i2c: sh: Add support I2C for Renesas SH

This supports I2C of Renesas SH.
I tested on SH7724.

Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
CC: Heiko Schocher <hs@denx.de>

1 files changed, 292 insertions, 0 deletions

diff --git a/drivers/i2c/sh_i2c.c b/drivers/i2c/sh_i2c.c
new file mode 100644
index 000000000..fd8cb9285
--- /dev/null
+++ b/drivers/i2c/sh_i2c.c
@@ -0,0 +1,292 @@
+/*
+ * Copyright (C) 2011 Renesas Solutions Corp.
+ * Copyright (C) 2011 Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <asm/io.h>
+
+/* Every register is 32bit aligned, but only 8bits in size */
+#define ureg(name) u8 name; u8 __pad_##name##0; u16 __pad_##name##1;
+struct sh_i2c {
+	ureg(icdr);
+	ureg(iccr);
+	ureg(icsr);
+	ureg(icic);
+	ureg(iccl);
+	ureg(icch);
+};
+#undef ureg
+
+static struct sh_i2c *base;
+
+/* ICCR */
+#define SH_I2C_ICCR_ICE		(1 << 7)
+#define SH_I2C_ICCR_RACK	(1 << 6)
+#define SH_I2C_ICCR_RTS		(1 << 4)
+#define SH_I2C_ICCR_BUSY	(1 << 2)
+#define SH_I2C_ICCR_SCP		(1 << 0)
+
+/* ICSR / ICIC */
+#define SH_IC_BUSY	(1 << 3)
+#define SH_IC_TACK	(1 << 2)
+#define SH_IC_WAIT	(1 << 1)
+#define SH_IC_DTE	(1 << 0)
+
+static u8 iccl, icch;
+
+#define IRQ_WAIT 1000
+
+static void irq_wait(struct sh_i2c *base)
+{
+	int i;
+	u8 status;
+
+	for (i = 0 ; i < IRQ_WAIT ; i++) {
+		status = readb(&base->icsr);
+		if (SH_IC_WAIT & status)
+			break;
+
+		udelay(10);
+	}
+
+	writeb(status & ~SH_IC_WAIT, &base->icsr);
+}
+
+static void irq_dte(struct sh_i2c *base)
+{
+	int i;
+
+	for (i = 0 ; i < IRQ_WAIT ; i++) {
+		if (SH_IC_DTE & readb(&base->icsr))
+			break;
+		udelay(10);
+	}
+}
+
+static void irq_busy(struct sh_i2c *base)
+{
+	int i;
+
+	for (i = 0 ; i < IRQ_WAIT ; i++) {
+		if (!(SH_IC_BUSY & readb(&base->icsr)))
+			break;
+		udelay(10);
+	}
+}
+
+static void i2c_set_addr(struct sh_i2c *base, u8 id, u8 reg, int stop)
+{
+	writeb(readb(&base->iccr) & ~SH_I2C_ICCR_ICE, &base->iccr);
+	writeb(readb(&base->iccr) | SH_I2C_ICCR_ICE, &base->iccr);
+
+	writeb(iccl, &base->iccl);
+	writeb(icch, &base->icch);
+	writeb(0, &base->icic);
+
+	writeb((SH_I2C_ICCR_ICE|SH_I2C_ICCR_RTS|SH_I2C_ICCR_BUSY), &base->iccr);
+	irq_dte(base);
+
+	writeb(id << 1, &base->icdr);
+	irq_dte(base);
+
+	writeb(reg, &base->icdr);
+	if (stop)
+		writeb((SH_I2C_ICCR_ICE|SH_I2C_ICCR_RTS), &base->iccr);
+
+	irq_dte(base);
+}
+
+static void i2c_finish(struct sh_i2c *base)
+{
+	writeb(0, &base->icsr);
+	writeb(readb(&base->iccr) & ~SH_I2C_ICCR_ICE, &base->iccr);
+}
+
+static void i2c_raw_write(struct sh_i2c *base, u8 id, u8 reg, u8 val)
+{
+	i2c_set_addr(base, id, reg, 0);
+	udelay(10);
+
+	writeb(val, &base->icdr);
+	irq_dte(base);
+
+	writeb((SH_I2C_ICCR_ICE | SH_I2C_ICCR_RTS), &base->iccr);
+	irq_dte(base);
+	irq_busy(base);
+
+	i2c_finish(base);
+}
+
+static u8 i2c_raw_read(struct sh_i2c *base, u8 id, u8 reg)
+{
+	u8 ret;
+
+	i2c_set_addr(base, id, reg, 1);
+	udelay(100);
+
+	writeb((SH_I2C_ICCR_ICE|SH_I2C_ICCR_RTS|SH_I2C_ICCR_BUSY), &base->iccr);
+	irq_dte(base);
+
+	writeb(id << 1 | 0x01, &base->icdr);
+	irq_dte(base);
+
+	writeb((SH_I2C_ICCR_ICE|SH_I2C_ICCR_SCP), &base->iccr);
+	irq_dte(base);
+
+	ret = readb(&base->icdr);
+
+	writeb((SH_I2C_ICCR_ICE|SH_I2C_ICCR_RACK), &base->iccr);
+	readb(&base->icdr); /* Dummy read */
+	irq_busy(base);
+
+	i2c_finish(base);
+
+	return ret;
+}
+
+#ifdef CONFIG_I2C_MULTI_BUS
+static unsigned int current_bus;
+
+/**
+ * i2c_set_bus_num - change active I2C bus
+ *	@bus: bus index, zero based
+ *	@returns: 0 on success, non-0 on failure
+ */
+int i2c_set_bus_num(unsigned int bus)
+{
+	if ((bus < 0) || (bus >= CONFIG_SYS_MAX_I2C_BUS)) {
+		printf("Bad bus: %d\n", bus);
+		return -1;
+	}
+
+	switch (bus) {
+	case 0:
+		base = (void *)CONFIG_SH_I2C_BASE0;
+		break;
+	case 1:
+		base = (void *)CONFIG_SH_I2C_BASE1;
+		break;
+	default:
+		return -1;
+	}
+	current_bus = bus;
+
+	return 0;
+}
+
+/**
+ * i2c_get_bus_num - returns index of active I2C bus
+ */
+unsigned int i2c_get_bus_num(void)
+{
+	return current_bus;
+}
+#endif
+
+#define SH_I2C_ICCL_CALC(clk, date, t_low, t_high) \
+		((clk / rate) * (t_low / t_low + t_high))
+#define SH_I2C_ICCH_CALC(clk, date, t_low, t_high) \
+		((clk / rate) * (t_high / t_low + t_high))
+
+void i2c_init(int speed, int slaveaddr)
+{
+	int num, denom, tmp;
+
+#ifdef CONFIG_I2C_MULTI_BUS
+	current_bus = 0;
+#endif
+	base = (struct sh_i2c *)CONFIG_SH_I2C_BASE0;
+
+	/*
+	 * Calculate the value for iccl. From the data sheet:
+	 * iccl = (p-clock / transfer-rate) * (L / (L + H))
+	 * where L and H are the SCL low and high ratio.
+	 */
+	num = CONFIG_SH_I2C_CLOCK * CONFIG_SH_I2C_DATA_LOW;
+	denom = speed * (CONFIG_SH_I2C_DATA_HIGH + CONFIG_SH_I2C_DATA_LOW);
+	tmp = num * 10 / denom;
+	if (tmp % 10 >= 5)
+		iccl = (u8)((num/denom) + 1);
+	else
+		iccl = (u8)(num/denom);
+
+	/* Calculate the value for icch. From the data sheet:
+	   icch = (p clock / transfer rate) * (H / (L + H)) */
+	num = CONFIG_SH_I2C_CLOCK * CONFIG_SH_I2C_DATA_HIGH;
+	tmp = num * 10 / denom;
+	if (tmp % 10 >= 5)
+		icch = (u8)((num/denom) + 1);
+	else
+		icch = (u8)(num/denom);
+}
+
+/*
+ * i2c_read: - Read multiple bytes from an i2c device
+ *
+ * The higher level routines take into account that this function is only
+ * called with len < page length of the device (see configuration file)
+ *
+ * @chip:   address of the chip which is to be read
+ * @addr:   i2c data address within the chip
+ * @alen:   length of the i2c data address (1..2 bytes)
+ * @buffer: where to write the data
+ * @len:    how much byte do we want to read
+ * @return: 0 in case of success
+ */
+int i2c_read(u8 chip, u32 addr, int alen, u8 *buffer, int len)
+{
+	int i = 0;
+	for (i = 0 ; i < len ; i++)
+		buffer[i] = i2c_raw_read(base, chip, addr + i);
+
+	return 0;
+}
+
+/*
+ * i2c_write: -  Write multiple bytes to an i2c device
+ *
+ * The higher level routines take into account that this function is only
+ * called with len < page length of the device (see configuration file)
+ *
+ * @chip:   address of the chip which is to be written
+ * @addr:   i2c data address within the chip
+ * @alen:   length of the i2c data address (1..2 bytes)
+ * @buffer: where to find the data to be written
+ * @len:    how much byte do we want to read
+ * @return: 0 in case of success
+ */
+int i2c_write(u8 chip, u32 addr, int alen, u8 *buffer, int len)
+{
+	int i = 0;
+	for (i = 0; i < len ; i++)
+		i2c_raw_write(base, chip, addr + i, buffer[i]);
+
+	return 0;
+}
+
+/*
+ * i2c_probe: - Test if a chip answers for a given i2c address
+ *
+ * @chip:   address of the chip which is searched for
+ * @return: 0 if a chip was found, -1 otherwhise
+ */
+int i2c_probe(u8 chip)
+{
+	return 0;
+}