Re: [PATCH v5 5/7] usb: dwc3: dwc3-octeon: Move node parsing into driver probe

[Thinh Nguyen <Thinh.Nguyen@synopsys.com>]

On Mon, Jul 31, 2023, Ladislav Michl wrote:
> From: Ladislav Michl <ladis@linux-mips.org>
> 
> Parse and verify device tree node first, then setup UCTL bridge
> using verified values. This avoids needless allocations
> in case DT misconfiguration was found in the middle of setup.
> 
> Signed-off-by: Ladislav Michl <ladis@linux-mips.org>
> ---
>  CHANGES:
>  - v2: if else block bracket according CodingStyle
>  - v3: more descriptive commit message, power gpio parsing in probe too,
>        checkpatch --strict passed
>  - v4: move changes unrelated to parsing move into separate patches
>  - v5: none
> 
>  drivers/usb/dwc3/dwc3-octeon.c | 135 +++++++++++++++------------------
>  1 file changed, 60 insertions(+), 75 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/dwc3-octeon.c b/drivers/usb/dwc3/dwc3-octeon.c
> index 0dc45dda134c..330bcb59cc95 100644
> --- a/drivers/usb/dwc3/dwc3-octeon.c
> +++ b/drivers/usb/dwc3/dwc3-octeon.c
> @@ -261,69 +261,15 @@ static int dwc3_octeon_get_divider(void)
>  }
>  
>  static int dwc3_octeon_setup(struct dwc3_octeon *octeon,
> +			     int ref_clk_sel, int ref_clk_fsel, int mpll_mul,
>  			     int power_gpio, int power_active_low)
>  {
> -	int i, div, mpll_mul, ref_clk_fsel, ref_clk_sel = 2;
> -	u32 clock_rate;
>  	u64 val;
> +	int div;
>  	struct device *dev = octeon->dev;
>  	void __iomem *uctl_ctl_reg = octeon->base + USBDRD_UCTL_CTL;
>  	void __iomem *uctl_host_cfg_reg = octeon->base + USBDRD_UCTL_HOST_CFG;
>  
> -	if (dev->of_node) {
> -		const char *ss_clock_type;
> -		const char *hs_clock_type;
> -
> -		i = of_property_read_u32(dev->of_node,
> -					 "refclk-frequency", &clock_rate);
> -		if (i) {
> -			dev_err(dev, "No UCTL \"refclk-frequency\"\n");
> -			return -EINVAL;
> -		}
> -		i = of_property_read_string(dev->of_node,
> -					    "refclk-type-ss", &ss_clock_type);
> -		if (i) {
> -			dev_err(dev, "No UCTL \"refclk-type-ss\"\n");
> -			return -EINVAL;
> -		}
> -		i = of_property_read_string(dev->of_node,
> -					    "refclk-type-hs", &hs_clock_type);
> -		if (i) {
> -			dev_err(dev, "No UCTL \"refclk-type-hs\"\n");
> -			return -EINVAL;
> -		}
> -		if (strcmp("dlmc_ref_clk0", ss_clock_type) == 0) {
> -			if (strcmp(hs_clock_type, "dlmc_ref_clk0") == 0)
> -				ref_clk_sel = 0;
> -			else if (strcmp(hs_clock_type, "pll_ref_clk") == 0)
> -				ref_clk_sel = 2;
> -			else
> -				dev_warn(dev, "Invalid HS clock type %s, using pll_ref_clk instead\n",
> -					 hs_clock_type);
> -		} else if (strcmp(ss_clock_type, "dlmc_ref_clk1") == 0) {
> -			if (strcmp(hs_clock_type, "dlmc_ref_clk1") == 0)
> -				ref_clk_sel = 1;
> -			else if (strcmp(hs_clock_type, "pll_ref_clk") == 0)
> -				ref_clk_sel = 3;
> -			else {
> -				dev_warn(dev, "Invalid HS clock type %s, using pll_ref_clk instead\n",
> -					 hs_clock_type);
> -				ref_clk_sel = 3;
> -			}
> -		} else
> -			dev_warn(dev, "Invalid SS clock type %s, using dlmc_ref_clk0 instead\n",
> -				 ss_clock_type);
> -
> -		if ((ref_clk_sel == 0 || ref_clk_sel == 1) &&
> -		    (clock_rate != 100000000))
> -			dev_warn(dev, "Invalid UCTL clock rate of %u, using 100000000 instead\n",
> -				 clock_rate);
> -
> -	} else {
> -		dev_err(dev, "No USB UCTL device node\n");
> -		return -EINVAL;
> -	}
> -
>  	/*
>  	 * Step 1: Wait for all voltages to be stable...that surely
>  	 *         happened before starting the kernel. SKIP
> @@ -367,24 +313,6 @@ static int dwc3_octeon_setup(struct dwc3_octeon *octeon,
>  	val &= ~USBDRD_UCTL_CTL_REF_CLK_SEL;
>  	val |= FIELD_PREP(USBDRD_UCTL_CTL_REF_CLK_SEL, ref_clk_sel);
>  
> -	ref_clk_fsel = 0x07;
> -	switch (clock_rate) {
> -	default:
> -		dev_warn(dev, "Invalid ref_clk %u, using 100000000 instead\n",
> -			 clock_rate);
> -		fallthrough;
> -	case 100000000:
> -		mpll_mul = 0x19;
> -		if (ref_clk_sel < 2)
> -			ref_clk_fsel = 0x27;
> -		break;
> -	case 50000000:
> -		mpll_mul = 0x32;
> -		break;
> -	case 125000000:
> -		mpll_mul = 0x28;
> -		break;
> -	}
>  	val &= ~USBDRD_UCTL_CTL_REF_CLK_FSEL;
>  	val |= FIELD_PREP(USBDRD_UCTL_CTL_REF_CLK_FSEL, ref_clk_fsel);
>  
> @@ -483,8 +411,64 @@ static int dwc3_octeon_probe(struct platform_device *pdev)
>  	struct device *dev = &pdev->dev;
>  	struct device_node *node = dev->of_node;
>  	struct dwc3_octeon *octeon;
> +	const char *hs_clock_type, *ss_clock_type;
> +	int ref_clk_sel, ref_clk_fsel, mpll_mul;
>  	int power_active_low, power_gpio;
>  	int err, len;
> +	u32 clock_rate;
> +
> +	if (of_property_read_u32(node, "refclk-frequency", &clock_rate)) {
> +		dev_err(dev, "No UCTL \"refclk-frequency\"\n");
> +		return -EINVAL;
> +	}
> +	if (of_property_read_string(node, "refclk-type-ss", &ss_clock_type)) {
> +		dev_err(dev, "No UCTL \"refclk-type-ss\"\n");
> +		return -EINVAL;
> +	}
> +	if (of_property_read_string(node, "refclk-type-hs", &hs_clock_type)) {
> +		dev_err(dev, "No UCTL \"refclk-type-hs\"\n");
> +		return -EINVAL;
> +	}
> +
> +	ref_clk_sel = 2;
> +	if (strcmp("dlmc_ref_clk0", ss_clock_type) == 0) {
> +		if (strcmp(hs_clock_type, "dlmc_ref_clk0") == 0)
> +			ref_clk_sel = 0;
> +		else if (strcmp(hs_clock_type, "pll_ref_clk"))
> +			dev_warn(dev, "Invalid HS clock type %s, using pll_ref_clk instead\n",
> +				 hs_clock_type);
> +	} else if (strcmp(ss_clock_type, "dlmc_ref_clk1") == 0) {
> +		if (strcmp(hs_clock_type, "dlmc_ref_clk1") == 0) {
> +			ref_clk_sel = 1;
> +		} else {
> +			ref_clk_sel = 3;
> +			if (strcmp(hs_clock_type, "pll_ref_clk"))
> +				dev_warn(dev, "Invalid HS clock type %s, using pll_ref_clk instead\n",
> +					 hs_clock_type);
> +		}
> +	} else {
> +		dev_warn(dev, "Invalid SS clock type %s, using dlmc_ref_clk0 instead\n",
> +			 ss_clock_type);
> +	}
> +
> +	ref_clk_fsel = 0x07;
> +	switch (clock_rate) {
> +	default:
> +		dev_warn(dev, "Invalid ref_clk %u, using 100000000 instead\n",
> +			 clock_rate);
> +		fallthrough;
> +	case 100000000:
> +		mpll_mul = 0x19;
> +		if (ref_clk_sel < 2)
> +			ref_clk_fsel = 0x27;
> +		break;
> +	case 50000000:
> +		mpll_mul = 0x32;
> +		break;
> +	case 125000000:
> +		mpll_mul = 0x28;
> +		break;
> +	}
>  
>  	power_gpio = DWC3_GPIO_POWER_NONE;
>  	power_active_low = 0;
> @@ -515,7 +499,8 @@ static int dwc3_octeon_probe(struct platform_device *pdev)
>  	if (IS_ERR(octeon->base))
>  		return PTR_ERR(octeon->base);
>  
> -	err = dwc3_octeon_setup(octeon, power_gpio, power_active_low);
> +	err = dwc3_octeon_setup(octeon, ref_clk_sel, ref_clk_fsel, mpll_mul,
> +				power_gpio, power_active_low);
>  	if (err)
>  		return err;
>  
> -- 
> 2.39.2
> 

Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>

Thanks,
Thinh