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Diffstat (limited to 'drivers/i2c/fsl_i2c.c')
-rw-r--r--drivers/i2c/fsl_i2c.c295
1 files changed, 295 insertions, 0 deletions
diff --git a/drivers/i2c/fsl_i2c.c b/drivers/i2c/fsl_i2c.c
new file mode 100644
index 0000000..22485ea
--- /dev/null
+++ b/drivers/i2c/fsl_i2c.c
@@ -0,0 +1,295 @@
+/*
+ * Copyright 2006 Freescale Semiconductor, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * Version 2 as published by the Free Software Foundation.
+ *
+ * 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>
+
+#ifdef CONFIG_FSL_I2C
+#ifdef CONFIG_HARD_I2C
+
+#include <command.h>
+#include <i2c.h> /* Functional interface */
+
+#include <asm/io.h>
+#include <asm/fsl_i2c.h> /* HW definitions */
+
+#define I2C_TIMEOUT (CFG_HZ / 4)
+
+#define I2C_READ_BIT 1
+#define I2C_WRITE_BIT 0
+
+/* Initialize the bus pointer to whatever one the SPD EEPROM is on.
+ * Default is bus 0. This is necessary because the DDR initialization
+ * runs from ROM, and we can't switch buses because we can't modify
+ * the global variables.
+ */
+#ifdef CFG_SPD_BUS_NUM
+static unsigned int i2c_bus_num __attribute__ ((section ("data"))) = CFG_SPD_BUS_NUM;
+#else
+static unsigned int i2c_bus_num __attribute__ ((section ("data"))) = 0;
+#endif
+
+static volatile struct fsl_i2c *i2c_dev[2] = {
+ (struct fsl_i2c *) (CFG_IMMR + CFG_I2C_OFFSET),
+#ifdef CFG_I2C2_OFFSET
+ (struct fsl_i2c *) (CFG_IMMR + CFG_I2C2_OFFSET)
+#endif
+};
+
+void
+i2c_init(int speed, int slaveadd)
+{
+ volatile struct fsl_i2c *dev;
+
+ dev = (struct fsl_i2c *) (CFG_IMMR + CFG_I2C_OFFSET);
+
+ writeb(0, &dev->cr); /* stop I2C controller */
+ udelay(5); /* let it shutdown in peace */
+ writeb(0x3F, &dev->fdr); /* set bus speed */
+ writeb(0x3F, &dev->dfsrr); /* set default filter */
+ writeb(slaveadd << 1, &dev->adr); /* write slave address */
+ writeb(0x0, &dev->sr); /* clear status register */
+ writeb(I2C_CR_MEN, &dev->cr); /* start I2C controller */
+
+#ifdef CFG_I2C2_OFFSET
+ dev = (struct fsl_i2c *) (CFG_IMMR + CFG_I2C2_OFFSET);
+
+ writeb(0, &dev->cr); /* stop I2C controller */
+ udelay(5); /* let it shutdown in peace */
+ writeb(0x3F, &dev->fdr); /* set bus speed */
+ writeb(0x3F, &dev->dfsrr); /* set default filter */
+ writeb(slaveadd << 1, &dev->adr); /* write slave address */
+ writeb(0x0, &dev->sr); /* clear status register */
+ writeb(I2C_CR_MEN, &dev->cr); /* start I2C controller */
+#endif /* CFG_I2C2_OFFSET */
+}
+
+static __inline__ int
+i2c_wait4bus(void)
+{
+ ulong timeval = get_timer(0);
+
+ while (readb(&i2c_dev[i2c_bus_num]->sr) & I2C_SR_MBB) {
+ if (get_timer(timeval) > I2C_TIMEOUT) {
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
+static __inline__ int
+i2c_wait(int write)
+{
+ u32 csr;
+ ulong timeval = get_timer(0);
+
+ do {
+ csr = readb(&i2c_dev[i2c_bus_num]->sr);
+ if (!(csr & I2C_SR_MIF))
+ continue;
+
+ writeb(0x0, &i2c_dev[i2c_bus_num]->sr);
+
+ if (csr & I2C_SR_MAL) {
+ debug("i2c_wait: MAL\n");
+ return -1;
+ }
+
+ if (!(csr & I2C_SR_MCF)) {
+ debug("i2c_wait: unfinished\n");
+ return -1;
+ }
+
+ if (write == I2C_WRITE_BIT && (csr & I2C_SR_RXAK)) {
+ debug("i2c_wait: No RXACK\n");
+ return -1;
+ }
+
+ return 0;
+ } while (get_timer (timeval) < I2C_TIMEOUT);
+
+ debug("i2c_wait: timed out\n");
+ return -1;
+}
+
+static __inline__ int
+i2c_write_addr (u8 dev, u8 dir, int rsta)
+{
+ writeb(I2C_CR_MEN | I2C_CR_MSTA | I2C_CR_MTX
+ | (rsta ? I2C_CR_RSTA : 0),
+ &i2c_dev[i2c_bus_num]->cr);
+
+ writeb((dev << 1) | dir, &i2c_dev[i2c_bus_num]->dr);
+
+ if (i2c_wait(I2C_WRITE_BIT) < 0)
+ return 0;
+
+ return 1;
+}
+
+static __inline__ int
+__i2c_write(u8 *data, int length)
+{
+ int i;
+
+ writeb(I2C_CR_MEN | I2C_CR_MSTA | I2C_CR_MTX,
+ &i2c_dev[i2c_bus_num]->cr);
+
+ for (i = 0; i < length; i++) {
+ writeb(data[i], &i2c_dev[i2c_bus_num]->dr);
+
+ if (i2c_wait(I2C_WRITE_BIT) < 0)
+ break;
+ }
+
+ return i;
+}
+
+static __inline__ int
+__i2c_read(u8 *data, int length)
+{
+ int i;
+
+ writeb(I2C_CR_MEN | I2C_CR_MSTA | ((length == 1) ? I2C_CR_TXAK : 0),
+ &i2c_dev[i2c_bus_num]->cr);
+
+ /* dummy read */
+ readb(&i2c_dev[i2c_bus_num]->dr);
+
+ for (i = 0; i < length; i++) {
+ if (i2c_wait(I2C_READ_BIT) < 0)
+ break;
+
+ /* Generate ack on last next to last byte */
+ if (i == length - 2)
+ writeb(I2C_CR_MEN | I2C_CR_MSTA | I2C_CR_TXAK,
+ &i2c_dev[i2c_bus_num]->cr);
+
+ /* Generate stop on last byte */
+ if (i == length - 1)
+ writeb(I2C_CR_MEN | I2C_CR_TXAK, &i2c_dev[i2c_bus_num]->cr);
+
+ data[i] = readb(&i2c_dev[i2c_bus_num]->dr);
+ }
+
+ return i;
+}
+
+int
+i2c_read(u8 dev, uint addr, int alen, u8 *data, int length)
+{
+ int i = -1; /* signal error */
+ u8 *a = (u8*)&addr;
+
+ if (i2c_wait4bus() >= 0
+ && i2c_write_addr(dev, I2C_WRITE_BIT, 0) != 0
+ && __i2c_write(&a[4 - alen], alen) == alen)
+ i = 0; /* No error so far */
+
+ if (length
+ && i2c_write_addr(dev, I2C_READ_BIT, 1) != 0)
+ i = __i2c_read(data, length);
+
+ writeb(I2C_CR_MEN, &i2c_dev[i2c_bus_num]->cr);
+
+ if (i == length)
+ return 0;
+
+ return -1;
+}
+
+int
+i2c_write(u8 dev, uint addr, int alen, u8 *data, int length)
+{
+ int i = -1; /* signal error */
+ u8 *a = (u8*)&addr;
+
+ if (i2c_wait4bus() >= 0
+ && i2c_write_addr(dev, I2C_WRITE_BIT, 0) != 0
+ && __i2c_write(&a[4 - alen], alen) == alen) {
+ i = __i2c_write(data, length);
+ }
+
+ writeb(I2C_CR_MEN, &i2c_dev[i2c_bus_num]->cr);
+
+ if (i == length)
+ return 0;
+
+ return -1;
+}
+
+int
+i2c_probe(uchar chip)
+{
+ /* For unknow reason the controller will ACK when
+ * probing for a slave with the same address, so skip
+ * it.
+ */
+ if (chip == (readb(&i2c_dev[i2c_bus_num]->adr) >> 1))
+ return -1;
+
+ return i2c_read(chip, 0, 0, NULL, 0);
+}
+
+uchar
+i2c_reg_read(uchar i2c_addr, uchar reg)
+{
+ uchar buf[1];
+
+ i2c_read(i2c_addr, reg, 1, buf, 1);
+
+ return buf[0];
+}
+
+void
+i2c_reg_write(uchar i2c_addr, uchar reg, uchar val)
+{
+ i2c_write(i2c_addr, reg, 1, &val, 1);
+}
+
+int i2c_set_bus_num(unsigned int bus)
+{
+#ifdef CFG_I2C2_OFFSET
+ if (bus > 1) {
+#else
+ if (bus > 0) {
+#endif
+ return -1;
+ }
+
+ i2c_bus_num = bus;
+
+ return 0;
+}
+
+int i2c_set_bus_speed(unsigned int speed)
+{
+ return -1;
+}
+
+unsigned int i2c_get_bus_num(void)
+{
+ return i2c_bus_num;
+}
+
+unsigned int i2c_get_bus_speed(void)
+{
+ return 0;
+}
+#endif /* CONFIG_HARD_I2C */
+#endif /* CONFIG_FSL_I2C */