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linux-next/drivers/remoteproc/da8xx_remoteproc.c
Suman Anna a63c70d4dc remoteproc/davinci: fix unbalanced reset between start and stop ops
The davinci remoteproc driver is currently de-asserting the reset in
its rproc .start() ops, but is not asserting the reset in its .stop()
ops. This leaves the remote processor to not boot properly when using
the sysfs 'state' variable between multiple start and stop operations.
On the other hand, a reset is being asserted unconditionally in the
driver remove function to alleviate some of these issues.

Move this reset assertion logic into the .stop() ops implementation
to fix the sysfs state-machine and the unbalanced reset. The logic
from remove is still effective since .stop() ops will be invoked
during the remove due to the enabled 'auto-boot' support. The probe
already has support for asserting the reset in case the DSP is not
in reset for some reason.

Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
2017-06-25 14:00:54 -07:00

284 lines
7.1 KiB
C

/*
* 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,
"Name 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;
davinci_clk_reset_assert(drproc->dsp_clk);
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;
/* Interrupt remote proc */
writel(SYSCFG_CHIPSIG2, drproc->chipsig);
}
static const struct rproc_ops da8xx_rproc_ops = {
.start = da8xx_rproc_start,
.stop = da8xx_rproc_stop,
.kick = da8xx_rproc_kick,
};
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;
drproc->dsp_clk = dsp_clk;
rproc->has_iommu = false;
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 = davinci_clk_reset_assert(drproc->dsp_clk);
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;
ret = rproc_add(rproc);
if (ret) {
dev_err(dev, "rproc_add failed: %d\n", ret);
goto free_rproc;
}
return 0;
free_rproc:
rproc_free(rproc);
return ret;
}
static int da8xx_rproc_remove(struct platform_device *pdev)
{
struct rproc *rproc = platform_get_drvdata(pdev);
struct da8xx_rproc *drproc = (struct da8xx_rproc *)rproc->priv;
/*
* 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_free(rproc);
return 0;
}
static struct platform_driver da8xx_rproc_driver = {
.probe = da8xx_rproc_probe,
.remove = da8xx_rproc_remove,
.driver = {
.name = "davinci-rproc",
},
};
module_platform_driver(da8xx_rproc_driver);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("DA8XX Remote Processor control driver");