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authorLinus Torvalds <torvalds@linux-foundation.org>2011-07-22 21:50:57 (GMT)
committerLinus Torvalds <torvalds@linux-foundation.org>2011-07-22 21:50:57 (GMT)
commitc7c8518498e82591d7784452f5674c3aeb4d079c (patch)
tree790ff7e6b6741daf32ec686b9a302b957b07c0f4 /drivers/gpio/gpio-mc33880.c
parentece236ce2fad9c27a6fd2530f899289025194bce (diff)
parent591567a5ea25852f20b7ef2953f6f72020121199 (diff)
downloadlinux-fsl-qoriq-c7c8518498e82591d7784452f5674c3aeb4d079c.tar.xz
Merge branch 'gpio/next' of git://git.secretlab.ca/git/linux-2.6
* 'gpio/next' of git://git.secretlab.ca/git/linux-2.6: (61 commits) gpio/mxc/mxs: fix build error introduced by the irq_gc_ack() renaming mcp23s08: add i2c support mcp23s08: isolate spi specific parts mcp23s08: get rid of setup/teardown callbacks gpio/tegra: dt: add binding for gpio polarity mcp23s08: remove unused work queue gpio/da9052: remove a redundant assignment for gpio->da9052 gpio/mxc: add device tree probe support ARM: mxc: use ARCH_NR_GPIOS to define gpio number gpio/mxc: get rid of the uses of cpu_is_mx() gpio/mxc: add missing initialization of basic_mmio_gpio shadow variables gpio: Move mpc5200 gpio driver to drivers/gpio GPIO: DA9052 GPIO module v3 gpio/tegra: Use engineering names in DT compatible property of/gpio: Add new method for getting gpios under different property names gpio/dt: Refine GPIO device tree binding gpio/ml-ioh: fix off-by-one for displaying variable i in dev_err gpio/pca953x: Deprecate meaningless device-tree bindings gpio/pca953x: Remove dynamic platform data pointer gpio/pca953x: Fix IRQ support. ...
Diffstat (limited to 'drivers/gpio/gpio-mc33880.c')
-rw-r--r--drivers/gpio/gpio-mc33880.c197
1 files changed, 197 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-mc33880.c b/drivers/gpio/gpio-mc33880.c
new file mode 100644
index 0000000..b3b4652
--- /dev/null
+++ b/drivers/gpio/gpio-mc33880.c
@@ -0,0 +1,197 @@
+/*
+ * 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>
+#include <linux/slab.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 simultaneous 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 __devexit 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");
+