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-rw-r--r--cpu/arm926ejs/davinci/i2c.c351
1 files changed, 351 insertions, 0 deletions
diff --git a/cpu/arm926ejs/davinci/i2c.c b/cpu/arm926ejs/davinci/i2c.c
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+++ b/cpu/arm926ejs/davinci/i2c.c
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+/*
+ * TI DaVinci (TMS320DM644x) I2C driver.
+ *
+ * Copyright (C) 2007 Sergey Kubushyn <ksi@koi8.net>
+ *
+ * --------------------------------------------------------
+ *
+ * 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_DRIVER_DAVINCI_I2C
+
+#include <i2c.h>
+#include <asm/arch/hardware.h>
+#include <asm/arch/i2c_defs.h>
+
+#define CHECK_NACK() \
+ do {\
+ if (tmp & (I2C_TIMEOUT | I2C_STAT_NACK)) {\
+ REG(I2C_CON) = 0;\
+ return(1);\
+ }\
+ } while (0)
+
+
+static int wait_for_bus(void)
+{
+ int stat, timeout;
+
+ REG(I2C_STAT) = 0xffff;
+
+ for (timeout = 0; timeout < 10; timeout++) {
+ if (!((stat = REG(I2C_STAT)) & I2C_STAT_BB)) {
+ REG(I2C_STAT) = 0xffff;
+ return(0);
+ }
+
+ REG(I2C_STAT) = stat;
+ udelay(50000);
+ }
+
+ REG(I2C_STAT) = 0xffff;
+ return(1);
+}
+
+
+static int poll_i2c_irq(int mask)
+{
+ int stat, timeout;
+
+ for (timeout = 0; timeout < 10; timeout++) {
+ udelay(1000);
+ stat = REG(I2C_STAT);
+ if (stat & mask) {
+ return(stat);
+ }
+ }
+
+ REG(I2C_STAT) = 0xffff;
+ return(stat | I2C_TIMEOUT);
+}
+
+
+void flush_rx(void)
+{
+ int dummy;
+
+ while (1) {
+ if (!(REG(I2C_STAT) & I2C_STAT_RRDY))
+ break;
+
+ dummy = REG(I2C_DRR);
+ REG(I2C_STAT) = I2C_STAT_RRDY;
+ udelay(1000);
+ }
+}
+
+
+void i2c_init(int speed, int slaveadd)
+{
+ u_int32_t div, psc;
+
+ if (REG(I2C_CON) & I2C_CON_EN) {
+ REG(I2C_CON) = 0;
+ udelay (50000);
+ }
+
+ psc = 2;
+ div = (CFG_HZ_CLOCK / ((psc + 1) * speed)) - 10; /* SCLL + SCLH */
+ REG(I2C_PSC) = psc; /* 27MHz / (2 + 1) = 9MHz */
+ REG(I2C_SCLL) = (div * 50) / 100; /* 50% Duty */
+ REG(I2C_SCLH) = div - REG(I2C_SCLL);
+
+ REG(I2C_OA) = slaveadd;
+ REG(I2C_CNT) = 0;
+
+ /* Interrupts must be enabled or I2C module won't work */
+ REG(I2C_IE) = I2C_IE_SCD_IE | I2C_IE_XRDY_IE |
+ I2C_IE_RRDY_IE | I2C_IE_ARDY_IE | I2C_IE_NACK_IE;
+
+ /* Now enable I2C controller (get it out of reset) */
+ REG(I2C_CON) = I2C_CON_EN;
+
+ udelay(1000);
+}
+
+
+int i2c_probe(u_int8_t chip)
+{
+ int rc = 1;
+
+ if (chip == REG(I2C_OA)) {
+ return(rc);
+ }
+
+ REG(I2C_CON) = 0;
+ if (wait_for_bus()) {return(1);}
+
+ /* try to read one byte from current (or only) address */
+ REG(I2C_CNT) = 1;
+ REG(I2C_SA) = chip;
+ REG(I2C_CON) = (I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_STP);
+ udelay (50000);
+
+ if (!(REG(I2C_STAT) & I2C_STAT_NACK)) {
+ rc = 0;
+ flush_rx();
+ REG(I2C_STAT) = 0xffff;
+ } else {
+ REG(I2C_STAT) = 0xffff;
+ REG(I2C_CON) |= I2C_CON_STP;
+ udelay(20000);
+ if (wait_for_bus()) {return(1);}
+ }
+
+ flush_rx();
+ REG(I2C_STAT) = 0xffff;
+ REG(I2C_CNT) = 0;
+ return(rc);
+}
+
+
+int i2c_read(u_int8_t chip, u_int32_t addr, int alen, u_int8_t *buf, int len)
+{
+ u_int32_t tmp;
+ int i;
+
+ if ((alen < 0) || (alen > 2)) {
+ printf("%s(): bogus address length %x\n", __FUNCTION__, alen);
+ return(1);
+ }
+
+ if (wait_for_bus()) {return(1);}
+
+ if (alen != 0) {
+ /* Start address phase */
+ tmp = I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_TRX;
+ REG(I2C_CNT) = alen;
+ REG(I2C_SA) = chip;
+ REG(I2C_CON) = tmp;
+
+ tmp = poll_i2c_irq(I2C_STAT_XRDY | I2C_STAT_NACK);
+
+ CHECK_NACK();
+
+ switch (alen) {
+ case 2:
+ /* Send address MSByte */
+ if (tmp & I2C_STAT_XRDY) {
+ REG(I2C_DXR) = (addr >> 8) & 0xff;
+ } else {
+ REG(I2C_CON) = 0;
+ return(1);
+ }
+
+ tmp = poll_i2c_irq(I2C_STAT_XRDY | I2C_STAT_NACK);
+
+ CHECK_NACK();
+ /* No break, fall through */
+ case 1:
+ /* Send address LSByte */
+ if (tmp & I2C_STAT_XRDY) {
+ REG(I2C_DXR) = addr & 0xff;
+ } else {
+ REG(I2C_CON) = 0;
+ return(1);
+ }
+
+ tmp = poll_i2c_irq(I2C_STAT_XRDY | I2C_STAT_NACK | I2C_STAT_ARDY);
+
+ CHECK_NACK();
+
+ if (!(tmp & I2C_STAT_ARDY)) {
+ REG(I2C_CON) = 0;
+ return(1);
+ }
+ }
+ }
+
+ /* Address phase is over, now read 'len' bytes and stop */
+ tmp = I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_STP;
+ REG(I2C_CNT) = len & 0xffff;
+ REG(I2C_SA) = chip;
+ REG(I2C_CON) = tmp;
+
+ for (i = 0; i < len; i++) {
+ tmp = poll_i2c_irq(I2C_STAT_RRDY | I2C_STAT_NACK | I2C_STAT_ROVR);
+
+ CHECK_NACK();
+
+ if (tmp & I2C_STAT_RRDY) {
+ buf[i] = REG(I2C_DRR);
+ } else {
+ REG(I2C_CON) = 0;
+ return(1);
+ }
+ }
+
+ tmp = poll_i2c_irq(I2C_STAT_SCD | I2C_STAT_NACK);
+
+ CHECK_NACK();
+
+ if (!(tmp & I2C_STAT_SCD)) {
+ REG(I2C_CON) = 0;
+ return(1);
+ }
+
+ flush_rx();
+ REG(I2C_STAT) = 0xffff;
+ REG(I2C_CNT) = 0;
+ REG(I2C_CON) = 0;
+
+ return(0);
+}
+
+
+int i2c_write(u_int8_t chip, u_int32_t addr, int alen, u_int8_t *buf, int len)
+{
+ u_int32_t tmp;
+ int i;
+
+ if ((alen < 0) || (alen > 2)) {
+ printf("%s(): bogus address length %x\n", __FUNCTION__, alen);
+ return(1);
+ }
+ if (len < 0) {
+ printf("%s(): bogus length %x\n", __FUNCTION__, len);
+ return(1);
+ }
+
+ if (wait_for_bus()) {return(1);}
+
+ /* Start address phase */
+ tmp = I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_TRX | I2C_CON_STP;
+ REG(I2C_CNT) = (alen == 0) ? len & 0xffff : (len & 0xffff) + alen;
+ REG(I2C_SA) = chip;
+ REG(I2C_CON) = tmp;
+
+ switch (alen) {
+ case 2:
+ /* Send address MSByte */
+ tmp = poll_i2c_irq(I2C_STAT_XRDY | I2C_STAT_NACK);
+
+ CHECK_NACK();
+
+ if (tmp & I2C_STAT_XRDY) {
+ REG(I2C_DXR) = (addr >> 8) & 0xff;
+ } else {
+ REG(I2C_CON) = 0;
+ return(1);
+ }
+ /* No break, fall through */
+ case 1:
+ /* Send address LSByte */
+ tmp = poll_i2c_irq(I2C_STAT_XRDY | I2C_STAT_NACK);
+
+ CHECK_NACK();
+
+ if (tmp & I2C_STAT_XRDY) {
+ REG(I2C_DXR) = addr & 0xff;
+ } else {
+ REG(I2C_CON) = 0;
+ return(1);
+ }
+ }
+
+ for (i = 0; i < len; i++) {
+ tmp = poll_i2c_irq(I2C_STAT_XRDY | I2C_STAT_NACK);
+
+ CHECK_NACK();
+
+ if (tmp & I2C_STAT_XRDY) {
+ REG(I2C_DXR) = buf[i];
+ } else {
+ return(1);
+ }
+ }
+
+ tmp = poll_i2c_irq(I2C_STAT_SCD | I2C_STAT_NACK);
+
+ CHECK_NACK();
+
+ if (!(tmp & I2C_STAT_SCD)) {
+ REG(I2C_CON) = 0;
+ return(1);
+ }
+
+ flush_rx();
+ REG(I2C_STAT) = 0xffff;
+ REG(I2C_CNT) = 0;
+ REG(I2C_CON) = 0;
+
+ return(0);
+}
+
+
+u_int8_t i2c_reg_read(u_int8_t chip, u_int8_t reg)
+{
+ u_int8_t tmp;
+
+ i2c_read(chip, reg, 1, &tmp, 1);
+ return(tmp);
+}
+
+
+void i2c_reg_write(u_int8_t chip, u_int8_t reg, u_int8_t val)
+{
+ u_int8_t tmp;
+
+ i2c_write(chip, reg, 1, &tmp, 1);
+}
+
+#endif /* CONFIG_DRIVER_DAVINCI_I2C */
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