From mboxrd@z Thu Jan 1 00:00:00 1970 From: Cyril Chemparathy Subject: [PATCH v8 03/11] gpio: add ti-ssp gpio driver Date: Tue, 18 Jan 2011 14:21:37 -0500 Message-ID: <1295378505-15221-4-git-send-email-cyril@ti.com> References: <1295378505-15221-1-git-send-email-cyril@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: c-park-l0cyMroinI0@public.gmane.org, Cyril Chemparathy , linux-arm-kernel-xIg/pKzrS19vn6HldHNs0ANdhmdF6hFW@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: davinci-linux-open-source-VycZQUHpC/PFrsHnngEfi1aTQe2KTcn/@public.gmane.org, spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, sameo-VuQAYsv1563Yd54FQh9/CA@public.gmane.org, rpurdie-Fm38FmjxZ/leoWH0uzbU5w@public.gmane.org, dbrownell-Rn4VEauK+AKRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Return-path: In-Reply-To: <1295378505-15221-1-git-send-email-cyril-l0cyMroinI0@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: spi-devel-general-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: linux-spi.vger.kernel.org TI's SSP controller pins can be directly read and written to behave like a GPIO. This patch adds a GPIO driver that exposes such functionality. Signed-off-by: Cyril Chemparathy --- drivers/gpio/Kconfig | 10 ++ drivers/gpio/Makefile | 1 + drivers/gpio/ti-ssp-gpio.c | 207 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/mfd/ti_ssp.h | 4 + 4 files changed, 222 insertions(+), 0 deletions(-) create mode 100644 drivers/gpio/ti-ssp-gpio.c diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index 3143ac7..05bbe4c 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -128,6 +128,16 @@ config GPIO_VX855 additional drivers must be enabled in order to use the functionality of the device. +config GPIO_TI_SSP + tristate "TI Sequencer Serial Port - GPIO Support" + depends on MFD_TI_SSP + help + Say yes here to support a GPIO interface on TI SSP port pins. + Each SSP port translates into 4 GPIOs. + + This driver can also be built as a module. If so, the module + will be called ti-ssp-gpio. + comment "I2C GPIO expanders:" config GPIO_MAX7300 diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index bdf3dde..0e2a844 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -26,6 +26,7 @@ obj-$(CONFIG_GPIO_PL061) += pl061.o obj-$(CONFIG_GPIO_STMPE) += stmpe-gpio.o obj-$(CONFIG_GPIO_TC35892) += tc35892-gpio.o obj-$(CONFIG_GPIO_TIMBERDALE) += timbgpio.o +obj-$(CONFIG_GPIO_TI_SSP) += ti-ssp-gpio.o obj-$(CONFIG_GPIO_TWL4030) += twl4030-gpio.o obj-$(CONFIG_GPIO_UCB1400) += ucb1400_gpio.o obj-$(CONFIG_GPIO_XILINX) += xilinx_gpio.o diff --git a/drivers/gpio/ti-ssp-gpio.c b/drivers/gpio/ti-ssp-gpio.c new file mode 100644 index 0000000..edc3142 --- /dev/null +++ b/drivers/gpio/ti-ssp-gpio.c @@ -0,0 +1,207 @@ +/* + * Sequencer Serial Port (SSP) based virtual GPIO driver + * + * Copyright (C) 2010 Texas Instruments Inc + * + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +struct ti_ssp_gpio_chip { + struct gpio_chip chip; + struct device *dev; + spinlock_t lock; + u8 out; + u32 iosel; +}; + +#define to_ssp_gpio_chip(c) container_of(c, struct ti_ssp_gpio_chip, chip) + +static int ti_ssp_gpio_dir_in(struct gpio_chip *chip, unsigned gpio_num) +{ + struct ti_ssp_gpio_chip *gpio = to_ssp_gpio_chip(chip); + int error = 0; + + spin_lock(&gpio->lock); + + gpio->iosel &= ~SSP_PIN_MASK(gpio_num); + gpio->iosel |= SSP_PIN_SEL(gpio_num, SSP_IN); + + error = ti_ssp_set_iosel(gpio->dev, gpio->iosel); + + spin_unlock(&gpio->lock); + + return error; +} + +static int ti_ssp_gpio_dir_out(struct gpio_chip *chip, unsigned gpio_num, + int val) +{ + struct ti_ssp_gpio_chip *gpio = to_ssp_gpio_chip(chip); + int error; + + spin_lock(&gpio->lock); + + gpio->iosel &= ~SSP_PIN_MASK(gpio_num); + gpio->iosel |= SSP_PIN_SEL(gpio_num, SSP_OUT); + + error = ti_ssp_set_iosel(gpio->dev, gpio->iosel); + + if (error < 0) + goto error; + + if (val) + gpio->out |= BIT(gpio_num); + else + gpio->out &= ~BIT(gpio_num); + + error = ti_ssp_raw_write(gpio->dev, gpio->out); + +error: + spin_unlock(&gpio->lock); + return error; +} + +static int ti_ssp_gpio_get(struct gpio_chip *chip, unsigned gpio_num) +{ + struct ti_ssp_gpio_chip *gpio = to_ssp_gpio_chip(chip); + int ret; + + spin_lock(&gpio->lock); + + ret = ti_ssp_raw_read(gpio->dev); + if (ret >= 0) + ret = !!(ret & BIT(gpio_num)); + + spin_unlock(&gpio->lock); + return ret; +} + +static void ti_ssp_gpio_set(struct gpio_chip *chip, unsigned gpio_num, int val) +{ + struct ti_ssp_gpio_chip *gpio = to_ssp_gpio_chip(chip); + + spin_lock(&gpio->lock); + + if (val) + gpio->out |= BIT(gpio_num); + else + gpio->out &= ~BIT(gpio_num); + + ti_ssp_raw_write(gpio->dev, gpio->out); + + spin_unlock(&gpio->lock); +} + +static int __devinit ti_ssp_gpio_probe(struct platform_device *pdev) +{ + const struct ti_ssp_gpio_data *pdata = pdev->dev.platform_data; + struct device *dev = &pdev->dev; + struct ti_ssp_gpio_chip *gpio; + int error; + + if (!pdata) { + dev_err(dev, "platform data not found\n"); + return -EINVAL; + } + + gpio = kzalloc(sizeof(*gpio), GFP_KERNEL); + if (!gpio) { + dev_err(dev, "cannot allocate driver data\n"); + return -ENOMEM; + } + + gpio->dev = dev; + gpio->iosel = SSP_PIN_SEL(0, SSP_IN) | SSP_PIN_SEL(1, SSP_IN) | + SSP_PIN_SEL(2, SSP_IN) | SSP_PIN_SEL(3, SSP_IN); + error = ti_ssp_set_iosel(gpio->dev, gpio->iosel); + if (error < 0) { + dev_err(dev, "gpio io setup failed (%d)\n", error); + goto error; + } + + spin_lock_init(&gpio->lock); + platform_set_drvdata(pdev, gpio); + + gpio->chip.base = pdata->start; + gpio->chip.ngpio = 4; + gpio->chip.dev = &pdev->dev; + gpio->chip.label = "ti_ssp_gpio"; + gpio->chip.owner = THIS_MODULE; + gpio->chip.get = ti_ssp_gpio_get; + gpio->chip.set = ti_ssp_gpio_set; + gpio->chip.direction_input = ti_ssp_gpio_dir_in; + gpio->chip.direction_output = ti_ssp_gpio_dir_out; + + error = gpiochip_add(&gpio->chip); + if (error < 0) { + dev_err(dev, "gpio chip registration failed (%d)\n", error); + goto error; + } + + dev_info(dev, "ssp gpio interface registered\n"); + return 0; + +error: + kfree(gpio); + return error; +} + +static int __devexit ti_ssp_gpio_remove(struct platform_device *pdev) +{ + struct ti_ssp_gpio_chip *gpio = platform_get_drvdata(pdev); + int error; + + error = gpiochip_remove(&gpio->chip); + if (error < 0) + return error; + kfree(gpio); + return 0; +} + +static struct platform_driver ti_ssp_gpio_driver = { + .probe = ti_ssp_gpio_probe, + .remove = __devexit_p(ti_ssp_gpio_remove), + .driver = { + .name = "ti-ssp-gpio", + .owner = THIS_MODULE, + }, +}; + +static int __init ti_ssp_gpio_init(void) +{ + return platform_driver_register(&ti_ssp_gpio_driver); +} +module_init(ti_ssp_gpio_init); + +static void __exit ti_ssp_gpio_exit(void) +{ + platform_driver_unregister(&ti_ssp_gpio_driver); +} +module_exit(ti_ssp_gpio_exit); + +MODULE_DESCRIPTION("GPIO interface for TI-SSP"); +MODULE_AUTHOR("Cyril Chemparathy "); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:ti-ssp-gpio"); diff --git a/include/linux/mfd/ti_ssp.h b/include/linux/mfd/ti_ssp.h index dbb4b43..10c65bb 100644 --- a/include/linux/mfd/ti_ssp.h +++ b/include/linux/mfd/ti_ssp.h @@ -38,6 +38,10 @@ struct ti_ssp_spi_data { void (*select)(int cs); }; +struct ti_ssp_gpio_data { + int start; +}; + /* * Sequencer port IO pin configuration bits. 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