usb: phy: Add AM335x PHY driver

This driver is a redo of my earlier attempt. It uses parts of the
generic PHY driver and uses the new control driver for the register
the phy needs to power on/off the phy. It also enables easy access for
the wakeup register which is not yet implemented.
The difference between the omap attempt is:
- no static holding variable
- one global visible function which exports a struct with callbacks to
  access the "control" registers.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>

1 files changed, 136 insertions, 0 deletions

diff --git a/drivers/usb/phy/phy-am335x-control.c b/drivers/usb/phy/phy-am335x-control.c
new file mode 100644
index 000000000000..35494f1c33b6
--- /dev/null
+++ b/drivers/usb/phy/phy-am335x-control.c
@@ -0,0 +1,136 @@
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/io.h>
+
+struct phy_control {
+	void (*phy_power)(struct phy_control *phy_ctrl, u32 id, bool on);
+	void (*phy_wkup)(struct phy_control *phy_ctrl, u32 id, bool on);
+};
+
+struct am335x_control_usb {
+	struct device *dev;
+	void __iomem *phy_reg;
+	void __iomem *wkup;
+	spinlock_t lock;
+	struct phy_control phy_ctrl;
+};
+
+#define AM335X_USB0_CTRL		0x0
+#define AM335X_USB1_CTRL		0x8
+#define AM335x_USB_WKUP			0x0
+
+#define USBPHY_CM_PWRDN		(1 << 0)
+#define USBPHY_OTG_PWRDN	(1 << 1)
+#define USBPHY_OTGVDET_EN	(1 << 19)
+#define USBPHY_OTGSESSEND_EN	(1 << 20)
+
+static void am335x_phy_power(struct phy_control *phy_ctrl, u32 id, bool on)
+{
+	struct am335x_control_usb *usb_ctrl;
+	u32 val;
+	u32 reg;
+
+	usb_ctrl = container_of(phy_ctrl, struct am335x_control_usb, phy_ctrl);
+
+	switch (id) {
+	case 0:
+		reg = AM335X_USB0_CTRL;
+		break;
+	case 1:
+		reg = AM335X_USB1_CTRL;
+		break;
+	default:
+		__WARN();
+		 return;
+	}
+
+	val = readl(usb_ctrl->phy_reg + reg);
+	if (on) {
+		val &= ~(USBPHY_CM_PWRDN | USBPHY_OTG_PWRDN);
+		val |= USBPHY_OTGVDET_EN | USBPHY_OTGSESSEND_EN;
+	} else {
+		val |= USBPHY_CM_PWRDN | USBPHY_OTG_PWRDN;
+	}
+
+	writel(val, usb_ctrl->phy_reg + reg);
+}
+
+static const struct phy_control ctrl_am335x = {
+	.phy_power = am335x_phy_power,
+};
+
+static const struct of_device_id omap_control_usb_id_table[] = {
+	{ .compatible = "ti,am335x-usb-ctrl-module", .data = &ctrl_am335x },
+	{}
+};
+MODULE_DEVICE_TABLE(of, omap_control_usb_id_table);
+
+static struct platform_driver am335x_control_driver;
+static int match(struct device *dev, void *data)
+{
+	struct device_node *node = (struct device_node *)data;
+	return dev->of_node == node &&
+		dev->driver == &am335x_control_driver.driver;
+}
+
+struct phy_control *am335x_get_phy_control(struct device *dev)
+{
+	struct device_node *node;
+	struct am335x_control_usb *ctrl_usb;
+
+	node = of_parse_phandle(dev->of_node, "ti,ctrl_mod", 0);
+	if (!node)
+		return NULL;
+
+	dev = bus_find_device(&platform_bus_type, NULL, node, match);
+	ctrl_usb = dev_get_drvdata(dev);
+	if (!ctrl_usb)
+		return NULL;
+	return &ctrl_usb->phy_ctrl;
+}
+EXPORT_SYMBOL_GPL(am335x_get_phy_control);
+
+static int am335x_control_usb_probe(struct platform_device *pdev)
+{
+	struct resource	*res;
+	struct am335x_control_usb *ctrl_usb;
+	const struct of_device_id *of_id;
+	const struct phy_control *phy_ctrl;
+
+	of_id = of_match_node(omap_control_usb_id_table, pdev->dev.of_node);
+	if (!of_id)
+		return -EINVAL;
+
+	phy_ctrl = of_id->data;
+
+	ctrl_usb = devm_kzalloc(&pdev->dev, sizeof(*ctrl_usb), GFP_KERNEL);
+	if (!ctrl_usb) {
+		dev_err(&pdev->dev, "unable to alloc memory for control usb\n");
+		return -ENOMEM;
+	}
+
+	ctrl_usb->dev = &pdev->dev;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "phy_ctrl");
+	ctrl_usb->phy_reg = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(ctrl_usb->phy_reg))
+		return PTR_ERR(ctrl_usb->phy_reg);
+	spin_lock_init(&ctrl_usb->lock);
+	ctrl_usb->phy_ctrl = *phy_ctrl;
+
+	dev_set_drvdata(ctrl_usb->dev, ctrl_usb);
+	return 0;
+}
+
+static struct platform_driver am335x_control_driver = {
+	.probe		= am335x_control_usb_probe,
+	.driver		= {
+		.name	= "am335x-control-usb",
+		.owner	= THIS_MODULE,
+		.of_match_table = of_match_ptr(omap_control_usb_id_table),
+	},
+};
+
+module_platform_driver(am335x_control_driver);
+MODULE_LICENSE("GPL v2");