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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 <iws@ovro.caltech.edu> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
This commit is contained in:
Ira W. Snyder
Samuel Ortiz
parent
631eb22784
commit
800e69fbd2
@ -325,4 +325,14 @@ config GPIO_UCB1400
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To compile this driver as a module, choose M here: the
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module will be called ucb1400_gpio.
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comment "MODULbus GPIO expanders:"
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config GPIO_JANZ_TTL
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tristate "Janz VMOD-TTL Digital IO Module"
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depends on MFD_JANZ_CMODIO
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help
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This enables support for the Janz VMOD-TTL Digital IO module.
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This driver provides support for driving the pins in output
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mode only. Input mode is not supported.
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endif
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@ -29,3 +29,4 @@ obj-$(CONFIG_GPIO_WM8350) += wm8350-gpiolib.o
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obj-$(CONFIG_GPIO_WM8994) += wm8994-gpio.o
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obj-$(CONFIG_GPIO_SCH) += sch_gpio.o
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obj-$(CONFIG_GPIO_RDC321X) += rdc321x-gpio.o
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obj-$(CONFIG_GPIO_JANZ_TTL) += janz-ttl.o
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258
drivers/gpio/janz-ttl.c
Normal file
258
drivers/gpio/janz-ttl.c
Normal file
@ -0,0 +1,258 @@
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/*
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* Janz MODULbus VMOD-TTL GPIO Driver
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*
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* Copyright (c) 2010 Ira W. Snyder <iws@ovro.caltech.edu>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/delay.h>
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#include <linux/platform_device.h>
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#include <linux/io.h>
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#include <linux/gpio.h>
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#include <linux/slab.h>
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#include <linux/mfd/janz.h>
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#define DRV_NAME "janz-ttl"
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#define PORTA_DIRECTION 0x23
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#define PORTB_DIRECTION 0x2B
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#define PORTC_DIRECTION 0x06
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#define PORTA_IOCTL 0x24
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#define PORTB_IOCTL 0x2C
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#define PORTC_IOCTL 0x07
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#define MASTER_INT_CTL 0x00
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#define MASTER_CONF_CTL 0x01
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#define CONF_PAE (1 << 2)
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#define CONF_PBE (1 << 7)
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#define CONF_PCE (1 << 4)
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struct ttl_control_regs {
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__be16 portc;
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__be16 portb;
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__be16 porta;
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__be16 control;
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};
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struct ttl_module {
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struct gpio_chip gpio;
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/* base address of registers */
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struct ttl_control_regs __iomem *regs;
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u8 portc_shadow;
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u8 portb_shadow;
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u8 porta_shadow;
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spinlock_t lock;
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};
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static int ttl_get_value(struct gpio_chip *gpio, unsigned offset)
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{
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struct ttl_module *mod = dev_get_drvdata(gpio->dev);
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u8 *shadow;
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int ret;
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if (offset < 8) {
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shadow = &mod->porta_shadow;
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} else if (offset < 16) {
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shadow = &mod->portb_shadow;
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offset -= 8;
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} else {
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shadow = &mod->portc_shadow;
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offset -= 16;
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}
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spin_lock(&mod->lock);
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ret = *shadow & (1 << offset);
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spin_unlock(&mod->lock);
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return ret;
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}
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static void ttl_set_value(struct gpio_chip *gpio, unsigned offset, int value)
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{
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struct ttl_module *mod = dev_get_drvdata(gpio->dev);
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void __iomem *port;
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u8 *shadow;
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if (offset < 8) {
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port = &mod->regs->porta;
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shadow = &mod->porta_shadow;
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} else if (offset < 16) {
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port = &mod->regs->portb;
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shadow = &mod->portb_shadow;
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offset -= 8;
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} else {
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port = &mod->regs->portc;
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shadow = &mod->portc_shadow;
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offset -= 16;
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}
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spin_lock(&mod->lock);
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if (value)
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*shadow |= (1 << offset);
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else
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*shadow &= ~(1 << offset);
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iowrite16be(*shadow, port);
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spin_unlock(&mod->lock);
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}
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static void __devinit ttl_write_reg(struct ttl_module *mod, u8 reg, u16 val)
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{
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iowrite16be(reg, &mod->regs->control);
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iowrite16be(val, &mod->regs->control);
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}
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static void __devinit ttl_setup_device(struct ttl_module *mod)
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{
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/* reset the device to a known state */
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iowrite16be(0x0000, &mod->regs->control);
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iowrite16be(0x0001, &mod->regs->control);
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iowrite16be(0x0000, &mod->regs->control);
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/* put all ports in open-drain mode */
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ttl_write_reg(mod, PORTA_IOCTL, 0x00ff);
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ttl_write_reg(mod, PORTB_IOCTL, 0x00ff);
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ttl_write_reg(mod, PORTC_IOCTL, 0x000f);
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/* set all ports as outputs */
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ttl_write_reg(mod, PORTA_DIRECTION, 0x0000);
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ttl_write_reg(mod, PORTB_DIRECTION, 0x0000);
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ttl_write_reg(mod, PORTC_DIRECTION, 0x0000);
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/* set all ports to drive zeroes */
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iowrite16be(0x0000, &mod->regs->porta);
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iowrite16be(0x0000, &mod->regs->portb);
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iowrite16be(0x0000, &mod->regs->portc);
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/* enable all ports */
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ttl_write_reg(mod, MASTER_CONF_CTL, CONF_PAE | CONF_PBE | CONF_PCE);
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}
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static int __devinit ttl_probe(struct platform_device *pdev)
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{
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struct janz_platform_data *pdata;
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struct device *dev = &pdev->dev;
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struct ttl_module *mod;
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struct gpio_chip *gpio;
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struct resource *res;
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int ret;
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pdata = pdev->dev.platform_data;
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if (!pdata) {
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dev_err(dev, "no platform data\n");
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ret = -ENXIO;
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goto out_return;
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}
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mod = kzalloc(sizeof(*mod), GFP_KERNEL);
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if (!mod) {
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dev_err(dev, "unable to allocate private data\n");
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ret = -ENOMEM;
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goto out_return;
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}
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platform_set_drvdata(pdev, mod);
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spin_lock_init(&mod->lock);
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/* get access to the MODULbus registers for this module */
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!res) {
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dev_err(dev, "MODULbus registers not found\n");
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ret = -ENODEV;
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goto out_free_mod;
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}
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mod->regs = ioremap(res->start, resource_size(res));
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if (!mod->regs) {
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dev_err(dev, "MODULbus registers not ioremap\n");
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ret = -ENOMEM;
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goto out_free_mod;
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}
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ttl_setup_device(mod);
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/* Initialize the GPIO data structures */
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gpio = &mod->gpio;
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gpio->dev = &pdev->dev;
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gpio->label = pdev->name;
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gpio->get = ttl_get_value;
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gpio->set = ttl_set_value;
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gpio->owner = THIS_MODULE;
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/* request dynamic allocation */
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gpio->base = -1;
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gpio->ngpio = 20;
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ret = gpiochip_add(gpio);
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if (ret) {
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dev_err(dev, "unable to add GPIO chip\n");
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goto out_iounmap_regs;
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}
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dev_info(&pdev->dev, "module %d: registered GPIO device\n",
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pdata->modno);
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return 0;
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out_iounmap_regs:
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iounmap(mod->regs);
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out_free_mod:
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kfree(mod);
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out_return:
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return ret;
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}
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static int __devexit ttl_remove(struct platform_device *pdev)
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{
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struct ttl_module *mod = platform_get_drvdata(pdev);
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struct device *dev = &pdev->dev;
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int ret;
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ret = gpiochip_remove(&mod->gpio);
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if (ret) {
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dev_err(dev, "unable to remove GPIO chip\n");
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return ret;
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}
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iounmap(mod->regs);
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kfree(mod);
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return 0;
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}
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static struct platform_driver ttl_driver = {
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.driver = {
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.name = DRV_NAME,
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.owner = THIS_MODULE,
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},
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.probe = ttl_probe,
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.remove = __devexit_p(ttl_remove),
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};
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static int __init ttl_init(void)
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{
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return platform_driver_register(&ttl_driver);
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}
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static void __exit ttl_exit(void)
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{
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platform_driver_unregister(&ttl_driver);
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}
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MODULE_AUTHOR("Ira W. Snyder <iws@ovro.caltech.edu>");
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MODULE_DESCRIPTION("Janz MODULbus VMOD-TTL Driver");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:janz-ttl");
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module_init(ttl_init);
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module_exit(ttl_exit);
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