Re: [PATCH] phy: Add a driver for dm816x USB PHY
From: Kishon Vijay Abraham I
Date: Wed Mar 11 2015 - 05:58:23 EST
Hi Tony,
On Tuesday 10 March 2015 02:21 AM, Tony Lindgren wrote:
Add a minimal driver for dm816x USB. Otherwise we can just use
the existing musb_am335x and musb_dsps on dm816x.
If we can use an existing driver, I'd prefer that.
Cc: Brian Hutchinson <b.hutchman@xxxxxxxxx>
Cc: Felipe Balbi <balbi@xxxxxx>
Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
--- /dev/null
+++ b/Documentation/devicetree/bindings/phy/dm816x-phy.txt
@@ -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>;
+};
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -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 dm81xx USB to work."
+
config PHY_EXYNOS_MIPI_VIDEO
tristate "S5P/EXYNOS SoC series MIPI CSI-2/DSI PHY driver"
depends on HAS_IOMEM
--- a/drivers/phy/Makefile
+++ b/drivers/phy/Makefile
@@ -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
--- /dev/null
+++ b/drivers/phy/phy-dm816x-usb.c
@@ -0,0 +1,295 @@
+/*
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; 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.
+ */
+#define DM816X_USB_CTRL_PHYCLKSRC BIT(8) /* 1 = PLL ref clock */
+#define DM816X_USB_CTRL_PHYSLEEP1 BIT(1)
+#define DM816X_USB_CTRL_PHYSLEEP0 BIT(0)
+
+#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_power_off(struct phy *x)
+{
+ struct dm816x_usb_phy *phy = phy_get_drvdata(x);
+
+ pm_runtime_put(phy->dev);
phy core takes care of invoking pm_runtime_put on power_off.
So this function shouldn't be needed at all.
+
+ return 0;
+}
+
+static int dm816x_usb_phy_power_on(struct phy *x)
+{
+ struct dm816x_usb_phy *phy = phy_get_drvdata(x);
+
+ return pm_runtime_get_sync(phy->dev);
similarly on power_on, phy_core invokes pm_runtime_get_sync.
+}
+
+static int dm816x_usb_phy_init(struct phy *x)
+{
+ struct dm816x_usb_phy *phy = phy_get_drvdata(x);
+ unsigned int val;
+ int error;
+
+ error = pm_runtime_get_sync(phy->dev);
+ if (error)
+ return error;
not required.
+
+ 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);
+
+ /*
+ * 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);
+
+ pm_runtime_put(phy->dev);
same here.
+
+ return 0;
+}
+
+static struct phy_ops ops = {
+ .init = dm816x_usb_phy_init,
+ .power_on = dm816x_usb_phy_power_on,
+ .power_off = dm816x_usb_phy_power_off,
+ .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;
+
+ 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);
+
+ generic_phy = devm_phy_create(phy->dev, NULL, &ops);
+ if (IS_ERR(generic_phy))
+ return PTR_ERR(generic_phy);
Just invoke pm_runtime_enable before phy_create and phy core will take care of
invoking all pm_runtime functions at appropriate time.
Cheers
Kishon
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