Re: [alsa-devel] [PATCH v1 1/5] dmaengine: mmp_tdma: add mmp tdma support

On Mon, 2012-06-04 at 14:37 +0800, Zhangfei Gao wrote:

Add support for two-channel dma under dmaengine support: mmp-adma and pxa910-squ

Signed-off-by: Zhangfei Gao zhangfei.gao@marvell.com Signed-off-by: Leo Yan leoy@marvell.com Signed-off-by: Qiao Zhou zhouqiao@marvell.com

+static int mmp_tdma_clear_chan_irq(struct mmp_tdma_chan *tdmac) +{

• u32 reg = readl(tdmac->reg_base + TDISR);
• if (reg & TDISR_COMP) {

• /* clear irq */
  

• reg &= ~TDISR_COMP;
  

• writel(reg, tdmac->reg_base + TDISR);
  

• return 1;
  

hrmm.?

• }
• return 0;

+}

+static irqreturn_t mmp_tdma_chan_handler(int irq, void *dev_id) +{

• struct mmp_tdma_chan *tdmac = dev_id;
• if (mmp_tdma_clear_chan_irq(tdmac)) {

• tdmac->pos = (tdmac->pos + tdmac->period_len) % tdmac->buf_len;
  

• tasklet_schedule(&tdmac->tasklet);
  

• return IRQ_HANDLED;
  

• } else

• return IRQ_NONE;
  

+}

+static irqreturn_t mmp_tdma_int_handler(int irq, void *dev_id) +{

• struct mmp_tdma_device *tdev = dev_id;
• int i, ret;
• int irq_num = 0;
• for (i = 0; i < TDMA_CHANNEL_NUM; i++) {

• struct mmp_tdma_chan *tdmac = tdev->tdmac[i];
  

• ret = mmp_tdma_chan_handler(irq, tdmac);
  

• if (ret == IRQ_HANDLED)
  

• 	irq_num++;
  

• }
• if (irq_num)

• return IRQ_HANDLED;
  

• else

• return IRQ_NONE;
  

+}

+static void dma_do_tasklet(unsigned long data) +{

• struct mmp_tdma_chan *tdmac = (struct mmp_tdma_chan *)data;
• if (tdmac->desc.callback)

• tdmac->desc.callback(tdmac->desc.callback_param);
  

+}

+static void mmp_tdma_free_descriptor(struct mmp_tdma_chan *tdmac) +{

• struct gen_pool *gpool;
• int size = tdmac->desc_num * sizeof(struct mmp_tdma_desc);
• gpool = sram_get_gpool("asram");
• if (tdmac->desc_arr)

• gen_pool_free(gpool, (unsigned long)tdmac->desc_arr,
  

• 		size);
  

• tdmac->desc_arr = NULL;
• return;

+}

+static dma_cookie_t mmp_tdma_tx_submit(struct dma_async_tx_descriptor *tx) +{

• struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(tx->chan);
• mmp_tdma_chan_set_desc(tdmac, tdmac->desc_arr_phys);

This seems odd. In submit you are supposed to move this to your pending list. Btw where is the .issue_pending handler?

• return 0;

+}

+static int mmp_tdma_alloc_chan_resources(struct dma_chan *chan) +{

• struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(chan);
• int ret;
• dev_dbg(tdmac->dev, "%s: enter\n", __func__);
• dma_async_tx_descriptor_init(&tdmac->desc, chan);
• tdmac->desc.tx_submit = mmp_tdma_tx_submit;
• if (tdmac->irq) {

• ret = devm_request_irq(tdmac->dev, tdmac->irq,
  

• 	mmp_tdma_chan_handler, IRQF_DISABLED, "tdma", tdmac);
  

• if (ret)
  

• 	goto err_request_irq;
  

• }
• return 0;

NO. This is supposed to return the number of descriptors allocated.

+err_request_irq:

• mmp_tdma_free_descriptor(tdmac);
• return ret;

+}

+static void mmp_tdma_free_chan_resources(struct dma_chan *chan) +{

• struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(chan);
• dev_dbg(tdmac->dev, "%s: enter\n", __func__);
• if (tdmac->irq)

• devm_free_irq(tdmac->dev, tdmac->irq, tdmac);
  

• mmp_tdma_disable_chan(tdmac);

channel should be already disabled, why do you need this here?

• mmp_tdma_free_descriptor(tdmac);
• return;

+}

+static struct dma_async_tx_descriptor *mmp_tdma_prep_slave_sg(

• struct dma_chan *chan, struct scatterlist *sgl,
  

• unsigned int sg_len, enum dma_transfer_direction direction,
  

• unsigned long flags, void *context)
  

+{

• /*

• * This operation is not supported on the TDMA controller
  

• *
  

• * However, we need to provide the function pointer to allow the
  

• * device_control() method to work.
  

• */
  

• return NULL;

+}

Pls remove if not supported

+static int mmp_tdma_alloc_descriptor(struct mmp_tdma_chan *tdmac) +{

• struct gen_pool *gpool;
• int size = tdmac->desc_num * sizeof(struct mmp_tdma_desc);
• dev_dbg(tdmac->dev, "%s: enter\n", __func__);
• gpool = sram_get_gpool("asram");
• if (!gpool)

• return -ENOMEM;
  

• tdmac->desc_arr = (void *)gen_pool_alloc(gpool, size);
• if (!tdmac->desc_arr)

• return -ENOMEM;
  

• tdmac->desc_arr_phys = gen_pool_virt_to_phys(gpool,

• 	(unsigned long)tdmac->desc_arr);
  

• return 0;

this needs fix

+}

+static struct dma_async_tx_descriptor *mmp_tdma_prep_dma_cyclic(

• struct dma_chan *chan, dma_addr_t dma_addr, size_t buf_len,
  

• size_t period_len, enum dma_transfer_direction direction,
  

• void *context)
  

+{

• struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(chan);
• int num_periods = buf_len / period_len;
• int i = 0, buf = 0;
• int ret;
• if (tdmac->status != DMA_SUCCESS)

• return NULL;
  

• if (period_len > TDMA_MAX_XFER_BYTES) {

• dev_err(tdmac->dev,
  

• 		"maximum period size exceeded: %d > %d\n",
  

• 		period_len, TDMA_MAX_XFER_BYTES);
  

• goto err_out;
  

• }
• tdmac->status = DMA_IN_PROGRESS;

???

• tdmac->desc_num = num_periods;
• ret = mmp_tdma_alloc_descriptor(tdmac);
• if (ret < 0)

• goto err_out;
  

• while (buf < buf_len) {

• struct mmp_tdma_desc *desc = &tdmac->desc_arr[i];
  

what if i call prepare twice on the same channel? Better way would to manage a descriptor list, see other drivers for examples.

• if (i + 1 == num_periods)
  

• 	desc->nxt_desc = tdmac->desc_arr_phys;
  

• else
  

• 	desc->nxt_desc = tdmac->desc_arr_phys +
  

• 		sizeof(*desc) * (i + 1);
  

pls use kernel link list, it is provided to you so that you dont have to do above.

• if (direction == DMA_MEM_TO_DEV) {
  

• 	desc->src_addr = dma_addr;
  

• 	desc->dst_addr = tdmac->dev_addr;
  

• } else {
  

• 	desc->src_addr = tdmac->dev_addr;
  

• 	desc->dst_addr = dma_addr;
  

• }
  

• desc->byte_cnt = period_len;
  

• dma_addr += period_len;
  

• buf += period_len;
  

• i++;
  

• }
• tdmac->buf_len = buf_len;
• tdmac->period_len = period_len;
• tdmac->pos = 0;
• return &tdmac->desc;

+err_out:

• tdmac->status = DMA_ERROR;
• return NULL;

+}

+static int mmp_tdma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,

• unsigned long arg)
  

+{

• struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(chan);
• struct dma_slave_config *dmaengine_cfg = (void *)arg;
• int ret = 0;
• switch (cmd) {
• case DMA_TERMINATE_ALL:

• mmp_tdma_disable_chan(tdmac);
  

• break;
  

• case DMA_PAUSE:

• mmp_tdma_pause_chan(tdmac);
  

• break;
  

• case DMA_RESUME:

• mmp_tdma_resume_chan(tdmac);
  

• break;
  

• case DMA_SLAVE_CONFIG:

• if (dmaengine_cfg->direction == DMA_DEV_TO_MEM) {
  

• 	tdmac->dev_addr = dmaengine_cfg->src_addr;
  

• 	tdmac->burst_sz = dmaengine_cfg->src_maxburst;
  

• } else {
  

• 	tdmac->dev_addr = dmaengine_cfg->dst_addr;
  

• 	tdmac->burst_sz = dmaengine_cfg->dst_maxburst;
  

• }
  

• tdmac->dir = dmaengine_cfg->direction;
  

• return mmp_tdma_config_chan(tdmac);
  

• default:

• ret = -ENOSYS;
  

• }
• return ret;

+}

+static enum dma_status mmp_tdma_tx_status(struct dma_chan *chan,

• 	dma_cookie_t cookie, struct dma_tx_state *txstate)
  

+{

• struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(chan);
• dma_set_residue(txstate, tdmac->buf_len - tdmac->pos);
• return tdmac->status;

+}

+static void mmp_tdma_issue_pending(struct dma_chan *chan) +{

• struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(chan);
• mmp_tdma_enable_chan(tdmac);

can you queue the descriptors here? That was purpose to have separate issue pending and submit.

+}

+static int __devexit mmp_tdma_remove(struct platform_device *pdev) +{

• struct mmp_tdma_device *tdev = platform_get_drvdata(pdev);
• dma_async_device_unregister(&tdev->device);
• return 0;

+}

+static int __devinit mmp_tdma_chan_init(struct mmp_tdma_device *tdev,

• 				int idx, int irq, int type)
  

+{

• struct mmp_tdma_chan *tdmac;
• if (idx >= TDMA_CHANNEL_NUM) {

• dev_err(tdev->dev, "too many channels for device!\n");
  

• return -EINVAL;
  

• }
• /* alloc channel */
• tdmac = devm_kzalloc(tdev->dev, sizeof(*tdmac), GFP_KERNEL);
• if (!tdmac) {

• dev_err(tdev->dev, "no free memory for DMA channels!\n");
  

• return -ENOMEM;
  

• }
• if (irq)

• tdmac->irq = irq + idx;
  

• tdmac->dev = tdev->dev;
• tdmac->chan.device = &tdev->device;
• tdmac->idx = idx;
• tdmac->type = type;
• tdmac->reg_base = (unsigned long)tdev->base + idx * 4;
• tdmac->status = DMA_SUCCESS;
• tdev->tdmac[tdmac->idx] = tdmac;
• tasklet_init(&tdmac->tasklet, dma_do_tasklet, (unsigned long)tdmac);
• /* add the channel to tdma_chan list */
• list_add_tail(&tdmac->chan.device_node,

• 	&tdev->device.channels);
  

• return 0;

+}

+static int __devinit mmp_tdma_probe(struct platform_device *pdev) +{

• const struct platform_device_id *id = platform_get_device_id(pdev);
• enum mmp_tdma_type type = id->driver_data;
• struct mmp_tdma_device *tdev;
• struct resource *iores;
• int i, ret;
• int irq = 0;
• int chan_num = TDMA_CHANNEL_NUM;
• /* always have couple channels */
• tdev = devm_kzalloc(&pdev->dev, sizeof(*tdev), GFP_KERNEL);
• if (!tdev)

• return -ENOMEM;
  

• tdev->dev = &pdev->dev;
• iores = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
• if (!iores)

• return -EINVAL;
  

• if (resource_size(iores) != chan_num)

• tdev->irq = iores->start;
  

• else

• irq = iores->start;
  

• iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
• if (!iores)

• return -EINVAL;
  

• tdev->base = devm_request_and_ioremap(&pdev->dev, iores);
• if (!tdev->base)

• return -EADDRNOTAVAIL;
  

• if (tdev->irq) {

• ret = devm_request_irq(&pdev->dev, tdev->irq,
  

• 	mmp_tdma_int_handler, IRQF_DISABLED, "tdma", tdev);
  

• if (ret)
  

• 	return ret;
  

• }
• dma_cap_set(DMA_SLAVE, tdev->device.cap_mask);
• dma_cap_set(DMA_CYCLIC, tdev->device.cap_mask);
• INIT_LIST_HEAD(&tdev->device.channels);
• /* initialize channel parameters */
• for (i = 0; i < chan_num; i++) {

• ret = mmp_tdma_chan_init(tdev, i, irq, type);
  

• if (ret)
  

• 	return ret;
  

• }
• tdev->device.dev = &pdev->dev;
• tdev->device.device_alloc_chan_resources =

• 			mmp_tdma_alloc_chan_resources;
  

• tdev->device.device_free_chan_resources =

• 			mmp_tdma_free_chan_resources;
  

• tdev->device.device_prep_slave_sg = mmp_tdma_prep_slave_sg;
• tdev->device.device_prep_dma_cyclic = mmp_tdma_prep_dma_cyclic;
• tdev->device.device_tx_status = mmp_tdma_tx_status;
• tdev->device.device_issue_pending = mmp_tdma_issue_pending;
• tdev->device.device_control = mmp_tdma_control;
• tdev->device.copy_align = TDMA_ALIGNMENT;
• dma_set_mask(&pdev->dev, DMA_BIT_MASK(64));
• platform_set_drvdata(pdev, tdev);
• ret = dma_async_device_register(&tdev->device);
• if (ret) {

• dev_err(tdev->device.dev, "unable to register\n");
  

• return ret;
  

• }
• dev_info(tdev->device.dev, "initialized\n");
• return 0;

+}

+static const struct platform_device_id mmp_tdma_id_table[] = {

• { "mmp-adma", MMP_AUD_TDMA },
• { "pxa910-squ", PXA910_SQU },
• { },

+};

+static struct platform_driver mmp_tdma_driver = {

• .driver = {

• .name	= "mmp-tdma",
  

• .owner  = THIS_MODULE,
  

• },
• .id_table = mmp_tdma_id_table,
• .probe = mmp_tdma_probe,
• .remove = __devexit_p(mmp_tdma_remove),

+};

+module_platform_driver(mmp_tdma_driver);

+MODULE_DESCRIPTION("MMP Two-Channel DMA Driver"); +MODULE_LICENSE("GPL");

AUTHOR, ALIAS too pls

diff --git a/include/linux/platform_data/mmp_dma.h b/include/linux/platform_data/mmp_dma.h new file mode 100644 index 0000000..4e21cf9 --- /dev/null +++ b/include/linux/platform_data/mmp_dma.h @@ -0,0 +1,20 @@ +/*

• • MMP Platform DMA Management
• • Copyright (c) 2011 Marvell Semiconductors 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.
• */

+#ifndef MMP_DMA_H +#define MMP_DMA_H

+struct mmp_tdma_data {

• u32 bus_size;
• u32 pack_mod;

+};

+#endif /* MMP_DMA_H */

why do you need separate header for this?