[PATCH v5 6/9] ARM: davinci: Remoteproc driver support for OMAP-L138 DSP
Sekhar Nori
nsekhar at ti.com
Mon Jan 21 00:38:43 EST 2013
On 1/11/2013 5:53 AM, Robert Tivy wrote:
> Adding a remoteproc driver implementation for OMAP-L138 DSP
>
> Signed-off-by: Robert Tivy <rtivy at ti.com>
> ---
> drivers/remoteproc/Kconfig | 23 ++
> drivers/remoteproc/Makefile | 1 +
> drivers/remoteproc/davinci_remoteproc.c | 307 ++++++++++++++++++++++++
> include/linux/platform_data/da8xx-remoteproc.h | 33 +++
naming the driver davinci_remoteproc.c and platform data as
da8xx-remoteproc.h is odd. The driver looks really specific to omap-l138
so may be call the driver da8xx-remoteproc.c?
> diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig
> index 96ce101..7d3a5e0 100644
> --- a/drivers/remoteproc/Kconfig
> +++ b/drivers/remoteproc/Kconfig
> @@ -41,4 +41,27 @@ config STE_MODEM_RPROC
> This can be either built-in or a loadable module.
> If unsure say N.
>
> +config DAVINCI_REMOTEPROC
> + tristate "DaVinci DA850/OMAPL138 remoteproc support (EXPERIMENTAL)"
> + depends on ARCH_DAVINCI_DA850
> + select REMOTEPROC
> + select RPMSG
> + select FW_LOADER
> + select CMA
> + default n
> + help
> + Say y here to support DaVinci DA850/OMAPL138 remote processors
> + via the remote processor framework.
> +
> + You want to say y here in order to enable AMP
> + use-cases to run on your platform (multimedia codecs are
> + offloaded to remote DSP processors using this framework).
> +
> + It's safe to say n here if you're not interested in multimedia
> + offloading or just want a bare minimum kernel.
> + This feature is considered EXPERIMENTAL, due to it not having
> + any previous exposure to the general public and therefore
> + limited developer-based testing.
This is probably true in general for remoteproc (I am being warned a lot
by the framework when using it) so may be you can drop this specific
reference.
> diff --git a/drivers/remoteproc/davinci_remoteproc.c b/drivers/remoteproc/davinci_remoteproc.c
> new file mode 100644
> index 0000000..fc6fd72
> --- /dev/null
> +++ b/drivers/remoteproc/davinci_remoteproc.c
> @@ -0,0 +1,307 @@
> +/*
> + * Remote processor machine-specific module for Davinci
> + *
> + * Copyright (C) 2011-2012 Texas Instruments, Inc.
2013?
> + *
> + * 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.
> + */
> +
> +#define pr_fmt(fmt) "%s: " fmt, __func__
You dont seem to be using this anywhere.
> +
> +#include <linux/kernel.h>
> +#include <linux/err.h>
> +#include <linux/printk.h>
> +#include <linux/bitops.h>
> +#include <linux/platform_device.h>
> +#include <linux/remoteproc.h>
> +#include <linux/platform_data/da8xx-remoteproc.h>
> +#include <linux/clk.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/interrupt.h>
> +#include <linux/irq.h>
It will be nice to keep this sorted. It avoids duplicate includes later.
> +static char *fw_name;
> +module_param(fw_name, charp, S_IRUGO);
> +MODULE_PARM_DESC(fw_name, "\n\t\tName of DSP firmware file in /lib/firmware");
> +
> +/*
> + * OMAP-L138 Technical References:
> + * http://www.ti.com/product/omap-l138
> + */
> +#define SYSCFG_CHIPSIG_OFFSET 0x174
> +#define SYSCFG_CHIPSIG_CLR_OFFSET 0x178
> +#define SYSCFG_CHIPINT0 (1 << 0)
> +#define SYSCFG_CHIPINT1 (1 << 1)
> +#define SYSCFG_CHIPINT2 (1 << 2)
> +#define SYSCFG_CHIPINT3 (1 << 3)
You can use BIT(x) here.
> +
> +/**
> + * struct davinci_rproc - davinci remote processor state
> + * @rproc: rproc handle
> + */
> +struct davinci_rproc {
> + struct rproc *rproc;
> + struct clk *dsp_clk;
> +};
> +
> +static void __iomem *syscfg0_base;
> +static struct platform_device *remoteprocdev;
> +static struct irq_data *irq_data;
> +static void (*ack_fxn)(struct irq_data *data);
> +static int irq;
> +
> +/**
> + * handle_event() - inbound virtqueue message workqueue function
> + *
> + * This funciton 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 = platform_get_drvdata(remoteprocdev);
> +
> + /* Process incoming buffers on our vring */
> + while (IRQ_HANDLED == rproc_vq_interrupt(rproc, 0))
> + ;
> +
> + /* Must allow wakeup of potenitally blocking senders: */
> + rproc_vq_interrupt(rproc, 1);
> +
> + return IRQ_HANDLED;
> +}
> +
> +/**
> + * davinci_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 davinci_rproc_callback(int irq, void *p)
> +{
> + if (readl(syscfg0_base + SYSCFG_CHIPSIG_OFFSET) & SYSCFG_CHIPINT0) {
personally I think using a variable to read the register and then
testing its value inside if() is more readable.
> + /* Clear interrupt level source */
> + writel(SYSCFG_CHIPINT0,
> + syscfg0_base + SYSCFG_CHIPSIG_CLR_OFFSET);
> +
> + /*
> + * 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.
> + */
> + ack_fxn(irq_data);
Don't really like interrupt controller functions being invoked like this
but I don't understand the underlying issue well enough to suggest an
alternate.
> +
> + return IRQ_WAKE_THREAD;
> + }
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int davinci_rproc_start(struct rproc *rproc)
> +{
> + struct platform_device *pdev = to_platform_device(rproc->dev.parent);
> + struct device *dev = rproc->dev.parent;
> + struct davinci_rproc *drproc = rproc->priv;
> + struct clk *dsp_clk;
> + struct resource *r;
> + unsigned long host1cfg_physaddr;
> + unsigned int host1cfg_offset;
> + int ret;
> +
> + remoteprocdev = pdev;
> +
> + /* 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;
> + }
> +
> + r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
Along with moving this to probe as Ohad requested, you can use
devm_request_and_ioremap() to simplify the error paths here. Have a look
at: Documentation/driver-model/devres.txt
> + if (IS_ERR_OR_NULL(r)) {
> + dev_err(dev, "platform_get_resource() error: %ld\n",
> + PTR_ERR(r));
> +
> + return PTR_ERR(r);
> + }
> + host1cfg_physaddr = (unsigned long)r->start;
> +
> + 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 (IS_ERR_OR_NULL(irq_data)) {
> + dev_err(dev, "irq_get_irq_data(%d) error: %ld\n",
> + irq, PTR_ERR(irq_data));
> +
> + return PTR_ERR(irq_data);
> + }
> + ack_fxn = irq_data->chip->irq_ack;
> +
> + ret = request_threaded_irq(irq, davinci_rproc_callback, handle_event,
> + 0, "davinci-remoteproc", drproc);
> + if (ret) {
> + dev_err(dev, "request_threaded_irq error: %d\n", ret);
> +
> + return ret;
> + }
> +
> + syscfg0_base = ioremap(host1cfg_physaddr & PAGE_MASK, SZ_4K);
> + host1cfg_offset = offset_in_page(host1cfg_physaddr);
> + writel(rproc->bootaddr, syscfg0_base + host1cfg_offset);
> +
> + dsp_clk = clk_get(dev, NULL);
devm_clk_get() here.
> + if (IS_ERR_OR_NULL(dsp_clk)) {
> + dev_err(dev, "clk_get error: %ld\n", PTR_ERR(dsp_clk));
> + ret = PTR_ERR(dsp_clk);
> + goto fail;
> + }
> + clk_enable(dsp_clk);
> + davinci_clk_reset_deassert(dsp_clk);
> +
> + drproc->dsp_clk = dsp_clk;
> +
> + return 0;
> +fail:
> + free_irq(irq, drproc);
> + iounmap(syscfg0_base);
> +
> + return ret;
> +}
> +
> +static int davinci_rproc_stop(struct rproc *rproc)
> +{
> + struct davinci_rproc *drproc = rproc->priv;
> + struct clk *dsp_clk = drproc->dsp_clk;
> +
> + clk_disable(dsp_clk);
> + clk_put(dsp_clk);
> + iounmap(syscfg0_base);
> + free_irq(irq, drproc);
> +
> + return 0;
> +}
> +
> +/* kick a virtqueue */
> +static void davinci_rproc_kick(struct rproc *rproc, int vqid)
> +{
> + int timed_out;
> + unsigned long timeout;
> +
> + timed_out = 0;
> + timeout = jiffies + HZ/100;
> +
> + /* Poll for ack from other side first */
> + while (readl(syscfg0_base + SYSCFG_CHIPSIG_OFFSET) &
> + SYSCFG_CHIPINT2)
If there is a context switch here long enough ..
> + if (time_after(jiffies, timeout)) {
.. then time_after() might return true and you will erroneously report a
timeout even though hardware is working perfectly fine.
Thanks,
Sekhar
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