/*
* Remote processor machine-specific module for DA8XX
*
* Copyright (C) 2013 Texas Instruments, Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*/
#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/remoteproc.h>
#include <mach/clock.h> /* for davinci_clk_reset_assert/deassert() */
#include "remoteproc_internal.h"
static char *da8xx_fw_name;
module_param(da8xx_fw_name, charp, S_IRUGO);
MODULE_PARM_DESC(da8xx_fw_name,
"\n\t\tName of DSP firmware file in /lib/firmware"
" (if not specified defaults to 'rproc-dsp-fw')");
/*
* OMAP-L138 Technical References:
* http://www.ti.com/product/omap-l138
*/
#define SYSCFG_CHIPSIG0 BIT(0)
#define SYSCFG_CHIPSIG1 BIT(1)
#define SYSCFG_CHIPSIG2 BIT(2)
#define SYSCFG_CHIPSIG3 BIT(3)
#define SYSCFG_CHIPSIG4 BIT(4)
/**
* struct da8xx_rproc - da8xx remote processor instance state
* @rproc: rproc handle
* @dsp_clk: placeholder for platform's DSP clk
* @ack_fxn: chip-specific ack function for ack'ing irq
* @irq_data: ack_fxn function parameter
* @chipsig: virt ptr to DSP interrupt registers (CHIPSIG & CHIPSIG_CLR)
* @bootreg: virt ptr to DSP boot address register (HOST1CFG)
* @irq: irq # used by this instance
*/
struct da8xx_rproc {
struct rproc *rproc;
struct clk *dsp_clk;
void (*ack_fxn)(struct irq_data *data);
struct irq_data *irq_data;
void __iomem *chipsig;
void __iomem *bootreg;
int irq;
};
/**
* handle_event() - inbound virtqueue message workqueue function
*
* This function is registered as a kernel thread and is scheduled by the
* kernel handler.
*/
static irqreturn_t handle_event(int irq, void *p)
{
struct rproc *rproc = (struct rproc *)p;
/* Process incoming buffers on all our vrings */
rproc_vq_interrupt(rproc, 0);
rproc_vq_interrupt(rproc, 1);
return IRQ_HANDLED;
}
/**
* da8xx_rproc_callback() - inbound virtqueue message handler
*
* This handler is invoked directly by the kernel whenever the remote
* core (DSP) has modified the state of a virtqueue. There is no
* "payload" message indicating the virtqueue index as is the case with
* mailbox-based implementations on OMAP4. As such, this handler "polls"
* each known virtqueue index for every invocation.
*/
static irqreturn_t da8xx_rproc_callback(int irq, void *p)
{
struct rproc *rproc = (struct rproc *)p;
struct da8xx_rproc *drproc = (struct da8xx_rproc *)rproc->priv;
u32 chipsig;
chipsig = readl(drproc->chipsig);
if (chipsig & SYSCFG_CHIPSIG0) {
/* Clear interrupt level source */
writel(SYSCFG_CHIPSIG0, drproc->chipsig + 4);
/*
* ACK intr to AINTC.
*
* It has already been ack'ed by the kernel before calling
* this function, but since the ARM<->DSP interrupts in the
* CHIPSIG register are "level" instead of "pulse" variety,
* we need to ack it after taking down the level else we'll
* be called again immediately after returning.
*/
drproc->ack_fxn(drproc->irq_data);
return IRQ_WAKE_THREAD;
}
return IRQ_HANDLED;
}
static int da8xx_rproc_start(struct rproc *rproc)
{
struct device *dev = rproc->dev.parent;
struct da8xx_rproc *drproc = (struct da8xx_rproc *)rproc->priv;
struct clk *dsp_clk = drproc->dsp_clk;
/* hw requires the start (boot) address be on 1KB boundary */
if (rproc->bootaddr & 0x3ff) {
dev_err(dev, "invalid boot address: must be aligned to 1KB\n");
return -EINVAL;
}
writel(rproc->bootaddr, drproc->bootreg);
clk_enable(dsp_clk);
davinci_clk_reset_deassert(dsp_clk);
return 0;
}
static int da8xx_rproc_stop(struct rproc *rproc)
{
struct da8xx_rproc *drproc = rproc->priv;
clk_disable(drproc->dsp_clk);
return 0;
}
/* kick a virtqueue */
static void da8xx_rproc_kick(struct rproc *rproc, int vqid)
{
struct da8xx_rproc *drproc = (struct da8xx_rproc *)rproc->priv;
/* Interupt remote proc */
writel(SYSCFG_CHIPSIG2, drproc->chipsig);
}
static struct rproc_ops da8xx_rproc_ops = {
.start = da8xx_rproc_start,
.stop = da8xx_rproc_stop,
.kick = da8xx_rproc_kick,
};
static int reset_assert(struct device *dev)
{
struct clk *dsp_clk;
dsp_clk = clk_get(dev, NULL);
if (IS_ERR(dsp_clk)) {
dev_err(dev, "clk_get error: %ld\n", PTR_ERR(dsp_clk));
return PTR_ERR(dsp_clk);
}
davinci_clk_reset_assert(dsp_clk);
clk_put(dsp_clk);
return 0;
}
static int da8xx_rproc_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct da8xx_rproc *drproc;
struct rproc *rproc;
struct irq_data *irq_data;
struct resource *bootreg_res;
struct resource *chipsig_res;
struct clk *dsp_clk;
void __iomem *chipsig;
void __iomem *bootreg;
int irq;
int ret;
irq = platform_get_irq(pdev, 0);
if (irq < 0) {
dev_err(dev, "platform_get_irq(pdev, 0) error: %d\n", irq);
return irq;
}
irq_data = irq_get_irq_data(irq);
if (!irq_data) {
dev_err(dev, "irq_get_irq_data(%d): NULL\n", irq);
return -EINVAL;
}
bootreg_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
bootreg = devm_ioremap_resource(dev, bootreg_res);
if (IS_ERR(bootreg))
return PTR_ERR(bootreg);
chipsig_res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
chipsig = devm_ioremap_resource(dev, chipsig_res);
if (IS_ERR(chipsig))
return PTR_ERR(chipsig);
dsp_clk = devm_clk_get(dev, NULL);
if (IS_ERR(dsp_clk)) {
dev_err(dev, "clk_get error: %ld\n", PTR_ERR(dsp_clk));
return PTR_ERR(dsp_clk);
}
rproc = rproc_alloc(dev, "dsp", &da8xx_rproc_ops, da8xx_fw_name,
sizeof(*drproc));
if (!rproc)
return -ENOMEM;
drproc = rproc->priv;
drproc->rproc = rproc;
platform_set_drvdata(pdev, rproc);
/* everything the ISR needs is now setup, so hook it up */
ret = devm_request_threaded_irq(dev, irq, da8xx_rproc_callback,
handle_event, 0, "da8xx-remoteproc",
rproc);
if (ret) {
dev_err(dev, "devm_request_threaded_irq error: %d\n", ret);
goto free_rproc;
}
/*
* rproc_add() can end up enabling the DSP's clk with the DSP
* *not* in reset, but da8xx_rproc_start() needs the DSP to be
* held in reset at the time it is called.
*/
ret = reset_assert(dev);
if (ret)
goto free_rproc;
drproc->chipsig = chipsig;
drproc->bootreg = bootreg;
drproc->ack_fxn = irq_data->chip->irq_ack;
drproc->irq_data = irq_data;
drproc->irq = irq;
drproc->dsp_clk = dsp_clk;
ret = rproc_add(rproc);
if (ret) {
dev_err(dev, "rproc_add failed: %d\n", ret);
goto free_rproc;
}
return 0;
free_rproc:
rproc_put(rproc);
return ret;
}
static int da8xx_rproc_remove(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct rproc *rproc = platform_get_drvdata(pdev);
struct da8xx_rproc *drproc = (struct da8xx_rproc *)rproc->priv;
/*
* It's important to place the DSP in reset before going away,
* since a subsequent insmod of this module may enable the DSP's
* clock before its program/boot-address has been loaded and
* before this module's probe has had a chance to reset the DSP.
* Without the reset, the DSP can lockup permanently when it
* begins executing garbage.
*/
reset_assert(dev);
/*
* The devm subsystem might end up releasing things before
* freeing the irq, thus allowing an interrupt to sneak in while
* the device is being removed. This should prevent that.
*/
disable_irq(drproc->irq);
rproc_del(rproc);
rproc_put(rproc);
return 0;
}
static struct platform_driver da8xx_rproc_driver = {
.probe = da8xx_rproc_probe,
.remove = da8xx_rproc_remove,
.driver = {
.name = "davinci-rproc",
.owner = THIS_MODULE,
},
};
module_platform_driver(da8xx_rproc_driver);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("DA8XX Remote Processor control driver");
