RE: [PATCH v2 1/2] i2c: qup: add ACPI support

["Sricharan" <sricharan@codeaurora.org>]

Hi,

> Add support to get the device parameters from ACPI. Assume that the clocks
> are managed by firmware.
> 
> Signed-off-by: Naveen Kaje <nkaje@codeaurora.org>
> ---
>  drivers/i2c/busses/i2c-qup.c | 59 +++++++++++++++++++++++++++++++++---
> --------
>  1 file changed, 44 insertions(+), 15 deletions(-)
> 
<.snip>

> +/* Default values. Use these if FW query fails */ #define
> +DEFAULT_CLK_FREQ 100000 #define DEFAULT_SRC_CLK 20000000
> +
>  struct qup_i2c_block {
>  	int	count;
>  	int	pos;
> @@ -1360,8 +1365,8 @@ static int qup_i2c_probe(struct platform_device
> *pdev)
>  	struct resource *res;
>  	u32 io_mode, hw_ver, size;
>  	int ret, fs_div, hs_div;
> -	int src_clk_freq;
> -	u32 clk_freq = 100000;
> +	u32 src_clk_freq = 0;
> +	u32 clk_freq = 0;
>  	int blocks;
> 
>  	qup = devm_kzalloc(&pdev->dev, sizeof(*qup), GFP_KERNEL); @@ -
> 1372,7 +1377,12 @@ static int qup_i2c_probe(struct platform_device *pdev)
>  	init_completion(&qup->xfer);
>  	platform_set_drvdata(pdev, qup);
> 
> -	of_property_read_u32(node, "clock-frequency", &clk_freq);
> +	ret = device_property_read_u32(qup->dev, "clock-frequency",
> &clk_freq);
> +	if (ret) {
> +		dev_warn(qup->dev, "using default clock-frequency %d",
> +			DEFAULT_CLK_FREQ);
> +		clk_freq = DEFAULT_CLK_FREQ;
> +	}
> 
>  	if (of_device_is_compatible(pdev->dev.of_node, "qcom,i2c-qup-
> v1.1.1")) {
>  		qup->adap.algo = &qup_i2c_algo;
> @@ -1454,20 +1464,31 @@ nodma:
>  		return qup->irq;
>  	}
> 
> -	qup->clk = devm_clk_get(qup->dev, "core");
> -	if (IS_ERR(qup->clk)) {
> -		dev_err(qup->dev, "Could not get core clock\n");
> -		return PTR_ERR(qup->clk);
> -	}
> +	if (ACPI_HANDLE(qup->dev)) {
> +		ret = device_property_read_u32(qup->dev,
> +				"src-clock-hz", &src_clk_freq);
> +		if (ret) {
> +			dev_warn(qup->dev, "using default src-clock-hz %d",
> +				DEFAULT_SRC_CLK);
> +			src_clk_freq = DEFAULT_SRC_CLK;
> +		}
> +		ACPI_COMPANION_SET(&qup->adap.dev,
> ACPI_COMPANION(qup->dev));
> +	} else {
> +		qup->clk = devm_clk_get(qup->dev, "core");
> +		if (IS_ERR(qup->clk)) {
> +			dev_err(qup->dev, "Could not get core clock\n");
> +			return PTR_ERR(qup->clk);
> +		}
> 
> -	qup->pclk = devm_clk_get(qup->dev, "iface");
> -	if (IS_ERR(qup->pclk)) {
> -		dev_err(qup->dev, "Could not get iface clock\n");
> -		return PTR_ERR(qup->pclk);
> +		qup->pclk = devm_clk_get(qup->dev, "iface");
> +		if (IS_ERR(qup->pclk)) {
> +			dev_err(qup->dev, "Could not get iface clock\n");
> +			return PTR_ERR(qup->pclk);
> +		}
> +		qup_i2c_enable_clocks(qup);
> +		src_clk_freq = clk_get_rate(qup->clk);
>  	}
> 
> -	qup_i2c_enable_clocks(qup);
> -
>  	/*
>  	 * Bootloaders might leave a pending interrupt on certain QUP's,
>  	 * so we reset the core before registering for interrupts.
> @@ -1514,7 +1535,6 @@ nodma:
>  	size = QUP_INPUT_FIFO_SIZE(io_mode);
>  	qup->in_fifo_sz = qup->in_blk_sz * (2 << size);
> 
> -	src_clk_freq = clk_get_rate(qup->clk);
>  	fs_div = ((src_clk_freq / clk_freq) / 2) - 3;
>  	hs_div = 3;
>  	qup->clk_ctl = (hs_div << 8) | (fs_div & 0xff); @@ -1639,6 +1659,14
> @@ static const struct of_device_id qup_i2c_dt_match[] = {  };
> MODULE_DEVICE_TABLE(of, qup_i2c_dt_match);
> 
> +#if IS_ENABLED(CONFIG_ACPI)
> +static const struct acpi_device_id qup_i2c_acpi_match[] = {
> +	{ "QCOM8010"},
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(acpi, qup_i2c_acpi_ids); #endif
> +
>  static struct platform_driver qup_i2c_driver = {
>  	.probe  = qup_i2c_probe,
>  	.remove = qup_i2c_remove,
> @@ -1646,6 +1674,7 @@ static struct platform_driver qup_i2c_driver = {
>  		.name = "i2c_qup",
>  		.pm = &qup_i2c_qup_pm_ops,
>  		.of_match_table = qup_i2c_dt_match,
> +		.acpi_match_table = ACPI_PTR(qup_i2c_acpi_match),
>  	},
>  };
> 
 Reviewed-by: sricharan@codeaurora.org

Regards,
 Sricharan