG_CHIPSIG2, drproc->chipsig);
 153 }
 154
 155 static const struct rproc_ops da8xx_rproc_ops = {
 156         .start = da8xx_rproc_start,
 157         .stop = da8xx_rproc_stop,
 158         .kick = da8xx_rproc_kick,
 159 };
 160
 161 static int da8xx_rproc_probe(struct platform_device *pdev)
 162 {
 163         struct device *dev = &pdev->dev;
 164         struct da8xx_rproc *drproc;
 165         struct rproc *rproc;
 166         struct irq_data *irq_data;
 167         struct resource *bootreg_res;
 168         struct resource *chipsig_res;
 169         struct clk *dsp_clk;
 170         void __iomem *chipsig;
 171         void __iomem *bootreg;
 172         int irq;
 173         int ret;
 174
 175         irq = platform_get_irq(pdev, 0);
 176         if (irq < 0) {
 177                 dev_err(dev, "platform_get_irq(pdev, 0) error: %d\n", irq);
 178                 return irq;
 179         }
 180
 181         irq_data = irq_get_irq_data(irq);
 182         if (!irq_data) {
 183                 dev_err(dev, "irq_get_irq_data(%d): NULL\n", irq);
 184                 return -EINVAL;
 185         }
 186
 187         bootreg_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 188         bootreg = devm_ioremap_resource(dev, bootreg_res);
 189         if (IS_ERR(bootreg))
 190                 return PTR_ERR(bootreg);
 191
 192         chipsig_res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 193         chipsig = devm_ioremap_resource(dev, chipsig_res);
 194         if (IS_ERR(chipsig))
 195                 return PTR_ERR(chipsig);
 196
 197         dsp_clk = devm_clk_get(dev, NULL);
 198         if (IS_ERR(dsp_clk)) {
 199                 dev_err(dev, "clk_get error: %ld\n", PTR_ERR(dsp_clk));
 200
 201                 return PTR_ERR(dsp_clk);
 202         }
 203
 204         rproc = rproc_alloc(dev, "dsp", &da8xx_rproc_ops, da8xx_fw_name,
 205                 sizeof(*drproc));
 206         if (!rproc)
 207                 return -ENOMEM;
 208
 209         drproc = rproc->priv;
 210         drproc->rproc = rproc;
 211         drproc->dsp_clk = dsp_clk;
 212         rproc->has_iommu = false;
 213
 214         platform_set_drvdata(pdev, rproc);
 215
 216         /* everything the ISR needs is now setup, so hook it up */
 217         ret = devm_request_threaded_irq(dev, irq, da8xx_rproc_callback,
 218                                         handle_event, 0, "da8xx-remoteproc",
 219                                         rproc);
 220         if (ret) {
 221                 dev_err(dev, "devm_request_threaded_irq error: %d\n", ret);
 222                 goto free_rproc;
 223         }
 224
 225         /*
 226          * rproc_add() can end up enabling the DSP's clk with the DSP
 227          * *not* in reset, but da8xx_rproc_start() needs the DSP to be
 228          * held in reset at the time it is called.
 229          */
 230         ret = davinci_clk_reset_assert(drproc->dsp_clk);
 231         if (ret)
 232                 goto free_rproc;
 233
 234         drproc->chipsig = chipsig;
 235         drproc->bootreg = bootreg;
 236         drproc->ack_fxn = irq_data->chip->irq_ack;
 237         drproc->irq_data = irq_data;
 238         drproc->irq = irq;
 239
 240         ret = rproc_add(rproc);
 241         if (ret) {
 242                 dev_err(dev, "rproc_add failed: %d\n", ret);
 243                 goto free_rproc;
 244         }
 245
 246         return 0;
 247
 248 free_rproc:
 249         rproc_free(rproc);
 250
 251         return ret;
 252 }
 253
 254 static int da8xx_rproc_remove(struct platform_device *pdev)
 255 {
 256         struct rproc *rproc = platform_get_drvdata(pdev);
 257         struct da8xx_rproc *drproc = (struct da8xx_rproc *)rproc->priv;
 258
 259         /*
 260          * The devm subsystem might end up releasing things before
 261          * freeing the irq, thus allowing an interrupt to sneak in while
 262          * the device is being removed.  This should prevent that.
 263          */
 264         disable_irq(drproc->irq);
 265
 266         rproc_del(rproc);
 267         rproc_free(rproc);
 268
 269         return 0;
 270 }
 271
 272 static struct platform_driver da8xx_rproc_driver = {
 273         .probe = da8xx_rproc_probe,
 274         .remove = da8xx_rproc_remove,
 275         .driver = {
 276                 .name = "davinci-rproc",
 277         },
 278 };
 279
 280 module_platform_driver(da8xx_rproc_driver);
 281
 282 MODULE_LICENSE("GPL v2");
 283 MODULE_DESCRIPTION("DA8XX Remote Processor control driver");