phy: Add a driver for dm816x USB PHY
authorTony Lindgren <tony@atomide.com>
Fri, 20 Mar 2015 00:08:07 +0000 (17:08 -0700)
committerKishon Vijay Abraham I <kishon@ti.com>
Fri, 3 Apr 2015 12:46:19 +0000 (18:16 +0530)
Add a minimal driver for dm816x USB. This makes USB work on dm816x
without any other changes needed as it can use the existing musb_dsps
glue layer for the USB controller.

Note that this phy is different from dm814x and am335x.

Cc: Bin Liu <binmlist@gmail.com>
Cc: Brian Hutchinson <b.hutchman@gmail.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Matthijs van Duin <matthijsvanduin@gmail.com>
Cc: Paul Bolle <pebolle@tiscali.nl>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Documentation/devicetree/bindings/phy/dm816x-phy.txt [new file with mode: 0644]
drivers/phy/Kconfig
drivers/phy/Makefile
drivers/phy/phy-dm816x-usb.c [new file with mode: 0644]

diff --git a/Documentation/devicetree/bindings/phy/dm816x-phy.txt b/Documentation/devicetree/bindings/phy/dm816x-phy.txt
new file mode 100644 (file)
index 0000000..2fe3d11
--- /dev/null
@@ -0,0 +1,24 @@
+Device tree binding documentation for am816x USB PHY
+=========================
+
+Required properties:
+- compatible : should be "ti,dm816x-usb-phy"
+- reg : offset and length of the PHY register set.
+- reg-names : name for the phy registers
+- clocks : phandle to the clock
+- clock-names : name of the clock
+- syscon: phandle for the syscon node to access misc registers
+- #phy-cells : from the generic PHY bindings, must be 1
+- syscon: phandle for the syscon node to access misc registers
+
+Example:
+
+usb_phy0: usb-phy@20 {
+       compatible = "ti,dm8168-usb-phy";
+       reg = <0x20 0x8>;
+       reg-names = "phy";
+       clocks = <&main_fapll 6>;
+       clock-names = "refclk";
+       #phy-cells = <0>;
+       syscon = <&scm_conf>;
+};
index 2962de205ba7247bd06eeb5d89f752b30d39e9dc..885c39c28a8bcecf3a32f247a1aa4a857272dc34 100644 (file)
@@ -35,6 +35,13 @@ config ARMADA375_USBCLUSTER_PHY
        depends on OF
        select GENERIC_PHY
 
+config PHY_DM816X_USB
+       tristate "TI dm816x USB PHY driver"
+       depends on ARCH_OMAP2PLUS
+       select GENERIC_PHY
+       help
+         Enable this for dm816x USB to work.
+
 config PHY_EXYNOS_MIPI_VIDEO
        tristate "S5P/EXYNOS SoC series MIPI CSI-2/DSI PHY driver"
        depends on HAS_IOMEM
index f080e1bb2a74dc528757d01fbbaf917a8a962445..dab6665ad9c169c5b9096d1cf01bebfcff68e90c 100644 (file)
@@ -5,6 +5,7 @@
 obj-$(CONFIG_GENERIC_PHY)              += phy-core.o
 obj-$(CONFIG_PHY_BERLIN_USB)           += phy-berlin-usb.o
 obj-$(CONFIG_PHY_BERLIN_SATA)          += phy-berlin-sata.o
+obj-$(CONFIG_PHY_DM816X_USB)           += phy-dm816x-usb.o
 obj-$(CONFIG_ARMADA375_USBCLUSTER_PHY) += phy-armada375-usb2.o
 obj-$(CONFIG_BCM_KONA_USB2_PHY)                += phy-bcm-kona-usb2.o
 obj-$(CONFIG_PHY_EXYNOS_DP_VIDEO)      += phy-exynos-dp-video.o
diff --git a/drivers/phy/phy-dm816x-usb.c b/drivers/phy/phy-dm816x-usb.c
new file mode 100644 (file)
index 0000000..7b42555
--- /dev/null
@@ -0,0 +1,290 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/io.h>
+#include <linux/usb/phy_companion.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/pm_runtime.h>
+#include <linux/delay.h>
+#include <linux/phy/phy.h>
+#include <linux/of_platform.h>
+
+#include <linux/mfd/syscon.h>
+
+/*
+ * TRM has two sets of USB_CTRL registers.. The correct register bits
+ * are in TRM section 24.9.8.2 USB_CTRL Register. The TRM documents the
+ * phy as being SR70LX Synopsys USB 2.0 OTG nanoPHY. It also seems at
+ * least dm816x rev c ignores writes to USB_CTRL register, but the TI
+ * kernel is writing to those so it's possible that later revisions
+ * have worknig USB_CTRL register.
+ *
+ * Also note that At least USB_CTRL register seems to be dm816x specific
+ * according to the TRM. It's possible that USBPHY_CTRL is more generic,
+ * but that would have to be checked against the SR70LX documentation
+ * which does not seem to be publicly available.
+ *
+ * Finally, the phy on dm814x and am335x is different from dm816x.
+ */
+#define DM816X_USB_CTRL_PHYCLKSRC      BIT(8)  /* 1 = PLL ref clock */
+#define DM816X_USB_CTRL_PHYSLEEP1      BIT(1)  /* Enable the first phy */
+#define DM816X_USB_CTRL_PHYSLEEP0      BIT(0)  /* Enable the second phy */
+
+#define DM816X_USBPHY_CTRL_TXRISETUNE  1
+#define DM816X_USBPHY_CTRL_TXVREFTUNE  0xc
+#define DM816X_USBPHY_CTRL_TXPREEMTUNE 0x2
+
+struct dm816x_usb_phy {
+       struct regmap *syscon;
+       struct device *dev;
+       unsigned int instance;
+       struct clk *refclk;
+       struct usb_phy phy;
+       unsigned int usb_ctrl;          /* Shared between phy0 and phy1 */
+       unsigned int usbphy_ctrl;
+};
+
+static int dm816x_usb_phy_set_host(struct usb_otg *otg, struct usb_bus *host)
+{
+       otg->host = host;
+       if (!host)
+               otg->state = OTG_STATE_UNDEFINED;
+
+       return 0;
+}
+
+static int dm816x_usb_phy_set_peripheral(struct usb_otg *otg,
+                                        struct usb_gadget *gadget)
+{
+       otg->gadget = gadget;
+       if (!gadget)
+               otg->state = OTG_STATE_UNDEFINED;
+
+       return 0;
+}
+
+static int dm816x_usb_phy_init(struct phy *x)
+{
+       struct dm816x_usb_phy *phy = phy_get_drvdata(x);
+       unsigned int val;
+       int error;
+
+       if (clk_get_rate(phy->refclk) != 24000000)
+               dev_warn(phy->dev, "nonstandard phy refclk\n");
+
+       /* Set PLL ref clock and put phys to sleep */
+       error = regmap_update_bits(phy->syscon, phy->usb_ctrl,
+                                  DM816X_USB_CTRL_PHYCLKSRC |
+                                  DM816X_USB_CTRL_PHYSLEEP1 |
+                                  DM816X_USB_CTRL_PHYSLEEP0,
+                                  0);
+       regmap_read(phy->syscon, phy->usb_ctrl, &val);
+       if ((val & 3) != 0)
+               dev_info(phy->dev,
+                        "Working dm816x USB_CTRL! (0x%08x)\n",
+                        val);
+
+       /*
+        * TI kernel sets these values for "symmetrical eye diagram and
+        * better signal quality" so let's assume somebody checked the
+        * values with a scope and set them here too.
+        */
+       regmap_read(phy->syscon, phy->usbphy_ctrl, &val);
+       val |= DM816X_USBPHY_CTRL_TXRISETUNE |
+               DM816X_USBPHY_CTRL_TXVREFTUNE |
+               DM816X_USBPHY_CTRL_TXPREEMTUNE;
+       regmap_write(phy->syscon, phy->usbphy_ctrl, val);
+
+       return 0;
+}
+
+static struct phy_ops ops = {
+       .init           = dm816x_usb_phy_init,
+       .owner          = THIS_MODULE,
+};
+
+static int dm816x_usb_phy_runtime_suspend(struct device *dev)
+{
+       struct dm816x_usb_phy *phy = dev_get_drvdata(dev);
+       unsigned int mask, val;
+       int error = 0;
+
+       mask = BIT(phy->instance);
+       val = ~BIT(phy->instance);
+       error = regmap_update_bits(phy->syscon, phy->usb_ctrl,
+                                  mask, val);
+       if (error)
+               dev_err(phy->dev, "phy%i failed to power off\n",
+                       phy->instance);
+       clk_disable(phy->refclk);
+
+       return 0;
+}
+
+static int dm816x_usb_phy_runtime_resume(struct device *dev)
+{
+       struct dm816x_usb_phy *phy = dev_get_drvdata(dev);
+       unsigned int mask, val;
+       int error;
+
+       error = clk_enable(phy->refclk);
+       if (error)
+               return error;
+
+       /*
+        * Note that at least dm816x rev c does not seem to do
+        * anything with the USB_CTRL register. But let's follow
+        * what the TI tree is doing in case later revisions use
+        * USB_CTRL.
+        */
+       mask = BIT(phy->instance);
+       val = BIT(phy->instance);
+       error = regmap_update_bits(phy->syscon, phy->usb_ctrl,
+                                  mask, val);
+       if (error) {
+               dev_err(phy->dev, "phy%i failed to power on\n",
+                       phy->instance);
+               clk_disable(phy->refclk);
+               return error;
+       }
+
+       return 0;
+}
+
+static UNIVERSAL_DEV_PM_OPS(dm816x_usb_phy_pm_ops,
+                           dm816x_usb_phy_runtime_suspend,
+                           dm816x_usb_phy_runtime_resume,
+                           NULL);
+
+#ifdef CONFIG_OF
+static const struct of_device_id dm816x_usb_phy_id_table[] = {
+       {
+               .compatible = "ti,dm8168-usb-phy",
+       },
+       {},
+};
+MODULE_DEVICE_TABLE(of, dm816x_usb_phy_id_table);
+#endif
+
+static int dm816x_usb_phy_probe(struct platform_device *pdev)
+{
+       struct dm816x_usb_phy *phy;
+       struct resource *res;
+       struct phy *generic_phy;
+       struct phy_provider *phy_provider;
+       struct usb_otg *otg;
+       const struct of_device_id *of_id;
+       const struct usb_phy_data *phy_data;
+       int error;
+
+       of_id = of_match_device(of_match_ptr(dm816x_usb_phy_id_table),
+                               &pdev->dev);
+       if (!of_id)
+               return -EINVAL;
+
+       phy = devm_kzalloc(&pdev->dev, sizeof(*phy), GFP_KERNEL);
+       if (!phy)
+               return -ENOMEM;
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       if (!res)
+               return -ENOENT;
+
+       phy->syscon = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
+                                                     "syscon");
+       if (IS_ERR(phy->syscon))
+               return PTR_ERR(phy->syscon);
+
+       /*
+        * According to sprs614e.pdf, the first usb_ctrl is shared and
+        * the second instance for usb_ctrl is reserved.. Also the
+        * register bits are different from earlier TRMs.
+        */
+       phy->usb_ctrl = 0x20;
+       phy->usbphy_ctrl = (res->start & 0xff) + 4;
+       if (phy->usbphy_ctrl == 0x2c)
+               phy->instance = 1;
+
+       phy_data = of_id->data;
+
+       otg = devm_kzalloc(&pdev->dev, sizeof(*otg), GFP_KERNEL);
+       if (!otg)
+               return -ENOMEM;
+
+       phy->dev = &pdev->dev;
+       phy->phy.dev = phy->dev;
+       phy->phy.label = "dm8168_usb_phy";
+       phy->phy.otg = otg;
+       phy->phy.type = USB_PHY_TYPE_USB2;
+       otg->set_host = dm816x_usb_phy_set_host;
+       otg->set_peripheral = dm816x_usb_phy_set_peripheral;
+       otg->usb_phy = &phy->phy;
+
+       platform_set_drvdata(pdev, phy);
+
+       phy->refclk = devm_clk_get(phy->dev, "refclk");
+       if (IS_ERR(phy->refclk))
+               return PTR_ERR(phy->refclk);
+       error = clk_prepare(phy->refclk);
+       if (error)
+               return error;
+
+       pm_runtime_enable(phy->dev);
+       generic_phy = devm_phy_create(phy->dev, NULL, &ops);
+       if (IS_ERR(generic_phy))
+               return PTR_ERR(generic_phy);
+
+       phy_set_drvdata(generic_phy, phy);
+
+       phy_provider = devm_of_phy_provider_register(phy->dev,
+                                                    of_phy_simple_xlate);
+       if (IS_ERR(phy_provider))
+               return PTR_ERR(phy_provider);
+
+       usb_add_phy_dev(&phy->phy);
+
+       return 0;
+}
+
+static int dm816x_usb_phy_remove(struct platform_device *pdev)
+{
+       struct dm816x_usb_phy *phy = platform_get_drvdata(pdev);
+
+       usb_remove_phy(&phy->phy);
+       pm_runtime_disable(phy->dev);
+       clk_unprepare(phy->refclk);
+
+       return 0;
+}
+
+static struct platform_driver dm816x_usb_phy_driver = {
+       .probe          = dm816x_usb_phy_probe,
+       .remove         = dm816x_usb_phy_remove,
+       .driver         = {
+               .name   = "dm816x-usb-phy",
+               .pm     = &dm816x_usb_phy_pm_ops,
+               .of_match_table = of_match_ptr(dm816x_usb_phy_id_table),
+       },
+};
+
+module_platform_driver(dm816x_usb_phy_driver);
+
+MODULE_ALIAS("platform:dm816x_usb");
+MODULE_AUTHOR("Tony Lindgren <tony@atomide.com>");
+MODULE_DESCRIPTION("dm816x usb phy driver");
+MODULE_LICENSE("GPL v2");