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>

5 files changed, 270 insertions, 0 deletions

diff --git a/drivers/usb/phy/Kconfig b/drivers/usb/phy/Kconfig
index f5ea339ec155..f41c3e12c6a7 100644
--- a/drivers/usb/phy/Kconfig
+++ b/drivers/usb/phy/Kconfig
@@ -86,6 +86,18 @@ config OMAP_USB3
           This driver interacts with the "OMAP Control USB Driver" to power
           on/off the PHY.
 
+config AM335X_CONTROL_USB
+        tristate
+
+config AM335X_PHY_USB
+        tristate "AM335x USB PHY Driver"
+        select USB_PHY
+        select AM335X_CONTROL_USB
+        select NOP_USB_XCEIV
+        help
+          This driver provides PHY support for that phy which part for the
+          AM335x SoC.
+
 config SAMSUNG_USBPHY
         tristate
         help
diff --git a/drivers/usb/phy/Makefile b/drivers/usb/phy/Makefile
index 24c5816409fd..dae321de3b2e 100644
--- a/drivers/usb/phy/Makefile
+++ b/drivers/usb/phy/Makefile
@@ -16,6 +16,8 @@ obj-$(CONFIG_ISP1301_OMAP)		+= phy-isp1301-omap.o
 obj-$(CONFIG_MV_U3D_PHY)                += phy-mv-u3d-usb.o
 obj-$(CONFIG_NOP_USB_XCEIV)             += phy-generic.o
 obj-$(CONFIG_OMAP_CONTROL_USB)          += phy-omap-control.o
+obj-$(CONFIG_AM335X_CONTROL_USB)        += phy-am335x-control.o
+obj-$(CONFIG_AM335X_PHY_USB)            += phy-am335x.o
 obj-$(CONFIG_OMAP_USB2)                 += phy-omap-usb2.o
 obj-$(CONFIG_OMAP_USB3)                 += phy-omap-usb3.o
 obj-$(CONFIG_SAMSUNG_USBPHY)            += phy-samsung-usb.o
diff --git a/drivers/usb/phy/am35x-phy-control.h b/drivers/usb/phy/am35x-phy-control.h
new file mode 100644
index 000000000000..b96594d1962c
--- /dev/null
+++ b/drivers/usb/phy/am35x-phy-control.h
@@ -0,0 +1,21 @@
+#ifndef _AM335x_PHY_CONTROL_H_
+#define _AM335x_PHY_CONTROL_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);
+};
+
+static inline void phy_ctrl_power(struct phy_control *phy_ctrl, u32 id, bool on)
+{
+        phy_ctrl->phy_power(phy_ctrl, id, on);
+}
+
+static inline void phy_ctrl_wkup(struct phy_control *phy_ctrl, u32 id, bool on)
+{
+        phy_ctrl->phy_wkup(phy_ctrl, id, on);
+}
+
+struct phy_control *am335x_get_phy_control(struct device *dev);
+
+#endif
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");
diff --git a/drivers/usb/phy/phy-am335x.c b/drivers/usb/phy/phy-am335x.c
new file mode 100644
index 000000000000..c4d614d1f173
--- /dev/null
+++ b/drivers/usb/phy/phy-am335x.c
@@ -0,0 +1,99 @@
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/dma-mapping.h>
+#include <linux/usb/otg.h>
+#include <linux/usb/usb_phy_gen_xceiv.h>
+#include <linux/slab.h>
+#include <linux/clk.h>
+#include <linux/regulator/consumer.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+
+#include "am35x-phy-control.h"
+#include "phy-generic.h"
+
+struct am335x_phy {
+        struct usb_phy_gen_xceiv usb_phy_gen;
+        struct phy_control *phy_ctrl;
+        int id;
+};
+
+static int am335x_init(struct usb_phy *phy)
+{
+        struct am335x_phy *am_phy = dev_get_drvdata(phy->dev);
+
+        phy_ctrl_power(am_phy->phy_ctrl, am_phy->id, true);
+        return 0;
+}
+
+static void am335x_shutdown(struct usb_phy *phy)
+{
+        struct am335x_phy *am_phy = dev_get_drvdata(phy->dev);
+
+        phy_ctrl_power(am_phy->phy_ctrl, am_phy->id, false);
+}
+
+static int am335x_phy_probe(struct platform_device *pdev)
+{
+        struct am335x_phy *am_phy;
+        struct device *dev = &pdev->dev;
+        int ret;
+
+        am_phy = devm_kzalloc(dev, sizeof(*am_phy), GFP_KERNEL);
+        if (!am_phy)
+                return -ENOMEM;
+
+        am_phy->phy_ctrl = am335x_get_phy_control(dev);
+        if (!am_phy->phy_ctrl)
+                return -EPROBE_DEFER;
+        am_phy->id = of_alias_get_id(pdev->dev.of_node, "phy");
+        if (am_phy->id < 0) {
+                dev_err(&pdev->dev, "Missing PHY id: %d\n", am_phy->id);
+                return am_phy->id;
+        }
+
+        ret = usb_phy_gen_create_phy(dev, &am_phy->usb_phy_gen,
+                        USB_PHY_TYPE_USB2, 0, false, false);
+        if (ret)
+                return ret;
+
+        ret = usb_add_phy_dev(&am_phy->usb_phy_gen.phy);
+        if (ret)
+                goto err_add;
+        am_phy->usb_phy_gen.phy.init = am335x_init;
+        am_phy->usb_phy_gen.phy.shutdown = am335x_shutdown;
+
+        platform_set_drvdata(pdev, am_phy);
+        return 0;
+
+err_add:
+        usb_phy_gen_cleanup_phy(&am_phy->usb_phy_gen);
+        return ret;
+}
+
+static int am335x_phy_remove(struct platform_device *pdev)
+{
+        struct am335x_phy *am_phy = platform_get_drvdata(pdev);
+
+        usb_remove_phy(&am_phy->usb_phy_gen.phy);
+        return 0;
+}
+
+static const struct of_device_id am335x_phy_ids[] = {
+        { .compatible = "ti,am335x-usb-phy" },
+        { }
+};
+MODULE_DEVICE_TABLE(of, am335x_phy_ids);
+
+static struct platform_driver am335x_phy_driver = {
+        .probe          = am335x_phy_probe,
+        .remove         = am335x_phy_remove,
+        .driver         = {
+                .name   = "am335x-phy-driver",
+                .owner  = THIS_MODULE,
+                .of_match_table = of_match_ptr(am335x_phy_ids),
+        },
+};
+
+module_platform_driver(am335x_phy_driver);
+MODULE_LICENSE("GPL v2");