Re: [PATCH v6 1/5] usb: cdns3-ti: move reg writes to separate function

Roger Quadros
2024-12-12T12:12:08Z

On 10/12/2024 19:13, Théo Lebrun wrote:
> The device probe function mixes management code and hardware
> initialisation code. Extract the latter into an explicitly named
> cdns_ti_reset_and_init_hw() function to clarify intent. It also will
> allow easier transition to using runtime PM for triggering HW init.
>
> Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
> ---
> drivers/usb/cdns3/cdns3-ti.c | 84 ++++++++++++++++++++++++--------------------
> 1 file changed, 46 insertions(+), 38 deletions(-)
>
> diff --git a/drivers/usb/cdns3/cdns3-ti.c b/drivers/usb/cdns3/cdns3-ti.c
> index 040bb91e9c017d8298a7e251fd0e192a336e8a52..d704eb39820ad08a8774be7f00aa473c3ff267c0 100644
> --- a/drivers/usb/cdns3/cdns3-ti.c
> +++ b/drivers/usb/cdns3/cdns3-ti.c
> @@ -58,6 +58,7 @@ struct cdns_ti {
> unsigned vbus_divider:1;
> struct clk *usb2_refclk;
> struct clk *lpm_clk;
> + int usb2_refclk_rate_code;
> };
>
> static const int cdns_ti_rate_table[] = { /* in KHZ */
> @@ -98,15 +99,52 @@ static const struct of_dev_auxdata cdns_ti_auxdata[] = {
> {},
> };
>
> +static void cdns_ti_reset_and_init_hw(struct cdns_ti *data)
> +{
> + u32 reg;
> +
> + /* assert RESET */
> + reg = cdns_ti_readl(data, USBSS_W1);
> + reg &= ~USBSS_W1_PWRUP_RST;
> + cdns_ti_writel(data, USBSS_W1, reg);
> +
> + /* set static config */
> + reg = cdns_ti_readl(data, USBSS_STATIC_CONFIG);
> + reg &= ~USBSS1_STATIC_PLL_REF_SEL_MASK;
> + reg |= data->usb2_refclk_rate_code << USBSS1_STATIC_PLL_REF_SEL_SHIFT;
> +
> + reg &= ~USBSS1_STATIC_VBUS_SEL_MASK;
> +
new line not required?

> + if (data->vbus_divider)
> + reg |= 1 << USBSS1_STATIC_VBUS_SEL_SHIFT;
> +
> + cdns_ti_writel(data, USBSS_STATIC_CONFIG, reg);
> + reg = cdns_ti_readl(data, USBSS_STATIC_CONFIG);
> +
> + /* set USB2_ONLY mode if requested */
> + reg = cdns_ti_readl(data, USBSS_W1);
> +
here too?

> + if (data->usb2_only)
> + reg |= USBSS_W1_USB2_ONLY;
> +
> + /* set default modestrap */
> + reg |= USBSS_W1_MODESTRAP_SEL;
> + reg &= ~USBSS_W1_MODESTRAP_MASK;
> + reg |= USBSS_MODESTRAP_MODE_NONE << USBSS_W1_MODESTRAP_SHIFT;
> + cdns_ti_writel(data, USBSS_W1, reg);
> +
> + /* de-assert RESET */
> + reg |= USBSS_W1_PWRUP_RST;
> + cdns_ti_writel(data, USBSS_W1, reg);
> +}
> +
> static int cdns_ti_probe(struct platform_device *pdev)
> {
> struct device *dev = &pdev->dev;
> struct device_node *node = pdev->dev.of_node;
> struct cdns_ti *data;
> - int error;
> - u32 reg;
> - int rate_code, i;
> unsigned long rate;
> + int error, i;
>
> data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
> if (!data)
> @@ -146,7 +184,11 @@ static int cdns_ti_probe(struct platform_device *pdev)
> return -EINVAL;
> }
>
> - rate_code = i;
> + data->usb2_refclk_rate_code = i;
> + data->vbus_divider = device_property_read_bool(dev, "ti,vbus-divider");
> + data->usb2_only = device_property_read_bool(dev, "ti,usb2-only");
> +
> + cdns_ti_reset_and_init_hw(data);
>
> pm_runtime_enable(dev);
> error = pm_runtime_get_sync(dev);
> @@ -155,40 +197,6 @@ static int cdns_ti_probe(struct platform_device *pdev)
> goto err;
> }
>
> - /* assert RESET */
> - reg = cdns_ti_readl(data, USBSS_W1);
> - reg &= ~USBSS_W1_PWRUP_RST;
> - cdns_ti_writel(data, USBSS_W1, reg);
> -
> - /* set static config */
> - reg = cdns_ti_readl(data, USBSS_STATIC_CONFIG);
> - reg &= ~USBSS1_STATIC_PLL_REF_SEL_MASK;
> - reg |= rate_code << USBSS1_STATIC_PLL_REF_SEL_SHIFT;
> -
> - reg &= ~USBSS1_STATIC_VBUS_SEL_MASK;
> - data->vbus_divider = device_property_read_bool(dev, "ti,vbus-divider");
> - if (data->vbus_divider)
> - reg |= 1 << USBSS1_STATIC_VBUS_SEL_SHIFT;
> -
> - cdns_ti_writel(data, USBSS_STATIC_CONFIG, reg);
> - reg = cdns_ti_readl(data, USBSS_STATIC_CONFIG);
> -
> - /* set USB2_ONLY mode if requested */
> - reg = cdns_ti_readl(data, USBSS_W1);
> - data->usb2_only = device_property_read_bool(dev, "ti,usb2-only");
> - if (data->usb2_only)
> - reg |= USBSS_W1_USB2_ONLY;
> -
> - /* set default modestrap */
> - reg |= USBSS_W1_MODESTRAP_SEL;
> - reg &= ~USBSS_W1_MODESTRAP_MASK;
> - reg |= USBSS_MODESTRAP_MODE_NONE << USBSS_W1_MODESTRAP_SHIFT;
> - cdns_ti_writel(data, USBSS_W1, reg);
> -
> - /* de-assert RESET */
> - reg |= USBSS_W1_PWRUP_RST;
> - cdns_ti_writel(data, USBSS_W1, reg);
> -
> error = of_platform_populate(node, NULL, cdns_ti_auxdata, dev);
> if (error) {
> dev_err(dev, "failed to create children: %d\n", error);
>

Reviewed-by: Roger Quadros <rogerq@kernel.org>

--
cheers,
-roger