Re: [alsa-devel] [PATCH v2 2/6] ASoC: Davinci: McBSP: add device tree support for McBSP

On 04/11/16 14:45, Petr Kulhavy wrote:

This adds DT support for the TI DA8xx/OMAP-L1x/AM17xx/AM18xx McBSP driver.

Signed-off-by: Petr Kulhavy petr@barix.com

v1: initial v2: remove "-audio" postfix from the compatible string of_match_table renamed consistently with the rest of the file (davinci_i2s_match) "channel-combine" property removed devicetree DMA configuration in probe simplified

sound/soc/davinci/Kconfig | 6 ++- sound/soc/davinci/davinci-i2s.c | 116 +++++++++++++++++++++++++++++++--------- 2 files changed, 95 insertions(+), 27 deletions(-)

diff --git a/sound/soc/davinci/Kconfig b/sound/soc/davinci/Kconfig index 50ca291cc225..6b732d8e5896 100644 --- a/sound/soc/davinci/Kconfig +++ b/sound/soc/davinci/Kconfig @@ -16,7 +16,11 @@ config SND_EDMA_SOC - DRA7xx family

config SND_DAVINCI_SOC_I2S

• tristate

• tristate "DaVinci Multichannel Buffered Serial Port (McBSP) support"
• depends on SND_EDMA_SOC
• help

•  Say Y or M here if you want to have support for McBSP IP found in
  

•  Texas Instruments DaVinci DA850 SoCs.
  
  

config SND_DAVINCI_SOC_MCASP tristate "Multichannel Audio Serial Port (McASP) support" diff --git a/sound/soc/davinci/davinci-i2s.c b/sound/soc/davinci/davinci-i2s.c index ec98548a5fc9..a3f82d1a73dc 100644 --- a/sound/soc/davinci/davinci-i2s.c +++ b/sound/soc/davinci/davinci-i2s.c @@ -4,9 +4,15 @@

• Author: Vladimir Barinov, vbarinov@embeddedalley.com
• Copyright: (C) 2007 MontaVista Software, Inc., source@mvista.com

• • DT support (c) 2016 Petr Kulhavy, Barix AG petr@barix.com

• • based on davinci-mcasp.c DT support
    

• • 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.
• • TODO:
• • on DA850 implement HW FIFOs instead of DMA into DXR and DRR registers
  */

#include <linux/init.h> @@ -648,15 +654,62 @@ static const struct snd_soc_component_driver davinci_i2s_component = { .name = "davinci-i2s", };

+static struct snd_platform_data* +davinci_i2s_set_pdata_from_of(struct platform_device *pdev)

It is a bit misleading function name, would be better to name it as davinci_i2s_get_pdata()

as it will fetch the legacy pdata or craft one when booting with DT.

+{

• struct snd_platform_data *pdata = NULL;
• struct device_node *np;
• if (!IS_ENABLED(CONFIG_OF) || !pdev->dev.of_node)

• return dev_get_platdata(&pdev->dev);
  

• pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
• if (!pdata)

• return ERR_PTR(-ENOMEM);
  

• np = pdev->dev.of_node;

???

• /* parse properties here */
• /*

• * pdata->clk_input_pin is deliberately not exported to DT
  

• * and the default value of the clk_input_pin is MCBSP_CLKR.
  

• * The value MCBSP_CLKS makes no sense as it turns the CPU
  

• * to a bit clock master in the SND_SOC_DAIFMT_CBM_CFS mode
  

• * where it should be bit clock slave!
  

• */
  

• return pdata;

+}

static int davinci_i2s_probe(struct platform_device *pdev) {

• struct snd_dmaengine_dai_dma_data *dma_data;
• struct snd_platform_data *pdata; struct davinci_mcbsp_dev *dev; struct resource *mem, *res; void __iomem *io_base; int *dma; int ret;

• mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);

• pdata = davinci_i2s_set_pdata_from_of(pdev);
• if (IS_ERR(pdata)) {

• dev_err(&pdev->dev, "Error populating platform data, err %ld\n",
  

• 	PTR_ERR(pdata));
  

• return PTR_ERR(pdata);
  

• }

The current driver does not use the pdata as far as I can see. Kind of strange. So now in DT boot you will allocate memory for the pdata, which is not used by the driver at all. I think we should implement the pdata handling in the driver first for the legacy mode, then probably having pdata allocated for DT case might make sense.

• mem = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mpu");
• if (!mem) {

• dev_warn(&pdev->dev,
  

• 	 "\"mpu\" mem resource not found, using index 0\n");
  

• mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  

• if (!mem) {
  

• 	dev_err(&pdev->dev, "no mem resource?\n");
  

• 	return -ENODEV;
  

• }
  

• }
• io_base = devm_ioremap_resource(&pdev->dev, mem); if (IS_ERR(io_base)) return PTR_ERR(io_base);

@@ -666,39 +719,43 @@ static int davinci_i2s_probe(struct platform_device *pdev) if (!dev) return -ENOMEM;

• dev->clk = clk_get(&pdev->dev, NULL);

• if (IS_ERR(dev->clk))

• return -ENODEV;
  

• clk_enable(dev->clk);

• dev->base = io_base;

• dev->dma_data[SNDRV_PCM_STREAM_PLAYBACK].addr =

•    (dma_addr_t)(mem->start + DAVINCI_MCBSP_DXR_REG);
  

• dev->dma_data[SNDRV_PCM_STREAM_CAPTURE].addr =

•    (dma_addr_t)(mem->start + DAVINCI_MCBSP_DRR_REG);
  

• /* setup DMA, first TX, then RX */
• dma_data = &dev->dma_data[SNDRV_PCM_STREAM_PLAYBACK];
• dma_data->addr = (dma_addr_t)(mem->start + DAVINCI_MCBSP_DXR_REG);

• /* first TX, then RX */ res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
• if (!res) {

• dev_err(&pdev->dev, "no DMA resource\n");
  

• ret = -ENXIO;
  

• goto err_release_clk;
  

• if (res) {

• dma = &dev->dma_request[SNDRV_PCM_STREAM_PLAYBACK];
  

• *dma = res->start;
  

• dma_data->filter_data = dma;
  

• } else if (IS_ENABLED(CONFIG_OF) && pdev->dev.of_node) {

• dma_data->filter_data = "tx";
  

• } else {

• dev_err(&pdev->dev, "Missing DMA tx resource\n");
  

• return -ENODEV;
  

  }

• dma = &dev->dma_request[SNDRV_PCM_STREAM_PLAYBACK];
• *dma = res->start;
• dev->dma_data[SNDRV_PCM_STREAM_PLAYBACK].filter_data = dma;

• dma_data = &dev->dma_data[SNDRV_PCM_STREAM_CAPTURE];

• dma_data->addr = (dma_addr_t)(mem->start + DAVINCI_MCBSP_DRR_REG);

  res = platform_get_resource(pdev, IORESOURCE_DMA, 1);

• if (!res) {

• dev_err(&pdev->dev, "no DMA resource\n");
  

• ret = -ENXIO;
  

• goto err_release_clk;
  

• if (res) {

• dma = &dev->dma_request[SNDRV_PCM_STREAM_CAPTURE];
  

• *dma = res->start;
  

• dma_data->filter_data = dma;
  

• } else if (IS_ENABLED(CONFIG_OF) && pdev->dev.of_node) {

• dma_data->filter_data = "rx";
  

• } else {

• dev_err(&pdev->dev, "Missing DMA rx resource\n");
  

• return -ENODEV;
  

  }

• dma = &dev->dma_request[SNDRV_PCM_STREAM_CAPTURE];
• *dma = res->start;
• dev->dma_data[SNDRV_PCM_STREAM_CAPTURE].filter_data = dma;

• dev->clk = clk_get(&pdev->dev, NULL);

• if (IS_ERR(dev->clk))

• return -ENODEV;
  

• clk_enable(dev->clk);

  dev->dev = &pdev->dev; dev_set_drvdata(&pdev->dev, dev);

@@ -737,11 +794,18 @@ static int davinci_i2s_remove(struct platform_device *pdev) return 0; }

+static const struct of_device_id davinci_i2s_match[] = {

• { .compatible = "ti,da850-mcbsp" },
• {},

+}; +MODULE_DEVICE_TABLE(of, davinci_i2s_match);

static struct platform_driver davinci_mcbsp_driver = { .probe = davinci_i2s_probe, .remove = davinci_i2s_remove, .driver = { .name = "davinci-mcbsp",

• .of_match_table = of_match_ptr(davinci_i2s_match),
  

  },

};

The rest looks good to me.