mfd: Add WM831x SPI support

Implement support for controlling WM831x and WM832x devices using SPI.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

drivers/mfd/Kconfig

@@ -329,6 +329,17 @@ config MFD_WM831X_I2C
 	  for accessing the device, additional drivers must be enabled in
 	  order to use the functionality of the device.
 
+config MFD_WM831X_SPI
+	bool "Support Wolfson Microelectronics WM831x/2x PMICs with SPI"
+	select MFD_CORE
+	select MFD_WM831X
+	depends on SPI_MASTER && GENERIC_HARDIRQS
+	help
+	  Support for the Wolfson Microelecronics WM831x and WM832x PMICs
+	  when controlled using SPI.  This driver provides common support
+	  for accessing the device, additional drivers must be enabled in
+	  order to use the functionality of the device.
+
 config MFD_WM8350
 	bool
 	depends on GENERIC_HARDIRQS

drivers/mfd/Makefile

@@ -25,6 +25,7 @@ obj-$(CONFIG_MFD_WM8400)	+= wm8400-core.o
 wm831x-objs			:= wm831x-core.o wm831x-irq.o wm831x-otp.o
 obj-$(CONFIG_MFD_WM831X)	+= wm831x.o
 obj-$(CONFIG_MFD_WM831X_I2C)	+= wm831x-i2c.o
+obj-$(CONFIG_MFD_WM831X_SPI)	+= wm831x-spi.o
 wm8350-objs			:= wm8350-core.o wm8350-regmap.o wm8350-gpio.o
 wm8350-objs			+= wm8350-irq.o
 obj-$(CONFIG_MFD_WM8350)	+= wm8350.o

drivers/mfd/wm831x-spi.c

@@ -0,0 +1,232 @@
+/*
+ * wm831x-spi.c  --  SPI access for Wolfson WM831x PMICs
+ *
+ * Copyright 2009,2010 Wolfson Microelectronics PLC.
+ *
+ * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
+ *
+ *  This program is free software; you can redistribute  it and/or modify it
+ *  under  the terms of  the GNU General  Public License as published by the
+ *  Free Software Foundation;  either version 2 of the  License, or (at your
+ *  option) any later version.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/spi/spi.h>
+
+#include <linux/mfd/wm831x/core.h>
+
+static int wm831x_spi_read_device(struct wm831x *wm831x, unsigned short reg,
+				  int bytes, void *dest)
+{
+	u16 tx_val;
+	u16 *d = dest;
+	int r, ret;
+
+	/* Go register at a time */
+	for (r = reg; r < reg + (bytes / 2); r++) {
+		tx_val = r | 0x8000;
+
+		ret = spi_write_then_read(wm831x->control_data,
+					  (u8 *)&tx_val, 2, (u8 *)d, 2);
+		if (ret != 0)
+			return ret;
+
+		*d = be16_to_cpu(*d);
+
+		d++;
+	}
+
+	return 0;
+}
+
+static int wm831x_spi_write_device(struct wm831x *wm831x, unsigned short reg,
+				   int bytes, void *src)
+{
+	struct spi_device *spi = wm831x->control_data;
+	u16 *s = src;
+	u16 data[2];
+	int ret, r;
+
+	/* Go register at a time */
+	for (r = reg; r < reg + (bytes / 2); r++) {
+		data[0] = r;
+		data[1] = *s++;
+
+		ret = spi_write(spi, (char *)&data, sizeof(data));
+		if (ret != 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int __devinit wm831x_spi_probe(struct spi_device *spi)
+{
+	struct wm831x *wm831x;
+	enum wm831x_parent type;
+
+	/* Currently SPI support for ID tables is unmerged, we're faking it */
+	if (strcmp(spi->modalias, "wm8310") == 0)
+		type = WM8310;
+	else if (strcmp(spi->modalias, "wm8311") == 0)
+		type = WM8311;
+	else if (strcmp(spi->modalias, "wm8312") == 0)
+		type = WM8312;
+	else if (strcmp(spi->modalias, "wm8320") == 0)
+		type = WM8320;
+	else if (strcmp(spi->modalias, "wm8321") == 0)
+		type = WM8321;
+	else if (strcmp(spi->modalias, "wm8325") == 0)
+		type = WM8325;
+	else {
+		dev_err(&spi->dev, "Unknown device type\n");
+		return -EINVAL;
+	}
+
+	wm831x = kzalloc(sizeof(struct wm831x), GFP_KERNEL);
+	if (wm831x == NULL)
+		return -ENOMEM;
+
+	spi->bits_per_word = 16;
+	spi->mode = SPI_MODE_0;
+
+	dev_set_drvdata(&spi->dev, wm831x);
+	wm831x->dev = &spi->dev;
+	wm831x->control_data = spi;
+	wm831x->read_dev = wm831x_spi_read_device;
+	wm831x->write_dev = wm831x_spi_write_device;
+
+	return wm831x_device_init(wm831x, type, spi->irq);
+}
+
+static int __devexit wm831x_spi_remove(struct spi_device *spi)
+{
+	struct wm831x *wm831x = dev_get_drvdata(&spi->dev);
+
+	wm831x_device_exit(wm831x);
+
+	return 0;
+}
+
+static int wm831x_spi_suspend(struct spi_device *spi, pm_message_t m)
+{
+	struct wm831x *wm831x = dev_get_drvdata(&spi->dev);
+
+	return wm831x_device_suspend(wm831x);
+}
+
+static struct spi_driver wm8310_spi_driver = {
+	.driver = {
+		.name	= "wm8310",
+		.bus	= &spi_bus_type,
+		.owner	= THIS_MODULE,
+	},
+	.probe		= wm831x_spi_probe,
+	.remove		= __devexit_p(wm831x_spi_remove),
+	.suspend	= wm831x_spi_suspend,
+};
+
+static struct spi_driver wm8311_spi_driver = {
+	.driver = {
+		.name	= "wm8311",
+		.bus	= &spi_bus_type,
+		.owner	= THIS_MODULE,
+	},
+	.probe		= wm831x_spi_probe,
+	.remove		= __devexit_p(wm831x_spi_remove),
+	.suspend	= wm831x_spi_suspend,
+};
+
+static struct spi_driver wm8312_spi_driver = {
+	.driver = {
+		.name	= "wm8312",
+		.bus	= &spi_bus_type,
+		.owner	= THIS_MODULE,
+	},
+	.probe		= wm831x_spi_probe,
+	.remove		= __devexit_p(wm831x_spi_remove),
+	.suspend	= wm831x_spi_suspend,
+};
+
+static struct spi_driver wm8320_spi_driver = {
+	.driver = {
+		.name	= "wm8320",
+		.bus	= &spi_bus_type,
+		.owner	= THIS_MODULE,
+	},
+	.probe		= wm831x_spi_probe,
+	.remove		= __devexit_p(wm831x_spi_remove),
+	.suspend	= wm831x_spi_suspend,
+};
+
+static struct spi_driver wm8321_spi_driver = {
+	.driver = {
+		.name	= "wm8321",
+		.bus	= &spi_bus_type,
+		.owner	= THIS_MODULE,
+	},
+	.probe		= wm831x_spi_probe,
+	.remove		= __devexit_p(wm831x_spi_remove),
+	.suspend	= wm831x_spi_suspend,
+};
+
+static struct spi_driver wm8325_spi_driver = {
+	.driver = {
+		.name	= "wm8325",
+		.bus	= &spi_bus_type,
+		.owner	= THIS_MODULE,
+	},
+	.probe		= wm831x_spi_probe,
+	.remove		= __devexit_p(wm831x_spi_remove),
+	.suspend	= wm831x_spi_suspend,
+};
+
+static int __init wm831x_spi_init(void)
+{
+	int ret;
+
+	ret = spi_register_driver(&wm8310_spi_driver);
+	if (ret != 0)
+		pr_err("Failed to register WM8310 SPI driver: %d\n", ret);
+
+	ret = spi_register_driver(&wm8311_spi_driver);
+	if (ret != 0)
+		pr_err("Failed to register WM8311 SPI driver: %d\n", ret);
+
+	ret = spi_register_driver(&wm8312_spi_driver);
+	if (ret != 0)
+		pr_err("Failed to register WM8312 SPI driver: %d\n", ret);
+
+	ret = spi_register_driver(&wm8320_spi_driver);
+	if (ret != 0)
+		pr_err("Failed to register WM8320 SPI driver: %d\n", ret);
+
+	ret = spi_register_driver(&wm8321_spi_driver);
+	if (ret != 0)
+		pr_err("Failed to register WM8321 SPI driver: %d\n", ret);
+
+	ret = spi_register_driver(&wm8325_spi_driver);
+	if (ret != 0)
+		pr_err("Failed to register WM8325 SPI driver: %d\n", ret);
+
+	return 0;
+}
+subsys_initcall(wm831x_spi_init);
+
+static void __exit wm831x_spi_exit(void)
+{
+	spi_unregister_driver(&wm8325_spi_driver);
+	spi_unregister_driver(&wm8321_spi_driver);
+	spi_unregister_driver(&wm8320_spi_driver);
+	spi_unregister_driver(&wm8312_spi_driver);
+	spi_unregister_driver(&wm8311_spi_driver);
+	spi_unregister_driver(&wm8310_spi_driver);
+}
+module_exit(wm831x_spi_exit);
+
+MODULE_DESCRIPTION("SPI support for WM831x/2x AudioPlus PMICs");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Mark Brown");