ad525x_dpot: add support for SPI parts

Split the bus logic out into separate files so that we can handle I2C and
SPI busses independently.  The new SPI bus logic brings in support for a
lot more parts:

	AD5160, AD5161, AD5162, AD5165, AD5200, AD5201, AD5203,
	AD5204, AD5206, AD5207, AD5231, AD5232, AD5233, AD5235,
	AD5260, AD5262, AD5263, AD5290, AD5291, AD5292, AD5293,
	AD7376, AD8400, AD8402, AD8403, ADN2850

[randy.dunlap@oracle.com: fix ad525X_dpot build]
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 172 insertions, 0 deletions

diff --git a/drivers/misc/ad525x_dpot-spi.c b/drivers/misc/ad525x_dpot-spi.c
new file mode 100644
index 000000000000..b8c6df9c8437
--- /dev/null
+++ b/drivers/misc/ad525x_dpot-spi.c
@@ -0,0 +1,172 @@
+/*
+ * Driver for the Analog Devices digital potentiometers (SPI bus)
+ *
+ * Copyright (C) 2010 Michael Hennerich, Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/spi/spi.h>
+#include <linux/module.h>
+
+#include "ad525x_dpot.h"
+
+static const struct ad_dpot_id ad_dpot_spi_devlist[] = {
+        {.name = "ad5160", .devid = AD5160_ID},
+        {.name = "ad5161", .devid = AD5161_ID},
+        {.name = "ad5162", .devid = AD5162_ID},
+        {.name = "ad5165", .devid = AD5165_ID},
+        {.name = "ad5200", .devid = AD5200_ID},
+        {.name = "ad5201", .devid = AD5201_ID},
+        {.name = "ad5203", .devid = AD5203_ID},
+        {.name = "ad5204", .devid = AD5204_ID},
+        {.name = "ad5206", .devid = AD5206_ID},
+        {.name = "ad5207", .devid = AD5207_ID},
+        {.name = "ad5231", .devid = AD5231_ID},
+        {.name = "ad5232", .devid = AD5232_ID},
+        {.name = "ad5233", .devid = AD5233_ID},
+        {.name = "ad5235", .devid = AD5235_ID},
+        {.name = "ad5260", .devid = AD5260_ID},
+        {.name = "ad5262", .devid = AD5262_ID},
+        {.name = "ad5263", .devid = AD5263_ID},
+        {.name = "ad5290", .devid = AD5290_ID},
+        {.name = "ad5291", .devid = AD5291_ID},
+        {.name = "ad5292", .devid = AD5292_ID},
+        {.name = "ad5293", .devid = AD5293_ID},
+        {.name = "ad7376", .devid = AD7376_ID},
+        {.name = "ad8400", .devid = AD8400_ID},
+        {.name = "ad8402", .devid = AD8402_ID},
+        {.name = "ad8403", .devid = AD8403_ID},
+        {.name = "adn2850", .devid = ADN2850_ID},
+        {}
+};
+
+/* ------------------------------------------------------------------------- */
+
+/* SPI bus functions */
+static int write8(void *client, u8 val)
+{
+        u8 data = val;
+        return spi_write(client, &data, 1);
+}
+
+static int write16(void *client, u8 reg, u8 val)
+{
+        u8 data[2] = {reg, val};
+        return spi_write(client, data, 1);
+}
+
+static int write24(void *client, u8 reg, u16 val)
+{
+        u8 data[3] = {reg, val >> 8, val};
+        return spi_write(client, data, 1);
+}
+
+static int read8(void *client)
+{
+        int ret;
+        u8 data;
+        ret = spi_read(client, &data, 1);
+        if (ret < 0)
+                return ret;
+
+        return data;
+}
+
+static int read16(void *client, u8 reg)
+{
+        int ret;
+        u8 buf_rx[2];
+
+        write16(client, reg, 0);
+        ret = spi_read(client, buf_rx, 2);
+        if (ret < 0)
+                return ret;
+
+        return (buf_rx[0] << 8) |  buf_rx[1];
+}
+
+static int read24(void *client, u8 reg)
+{
+        int ret;
+        u8 buf_rx[3];
+
+        write24(client, reg, 0);
+        ret = spi_read(client, buf_rx, 3);
+        if (ret < 0)
+                return ret;
+
+        return (buf_rx[1] << 8) |  buf_rx[2];
+}
+
+static const struct ad_dpot_bus_ops bops = {
+        .read_d8        = read8,
+        .read_r8d8      = read16,
+        .read_r8d16     = read24,
+        .write_d8       = write8,
+        .write_r8d8     = write16,
+        .write_r8d16    = write24,
+};
+
+static const struct ad_dpot_id *dpot_match_id(const struct ad_dpot_id *id,
+                                                char *name)
+{
+        while (id->name && id->name[0]) {
+                if (strcmp(name, id->name) == 0)
+                        return id;
+                id++;
+        }
+        return NULL;
+}
+
+static int __devinit ad_dpot_spi_probe(struct spi_device *spi)
+{
+        char *name = spi->dev.platform_data;
+        const struct ad_dpot_id *dpot_id;
+
+        struct ad_dpot_bus_data bdata = {
+                .client = spi,
+                .bops = &bops,
+        };
+
+        dpot_id = dpot_match_id(ad_dpot_spi_devlist, name);
+
+        if (dpot_id == NULL) {
+                dev_err(&spi->dev, "%s not in supported device list", name);
+                return -ENODEV;
+        }
+
+        return ad_dpot_probe(&spi->dev, &bdata, dpot_id);
+}
+
+static int __devexit ad_dpot_spi_remove(struct spi_device *spi)
+{
+        return ad_dpot_remove(&spi->dev);
+}
+
+static struct spi_driver ad_dpot_spi_driver = {
+        .driver = {
+                .name   = "ad_dpot",
+                .bus    = &spi_bus_type,
+                .owner  = THIS_MODULE,
+        },
+        .probe          = ad_dpot_spi_probe,
+        .remove         = __devexit_p(ad_dpot_spi_remove),
+};
+
+static int __init ad_dpot_spi_init(void)
+{
+        return spi_register_driver(&ad_dpot_spi_driver);
+}
+module_init(ad_dpot_spi_init);
+
+static void __exit ad_dpot_spi_exit(void)
+{
+        spi_unregister_driver(&ad_dpot_spi_driver);
+}
+module_exit(ad_dpot_spi_exit);
+
+MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
+MODULE_DESCRIPTION("digital potentiometer SPI bus driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("spi:ad_dpot");