Re: [PATCH v4] extcon: Palmas Extcon Driver
From: Kishon Vijay Abraham I
Date: Tue May 07 2013 - 02:26:20 EST
Hi,
On Tuesday 07 May 2013 11:40 AM, Chanwoo Choi wrote:
Hi Kishon,
I add some opinion about this patch.
On 05/06/2013 10:17 PM, Kishon Vijay Abraham I wrote:
From: Graeme Gregory <gg@xxxxxxxxxxxxxxx>
This is the driver for the USB comparator built into the palmas chip. It
handles the various USB OTG events that can be generated by cable
insertion/removal.
Signed-off-by: Graeme Gregory <gg@xxxxxxxxxxxxxxx>
Signed-off-by: Moiz Sonasath <m-sonasath@xxxxxx>
Signed-off-by: Ruchika Kharwar <ruchika@xxxxxx>
Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
[kishon@xxxxxx: adapted palmas usb driver to use the extcon framework]
Signed-off-by: Sebastien Guiriec <s-guiriec@xxxxxx>
---
Changes from v3:
* adapted the driver to extcon framework (so moved to drivers/extcon)
* removed palmas_usb_(write/read) and replaced all calls with
palmas_(read/write).
* ignored a checkpatch warning in the line
static const char *palmas_extcon_cable[] = {
as it seemed to be incorrect?
* removed all references to OMAP in this driver.
* couldn't test this driver with mainline as omap5 panda is not booting
with mainline.
* A comment to change to platform_get_irq from regmap is not done as I felt
the data should come from regmap in this case. Graeme?
Changes from v2:
* Moved the driver to drivers/usb/phy/
* Added a bit more explanation in Kconfig
.../devicetree/bindings/extcon/extcon-twl.txt | 17 +
drivers/extcon/Kconfig | 7 +
drivers/extcon/Makefile | 1 +
drivers/extcon/extcon-palmas.c | 389 ++++++++++++++++++++
include/linux/extcon/extcon_palmas.h | 26 ++
include/linux/mfd/palmas.h | 8 +-
6 files changed, 447 insertions(+), 1 deletion(-)
create mode 100644 Documentation/devicetree/bindings/extcon/extcon-twl.txt
create mode 100644 drivers/extcon/extcon-palmas.c
create mode 100644 include/linux/extcon/extcon_palmas.h
diff --git a/Documentation/devicetree/bindings/extcon/extcon-twl.txt b/Documentation/devicetree/bindings/extcon/extcon-twl.txt
new file mode 100644
index 0000000..a7f6527
--- /dev/null
+++ b/Documentation/devicetree/bindings/extcon/extcon-twl.txt
@@ -0,0 +1,17 @@
+EXTCON FOR TWL CHIPS
+
+PALMAS USB COMPARATOR
+Required Properties:
+ - compatible : Should be "ti,palmas-usb" or "ti,twl6035-usb"
+ - vbus-supply : phandle to the regulator device tree node.
+
+Optional Properties:
+ - ti,wakeup : To enable the wakeup comparator in probe
+ - ti,no_control_vbus: if the platform wishes its own vbus control
+
+palmas-usb {
+ compatible = "ti,twl6035-usb", "ti,palmas-usb";
+ vbus-supply = <&smps10_reg>;
+ ti,wakeup;
+};
+
diff --git a/drivers/extcon/Kconfig b/drivers/extcon/Kconfig
index 5168a13..c881899 100644
--- a/drivers/extcon/Kconfig
+++ b/drivers/extcon/Kconfig
@@ -53,4 +53,11 @@ config EXTCON_ARIZONA
with Wolfson Arizona devices. These are audio CODECs with
advanced audio accessory detection support.
+config EXTCON_PALMAS
+ tristate "Palmas USB EXTCON support"
+ depends on MFD_PALMAS
+ help
+ Say Y here to enable support for USB peripheral and USB host
+ detection by palmas usb.
+
endif # MULTISTATE_SWITCH
diff --git a/drivers/extcon/Makefile b/drivers/extcon/Makefile
index f98a3c4..540e2c3 100644
--- a/drivers/extcon/Makefile
+++ b/drivers/extcon/Makefile
@@ -8,3 +8,4 @@ obj-$(CONFIG_EXTCON_ADC_JACK) += extcon-adc-jack.o
obj-$(CONFIG_EXTCON_MAX77693) += extcon-max77693.o
obj-$(CONFIG_EXTCON_MAX8997) += extcon-max8997.o
obj-$(CONFIG_EXTCON_ARIZONA) += extcon-arizona.o
+obj-$(CONFIG_EXTCON_PALMAS) += extcon-palmas.o
diff --git a/drivers/extcon/extcon-palmas.c b/drivers/extcon/extcon-palmas.c
new file mode 100644
index 0000000..3ef042f
--- /dev/null
+++ b/drivers/extcon/extcon-palmas.c
@@ -0,0 +1,389 @@
+/*
+ * Palmas USB transceiver driver
+ *
+ * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
+ * 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.
+ *
+ * Author: Graeme Gregory <gg@...mlogic.co.uk>
+ * Author: Kishon Vijay Abraham I <kishon@...com>
+ *
+ * Based on twl6030_usb.c
+ *
+ * Author: Hema HK <hemahk@...com>
+ *
+ * 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/init.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/usb/phy_companion.h>
+#include <linux/regulator/consumer.h>
+#include <linux/err.h>
+#include <linux/notifier.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/mfd/palmas.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/extcon/extcon_palmas.h>
+
Remove unnecessary header file. When I remove following header file,
I completed kernel build without any problem.
linux/init.h
linux/io.h
linux/regulator/consumer.h
linux/notifier.h
linux/slab.h
linux/delay.h
hmm.. ok.
+static const char *palmas_extcon_cable[] = {
+ [0] = "USB",
+ [1] = "USB-HOST",
+ NULL,
+};
+
+static const int mutually_exclusive[] = {0x3, 0x0};
+
+static void palmas_usb_wakeup(struct palmas *palmas, int enable)
+{
+ if (enable)
+ palmas_write(palmas, PALMAS_USB_OTG_BASE, PALMAS_USB_WAKEUP,
+ PALMAS_USB_WAKEUP_ID_WK_UP_COMP);
+ else
+ palmas_write(palmas, PALMAS_USB_OTG_BASE, PALMAS_USB_WAKEUP, 0);
+}
+
+static ssize_t palmas_usb_vbus_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ unsigned long flags;
+ int ret = -EINVAL;
+ struct palmas_usb *palmas_usb = dev_get_drvdata(dev);
+
+ spin_lock_irqsave(&palmas_usb->lock, flags);
+
+ switch (palmas_usb->linkstat) {
+ case PALMAS_USB_STATE_VBUS:
+ ret = snprintf(buf, PAGE_SIZE, "vbus\n");
+ break;
+ case PALMAS_USB_STATE_ID:
+ ret = snprintf(buf, PAGE_SIZE, "id\n");
+ break;
+ case PALMAS_USB_STATE_DISCONNECT:
+ ret = snprintf(buf, PAGE_SIZE, "none\n");
+ break;
+ default:
+ ret = snprintf(buf, PAGE_SIZE, "UNKNOWN\n");
+ }
+ spin_unlock_irqrestore(&palmas_usb->lock, flags);
+
+ return ret;
+}
+static DEVICE_ATTR(vbus, 0444, palmas_usb_vbus_show, NULL);
I think that 'palmas_usb_vbus' device attribute isn't standard node
of extcon framework. If you want to check USB/USB-HOST state
on user-space, user process should use following standard node
of extcon instead of 'palmas_usb_vbus' node.
Ok. Makes sense.
- User can get the state of USB/USB-HOST through following node:
/sys/class/extcon/palmas_usb/cable.0/state
if state is 1, PALMAS_USB_STATE_VBUS
if state is 0, PALMAS_USB_STATE_DISCONNECT
/sys/class/extcon/palmas_usb/cable.1/state
if state is 1, PALMAS_USB_STATE_ID
if state is 0, PALMAS_USB_STATE_DISCONNECT
Certainly, extcon driver have to provide specific information of external connector through
standard sysfs entry.
+
+static irqreturn_t palmas_vbus_wakeup_irq(int irq, void *_palmas_usb)
+{
+ int ret;
+ struct palmas_usb *palmas_usb = _palmas_usb;
+ unsigned int vbus_line_state;
+
+ palmas_read(palmas_usb->palmas, PALMAS_INTERRUPT_BASE,
+ PALMAS_INT3_LINE_STATE, &vbus_line_state);
+
+ if (vbus_line_state & PALMAS_INT3_LINE_STATE_VBUS) {
+ if (palmas_usb->linkstat != PALMAS_USB_STATE_VBUS) {
+ if (palmas_usb->vbus_reg) {
+ ret = regulator_enable(palmas_usb->vbus_reg);
+ if (ret) {
+ dev_dbg(palmas_usb->dev,
+ "regulator enable failed\n");
+ goto ret0;
+ }
+ }
+ palmas_usb->linkstat = PALMAS_USB_STATE_VBUS;
+ extcon_set_cable_state(&palmas_usb->edev, "USB", true);
+ } else {
+ dev_dbg(palmas_usb->dev,
+ "Spurious connect event detected\n");
+ }
+ } else if (!(vbus_line_state & PALMAS_INT3_LINE_STATE_VBUS)) {
+ if (palmas_usb->linkstat == PALMAS_USB_STATE_VBUS) {
+ if (palmas_usb->vbus_reg)
+ regulator_disable(palmas_usb->vbus_reg);
+ palmas_usb->linkstat = PALMAS_USB_STATE_DISCONNECT;
+ extcon_set_cable_state(&palmas_usb->edev, "USB", false);
+ } else {
+ dev_dbg(palmas_usb->dev,
+ "Spurious disconnect event detected\n");
+ }
+ }
+
+ret0:
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t palmas_id_wakeup_irq(int irq, void *_palmas_usb)
+{
+ int ret;
+ unsigned int set;
+ struct palmas_usb *palmas_usb = _palmas_usb;
+
+ palmas_read(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
+ PALMAS_USB_ID_INT_LATCH_SET, &set);
+
+ if (set & PALMAS_USB_ID_INT_SRC_ID_GND) {
+ if (palmas_usb->vbus_reg) {
+ ret = regulator_enable(palmas_usb->vbus_reg);
+ if (ret) {
+ dev_dbg(palmas_usb->dev,
+ "regulator enable failed\n");
+ goto ret0;
+ }
+ }
+ palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
+ PALMAS_USB_ID_INT_EN_HI_SET,
+ PALMAS_USB_ID_INT_EN_HI_SET_ID_FLOAT);
+ palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
+ PALMAS_USB_ID_INT_EN_HI_CLR,
+ PALMAS_USB_ID_INT_EN_HI_CLR_ID_GND);
+ palmas_usb->linkstat = PALMAS_USB_STATE_ID;
+ extcon_set_cable_state(&palmas_usb->edev, "USB-HOST", true);
+ } else if (set & PALMAS_USB_ID_INT_SRC_ID_FLOAT) {
+ palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
+ PALMAS_USB_ID_INT_EN_HI_SET,
+ PALMAS_USB_ID_INT_EN_HI_SET_ID_GND);
+ palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
+ PALMAS_USB_ID_INT_EN_HI_CLR,
+ PALMAS_USB_ID_INT_EN_HI_CLR_ID_FLOAT);
+ if (palmas_usb->vbus_reg)
+ regulator_disable(palmas_usb->vbus_reg);
+ palmas_usb->linkstat = PALMAS_USB_STATE_DISCONNECT;
+ extcon_set_cable_state(&palmas_usb->edev, "USB-HOST", false);
+ }
+
+ret0:
+ return IRQ_HANDLED;
+}
+
+static void palmas_enable_irq(struct palmas_usb *palmas_usb)
+{
+ palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
+ PALMAS_USB_VBUS_CTRL_SET,
+ PALMAS_USB_VBUS_CTRL_SET_VBUS_ACT_COMP);
+
+ palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
+ PALMAS_USB_ID_CTRL_SET, PALMAS_USB_ID_CTRL_SET_ID_ACT_COMP);
+
+ palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
+ PALMAS_USB_ID_INT_EN_HI_SET,
+ PALMAS_USB_ID_INT_EN_HI_SET_ID_GND);
+
+ palmas_vbus_wakeup_irq(palmas_usb->irq4, palmas_usb);
+ palmas_id_wakeup_irq(palmas_usb->irq2, palmas_usb);
+}
+
+static void palmas_set_vbus_work(struct work_struct *data)
+{
+ int ret;
+ struct palmas_usb *palmas_usb = container_of(data, struct palmas_usb,
+ set_vbus_work);
+
+ if (IS_ERR_OR_NULL(palmas_usb->vbus_reg)) {
+ dev_err(palmas_usb->dev, "invalid regulator\n");
+ return;
+ }
+
+ /*
+ * Start driving VBUS. Set OPA_MODE bit in CHARGERUSB_CTRL1
+ * register. This enables boost mode.
+ */
+
+ if (palmas_usb->vbus_enable) {
+ ret = regulator_enable(palmas_usb->vbus_reg);
+ if (ret)
+ dev_dbg(palmas_usb->dev, "regulator enable failed\n");
+ } else {
+ regulator_disable(palmas_usb->vbus_reg);
+ }
+}
+
+static int palmas_set_vbus(struct phy_companion *comparator, bool enabled)
+{
+ struct palmas_usb *palmas_usb = comparator_to_palmas(comparator);
+
+ palmas_usb->vbus_enable = enabled;
+ schedule_work(&palmas_usb->set_vbus_work);
+
+ return 0;
+}
+
+static int palmas_start_srp(struct phy_companion *comparator)
+{
+ struct palmas_usb *palmas_usb = comparator_to_palmas(comparator);
+
+ palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
+ PALMAS_USB_VBUS_CTRL_SET, PALMAS_USB_VBUS_CTRL_SET_VBUS_DISCHRG
+ | PALMAS_USB_VBUS_CTRL_SET_VBUS_IADP_SINK);
+ palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
+ PALMAS_USB_VBUS_CTRL_SET,
+ PALMAS_USB_VBUS_CTRL_SET_VBUS_CHRG_VSYS |
+ PALMAS_USB_VBUS_CTRL_SET_VBUS_IADP_SINK);
+
+ mdelay(100);
+
+ palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
+ PALMAS_USB_VBUS_CTRL_CLR,
+ PALMAS_USB_VBUS_CTRL_SET_VBUS_CHRG_VSYS |
+ PALMAS_USB_VBUS_CTRL_SET_VBUS_CHRG_VSYS);
+
+ return 0;
+}
+
+static void palmas_dt_to_pdata(struct device_node *node,
+ struct palmas_usb_platform_data *pdata)
+{
+ pdata->no_control_vbus = of_property_read_bool(node,
+ "ti,no_control_vbus");
+ pdata->wakeup = of_property_read_bool(node, "ti,wakeup");
+}
+
+static int palmas_usb_probe(struct platform_device *pdev)
+{
+ u32 ret;
+ struct palmas *palmas = dev_get_drvdata(pdev->dev.parent);
+ struct palmas_usb_platform_data *pdata = pdev->dev.platform_data;
+ struct device_node *node = pdev->dev.of_node;
+ struct palmas_usb *palmas_usb;
+ int status;
+
+ if (node && !pdata) {
+ pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+
+ if (!pdata)
+ return -ENOMEM;
+
+ palmas_dt_to_pdata(node, pdata);
+ }
+
+ if (!pdata)
+ return -EINVAL;
+
+ palmas_usb = devm_kzalloc(&pdev->dev, sizeof(*palmas_usb), GFP_KERNEL);
+ if (!palmas_usb)
+ return -ENOMEM;
+
+ palmas->usb = palmas_usb;
+ palmas_usb->palmas = palmas;
+
+ palmas_usb->dev = &pdev->dev;
+
+ palmas_usb->irq1 = regmap_irq_get_virq(palmas->irq_data,
+ PALMAS_ID_OTG_IRQ);
+ palmas_usb->irq2 = regmap_irq_get_virq(palmas->irq_data,
+ PALMAS_ID_IRQ);
+ palmas_usb->irq3 = regmap_irq_get_virq(palmas->irq_data,
+ PALMAS_VBUS_OTG_IRQ);
+ palmas_usb->irq4 = regmap_irq_get_virq(palmas->irq_data,
+ PALMAS_VBUS_IRQ);
+
+ palmas_usb->comparator.set_vbus = palmas_set_vbus;
+ palmas_usb->comparator.start_srp = palmas_start_srp;
+
+ palmas_usb_wakeup(palmas, pdata->wakeup);
+
+ /* init spinlock for workqueue */
+ spin_lock_init(&palmas_usb->lock);
+
+ if (!pdata->no_control_vbus) {
+ palmas_usb->vbus_reg = devm_regulator_get(&pdev->dev, "vbus");
+ if (IS_ERR(palmas_usb->vbus_reg)) {
+ dev_err(&pdev->dev, "vbus init failed\n");
+ return PTR_ERR(palmas_usb->vbus_reg);
+ }
+ }
+
+ platform_set_drvdata(pdev, palmas_usb);
+
+ if (device_create_file(&pdev->dev, &dev_attr_vbus))
+ dev_warn(&pdev->dev, "could not create sysfs file\n");
device_create_file() isn't needed if remove 'palmas_usb_vbus' sysfs entry.
right.
+
+ palmas_usb->edev.name = "palmas_usb";
I prefer '-' instead of '_'. change from "palmas_usb" to "palmas-usb".
+ palmas_usb->edev.supported_cable = palmas_extcon_cable;
+ palmas_usb->edev.mutually_exclusive = mutually_exclusive;
+
+ ret = extcon_dev_register(&palmas_usb->edev, palmas_usb->dev);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to register extcon device\n");
+ return ret;
+ }
+
+ /* init spinlock for workqueue */
+ spin_lock_init(&palmas_usb->lock);
+
+ INIT_WORK(&palmas_usb->set_vbus_work, palmas_set_vbus_work);
+
+ status = devm_request_threaded_irq(palmas_usb->dev, palmas_usb->irq2,
+ NULL, palmas_id_wakeup_irq,
+ IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
+ "palmas_usb", palmas_usb);
+ if (status < 0) {
+ dev_err(&pdev->dev, "can't get IRQ %d, err %d\n",
+ palmas_usb->irq2, status);
+ goto fail_irq;
+ }
+
+ status = devm_request_threaded_irq(palmas_usb->dev, palmas_usb->irq4,
+ NULL, palmas_vbus_wakeup_irq,
+ IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
+ "palmas_usb", palmas_usb);
+ if (status < 0) {
+ dev_err(&pdev->dev, "can't get IRQ %d, err %d\n",
+ palmas_usb->irq4, status);
+ goto fail_irq;
+ }
+
+ palmas_enable_irq(palmas_usb);
+
+ return 0;
+
+fail_irq:
+ cancel_work_sync(&palmas_usb->set_vbus_work);
+ device_remove_file(palmas_usb->dev, &dev_attr_vbus);
ditto.
+
+ return status;
+}
+
+static int palmas_usb_remove(struct platform_device *pdev)
+{
+ struct palmas_usb *palmas_usb = platform_get_drvdata(pdev);
+
+ device_remove_file(palmas_usb->dev, &dev_attr_vbus);
ditto.
+ cancel_work_sync(&palmas_usb->set_vbus_work);
+ extcon_dev_unregister(&palmas_usb->edev);
+
+ return 0;
+}
+
+static struct of_device_id of_palmas_match_tbl[] = {
+ { .compatible = "ti,palmas-usb", },
+ { .compatible = "ti,twl6035-usb", },
+ { /* end */ }
+};
+
+static struct platform_driver palmas_usb_driver = {
+ .probe = palmas_usb_probe,
+ .remove = palmas_usb_remove,
+ .driver = {
+ .name = "palmas-usb",
+ .of_match_table = of_palmas_match_tbl,
+ .owner = THIS_MODULE,
+ },
+};
+
+module_platform_driver(palmas_usb_driver);
+
+MODULE_ALIAS("platform:palmas-usb");
+MODULE_AUTHOR("Graeme Gregory <gg@...mlogic.co.uk>");
+MODULE_DESCRIPTION("Palmas USB transceiver driver");
+MODULE_LICENSE("GPL");
+MODULE_DEVICE_TABLE(of, of_palmas_match_tbl);
diff --git a/include/linux/extcon/extcon_palmas.h b/include/linux/extcon/extcon_palmas.h
new file mode 100644
index 0000000..a5119c9
--- /dev/null
+++ b/include/linux/extcon/extcon_palmas.h
@@ -0,0 +1,26 @@
+/*
+ * extcon_palmas.h - palmas extcon driver to detect VBUS or ID events
+ *
+ * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
+ * 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.
+ *
+ * Author: Kishon Vijay Abraham I <kishon@xxxxxx>
+ *
+ * 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.
+ *
+ */
+
+#ifndef __EXTCON_PALMAS_H__
+#define __EXTCON_PALMAS_H__
+
+#define PALMAS_USB_STATE_DISCONNECT 0x0
+#define PALMAS_USB_STATE_VBUS BIT(0)
+#define PALMAS_USB_STATE_ID BIT(1)
+
The defined variable in extcon_palmas.h is used only on extcon-palmas.c.
So, I would like to move definition from extcon_palmas.h to extcon-palmas.c
and remove extcon_palmas.h header file.
Actually it has to be used in dwc3-omap.c (that was in a different patch).
Thanks
Kishon
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