[PATCH] i2c: Add driver for powermac keywest i2c interface

Here is a patch that adds an i2c bus driver for the i2c interface
found in the "KeyWest" and later combo-I/O chips used in powermacs.
The patch is against Linus' current BK tree.

drivers/i2c/Kconfig

@@ -142,6 +142,17 @@ config I2C_ELEKTOR
 	  <file:Documentation/modules.txt>.
 	  The module will be called i2c-elektor.
 
+config I2C_KEYWEST
+	tristate "Powermac Keywest I2C interface"
+	depends on I2C && ALL_PPC
+	help
+	  This supports the use of the I2C interface in the combo-I/O
+	  chip on recent Apple machines.  Say Y if you have such a machine.
+
+	  This driver is also available as a module.  If you want to compile
+	  it as a module, say M here and read Documentation/modules.txt.
+	  The module will be called i2c-keywest.
+
 config ITE_I2C_ALGO
 	tristate "ITE I2C Algorithm"
 	depends on MIPS_ITE8172 && I2C

drivers/i2c/Makefile

@@ -10,6 +10,7 @@ obj-$(CONFIG_I2C_ELV)		+= i2c-elv.o
 obj-$(CONFIG_I2C_VELLEMAN)	+= i2c-velleman.o
 obj-$(CONFIG_I2C_ALGOPCF)	+= i2c-algo-pcf.o
 obj-$(CONFIG_I2C_ELEKTOR)	+= i2c-elektor.o
+obj-$(CONFIG_I2C_KEYWEST)	+= i2c-keywest.o
 obj-$(CONFIG_ITE_I2C_ALGO)	+= i2c-algo-ite.o
 obj-$(CONFIG_ITE_I2C_ADAP)	+= i2c-adap-ite.o
 obj-$(CONFIG_SCx200_I2C)	+= scx200_i2c.o

drivers/i2c/i2c-keywest.h

+#ifndef __I2C_KEYWEST_H__
+#define __I2C_KEYWEST_H__
+
+/* The Tumbler audio equalizer can be really slow sometimes */
+#define POLL_TIMEOUT		(2*HZ)
+
+/* Register indices */
+typedef enum {
+	reg_mode = 0,
+	reg_control,
+	reg_status,
+	reg_isr,
+	reg_ier,
+	reg_addr,
+	reg_subaddr,
+	reg_data
+} reg_t;
+
+
+/* Mode register */
+#define KW_I2C_MODE_100KHZ	0x00
+#define KW_I2C_MODE_50KHZ	0x01
+#define KW_I2C_MODE_25KHZ	0x02
+#define KW_I2C_MODE_DUMB	0x00
+#define KW_I2C_MODE_STANDARD	0x04
+#define KW_I2C_MODE_STANDARDSUB	0x08
+#define KW_I2C_MODE_COMBINED	0x0C
+#define KW_I2C_MODE_MODE_MASK	0x0C
+#define KW_I2C_MODE_CHAN_MASK	0xF0
+
+/* Control register */
+#define KW_I2C_CTL_AAK		0x01
+#define KW_I2C_CTL_XADDR	0x02
+#define KW_I2C_CTL_STOP		0x04
+#define KW_I2C_CTL_START	0x08
+
+/* Status register */
+#define KW_I2C_STAT_BUSY	0x01
+#define KW_I2C_STAT_LAST_AAK	0x02
+#define KW_I2C_STAT_LAST_RW	0x04
+#define KW_I2C_STAT_SDA		0x08
+#define KW_I2C_STAT_SCL		0x10
+
+/* IER & ISR registers */
+#define KW_I2C_IRQ_DATA		0x01
+#define KW_I2C_IRQ_ADDR		0x02
+#define KW_I2C_IRQ_STOP		0x04
+#define KW_I2C_IRQ_START	0x08
+#define KW_I2C_IRQ_MASK		0x0F
+
+/* Physical interface */
+struct keywest_iface
+{
+	unsigned long		base;
+	unsigned		bsteps;
+	int			irq;
+	struct semaphore	sem;
+	spinlock_t		lock;
+	struct keywest_chan*	channels;
+	unsigned		chan_count;
+	u8			cur_mode;
+	char			read_write;
+	u8*			data;
+	unsigned		datalen;
+	int			state;
+	int			result;
+	int			stopretry;
+	struct timer_list	timeout_timer;
+	struct completion	complete;
+	struct keywest_iface*	next;
+};
+
+enum {
+	state_idle,
+	state_addr,
+	state_read,
+	state_write,
+	state_stop,
+	state_dead
+};
+
+/* Channel on an interface */
+struct keywest_chan
+{
+	struct i2c_adapter	adapter;
+	struct keywest_iface*	iface;
+	unsigned		chan_no;
+};
+
+/* Register access */
+
+static inline u8 __read_reg(struct keywest_iface *iface, reg_t reg)
+{
+	return in_8(((volatile u8 *)iface->base)
+		+ (((unsigned)reg) << iface->bsteps));
+}
+
+static inline void __write_reg(struct keywest_iface *iface, reg_t reg, u8 val)
+{
+	out_8(((volatile u8 *)iface->base)
+		+ (((unsigned)reg) << iface->bsteps), val);
+	(void)__read_reg(iface, reg);
+	udelay(10);
+}
+
+#define write_reg(reg, val)	__write_reg(iface, reg, val) 
+#define read_reg(reg)		__read_reg(iface, reg) 
+
+
+
+#endif /* __I2C_KEYWEST_H__ */