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-rw-r--r--cpu/blackfin/i2c.c444
1 files changed, 444 insertions, 0 deletions
diff --git a/cpu/blackfin/i2c.c b/cpu/blackfin/i2c.c
new file mode 100644
index 000000000..47be2587d
--- /dev/null
+++ b/cpu/blackfin/i2c.c
@@ -0,0 +1,444 @@
+/*
+ * i2c.c - driver for Blackfin on-chip TWI/I2C
+ *
+ * Copyright (c) 2006-2008 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <common.h>
+
+#ifdef CONFIG_HARD_I2C
+
+#include <asm/blackfin.h>
+#include <i2c.h>
+#include <asm/io.h>
+#include <asm/mach-common/bits/twi.h>
+
+/* Two-Wire Interface (0xFFC01400 - 0xFFC014FF) */
+#ifdef TWI0_CLKDIV
+#define bfin_read_TWI_CLKDIV() bfin_read_TWI0_CLKDIV()
+#define bfin_write_TWI_CLKDIV(val) bfin_write_TWI0_CLKDIV(val)
+#define bfin_read_TWI_CONTROL() bfin_read_TWI0_CONTROL()
+#define bfin_write_TWI_CONTROL(val) bfin_write_TWI0_CONTROL(val)
+#define bfin_read_TWI_SLAVE_CTL() bfin_read_TWI0_SLAVE_CTL()
+#define bfin_write_TWI_SLAVE_CTL(val) bfin_write_TWI0_SLAVE_CTL(val)
+#define bfin_read_TWI_SLAVE_STAT() bfin_read_TWI0_SLAVE_STAT()
+#define bfin_write_TWI_SLAVE_STAT(val) bfin_write_TWI0_SLAVE_STAT(val)
+#define bfin_read_TWI_SLAVE_ADDR() bfin_read_TWI0_SLAVE_ADDR()
+#define bfin_write_TWI_SLAVE_ADDR(val) bfin_write_TWI0_SLAVE_ADDR(val)
+#define bfin_read_TWI_MASTER_CTL() bfin_read_TWI0_MASTER_CTL()
+#define bfin_write_TWI_MASTER_CTL(val) bfin_write_TWI0_MASTER_CTL(val)
+#define bfin_read_TWI_MASTER_STAT() bfin_read_TWI0_MASTER_STAT()
+#define bfin_write_TWI_MASTER_STAT(val) bfin_write_TWI0_MASTER_STAT(val)
+#define bfin_read_TWI_MASTER_ADDR() bfin_read_TWI0_MASTER_ADDR()
+#define bfin_write_TWI_MASTER_ADDR(val) bfin_write_TWI0_MASTER_ADDR(val)
+#define bfin_read_TWI_INT_STAT() bfin_read_TWI0_INT_STAT()
+#define bfin_write_TWI_INT_STAT(val) bfin_write_TWI0_INT_STAT(val)
+#define bfin_read_TWI_INT_MASK() bfin_read_TWI0_INT_MASK()
+#define bfin_write_TWI_INT_MASK(val) bfin_write_TWI0_INT_MASK(val)
+#define bfin_read_TWI_FIFO_CTL() bfin_read_TWI0_FIFO_CTL()
+#define bfin_write_TWI_FIFO_CTL(val) bfin_write_TWI0_FIFO_CTL(val)
+#define bfin_read_TWI_FIFO_STAT() bfin_read_TWI0_FIFO_STAT()
+#define bfin_write_TWI_FIFO_STAT(val) bfin_write_TWI0_FIFO_STAT(val)
+#define bfin_read_TWI_XMT_DATA8() bfin_read_TWI0_XMT_DATA8()
+#define bfin_write_TWI_XMT_DATA8(val) bfin_write_TWI0_XMT_DATA8(val)
+#define bfin_read_TWI_XMT_DATA_16() bfin_read_TWI0_XMT_DATA16()
+#define bfin_write_TWI_XMT_DATA16(val) bfin_write_TWI0_XMT_DATA16(val)
+#define bfin_read_TWI_RCV_DATA8() bfin_read_TWI0_RCV_DATA8()
+#define bfin_write_TWI_RCV_DATA8(val) bfin_write_TWI0_RCV_DATA8(val)
+#define bfin_read_TWI_RCV_DATA16() bfin_read_TWI0_RCV_DATA16()
+#define bfin_write_TWI_RCV_DATA16(val) bfin_write_TWI0_RCV_DATA16(val)
+#endif
+
+#ifdef DEBUG_I2C
+#define PRINTD(fmt,args...) do { \
+ DECLARE_GLOBAL_DATA_PTR; \
+ if (gd->have_console) \
+ printf(fmt ,##args); \
+ } while (0)
+#else
+#define PRINTD(fmt,args...)
+#endif
+
+#ifndef CONFIG_TWICLK_KHZ
+#define CONFIG_TWICLK_KHZ 50
+#endif
+
+/* All transfers are described by this data structure */
+struct i2c_msg {
+ u16 addr; /* slave address */
+ u16 flags;
+#define I2C_M_STOP 0x2
+#define I2C_M_RD 0x1
+ u16 len; /* msg length */
+ u8 *buf; /* pointer to msg data */
+};
+
+/**
+ * i2c_reset: - reset the host controller
+ */
+static void i2c_reset(void)
+{
+ /* Disable TWI */
+ bfin_write_TWI_CONTROL(0);
+ SSYNC();
+
+ /* Set TWI internal clock as 10MHz */
+ bfin_write_TWI_CONTROL(((get_sclk() / 1024 / 1024 + 5) / 10) & 0x7F);
+
+ /* Set Twi interface clock as specified */
+ if (CONFIG_TWICLK_KHZ > 400)
+ bfin_write_TWI_CLKDIV(((5 * 1024 / 400) << 8) | ((5 * 1024 /
+ 400) & 0xFF));
+ else
+ bfin_write_TWI_CLKDIV(((5 * 1024 /
+ CONFIG_TWICLK_KHZ) << 8) | ((5 * 1024 /
+ CONFIG_TWICLK_KHZ)
+ & 0xFF));
+
+ /* Enable TWI */
+ bfin_write_TWI_CONTROL(bfin_read_TWI_CONTROL() | TWI_ENA);
+ SSYNC();
+}
+
+int wait_for_completion(struct i2c_msg *msg, int timeout_count)
+{
+ unsigned short twi_int_stat;
+ unsigned short mast_stat;
+ int i;
+
+ for (i = 0; i < timeout_count; i++) {
+ twi_int_stat = bfin_read_TWI_INT_STAT();
+ mast_stat = bfin_read_TWI_MASTER_STAT();
+
+ if (XMTSERV & twi_int_stat) {
+ /* Transmit next data */
+ if (msg->len > 0) {
+ bfin_write_TWI_XMT_DATA8(*(msg->buf++));
+ msg->len--;
+ } else if (msg->flags & I2C_M_STOP)
+ bfin_write_TWI_MASTER_CTL
+ (bfin_read_TWI_MASTER_CTL() | STOP);
+ SSYNC();
+ /* Clear status */
+ bfin_write_TWI_INT_STAT(XMTSERV);
+ SSYNC();
+ i = 0;
+ }
+ if (RCVSERV & twi_int_stat) {
+ if (msg->len > 0) {
+ /* Receive next data */
+ *(msg->buf++) = bfin_read_TWI_RCV_DATA8();
+ msg->len--;
+ } else if (msg->flags & I2C_M_STOP) {
+ bfin_write_TWI_MASTER_CTL
+ (bfin_read_TWI_MASTER_CTL() | STOP);
+ SSYNC();
+ }
+ /* Clear interrupt source */
+ bfin_write_TWI_INT_STAT(RCVSERV);
+ SSYNC();
+ i = 0;
+ }
+ if (MERR & twi_int_stat) {
+ bfin_write_TWI_INT_STAT(MERR);
+ bfin_write_TWI_INT_MASK(0);
+ bfin_write_TWI_MASTER_STAT(0x3e);
+ bfin_write_TWI_MASTER_CTL(0);
+ SSYNC();
+ /*
+ * if both err and complete int stats are set,
+ * return proper results.
+ */
+ if (MCOMP & twi_int_stat) {
+ bfin_write_TWI_INT_STAT(MCOMP);
+ bfin_write_TWI_INT_MASK(0);
+ bfin_write_TWI_MASTER_CTL(0);
+ SSYNC();
+ /*
+ * If it is a quick transfer,
+ * only address bug no data, not an err.
+ */
+ if (msg->len == 0 && mast_stat & BUFRDERR)
+ return 0;
+ /*
+ * If address not acknowledged return -3,
+ * else return 0.
+ */
+ else if (!(mast_stat & ANAK))
+ return 0;
+ else
+ return -3;
+ }
+ return -1;
+ }
+ if (MCOMP & twi_int_stat) {
+ bfin_write_TWI_INT_STAT(MCOMP);
+ SSYNC();
+ bfin_write_TWI_INT_MASK(0);
+ bfin_write_TWI_MASTER_CTL(0);
+ SSYNC();
+ return 0;
+ }
+ }
+ if (msg->flags & I2C_M_RD)
+ return -4;
+ else
+ return -2;
+}
+
+/**
+ * i2c_transfer: - Transfer one byte over the i2c bus
+ *
+ * This function can tranfer a byte over the i2c bus in both directions.
+ * It is used by the public API functions.
+ *
+ * @return: 0: transfer successful
+ * -1: transfer fail
+ * -2: transmit timeout
+ * -3: ACK missing
+ * -4: receive timeout
+ * -5: controller not ready
+ */
+int i2c_transfer(struct i2c_msg *msg)
+{
+ int ret = 0;
+ int timeout_count = 10000;
+ int len = msg->len;
+
+ if (!(bfin_read_TWI_CONTROL() & TWI_ENA)) {
+ ret = -5;
+ goto transfer_error;
+ }
+
+ while (bfin_read_TWI_MASTER_STAT() & BUSBUSY)
+ continue;
+
+ /* Set Transmit device address */
+ bfin_write_TWI_MASTER_ADDR(msg->addr);
+
+ /*
+ * FIFO Initiation.
+ * Data in FIFO should be discarded before start a new operation.
+ */
+ bfin_write_TWI_FIFO_CTL(0x3);
+ SSYNC();
+ bfin_write_TWI_FIFO_CTL(0);
+ SSYNC();
+
+ if (!(msg->flags & I2C_M_RD)) {
+ /* Transmit first data */
+ if (msg->len > 0) {
+ PRINTD("1 in i2c_transfer: buf=%d, len=%d\n", *msg->buf,
+ len);
+ bfin_write_TWI_XMT_DATA8(*(msg->buf++));
+ msg->len--;
+ SSYNC();
+ }
+ }
+
+ /* clear int stat */
+ bfin_write_TWI_INT_STAT(MERR | MCOMP | XMTSERV | RCVSERV);
+
+ /* Interrupt mask . Enable XMT, RCV interrupt */
+ bfin_write_TWI_INT_MASK(MCOMP | MERR |
+ ((msg->flags & I2C_M_RD) ? RCVSERV : XMTSERV));
+ SSYNC();
+
+ if (len > 0 && len <= 255)
+ bfin_write_TWI_MASTER_CTL((len << 6));
+ else if (msg->len > 255) {
+ bfin_write_TWI_MASTER_CTL((0xff << 6));
+ msg->flags &= I2C_M_STOP;
+ } else
+ bfin_write_TWI_MASTER_CTL(0);
+
+ /* Master enable */
+ bfin_write_TWI_MASTER_CTL(bfin_read_TWI_MASTER_CTL() | MEN |
+ ((msg->flags & I2C_M_RD)
+ ? MDIR : 0) | ((CONFIG_TWICLK_KHZ >
+ 100) ? FAST : 0));
+ SSYNC();
+
+ ret = wait_for_completion(msg, timeout_count);
+ PRINTD("3 in i2c_transfer: ret=%d\n", ret);
+
+ transfer_error:
+ switch (ret) {
+ case 1:
+ PRINTD(("i2c_transfer: error: transfer fail\n"));
+ break;
+ case 2:
+ PRINTD(("i2c_transfer: error: transmit timeout\n"));
+ break;
+ case 3:
+ PRINTD(("i2c_transfer: error: ACK missing\n"));
+ break;
+ case 4:
+ PRINTD(("i2c_transfer: error: receive timeout\n"));
+ break;
+ case 5:
+ PRINTD(("i2c_transfer: error: controller not ready\n"));
+ i2c_reset();
+ break;
+ default:
+ break;
+ }
+ return ret;
+
+}
+
+/* ---------------------------------------------------------------------*/
+/* API Functions */
+/* ---------------------------------------------------------------------*/
+
+void i2c_init(int speed, int slaveaddr)
+{
+ i2c_reset();
+}
+
+/**
+ * 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(uchar chip)
+{
+ struct i2c_msg msg;
+ u8 probebuf;
+
+ i2c_reset();
+
+ probebuf = 0;
+ msg.addr = chip;
+ msg.flags = 0;
+ msg.len = 1;
+ msg.buf = &probebuf;
+ if (i2c_transfer(&msg))
+ return -1;
+
+ msg.addr = chip;
+ msg.flags = I2C_M_RD;
+ msg.len = 1;
+ msg.buf = &probebuf;
+ if (i2c_transfer(&msg))
+ return -1;
+
+ return 0;
+}
+
+/**
+ * i2c_read: - Read multiple bytes from an i2c device
+ *
+ * chip: I2C chip address, range 0..127
+ * addr: Memory (register) address within the chip
+ * alen: Number of bytes to use for addr (typically 1, 2 for larger
+ * memories, 0 for register type devices with only one
+ * register)
+ * buffer: Where to read/write the data
+ * len: How many bytes to read/write
+ *
+ * Returns: 0 on success, not 0 on failure
+ */
+
+int i2c_read(uchar chip, uint addr, int alen, uchar * buffer, int len)
+{
+ struct i2c_msg msg;
+ u8 addr_bytes[3]; /* lowest...highest byte of data address */
+
+ PRINTD("i2c_read: chip=0x%x, addr=0x%x, alen=0x%x, len=0x%x\n", chip,
+ addr, alen, len);
+
+ if (alen > 0) {
+ addr_bytes[0] = (u8) ((addr >> 0) & 0x000000FF);
+ addr_bytes[1] = (u8) ((addr >> 8) & 0x000000FF);
+ addr_bytes[2] = (u8) ((addr >> 16) & 0x000000FF);
+ msg.addr = chip;
+ msg.flags = 0;
+ msg.len = alen;
+ msg.buf = addr_bytes;
+ if (i2c_transfer(&msg))
+ return -1;
+ }
+
+ /* start read sequence */
+ PRINTD(("i2c_read: start read sequence\n"));
+ msg.addr = chip;
+ msg.flags = I2C_M_RD;
+ msg.len = len;
+ msg.buf = buffer;
+ if (i2c_transfer(&msg))
+ return -1;
+
+ return 0;
+}
+
+/**
+ * i2c_write: - Write multiple bytes to an i2c device
+ *
+ * chip: I2C chip address, range 0..127
+ * addr: Memory (register) address within the chip
+ * alen: Number of bytes to use for addr (typically 1, 2 for larger
+ * memories, 0 for register type devices with only one
+ * register)
+ * buffer: Where to read/write the data
+ * len: How many bytes to read/write
+ *
+ * Returns: 0 on success, not 0 on failure
+ */
+
+int i2c_write(uchar chip, uint addr, int alen, uchar * buffer, int len)
+{
+ struct i2c_msg msg;
+ u8 addr_bytes[3]; /* lowest...highest byte of data address */
+
+ PRINTD
+ ("i2c_write: chip=0x%x, addr=0x%x, alen=0x%x, len=0x%x, buf0=0x%x\n",
+ chip, addr, alen, len, buffer[0]);
+
+ /* chip address write */
+ if (alen > 0) {
+ addr_bytes[0] = (u8) ((addr >> 0) & 0x000000FF);
+ addr_bytes[1] = (u8) ((addr >> 8) & 0x000000FF);
+ addr_bytes[2] = (u8) ((addr >> 16) & 0x000000FF);
+ msg.addr = chip;
+ msg.flags = 0;
+ msg.len = alen;
+ msg.buf = addr_bytes;
+ if (i2c_transfer(&msg))
+ return -1;
+ }
+
+ /* start read sequence */
+ PRINTD(("i2c_write: start write sequence\n"));
+ msg.addr = chip;
+ msg.flags = 0;
+ msg.len = len;
+ msg.buf = buffer;
+ if (i2c_transfer(&msg))
+ return -1;
+
+ return 0;
+
+}
+
+uchar i2c_reg_read(uchar chip, uchar reg)
+{
+ uchar buf;
+
+ PRINTD("i2c_reg_read: chip=0x%02x, reg=0x%02x\n", chip, reg);
+ i2c_read(chip, reg, 0, &buf, 1);
+ return (buf);
+}
+
+void i2c_reg_write(uchar chip, uchar reg, uchar val)
+{
+ PRINTD("i2c_reg_write: chip=0x%02x, reg=0x%02x, val=0x%02x\n", chip,
+ reg, val);
+ i2c_write(chip, reg, 0, &val, 1);
+}
+
+#endif /* CONFIG_HARD_I2C */
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