[PATCH 2/4] usb: ohci-at91: Enable OHCI functionality and register into DM

[Sergiu Moga <sergiu.moga@microchip.com>]

Register the OHCI driver into DM by properly initializing the required
clocks and pins required by the DT node of OHCI. In order for the VBUS
to stay enabled, a `child_pre_probe` method has been added to overcome
the DM core disabling it in `usb_scan_device`: when the generic
`device_probe` method is called, the pinctrl is processed once again,
undoing whatever changes have been made in our driver's probe method.

Signed-off-by: Sergiu Moga <sergiu.moga@microchip.com>
---
 drivers/usb/host/ohci-at91.c | 183 +++++++++++++++++++++++++++++++++++
 1 file changed, 183 insertions(+)

diff --git a/drivers/usb/host/ohci-at91.c b/drivers/usb/host/ohci-at91.c
index 9b955c1bd6..9ae55c6e5d 100644
--- a/drivers/usb/host/ohci-at91.c
+++ b/drivers/usb/host/ohci-at91.c
@@ -5,6 +5,9 @@
  */
 
 #include <common.h>
+
+#if !(CONFIG_IS_ENABLED(DM_USB))
+
 #include <asm/arch/clk.h>
 
 int usb_cpu_init(void)
@@ -62,3 +65,183 @@ int usb_cpu_init_fail(void)
 {
 	return usb_cpu_stop();
 }
+
+#elif CONFIG_IS_ENABLED(DM_GPIO)
+
+#include <clk.h>
+#include <dm.h>
+#include <asm/gpio.h>
+#include <usb.h>
+#include "ohci.h"
+
+#define AT91_MAX_USBH_PORTS        3
+
+#define at91_for_each_port(index)	\
+		for ((index) = 0; (index) < AT91_MAX_USBH_PORTS; (index)++)
+
+struct at91_usbh_data {
+	enum usb_init_type init_type;
+	struct gpio_desc vbus_pin[AT91_MAX_USBH_PORTS];
+	u8 ports;				/* number of ports on root hub */
+};
+
+struct ohci_at91_priv {
+	struct clk *iclk;
+	struct clk *fclk;
+	struct clk *hclk;
+	bool clocked;
+};
+
+static void at91_start_clock(struct ohci_at91_priv *ohci_at91)
+{
+	if (ohci_at91->clocked)
+		return;
+
+	clk_set_rate(ohci_at91->fclk, 48000000);
+	clk_prepare_enable(ohci_at91->hclk);
+	clk_prepare_enable(ohci_at91->iclk);
+	clk_prepare_enable(ohci_at91->fclk);
+	ohci_at91->clocked = true;
+}
+
+static void at91_stop_clock(struct ohci_at91_priv *ohci_at91)
+{
+	if (!ohci_at91->clocked)
+		return;
+
+	clk_disable_unprepare(ohci_at91->fclk);
+	clk_disable_unprepare(ohci_at91->iclk);
+	clk_disable_unprepare(ohci_at91->hclk);
+	ohci_at91->clocked = false;
+}
+
+static void ohci_at91_set_power(struct at91_usbh_data *pdata, int port,
+				bool enable)
+{
+	if (!dm_gpio_is_valid(&pdata->vbus_pin[port]))
+		return;
+
+	if (enable)
+		dm_gpio_set_dir_flags(&pdata->vbus_pin[port],
+				      GPIOD_IS_OUT | GPIOD_IS_OUT_ACTIVE);
+	else
+		dm_gpio_set_dir_flags(&pdata->vbus_pin[port], 0);
+}
+
+static void at91_start_hc(struct udevice *dev)
+{
+	struct ohci_at91_priv *ohci_at91 = dev_get_priv(dev);
+
+	at91_start_clock(ohci_at91);
+}
+
+static void at91_stop_hc(struct udevice *dev)
+{
+	struct ohci_at91_priv *ohci_at91 = dev_get_priv(dev);
+
+	at91_stop_clock(ohci_at91);
+}
+
+static int ohci_atmel_deregister(struct udevice *dev)
+{
+	struct at91_usbh_data *pdata = dev_get_plat(dev);
+	int i;
+
+	at91_stop_hc(dev);
+
+	at91_for_each_port(i) {
+		if (i >= pdata->ports)
+			break;
+
+		ohci_at91_set_power(pdata, i, false);
+	}
+
+	return ohci_deregister(dev);
+}
+
+static int ohci_atmel_child_pre_probe(struct udevice *dev)
+{
+	struct udevice *ohci_controller = dev_get_parent(dev);
+	struct at91_usbh_data *pdata = dev_get_plat(ohci_controller);
+	int i;
+
+	at91_for_each_port(i) {
+		if (i >= pdata->ports)
+			break;
+
+		ohci_at91_set_power(pdata, i, true);
+	}
+
+	return 0;
+}
+
+static int ohci_atmel_probe(struct udevice *dev)
+{
+	struct at91_usbh_data *pdata = dev_get_plat(dev);
+	struct ohci_at91_priv *ohci_at91 = dev_get_priv(dev);
+	int		      i;
+	int		      ret;
+	u32		      ports;
+	struct ohci_regs      *regs = (struct ohci_regs *)dev_read_addr(dev);
+
+	if (!dev_read_u32(dev, "num-ports", &ports))
+		pdata->ports = ports;
+
+	at91_for_each_port(i) {
+		if (i >= pdata->ports)
+			break;
+
+		gpio_request_by_name(dev, "atmel,vbus-gpio", i,
+				     &pdata->vbus_pin[i], GPIOD_IS_OUT |
+				     GPIOD_IS_OUT_ACTIVE);
+	}
+
+	ohci_at91->iclk = devm_clk_get(dev, "ohci_clk");
+	if (IS_ERR(ohci_at91->iclk)) {
+		ret = PTR_ERR(ohci_at91->iclk);
+		goto fail;
+	}
+
+	ohci_at91->fclk = devm_clk_get(dev, "uhpck");
+	if (IS_ERR(ohci_at91->fclk)) {
+		ret = PTR_ERR(ohci_at91->fclk);
+		goto fail;
+	}
+
+	ohci_at91->hclk = devm_clk_get(dev, "hclk");
+	if (IS_ERR(ohci_at91->hclk)) {
+		ret = PTR_ERR(ohci_at91->hclk);
+		goto fail;
+	}
+
+	at91_start_hc(dev);
+
+	return ohci_register(dev, regs);
+
+fail:
+	at91_for_each_port(i)
+		if (dm_gpio_is_valid(&pdata->vbus_pin[i]))
+			gpio_free(pdata->vbus_pin[i].offset);
+
+	return ret;
+}
+
+static const struct udevice_id ohci_usb_ids[] = {
+	{ .compatible = "atmel,at91rm9200-ohci", },
+	{ }
+};
+
+U_BOOT_DRIVER(ohci_atmel) = {
+	.name		 = "ohci_atmel",
+	.id		 = UCLASS_USB,
+	.of_match	 = ohci_usb_ids,
+	.probe		 = ohci_atmel_probe,
+	.remove		 = ohci_atmel_deregister,
+	.child_pre_probe = ohci_atmel_child_pre_probe,
+	.ops		 = &ohci_usb_ops,
+	.plat_auto	 = sizeof(struct at91_usbh_data),
+	.priv_auto	 = sizeof(struct ohci_at91_priv),
+	.flags		 = DM_FLAG_ALLOC_PRIV_DMA,
+};
+
+#endif /* CONFIG_IS_ENABLED(DM_USB) && CONFIG_IS_ENABLED(DM_GPIO) */
-- 
2.34.1