Re: [PATCH v5 2/3] extcon: Palmas Extcon Driver

From: Chanwoo Choi
Date: Mon May 27 2013 - 01:35:08 EST

Hi Kishon,

I have some comment about this patch
and upload modified patch to following repository (extcon-for-palmas).
- http://git.kernel.org/cgit/linux/kernel/git/chanwoo/extcon.git/commit/?h=extcon-for-palmas&id=f2b7cb80699cbe1a5fd6c97ef2c600915f8d7f2c

This patchset include patch related to other module
,so I need your opinion to apply this patchset to git repository.

On 05/24/2013 11:31 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>
> Signed-off-by: George Cherian <george.cherian@xxxxxx>
> [kishon@xxxxxx: adapted palmas usb driver to use the extcon framework]
> Signed-off-by: Sebastien Guiriec <s-guiriec@xxxxxx>
> ---
> Changes from v4:
> * removed no_control_vbus property (to be used if the platform wants to use
> its own vbus control.
> * removed unnecessary headers
> * moved the palmas_usb_state to palmas.h
> * misc cleanups
> *A checkpatch warning "WARNING: static const char * array should
> probably be static const char * const"is ignored since it introduces a
> compilation warning.
> 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 | 16 +
> drivers/extcon/Kconfig | 7 +
> drivers/extcon/Makefile | 1 +
> drivers/extcon/extcon-palmas.c | 341 +++++++++++++++++++++
> include/linux/mfd/palmas.h | 25 +-
> 5 files changed, 380 insertions(+), 10 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/extcon/extcon-twl.txt
> create mode 100644 drivers/extcon/extcon-palmas.c
>
> diff --git a/Documentation/devicetree/bindings/extcon/extcon-twl.txt b/Documentation/devicetree/bindings/extcon/extcon-twl.txt
> new file mode 100644
> index 0000000..8ffdeed
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/extcon/extcon-twl.txt
> @@ -0,0 +1,15 @@
> +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
> +
> +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 3297301..63f454e 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
You should add REGULATOR_PALMAS dependency because
palmas_set_switch_smps10() is defined in palmas regulator driver.

+ depends on MFD_PALMAS && REGULATOR_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..9e613e9
> --- /dev/null
> +++ b/drivers/extcon/extcon-palmas.c
> @@ -0,0 +1,341 @@
> +/*
> + * 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@xxxxxxxxxxxxxxx>
> + * Author: Kishon Vijay Abraham I <kishon@xxxxxx>
> + *
> + * Based on twl6030_usb.c
> + *
> + * Author: Hema HK <hemahk@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.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/interrupt.h>
> +#include <linux/platform_device.h>
> +#include <linux/usb/phy_companion.h>
> +#include <linux/err.h>
> +#include <linux/mfd/palmas.h>
> +#include <linux/of.h>
> +#include <linux/of_platform.h>
> +
> +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 irqreturn_t palmas_vbus_irq_handler(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;

I prefer to use consistent name of goto statement becuase you use
'fail_' prefix in palmas_usb_probe()
- goto ret0;
+ goto fail;

> + }
> + }
> + 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:
ditto.

-ret0:
+fail:
> + return IRQ_HANDLED;
> +}
> +
> +static irqreturn_t palmas_id_irq_handler(int irq, void *_palmas_usb)
> +{
> + int ret;
> + unsigned int set;
> + struct palmas_usb *palmas_usb = _palmas_usb;
You should use space instead of tab when defined local variables.

+ 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) {
> + palmas_set_switch_smps10(palmas_usb->palmas, 1);
> + 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;

ditto.

> + }
> + }
> + 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_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
> + PALMAS_USB_ID_INT_LATCH_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);
> + palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
> + PALMAS_USB_ID_INT_LATCH_CLR,
> + PALMAS_USB_ID_INT_EN_HI_CLR_ID_FLOAT);
> + if (palmas_usb->vbus_reg)
> + regulator_disable(palmas_usb->vbus_reg);
> + palmas_set_switch_smps10(palmas_usb->palmas, 0);
> + palmas_usb->linkstat = PALMAS_USB_STATE_DISCONNECT;
> + extcon_set_cable_state(&palmas_usb->edev, "USB-HOST", false);
> + }
> +
> +ret0:

ditto.

> + 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_irq_handler(palmas_usb->vbus_irq, palmas_usb);
> +
> + /* cold plug for host mode needs this delay */
> + msleep(30);
> + palmas_id_irq_handler(palmas_usb->id_irq, 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);
> +
> + /*
> + * 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);
> +
> + msleep(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 int palmas_usb_probe(struct platform_device *pdev)
> +{
> + 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;
> +
> + pdata->wakeup = of_property_read_bool(node, "ti,wakeup");
> + }
> +
> + if (!pdata)
> + return -EINVAL;
I think that if condition of first if statement is true,
second if statement is unnecessary. So, I prefer
to modify if/else statement as following:

+ } else 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;

You should use space instead of tab when assign some value to variables.

+ palmas->usb = palmas_usb;
+ palmas_usb->palmas = palmas;
+
+ palmas_usb->dev= &pdev->dev;


> +
> + palmas_usb->id_otg_irq = regmap_irq_get_virq(palmas->irq_data,
> + PALMAS_ID_OTG_IRQ);
> + palmas_usb->id_irq = regmap_irq_get_virq(palmas->irq_data,
> + PALMAS_ID_IRQ);
> + palmas_usb->vbus_otg_irq = regmap_irq_get_virq(palmas->irq_data,
> + PALMAS_VBUS_OTG_IRQ);
> + palmas_usb->vbus_irq = 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);
> +
> + 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);
> + }
> +
> + INIT_WORK(&palmas_usb->set_vbus_work, palmas_set_vbus_work);
> +
> + platform_set_drvdata(pdev, palmas_usb);
> +
> + palmas_usb->edev.name = "palmas-usb";
> + palmas_usb->edev.supported_cable = palmas_extcon_cable;
> + palmas_usb->edev.mutually_exclusive = mutually_exclusive;
> +
> + status = extcon_dev_register(&palmas_usb->edev, palmas_usb->dev);
> + if (status) {
> + dev_err(&pdev->dev, "failed to register extcon device\n");
> + goto fail_irq;
> + }
> +
> + status = devm_request_threaded_irq(palmas_usb->dev, palmas_usb->id_irq,
> + NULL, palmas_id_irq_handler,
> + IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
> + "palmas_usb_id", palmas_usb);
> + if (status < 0) {
> + dev_err(&pdev->dev, "can't get IRQ %d, err %d\n",
> + palmas_usb->id_irq, status);
> + goto fail_extcon;
> + }
> +
> + status = devm_request_threaded_irq(palmas_usb->dev,
> + palmas_usb->vbus_irq, NULL, palmas_vbus_irq_handler,
> + IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
> + "palmas_usb_vbus", palmas_usb);
> + if (status < 0) {
> + dev_err(&pdev->dev, "can't get IRQ %d, err %d\n",
> + palmas_usb->vbus_irq, status);
> + goto fail_extcon;
> + }
> +
> + palmas_enable_irq(palmas_usb);
> +
> + return 0;
> +
> +fail_extcon:
> + extcon_dev_unregister(&palmas_usb->edev);
> +
> +fail_irq:
> + cancel_work_sync(&palmas_usb->set_vbus_work);
> +
> + return status;
> +}
> +
> +static int palmas_usb_remove(struct platform_device *pdev)
> +{
> + struct palmas_usb *palmas_usb = platform_get_drvdata(pdev);
> +
> + 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@xxxxxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("Palmas USB transceiver driver");
> +MODULE_LICENSE("GPL");
> +MODULE_DEVICE_TABLE(of, of_palmas_match_tbl);
> diff --git a/include/linux/mfd/palmas.h b/include/linux/mfd/palmas.h
> index 6df375d..eb4846b 100644
> --- a/include/linux/mfd/palmas.h
> +++ b/include/linux/mfd/palmas.h
> @@ -20,6 +20,8 @@
> #include <linux/leds.h>
> #include <linux/regmap.h>
> #include <linux/regulator/driver.h>
> +#include <linux/extcon.h>
> +#include <linux/usb/phy_companion.h>
>
> #define PALMAS_NUM_CLIENTS 3
>
> @@ -37,6 +39,12 @@ struct palmas_gpadc;
> struct palmas_resource;
> struct palmas_usb;
>
> +enum palmas_usb_state {
> + PALMAS_USB_STATE_DISCONNECT,
> + PALMAS_USB_STATE_VBUS,
> + PALMAS_USB_STATE_ID,
> +};
> +
> struct palmas {
> struct device *dev;
>
> @@ -180,9 +188,6 @@ struct palmas_pmic_platform_data {
> };
>
> struct palmas_usb_platform_data {
> - /* Set this if platform wishes its own vbus control */
> - int no_control_vbus;
> -
> /* Do we enable the wakeup comparator on probe */
> int wakeup;
> };
> @@ -350,22 +355,22 @@ struct palmas_usb {
> struct palmas *palmas;
> struct device *dev;
>
> - /* for vbus reporting with irqs disabled */
> - spinlock_t lock;
> + struct extcon_dev edev;
> + struct phy_companion comparator;
>
> struct regulator *vbus_reg;
>
> /* used to set vbus, in atomic path */
> struct work_struct set_vbus_work;
>
> - int irq1;
> - int irq2;
> - int irq3;
> - int irq4;
> + int id_otg_irq;
> + int id_irq;
> + int vbus_otg_irq;
> + int vbus_irq;
>
> int vbus_enable;
>
> - u8 linkstat;
> + enum palmas_usb_state linkstat;
> };
>
> #define comparator_to_palmas(x) container_of((x), struct palmas_usb, comparator)

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