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

[Chanwoo Choi <cw00.choi@samsung.com>]

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@slimlogic.co.uk>
>
> 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@slimlogic.co.uk>
> Signed-off-by: Moiz Sonasath <m-sonasath@ti.com>
> Signed-off-by: Ruchika Kharwar <ruchika@ti.com>
> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
> Signed-off-by: George Cherian <george.cherian@ti.com>
> [kishon@ti.com: adapted palmas usb driver to use the extcon framework]
> Signed-off-by: Sebastien Guiriec <s-guiriec@ti.com>
> ---
> 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@slimlogic.co.uk>
> + * Author: Kishon Vijay Abraham I <kishon@ti.com>
> + *
> + * Based on twl6030_usb.c
> + *
> + * Author: Hema HK <hemahk@ti.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/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@slimlogic.co.uk>");
> +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)