gpio: add MC33880 driver

A GPIO driver for the Freescale MC33880 High/Low side switch Signed-off-by: Richard Röjfors <richard.rojfors.ext@mocean-labs.com> Cc: David Brownell <david-b@pacbell.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

gpio: add MC33880 driver
A GPIO driver for the Freescale MC33880 High/Low side switch Signed-off-by: Richard Röjfors <richard.rojfors.ext@mocean-labs.com> Cc: David Brownell <david-b@pacbell.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Richard Röjfors · Linus Torvalds
1 parent a4177ee7f1
Showing 4 changed files with 214 additions and 0 deletions Side-by-side Diff
drivers/gpio/Kconfig
drivers/gpio/Makefile
drivers/gpio/mc33880.c
include/linux/spi/mc33880.h
@@ -195,5 +195,12 @@
 	  SPI driver for Microchip MCP23S08 I/O expander.  This provides
 	  a GPIO interface supporting inputs and outputs.
  
+config GPIO_MC33880
+	tristate "Freescale MC33880 high-side/low-side switch"
+	depends on SPI_MASTER
+	help
+	  SPI driver for Freescale MC33880 high-side/low-side switch.
+	  This provides GPIO interface supporting inputs and outputs.
+
 endif
@@ -6,6 +6,7 @@
  
 obj-$(CONFIG_GPIO_MAX7301)	+= max7301.o
 obj-$(CONFIG_GPIO_MAX732X)	+= max732x.o
+obj-$(CONFIG_GPIO_MC33880)	+= mc33880.o
 obj-$(CONFIG_GPIO_MCP23S08)	+= mcp23s08.o
 obj-$(CONFIG_GPIO_PCA953X)	+= pca953x.o
 obj-$(CONFIG_GPIO_PCF857X)	+= pcf857x.o
+/*
+ * mc33880.c MC33880 high-side/low-side switch GPIO driver
+ * Copyright (c) 2009 Intel Corporation
+ *
+ * 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.
+ *
+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+/* Supports:
+ * Freescale MC33880 high-side/low-side switch
+ */
+
+#include <linux/init.h>
+#include <linux/mutex.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/mc33880.h>
+#include <linux/gpio.h>
+
+#define DRIVER_NAME "mc33880"
+
+/*
+ * Pin configurations, see MAX7301 datasheet page 6
+ */
+#define PIN_CONFIG_MASK 0x03
+#define PIN_CONFIG_IN_PULLUP 0x03
+#define PIN_CONFIG_IN_WO_PULLUP 0x02
+#define PIN_CONFIG_OUT 0x01
+
+#define PIN_NUMBER 8
+
+
+/*
+ * Some registers must be read back to modify.
+ * To save time we cache them here in memory
+ */
+struct mc33880 {
+	struct mutex	lock;	/* protect from simultanous accesses */
+	u8		port_config;
+	struct gpio_chip chip;
+	struct spi_device *spi;
+};
+
+static int mc33880_write_config(struct mc33880 *mc)
+{
+	return spi_write(mc->spi, &mc->port_config, sizeof(mc->port_config));
+}
+
+
+static int __mc33880_set(struct mc33880 *mc, unsigned offset, int value)
+{
+	if (value)
+		mc->port_config |= 1 << offset;
+	else
+		mc->port_config &= ~(1 << offset);
+
+	return mc33880_write_config(mc);
+}
+
+
+static void mc33880_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+	struct mc33880 *mc = container_of(chip, struct mc33880, chip);
+
+	mutex_lock(&mc->lock);
+
+	__mc33880_set(mc, offset, value);
+
+	mutex_unlock(&mc->lock);
+}
+
+static int __devinit mc33880_probe(struct spi_device *spi)
+{
+	struct mc33880 *mc;
+	struct mc33880_platform_data *pdata;
+	int ret;
+
+	pdata = spi->dev.platform_data;
+	if (!pdata || !pdata->base) {
+		dev_dbg(&spi->dev, "incorrect or missing platform data\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * bits_per_word cannot be configured in platform data
+	 */
+	spi->bits_per_word = 8;
+
+	ret = spi_setup(spi);
+	if (ret < 0)
+		return ret;
+
+	mc = kzalloc(sizeof(struct mc33880), GFP_KERNEL);
+	if (!mc)
+		return -ENOMEM;
+
+	mutex_init(&mc->lock);
+
+	dev_set_drvdata(&spi->dev, mc);
+
+	mc->spi = spi;
+
+	mc->chip.label = DRIVER_NAME,
+	mc->chip.set = mc33880_set;
+	mc->chip.base = pdata->base;
+	mc->chip.ngpio = PIN_NUMBER;
+	mc->chip.can_sleep = 1;
+	mc->chip.dev = &spi->dev;
+	mc->chip.owner = THIS_MODULE;
+
+	mc->port_config = 0x00;
+	/* write twice, because during initialisation the first setting
+	 * is just for testing SPI communication, and the second is the
+	 * "real" configuration
+	 */
+	ret = mc33880_write_config(mc);
+	mc->port_config = 0x00;
+	if (!ret)
+		ret = mc33880_write_config(mc);
+
+	if (ret) {
+		printk(KERN_ERR "Failed writing to " DRIVER_NAME ": %d\n", ret);
+		goto exit_destroy;
+	}
+
+	ret = gpiochip_add(&mc->chip);
+	if (ret)
+		goto exit_destroy;
+
+	return ret;
+
+exit_destroy:
+	dev_set_drvdata(&spi->dev, NULL);
+	mutex_destroy(&mc->lock);
+	kfree(mc);
+	return ret;
+}
+
+static int mc33880_remove(struct spi_device *spi)
+{
+	struct mc33880 *mc;
+	int ret;
+
+	mc = dev_get_drvdata(&spi->dev);
+	if (mc == NULL)
+		return -ENODEV;
+
+	dev_set_drvdata(&spi->dev, NULL);
+
+	ret = gpiochip_remove(&mc->chip);
+	if (!ret) {
+		mutex_destroy(&mc->lock);
+		kfree(mc);
+	} else
+		dev_err(&spi->dev, "Failed to remove the GPIO controller: %d\n",
+			ret);
+
+	return ret;
+}
+
+static struct spi_driver mc33880_driver = {
+	.driver = {
+		.name		= DRIVER_NAME,
+		.owner		= THIS_MODULE,
+	},
+	.probe		= mc33880_probe,
+	.remove		= __devexit_p(mc33880_remove),
+};
+
+static int __init mc33880_init(void)
+{
+	return spi_register_driver(&mc33880_driver);
+}
+/* register after spi postcore initcall and before
+ * subsys initcalls that may rely on these GPIOs
+ */
+subsys_initcall(mc33880_init);
+
+static void __exit mc33880_exit(void)
+{
+	spi_unregister_driver(&mc33880_driver);
+}
+module_exit(mc33880_exit);
+
+MODULE_AUTHOR("Mocean Laboratories <info@mocean-labs.com>");
+MODULE_LICENSE("GPL v2");
+#ifndef LINUX_SPI_MC33880_H
+#define LINUX_SPI_MC33880_H
+
+struct mc33880_platform_data {
+	/* number assigned to the first GPIO */
+	unsigned	base;
+};
+
+#endif
...	...	@@ -195,5 +195,12 @@
195	195	SPI driver for Microchip MCP23S08 I/O expander. This provides
196	196	a GPIO interface supporting inputs and outputs.
197	197
	198	+config GPIO_MC33880
	199	+ tristate "Freescale MC33880 high-side/low-side switch"
	200	+ depends on SPI_MASTER
	201	+ help
	202	+ SPI driver for Freescale MC33880 high-side/low-side switch.
	203	+ This provides GPIO interface supporting inputs and outputs.
	204	+
198	205	endif
...	...	@@ -6,6 +6,7 @@
6	6
7	7	obj-$(CONFIG_GPIO_MAX7301) += max7301.o
8	8	obj-$(CONFIG_GPIO_MAX732X) += max732x.o
	9	+obj-$(CONFIG_GPIO_MC33880) += mc33880.o
9	10	obj-$(CONFIG_GPIO_MCP23S08) += mcp23s08.o
10	11	obj-$(CONFIG_GPIO_PCA953X) += pca953x.o
11	12	obj-$(CONFIG_GPIO_PCF857X) += pcf857x.o
	1	+/*
	2	+ * mc33880.c MC33880 high-side/low-side switch GPIO driver
	3	+ * Copyright (c) 2009 Intel Corporation
	4	+ *
	5	+ * This program is free software; you can redistribute it and/or modify
	6	+ * it under the terms of the GNU General Public License version 2 as
	7	+ * published by the Free Software Foundation.
	8	+ *
	9	+ * This program is distributed in the hope that it will be useful,
	10	+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	+ * GNU General Public License for more details.
	13	+ *
	14	+ * You should have received a copy of the GNU General Public License
	15	+ * along with this program; if not, write to the Free Software
	16	+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	17	+ */
	18	+
	19	+/* Supports:
	20	+ * Freescale MC33880 high-side/low-side switch
	21	+ */
	22	+
	23	+#include <linux/init.h>
	24	+#include <linux/mutex.h>
	25	+#include <linux/spi/spi.h>
	26	+#include <linux/spi/mc33880.h>
	27	+#include <linux/gpio.h>
	28	+
	29	+#define DRIVER_NAME "mc33880"
	30	+
	31	+/*
	32	+ * Pin configurations, see MAX7301 datasheet page 6
	33	+ */
	34	+#define PIN_CONFIG_MASK 0x03
	35	+#define PIN_CONFIG_IN_PULLUP 0x03
	36	+#define PIN_CONFIG_IN_WO_PULLUP 0x02
	37	+#define PIN_CONFIG_OUT 0x01
	38	+
	39	+#define PIN_NUMBER 8
	40	+
	41	+
	42	+/*
	43	+ * Some registers must be read back to modify.
	44	+ * To save time we cache them here in memory
	45	+ */
	46	+struct mc33880 {
	47	+ struct mutex lock; /* protect from simultanous accesses */
	48	+ u8 port_config;
	49	+ struct gpio_chip chip;
	50	+ struct spi_device *spi;
	51	+};
	52	+
	53	+static int mc33880_write_config(struct mc33880 *mc)
	54	+{
	55	+ return spi_write(mc->spi, &mc->port_config, sizeof(mc->port_config));
	56	+}
	57	+
	58	+
	59	+static int __mc33880_set(struct mc33880 *mc, unsigned offset, int value)
	60	+{
	61	+ if (value)
	62	+ mc->port_config \|= 1 << offset;
	63	+ else
	64	+ mc->port_config &= ~(1 << offset);
	65	+
	66	+ return mc33880_write_config(mc);
	67	+}
	68	+
	69	+
	70	+static void mc33880_set(struct gpio_chip *chip, unsigned offset, int value)
	71	+{
	72	+ struct mc33880 *mc = container_of(chip, struct mc33880, chip);
	73	+
	74	+ mutex_lock(&mc->lock);
	75	+
	76	+ __mc33880_set(mc, offset, value);
	77	+
	78	+ mutex_unlock(&mc->lock);
	79	+}
	80	+
	81	+static int __devinit mc33880_probe(struct spi_device *spi)
	82	+{
	83	+ struct mc33880 *mc;
	84	+ struct mc33880_platform_data *pdata;
	85	+ int ret;
	86	+
	87	+ pdata = spi->dev.platform_data;
	88	+ if (!pdata \|\| !pdata->base) {
	89	+ dev_dbg(&spi->dev, "incorrect or missing platform data\n");
	90	+ return -EINVAL;
	91	+ }
	92	+
	93	+ /*
	94	+ * bits_per_word cannot be configured in platform data
	95	+ */
	96	+ spi->bits_per_word = 8;
	97	+
	98	+ ret = spi_setup(spi);
	99	+ if (ret < 0)
	100	+ return ret;
	101	+
	102	+ mc = kzalloc(sizeof(struct mc33880), GFP_KERNEL);
	103	+ if (!mc)
	104	+ return -ENOMEM;
	105	+
	106	+ mutex_init(&mc->lock);
	107	+
	108	+ dev_set_drvdata(&spi->dev, mc);
	109	+
	110	+ mc->spi = spi;
	111	+
	112	+ mc->chip.label = DRIVER_NAME,
	113	+ mc->chip.set = mc33880_set;
	114	+ mc->chip.base = pdata->base;
	115	+ mc->chip.ngpio = PIN_NUMBER;
	116	+ mc->chip.can_sleep = 1;
	117	+ mc->chip.dev = &spi->dev;
	118	+ mc->chip.owner = THIS_MODULE;
	119	+
	120	+ mc->port_config = 0x00;
	121	+ /* write twice, because during initialisation the first setting
	122	+ * is just for testing SPI communication, and the second is the
	123	+ * "real" configuration
	124	+ */
	125	+ ret = mc33880_write_config(mc);
	126	+ mc->port_config = 0x00;
	127	+ if (!ret)
	128	+ ret = mc33880_write_config(mc);
	129	+
	130	+ if (ret) {
	131	+ printk(KERN_ERR "Failed writing to " DRIVER_NAME ": %d\n", ret);
	132	+ goto exit_destroy;
	133	+ }
	134	+
	135	+ ret = gpiochip_add(&mc->chip);
	136	+ if (ret)
	137	+ goto exit_destroy;
	138	+
	139	+ return ret;
	140	+
	141	+exit_destroy:
	142	+ dev_set_drvdata(&spi->dev, NULL);
	143	+ mutex_destroy(&mc->lock);
	144	+ kfree(mc);
	145	+ return ret;
	146	+}
	147	+
	148	+static int mc33880_remove(struct spi_device *spi)
	149	+{
	150	+ struct mc33880 *mc;
	151	+ int ret;
	152	+
	153	+ mc = dev_get_drvdata(&spi->dev);
	154	+ if (mc == NULL)
	155	+ return -ENODEV;
	156	+
	157	+ dev_set_drvdata(&spi->dev, NULL);
	158	+
	159	+ ret = gpiochip_remove(&mc->chip);
	160	+ if (!ret) {
	161	+ mutex_destroy(&mc->lock);
	162	+ kfree(mc);
	163	+ } else
	164	+ dev_err(&spi->dev, "Failed to remove the GPIO controller: %d\n",
	165	+ ret);
	166	+
	167	+ return ret;
	168	+}
	169	+
	170	+static struct spi_driver mc33880_driver = {
	171	+ .driver = {
	172	+ .name = DRIVER_NAME,
	173	+ .owner = THIS_MODULE,
	174	+ },
	175	+ .probe = mc33880_probe,
	176	+ .remove = __devexit_p(mc33880_remove),
	177	+};
	178	+
	179	+static int __init mc33880_init(void)
	180	+{
	181	+ return spi_register_driver(&mc33880_driver);
	182	+}
	183	+/* register after spi postcore initcall and before
	184	+ * subsys initcalls that may rely on these GPIOs
	185	+ */
	186	+subsys_initcall(mc33880_init);
	187	+
	188	+static void __exit mc33880_exit(void)
	189	+{
	190	+ spi_unregister_driver(&mc33880_driver);
	191	+}
	192	+module_exit(mc33880_exit);
	193	+
	194	+MODULE_AUTHOR("Mocean Laboratories <info@mocean-labs.com>");
	195	+MODULE_LICENSE("GPL v2");
	1	+#ifndef LINUX_SPI_MC33880_H
	2	+#define LINUX_SPI_MC33880_H
	3	+
	4	+struct mc33880_platform_data {
	5	+ /* number assigned to the first GPIO */
	6	+ unsigned base;
	7	+};
	8	+
	9	+#endif