SPI: tle620x power switch driver
authorBen Dooks <ben@trinity.fluff.org>
Tue, 17 Jul 2007 11:04:10 +0000 (04:04 -0700)
committerLinus Torvalds <torvalds@woody.linux-foundation.org>
Tue, 17 Jul 2007 17:23:05 +0000 (10:23 -0700)
Add support for the Infineon TLE62x0 series of low-side driver chips, such
as the TLE6220 or TLE6230.  These can be viewed as output GPIOs specialized
for power switching applications.  The driver provides a userspace
interface to those GPIOs, and to the switch status they provide.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/spi/Kconfig
drivers/spi/Makefile
drivers/spi/tle62x0.c [new file with mode: 0644]
include/linux/spi/tle62x0.h [new file with mode: 0644]

index 8ce16a0..a49270e 100644 (file)
@@ -198,6 +198,15 @@ config SPI_SPIDEV
          Note that this application programming interface is EXPERIMENTAL
          and hence SUBJECT TO CHANGE WITHOUT NOTICE while it stabilizes.
 
+config SPI_TLE62X0
+       tristate "Infineon TLE62X0 (for power switching)"
+       depends on SPI_MASTER && SYSFS
+       help
+         SPI driver for Infineon TLE62X0 series line driver chips,
+         such as the TLE6220, TLE6230 and TLE6240.  This provides a
+         sysfs interface, with each line presented as a kind of GPIO
+         exposing both switch control and diagnostic feedback.
+
 #
 # Add new SPI protocol masters in alphabetical order above this line
 #
index 8929333..d9bd7f6 100644 (file)
@@ -29,6 +29,7 @@ obj-$(CONFIG_SPI_S3C24XX)             += spi_s3c24xx.o
 # SPI protocol drivers (device/link on bus)
 obj-$(CONFIG_SPI_AT25)         += at25.o
 obj-$(CONFIG_SPI_SPIDEV)       += spidev.o
+obj-$(CONFIG_SPI_TLE62X0)      += tle62x0.o
 #      ... add above this line ...
 
 # SPI slave controller drivers (upstream link)
diff --git a/drivers/spi/tle62x0.c b/drivers/spi/tle62x0.c
new file mode 100644 (file)
index 0000000..6da58ca
--- /dev/null
@@ -0,0 +1,328 @@
+/*
+ * tle62x0.c -- support Infineon TLE62x0 driver chips
+ *
+ * Copyright (c) 2007 Simtec Electronics
+ *     Ben Dooks, <ben@simtec.co.uk>
+ *
+ * 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.
+ */
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+
+#include <linux/spi/spi.h>
+#include <linux/spi/tle62x0.h>
+
+
+#define CMD_READ       0x00
+#define CMD_SET                0xff
+
+#define DIAG_NORMAL    0x03
+#define DIAG_OVERLOAD  0x02
+#define DIAG_OPEN      0x01
+#define DIAG_SHORTGND  0x00
+
+struct tle62x0_state {
+       struct spi_device       *us;
+       struct mutex            lock;
+       unsigned int            nr_gpio;
+       unsigned int            gpio_state;
+
+       unsigned char           tx_buff[4];
+       unsigned char           rx_buff[4];
+};
+
+static int to_gpio_num(struct device_attribute *attr);
+
+static inline int tle62x0_write(struct tle62x0_state *st)
+{
+       unsigned char *buff = st->tx_buff;
+       unsigned int gpio_state = st->gpio_state;
+
+       buff[0] = CMD_SET;
+
+       if (st->nr_gpio == 16) {
+               buff[1] = gpio_state >> 8;
+               buff[2] = gpio_state;
+       } else {
+               buff[1] = gpio_state;
+       }
+
+       dev_dbg(&st->us->dev, "buff %02x,%02x,%02x\n",
+               buff[0], buff[1], buff[2]);
+
+       return spi_write(st->us, buff, (st->nr_gpio == 16) ? 3 : 2);
+}
+
+static inline int tle62x0_read(struct tle62x0_state *st)
+{
+       unsigned char *txbuff = st->tx_buff;
+       struct spi_transfer xfer = {
+               .tx_buf         = txbuff,
+               .rx_buf         = st->rx_buff,
+               .len            = (st->nr_gpio * 2) / 8,
+       };
+       struct spi_message msg;
+
+       txbuff[0] = CMD_READ;
+       txbuff[1] = 0x00;
+       txbuff[2] = 0x00;
+       txbuff[3] = 0x00;
+
+       spi_message_init(&msg);
+       spi_message_add_tail(&xfer, &msg);
+
+       return spi_sync(st->us, &msg);
+}
+
+static unsigned char *decode_fault(unsigned int fault_code)
+{
+       fault_code &= 3;
+
+       switch (fault_code) {
+       case DIAG_NORMAL:
+               return "N";
+       case DIAG_OVERLOAD:
+               return "V";
+       case DIAG_OPEN:
+               return "O";
+       case DIAG_SHORTGND:
+               return "G";
+       }
+
+       return "?";
+}
+
+static ssize_t tle62x0_status_show(struct device *dev,
+               struct device_attribute *attr, char *buf)
+{
+       struct tle62x0_state *st = dev_get_drvdata(dev);
+       char *bp = buf;
+       unsigned char *buff = st->rx_buff;
+       unsigned long fault = 0;
+       int ptr;
+       int ret;
+
+       mutex_lock(&st->lock);
+       ret = tle62x0_read(st);
+
+       dev_dbg(dev, "tle62x0_read() returned %d\n", ret);
+
+       for (ptr = 0; ptr < (st->nr_gpio * 2)/8; ptr += 1) {
+               fault <<= 8;
+               fault  |= ((unsigned long)buff[ptr]);
+
+               dev_dbg(dev, "byte %d is %02x\n", ptr, buff[ptr]);
+       }
+
+       for (ptr = 0; ptr < st->nr_gpio; ptr++) {
+               bp += sprintf(bp, "%s ", decode_fault(fault >> (ptr * 2)));
+       }
+
+       *bp++ = '\n';
+
+       mutex_unlock(&st->lock);
+       return bp - buf;
+}
+
+static DEVICE_ATTR(status_show, S_IRUGO, tle62x0_status_show, NULL);
+
+static ssize_t tle62x0_gpio_show(struct device *dev,
+               struct device_attribute *attr, char *buf)
+{
+       struct tle62x0_state *st = dev_get_drvdata(dev);
+       int gpio_num = to_gpio_num(attr);
+       int value;
+
+       mutex_lock(&st->lock);
+       value = (st->gpio_state >> gpio_num) & 1;
+       mutex_unlock(&st->lock);
+
+       return snprintf(buf, PAGE_SIZE, "%d", value);
+}
+
+static ssize_t tle62x0_gpio_store(struct device *dev,
+               struct device_attribute *attr,
+               const char *buf, size_t len)
+{
+       struct tle62x0_state *st = dev_get_drvdata(dev);
+       int gpio_num = to_gpio_num(attr);
+       unsigned long val;
+       char *endp;
+
+       val = simple_strtoul(buf, &endp, 0);
+       if (buf == endp)
+               return -EINVAL;
+
+       dev_dbg(dev, "setting gpio %d to %ld\n", gpio_num, val);
+
+       mutex_lock(&st->lock);
+
+       if (val)
+               st->gpio_state |= 1 << gpio_num;
+       else
+               st->gpio_state &= ~(1 << gpio_num);
+
+       tle62x0_write(st);
+       mutex_unlock(&st->lock);
+
+       return len;
+}
+
+static DEVICE_ATTR(gpio1, S_IWUSR|S_IRUGO,
+               tle62x0_gpio_show, tle62x0_gpio_store);
+static DEVICE_ATTR(gpio2, S_IWUSR|S_IRUGO,
+               tle62x0_gpio_show, tle62x0_gpio_store);
+static DEVICE_ATTR(gpio3, S_IWUSR|S_IRUGO,
+               tle62x0_gpio_show, tle62x0_gpio_store);
+static DEVICE_ATTR(gpio4, S_IWUSR|S_IRUGO,
+               tle62x0_gpio_show, tle62x0_gpio_store);
+static DEVICE_ATTR(gpio5, S_IWUSR|S_IRUGO,
+               tle62x0_gpio_show, tle62x0_gpio_store);
+static DEVICE_ATTR(gpio6, S_IWUSR|S_IRUGO,
+               tle62x0_gpio_show, tle62x0_gpio_store);
+static DEVICE_ATTR(gpio7, S_IWUSR|S_IRUGO,
+               tle62x0_gpio_show, tle62x0_gpio_store);
+static DEVICE_ATTR(gpio8, S_IWUSR|S_IRUGO,
+               tle62x0_gpio_show, tle62x0_gpio_store);
+static DEVICE_ATTR(gpio9, S_IWUSR|S_IRUGO,
+               tle62x0_gpio_show, tle62x0_gpio_store);
+static DEVICE_ATTR(gpio10, S_IWUSR|S_IRUGO,
+               tle62x0_gpio_show, tle62x0_gpio_store);
+static DEVICE_ATTR(gpio11, S_IWUSR|S_IRUGO,
+               tle62x0_gpio_show, tle62x0_gpio_store);
+static DEVICE_ATTR(gpio12, S_IWUSR|S_IRUGO,
+               tle62x0_gpio_show, tle62x0_gpio_store);
+static DEVICE_ATTR(gpio13, S_IWUSR|S_IRUGO,
+               tle62x0_gpio_show, tle62x0_gpio_store);
+static DEVICE_ATTR(gpio14, S_IWUSR|S_IRUGO,
+               tle62x0_gpio_show, tle62x0_gpio_store);
+static DEVICE_ATTR(gpio15, S_IWUSR|S_IRUGO,
+               tle62x0_gpio_show, tle62x0_gpio_store);
+static DEVICE_ATTR(gpio16, S_IWUSR|S_IRUGO,
+               tle62x0_gpio_show, tle62x0_gpio_store);
+
+static struct device_attribute *gpio_attrs[] = {
+       [0]             = &dev_attr_gpio1,
+       [1]             = &dev_attr_gpio2,
+       [2]             = &dev_attr_gpio3,
+       [3]             = &dev_attr_gpio4,
+       [4]             = &dev_attr_gpio5,
+       [5]             = &dev_attr_gpio6,
+       [6]             = &dev_attr_gpio7,
+       [7]             = &dev_attr_gpio8,
+       [8]             = &dev_attr_gpio9,
+       [9]             = &dev_attr_gpio10,
+       [10]            = &dev_attr_gpio11,
+       [11]            = &dev_attr_gpio12,
+       [12]            = &dev_attr_gpio13,
+       [13]            = &dev_attr_gpio14,
+       [14]            = &dev_attr_gpio15,
+       [15]            = &dev_attr_gpio16
+};
+
+static int to_gpio_num(struct device_attribute *attr)
+{
+       int ptr;
+
+       for (ptr = 0; ptr < ARRAY_SIZE(gpio_attrs); ptr++) {
+               if (gpio_attrs[ptr] == attr)
+                       return ptr;
+       }
+
+       return -1;
+}
+
+static int __devinit tle62x0_probe(struct spi_device *spi)
+{
+       struct tle62x0_state *st;
+       struct tle62x0_pdata *pdata;
+       int ptr;
+       int ret;
+
+       pdata = spi->dev.platform_data;
+       if (pdata == NULL) {
+               dev_err(&spi->dev, "no device data specified\n");
+               return -EINVAL;
+       }
+
+       st = kzalloc(sizeof(struct tle62x0_state), GFP_KERNEL);
+       if (st == NULL) {
+               dev_err(&spi->dev, "no memory for device state\n");
+               return -ENOMEM;
+       }
+
+       st->us = spi;
+       st->nr_gpio = pdata->gpio_count;
+       st->gpio_state = pdata->init_state;
+
+       mutex_init(&st->lock);
+
+       ret = device_create_file(&spi->dev, &dev_attr_status_show);
+       if (ret) {
+               dev_err(&spi->dev, "cannot create status attribute\n");
+               goto err_status;
+       }
+
+       for (ptr = 0; ptr < pdata->gpio_count; ptr++) {
+               ret = device_create_file(&spi->dev, gpio_attrs[ptr]);
+               if (ret) {
+                       dev_err(&spi->dev, "cannot create gpio attribute\n");
+                       goto err_gpios;
+               }
+       }
+
+       /* tle62x0_write(st); */
+       spi_set_drvdata(spi, st);
+       return 0;
+
+ err_gpios:
+       for (; ptr > 0; ptr--)
+               device_remove_file(&spi->dev, gpio_attrs[ptr]);
+
+       device_remove_file(&spi->dev, &dev_attr_status_show);
+
+ err_status:
+       kfree(st);
+       return ret;
+}
+
+static int __devexit tle62x0_remove(struct spi_device *spi)
+{
+       struct tle62x0_state *st = spi_get_drvdata(spi);
+       int ptr;
+
+       for (ptr = 0; ptr < st->nr_gpio; ptr++)
+               device_remove_file(&spi->dev, gpio_attrs[ptr]);
+
+       kfree(st);
+       return 0;
+}
+
+static struct spi_driver tle62x0_driver = {
+       .driver = {
+               .name   = "tle62x0",
+               .owner  = THIS_MODULE,
+       },
+       .probe          = tle62x0_probe,
+       .remove         = __devexit_p(tle62x0_remove),
+};
+
+static __init int tle62x0_init(void)
+{
+       return spi_register_driver(&tle62x0_driver);
+}
+
+static __exit void tle62x0_exit(void)
+{
+       spi_unregister_driver(&tle62x0_driver);
+}
+
+module_init(tle62x0_init);
+module_exit(tle62x0_exit);
+
+MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
+MODULE_DESCRIPTION("TLE62x0 SPI driver");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/spi/tle62x0.h b/include/linux/spi/tle62x0.h
new file mode 100644 (file)
index 0000000..60b5918
--- /dev/null
@@ -0,0 +1,24 @@
+/*
+ * tle62x0.h - platform glue to Infineon TLE62x0 driver chips
+ *
+ * Copyright 2007 Simtec Electronics
+ *     Ben Dooks <ben@simtec.co.uk>
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+*/
+
+struct tle62x0_pdata {
+       unsigned int            init_state;
+       unsigned int            gpio_count;
+};