[U-Boot] [PATCH v2] Blackfin: TWI/I2C: implement multibus support
Mike Frysinger
vapier at gentoo.org
Wed May 5 09:20:30 CEST 2010
In order to do this cleanly, the register accesses have to be converted to
a C struct (base pointer), so do that in the process.
Signed-off-by: Mike Frysinger <vapier at gentoo.org>
---
v2
- extend changelog
drivers/i2c/bfin-twi_i2c.c | 169 ++++++++++++++++++++++++++++----------------
1 files changed, 108 insertions(+), 61 deletions(-)
diff --git a/drivers/i2c/bfin-twi_i2c.c b/drivers/i2c/bfin-twi_i2c.c
index 73a78d2..b3a04d3 100644
--- a/drivers/i2c/bfin-twi_i2c.c
+++ b/drivers/i2c/bfin-twi_i2c.c
@@ -1,7 +1,7 @@
/*
* i2c.c - driver for Blackfin on-chip TWI/I2C
*
- * Copyright (c) 2006-2008 Analog Devices Inc.
+ * Copyright (c) 2006-2010 Analog Devices Inc.
*
* Licensed under the GPL-2 or later.
*/
@@ -12,6 +12,35 @@
#include <asm/blackfin.h>
#include <asm/mach-common/bits/twi.h>
+/* Every register is 32bit aligned, but only 16bits in size */
+#define ureg(name) u16 name; u16 __pad_##name;
+struct twi_regs {
+ ureg(clkdiv);
+ ureg(control);
+ ureg(slave_ctl);
+ ureg(slave_stat);
+ ureg(slave_addr);
+ ureg(master_ctl);
+ ureg(master_stat);
+ ureg(master_addr);
+ ureg(int_stat);
+ ureg(int_mask);
+ ureg(fifo_ctl);
+ ureg(fifo_stat);
+ char __pad[0x50];
+ ureg(xmt_data8);
+ ureg(xmt_data16);
+ ureg(rcv_data8);
+ ureg(rcv_data16);
+};
+#undef ureg
+
+/* U-Boot I2C framework allows only one active device at a time. */
+#ifdef TWI_CLKDIV
+#define TWI0_CLKDIV TWI_CLKDIV
+#endif
+static volatile struct twi_regs *twi = (void *)TWI0_CLKDIV;
+
#ifdef DEBUG
# define dmemset(s, c, n) memset(s, c, n)
#else
@@ -19,29 +48,10 @@
#endif
#define debugi(fmt, args...) \
debug( \
- "MSTAT:0x%03x FSTAT:0x%x ISTAT:0x%02x\t" \
- "%-20s:%-3i: " fmt "\n", \
- bfin_read_TWI_MASTER_STAT(), bfin_read_TWI_FIFO_STAT(), bfin_read_TWI_INT_STAT(), \
+ "MSTAT:0x%03x FSTAT:0x%x ISTAT:0x%02x\t%-20s:%-3i: " fmt "\n", \
+ twi->master_stat, twi->fifo_stat, twi->int_stat, \
__func__, __LINE__, ## args)
-#ifdef TWI0_CLKDIV
-#define bfin_write_TWI_CLKDIV(val) bfin_write_TWI0_CLKDIV(val)
-#define bfin_read_TWI_CLKDIV(val) bfin_read_TWI0_CLKDIV(val)
-#define bfin_write_TWI_CONTROL(val) bfin_write_TWI0_CONTROL(val)
-#define bfin_read_TWI_CONTROL(val) bfin_read_TWI0_CONTROL(val)
-#define bfin_write_TWI_MASTER_ADDR(val) bfin_write_TWI0_MASTER_ADDR(val)
-#define bfin_write_TWI_XMT_DATA8(val) bfin_write_TWI0_XMT_DATA8(val)
-#define bfin_read_TWI_RCV_DATA8() bfin_read_TWI0_RCV_DATA8()
-#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_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_CTL() bfin_read_TWI0_MASTER_CTL()
-#define bfin_write_TWI_MASTER_CTL(val) bfin_write_TWI0_MASTER_CTL(val)
-#define bfin_write_TWI_INT_MASK(val) bfin_write_TWI0_INT_MASK(val)
-#define bfin_write_TWI_FIFO_CTL(val) bfin_write_TWI0_FIFO_CTL(val)
-#endif
-
#ifdef CONFIG_TWICLK_KHZ
# error do not define CONFIG_TWICLK_KHZ ... use CONFIG_SYS_I2C_SPEED
#endif
@@ -87,49 +97,48 @@ static int wait_for_completion(struct i2c_msg *msg)
ulong timebase = get_timer(0);
do {
- int_stat = bfin_read_TWI_INT_STAT();
+ int_stat = twi->int_stat;
if (int_stat & XMTSERV) {
debugi("processing XMTSERV");
- bfin_write_TWI_INT_STAT(XMTSERV);
+ twi->int_stat = XMTSERV;
SSYNC();
if (msg->alen) {
- bfin_write_TWI_XMT_DATA8(*(msg->abuf++));
+ twi->xmt_data8 = *(msg->abuf++);
--msg->alen;
} else if (!(msg->flags & I2C_M_COMBO) && msg->len) {
- bfin_write_TWI_XMT_DATA8(*(msg->buf++));
+ twi->xmt_data8 = *(msg->buf++);
--msg->len;
} else {
- bfin_write_TWI_MASTER_CTL(bfin_read_TWI_MASTER_CTL() |
- (msg->flags & I2C_M_COMBO ? RSTART | MDIR : STOP));
+ twi->master_ctl |= (msg->flags & I2C_M_COMBO) ? RSTART | MDIR : STOP;
SSYNC();
}
}
if (int_stat & RCVSERV) {
debugi("processing RCVSERV");
- bfin_write_TWI_INT_STAT(RCVSERV);
+ twi->int_stat = RCVSERV;
SSYNC();
if (msg->len) {
- *(msg->buf++) = bfin_read_TWI_RCV_DATA8();
+ *(msg->buf++) = twi->rcv_data8;
--msg->len;
} else if (msg->flags & I2C_M_STOP) {
- bfin_write_TWI_MASTER_CTL(bfin_read_TWI_MASTER_CTL() | STOP);
+ twi->master_ctl |= STOP;
SSYNC();
}
}
if (int_stat & MERR) {
debugi("processing MERR");
- bfin_write_TWI_INT_STAT(MERR);
+ twi->int_stat = MERR;
SSYNC();
return msg->len;
}
if (int_stat & MCOMP) {
debugi("processing MCOMP");
- bfin_write_TWI_INT_STAT(MCOMP);
+ twi->int_stat = MCOMP;
SSYNC();
if (msg->flags & I2C_M_COMBO && msg->len) {
- bfin_write_TWI_MASTER_CTL((bfin_read_TWI_MASTER_CTL() & ~RSTART) |
- (min(msg->len, 0xff) << 6) | MEN | MDIR);
+ twi->master_ctl = (twi->master_ctl & ~RSTART) |
+ (min(msg->len, 0xff) << 6) | MEN | MDIR;
SSYNC();
} else
break;
@@ -172,55 +181,54 @@ static int i2c_transfer(uchar chip, uint addr, int alen, uchar *buffer, int len,
chip, addr, alen, buffer[0], len, flags, (flags & I2C_M_READ ? "rd" : "wr"));
/* wait for things to settle */
- while (bfin_read_TWI_MASTER_STAT() & BUSBUSY)
+ while (twi->master_stat & BUSBUSY)
if (ctrlc())
return 1;
/* Set Transmit device address */
- bfin_write_TWI_MASTER_ADDR(chip);
+ twi->master_addr = chip;
/* Clear the FIFO before starting things */
- bfin_write_TWI_FIFO_CTL(XMTFLUSH | RCVFLUSH);
+ twi->fifo_ctl = XMTFLUSH | RCVFLUSH;
SSYNC();
- bfin_write_TWI_FIFO_CTL(0);
+ twi->fifo_ctl = 0;
SSYNC();
/* prime the pump */
if (msg.alen) {
len = (msg.flags & I2C_M_COMBO) ? msg.alen : msg.alen + len;
debugi("first byte=0x%02x", *msg.abuf);
- bfin_write_TWI_XMT_DATA8(*(msg.abuf++));
+ twi->xmt_data8 = *(msg.abuf++);
--msg.alen;
} else if (!(msg.flags & I2C_M_READ) && msg.len) {
debugi("first byte=0x%02x", *msg.buf);
- bfin_write_TWI_XMT_DATA8(*(msg.buf++));
+ twi->xmt_data8 = *(msg.buf++);
--msg.len;
}
/* clear int stat */
- bfin_write_TWI_MASTER_STAT(-1);
- bfin_write_TWI_INT_STAT(-1);
- bfin_write_TWI_INT_MASK(0);
+ twi->master_stat = -1;
+ twi->int_stat = -1;
+ twi->int_mask = 0;
SSYNC();
/* Master enable */
- bfin_write_TWI_MASTER_CTL(
- (bfin_read_TWI_MASTER_CTL() & FAST) |
+ twi->master_ctl =
+ (twi->master_ctl & FAST) |
(min(len, 0xff) << 6) | MEN |
- ((msg.flags & I2C_M_READ) ? MDIR : 0)
- );
+ ((msg.flags & I2C_M_READ) ? MDIR : 0);
SSYNC();
- debugi("CTL=0x%04x", bfin_read_TWI_MASTER_CTL());
+ debugi("CTL=0x%04x", twi->master_ctl);
/* process the rest */
ret = wait_for_completion(&msg);
debugi("ret=%d", ret);
if (ret) {
- bfin_write_TWI_MASTER_CTL(bfin_read_TWI_MASTER_CTL() & ~MEN);
- bfin_write_TWI_CONTROL(bfin_read_TWI_CONTROL() & ~TWI_ENA);
+ twi->master_ctl &= ~MEN;
+ twi->control &= ~TWI_ENA;
SSYNC();
- bfin_write_TWI_CONTROL(bfin_read_TWI_CONTROL() | TWI_ENA);
+ twi->control |= TWI_ENA;
SSYNC();
}
@@ -238,10 +246,10 @@ int i2c_set_bus_speed(unsigned int speed)
/* Set TWI interface clock */
if (clkdiv < I2C_DUTY_MAX || clkdiv > I2C_DUTY_MIN)
return -1;
- bfin_write_TWI_CLKDIV((clkdiv << 8) | (clkdiv & 0xff));
+ twi->clkdiv = (clkdiv << 8) | (clkdiv & 0xff);
/* Don't turn it on */
- bfin_write_TWI_MASTER_CTL(speed > 100000 ? FAST : 0);
+ twi->master_ctl = (speed > 100000 ? FAST : 0);
return 0;
}
@@ -253,7 +261,7 @@ int i2c_set_bus_speed(unsigned int speed)
unsigned int i2c_get_bus_speed(void)
{
/* 10 MHz / (2 * CLKDIV) -> 5 MHz / CLKDIV */
- return 5000000 / (bfin_read_TWI_CLKDIV() & 0xff);
+ return 5000000 / (twi->clkdiv & 0xff);
}
/**
@@ -269,24 +277,23 @@ void i2c_init(int speed, int slaveaddr)
uint8_t prescale = ((get_sclk() / 1024 / 1024 + 5) / 10) & 0x7F;
/* Set TWI internal clock as 10MHz */
- bfin_write_TWI_CONTROL(prescale);
+ twi->control = prescale;
/* Set TWI interface clock as specified */
i2c_set_bus_speed(speed);
/* Enable it */
- bfin_write_TWI_CONTROL(TWI_ENA | prescale);
+ twi->control = TWI_ENA | prescale;
SSYNC();
- debugi("CONTROL:0x%04x CLKDIV:0x%04x",
- bfin_read_TWI_CONTROL(), bfin_read_TWI_CLKDIV());
+ debugi("CONTROL:0x%04x CLKDIV:0x%04x", twi->control, twi->clkdiv);
#if CONFIG_SYS_I2C_SLAVE
# error I2C slave support not tested/supported
/* If they want us as a slave, do it */
if (slaveaddr) {
- bfin_write_TWI_SLAVE_ADDR(slaveaddr);
- bfin_write_TWI_SLAVE_CTL(SEN);
+ twi->slave_addr = slaveaddr;
+ twi->slave_ctl = SEN;
}
#endif
}
@@ -329,3 +336,43 @@ int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
{
return i2c_transfer(chip, addr, alen, buffer, len, 0);
}
+
+/**
+ * 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)
+{
+ switch (bus) {
+#if CONFIG_SYS_MAX_I2C_BUS > 0
+ case 0: twi = (void *)TWI0_CLKDIV; return 0;
+#endif
+#if CONFIG_SYS_MAX_I2C_BUS > 1
+ case 1: twi = (void *)TWI1_CLKDIV; return 0;
+#endif
+#if CONFIG_SYS_MAX_I2C_BUS > 2
+ case 2: twi = (void *)TWI2_CLKDIV; return 0;
+#endif
+ default: return -1;
+ }
+}
+
+/**
+ * i2c_get_bus_num - returns index of active I2C bus
+ */
+unsigned int i2c_get_bus_num(void)
+{
+ switch ((unsigned long)twi) {
+#if CONFIG_SYS_MAX_I2C_BUS > 0
+ case TWI0_CLKDIV: return 0;
+#endif
+#if CONFIG_SYS_MAX_I2C_BUS > 1
+ case TWI1_CLKDIV: return 1;
+#endif
+#if CONFIG_SYS_MAX_I2C_BUS > 2
+ case TWI2_CLKDIV: return 2;
+#endif
+ default: return -1;
+ }
+}
--
1.7.1
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