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

Théo Lebrun
2024-12-10T17:13:44Z

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;
+
+ 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);
+
+ 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);

--
2.47.1