From: Ira W. Snyder Date: Wed, 7 Apr 2010 08:08:01 +0000 (+0200) Subject: gpio: Add support for Janz VMOD-TTL Digital IO module X-Git-Tag: v2.6.35-rc1~7^2~31 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=800e69fbd2faea906cabd10ddb77e36410f2bd9c;p=karo-tx-linux.git gpio: Add support for Janz VMOD-TTL Digital IO module The Janz VMOD-TTL is a MODULbus daughterboard which fits onto any MODULbus carrier board. It essentially consists of some various logic and a Zilog Z8536 CIO Counter/Timer and Parallel IO Unit. The board must be physically configured with jumpers to enable a user to drive output signals. I am only interested in outputs, so I have made this driver as simple as possible. It only supports a very minimal subset of the features provided by the Z8536 chip. Signed-off-by: Ira W. Snyder Signed-off-by: Samuel Ortiz --- diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index 56eb0c59c512..0e9c16b5bbce 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -325,4 +325,14 @@ config GPIO_UCB1400 To compile this driver as a module, choose M here: the module will be called ucb1400_gpio. +comment "MODULbus GPIO expanders:" + +config GPIO_JANZ_TTL + tristate "Janz VMOD-TTL Digital IO Module" + depends on MFD_JANZ_CMODIO + help + This enables support for the Janz VMOD-TTL Digital IO module. + This driver provides support for driving the pins in output + mode only. Input mode is not supported. + endif diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index d3226d395a90..94a96c51c741 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -29,3 +29,4 @@ obj-$(CONFIG_GPIO_WM8350) += wm8350-gpiolib.o obj-$(CONFIG_GPIO_WM8994) += wm8994-gpio.o obj-$(CONFIG_GPIO_SCH) += sch_gpio.o obj-$(CONFIG_GPIO_RDC321X) += rdc321x-gpio.o +obj-$(CONFIG_GPIO_JANZ_TTL) += janz-ttl.o diff --git a/drivers/gpio/janz-ttl.c b/drivers/gpio/janz-ttl.c new file mode 100644 index 000000000000..813ac077e5d7 --- /dev/null +++ b/drivers/gpio/janz-ttl.c @@ -0,0 +1,258 @@ +/* + * Janz MODULbus VMOD-TTL GPIO Driver + * + * Copyright (c) 2010 Ira W. Snyder + * + * 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. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#define DRV_NAME "janz-ttl" + +#define PORTA_DIRECTION 0x23 +#define PORTB_DIRECTION 0x2B +#define PORTC_DIRECTION 0x06 +#define PORTA_IOCTL 0x24 +#define PORTB_IOCTL 0x2C +#define PORTC_IOCTL 0x07 + +#define MASTER_INT_CTL 0x00 +#define MASTER_CONF_CTL 0x01 + +#define CONF_PAE (1 << 2) +#define CONF_PBE (1 << 7) +#define CONF_PCE (1 << 4) + +struct ttl_control_regs { + __be16 portc; + __be16 portb; + __be16 porta; + __be16 control; +}; + +struct ttl_module { + struct gpio_chip gpio; + + /* base address of registers */ + struct ttl_control_regs __iomem *regs; + + u8 portc_shadow; + u8 portb_shadow; + u8 porta_shadow; + + spinlock_t lock; +}; + +static int ttl_get_value(struct gpio_chip *gpio, unsigned offset) +{ + struct ttl_module *mod = dev_get_drvdata(gpio->dev); + u8 *shadow; + int ret; + + if (offset < 8) { + shadow = &mod->porta_shadow; + } else if (offset < 16) { + shadow = &mod->portb_shadow; + offset -= 8; + } else { + shadow = &mod->portc_shadow; + offset -= 16; + } + + spin_lock(&mod->lock); + ret = *shadow & (1 << offset); + spin_unlock(&mod->lock); + return ret; +} + +static void ttl_set_value(struct gpio_chip *gpio, unsigned offset, int value) +{ + struct ttl_module *mod = dev_get_drvdata(gpio->dev); + void __iomem *port; + u8 *shadow; + + if (offset < 8) { + port = &mod->regs->porta; + shadow = &mod->porta_shadow; + } else if (offset < 16) { + port = &mod->regs->portb; + shadow = &mod->portb_shadow; + offset -= 8; + } else { + port = &mod->regs->portc; + shadow = &mod->portc_shadow; + offset -= 16; + } + + spin_lock(&mod->lock); + if (value) + *shadow |= (1 << offset); + else + *shadow &= ~(1 << offset); + + iowrite16be(*shadow, port); + spin_unlock(&mod->lock); +} + +static void __devinit ttl_write_reg(struct ttl_module *mod, u8 reg, u16 val) +{ + iowrite16be(reg, &mod->regs->control); + iowrite16be(val, &mod->regs->control); +} + +static void __devinit ttl_setup_device(struct ttl_module *mod) +{ + /* reset the device to a known state */ + iowrite16be(0x0000, &mod->regs->control); + iowrite16be(0x0001, &mod->regs->control); + iowrite16be(0x0000, &mod->regs->control); + + /* put all ports in open-drain mode */ + ttl_write_reg(mod, PORTA_IOCTL, 0x00ff); + ttl_write_reg(mod, PORTB_IOCTL, 0x00ff); + ttl_write_reg(mod, PORTC_IOCTL, 0x000f); + + /* set all ports as outputs */ + ttl_write_reg(mod, PORTA_DIRECTION, 0x0000); + ttl_write_reg(mod, PORTB_DIRECTION, 0x0000); + ttl_write_reg(mod, PORTC_DIRECTION, 0x0000); + + /* set all ports to drive zeroes */ + iowrite16be(0x0000, &mod->regs->porta); + iowrite16be(0x0000, &mod->regs->portb); + iowrite16be(0x0000, &mod->regs->portc); + + /* enable all ports */ + ttl_write_reg(mod, MASTER_CONF_CTL, CONF_PAE | CONF_PBE | CONF_PCE); +} + +static int __devinit ttl_probe(struct platform_device *pdev) +{ + struct janz_platform_data *pdata; + struct device *dev = &pdev->dev; + struct ttl_module *mod; + struct gpio_chip *gpio; + struct resource *res; + int ret; + + pdata = pdev->dev.platform_data; + if (!pdata) { + dev_err(dev, "no platform data\n"); + ret = -ENXIO; + goto out_return; + } + + mod = kzalloc(sizeof(*mod), GFP_KERNEL); + if (!mod) { + dev_err(dev, "unable to allocate private data\n"); + ret = -ENOMEM; + goto out_return; + } + + platform_set_drvdata(pdev, mod); + spin_lock_init(&mod->lock); + + /* get access to the MODULbus registers for this module */ + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) { + dev_err(dev, "MODULbus registers not found\n"); + ret = -ENODEV; + goto out_free_mod; + } + + mod->regs = ioremap(res->start, resource_size(res)); + if (!mod->regs) { + dev_err(dev, "MODULbus registers not ioremap\n"); + ret = -ENOMEM; + goto out_free_mod; + } + + ttl_setup_device(mod); + + /* Initialize the GPIO data structures */ + gpio = &mod->gpio; + gpio->dev = &pdev->dev; + gpio->label = pdev->name; + gpio->get = ttl_get_value; + gpio->set = ttl_set_value; + gpio->owner = THIS_MODULE; + + /* request dynamic allocation */ + gpio->base = -1; + gpio->ngpio = 20; + + ret = gpiochip_add(gpio); + if (ret) { + dev_err(dev, "unable to add GPIO chip\n"); + goto out_iounmap_regs; + } + + dev_info(&pdev->dev, "module %d: registered GPIO device\n", + pdata->modno); + return 0; + +out_iounmap_regs: + iounmap(mod->regs); +out_free_mod: + kfree(mod); +out_return: + return ret; +} + +static int __devexit ttl_remove(struct platform_device *pdev) +{ + struct ttl_module *mod = platform_get_drvdata(pdev); + struct device *dev = &pdev->dev; + int ret; + + ret = gpiochip_remove(&mod->gpio); + if (ret) { + dev_err(dev, "unable to remove GPIO chip\n"); + return ret; + } + + iounmap(mod->regs); + kfree(mod); + return 0; +} + +static struct platform_driver ttl_driver = { + .driver = { + .name = DRV_NAME, + .owner = THIS_MODULE, + }, + .probe = ttl_probe, + .remove = __devexit_p(ttl_remove), +}; + +static int __init ttl_init(void) +{ + return platform_driver_register(&ttl_driver); +} + +static void __exit ttl_exit(void) +{ + platform_driver_unregister(&ttl_driver); +} + +MODULE_AUTHOR("Ira W. Snyder "); +MODULE_DESCRIPTION("Janz MODULbus VMOD-TTL Driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:janz-ttl"); + +module_init(ttl_init); +module_exit(ttl_exit);