Re: [PATCH 2/5] soundwire: qcom: add support for mmio soundwire devices

On 6/8/20 3:43 PM, Jonathan Marek wrote:

Adds support for qcom soundwire devices with memory mapped IO registers.

'device' is an ambiguous term for SoundWire.

Seems to me this is a SoundWire Master device directly accessed with mmio registers instead of over a SLIMbus link?

Signed-off-by: Jonathan Marek jonathan@marek.ca

drivers/soundwire/qcom.c | 25 +++++++++++++++++++++++-- 1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/drivers/soundwire/qcom.c b/drivers/soundwire/qcom.c index f38d1fd3679f..628747df1c75 100644 --- a/drivers/soundwire/qcom.c +++ b/drivers/soundwire/qcom.c @@ -90,6 +90,7 @@ struct qcom_swrm_ctrl { struct sdw_bus bus; struct device *dev; struct regmap *regmap;

• void __iomem *mmio; struct completion *comp; struct work_struct slave_work; /* read/write lock */

@@ -154,6 +155,20 @@ static int qcom_swrm_ahb_reg_write(struct qcom_swrm_ctrl *ctrl, return SDW_CMD_OK; }

+static int qcom_swrm_cpu_reg_read(struct qcom_swrm_ctrl *ctrl, int reg,

• 		  u32 *val)
  

+{

• *val = readl(ctrl->mmio + reg);
• return SDW_CMD_OK;

+}

+static int qcom_swrm_cpu_reg_write(struct qcom_swrm_ctrl *ctrl, int reg,

• 		   int val)
  

+{

• writel(val, ctrl->mmio + reg);
• return SDW_CMD_OK;

+}

• static int qcom_swrm_cmd_fifo_wr_cmd(struct qcom_swrm_ctrl *ctrl, u8 cmd_data, u8 dev_addr, u16 reg_addr) {

@@ -746,6 +761,7 @@ static int qcom_swrm_probe(struct platform_device *pdev) struct sdw_master_prop *prop; struct sdw_bus_params *params; struct qcom_swrm_ctrl *ctrl;

• struct resource *res; int ret; u32 val;

@@ -760,8 +776,13 @@ static int qcom_swrm_probe(struct platform_device *pdev) if (!ctrl->regmap) return -EINVAL; } else {

• /* Only WCD based SoundWire controller is supported */
  

• return -ENOTSUPP;
  

I would move patch4 before this one, and add the functionality *after* removing the SLIMbus dependency.

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

• ctrl->reg_read = qcom_swrm_cpu_reg_read;
  

• ctrl->reg_write = qcom_swrm_cpu_reg_write;
  

• ctrl->mmio = devm_ioremap_resource(dev, res);
  

• if (IS_ERR(ctrl->mmio))
  

• 	return PTR_ERR(ctrl->mmio);
  

maybe deal with the resource checks before setting callbacks?

There are quite a few drivers who do things this way:

clk/qcom/common.c- res = platform_get_resource(pdev, IORESOURCE_MEM, 0); clk/qcom/common.c: base = devm_ioremap_resource(dev, res); --

}

ctrl->irq = of_irq_get(dev->of_node, 0);