mfd: New AB8500 driver
Add a new driver to support the AB8500 Power Management chip, replacing
the current AB4500. The new driver replaces the old one, instead of an
incremental modification, because this is a substantial overhaul
including:
- Split of the driver into -core and -spi portions, to allow another
interface layer to be added
- Addition of interrupt support
- Switch to MFD core API for handling subdevices
- Simplification of the APIs to remove a redundant block parameter
- Rename of the APIs and macros from ab4500_* to ab8500_*
- Rename of the files from ab4500* to ab8500*
- Change of the driver name from ab4500 to ab8500
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Acked-by: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/mfd/ab8500-spi.c b/drivers/mfd/ab8500-spi.c
new file mode 100644
index 0000000..b81d4f7
--- /dev/null
+++ b/drivers/mfd/ab8500-spi.c
@@ -0,0 +1,133 @@
+/*
+ * Copyright (C) ST-Ericsson SA 2010
+ *
+ * License Terms: GNU General Public License v2
+ * Author: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/spi/spi.h>
+#include <linux/mfd/ab8500.h>
+
+/*
+ * This funtion writes to any AB8500 registers using
+ * SPI protocol & before it writes it packs the data
+ * in the below 24 bit frame format
+ *
+ * *|------------------------------------|
+ * *| 23|22...18|17.......10|9|8|7......0|
+ * *| r/w bank adr data |
+ * * ------------------------------------
+ *
+ * This function shouldn't be called from interrupt
+ * context
+ */
+static int ab8500_spi_write(struct ab8500 *ab8500, u16 addr, u8 data)
+{
+ struct spi_device *spi = container_of(ab8500->dev, struct spi_device,
+ dev);
+ unsigned long spi_data = addr << 10 | data;
+ struct spi_transfer xfer;
+ struct spi_message msg;
+
+ ab8500->tx_buf[0] = spi_data;
+ ab8500->rx_buf[0] = 0;
+
+ xfer.tx_buf = ab8500->tx_buf;
+ xfer.rx_buf = NULL;
+ xfer.len = sizeof(unsigned long);
+
+ spi_message_init(&msg);
+ spi_message_add_tail(&xfer, &msg);
+
+ return spi_sync(spi, &msg);
+}
+
+static int ab8500_spi_read(struct ab8500 *ab8500, u16 addr)
+{
+ struct spi_device *spi = container_of(ab8500->dev, struct spi_device,
+ dev);
+ unsigned long spi_data = 1 << 23 | addr << 10;
+ struct spi_transfer xfer;
+ struct spi_message msg;
+ int ret;
+
+ ab8500->tx_buf[0] = spi_data;
+ ab8500->rx_buf[0] = 0;
+
+ xfer.tx_buf = ab8500->tx_buf;
+ xfer.rx_buf = ab8500->rx_buf;
+ xfer.len = sizeof(unsigned long);
+
+ spi_message_init(&msg);
+ spi_message_add_tail(&xfer, &msg);
+
+ ret = spi_sync(spi, &msg);
+ if (!ret)
+ ret = ab8500->rx_buf[0];
+
+ return ret;
+}
+
+static int __devinit ab8500_spi_probe(struct spi_device *spi)
+{
+ struct ab8500 *ab8500;
+ int ret;
+
+ ab8500 = kzalloc(sizeof *ab8500, GFP_KERNEL);
+ if (!ab8500)
+ return -ENOMEM;
+
+ ab8500->dev = &spi->dev;
+ ab8500->irq = spi->irq;
+
+ ab8500->read = ab8500_spi_read;
+ ab8500->write = ab8500_spi_write;
+
+ spi_set_drvdata(spi, ab8500);
+
+ ret = ab8500_init(ab8500);
+ if (ret)
+ kfree(ab8500);
+
+ return ret;
+}
+
+static int __devexit ab8500_spi_remove(struct spi_device *spi)
+{
+ struct ab8500 *ab8500 = spi_get_drvdata(spi);
+
+ ab8500_exit(ab8500);
+ kfree(ab8500);
+
+ return 0;
+}
+
+static struct spi_driver ab8500_spi_driver = {
+ .driver = {
+ .name = "ab8500",
+ .owner = THIS_MODULE,
+ },
+ .probe = ab8500_spi_probe,
+ .remove = __devexit_p(ab8500_spi_remove)
+};
+
+static int __init ab8500_spi_init(void)
+{
+ return spi_register_driver(&ab8500_spi_driver);
+}
+subsys_initcall(ab8500_spi_init);
+
+static void __exit ab8500_spi_exit(void)
+{
+ spi_unregister_driver(&ab8500_spi_driver);
+}
+module_exit(ab8500_spi_exit);
+
+MODULE_AUTHOR("Srinidhi KASAGAR <srinidhi.kasagar@stericsson.com");
+MODULE_DESCRIPTION("AB8500 SPI");
+MODULE_LICENSE("GPL v2");