1 files changed, 136 insertions, 0 deletions
diff --git a/include/linux/eeprom.h b/include/linux/eeprom.h
new file mode 100644
index 00000000000..38afd9da1df
--- /dev/null
+++ b/include/linux/eeprom.h
@@ -0,0 +1,136 @@
+/* credit winbond-840.c
+ */
+#include <asm/io.h>
+struct eeprom_ops {
+	void	(*set_cs)(void *ee);
+	void	(*clear_cs)(void *ee);
+};
+
+#define EEPOL_EEDI	0x01
+#define EEPOL_EEDO	0x02
+#define EEPOL_EECLK	0x04
+#define EEPOL_EESEL	0x08
+
+struct eeprom {
+	void *dev;
+	struct eeprom_ops *ops;
+
+	void __iomem *	addr;
+
+	unsigned	ee_addr_bits;
+
+	unsigned	eesel;
+	unsigned	eeclk;
+	unsigned	eedo;
+	unsigned	eedi;
+	unsigned	polarity;
+	unsigned	ee_state;
+
+	spinlock_t	*lock;
+	u32		*cache;
+};
+
+
+u8   eeprom_readb(struct eeprom *ee, unsigned address);
+void eeprom_read(struct eeprom *ee, unsigned address, u8 *bytes,
+		unsigned count);
+void eeprom_writeb(struct eeprom *ee, unsigned address, u8 data);
+void eeprom_write(struct eeprom *ee, unsigned address, u8 *bytes,
+		unsigned count);
+
+/* The EEPROM commands include the alway-set leading bit. */
+enum EEPROM_Cmds {
+        EE_WriteCmd=(5 << 6), EE_ReadCmd=(6 << 6), EE_EraseCmd=(7 << 6),
+};
+
+void setup_ee_mem_bitbanger(struct eeprom *ee, void __iomem *memaddr, int eesel_bit, int eeclk_bit, int eedo_bit, int eedi_bit, unsigned polarity)
+{
+	ee->addr = memaddr;
+	ee->eesel = 1 << eesel_bit;
+	ee->eeclk = 1 << eeclk_bit;
+	ee->eedo = 1 << eedo_bit;
+	ee->eedi = 1 << eedi_bit;
+
+	ee->polarity = polarity;
+
+	*ee->cache = readl(ee->addr);
+}
+
+/* foo. put this in a .c file */
+static inline void eeprom_update(struct eeprom *ee, u32 mask, int pol)
+{
+	unsigned long flags;
+	u32 data;
+
+	spin_lock_irqsave(ee->lock, flags);
+	data = *ee->cache;
+
+	data &= ~mask;
+	if (pol)
+		data |= mask;
+
+	*ee->cache = data;
+//printk("update: %08x\n", data);
+	writel(data, ee->addr);
+	spin_unlock_irqrestore(ee->lock, flags);
+}
+
+void eeprom_clk_lo(struct eeprom *ee)
+{
+	int pol = !!(ee->polarity & EEPOL_EECLK);
+
+	eeprom_update(ee, ee->eeclk, pol);
+	udelay(2);
+}
+
+void eeprom_clk_hi(struct eeprom *ee)
+{
+	int pol = !!(ee->polarity & EEPOL_EECLK);
+
+	eeprom_update(ee, ee->eeclk, !pol);
+	udelay(2);
+}
+
+void eeprom_send_addr(struct eeprom *ee, unsigned address)
+{
+	int pol = !!(ee->polarity & EEPOL_EEDI);
+	unsigned i;
+	address |= 6 << 6;
+
+        /* Shift the read command bits out. */
+        for (i=0; i<11; i++) {
+		eeprom_update(ee, ee->eedi, ((address >> 10) & 1) ^ pol);
+		address <<= 1;
+		eeprom_clk_hi(ee);
+		eeprom_clk_lo(ee);
+        }
+	eeprom_update(ee, ee->eedi, pol);
+}
+
+u16   eeprom_readw(struct eeprom *ee, unsigned address)
+{
+	unsigned i;
+	u16	res = 0;
+
+	eeprom_clk_lo(ee);
+	eeprom_update(ee, ee->eesel, 1 ^ !!(ee->polarity & EEPOL_EESEL));
+	eeprom_send_addr(ee, address);
+
+	for (i=0; i<16; i++) {
+		u32 data;
+		eeprom_clk_hi(ee);
+		res <<= 1;
+		data = readl(ee->addr);
+//printk("eeprom_readw: %08x\n", data);
+		res |= !!(data & ee->eedo) ^ !!(ee->polarity & EEPOL_EEDO);
+		eeprom_clk_lo(ee);
+	}
+	eeprom_update(ee, ee->eesel, 0 ^ !!(ee->polarity & EEPOL_EESEL));
+
+	return res;
+}
+
+
+void eeprom_writeb(struct eeprom *ee, unsigned address, u8 data)
+{
+}