--- /dev/null
+/*
+ * 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_RET(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);
+ if (!bootreg_res) {
+ dev_err(dev,
+ "platform_get_resource(IORESOURCE_MEM, 0): NULL\n");
+ return -EADDRNOTAVAIL;
+ }
+
+ chipsig_res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+ if (!chipsig_res) {
+ dev_err(dev,
+ "platform_get_resource(IORESOURCE_MEM, 1): NULL\n");
+ return -EADDRNOTAVAIL;
+ }
+
+ bootreg = devm_ioremap_resource(dev, bootreg_res);
+ if (IS_ERR(bootreg))
+ return PTR_ERR(bootreg);
+
+ 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);
+
+ devm_clk_put(dev, drproc->dsp_clk);
+
+ 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");
projects / deliverable / linux.git / commitdiff
