Subject: [PATCH 1/6] soc: qcom: gsbi: Add support for ADM CRCI muxing

From: [email-masked] (Stephen Boyd)
Date: Wed, 28 Jan 2015 18:11:50 -0800

On 01/27, Andy Gross wrote:
> This patch adds automatic configuration for the ADM CRCI muxing required to
> support DMA operations for GSBI clients.  The GSBI mode and instance determine
> the correct TCSR ADM CRCI MUX value that must be programmed so that the DMA
> works properly.
> 
> Signed-off-by: Andy Gross <[email-masked]>
> ---
>  .../devicetree/bindings/soc/qcom/qcom,gsbi.txt     |   17 ++-
>  drivers/soc/qcom/Kconfig                           |    1 +
>  drivers/soc/qcom/qcom_gsbi.c                       |  148 +++++++++++++++++++-
>  3 files changed, 158 insertions(+), 8 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/soc/qcom/qcom,gsbi.txt b/Documentation/devicetree/bindings/soc/qcom/qcom,gsbi.txt
> index 4ce24d4..39eea8a 100644
> --- a/Documentation/devicetree/bindings/soc/qcom/qcom,gsbi.txt
> +++ b/Documentation/devicetree/bindings/soc/qcom/qcom,gsbi.txt
> @@ -6,12 +6,18 @@ configuration settings.  The mode setting will govern the input/output mode of
>  the 4 GSBI IOs.
>  
>  Required properties:
> -- compatible: must contain "qcom,gsbi-v1.0.0" for APQ8064/IPQ8064
> +- compatible:	Should contain:
> +		"qcom,gsbi-ipq8064" for IPQ8064
> +		"qcom,gsbi-apq8064" for APQ8064
> +		"qcom,gsbi-msm8960" for MSM8960
> +		"qcom,gsbi-msm8660" for MSM8660

Hopefully this is not necessary, but if it is we should leave the
old compatible here and say it's deprecated or something.

>  - reg: Address range for GSBI registers
>  - clocks: required clock
>  - clock-names: must contain "iface" entry
>  - qcom,mode : indicates MUX value for configuration of the serial interface.
>    Please reference dt-bindings/soc/qcom,gsbi.h for valid mux values.
> +- qcom,gsbi-num: indicates GSBI instance number

Why not use DT aliases for this? Then other drivers or more
generic code can search for a gsbiN alias for the particular gsbi
node. No qcom specific property.

> +- syscon-tcsr: indicates phandle of TCSR syscon node

Make this optional but required if any child nodes use dma?

>  
>  Optional properties:
>  - qcom,crci : indicates CRCI MUX value for QUP CRCI ports.  Please reference

> diff --git a/drivers/soc/qcom/qcom_gsbi.c b/drivers/soc/qcom/qcom_gsbi.c
> index 729425d..c7a22b5 100644
> --- a/drivers/soc/qcom/qcom_gsbi.c
> +++ b/drivers/soc/qcom/qcom_gsbi.c
>  
>  struct gsbi_info {
>  	struct clk *hclk;
>  	u32 mode;
>  	u32 crci;
> +	struct regmap *tcsr;
> +};
> +
> +static const struct of_device_id gsbi_dt_match[] = {
> +	{ .compatible = "qcom,gsbi-v1.0.0", .data = NULL},
> +	{ .compatible = "qcom,gsbi-ipq8064", .data = &config_ipq8064},
> +	{ .compatible = "qcom,gsbi-apq8064", .data = &config_apq8064},
> +	{ .compatible = "qcom,gsbi-msm8960", .data = &config_msm8960},
> +	{ .compatible = "qcom,gsbi-msm8660", .data = &config_msm8660},
> +	{ },
>  };
> +MODULE_DEVICE_TABLE(of, gsbi_dt_match);
>  
>  static int gsbi_probe(struct platform_device *pdev)
>  {
>  	struct device_node *node = pdev->dev.of_node;
> +	const struct of_device_id *match;
>  	struct resource *res;
>  	void __iomem *base;
>  	struct gsbi_info *gsbi;
> +	u32 gsbi_num, i, val;

i should be int

> +	struct crci_config *config;

const?

>  
>  	gsbi = devm_kzalloc(&pdev->dev, sizeof(*gsbi), GFP_KERNEL);
>  
> @@ -45,6 +152,20 @@ static int gsbi_probe(struct platform_device *pdev)
>  	if (IS_ERR(base))
>  		return PTR_ERR(base);
>  
> +	gsbi->tcsr = syscon_regmap_lookup_by_phandle(node, "syscon-tcsr");
> +	if (IS_ERR(gsbi->tcsr))
> +		return -EINVAL;
> +
> +	if (of_property_read_u32(node, "qcom,gsbi-num", &gsbi_num)) {
> +		dev_err(&pdev->dev, "missing gsbi instance number\n");
> +		return -EINVAL;
> +	}

As said before, aliases would do the job the same and not require
some qcom specific property.

> +
> +	if (!gsbi_num || gsbi_num > MAX_GSBI) {
> +		dev_err(&pdev->dev, "invalid gsbi number\n");
> +		return -EINVAL;
> +	}
> +
>  	if (of_property_read_u32(node, "qcom,mode", &gsbi->mode)) {
>  		dev_err(&pdev->dev, "missing mode configuration\n");
>  		return -EINVAL;
> @@ -64,6 +185,26 @@ static int gsbi_probe(struct platform_device *pdev)
>  	writel_relaxed((gsbi->mode << GSBI_PROTOCOL_SHIFT) | gsbi->crci,
>  				base + GSBI_CTRL_REG);
>  
> +	/*
> +	 * modify tcsr to reflect mode and ADM CRCI mux
> +	 * Each gsbi contains a pair of bits, one for RX and one for TX
> +	 * SPI mode requires both bits cleared, otherwise they are set
> +	 */
> +	match = of_match_node(gsbi_dt_match, node);

Why not match the config to the TCSR compatible string? Wouldn't
that more accurately reflect that we need to set different bits
depending on which type of TCSR we're using? The version of GSBI
hardware is not actually changing in every different SoC so I
don't see why we want to change the compatible there just because
the TCSR register layout changed.

> +	config = (struct crci_config *)match->data;

Cast shouldn't be necessary if config is const?

> +
> +	if (config)
> +		for (i = 0; i < config->num_rows; i++) {
> +			if (gsbi->mode == GSBI_PROT_SPI)

Doesn't I2C need the same treatment (anything in QUP really)?
Maybe the logic could be changed to check for gsbi->crci ==
GSBI_CRCI_QUP?

> +				val = config->array[i*MAX_GSBI + gsbi_num - 1];
> +			else
> +				val = 0;
> +
> +			regmap_update_bits(gsbi->tcsr,
> +				TCSR_ADM_CRCI_BASE + 0x4*i,
> +				config->array[i*MAX_GSBI + gsbi_num - 1], val);
> +		}
> +
>  	/* make sure the gsbi control write is not reordered */
>  	wmb();
>  

-- 
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