Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 720d5ce9 authored by Eddie James's avatar Eddie James Committed by Wolfram Sang
Browse files

i2c: fsi: Add bus recovery 



Bus recovery should reset the bus with the standard i2c recovery
procedure. Populate the necessary fields so that the standard procedure
can perform the reset.

Signed-off-by: default avatarEddie James <eajames@linux.vnet.ibm.com>
Tested-by: default avatarJoel Stanley <joel@jms.id.au>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent f4cdc319

drivers/i2c/busses/i2c-fsi.c

+132 −0
Original line number Diff line number Diff line
@@ -326,6 +326,115 @@ static int fsi_i2c_read_fifo(struct fsi_i2c_port *port, struct i2c_msg *msg, 
	return 0;

}



static int fsi_i2c_get_scl(struct i2c_adapter *adap)

{

	u32 stat = 0;

	struct fsi_i2c_port *port = adap->algo_data;

	struct fsi_i2c_master *i2c = port->master;



	fsi_i2c_read_reg(i2c->fsi, I2C_FSI_STAT, &stat);



	return !!(stat & I2C_STAT_SCL_IN);

}



static void fsi_i2c_set_scl(struct i2c_adapter *adap, int val)

{

	u32 dummy = 0;

	struct fsi_i2c_port *port = adap->algo_data;

	struct fsi_i2c_master *i2c = port->master;



	if (val)

		fsi_i2c_write_reg(i2c->fsi, I2C_FSI_SET_SCL, &dummy);

	else

		fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_SCL, &dummy);

}



static int fsi_i2c_get_sda(struct i2c_adapter *adap)

{

	u32 stat = 0;

	struct fsi_i2c_port *port = adap->algo_data;

	struct fsi_i2c_master *i2c = port->master;



	fsi_i2c_read_reg(i2c->fsi, I2C_FSI_STAT, &stat);



	return !!(stat & I2C_STAT_SDA_IN);

}



static void fsi_i2c_set_sda(struct i2c_adapter *adap, int val)

{

	u32 dummy = 0;

	struct fsi_i2c_port *port = adap->algo_data;

	struct fsi_i2c_master *i2c = port->master;



	if (val)

		fsi_i2c_write_reg(i2c->fsi, I2C_FSI_SET_SDA, &dummy);

	else

		fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_SDA, &dummy);

}



static void fsi_i2c_prepare_recovery(struct i2c_adapter *adap)

{

	int rc;

	u32 mode;

	struct fsi_i2c_port *port = adap->algo_data;

	struct fsi_i2c_master *i2c = port->master;



	rc = fsi_i2c_read_reg(i2c->fsi, I2C_FSI_MODE, &mode);

	if (rc)

		return;



	mode |= I2C_MODE_DIAG;

	fsi_i2c_write_reg(i2c->fsi, I2C_FSI_MODE, &mode);

}



static void fsi_i2c_unprepare_recovery(struct i2c_adapter *adap)

{

	int rc;

	u32 mode;

	struct fsi_i2c_port *port = adap->algo_data;

	struct fsi_i2c_master *i2c = port->master;



	rc = fsi_i2c_read_reg(i2c->fsi, I2C_FSI_MODE, &mode);

	if (rc)

		return;



	mode &= ~I2C_MODE_DIAG;

	fsi_i2c_write_reg(i2c->fsi, I2C_FSI_MODE, &mode);

}



static int fsi_i2c_reset_bus(struct fsi_i2c_master *i2c,

			     struct fsi_i2c_port *port)

{

	int rc;

	u32 stat, dummy = 0;



	/* force bus reset, ignore errors */

	i2c_recover_bus(&port->adapter);



	/* reset errors */

	rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_ERR, &dummy);

	if (rc)

		return rc;



	/* wait for command complete */

	usleep_range(I2C_RESET_SLEEP_MIN_US, I2C_RESET_SLEEP_MAX_US);



	rc = fsi_i2c_read_reg(i2c->fsi, I2C_FSI_STAT, &stat);

	if (rc)

		return rc;



	if (stat & I2C_STAT_CMD_COMP)

		return 0;



	/* failed to get command complete; reset engine again */

	rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_I2C, &dummy);

	if (rc)

		return rc;



	/* re-init engine again */

	return fsi_i2c_dev_init(i2c);

}



static int fsi_i2c_reset_engine(struct fsi_i2c_master *i2c, u16 port)

{

	int rc;
@@ -368,6 +477,7 @@ static int fsi_i2c_abort(struct fsi_i2c_port *port, u32 status) 
	int rc;

	unsigned long start;

	u32 cmd = I2C_CMD_WITH_STOP;

	u32 stat;

	struct fsi_i2c_master *i2c = port->master;

	struct fsi_device *fsi = i2c->fsi;
@@ -375,6 +485,17 @@ static int fsi_i2c_abort(struct fsi_i2c_port *port, u32 status) 
	if (rc)

		return rc;



	rc = fsi_i2c_read_reg(fsi, I2C_FSI_STAT, &stat);

	if (rc)

		return rc;



	/* if sda is low, peform full bus reset */

	if (!(stat & I2C_STAT_SDA_IN)) {

		rc = fsi_i2c_reset_bus(i2c, port);

		if (rc)

			return rc;

	}



	/* skip final stop command for these errors */

	if (status & (I2C_STAT_PARITY | I2C_STAT_LOST_ARB | I2C_STAT_STOP_ERR))

		return 0;
@@ -522,6 +643,16 @@ static u32 fsi_i2c_functionality(struct i2c_adapter *adap) 
		I2C_FUNC_SMBUS_EMUL | I2C_FUNC_SMBUS_BLOCK_DATA;

}



static struct i2c_bus_recovery_info fsi_i2c_bus_recovery_info = {

	.recover_bus = i2c_generic_scl_recovery,

	.get_scl = fsi_i2c_get_scl,

	.set_scl = fsi_i2c_set_scl,

	.get_sda = fsi_i2c_get_sda,

	.set_sda = fsi_i2c_set_sda,

	.prepare_recovery = fsi_i2c_prepare_recovery,

	.unprepare_recovery = fsi_i2c_unprepare_recovery,

};



static const struct i2c_algorithm fsi_i2c_algorithm = {

	.master_xfer = fsi_i2c_xfer,

	.functionality = fsi_i2c_functionality,
@@ -564,6 +695,7 @@ static int fsi_i2c_probe(struct device *dev) 
		port->adapter.dev.of_node = np;

		port->adapter.dev.parent = dev;

		port->adapter.algo = &fsi_i2c_algorithm;

		port->adapter.bus_recovery_info = &fsi_i2c_bus_recovery_info;

		port->adapter.algo_data = port;



		snprintf(port->adapter.name, sizeof(port->adapter.name),