Merge tag 'v2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

[mv-sheeva.git] / drivers / staging / iio / addac / adt7316-spi.c

diff --git a/drivers/staging/iio/addac/adt7316-spi.c b/drivers/staging/iio/addac/adt7316-spi.c
new file mode 100644 (file)
index 0000000..369d4d0
--- /dev/null
+++ b/drivers/staging/iio/addac/adt7316-spi.c
@@ -0,0 +1,180 @@
+/*
+ * API bus driver for ADT7316/7/8 ADT7516/7/9 digital temperature
+ * sensor, ADC and DAC
+ *
+ * Copyright 2010 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/spi/spi.h>
+
+#include "adt7316.h"
+
+#define ADT7316_SPI_MAX_FREQ_HZ                5000000
+#define ADT7316_SPI_CMD_READ           0x91
+#define ADT7316_SPI_CMD_WRITE          0x90
+
+/*
+ * adt7316 register access by SPI
+ */
+
+static int adt7316_spi_multi_read(void *client, u8 reg, u8 count, u8 *data)
+{
+       struct spi_device *spi_dev = client;
+       u8 cmd[2];
+       int ret = 0;
+
+       if (count > ADT7316_REG_MAX_ADDR)
+               count = ADT7316_REG_MAX_ADDR;
+
+       cmd[0] = ADT7316_SPI_CMD_WRITE;
+       cmd[1] = reg;
+
+       ret = spi_write(spi_dev, cmd, 2);
+       if (ret < 0) {
+               dev_err(&spi_dev->dev, "SPI fail to select reg\n");
+               return ret;
+       }
+
+       cmd[0] = ADT7316_SPI_CMD_READ;
+
+       ret = spi_write_then_read(spi_dev, cmd, 1, data, count);
+       if (ret < 0) {
+               dev_err(&spi_dev->dev, "SPI read data error\n");
+               return ret;
+       }
+
+       return 0;
+}
+
+static int adt7316_spi_multi_write(void *client, u8 reg, u8 count, u8 *data)
+{
+       struct spi_device *spi_dev = client;
+       u8 buf[ADT7316_REG_MAX_ADDR + 2];
+       int i, ret = 0;
+
+       if (count > ADT7316_REG_MAX_ADDR)
+               count = ADT7316_REG_MAX_ADDR;
+
+       buf[0] = ADT7316_SPI_CMD_WRITE;
+       buf[1] = reg;
+       for (i = 0; i < count; i++)
+               buf[i + 2] = data[i];
+
+       ret = spi_write(spi_dev, buf, count + 2);
+       if (ret < 0) {
+               dev_err(&spi_dev->dev, "SPI write error\n");
+               return ret;
+       }
+
+       return ret;
+}
+
+static int adt7316_spi_read(void *client, u8 reg, u8 *data)
+{
+       return adt7316_spi_multi_read(client, reg, 1, data);
+}
+
+static int adt7316_spi_write(void *client, u8 reg, u8 val)
+{
+       return adt7316_spi_multi_write(client, reg, 1, &val);
+}
+
+/*
+ * device probe and remove
+ */
+
+static int __devinit adt7316_spi_probe(struct spi_device *spi_dev)
+{
+       struct adt7316_bus bus = {
+               .client = spi_dev,
+               .irq = spi_dev->irq,
+               .irq_flags = IRQF_TRIGGER_LOW,
+               .read = adt7316_spi_read,
+               .write = adt7316_spi_write,
+               .multi_read = adt7316_spi_multi_read,
+               .multi_write = adt7316_spi_multi_write,
+       };
+
+       /* don't exceed max specified SPI CLK frequency */
+       if (spi_dev->max_speed_hz > ADT7316_SPI_MAX_FREQ_HZ) {
+               dev_err(&spi_dev->dev, "SPI CLK %d Hz?\n",
+                       spi_dev->max_speed_hz);
+               return -EINVAL;
+       }
+
+       /* switch from default I2C protocol to SPI protocol */
+       adt7316_spi_write(spi_dev, 0, 0);
+       adt7316_spi_write(spi_dev, 0, 0);
+       adt7316_spi_write(spi_dev, 0, 0);
+
+       return adt7316_probe(&spi_dev->dev, &bus, spi_dev->modalias);
+}
+
+static int __devexit adt7316_spi_remove(struct spi_device *spi_dev)
+{
+       return adt7316_remove(&spi_dev->dev);
+}
+
+static const struct spi_device_id adt7316_spi_id[] = {
+       { "adt7316", 0 },
+       { "adt7317", 0 },
+       { "adt7318", 0 },
+       { "adt7516", 0 },
+       { "adt7517", 0 },
+       { "adt7519", 0 },
+       { }
+};
+
+MODULE_DEVICE_TABLE(spi, adt7316_spi_id);
+
+#ifdef CONFIG_PM
+static int adt7316_spi_suspend(struct spi_device *spi_dev, pm_message_t message)
+{
+       return adt7316_disable(&spi_dev->dev);
+}
+
+static int adt7316_spi_resume(struct spi_device *spi_dev)
+{
+       return adt7316_enable(&spi_dev->dev);
+}
+#else
+# define adt7316_spi_suspend NULL
+# define adt7316_spi_resume  NULL
+#endif
+
+static struct spi_driver adt7316_driver = {
+       .driver = {
+               .name = "adt7316",
+               .bus = &spi_bus_type,
+               .owner = THIS_MODULE,
+       },
+       .probe = adt7316_spi_probe,
+       .remove = __devexit_p(adt7316_spi_remove),
+       .suspend = adt7316_spi_suspend,
+       .resume = adt7316_spi_resume,
+       .id_table = adt7316_spi_id,
+};
+
+static __init int adt7316_spi_init(void)
+{
+       return spi_register_driver(&adt7316_driver);
+}
+
+static __exit void adt7316_spi_exit(void)
+{
+       spi_unregister_driver(&adt7316_driver);
+}
+
+MODULE_AUTHOR("Sonic Zhang <sonic.zhang@analog.com>");
+MODULE_DESCRIPTION("SPI bus driver for Analog Devices ADT7316/7/8 and"
+                       "ADT7516/7/9 digital temperature sensor, ADC and DAC");
+MODULE_LICENSE("GPL v2");
+
+module_init(adt7316_spi_init);
+module_exit(adt7316_spi_exit);