[PATCH V11 4/7] dma: add Qualcomm Technologies HIDMA channel driver

Andy Shevchenko andy.shevchenko at gmail.com
Mon Jan 4 10:43:13 PST 2016


On Mon, Jan 4, 2016 at 2:06 AM, Sinan Kaya <okaya at codeaurora.org> wrote:
> This patch adds support for hidma engine. The driver consists of two
> logical blocks. The DMA engine interface and the low-level interface.
> The hardware only supports memcpy/memset and this driver only support
> memcpy interface. HW and driver doesn't support slave interface.
>

Looks fine now.

Reviewed-by: Andy Shevchenko <andy.shevchenko at gmail.com>

> Signed-off-by: Sinan Kaya <okaya at codeaurora.org>
> ---
>  drivers/dma/qcom/Kconfig |  10 +
>  drivers/dma/qcom/hidma.c | 744 +++++++++++++++++++++++++++++++++++++++++++++++
>  drivers/dma/qcom/hidma.h | 160 ++++++++++
>  3 files changed, 914 insertions(+)
>  create mode 100644 drivers/dma/qcom/hidma.c
>  create mode 100644 drivers/dma/qcom/hidma.h
>
> diff --git a/drivers/dma/qcom/Kconfig b/drivers/dma/qcom/Kconfig
> index ebe5b8c..5588e1c 100644
> --- a/drivers/dma/qcom/Kconfig
> +++ b/drivers/dma/qcom/Kconfig
> @@ -17,3 +17,13 @@ config QCOM_HIDMA_MGMT
>           start managing the channels. In a virtualized environment,
>           the guest OS would run QCOM_HIDMA channel driver and the
>           hypervisor would run the QCOM_HIDMA_MGMT management driver.
> +
> +config QCOM_HIDMA
> +       tristate "Qualcomm Technologies HIDMA Channel support"
> +       select DMA_ENGINE
> +       help
> +         Enable support for the Qualcomm Technologies HIDMA controller.
> +         The HIDMA controller supports optimized buffer copies
> +         (user to kernel, kernel to kernel, etc.).  It only supports
> +         memcpy interface. The core is not intended for general
> +         purpose slave DMA.
> diff --git a/drivers/dma/qcom/hidma.c b/drivers/dma/qcom/hidma.c
> new file mode 100644
> index 0000000..f8960f1
> --- /dev/null
> +++ b/drivers/dma/qcom/hidma.c
> @@ -0,0 +1,744 @@
> +/*
> + * Qualcomm Technologies HIDMA DMA engine interface
> + *
> + * Copyright (c) 2015, The Linux Foundation. All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 and
> + * only version 2 as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +/*
> + * Copyright (C) Freescale Semicondutor, Inc. 2007, 2008.
> + * Copyright (C) Semihalf 2009
> + * Copyright (C) Ilya Yanok, Emcraft Systems 2010
> + * Copyright (C) Alexander Popov, Promcontroller 2014
> + *
> + * Written by Piotr Ziecik <kosmo at semihalf.com>. Hardware description
> + * (defines, structures and comments) was taken from MPC5121 DMA driver
> + * written by Hongjun Chen <hong-jun.chen at freescale.com>.
> + *
> + * Approved as OSADL project by a majority of OSADL members and funded
> + * by OSADL membership fees in 2009;  for details see www.osadl.org.
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License as published by the Free
> + * Software Foundation; either version 2 of the License, or (at your option)
> + * any later version.
> + *
> + * This program is distributed in the hope that it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> + * more details.
> + *
> + * The full GNU General Public License is included in this distribution in the
> + * file called COPYING.
> + */
> +
> +/* Linux Foundation elects GPLv2 license only. */
> +
> +#include <linux/dmaengine.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/list.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +#include <linux/spinlock.h>
> +#include <linux/of_dma.h>
> +#include <linux/property.h>
> +#include <linux/delay.h>
> +#include <linux/acpi.h>
> +#include <linux/irq.h>
> +#include <linux/atomic.h>
> +#include <linux/pm_runtime.h>
> +
> +#include "../dmaengine.h"
> +#include "hidma.h"
> +
> +/*
> + * Default idle time is 2 seconds. This parameter can
> + * be overridden by changing the following
> + * /sys/bus/platform/devices/QCOM8061:<xy>/power/autosuspend_delay_ms
> + * during kernel boot.
> + */
> +#define HIDMA_AUTOSUSPEND_TIMEOUT              2000
> +#define HIDMA_ERR_INFO_SW                      0xFF
> +#define HIDMA_ERR_CODE_UNEXPECTED_TERMINATE    0x0
> +
> +static inline struct hidma_dev *to_hidma_dev(struct dma_device *dmadev)
> +{
> +       return container_of(dmadev, struct hidma_dev, ddev);
> +}
> +
> +static inline
> +struct hidma_dev *to_hidma_dev_from_lldev(struct hidma_lldev **_lldevp)
> +{
> +       return container_of(_lldevp, struct hidma_dev, lldev);
> +}
> +
> +static inline struct hidma_chan *to_hidma_chan(struct dma_chan *dmach)
> +{
> +       return container_of(dmach, struct hidma_chan, chan);
> +}
> +
> +static inline
> +struct hidma_desc *to_hidma_desc(struct dma_async_tx_descriptor *t)
> +{
> +       return container_of(t, struct hidma_desc, desc);
> +}
> +
> +static void hidma_free(struct hidma_dev *dmadev)
> +{
> +       INIT_LIST_HEAD(&dmadev->ddev.channels);
> +}
> +
> +static unsigned int nr_desc_prm;
> +module_param(nr_desc_prm, uint, 0644);
> +MODULE_PARM_DESC(nr_desc_prm, "number of descriptors (default: 0)");
> +
> +#define HIDMA_MAX_CHANNELS     64
> +static int channel_idx[HIDMA_MAX_CHANNELS] = {
> +       [0 ... (HIDMA_MAX_CHANNELS - 1)] = -1
> +};
> +
> +/*
> + * Each DMA channel is associated with an event channel for interrupt
> + * delivery. The event channel index usually comes from the firmware through
> + * ACPI/DT. When a HIDMA channel is executed in the guest machine context (QEMU)
> + * the device tree gets auto-generated based on the memory and IRQ resources
> + * this driver uses on the host machine. Any device specific paraemeter such as
> + * channel-index gets ignored by the QEMU.
> + * We are using this command line parameter to pass the event channel index to
> + * the guest machine.
> + */
> +static unsigned int num_channel_idx;
> +module_param_array_named(channel_idx, channel_idx, int, &num_channel_idx,
> +                        0644);
> +MODULE_PARM_DESC(channel_idx, "channel index array for the notifications");
> +static atomic_t channel_ref_count;
> +
> +/* process completed descriptors */
> +static void hidma_process_completed(struct hidma_chan *mchan)
> +{
> +       struct dma_device *ddev = mchan->chan.device;
> +       struct hidma_dev *mdma = to_hidma_dev(ddev);
> +       struct dma_async_tx_descriptor *desc;
> +       dma_cookie_t last_cookie;
> +       struct hidma_desc *mdesc;
> +       unsigned long irqflags;
> +       struct list_head list;
> +
> +       INIT_LIST_HEAD(&list);
> +
> +       /* Get all completed descriptors */
> +       spin_lock_irqsave(&mchan->lock, irqflags);
> +       list_splice_tail_init(&mchan->completed, &list);
> +       spin_unlock_irqrestore(&mchan->lock, irqflags);
> +
> +       /* Execute callbacks and run dependencies */
> +       list_for_each_entry(mdesc, &list, node) {
> +               enum dma_status llstat;
> +
> +               desc = &mdesc->desc;
> +
> +               spin_lock_irqsave(&mchan->lock, irqflags);
> +               dma_cookie_complete(desc);
> +               spin_unlock_irqrestore(&mchan->lock, irqflags);
> +
> +               llstat = hidma_ll_status(mdma->lldev, mdesc->tre_ch);
> +               if (desc->callback && (llstat == DMA_COMPLETE))
> +                       desc->callback(desc->callback_param);
> +
> +               last_cookie = desc->cookie;
> +               dma_run_dependencies(desc);
> +       }
> +
> +       /* Free descriptors */
> +       spin_lock_irqsave(&mchan->lock, irqflags);
> +       list_splice_tail_init(&list, &mchan->free);
> +       spin_unlock_irqrestore(&mchan->lock, irqflags);
> +
> +}
> +
> +/*
> + * Called once for each submitted descriptor.
> + * PM is locked once for each descriptor that is currently
> + * in execution.
> + */
> +static void hidma_callback(void *data)
> +{
> +       struct hidma_desc *mdesc = data;
> +       struct hidma_chan *mchan = to_hidma_chan(mdesc->desc.chan);
> +       struct dma_device *ddev = mchan->chan.device;
> +       struct hidma_dev *dmadev = to_hidma_dev(ddev);
> +       unsigned long irqflags;
> +       bool queued = false;
> +
> +       spin_lock_irqsave(&mchan->lock, irqflags);
> +       if (mdesc->node.next) {
> +               /* Delete from the active list, add to completed list */
> +               list_move_tail(&mdesc->node, &mchan->completed);
> +               queued = true;
> +
> +               /* calculate the next running descriptor */
> +               mchan->running = list_first_entry(&mchan->active,
> +                                                 struct hidma_desc, node);
> +       }
> +       spin_unlock_irqrestore(&mchan->lock, irqflags);
> +
> +       hidma_process_completed(mchan);
> +
> +       if (queued) {
> +               pm_runtime_mark_last_busy(dmadev->ddev.dev);
> +               pm_runtime_put_autosuspend(dmadev->ddev.dev);
> +       }
> +}
> +
> +static int hidma_chan_init(struct hidma_dev *dmadev, u32 dma_sig)
> +{
> +       struct hidma_chan *mchan;
> +       struct dma_device *ddev;
> +
> +       mchan = devm_kzalloc(dmadev->ddev.dev, sizeof(*mchan), GFP_KERNEL);
> +       if (!mchan)
> +               return -ENOMEM;
> +
> +       ddev = &dmadev->ddev;
> +       mchan->dma_sig = dma_sig;
> +       mchan->dmadev = dmadev;
> +       mchan->chan.device = ddev;
> +       dma_cookie_init(&mchan->chan);
> +
> +       INIT_LIST_HEAD(&mchan->free);
> +       INIT_LIST_HEAD(&mchan->prepared);
> +       INIT_LIST_HEAD(&mchan->active);
> +       INIT_LIST_HEAD(&mchan->completed);
> +
> +       spin_lock_init(&mchan->lock);
> +       list_add_tail(&mchan->chan.device_node, &ddev->channels);
> +       dmadev->ddev.chancnt++;
> +       return 0;
> +}
> +
> +static void hidma_issue_task(unsigned long arg)
> +{
> +       struct hidma_dev *dmadev = (struct hidma_dev *)arg;
> +
> +       pm_runtime_get_sync(dmadev->ddev.dev);
> +       hidma_ll_start(dmadev->lldev);
> +}
> +
> +static void hidma_issue_pending(struct dma_chan *dmach)
> +{
> +       struct hidma_chan *mchan = to_hidma_chan(dmach);
> +       struct hidma_dev *dmadev = mchan->dmadev;
> +       unsigned long flags;
> +       int status;
> +
> +       spin_lock_irqsave(&mchan->lock, flags);
> +       if (!mchan->running) {
> +               struct hidma_desc *desc = list_first_entry(&mchan->active,
> +                                                          struct hidma_desc,
> +                                                          node);
> +               mchan->running = desc;
> +       }
> +       spin_unlock_irqrestore(&mchan->lock, flags);
> +
> +       /* PM will be released in hidma_callback function. */
> +       status = pm_runtime_get(dmadev->ddev.dev);
> +       if (status < 0)
> +               tasklet_schedule(&dmadev->task);
> +       else
> +               hidma_ll_start(dmadev->lldev);
> +}
> +
> +static enum dma_status hidma_tx_status(struct dma_chan *dmach,
> +                                      dma_cookie_t cookie,
> +                                      struct dma_tx_state *txstate)
> +{
> +       struct hidma_chan *mchan = to_hidma_chan(dmach);
> +       enum dma_status ret;
> +
> +       ret = dma_cookie_status(dmach, cookie, txstate);
> +       if (ret == DMA_COMPLETE)
> +               return ret;
> +
> +       if (mchan->paused && (ret == DMA_IN_PROGRESS)) {
> +               unsigned long flags;
> +               dma_cookie_t runcookie;
> +
> +               spin_lock_irqsave(&mchan->lock, flags);
> +               if (mchan->running)
> +                       runcookie = mchan->running->desc.cookie;
> +               else
> +                       runcookie = -EINVAL;
> +
> +               if (runcookie == cookie)
> +                       ret = DMA_PAUSED;
> +
> +               spin_unlock_irqrestore(&mchan->lock, flags);
> +       }
> +
> +       return ret;
> +}
> +
> +/*
> + * Submit descriptor to hardware.
> + * Lock the PM for each descriptor we are sending.
> + */
> +static dma_cookie_t hidma_tx_submit(struct dma_async_tx_descriptor *txd)
> +{
> +       struct hidma_chan *mchan = to_hidma_chan(txd->chan);
> +       struct hidma_dev *dmadev = mchan->dmadev;
> +       struct hidma_desc *mdesc;
> +       unsigned long irqflags;
> +       dma_cookie_t cookie;
> +
> +       pm_runtime_get_sync(dmadev->ddev.dev);
> +       if (!hidma_ll_isenabled(dmadev->lldev)) {
> +               pm_runtime_mark_last_busy(dmadev->ddev.dev);
> +               pm_runtime_put_autosuspend(dmadev->ddev.dev);
> +               return -ENODEV;
> +       }
> +
> +       mdesc = container_of(txd, struct hidma_desc, desc);
> +       spin_lock_irqsave(&mchan->lock, irqflags);
> +
> +       /* Move descriptor to active */
> +       list_move_tail(&mdesc->node, &mchan->active);
> +
> +       /* Update cookie */
> +       cookie = dma_cookie_assign(txd);
> +
> +       hidma_ll_queue_request(dmadev->lldev, mdesc->tre_ch);
> +       spin_unlock_irqrestore(&mchan->lock, irqflags);
> +
> +       return cookie;
> +}
> +
> +static int hidma_alloc_chan_resources(struct dma_chan *dmach)
> +{
> +       struct hidma_chan *mchan = to_hidma_chan(dmach);
> +       struct hidma_dev *dmadev = mchan->dmadev;
> +       struct hidma_desc *mdesc, *tmp;
> +       unsigned long irqflags;
> +       LIST_HEAD(descs);
> +       unsigned int i;
> +       int rc = 0;
> +
> +       if (mchan->allocated)
> +               return 0;
> +
> +       /* Alloc descriptors for this channel */
> +       for (i = 0; i < dmadev->nr_descriptors; i++) {
> +               mdesc = kzalloc(sizeof(struct hidma_desc), GFP_NOWAIT);
> +               if (!mdesc) {
> +                       rc = -ENOMEM;
> +                       break;
> +               }
> +               dma_async_tx_descriptor_init(&mdesc->desc, dmach);
> +               mdesc->desc.tx_submit = hidma_tx_submit;
> +
> +               rc = hidma_ll_request(dmadev->lldev, mchan->dma_sig,
> +                                     "DMA engine", hidma_callback, mdesc,
> +                                     &mdesc->tre_ch);
> +               if (rc) {
> +                       dev_err(dmach->device->dev,
> +                               "channel alloc failed at %u\n", i);
> +                       kfree(mdesc);
> +                       break;
> +               }
> +               list_add_tail(&mdesc->node, &descs);
> +       }
> +
> +       if (rc) {
> +               /* return the allocated descriptors */
> +               list_for_each_entry_safe(mdesc, tmp, &descs, node) {
> +                       hidma_ll_free(dmadev->lldev, mdesc->tre_ch);
> +                       kfree(mdesc);
> +               }
> +               return rc;
> +       }
> +
> +       spin_lock_irqsave(&mchan->lock, irqflags);
> +       list_splice_tail_init(&descs, &mchan->free);
> +       mchan->allocated = true;
> +       spin_unlock_irqrestore(&mchan->lock, irqflags);
> +       return 1;
> +}
> +
> +static struct dma_async_tx_descriptor *
> +hidma_prep_dma_memcpy(struct dma_chan *dmach, dma_addr_t dest, dma_addr_t src,
> +               size_t len, unsigned long flags)
> +{
> +       struct hidma_chan *mchan = to_hidma_chan(dmach);
> +       struct hidma_desc *mdesc = NULL;
> +       struct hidma_dev *mdma = mchan->dmadev;
> +       unsigned long irqflags;
> +
> +       /* Get free descriptor */
> +       spin_lock_irqsave(&mchan->lock, irqflags);
> +       if (!list_empty(&mchan->free)) {
> +               mdesc = list_first_entry(&mchan->free, struct hidma_desc, node);
> +               list_del(&mdesc->node);
> +       }
> +       spin_unlock_irqrestore(&mchan->lock, irqflags);
> +
> +       if (!mdesc)
> +               return NULL;
> +
> +       hidma_ll_set_transfer_params(mdma->lldev, mdesc->tre_ch,
> +                                    src, dest, len, flags);
> +
> +       /* Place descriptor in prepared list */
> +       spin_lock_irqsave(&mchan->lock, irqflags);
> +       list_add_tail(&mdesc->node, &mchan->prepared);
> +       spin_unlock_irqrestore(&mchan->lock, irqflags);
> +
> +       return &mdesc->desc;
> +}
> +
> +static int hidma_terminate_channel(struct dma_chan *chan)
> +{
> +       struct hidma_chan *mchan = to_hidma_chan(chan);
> +       struct hidma_dev *dmadev = to_hidma_dev(mchan->chan.device);
> +       struct hidma_desc *tmp, *mdesc;
> +       unsigned long irqflags;
> +       LIST_HEAD(list);
> +       int rc;
> +
> +       pm_runtime_get_sync(dmadev->ddev.dev);
> +       /* give completed requests a chance to finish */
> +       hidma_process_completed(mchan);
> +
> +       spin_lock_irqsave(&mchan->lock, irqflags);
> +       list_splice_init(&mchan->active, &list);
> +       list_splice_init(&mchan->prepared, &list);
> +       list_splice_init(&mchan->completed, &list);
> +       spin_unlock_irqrestore(&mchan->lock, irqflags);
> +
> +       /* this suspends the existing transfer */
> +       rc = hidma_ll_pause(dmadev->lldev);
> +       if (rc) {
> +               dev_err(dmadev->ddev.dev, "channel did not pause\n");
> +               goto out;
> +       }
> +
> +       /* return all user requests */
> +       list_for_each_entry_safe(mdesc, tmp, &list, node) {
> +               struct dma_async_tx_descriptor *txd = &mdesc->desc;
> +               dma_async_tx_callback callback = mdesc->desc.callback;
> +               void *param = mdesc->desc.callback_param;
> +
> +               dma_descriptor_unmap(txd);
> +
> +               if (callback)
> +                       callback(param);
> +
> +               dma_run_dependencies(txd);
> +
> +               /* move myself to free_list */
> +               list_move(&mdesc->node, &mchan->free);
> +       }
> +
> +       rc = hidma_ll_resume(dmadev->lldev);
> +out:
> +       pm_runtime_mark_last_busy(dmadev->ddev.dev);
> +       pm_runtime_put_autosuspend(dmadev->ddev.dev);
> +       return rc;
> +}
> +
> +static int hidma_terminate_all(struct dma_chan *chan)
> +{
> +       struct hidma_chan *mchan = to_hidma_chan(chan);
> +       struct hidma_dev *dmadev = to_hidma_dev(mchan->chan.device);
> +       int rc;
> +
> +       rc = hidma_terminate_channel(chan);
> +       if (rc)
> +               return rc;
> +
> +       /* reinitialize the hardware */
> +       pm_runtime_get_sync(dmadev->ddev.dev);
> +       rc = hidma_ll_setup(dmadev->lldev);
> +       pm_runtime_mark_last_busy(dmadev->ddev.dev);
> +       pm_runtime_put_autosuspend(dmadev->ddev.dev);
> +       return rc;
> +}
> +
> +static void hidma_free_chan_resources(struct dma_chan *dmach)
> +{
> +       struct hidma_chan *mchan = to_hidma_chan(dmach);
> +       struct hidma_dev *mdma = mchan->dmadev;
> +       struct hidma_desc *mdesc, *tmp;
> +       unsigned long irqflags;
> +       LIST_HEAD(descs);
> +
> +       /* terminate running transactions and free descriptors */
> +       hidma_terminate_channel(dmach);
> +
> +       spin_lock_irqsave(&mchan->lock, irqflags);
> +
> +       /* Move data */
> +       list_splice_tail_init(&mchan->free, &descs);
> +
> +       /* Free descriptors */
> +       list_for_each_entry_safe(mdesc, tmp, &descs, node) {
> +               hidma_ll_free(mdma->lldev, mdesc->tre_ch);
> +               list_del(&mdesc->node);
> +               kfree(mdesc);
> +       }
> +
> +       mchan->allocated = 0;
> +       spin_unlock_irqrestore(&mchan->lock, irqflags);
> +}
> +
> +static int hidma_pause(struct dma_chan *chan)
> +{
> +       struct hidma_chan *mchan;
> +       struct hidma_dev *dmadev;
> +
> +       mchan = to_hidma_chan(chan);
> +       dmadev = to_hidma_dev(mchan->chan.device);
> +       if (!mchan->paused) {
> +               pm_runtime_get_sync(dmadev->ddev.dev);
> +               if (hidma_ll_pause(dmadev->lldev))
> +                       dev_warn(dmadev->ddev.dev, "channel did not stop\n");
> +               mchan->paused = true;
> +               pm_runtime_mark_last_busy(dmadev->ddev.dev);
> +               pm_runtime_put_autosuspend(dmadev->ddev.dev);
> +       }
> +       return 0;
> +}
> +
> +static int hidma_resume(struct dma_chan *chan)
> +{
> +       struct hidma_chan *mchan;
> +       struct hidma_dev *dmadev;
> +       int rc = 0;
> +
> +       mchan = to_hidma_chan(chan);
> +       dmadev = to_hidma_dev(mchan->chan.device);
> +       if (mchan->paused) {
> +               pm_runtime_get_sync(dmadev->ddev.dev);
> +               rc = hidma_ll_resume(dmadev->lldev);
> +               if (!rc)
> +                       mchan->paused = false;
> +               else
> +                       dev_err(dmadev->ddev.dev,
> +                               "failed to resume the channel");
> +               pm_runtime_mark_last_busy(dmadev->ddev.dev);
> +               pm_runtime_put_autosuspend(dmadev->ddev.dev);
> +       }
> +       return rc;
> +}
> +
> +static irqreturn_t hidma_chirq_handler(int chirq, void *arg)
> +{
> +       struct hidma_lldev *lldev = arg;
> +
> +       /*
> +        * All interrupts are request driven.
> +        * HW doesn't send an interrupt by itself.
> +        */
> +       return hidma_ll_inthandler(chirq, lldev);
> +}
> +
> +static int hidma_probe(struct platform_device *pdev)
> +{
> +       struct hidma_dev *dmadev;
> +       struct resource *trca_resource;
> +       struct resource *evca_resource;
> +       int chirq;
> +       int current_channel_index = atomic_read(&channel_ref_count);
> +       void __iomem *evca;
> +       void __iomem *trca;
> +       int rc;
> +
> +       pm_runtime_set_autosuspend_delay(&pdev->dev, HIDMA_AUTOSUSPEND_TIMEOUT);
> +       pm_runtime_use_autosuspend(&pdev->dev);
> +       pm_runtime_set_active(&pdev->dev);
> +       pm_runtime_enable(&pdev->dev);
> +
> +       trca_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +       trca = devm_ioremap_resource(&pdev->dev, trca_resource);
> +       if (IS_ERR(trca)) {
> +               rc = -ENOMEM;
> +               goto bailout;
> +       }
> +
> +       evca_resource = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> +       evca = devm_ioremap_resource(&pdev->dev, evca_resource);
> +       if (IS_ERR(evca)) {
> +               rc = -ENOMEM;
> +               goto bailout;
> +       }
> +
> +       /*
> +        * This driver only handles the channel IRQs.
> +        * Common IRQ is handled by the management driver.
> +        */
> +       chirq = platform_get_irq(pdev, 0);
> +       if (chirq < 0) {
> +               rc = -ENODEV;
> +               goto bailout;
> +       }
> +
> +       dmadev = devm_kzalloc(&pdev->dev, sizeof(*dmadev), GFP_KERNEL);
> +       if (!dmadev) {
> +               rc = -ENOMEM;
> +               goto bailout;
> +       }
> +
> +       INIT_LIST_HEAD(&dmadev->ddev.channels);
> +       spin_lock_init(&dmadev->lock);
> +       dmadev->ddev.dev = &pdev->dev;
> +       pm_runtime_get_sync(dmadev->ddev.dev);
> +
> +       dma_cap_set(DMA_MEMCPY, dmadev->ddev.cap_mask);
> +       if (WARN_ON(!pdev->dev.dma_mask)) {
> +               rc = -ENXIO;
> +               goto dmafree;
> +       }
> +
> +       dmadev->dev_evca = evca;
> +       dmadev->evca_resource = evca_resource;
> +       dmadev->dev_trca = trca;
> +       dmadev->trca_resource = trca_resource;
> +       dmadev->ddev.device_prep_dma_memcpy = hidma_prep_dma_memcpy;
> +       dmadev->ddev.device_alloc_chan_resources = hidma_alloc_chan_resources;
> +       dmadev->ddev.device_free_chan_resources = hidma_free_chan_resources;
> +       dmadev->ddev.device_tx_status = hidma_tx_status;
> +       dmadev->ddev.device_issue_pending = hidma_issue_pending;
> +       dmadev->ddev.device_pause = hidma_pause;
> +       dmadev->ddev.device_resume = hidma_resume;
> +       dmadev->ddev.device_terminate_all = hidma_terminate_all;
> +       dmadev->ddev.copy_align = 8;
> +
> +       device_property_read_u32(&pdev->dev, "desc-count",
> +                                &dmadev->nr_descriptors);
> +
> +       if (!dmadev->nr_descriptors && nr_desc_prm)
> +               dmadev->nr_descriptors = nr_desc_prm;
> +
> +       if (!dmadev->nr_descriptors) {
> +               rc = -EINVAL;
> +               goto dmafree;
> +       }
> +
> +       if (current_channel_index > HIDMA_MAX_CHANNELS) {
> +               rc = -EINVAL;
> +               goto dmafree;
> +       }
> +
> +       dmadev->chidx = -1;
> +       device_property_read_u32(&pdev->dev, "channel-index", &dmadev->chidx);
> +
> +       /* kernel command line override for the guest machine */
> +       if (channel_idx[current_channel_index] != -1)
> +               dmadev->chidx = channel_idx[current_channel_index];
> +
> +       if (dmadev->chidx == -1) {
> +               rc = -EINVAL;
> +               goto dmafree;
> +       }
> +
> +       /* Set DMA mask to 64 bits. */
> +       rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
> +       if (rc) {
> +               dev_warn(&pdev->dev, "unable to set coherent mask to 64");
> +               rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
> +               if (rc)
> +                       goto dmafree;
> +       }
> +
> +       dmadev->lldev = hidma_ll_init(dmadev->ddev.dev,
> +                                     dmadev->nr_descriptors, dmadev->dev_trca,
> +                                     dmadev->dev_evca, dmadev->chidx);
> +       if (!dmadev->lldev) {
> +               rc = -EPROBE_DEFER;
> +               goto dmafree;
> +       }
> +
> +       rc = devm_request_irq(&pdev->dev, chirq, hidma_chirq_handler, 0,
> +                             "qcom-hidma", dmadev->lldev);
> +       if (rc)
> +               goto uninit;
> +
> +       INIT_LIST_HEAD(&dmadev->ddev.channels);
> +       rc = hidma_chan_init(dmadev, 0);
> +       if (rc)
> +               goto uninit;
> +
> +       rc = dma_async_device_register(&dmadev->ddev);
> +       if (rc)
> +               goto uninit;
> +
> +       dmadev->irq = chirq;
> +       tasklet_init(&dmadev->task, hidma_issue_task, (unsigned long)dmadev);
> +       dev_info(&pdev->dev, "HI-DMA engine driver registration complete\n");
> +       platform_set_drvdata(pdev, dmadev);
> +       pm_runtime_mark_last_busy(dmadev->ddev.dev);
> +       pm_runtime_put_autosuspend(dmadev->ddev.dev);
> +       atomic_inc(&channel_ref_count);
> +       return 0;
> +
> +uninit:
> +       hidma_ll_uninit(dmadev->lldev);
> +dmafree:
> +       if (dmadev)
> +               hidma_free(dmadev);
> +bailout:
> +       pm_runtime_put_sync(&pdev->dev);
> +       pm_runtime_disable(&pdev->dev);
> +       return rc;
> +}
> +
> +static int hidma_remove(struct platform_device *pdev)
> +{
> +       struct hidma_dev *dmadev = platform_get_drvdata(pdev);
> +
> +       pm_runtime_get_sync(dmadev->ddev.dev);
> +       dma_async_device_unregister(&dmadev->ddev);
> +       devm_free_irq(dmadev->ddev.dev, dmadev->irq, dmadev->lldev);
> +       hidma_ll_uninit(dmadev->lldev);
> +       hidma_free(dmadev);
> +
> +       dev_info(&pdev->dev, "HI-DMA engine removed\n");
> +       pm_runtime_put_sync_suspend(&pdev->dev);
> +       pm_runtime_disable(&pdev->dev);
> +
> +       return 0;
> +}
> +
> +#if IS_ENABLED(CONFIG_ACPI)
> +static const struct acpi_device_id hidma_acpi_ids[] = {
> +       {"QCOM8061"},
> +       {},
> +};
> +#endif
> +
> +static const struct of_device_id hidma_match[] = {
> +       {.compatible = "qcom,hidma-1.0",},
> +       {},
> +};
> +
> +MODULE_DEVICE_TABLE(of, hidma_match);
> +
> +static struct platform_driver hidma_driver = {
> +       .probe = hidma_probe,
> +       .remove = hidma_remove,
> +       .driver = {
> +                  .name = "hidma",
> +                  .of_match_table = hidma_match,
> +                  .acpi_match_table = ACPI_PTR(hidma_acpi_ids),
> +       },
> +};
> +
> +module_platform_driver(hidma_driver);
> +MODULE_LICENSE("GPL v2");
> diff --git a/drivers/dma/qcom/hidma.h b/drivers/dma/qcom/hidma.h
> new file mode 100644
> index 0000000..231e306
> --- /dev/null
> +++ b/drivers/dma/qcom/hidma.h
> @@ -0,0 +1,160 @@
> +/*
> + * Qualcomm Technologies HIDMA data structures
> + *
> + * Copyright (c) 2014, The Linux Foundation. All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 and
> + * only version 2 as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#ifndef QCOM_HIDMA_H
> +#define QCOM_HIDMA_H
> +
> +#include <linux/kfifo.h>
> +#include <linux/interrupt.h>
> +#include <linux/dmaengine.h>
> +
> +#define TRE_SIZE                       32 /* each TRE is 32 bytes  */
> +#define TRE_CFG_IDX                    0
> +#define TRE_LEN_IDX                    1
> +#define TRE_SRC_LOW_IDX                2
> +#define TRE_SRC_HI_IDX                 3
> +#define TRE_DEST_LOW_IDX               4
> +#define TRE_DEST_HI_IDX                5
> +
> +struct hidma_tx_status {
> +       u8 err_info;                    /* error record in this transfer    */
> +       u8 err_code;                    /* completion code                  */
> +};
> +
> +struct hidma_tre {
> +       atomic_t allocated;             /* if this channel is allocated     */
> +       bool queued;                    /* flag whether this is pending     */
> +       u16 status;                     /* status                           */
> +       u32 chidx;                      /* index of the tre                 */
> +       u32 dma_sig;                    /* signature of the tre             */
> +       const char *dev_name;           /* name of the device               */
> +       void (*callback)(void *data);   /* requester callback               */
> +       void *data;                     /* Data associated with this channel*/
> +       struct hidma_lldev *lldev;      /* lldma device pointer             */
> +       u32 tre_local[TRE_SIZE / sizeof(u32) + 1]; /* TRE local copy        */
> +       u32 tre_index;                  /* the offset where this was written*/
> +       u32 int_flags;                  /* interrupt flags                  */
> +};
> +
> +struct hidma_lldev {
> +       bool initialized;               /* initialized flag               */
> +       u8 trch_state;                  /* trch_state of the device       */
> +       u8 evch_state;                  /* evch_state of the device       */
> +       u8 chidx;                       /* channel index in the core      */
> +       u32 nr_tres;                    /* max number of configs          */
> +       spinlock_t lock;                /* reentrancy                     */
> +       struct hidma_tre *trepool;      /* trepool of user configs */
> +       struct device *dev;             /* device                         */
> +       void __iomem *trca;             /* Transfer Channel address       */
> +       void __iomem *evca;             /* Event Channel address          */
> +       struct hidma_tre
> +               **pending_tre_list;     /* Pointers to pending TREs       */
> +       struct hidma_tx_status
> +               *tx_status_list;        /* Pointers to pending TREs status*/
> +       s32 pending_tre_count;          /* Number of TREs pending         */
> +
> +       void *tre_ring;                 /* TRE ring                       */
> +       dma_addr_t tre_ring_handle;     /* TRE ring to be shared with HW  */
> +       u32 tre_ring_size;              /* Byte size of the ring          */
> +       u32 tre_processed_off;          /* last processed TRE             */
> +
> +       void *evre_ring;                /* EVRE ring                       */
> +       dma_addr_t evre_ring_handle;    /* EVRE ring to be shared with HW  */
> +       u32 evre_ring_size;             /* Byte size of the ring           */
> +       u32 evre_processed_off;         /* last processed EVRE             */
> +
> +       u32 tre_write_offset;           /* TRE write location              */
> +       struct tasklet_struct task;     /* task delivering notifications   */
> +       DECLARE_KFIFO_PTR(handoff_fifo,
> +               struct hidma_tre *);    /* pending TREs FIFO               */
> +};
> +
> +struct hidma_desc {
> +       struct dma_async_tx_descriptor  desc;
> +       /* link list node for this channel*/
> +       struct list_head                node;
> +       u32                             tre_ch;
> +};
> +
> +struct hidma_chan {
> +       bool                            paused;
> +       bool                            allocated;
> +       char                            dbg_name[16];
> +       u32                             dma_sig;
> +
> +       /*
> +        * active descriptor on this channel
> +        * It is used by the DMA complete notification to
> +        * locate the descriptor that initiated the transfer.
> +        */
> +       struct dentry                   *debugfs;
> +       struct dentry                   *stats;
> +       struct hidma_dev                *dmadev;
> +       struct hidma_desc               *running;
> +
> +       struct dma_chan                 chan;
> +       struct list_head                free;
> +       struct list_head                prepared;
> +       struct list_head                active;
> +       struct list_head                completed;
> +
> +       /* Lock for this structure */
> +       spinlock_t                      lock;
> +};
> +
> +struct hidma_dev {
> +       int                             irq;
> +       int                             chidx;
> +       u32                             nr_descriptors;
> +
> +       struct hidma_lldev              *lldev;
> +       void                            __iomem *dev_trca;
> +       struct resource                 *trca_resource;
> +       void                            __iomem *dev_evca;
> +       struct resource                 *evca_resource;
> +
> +       /* used to protect the pending channel list*/
> +       spinlock_t                      lock;
> +       struct dma_device               ddev;
> +
> +       struct dentry                   *debugfs;
> +       struct dentry                   *stats;
> +
> +       /* Task delivering issue_pending */
> +       struct tasklet_struct           task;
> +};
> +
> +int hidma_ll_request(struct hidma_lldev *llhndl, u32 dev_id,
> +                       const char *dev_name,
> +                       void (*callback)(void *data), void *data, u32 *tre_ch);
> +
> +void hidma_ll_free(struct hidma_lldev *llhndl, u32 tre_ch);
> +enum dma_status hidma_ll_status(struct hidma_lldev *llhndl, u32 tre_ch);
> +bool hidma_ll_isenabled(struct hidma_lldev *llhndl);
> +void hidma_ll_queue_request(struct hidma_lldev *llhndl, u32 tre_ch);
> +void hidma_ll_start(struct hidma_lldev *llhndl);
> +int hidma_ll_pause(struct hidma_lldev *llhndl);
> +int hidma_ll_resume(struct hidma_lldev *llhndl);
> +void hidma_ll_set_transfer_params(struct hidma_lldev *llhndl, u32 tre_ch,
> +       dma_addr_t src, dma_addr_t dest, u32 len, u32 flags);
> +int hidma_ll_setup(struct hidma_lldev *lldev);
> +struct hidma_lldev *hidma_ll_init(struct device *dev, u32 max_channels,
> +                       void __iomem *trca, void __iomem *evca,
> +                       u8 chidx);
> +int hidma_ll_uninit(struct hidma_lldev *llhndl);
> +irqreturn_t hidma_ll_inthandler(int irq, void *arg);
> +void hidma_cleanup_pending_tre(struct hidma_lldev *llhndl, u8 err_info,
> +                               u8 err_code);
> +#endif
> --
> Qualcomm Technologies, Inc. on behalf of Qualcomm Innovation Center, Inc.
> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project
>
> --
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-- 
With Best Regards,
Andy Shevchenko



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