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-rw-r--r--drivers/i2c/mvtwsi.c127
1 files changed, 85 insertions, 42 deletions
diff --git a/drivers/i2c/mvtwsi.c b/drivers/i2c/mvtwsi.c
index 8552fba..f060cd1 100644
--- a/drivers/i2c/mvtwsi.c
+++ b/drivers/i2c/mvtwsi.c
@@ -12,6 +12,7 @@
#include <i2c.h>
#include <asm/errno.h>
#include <asm/io.h>
+#include <linux/compat.h>
#ifdef CONFIG_DM_I2C
#include <dm.h>
#endif
@@ -78,6 +79,8 @@ struct mvtwsi_i2c_dev {
u8 slaveadd;
/* The configured I2C speed in Hz */
uint speed;
+ /* The current length of a clock period (depending on speed) */
+ uint tick;
};
#endif /* CONFIG_DM_I2C */
@@ -154,7 +157,15 @@ enum mvtwsi_ack_flags {
MVTWSI_READ_ACK = 1,
};
+inline uint calc_tick(uint speed)
+{
+ /* One tick = the duration of a period at the specified speed in ns (we
+ * add 100 ns to be on the safe side) */
+ return (1000000000u / speed) + 100;
+}
+
#ifndef CONFIG_DM_I2C
+
/*
* MVTWSI controller base
*/
@@ -230,7 +241,8 @@ inline uint mvtwsi_error(uint ec, uint lc, uint ls, uint es)
* Wait for IFLG to raise, or return 'timeout.' Then, if the status is as
* expected, return 0 (ok) or 'wrong status' otherwise.
*/
-static int twsi_wait(struct mvtwsi_registers *twsi, int expected_status)
+static int twsi_wait(struct mvtwsi_registers *twsi, int expected_status,
+ uint tick)
{
int control, status;
int timeout = 1000;
@@ -246,7 +258,7 @@ static int twsi_wait(struct mvtwsi_registers *twsi, int expected_status)
MVTWSI_ERROR_WRONG_STATUS,
control, status, expected_status);
}
- udelay(10); /* One clock cycle at 100 kHz */
+ ndelay(tick); /* One clock cycle */
} while (timeout--);
status = readl(&twsi->status);
return mvtwsi_error(MVTWSI_ERROR_TIMEOUT, control, status,
@@ -257,20 +269,21 @@ static int twsi_wait(struct mvtwsi_registers *twsi, int expected_status)
* Assert the START condition, either in a single I2C transaction
* or inside back-to-back ones (repeated starts).
*/
-static int twsi_start(struct mvtwsi_registers *twsi, int expected_status)
+static int twsi_start(struct mvtwsi_registers *twsi, int expected_status,
+ uint tick)
{
/* Assert START */
writel(MVTWSI_CONTROL_TWSIEN | MVTWSI_CONTROL_START |
MVTWSI_CONTROL_CLEAR_IFLG, &twsi->control);
/* Wait for controller to process START */
- return twsi_wait(twsi, expected_status);
+ return twsi_wait(twsi, expected_status, tick);
}
/*
* Send a byte (i2c address or data).
*/
static int twsi_send(struct mvtwsi_registers *twsi, u8 byte,
- int expected_status)
+ int expected_status, uint tick)
{
/* Write byte to data register for sending */
writel(byte, &twsi->data);
@@ -278,13 +291,14 @@ static int twsi_send(struct mvtwsi_registers *twsi, u8 byte,
writel(MVTWSI_CONTROL_TWSIEN | MVTWSI_CONTROL_CLEAR_IFLG,
&twsi->control);
/* Wait for controller to receive byte, and check ACK */
- return twsi_wait(twsi, expected_status);
+ return twsi_wait(twsi, expected_status, tick);
}
/*
* Receive a byte.
*/
-static int twsi_recv(struct mvtwsi_registers *twsi, u8 *byte, int ack_flag)
+static int twsi_recv(struct mvtwsi_registers *twsi, u8 *byte, int ack_flag,
+ uint tick)
{
int expected_status, status, control;
@@ -296,7 +310,7 @@ static int twsi_recv(struct mvtwsi_registers *twsi, u8 *byte, int ack_flag)
control |= ack_flag == MVTWSI_READ_ACK ? MVTWSI_CONTROL_ACK : 0;
writel(control | MVTWSI_CONTROL_CLEAR_IFLG, &twsi->control);
/* Wait for controller to receive byte, and assert ACK or NAK */
- status = twsi_wait(twsi, expected_status);
+ status = twsi_wait(twsi, expected_status, tick);
/* If we did receive the expected byte, store it */
if (status == 0)
*byte = readl(&twsi->data);
@@ -307,7 +321,7 @@ static int twsi_recv(struct mvtwsi_registers *twsi, u8 *byte, int ack_flag)
* Assert the STOP condition.
* This is also used to force the bus back to idle (SDA = SCL = 1).
*/
-static int twsi_stop(struct mvtwsi_registers *twsi)
+static int twsi_stop(struct mvtwsi_registers *twsi, uint tick)
{
int control, stop_status;
int status = 0;
@@ -321,7 +335,7 @@ static int twsi_stop(struct mvtwsi_registers *twsi)
stop_status = readl(&twsi->status);
if (stop_status == MVTWSI_STATUS_IDLE)
break;
- udelay(10); /* One clock cycle at 100 kHz */
+ ndelay(tick); /* One clock cycle */
} while (timeout--);
control = readl(&twsi->control);
if (stop_status != MVTWSI_STATUS_IDLE)
@@ -376,21 +390,32 @@ static uint __twsi_i2c_set_bus_speed(struct mvtwsi_registers *twsi,
}
}
writel(baud, &twsi->baudrate);
- return 0;
+
+ /* Wait for controller for one tick */
+#ifdef CONFIG_DM_I2C
+ ndelay(calc_tick(highest_speed));
+#else
+ ndelay(10000);
+#endif
+ return highest_speed;
}
static void __twsi_i2c_init(struct mvtwsi_registers *twsi, int speed,
- int slaveadd)
+ int slaveadd, uint *actual_speed)
{
/* Reset controller */
twsi_reset(twsi);
/* Set speed */
- __twsi_i2c_set_bus_speed(twsi, speed);
+ *actual_speed = __twsi_i2c_set_bus_speed(twsi, speed);
/* Set slave address; even though we don't use it */
writel(slaveadd, &twsi->slave_address);
writel(0, &twsi->xtnd_slave_addr);
/* Assert STOP, but don't care for the result */
- (void) twsi_stop(twsi);
+#ifdef CONFIG_DM_I2C
+ (void) twsi_stop(twsi, calc_tick(*actual_speed));
+#else
+ (void) twsi_stop(twsi, 10000);
+#endif
}
/*
@@ -398,7 +423,7 @@ static void __twsi_i2c_init(struct mvtwsi_registers *twsi, int speed,
* Expected address status will derive from direction bit (bit 0) in addr.
*/
static int i2c_begin(struct mvtwsi_registers *twsi, int expected_start_status,
- u8 addr)
+ u8 addr, uint tick)
{
int status, expected_addr_status;
@@ -409,10 +434,10 @@ static int i2c_begin(struct mvtwsi_registers *twsi, int expected_start_status,
else /* Writing */
expected_addr_status = MVTWSI_STATUS_ADDR_W_ACK;
/* Assert START */
- status = twsi_start(twsi, expected_start_status);
+ status = twsi_start(twsi, expected_start_status, tick);
/* Send out the address if the start went well */
if (status == 0)
- status = twsi_send(twsi, addr, expected_addr_status);
+ status = twsi_send(twsi, addr, expected_addr_status, tick);
/* Return 0, or the status of the first failure */
return status;
}
@@ -420,18 +445,19 @@ static int i2c_begin(struct mvtwsi_registers *twsi, int expected_start_status,
/*
* Begin read, nak data byte, end.
*/
-static int __twsi_i2c_probe_chip(struct mvtwsi_registers *twsi, uchar chip)
+static int __twsi_i2c_probe_chip(struct mvtwsi_registers *twsi, uchar chip,
+ uint tick)
{
u8 dummy_byte;
int status;
/* Begin i2c read */
- status = i2c_begin(twsi, MVTWSI_STATUS_START, (chip << 1) | 1);
+ status = i2c_begin(twsi, MVTWSI_STATUS_START, (chip << 1) | 1, tick);
/* Dummy read was accepted: receive byte, but NAK it. */
if (status == 0)
- status = twsi_recv(twsi, &dummy_byte, MVTWSI_READ_NAK);
+ status = twsi_recv(twsi, &dummy_byte, MVTWSI_READ_NAK, tick);
/* Stop transaction */
- twsi_stop(twsi);
+ twsi_stop(twsi, tick);
/* Return 0, or the status of the first failure */
return status;
}
@@ -445,7 +471,8 @@ static int __twsi_i2c_probe_chip(struct mvtwsi_registers *twsi, uchar chip)
* will be a repeated start without a preceding stop.
*/
static int __twsi_i2c_read(struct mvtwsi_registers *twsi, uchar chip,
- u8 *addr, int alen, uchar *data, int length)
+ u8 *addr, int alen, uchar *data, int length,
+ uint tick)
{
int status = 0;
int stop_status;
@@ -453,25 +480,25 @@ static int __twsi_i2c_read(struct mvtwsi_registers *twsi, uchar chip,
if (alen > 0) {
/* Begin i2c write to send the address bytes */
- status = i2c_begin(twsi, expected_start, (chip << 1));
+ status = i2c_begin(twsi, expected_start, (chip << 1), tick);
/* Send address bytes */
while ((status == 0) && alen--)
status = twsi_send(twsi, *(addr++),
- MVTWSI_STATUS_DATA_W_ACK);
+ MVTWSI_STATUS_DATA_W_ACK, tick);
/* Send repeated STARTs after the initial START */
expected_start = MVTWSI_STATUS_REPEATED_START;
}
/* Begin i2c read to receive data bytes */
if (status == 0)
- status = i2c_begin(twsi, expected_start, (chip << 1) | 1);
+ status = i2c_begin(twsi, expected_start, (chip << 1) | 1, tick);
/* Receive actual data bytes; set NAK if we if we have nothing more to
* read */
while ((status == 0) && length--)
status = twsi_recv(twsi, data++,
length > 0 ?
- MVTWSI_READ_ACK : MVTWSI_READ_NAK);
+ MVTWSI_READ_ACK : MVTWSI_READ_NAK, tick);
/* Stop transaction */
- stop_status = twsi_stop(twsi);
+ stop_status = twsi_stop(twsi, tick);
/* Return 0, or the status of the first failure */
return status != 0 ? status : stop_status;
}
@@ -480,21 +507,24 @@ static int __twsi_i2c_read(struct mvtwsi_registers *twsi, uchar chip,
* Begin write, send address byte(s), send data bytes, end.
*/
static int __twsi_i2c_write(struct mvtwsi_registers *twsi, uchar chip,
- u8 *addr, int alen, uchar *data, int length)
+ u8 *addr, int alen, uchar *data, int length,
+ uint tick)
{
int status, stop_status;
/* Begin i2c write to send first the address bytes, then the
* data bytes */
- status = i2c_begin(twsi, MVTWSI_STATUS_START, (chip << 1));
+ status = i2c_begin(twsi, MVTWSI_STATUS_START, (chip << 1), tick);
/* Send address bytes */
while ((status == 0) && (alen-- > 0))
- status = twsi_send(twsi, *(addr++), MVTWSI_STATUS_DATA_W_ACK);
+ status = twsi_send(twsi, *(addr++), MVTWSI_STATUS_DATA_W_ACK,
+ tick);
/* Send data bytes */
while ((status == 0) && (length-- > 0))
- status = twsi_send(twsi, *(data++), MVTWSI_STATUS_DATA_W_ACK);
+ status = twsi_send(twsi, *(data++), MVTWSI_STATUS_DATA_W_ACK,
+ tick);
/* Stop transaction */
- stop_status = twsi_stop(twsi);
+ stop_status = twsi_stop(twsi, tick);
/* Return 0, or the status of the first failure */
return status != 0 ? status : stop_status;
}
@@ -504,20 +534,21 @@ static void twsi_i2c_init(struct i2c_adapter *adap, int speed,
int slaveadd)
{
struct mvtwsi_registers *twsi = twsi_get_base(adap);
- __twsi_i2c_init(twsi, speed, slaveadd);
+ __twsi_i2c_init(twsi, speed, slaveadd, NULL);
}
static uint twsi_i2c_set_bus_speed(struct i2c_adapter *adap,
uint requested_speed)
{
struct mvtwsi_registers *twsi = twsi_get_base(adap);
- return __twsi_i2c_set_bus_speed(twsi, requested_speed);
+ __twsi_i2c_set_bus_speed(twsi, requested_speed);
+ return 0;
}
static int twsi_i2c_probe(struct i2c_adapter *adap, uchar chip)
{
struct mvtwsi_registers *twsi = twsi_get_base(adap);
- return __twsi_i2c_probe_chip(twsi, chip);
+ return __twsi_i2c_probe_chip(twsi, chip, 10000);
}
static int twsi_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr,
@@ -531,7 +562,8 @@ static int twsi_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr,
addr_bytes[2] = (addr >> 16) & 0xFF;
addr_bytes[3] = (addr >> 24) & 0xFF;
- return __twsi_i2c_read(twsi, chip, addr_bytes, alen, data, length);
+ return __twsi_i2c_read(twsi, chip, addr_bytes, alen, data, length,
+ 10000);
}
static int twsi_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr,
@@ -545,7 +577,8 @@ static int twsi_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr,
addr_bytes[2] = (addr >> 16) & 0xFF;
addr_bytes[3] = (addr >> 24) & 0xFF;
- return __twsi_i2c_write(twsi, chip, addr_bytes, alen, data, length);
+ return __twsi_i2c_write(twsi, chip, addr_bytes, alen, data, length,
+ 10000);
}
#ifdef CONFIG_I2C_MVTWSI_BASE0
@@ -595,13 +628,17 @@ static int mvtwsi_i2c_probe_chip(struct udevice *bus, u32 chip_addr,
u32 chip_flags)
{
struct mvtwsi_i2c_dev *dev = dev_get_priv(bus);
- return __twsi_i2c_probe_chip(dev->base, chip_addr);
+ return __twsi_i2c_probe_chip(dev->base, chip_addr, dev->tick);
}
static int mvtwsi_i2c_set_bus_speed(struct udevice *bus, uint speed)
{
struct mvtwsi_i2c_dev *dev = dev_get_priv(bus);
- return __twsi_i2c_set_bus_speed(dev->base, speed);
+
+ dev->speed = __twsi_i2c_set_bus_speed(dev->base, speed);
+ dev->tick = calc_tick(dev->speed);
+
+ return 0;
}
static int mvtwsi_i2c_ofdata_to_platdata(struct udevice *bus)
@@ -625,7 +662,11 @@ static int mvtwsi_i2c_ofdata_to_platdata(struct udevice *bus)
static int mvtwsi_i2c_probe(struct udevice *bus)
{
struct mvtwsi_i2c_dev *dev = dev_get_priv(bus);
- __twsi_i2c_init(dev->base, dev->speed, dev->slaveadd);
+ uint actual_speed;
+
+ __twsi_i2c_init(dev->base, dev->speed, dev->slaveadd, &actual_speed);
+ dev->speed = actual_speed;
+ dev->tick = calc_tick(dev->speed);
return 0;
}
@@ -648,10 +689,12 @@ static int mvtwsi_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs)
if (dmsg->flags & I2C_M_RD)
return __twsi_i2c_read(dev->base, dmsg->addr, omsg->buf,
- omsg->len, dmsg->buf, dmsg->len);
+ omsg->len, dmsg->buf, dmsg->len,
+ dev->tick);
else
return __twsi_i2c_write(dev->base, dmsg->addr, omsg->buf,
- omsg->len, dmsg->buf, dmsg->len);
+ omsg->len, dmsg->buf, dmsg->len,
+ dev->tick);
}
static const struct dm_i2c_ops mvtwsi_i2c_ops = {
generated by cgit v1.1 at 2024-12-26 04:37:56 +0000