> -----Original Message----- > From: Johan Hovold [mailto:jhovold@xxxxxxxxx] On Behalf Of Johan Hovold > Sent: Monday, September 22, 2014 5:14 PM > To: Muthu Mani > Cc: Samuel Ortiz; Lee Jones; Wolfram Sang; linux-i2c@xxxxxxxxxxxxxxx; Linus > Walleij; Alexandre Courbot; linux-gpio@xxxxxxxxxxxxxxx; > gregkh@xxxxxxxxxxxxxxxxxxx; linux-usb@xxxxxxxxxxxxxxx; linux- > kernel@xxxxxxxxxxxxxxx; Rajaram Regupathy > Subject: Re: [PATCH 3/3] gpio: add support for Cypress CYUSBS234 USB-GPIO > adapter > > On Mon, Sep 22, 2014 at 03:04:18PM +0530, Muthu Mani wrote: > > Adds support for USB-GPIO interface of Cypress Semiconductor > > CYUSBS234 USB-Serial Bridge controller. > > > > The GPIO get/set can be done through vendor command on control > > endpoint. > > > > Details about the device can be found at: > > http://www.cypress.com/?rID=84126 > > > > Signed-off-by: Muthu Mani <muth@xxxxxxxxxxx> > > Signed-off-by: Rajaram Regupathy <rera@xxxxxxxxxxx> > > --- > > drivers/gpio/Kconfig | 13 +++ > > drivers/gpio/Makefile | 1 + > > drivers/gpio/gpio-cyusbs23x.c | 190 > > ++++++++++++++++++++++++++++++++++++++++++ > > 3 files changed, 204 insertions(+) > > create mode 100644 drivers/gpio/gpio-cyusbs23x.c > > > > diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index > > 9de1515..932e07c 100644 > > --- a/drivers/gpio/Kconfig > > +++ b/drivers/gpio/Kconfig > > @@ -886,6 +886,19 @@ config GPIO_BCM_KONA > > > > comment "USB GPIO expanders:" > > > > +config GPIO_CYUSBS23X > > + tristate "CYUSBS23x GPIO support" > > + depends on MFD_CYUSBS23X && USB > > + help > > + Say yes here to access the GPIO signals of Cypress > > + Semiconductor CYUSBS23x USB Serial Bridge Controller. > > + > > + This driver enables the GPIO interface of CYUSBS23x USB Serial > > + Bridge controller. > > + > > + This driver can also be built as a module. If so, the module will be > > + called gpio-cyusbs23x. > > + > > config GPIO_VIPERBOARD > > tristate "Viperboard GPIO a & b support" > > depends on MFD_VIPERBOARD && USB diff --git > > a/drivers/gpio/Makefile b/drivers/gpio/Makefile index 5d024e3..3ad89f1 > > 100644 > > --- a/drivers/gpio/Makefile > > +++ b/drivers/gpio/Makefile > > @@ -23,6 +23,7 @@ obj-$(CONFIG_GPIO_BT8XX) += gpio-bt8xx.o > > obj-$(CONFIG_GPIO_CLPS711X) += gpio-clps711x.o > > obj-$(CONFIG_GPIO_CS5535) += gpio-cs5535.o > > obj-$(CONFIG_GPIO_CRYSTAL_COVE) += gpio-crystalcove.o > > +obj-$(CONFIG_GPIO_CYUSBS23X) += gpio-cyusbs23x.o > > obj-$(CONFIG_GPIO_DA9052) += gpio-da9052.o > > obj-$(CONFIG_GPIO_DA9055) += gpio-da9055.o > > obj-$(CONFIG_GPIO_DAVINCI) += gpio-davinci.o > > diff --git a/drivers/gpio/gpio-cyusbs23x.c > > b/drivers/gpio/gpio-cyusbs23x.c new file mode 100644 index > > 0000000..8aa3ab6 > > --- /dev/null > > +++ b/drivers/gpio/gpio-cyusbs23x.c > > @@ -0,0 +1,190 @@ > > +/* > > + * Cypress USB-Serial Bridge Controller GPIO driver > > + * > > + * Copyright (c) 2014 Cypress Semiconductor Corporation. > > + * > > + * Author: > > + * Muthu Mani <muth@xxxxxxxxxxx> > > + * > > + * Additional contributors include: > > + * Rajaram Regupathy <rera@xxxxxxxxxxx> > > + * > > + * This program is free software; you can redistribute it and/or > > +modify it > > + * under the terms of the GNU General Public License version 2 as > > +published by > > + * the Free Software Foundation. > > + */ > > + > > +#include <linux/kernel.h> > > +#include <linux/errno.h> > > +#include <linux/module.h> > > +#include <linux/slab.h> > > +#include <linux/types.h> > > +#include <linux/mutex.h> > > +#include <linux/platform_device.h> > > + > > +#include <linux/usb.h> > > +#include <linux/gpio.h> > > + > > +#include <linux/mfd/cyusbs23x.h> > > + > > +#define CY_GPIO_GET_LEN (2) > > + > > +struct cyusbs_gpio { > > + struct gpio_chip gpio; > > + struct cyusbs23x *cyusbs; > > +}; > > + > > +static int cy_gpio_get(struct gpio_chip *chip, > > + unsigned offset) { > > + int ret; > > + char buf[CY_GPIO_GET_LEN]; > > Buffers used for USB (DMA) transfers cannot be allocated on the stack. > Use kmalloc and friends. Ok, will update it. > > > + __u16 wIndex, wValue; > > u16 throughout. Ok. > > > + struct cyusbs_gpio *gpio = > > + container_of(chip, struct cyusbs_gpio, gpio); > > + struct cyusbs23x *cyusbs = gpio->cyusbs; > > + > > + dev_dbg(&cyusbs->usb_intf->dev, "%s: %d\n", __func__, > > + offset); > > + wValue = offset; > > + wIndex = 0; > > + > > + mutex_lock(&cyusbs->lock); > > + ret = usb_control_msg(cyusbs->usb_dev, > > + usb_rcvctrlpipe(cyusbs->usb_dev, 0), > > + CY_GPIO_GET_VALUE_CMD, > > + USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN, > > + wValue, wIndex, buf, CY_GPIO_GET_LEN, 2000); > > + mutex_unlock(&cyusbs->lock); > > + > > + dev_dbg(&cyusbs->usb_intf->dev, "%s: %d %02x %02x\n", __func__, > > + ret, buf[0], buf[1]); > > + > > + if (ret == CY_GPIO_GET_LEN) { > > + if (buf[0] == 0) > > + ret = buf[1]; > > + else > > + ret = -EINVAL; > > + } else { > > + ret = -EREMOTEIO; > > + } > > + > > + return ret; > > +} > > + > > +static void cy_gpio_set(struct gpio_chip *chip, > > + unsigned offset, int value) { > > + int ret; > > + __u16 wIndex, wValue; > > + struct cyusbs_gpio *gpio = > > + container_of(chip, struct cyusbs_gpio, gpio); > > + struct cyusbs23x *cyusbs = gpio->cyusbs; > > + > > + dev_dbg(&cyusbs->usb_intf->dev, "%s: %d\n", __func__, > > + offset); > > + wValue = offset; > > + wIndex = value; > > + > > + mutex_lock(&cyusbs->lock); > > + ret = usb_control_msg(cyusbs->usb_dev, > > + usb_sndctrlpipe(cyusbs->usb_dev, 0), > > + CY_GPIO_SET_VALUE_CMD, > > + USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN, > > + wValue, wIndex, NULL, 0, 2000); > > + mutex_unlock(&cyusbs->lock); > > + > > + if (ret < 0) > > + dev_err(&cyusbs->usb_intf->dev, "error setting > > +gpio:%d\n", ret); } > > + > > +static int cy_gpio_direction_input(struct gpio_chip *chip, > > + unsigned offset) { > > + return 0; > > Aren't the GPIOs output-only? No. > > > +} > > + > > +static int cy_gpio_direction_output(struct gpio_chip *chip, > > + unsigned offset, int value) { > > + return 0; > > +} > > + > > +static int cyusbs23x_gpio_probe(struct platform_device *pdev) { > > + struct cyusbs23x *cyusbs; > > + struct cyusbs_gpio *cy_gpio; > > + int ret = 0; > > + > > + dev_dbg(&pdev->dev, "%s\n", __func__); > > + > > + cyusbs = dev_get_drvdata(pdev->dev.parent); > > + > > + cy_gpio = devm_kzalloc(&pdev->dev, sizeof(*cy_gpio), GFP_KERNEL); > > + if (cy_gpio == NULL) > > + return -ENOMEM; > > + > > + cy_gpio->cyusbs = cyusbs; > > + /* registering gpio */ > > + cy_gpio->gpio.label = "cyusbs23x gpio"; > > + cy_gpio->gpio.dev = &pdev->dev; > > + cy_gpio->gpio.owner = THIS_MODULE; > > + cy_gpio->gpio.base = -1; > > + cy_gpio->gpio.ngpio = 12; /* total GPIOs */ > > I think you need to read out the gpio config from the device eeprom and > implement a request() callback where you verify that a requested gpio is > actually available (mode dependent, and there are never more than 10 gpios > availble). In this initial driver, all GPIOs are made available to user space. Additional functionalities will be added in the next version of the driver. > > > + cy_gpio->gpio.can_sleep = true; > > + cy_gpio->gpio.set = cy_gpio_set; > > + cy_gpio->gpio.get = cy_gpio_get; > > + cy_gpio->gpio.direction_input = cy_gpio_direction_input; > > + cy_gpio->gpio.direction_output = cy_gpio_direction_output; > > + ret = gpiochip_add(&cy_gpio->gpio); > > + if (ret < 0) { > > + dev_err(cy_gpio->gpio.dev, "could not add gpio"); > > + goto error; > > + } > > + > > + platform_set_drvdata(pdev, cy_gpio); > > + > > + dev_dbg(&pdev->dev, "added GPIO\n"); > > + return ret; > > + > > +error: > > + dev_dbg(&pdev->dev, "error occured %d\n", ret); > > + return ret; > > +} > > + > > +static int cyusbs23x_gpio_remove(struct platform_device *pdev) { > > + struct cyusbs_gpio *cy_gpio = platform_get_drvdata(pdev); > > + > > + dev_dbg(&pdev->dev, "%s\n", __func__); > > + > > + gpiochip_remove(&cy_gpio->gpio); > > + > > + return 0; > > +} > > + > > +static struct platform_driver cyusbs23x_gpio_driver = { > > + .driver.name = "cyusbs23x-gpio", > > + .driver.owner = THIS_MODULE, > > + .probe = cyusbs23x_gpio_probe, > > + .remove = cyusbs23x_gpio_remove, > > +}; > > + > > +static int __init cyusbs23x_gpio_init(void) { > > + return platform_driver_register(&cyusbs23x_gpio_driver); > > +} > > +subsys_initcall(cyusbs23x_gpio_init); > > + > > +static void __exit cyusbs23x_gpio_exit(void) { > > + platform_driver_unregister(&cyusbs23x_gpio_driver); > > +} > > +module_exit(cyusbs23x_gpio_exit); > > module_platform_driver Ok. > > > + > > +MODULE_AUTHOR("Rajaram Regupathy <rera@xxxxxxxxxxx>"); > > +MODULE_AUTHOR("Muthu Mani <muth@xxxxxxxxxxx>"); > > +MODULE_DESCRIPTION("gpio-cyusbs23x driver v0.1"); > > +MODULE_LICENSE("GPL"); > > Description and license comments from i2c patch apply here as well. Ok, will update it. > > > +MODULE_ALIAS("platform:cyusbs23x-gpio"); > > + > > Stray new line. Ok, will remove it. I will send the v2 patch soon. > > Johan -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
