mirror of
https://github.com/u-boot/u-boot.git
synced 2025-04-27 07:51:38 +00:00
dm: i2c-gpio: rework gpio get/set functions
This patch reworks i2c-gpio to make it easier to switch out the implementation of the sda/scl get/set functions. This is in preparation for a patch to conditionally implement clock stretching support. Signed-off-by: Michael Auchter <michael.auchter@ni.com> Cc: Heiko Schocher <hs@denx.de> Reviewed-by: Heiko Schocher <hs@denx.de>
This commit is contained in:
Michael Auchter
Heiko Schocher
parent
092d9ea26c
commit
7383edc2fb
1 changed files with 64 additions and 69 deletions
|
|
@ -32,23 +32,32 @@ struct i2c_gpio_bus {
|
|||
int udelay;
|
||||
/* sda, scl */
|
||||
struct gpio_desc gpios[PIN_COUNT];
|
||||
|
||||
int (*get_sda)(struct i2c_gpio_bus *bus);
|
||||
void (*set_sda)(struct i2c_gpio_bus *bus, int bit);
|
||||
void (*set_scl)(struct i2c_gpio_bus *bus, int bit);
|
||||
};
|
||||
|
||||
static int i2c_gpio_sda_get(struct gpio_desc *sda)
|
||||
static int i2c_gpio_sda_get(struct i2c_gpio_bus *bus)
|
||||
{
|
||||
struct gpio_desc *sda = &bus->gpios[PIN_SDA];
|
||||
|
||||
return dm_gpio_get_value(sda);
|
||||
}
|
||||
|
||||
static void i2c_gpio_sda_set(struct gpio_desc *sda, int bit)
|
||||
static void i2c_gpio_sda_set(struct i2c_gpio_bus *bus, int bit)
|
||||
{
|
||||
struct gpio_desc *sda = &bus->gpios[PIN_SDA];
|
||||
|
||||
if (bit)
|
||||
dm_gpio_set_dir_flags(sda, GPIOD_IS_IN);
|
||||
else
|
||||
dm_gpio_set_dir_flags(sda, GPIOD_IS_OUT);
|
||||
}
|
||||
|
||||
static void i2c_gpio_scl_set(struct gpio_desc *scl, int bit)
|
||||
static void i2c_gpio_scl_set(struct i2c_gpio_bus *bus, int bit)
|
||||
{
|
||||
struct gpio_desc *scl = &bus->gpios[PIN_SCL];
|
||||
ulong flags = GPIOD_IS_OUT;
|
||||
|
||||
if (bit)
|
||||
|
|
@ -56,65 +65,60 @@ static void i2c_gpio_scl_set(struct gpio_desc *scl, int bit)
|
|||
dm_gpio_set_dir_flags(scl, flags);
|
||||
}
|
||||
|
||||
static void i2c_gpio_write_bit(struct gpio_desc *scl, struct gpio_desc *sda,
|
||||
int delay, uchar bit)
|
||||
static void i2c_gpio_write_bit(struct i2c_gpio_bus *bus, int delay, uchar bit)
|
||||
{
|
||||
i2c_gpio_scl_set(scl, 0);
|
||||
bus->set_scl(bus, 0);
|
||||
udelay(delay);
|
||||
i2c_gpio_sda_set(sda, bit);
|
||||
bus->set_sda(bus, bit);
|
||||
udelay(delay);
|
||||
i2c_gpio_scl_set(scl, 1);
|
||||
bus->set_scl(bus, 1);
|
||||
udelay(2 * delay);
|
||||
}
|
||||
|
||||
static int i2c_gpio_read_bit(struct gpio_desc *scl, struct gpio_desc *sda,
|
||||
int delay)
|
||||
static int i2c_gpio_read_bit(struct i2c_gpio_bus *bus, int delay)
|
||||
{
|
||||
int value;
|
||||
|
||||
i2c_gpio_scl_set(scl, 1);
|
||||
bus->set_scl(bus, 1);
|
||||
udelay(delay);
|
||||
value = i2c_gpio_sda_get(sda);
|
||||
value = bus->get_sda(bus);
|
||||
udelay(delay);
|
||||
i2c_gpio_scl_set(scl, 0);
|
||||
bus->set_scl(bus, 0);
|
||||
udelay(2 * delay);
|
||||
|
||||
return value;
|
||||
}
|
||||
|
||||
/* START: High -> Low on SDA while SCL is High */
|
||||
static void i2c_gpio_send_start(struct gpio_desc *scl, struct gpio_desc *sda,
|
||||
int delay)
|
||||
static void i2c_gpio_send_start(struct i2c_gpio_bus *bus, int delay)
|
||||
{
|
||||
udelay(delay);
|
||||
i2c_gpio_sda_set(sda, 1);
|
||||
bus->set_sda(bus, 1);
|
||||
udelay(delay);
|
||||
i2c_gpio_scl_set(scl, 1);
|
||||
bus->set_scl(bus, 1);
|
||||
udelay(delay);
|
||||
i2c_gpio_sda_set(sda, 0);
|
||||
bus->set_sda(bus, 0);
|
||||
udelay(delay);
|
||||
}
|
||||
|
||||
/* STOP: Low -> High on SDA while SCL is High */
|
||||
static void i2c_gpio_send_stop(struct gpio_desc *scl, struct gpio_desc *sda,
|
||||
int delay)
|
||||
static void i2c_gpio_send_stop(struct i2c_gpio_bus *bus, int delay)
|
||||
{
|
||||
i2c_gpio_scl_set(scl, 0);
|
||||
bus->set_scl(bus, 0);
|
||||
udelay(delay);
|
||||
i2c_gpio_sda_set(sda, 0);
|
||||
bus->set_sda(bus, 0);
|
||||
udelay(delay);
|
||||
i2c_gpio_scl_set(scl, 1);
|
||||
bus->set_scl(bus, 1);
|
||||
udelay(delay);
|
||||
i2c_gpio_sda_set(sda, 1);
|
||||
bus->set_sda(bus, 1);
|
||||
udelay(delay);
|
||||
}
|
||||
|
||||
/* ack should be I2C_ACK or I2C_NOACK */
|
||||
static void i2c_gpio_send_ack(struct gpio_desc *scl, struct gpio_desc *sda,
|
||||
int delay, int ack)
|
||||
static void i2c_gpio_send_ack(struct i2c_gpio_bus *bus, int delay, int ack)
|
||||
{
|
||||
i2c_gpio_write_bit(scl, sda, delay, ack);
|
||||
i2c_gpio_scl_set(scl, 0);
|
||||
i2c_gpio_write_bit(bus, delay, ack);
|
||||
bus->set_scl(bus, 0);
|
||||
udelay(delay);
|
||||
}
|
||||
|
||||
|
|
@ -123,44 +127,41 @@ static void i2c_gpio_send_ack(struct gpio_desc *scl, struct gpio_desc *sda,
|
|||
* to clock any confused device back into an idle state. Also send a
|
||||
* <stop> at the end of the sequence for belts & suspenders.
|
||||
*/
|
||||
static void i2c_gpio_send_reset(struct gpio_desc *scl, struct gpio_desc *sda,
|
||||
int delay)
|
||||
static void i2c_gpio_send_reset(struct i2c_gpio_bus *bus, int delay)
|
||||
{
|
||||
int j;
|
||||
|
||||
for (j = 0; j < 9; j++)
|
||||
i2c_gpio_write_bit(scl, sda, delay, 1);
|
||||
i2c_gpio_write_bit(bus, delay, 1);
|
||||
|
||||
i2c_gpio_send_stop(scl, sda, delay);
|
||||
i2c_gpio_send_stop(bus, delay);
|
||||
}
|
||||
|
||||
/* Set sda high with low clock, before reading slave data */
|
||||
static void i2c_gpio_sda_high(struct gpio_desc *scl, struct gpio_desc *sda,
|
||||
int delay)
|
||||
static void i2c_gpio_sda_high(struct i2c_gpio_bus *bus, int delay)
|
||||
{
|
||||
i2c_gpio_scl_set(scl, 0);
|
||||
bus->set_scl(bus, 0);
|
||||
udelay(delay);
|
||||
i2c_gpio_sda_set(sda, 1);
|
||||
bus->set_sda(bus, 1);
|
||||
udelay(delay);
|
||||
}
|
||||
|
||||
/* Send 8 bits and look for an acknowledgement */
|
||||
static int i2c_gpio_write_byte(struct gpio_desc *scl, struct gpio_desc *sda,
|
||||
int delay, uchar data)
|
||||
static int i2c_gpio_write_byte(struct i2c_gpio_bus *bus, int delay, uchar data)
|
||||
{
|
||||
int j;
|
||||
int nack;
|
||||
|
||||
for (j = 0; j < 8; j++) {
|
||||
i2c_gpio_write_bit(scl, sda, delay, data & 0x80);
|
||||
i2c_gpio_write_bit(bus, delay, data & 0x80);
|
||||
data <<= 1;
|
||||
}
|
||||
|
||||
udelay(delay);
|
||||
|
||||
/* Look for an <ACK>(negative logic) and return it */
|
||||
i2c_gpio_sda_high(scl, sda, delay);
|
||||
nack = i2c_gpio_read_bit(scl, sda, delay);
|
||||
i2c_gpio_sda_high(bus, delay);
|
||||
nack = i2c_gpio_read_bit(bus, delay);
|
||||
|
||||
return nack; /* not a nack is an ack */
|
||||
}
|
||||
|
|
@ -169,31 +170,29 @@ static int i2c_gpio_write_byte(struct gpio_desc *scl, struct gpio_desc *sda,
|
|||
* if ack == I2C_ACK, ACK the byte so can continue reading, else
|
||||
* send I2C_NOACK to end the read.
|
||||
*/
|
||||
static uchar i2c_gpio_read_byte(struct gpio_desc *scl, struct gpio_desc *sda,
|
||||
int delay, int ack)
|
||||
static uchar i2c_gpio_read_byte(struct i2c_gpio_bus *bus, int delay, int ack)
|
||||
{
|
||||
int data;
|
||||
int j;
|
||||
|
||||
i2c_gpio_sda_high(scl, sda, delay);
|
||||
i2c_gpio_sda_high(bus, delay);
|
||||
data = 0;
|
||||
for (j = 0; j < 8; j++) {
|
||||
data <<= 1;
|
||||
data |= i2c_gpio_read_bit(scl, sda, delay);
|
||||
data |= i2c_gpio_read_bit(bus, delay);
|
||||
}
|
||||
i2c_gpio_send_ack(scl, sda, delay, ack);
|
||||
i2c_gpio_send_ack(bus, delay, ack);
|
||||
|
||||
return data;
|
||||
}
|
||||
|
||||
/* send start and the slave chip address */
|
||||
int i2c_send_slave_addr(struct gpio_desc *scl, struct gpio_desc *sda, int delay,
|
||||
uchar chip)
|
||||
int i2c_send_slave_addr(struct i2c_gpio_bus *bus, int delay, uchar chip)
|
||||
{
|
||||
i2c_gpio_send_start(scl, sda, delay);
|
||||
i2c_gpio_send_start(bus, delay);
|
||||
|
||||
if (i2c_gpio_write_byte(scl, sda, delay, chip)) {
|
||||
i2c_gpio_send_stop(scl, sda, delay);
|
||||
if (i2c_gpio_write_byte(bus, delay, chip)) {
|
||||
i2c_gpio_send_stop(bus, delay);
|
||||
return -EIO;
|
||||
}
|
||||
|
||||
|
|
@ -204,29 +203,27 @@ static int i2c_gpio_write_data(struct i2c_gpio_bus *bus, uchar chip,
|
|||
uchar *buffer, int len,
|
||||
bool end_with_repeated_start)
|
||||
{
|
||||
struct gpio_desc *scl = &bus->gpios[PIN_SCL];
|
||||
struct gpio_desc *sda = &bus->gpios[PIN_SDA];
|
||||
unsigned int delay = bus->udelay;
|
||||
int failures = 0;
|
||||
|
||||
debug("%s: chip %x buffer %p len %d\n", __func__, chip, buffer, len);
|
||||
|
||||
if (i2c_send_slave_addr(scl, sda, delay, chip << 1)) {
|
||||
if (i2c_send_slave_addr(bus, delay, chip << 1)) {
|
||||
debug("i2c_write, no chip responded %02X\n", chip);
|
||||
return -EIO;
|
||||
}
|
||||
|
||||
while (len-- > 0) {
|
||||
if (i2c_gpio_write_byte(scl, sda, delay, *buffer++))
|
||||
if (i2c_gpio_write_byte(bus, delay, *buffer++))
|
||||
failures++;
|
||||
}
|
||||
|
||||
if (!end_with_repeated_start) {
|
||||
i2c_gpio_send_stop(scl, sda, delay);
|
||||
i2c_gpio_send_stop(bus, delay);
|
||||
return failures;
|
||||
}
|
||||
|
||||
if (i2c_send_slave_addr(scl, sda, delay, (chip << 1) | 0x1)) {
|
||||
if (i2c_send_slave_addr(bus, delay, (chip << 1) | 0x1)) {
|
||||
debug("i2c_write, no chip responded %02X\n", chip);
|
||||
return -EIO;
|
||||
}
|
||||
|
|
@ -237,16 +234,14 @@ static int i2c_gpio_write_data(struct i2c_gpio_bus *bus, uchar chip,
|
|||
static int i2c_gpio_read_data(struct i2c_gpio_bus *bus, uchar chip,
|
||||
uchar *buffer, int len)
|
||||
{
|
||||
struct gpio_desc *scl = &bus->gpios[PIN_SCL];
|
||||
struct gpio_desc *sda = &bus->gpios[PIN_SDA];
|
||||
unsigned int delay = bus->udelay;
|
||||
|
||||
debug("%s: chip %x buffer: %p len %d\n", __func__, chip, buffer, len);
|
||||
|
||||
while (len-- > 0)
|
||||
*buffer++ = i2c_gpio_read_byte(scl, sda, delay, len == 0);
|
||||
*buffer++ = i2c_gpio_read_byte(bus, delay, len == 0);
|
||||
|
||||
i2c_gpio_send_stop(scl, sda, delay);
|
||||
i2c_gpio_send_stop(bus, delay);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
|
@ -277,14 +272,12 @@ static int i2c_gpio_xfer(struct udevice *dev, struct i2c_msg *msg, int nmsgs)
|
|||
static int i2c_gpio_probe(struct udevice *dev, uint chip, uint chip_flags)
|
||||
{
|
||||
struct i2c_gpio_bus *bus = dev_get_priv(dev);
|
||||
struct gpio_desc *scl = &bus->gpios[PIN_SCL];
|
||||
struct gpio_desc *sda = &bus->gpios[PIN_SDA];
|
||||
unsigned int delay = bus->udelay;
|
||||
int ret;
|
||||
|
||||
i2c_gpio_send_start(scl, sda, delay);
|
||||
ret = i2c_gpio_write_byte(scl, sda, delay, (chip << 1) | 0);
|
||||
i2c_gpio_send_stop(scl, sda, delay);
|
||||
i2c_gpio_send_start(bus, delay);
|
||||
ret = i2c_gpio_write_byte(bus, delay, (chip << 1) | 0);
|
||||
i2c_gpio_send_stop(bus, delay);
|
||||
|
||||
debug("%s: bus: %d (%s) chip: %x flags: %x ret: %d\n",
|
||||
__func__, dev->seq, dev->name, chip, chip_flags, ret);
|
||||
|
|
@ -295,12 +288,10 @@ static int i2c_gpio_probe(struct udevice *dev, uint chip, uint chip_flags)
|
|||
static int i2c_gpio_set_bus_speed(struct udevice *dev, unsigned int speed_hz)
|
||||
{
|
||||
struct i2c_gpio_bus *bus = dev_get_priv(dev);
|
||||
struct gpio_desc *scl = &bus->gpios[PIN_SCL];
|
||||
struct gpio_desc *sda = &bus->gpios[PIN_SDA];
|
||||
|
||||
bus->udelay = 1000000 / (speed_hz << 2);
|
||||
|
||||
i2c_gpio_send_reset(scl, sda, bus->udelay);
|
||||
i2c_gpio_send_reset(bus, bus->udelay);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
|
@ -335,6 +326,10 @@ static int i2c_gpio_ofdata_to_platdata(struct udevice *dev)
|
|||
bus->udelay = fdtdec_get_int(blob, node, "i2c-gpio,delay-us",
|
||||
DEFAULT_UDELAY);
|
||||
|
||||
bus->get_sda = i2c_gpio_sda_get;
|
||||
bus->set_sda = i2c_gpio_sda_set;
|
||||
bus->set_scl = i2c_gpio_scl_set;
|
||||
|
||||
return 0;
|
||||
error:
|
||||
pr_err("Can't get %s gpios! Error: %d", dev->name, ret);
|
||||
|
|
|
|||
Loading…
Add table
Reference in a new issue