summaryrefslogtreecommitdiff
path: root/cpu/mpc5xxx/i2c.c
diff options
context:
space:
mode:
Diffstat (limited to 'cpu/mpc5xxx/i2c.c')
-rw-r--r--cpu/mpc5xxx/i2c.c338
1 files changed, 338 insertions, 0 deletions
diff --git a/cpu/mpc5xxx/i2c.c b/cpu/mpc5xxx/i2c.c
new file mode 100644
index 0000000..640d140
--- /dev/null
+++ b/cpu/mpc5xxx/i2c.c
@@ -0,0 +1,338 @@
+/*
+ * (C) Copyright 2003
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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>
+
+#ifdef CONFIG_HARD_I2C
+
+#include <mpc5xxx.h>
+#include <i2c.h>
+
+#ifdef CFG_I2C_MODULE
+#define I2C_BASE MPC5XXX_I2C2
+#else
+#define I2C_BASE MPC5XXX_I2C1
+#endif
+
+#define I2C_TIMEOUT 100
+#define I2C_RETRIES 3
+
+static int mpc_reg_in (volatile u32 *reg);
+static void mpc_reg_out (volatile u32 *reg, int val, int mask);
+static int wait_for_bb (void);
+static int wait_for_pin (int *status);
+static int do_address (uchar chip, char rdwr_flag);
+static int send_bytes (uchar chip, char *buf, int len);
+static int receive_bytes (uchar chip, char *buf, int len);
+
+static int mpc_reg_in(volatile u32 *reg)
+{
+ return *reg >> 24;
+ __asm__ __volatile__ ("eieio");
+}
+
+static void mpc_reg_out(volatile u32 *reg, int val, int mask)
+{
+ int tmp;
+
+ if (!mask) {
+ *reg = val << 24;
+ } else {
+ tmp = mpc_reg_in(reg);
+ *reg = ((tmp & ~mask) | (val & mask)) << 24;
+ }
+ __asm__ __volatile__ ("eieio");
+
+ return;
+}
+
+static int wait_for_bb(void)
+{
+ struct mpc5xxx_i2c *regs = (struct mpc5xxx_i2c *)I2C_BASE;
+ int timeout = I2C_TIMEOUT;
+ int status;
+
+ status = mpc_reg_in(&regs->msr);
+
+ while (timeout-- && (status & I2C_BB)) {
+#if 1
+ volatile int temp;
+ mpc_reg_out(&regs->mcr, I2C_STA, I2C_STA);
+ temp = mpc_reg_in(&regs->mdr);
+ mpc_reg_out(&regs->mcr, 0, I2C_STA);
+ mpc_reg_out(&regs->mcr, 0, 0);
+ mpc_reg_out(&regs->mcr, I2C_EN, 0);
+#endif
+ udelay(1000);
+ status = mpc_reg_in(&regs->msr);
+ }
+
+ return (status & I2C_BB);
+}
+
+static int wait_for_pin(int *status)
+{
+ struct mpc5xxx_i2c *regs = (struct mpc5xxx_i2c *)I2C_BASE;
+ int timeout = I2C_TIMEOUT;
+
+ *status = mpc_reg_in(&regs->msr);
+
+ while (timeout-- && !(*status & I2C_IF)) {
+ udelay(1000);
+ *status = mpc_reg_in(&regs->msr);
+ }
+
+ if (!(*status & I2C_IF)) {
+ return -1;
+ }
+
+ mpc_reg_out(&regs->msr, 0, I2C_IF);
+
+ return 0;
+}
+
+static int do_address(uchar chip, char rdwr_flag)
+{
+ struct mpc5xxx_i2c *regs = (struct mpc5xxx_i2c *)I2C_BASE;
+ int status;
+
+ chip <<= 1;
+
+ if (rdwr_flag) {
+ chip |= 1;
+ }
+
+ mpc_reg_out(&regs->mcr, I2C_TX, I2C_TX);
+ mpc_reg_out(&regs->mdr, chip, 0);
+
+ if (wait_for_pin(&status)) {
+ return -2;
+ }
+
+ if (status & I2C_RXAK) {
+ return -3;
+ }
+
+ return 0;
+}
+
+static int send_bytes(uchar chip, char *buf, int len)
+{
+ struct mpc5xxx_i2c *regs = (struct mpc5xxx_i2c *)I2C_BASE;
+ int wrcount;
+ int status;
+
+ for (wrcount = 0; wrcount < len; ++wrcount) {
+
+ mpc_reg_out(&regs->mdr, buf[wrcount], 0);
+
+ if (wait_for_pin(&status)) {
+ break;
+ }
+
+ if (status & I2C_RXAK) {
+ break;
+ }
+
+ }
+
+ return !(wrcount == len);
+}
+
+static int receive_bytes(uchar chip, char *buf, int len)
+{
+ struct mpc5xxx_i2c *regs = (struct mpc5xxx_i2c *)I2C_BASE;
+ int dummy = 1;
+ int rdcount = 0;
+ int status;
+ int i;
+
+ mpc_reg_out(&regs->mcr, 0, I2C_TX);
+
+ for (i = 0; i < len; ++i) {
+ buf[rdcount] = mpc_reg_in(&regs->mdr);
+
+ if (dummy) {
+ dummy = 0;
+ } else {
+ rdcount++;
+ }
+
+
+ if (wait_for_pin(&status)) {
+ return -4;
+ }
+ }
+
+ mpc_reg_out(&regs->mcr, I2C_TXAK, I2C_TXAK);
+ buf[rdcount++] = mpc_reg_in(&regs->mdr);
+
+ if (wait_for_pin(&status)) {
+ return -5;
+ }
+
+ mpc_reg_out(&regs->mcr, 0, I2C_TXAK);
+
+ return 0;
+}
+
+/**************** I2C API ****************/
+
+void i2c_init(int speed, int saddr)
+{
+ struct mpc5xxx_i2c *regs = (struct mpc5xxx_i2c *)I2C_BASE;
+
+ mpc_reg_out(&regs->mcr, 0, 0);
+ mpc_reg_out(&regs->madr, saddr << 1, 0);
+
+ /* Set clock
+ */
+ mpc_reg_out(&regs->mfdr, speed, 0);
+
+ /* Enable module
+ */
+ mpc_reg_out(&regs->mcr, I2C_EN, I2C_INIT_MASK);
+ mpc_reg_out(&regs->msr, 0, I2C_IF);
+
+ return;
+}
+
+int i2c_probe(uchar chip)
+{
+ struct mpc5xxx_i2c *regs = (struct mpc5xxx_i2c *)I2C_BASE;
+ int i;
+
+ for (i = 0; i < I2C_RETRIES; i++) {
+ mpc_reg_out(&regs->mcr, I2C_STA, I2C_STA);
+
+ if (! do_address(chip, 0)) {
+ mpc_reg_out(&regs->mcr, 0, I2C_STA);
+ break;
+ }
+
+ mpc_reg_out(&regs->mcr, 0, I2C_STA);
+ udelay(500);
+ }
+
+ return (i == I2C_RETRIES);
+}
+
+int i2c_read(uchar chip, uint addr, int alen, uchar *buf, int len)
+{
+ uchar xaddr[4];
+ struct mpc5xxx_i2c * regs = (struct mpc5xxx_i2c *)I2C_BASE;
+ int ret = -1;
+
+ xaddr[0] = (addr >> 24) & 0xFF;
+ xaddr[1] = (addr >> 16) & 0xFF;
+ xaddr[2] = (addr >> 8) & 0xFF;
+ xaddr[3] = addr & 0xFF;
+
+ if (wait_for_bb()) {
+ printf("i2c_read: bus is busy\n");
+ goto Done;
+ }
+
+ mpc_reg_out(&regs->mcr, I2C_STA, I2C_STA);
+ if (do_address(chip, 0)) {
+ printf("i2c_read: failed to address chip\n");
+ goto Done;
+ }
+
+ if (send_bytes(chip, &xaddr[4-alen], alen)) {
+ printf("i2c_read: send_bytes failed\n");
+ goto Done;
+ }
+
+ mpc_reg_out(&regs->mcr, I2C_RSTA, I2C_RSTA);
+ if (do_address(chip, 1)) {
+ printf("i2c_read: failed to address chip\n");
+ goto Done;
+ }
+
+ if (receive_bytes(chip, buf, len)) {
+ printf("i2c_read: receive_bytes failed\n");
+ goto Done;
+ }
+
+ ret = 0;
+Done:
+ mpc_reg_out(&regs->mcr, 0, I2C_STA);
+ return ret;
+}
+
+int i2c_write(uchar chip, uint addr, int alen, uchar *buf, int len)
+{
+ uchar xaddr[4];
+ struct mpc5xxx_i2c *regs = (struct mpc5xxx_i2c *)I2C_BASE;
+ int ret = -1;
+
+ xaddr[0] = (addr >> 24) & 0xFF;
+ xaddr[1] = (addr >> 16) & 0xFF;
+ xaddr[2] = (addr >> 8) & 0xFF;
+ xaddr[3] = addr & 0xFF;
+
+ if (wait_for_bb()) {
+ printf("i2c_write: bus is busy\n");
+ goto Done;
+ }
+
+ mpc_reg_out(&regs->mcr, I2C_STA, I2C_STA);
+ if (do_address(chip, 0)) {
+ printf("i2c_write: failed to address chip\n");
+ goto Done;
+ }
+
+ if (send_bytes(chip, &xaddr[4-alen], alen)) {
+ printf("i2c_write: send_bytes failed\n");
+ goto Done;
+ }
+
+ if (send_bytes(chip, buf, len)) {
+ printf("i2c_write: send_bytes failed\n");
+ goto Done;
+ }
+
+ ret = 0;
+Done:
+ mpc_reg_out(&regs->mcr, 0, I2C_STA);
+ return ret;
+}
+
+uchar i2c_reg_read(uchar chip, uchar reg)
+{
+ char buf;
+
+ i2c_read(chip, reg, 1, &buf, 1);
+
+ return buf;
+}
+
+void i2c_reg_write(uchar chip, uchar reg, uchar val)
+{
+ i2c_write(chip, reg, 1, &val, 1);
+
+ return;
+}
+
+#endif /* CONFIG_HARD_I2C */
generated by cgit v1.1 at 2024-11-02 15:50:52 +0000