drivers/remoteproc/da8xx_remoteproc.c - linux - Git at Google

 /*
  * 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",
 	},
 };

 module_platform_driver(da8xx_rproc_driver);

 MODULE_LICENSE("GPL v2");
 MODULE_DESCRIPTION("DA8XX Remote Processor control driver");
	/*
	* 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",
	},
	};

	module_platform_driver(da8xx_rproc_driver);

	MODULE_LICENSE("GPL v2");
	MODULE_DESCRIPTION("DA8XX Remote Processor control driver");