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>

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>
Ira W. Snyder · Samuel Ortiz
1 parent 631eb22784
Showing 3 changed files with 269 additions and 0 deletions Side-by-side Diff
drivers/gpio/Kconfig
drivers/gpio/Makefile
drivers/gpio/janz-ttl.c
@@ -325,5 +325,15 @@
 	  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
@@ -29,4 +29,5 @@
 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
+/*
+ * Janz MODULbus VMOD-TTL GPIO Driver
+ *
+ * Copyright (c) 2010 Ira W. Snyder <iws@ovro.caltech.edu>
+ *
+ * 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 <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/gpio.h>
+#include <linux/slab.h>
+
+#include <linux/mfd/janz.h>
+
+#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 <iws@ovro.caltech.edu>");
+MODULE_DESCRIPTION("Janz MODULbus VMOD-TTL Driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:janz-ttl");
+
+module_init(ttl_init);
+module_exit(ttl_exit);
...	...	@@ -325,5 +325,15 @@
325	325	To compile this driver as a module, choose M here: the
326	326	module will be called ucb1400_gpio.
327	327
	328	+comment "MODULbus GPIO expanders:"
	329	+
	330	+config GPIO_JANZ_TTL
	331	+ tristate "Janz VMOD-TTL Digital IO Module"
	332	+ depends on MFD_JANZ_CMODIO
	333	+ help
	334	+ This enables support for the Janz VMOD-TTL Digital IO module.
	335	+ This driver provides support for driving the pins in output
	336	+ mode only. Input mode is not supported.
	337	+
328	338	endif
...	...	@@ -29,4 +29,5 @@
29	29	obj-$(CONFIG_GPIO_WM8994) += wm8994-gpio.o
30	30	obj-$(CONFIG_GPIO_SCH) += sch_gpio.o
31	31	obj-$(CONFIG_GPIO_RDC321X) += rdc321x-gpio.o
	32	+obj-$(CONFIG_GPIO_JANZ_TTL) += janz-ttl.o
	1	+/*
	2	+ * Janz MODULbus VMOD-TTL GPIO Driver
	3	+ *
	4	+ * Copyright (c) 2010 Ira W. Snyder <iws@ovro.caltech.edu>
	5	+ *
	6	+ * This program is free software; you can redistribute it and/or modify it
	7	+ * under the terms of the GNU General Public License as published by the
	8	+ * Free Software Foundation; either version 2 of the License, or (at your
	9	+ * option) any later version.
	10	+ */
	11	+
	12	+#include <linux/kernel.h>
	13	+#include <linux/module.h>
	14	+#include <linux/init.h>
	15	+#include <linux/interrupt.h>
	16	+#include <linux/delay.h>
	17	+#include <linux/platform_device.h>
	18	+#include <linux/io.h>
	19	+#include <linux/gpio.h>
	20	+#include <linux/slab.h>
	21	+
	22	+#include <linux/mfd/janz.h>
	23	+
	24	+#define DRV_NAME "janz-ttl"
	25	+
	26	+#define PORTA_DIRECTION 0x23
	27	+#define PORTB_DIRECTION 0x2B
	28	+#define PORTC_DIRECTION 0x06
	29	+#define PORTA_IOCTL 0x24
	30	+#define PORTB_IOCTL 0x2C
	31	+#define PORTC_IOCTL 0x07
	32	+
	33	+#define MASTER_INT_CTL 0x00
	34	+#define MASTER_CONF_CTL 0x01
	35	+
	36	+#define CONF_PAE (1 << 2)
	37	+#define CONF_PBE (1 << 7)
	38	+#define CONF_PCE (1 << 4)
	39	+
	40	+struct ttl_control_regs {
	41	+ __be16 portc;
	42	+ __be16 portb;
	43	+ __be16 porta;
	44	+ __be16 control;
	45	+};
	46	+
	47	+struct ttl_module {
	48	+ struct gpio_chip gpio;
	49	+
	50	+ /* base address of registers */
	51	+ struct ttl_control_regs __iomem *regs;
	52	+
	53	+ u8 portc_shadow;
	54	+ u8 portb_shadow;
	55	+ u8 porta_shadow;
	56	+
	57	+ spinlock_t lock;
	58	+};
	59	+
	60	+static int ttl_get_value(struct gpio_chip *gpio, unsigned offset)
	61	+{
	62	+ struct ttl_module *mod = dev_get_drvdata(gpio->dev);
	63	+ u8 *shadow;
	64	+ int ret;
	65	+
	66	+ if (offset < 8) {
	67	+ shadow = &mod->porta_shadow;
	68	+ } else if (offset < 16) {
	69	+ shadow = &mod->portb_shadow;
	70	+ offset -= 8;
	71	+ } else {
	72	+ shadow = &mod->portc_shadow;
	73	+ offset -= 16;
	74	+ }
	75	+
	76	+ spin_lock(&mod->lock);
	77	+ ret = *shadow & (1 << offset);
	78	+ spin_unlock(&mod->lock);
	79	+ return ret;
	80	+}
	81	+
	82	+static void ttl_set_value(struct gpio_chip *gpio, unsigned offset, int value)
	83	+{
	84	+ struct ttl_module *mod = dev_get_drvdata(gpio->dev);
	85	+ void __iomem *port;
	86	+ u8 *shadow;
	87	+
	88	+ if (offset < 8) {
	89	+ port = &mod->regs->porta;
	90	+ shadow = &mod->porta_shadow;
	91	+ } else if (offset < 16) {
	92	+ port = &mod->regs->portb;
	93	+ shadow = &mod->portb_shadow;
	94	+ offset -= 8;
	95	+ } else {
	96	+ port = &mod->regs->portc;
	97	+ shadow = &mod->portc_shadow;
	98	+ offset -= 16;
	99	+ }
	100	+
	101	+ spin_lock(&mod->lock);
	102	+ if (value)
	103	+ *shadow \|= (1 << offset);
	104	+ else
	105	+ *shadow &= ~(1 << offset);
	106	+
	107	+ iowrite16be(*shadow, port);
	108	+ spin_unlock(&mod->lock);
	109	+}
	110	+
	111	+static void __devinit ttl_write_reg(struct ttl_module *mod, u8 reg, u16 val)
	112	+{
	113	+ iowrite16be(reg, &mod->regs->control);
	114	+ iowrite16be(val, &mod->regs->control);
	115	+}
	116	+
	117	+static void __devinit ttl_setup_device(struct ttl_module *mod)
	118	+{
	119	+ /* reset the device to a known state */
	120	+ iowrite16be(0x0000, &mod->regs->control);
	121	+ iowrite16be(0x0001, &mod->regs->control);
	122	+ iowrite16be(0x0000, &mod->regs->control);
	123	+
	124	+ /* put all ports in open-drain mode */
	125	+ ttl_write_reg(mod, PORTA_IOCTL, 0x00ff);
	126	+ ttl_write_reg(mod, PORTB_IOCTL, 0x00ff);
	127	+ ttl_write_reg(mod, PORTC_IOCTL, 0x000f);
	128	+
	129	+ /* set all ports as outputs */
	130	+ ttl_write_reg(mod, PORTA_DIRECTION, 0x0000);
	131	+ ttl_write_reg(mod, PORTB_DIRECTION, 0x0000);
	132	+ ttl_write_reg(mod, PORTC_DIRECTION, 0x0000);
	133	+
	134	+ /* set all ports to drive zeroes */
	135	+ iowrite16be(0x0000, &mod->regs->porta);
	136	+ iowrite16be(0x0000, &mod->regs->portb);
	137	+ iowrite16be(0x0000, &mod->regs->portc);
	138	+
	139	+ /* enable all ports */
	140	+ ttl_write_reg(mod, MASTER_CONF_CTL, CONF_PAE \| CONF_PBE \| CONF_PCE);
	141	+}
	142	+
	143	+static int __devinit ttl_probe(struct platform_device *pdev)
	144	+{
	145	+ struct janz_platform_data *pdata;
	146	+ struct device *dev = &pdev->dev;
	147	+ struct ttl_module *mod;
	148	+ struct gpio_chip *gpio;
	149	+ struct resource *res;
	150	+ int ret;
	151	+
	152	+ pdata = pdev->dev.platform_data;
	153	+ if (!pdata) {
	154	+ dev_err(dev, "no platform data\n");
	155	+ ret = -ENXIO;
	156	+ goto out_return;
	157	+ }
	158	+
	159	+ mod = kzalloc(sizeof(*mod), GFP_KERNEL);
	160	+ if (!mod) {
	161	+ dev_err(dev, "unable to allocate private data\n");
	162	+ ret = -ENOMEM;
	163	+ goto out_return;
	164	+ }
	165	+
	166	+ platform_set_drvdata(pdev, mod);
	167	+ spin_lock_init(&mod->lock);
	168	+
	169	+ /* get access to the MODULbus registers for this module */
	170	+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	171	+ if (!res) {
	172	+ dev_err(dev, "MODULbus registers not found\n");
	173	+ ret = -ENODEV;
	174	+ goto out_free_mod;
	175	+ }
	176	+
	177	+ mod->regs = ioremap(res->start, resource_size(res));
	178	+ if (!mod->regs) {
	179	+ dev_err(dev, "MODULbus registers not ioremap\n");
	180	+ ret = -ENOMEM;
	181	+ goto out_free_mod;
	182	+ }
	183	+
	184	+ ttl_setup_device(mod);
	185	+
	186	+ /* Initialize the GPIO data structures */
	187	+ gpio = &mod->gpio;
	188	+ gpio->dev = &pdev->dev;
	189	+ gpio->label = pdev->name;
	190	+ gpio->get = ttl_get_value;
	191	+ gpio->set = ttl_set_value;
	192	+ gpio->owner = THIS_MODULE;
	193	+
	194	+ /* request dynamic allocation */
	195	+ gpio->base = -1;
	196	+ gpio->ngpio = 20;
	197	+
	198	+ ret = gpiochip_add(gpio);
	199	+ if (ret) {
	200	+ dev_err(dev, "unable to add GPIO chip\n");
	201	+ goto out_iounmap_regs;
	202	+ }
	203	+
	204	+ dev_info(&pdev->dev, "module %d: registered GPIO device\n",
	205	+ pdata->modno);
	206	+ return 0;
	207	+
	208	+out_iounmap_regs:
	209	+ iounmap(mod->regs);
	210	+out_free_mod:
	211	+ kfree(mod);
	212	+out_return:
	213	+ return ret;
	214	+}
	215	+
	216	+static int __devexit ttl_remove(struct platform_device *pdev)
	217	+{
	218	+ struct ttl_module *mod = platform_get_drvdata(pdev);
	219	+ struct device *dev = &pdev->dev;
	220	+ int ret;
	221	+
	222	+ ret = gpiochip_remove(&mod->gpio);
	223	+ if (ret) {
	224	+ dev_err(dev, "unable to remove GPIO chip\n");
	225	+ return ret;
	226	+ }
	227	+
	228	+ iounmap(mod->regs);
	229	+ kfree(mod);
	230	+ return 0;
	231	+}
	232	+
	233	+static struct platform_driver ttl_driver = {
	234	+ .driver = {
	235	+ .name = DRV_NAME,
	236	+ .owner = THIS_MODULE,
	237	+ },
	238	+ .probe = ttl_probe,
	239	+ .remove = __devexit_p(ttl_remove),
	240	+};
	241	+
	242	+static int __init ttl_init(void)
	243	+{
	244	+ return platform_driver_register(&ttl_driver);
	245	+}
	246	+
	247	+static void __exit ttl_exit(void)
	248	+{
	249	+ platform_driver_unregister(&ttl_driver);
	250	+}
	251	+
	252	+MODULE_AUTHOR("Ira W. Snyder <iws@ovro.caltech.edu>");
	253	+MODULE_DESCRIPTION("Janz MODULbus VMOD-TTL Driver");
	254	+MODULE_LICENSE("GPL");
	255	+MODULE_ALIAS("platform:janz-ttl");
	256	+
	257	+module_init(ttl_init);
	258	+module_exit(ttl_exit);