Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit c5f43a1e authored by Bhalchandra Gajare's avatar Bhalchandra Gajare Committed by Gerrit - the friendly Code Review server
Browse files

ASoC: wcd-spi: add SPI bus arbitration logic 



On some platforms, WCD SPI bus can be shared with other processors
(ex: sensor processor). In such cases, there is need for software
to arbitrate the bus control. Add functionality to perform SPI bus
arbitration.

Change-Id: I7df933f55ac5035a55173a04e74b74f7af1f7ece
Signed-off-by: default avatarBhalchandra Gajare <gajare@codeaurora.org>
parent e039f16f

asoc/codecs/wcd-spi.c

+92 −0
Original line number Diff line number Diff line
@@ -14,8 +14,10 @@ 
#include <linux/regmap.h>

#include <linux/component.h>

#include <linux/ratelimit.h>

#include <linux/platform_device.h>

#include <sound/wcd-dsp-mgr.h>

#include <sound/wcd-spi.h>

#include <soc/wcd-spi-ac.h>

#include "wcd-spi-registers.h"



/* Byte manipulations */
@@ -157,6 +159,8 @@ struct wcd_spi_priv { 
	/* DMA handles for transfer buffers */

	dma_addr_t tx_dma;

	dma_addr_t rx_dma;

	/* Handle to child (qmi client) device */

	struct device *ac_dev;

};



enum xfer_request {
@@ -567,6 +571,19 @@ static int wcd_spi_clk_enable(struct spi_device *spi) 
	int ret;

	u32 rd_status = 0;



	/* Get the SPI access first */

	if (wcd_spi->ac_dev) {

		ret = wcd_spi_access_ctl(wcd_spi->ac_dev,

					 WCD_SPI_ACCESS_REQUEST,

					 WCD_SPI_AC_DATA_TRANSFER);

		if (ret) {

			dev_err(&spi->dev,

				"%s: Can't get spi access, err = %d\n",

				__func__, ret);

			return ret;

		}

	}



	ret = wcd_spi_cmd_nop(spi);

	if (ret < 0) {

		dev_err(&spi->dev, "%s: NOP1 failed, err = %d\n",
@@ -620,6 +637,17 @@ static int wcd_spi_clk_disable(struct spi_device *spi) 
	 */

	clear_bit(WCD_SPI_CLK_STATE_ENABLED, &wcd_spi->status_mask);



	/* once the clock is released, SPI access can be released as well */

	if (wcd_spi->ac_dev) {

		ret = wcd_spi_access_ctl(wcd_spi->ac_dev,

					 WCD_SPI_ACCESS_RELEASE,

					 WCD_SPI_AC_DATA_TRANSFER);

		if (ret)

			dev_err(&spi->dev,

				"%s: SPI access release failed, err = %d\n",

				__func__, ret);

	}



	return ret;

}
@@ -944,6 +972,18 @@ static int wdsp_spi_event_handler(struct device *dev, void *priv_data, 
		__func__, event);



	switch (event) {

	case WDSP_EVENT_PRE_SHUTDOWN:

		if (wcd_spi->ac_dev) {

			ret = wcd_spi_access_ctl(wcd_spi->ac_dev,

					 WCD_SPI_ACCESS_REQUEST,

					 WCD_SPI_AC_REMOTE_DOWN);

			if (ret)

				dev_err(&spi->dev,

					"%s: request access failed %d\n",

					__func__, ret);

		}

		break;



	case WDSP_EVENT_POST_SHUTDOWN:

		cancel_delayed_work_sync(&wcd_spi->clk_dwork);

		WCD_SPI_MUTEX_LOCK(spi, wcd_spi->clk_mutex);
@@ -953,6 +993,18 @@ static int wdsp_spi_event_handler(struct device *dev, void *priv_data, 
		WCD_SPI_MUTEX_UNLOCK(spi, wcd_spi->clk_mutex);

		break;



	case WDSP_EVENT_POST_BOOTUP:

		if (wcd_spi->ac_dev) {

			ret = wcd_spi_access_ctl(wcd_spi->ac_dev,

					 WCD_SPI_ACCESS_RELEASE,

					 WCD_SPI_AC_REMOTE_DOWN);

			if (ret)

				dev_err(&spi->dev,

					"%s: release access failed %d\n",

					__func__, ret);

		}

		break;



	case WDSP_EVENT_PRE_DLOAD_CODE:

	case WDSP_EVENT_PRE_DLOAD_DATA:

		ret = wcd_spi_clk_ctrl(spi, WCD_SPI_CLK_ENABLE,
@@ -1299,10 +1351,50 @@ static struct regmap_config wcd_spi_regmap_cfg = { 
	.readable_reg = wcd_spi_is_readable_reg,

};



static int wcd_spi_add_ac_dev(struct device *dev,

			       struct device_node *node)

{

	struct spi_device *spi = to_spi_device(dev);

	struct wcd_spi_priv *wcd_spi = spi_get_drvdata(spi);

	struct platform_device *pdev;

	int ret = 0;



	pdev = platform_device_alloc("wcd-spi-ac", -1);

	if (IS_ERR_OR_NULL(pdev)) {

		ret = PTR_ERR(pdev);

		dev_err(dev, "%s: pdev alloc failed, ret = %d\n",

			__func__, ret);

		return ret;

	}



	pdev->dev.parent = dev;

	pdev->dev.of_node = node;



	ret = platform_device_add(pdev);

	if (ret) {

		dev_err(dev, "%s: pdev add failed, ret = %d\n",

			__func__, ret);

		goto dealloc_pdev;

	}



	wcd_spi->ac_dev = &pdev->dev;

	return 0;



dealloc_pdev:

	platform_device_put(pdev);

	return ret;

}



static int wdsp_spi_init(struct device *dev, void *priv_data)

{

	struct spi_device *spi = to_spi_device(dev);

	int ret;

	struct device_node *node;



	for_each_child_of_node(dev->of_node, node) {

		if (!strcmp(node->name, "wcd_spi_ac"))

			wcd_spi_add_ac_dev(dev, node);

	}



	ret = wcd_spi_init(spi);

	if (ret < 0)